Commit Graph

20729 Commits

Author SHA1 Message Date
Paolo Bonzini
e7011c5d17 KVM PPC update for 5.5
* Add capability to tell userspace whether we can single-step the guest.
 
 * Improve the allocation of XIVE virtual processor IDs, to reduce the
   risk of running out of IDs when running many VMs on POWER9.
 
 * Rewrite interrupt synthesis code to deliver interrupts in virtual
   mode when appropriate.
 
 * Minor cleanups and improvements.
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Merge tag 'kvm-ppc-next-5.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into HEAD

KVM PPC update for 5.5

* Add capability to tell userspace whether we can single-step the guest.

* Improve the allocation of XIVE virtual processor IDs, to reduce the
  risk of running out of IDs when running many VMs on POWER9.

* Rewrite interrupt synthesis code to deliver interrupts in virtual
  mode when appropriate.

* Minor cleanups and improvements.
2019-11-01 00:35:55 +01:00
Sean Christopherson
149487bdac KVM: Add separate helper for putting borrowed reference to kvm
Add a new helper, kvm_put_kvm_no_destroy(), to handle putting a borrowed
reference[*] to the VM when installing a new file descriptor fails.  KVM
expects the refcount to remain valid in this case, as the in-progress
ioctl() has an explicit reference to the VM.  The primary motiviation
for the helper is to document that the 'kvm' pointer is still valid
after putting the borrowed reference, e.g. to document that doing
mutex(&kvm->lock) immediately after putting a ref to kvm isn't broken.

[*] When exposing a new object to userspace via a file descriptor, e.g.
    a new vcpu, KVM grabs a reference to itself (the VM) prior to making
    the object visible to userspace to avoid prematurely freeing the VM
    in the scenario where userspace immediately closes file descriptor.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-10-22 15:48:30 +02:00
Nicholas Piggin
55d7004299 KVM: PPC: Book3S HV: Reject mflags=2 (LPCR[AIL]=2) ADDR_TRANS_MODE mode
AIL=2 mode has no known users, so is not well tested or supported.
Disallow guests from selecting this mode because it may become
deprecated in future versions of the architecture.

This policy decision is not left to QEMU because KVM support is
required for AIL=2 (when injecting interrupts).

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-10-22 16:29:02 +11:00
Nicholas Piggin
6a13cb0c37 KVM: PPC: Book3S HV: Implement LPCR[AIL]=3 mode for injected interrupts
kvmppc_inject_interrupt does not implement LPCR[AIL]!=0 modes, which
can result in the guest receiving interrupts as if LPCR[AIL]=0
contrary to the ISA.

In practice, Linux guests cope with this deviation, but it should be
fixed.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-10-22 16:29:02 +11:00
Nicholas Piggin
268f4ef995 KVM: PPC: Book3S HV: Reuse kvmppc_inject_interrupt for async guest delivery
This consolidates the HV interrupt delivery logic into one place.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-10-22 16:29:02 +11:00
Nicholas Piggin
87a45e07a5 KVM: PPC: Book3S: Replace reset_msr mmu op with inject_interrupt arch op
reset_msr sets the MSR for interrupt injection, but it's cleaner and
more flexible to provide a single op to set both MSR and PC for the
interrupt.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-10-22 16:29:02 +11:00
Nicholas Piggin
9ee6471eb9 KVM: PPC: Book3S: Define and use SRR1_MSR_BITS
Acked-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-10-22 16:29:02 +11:00
Greg Kurz
efe5ddcae4 KVM: PPC: Book3S HV: XIVE: Allow userspace to set the # of VPs
Add a new attribute to both XIVE and XICS-on-XIVE KVM devices so that
userspace can tell how many interrupt servers it needs. If a VM needs
less than the current default of KVM_MAX_VCPUS (2048), we can allocate
less VPs in OPAL. Combined with a core stride (VSMT) that matches the
number of guest threads per core, this may substantially increases the
number of VMs that can run concurrently with an in-kernel XIVE device.

Since the legacy XIVE KVM device is exposed to userspace through the
XICS KVM API, a new attribute group is added to it for this purpose.
While here, fix the syntax of the existing KVM_DEV_XICS_GRP_SOURCES
in the XICS documentation.

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-10-22 16:29:02 +11:00
Greg Kurz
062cfab706 KVM: PPC: Book3S HV: XIVE: Make VP block size configurable
The XIVE VP is an internal structure which allow the XIVE interrupt
controller to maintain the interrupt context state of vCPUs non
dispatched on HW threads.

When a guest is started, the XIVE KVM device allocates a block of
XIVE VPs in OPAL, enough to accommodate the highest possible vCPU
id KVM_MAX_VCPU_ID (16384) packed down to KVM_MAX_VCPUS (2048).
With a guest's core stride of 8 and a threading mode of 1 (QEMU's
default), a VM must run at least 256 vCPUs to actually need such a
range of VPs.

A POWER9 system has a limited XIVE VP space : 512k and KVM is
currently wasting this HW resource with large VP allocations,
especially since a typical VM likely runs with a lot less vCPUs.

Make the size of the VP block configurable. Add an nr_servers
field to the XIVE structure and a function to set it for this
purpose.

Split VP allocation out of the device create function. Since the
VP block isn't used before the first vCPU connects to the XIVE KVM
device, allocation is now performed by kvmppc_xive_connect_vcpu().
This gives the opportunity to set nr_servers in between:

          kvmppc_xive_create() / kvmppc_xive_native_create()
                               .
                               .
                     kvmppc_xive_set_nr_servers()
                               .
                               .
    kvmppc_xive_connect_vcpu() / kvmppc_xive_native_connect_vcpu()

The connect_vcpu() functions check that the vCPU id is below nr_servers
and if it is the first vCPU they allocate the VP block. This is protected
against a concurrent update of nr_servers by kvmppc_xive_set_nr_servers()
with the xive->lock mutex.

Also, the block is allocated once for the device lifetime: nr_servers
should stay constant otherwise connect_vcpu() could generate a boggus
VP id and likely crash OPAL. It is thus forbidden to update nr_servers
once the block is allocated.

If the VP allocation fail, return ENOSPC which seems more appropriate to
report the depletion of system wide HW resource than ENOMEM or ENXIO.

A VM using a stride of 8 and 1 thread per core with 32 vCPUs would hence
only need 256 VPs instead of 2048. If the stride is set to match the number
of threads per core, this goes further down to 32.

This will be exposed to userspace by a subsequent patch.

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-10-22 16:29:02 +11:00
Greg Kurz
8db29ea239 KVM: PPC: Book3S HV: XIVE: Compute the VP id in a common helper
Reduce code duplication by consolidating the checking of vCPU ids and VP
ids to a common helper used by both legacy and native XIVE KVM devices.
And explain the magic with a comment.

Signed-off-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-10-22 16:29:02 +11:00
Greg Kurz
8a4e7597ba KVM: PPC: Book3S HV: XIVE: Show VP id in debugfs
Print out the VP id of each connected vCPU, this allow to see:
- the VP block base in which OPAL encodes information that may be
  useful when debugging
- the packed vCPU id which may differ from the raw vCPU id if the
  latter is >= KVM_MAX_VCPUS (2048)

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-10-22 16:29:02 +11:00
Greg Kurz
e7d71c9430 KVM: PPC: Book3S HV: XIVE: Set kvm->arch.xive when VPs are allocated
If we cannot allocate the XIVE VPs in OPAL, the creation of a XIVE or
XICS-on-XIVE device is aborted as expected, but we leave kvm->arch.xive
set forever since the release method isn't called in this case. Any
subsequent tentative to create a XIVE or XICS-on-XIVE for this VM will
thus always fail (DoS). This is a problem for QEMU since it destroys
and re-creates these devices when the VM is reset: the VM would be
restricted to using the much slower emulated XIVE or XICS forever.

As an alternative to adding rollback, do not assign kvm->arch.xive before
making sure the XIVE VPs are allocated in OPAL.

Cc: stable@vger.kernel.org # v5.2
Fixes: 5422e95103 ("KVM: PPC: Book3S HV: XIVE: Replace the 'destroy' method by a 'release' method")
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-10-22 16:29:01 +11:00
Leonardo Bras
f41c4989c8 KVM: PPC: E500: Replace current->mm by kvm->mm
Given that in kvm_create_vm() there is:
kvm->mm = current->mm;

And that on every kvm_*_ioctl we have:
if (kvm->mm != current->mm)
	return -EIO;

I see no reason to keep using current->mm instead of kvm->mm.

By doing so, we would reduce the use of 'global' variables on code, relying
more in the contents of kvm struct.

Signed-off-by: Leonardo Bras <leonardo@linux.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-10-22 16:29:01 +11:00
Leonardo Bras
258ed7d028 KVM: PPC: Reduce calls to get current->mm by storing the value locally
Reduces the number of calls to get_current() in order to get the value of
current->mm by doing it once and storing the value, since it is not
supposed to change inside the same process).

Signed-off-by: Leonardo Bras <leonardo@linux.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-10-22 16:29:01 +11:00
Fabiano Rosas
1a9167a214 KVM: PPC: Report single stepping capability
When calling the KVM_SET_GUEST_DEBUG ioctl, userspace might request
the next instruction to be single stepped via the
KVM_GUESTDBG_SINGLESTEP control bit of the kvm_guest_debug structure.

This patch adds the KVM_CAP_PPC_GUEST_DEBUG_SSTEP capability in order
to inform userspace about the state of single stepping support.

We currently don't have support for guest single stepping implemented
in Book3S HV so the capability is only present for Book3S PR and
BookE.

Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-10-21 15:55:22 +11:00
Greg Kurz
12ade69c1e KVM: PPC: Book3S HV: XIVE: Ensure VP isn't already in use
Connecting a vCPU to a XIVE KVM device means establishing a 1:1
association between a vCPU id and the offset (VP id) of a VP
structure within a fixed size block of VPs. We currently try to
enforce the 1:1 relationship by checking that a vCPU with the
same id isn't already connected. This is good but unfortunately
not enough because we don't map VP ids to raw vCPU ids but to
packed vCPU ids, and the packing function kvmppc_pack_vcpu_id()
isn't bijective by design. We got away with it because QEMU passes
vCPU ids that fit well in the packing pattern. But nothing prevents
userspace to come up with a forged vCPU id resulting in a packed id
collision which causes the KVM device to associate two vCPUs to the
same VP. This greatly confuses the irq layer and ultimately crashes
the kernel, as shown below.

Example: a guest with 1 guest thread per core, a core stride of
8 and 300 vCPUs has vCPU ids 0,8,16...2392. If QEMU is patched to
inject at some point an invalid vCPU id 348, which is the packed
version of itself and 2392, we get:

genirq: Flags mismatch irq 199. 00010000 (kvm-2-2392) vs. 00010000 (kvm-2-348)
CPU: 24 PID: 88176 Comm: qemu-system-ppc Not tainted 5.3.0-xive-nr-servers-5.3-gku+ #38
Call Trace:
[c000003f7f9937e0] [c000000000c0110c] dump_stack+0xb0/0xf4 (unreliable)
[c000003f7f993820] [c0000000001cb480] __setup_irq+0xa70/0xad0
[c000003f7f9938d0] [c0000000001cb75c] request_threaded_irq+0x13c/0x260
[c000003f7f993940] [c00800000d44e7ac] kvmppc_xive_attach_escalation+0x104/0x270 [kvm]
[c000003f7f9939d0] [c00800000d45013c] kvmppc_xive_connect_vcpu+0x424/0x620 [kvm]
[c000003f7f993ac0] [c00800000d444428] kvm_arch_vcpu_ioctl+0x260/0x448 [kvm]
[c000003f7f993b90] [c00800000d43593c] kvm_vcpu_ioctl+0x154/0x7c8 [kvm]
[c000003f7f993d00] [c0000000004840f0] do_vfs_ioctl+0xe0/0xc30
[c000003f7f993db0] [c000000000484d44] ksys_ioctl+0x104/0x120
[c000003f7f993e00] [c000000000484d88] sys_ioctl+0x28/0x80
[c000003f7f993e20] [c00000000000b278] system_call+0x5c/0x68
xive-kvm: Failed to request escalation interrupt for queue 0 of VCPU 2392
------------[ cut here ]------------
remove_proc_entry: removing non-empty directory 'irq/199', leaking at least 'kvm-2-348'
WARNING: CPU: 24 PID: 88176 at /home/greg/Work/linux/kernel-kvm-ppc/fs/proc/generic.c:684 remove_proc_entry+0x1ec/0x200
Modules linked in: kvm_hv kvm dm_mod vhost_net vhost tap xt_CHECKSUM iptable_mangle xt_MASQUERADE iptable_nat nf_nat xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ipt_REJECT nf_reject_ipv4 tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter squashfs loop fuse i2c_dev sg ofpart ocxl powernv_flash at24 xts mtd uio_pdrv_genirq vmx_crypto opal_prd ipmi_powernv uio ipmi_devintf ipmi_msghandler ibmpowernv ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ip_tables ext4 mbcache jbd2 raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor xor async_tx raid6_pq libcrc32c raid1 raid0 linear sd_mod ast i2c_algo_bit drm_vram_helper ttm drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops drm ahci libahci libata tg3 drm_panel_orientation_quirks [last unloaded: kvm]
CPU: 24 PID: 88176 Comm: qemu-system-ppc Not tainted 5.3.0-xive-nr-servers-5.3-gku+ #38
NIP:  c00000000053b0cc LR: c00000000053b0c8 CTR: c0000000000ba3b0
REGS: c000003f7f9934b0 TRAP: 0700   Not tainted  (5.3.0-xive-nr-servers-5.3-gku+)
MSR:  9000000000029033 <SF,HV,EE,ME,IR,DR,RI,LE>  CR: 48228222  XER: 20040000
CFAR: c000000000131a50 IRQMASK: 0
GPR00: c00000000053b0c8 c000003f7f993740 c0000000015ec500 0000000000000057
GPR04: 0000000000000001 0000000000000000 000049fb98484262 0000000000001bcf
GPR08: 0000000000000007 0000000000000007 0000000000000001 9000000000001033
GPR12: 0000000000008000 c000003ffffeb800 0000000000000000 000000012f4ce5a1
GPR16: 000000012ef5a0c8 0000000000000000 000000012f113bb0 0000000000000000
GPR20: 000000012f45d918 c000003f863758b0 c000003f86375870 0000000000000006
GPR24: c000003f86375a30 0000000000000007 c0002039373d9020 c0000000014c4a48
GPR28: 0000000000000001 c000003fe62a4f6b c00020394b2e9fab c000003fe62a4ec0
NIP [c00000000053b0cc] remove_proc_entry+0x1ec/0x200
LR [c00000000053b0c8] remove_proc_entry+0x1e8/0x200
Call Trace:
[c000003f7f993740] [c00000000053b0c8] remove_proc_entry+0x1e8/0x200 (unreliable)
[c000003f7f9937e0] [c0000000001d3654] unregister_irq_proc+0x114/0x150
[c000003f7f993880] [c0000000001c6284] free_desc+0x54/0xb0
[c000003f7f9938c0] [c0000000001c65ec] irq_free_descs+0xac/0x100
[c000003f7f993910] [c0000000001d1ff8] irq_dispose_mapping+0x68/0x80
[c000003f7f993940] [c00800000d44e8a4] kvmppc_xive_attach_escalation+0x1fc/0x270 [kvm]
[c000003f7f9939d0] [c00800000d45013c] kvmppc_xive_connect_vcpu+0x424/0x620 [kvm]
[c000003f7f993ac0] [c00800000d444428] kvm_arch_vcpu_ioctl+0x260/0x448 [kvm]
[c000003f7f993b90] [c00800000d43593c] kvm_vcpu_ioctl+0x154/0x7c8 [kvm]
[c000003f7f993d00] [c0000000004840f0] do_vfs_ioctl+0xe0/0xc30
[c000003f7f993db0] [c000000000484d44] ksys_ioctl+0x104/0x120
[c000003f7f993e00] [c000000000484d88] sys_ioctl+0x28/0x80
[c000003f7f993e20] [c00000000000b278] system_call+0x5c/0x68
Instruction dump:
2c230000 41820008 3923ff78 e8e900a0 3c82ff69 3c62ff8d 7fa6eb78 7fc5f378
3884f080 3863b948 4bbf6925 60000000 <0fe00000> 4bffff7c fba10088 4bbf6e41
---[ end trace b925b67a74a1d8d1 ]---
BUG: Kernel NULL pointer dereference at 0x00000010
Faulting instruction address: 0xc00800000d44fc04
Oops: Kernel access of bad area, sig: 11 [#1]
LE PAGE_SIZE=64K MMU=Radix MMU=Hash SMP NR_CPUS=2048 NUMA PowerNV
Modules linked in: kvm_hv kvm dm_mod vhost_net vhost tap xt_CHECKSUM iptable_mangle xt_MASQUERADE iptable_nat nf_nat xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ipt_REJECT nf_reject_ipv4 tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter squashfs loop fuse i2c_dev sg ofpart ocxl powernv_flash at24 xts mtd uio_pdrv_genirq vmx_crypto opal_prd ipmi_powernv uio ipmi_devintf ipmi_msghandler ibmpowernv ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ip_tables ext4 mbcache jbd2 raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor xor async_tx raid6_pq libcrc32c raid1 raid0 linear sd_mod ast i2c_algo_bit drm_vram_helper ttm drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops drm ahci libahci libata tg3 drm_panel_orientation_quirks [last unloaded: kvm]
CPU: 24 PID: 88176 Comm: qemu-system-ppc Tainted: G        W         5.3.0-xive-nr-servers-5.3-gku+ #38
NIP:  c00800000d44fc04 LR: c00800000d44fc00 CTR: c0000000001cd970
REGS: c000003f7f9938e0 TRAP: 0300   Tainted: G        W          (5.3.0-xive-nr-servers-5.3-gku+)
MSR:  9000000000009033 <SF,HV,EE,ME,IR,DR,RI,LE>  CR: 24228882  XER: 20040000
CFAR: c0000000001cd9ac DAR: 0000000000000010 DSISR: 40000000 IRQMASK: 0
GPR00: c00800000d44fc00 c000003f7f993b70 c00800000d468300 0000000000000000
GPR04: 00000000000000c7 0000000000000000 0000000000000000 c000003ffacd06d8
GPR08: 0000000000000000 c000003ffacd0738 0000000000000000 fffffffffffffffd
GPR12: 0000000000000040 c000003ffffeb800 0000000000000000 000000012f4ce5a1
GPR16: 000000012ef5a0c8 0000000000000000 000000012f113bb0 0000000000000000
GPR20: 000000012f45d918 00007ffffe0d9a80 000000012f4f5df0 000000012ef8c9f8
GPR24: 0000000000000001 0000000000000000 c000003fe4501ed0 c000003f8b1d0000
GPR28: c0000033314689c0 c000003fe4501c00 c000003fe4501e70 c000003fe4501e90
NIP [c00800000d44fc04] kvmppc_xive_cleanup_vcpu+0xfc/0x210 [kvm]
LR [c00800000d44fc00] kvmppc_xive_cleanup_vcpu+0xf8/0x210 [kvm]
Call Trace:
[c000003f7f993b70] [c00800000d44fc00] kvmppc_xive_cleanup_vcpu+0xf8/0x210 [kvm] (unreliable)
[c000003f7f993bd0] [c00800000d450bd4] kvmppc_xive_release+0xdc/0x1b0 [kvm]
[c000003f7f993c30] [c00800000d436a98] kvm_device_release+0xb0/0x110 [kvm]
[c000003f7f993c70] [c00000000046730c] __fput+0xec/0x320
[c000003f7f993cd0] [c000000000164ae0] task_work_run+0x150/0x1c0
[c000003f7f993d30] [c000000000025034] do_notify_resume+0x304/0x440
[c000003f7f993e20] [c00000000000dcc4] ret_from_except_lite+0x70/0x74
Instruction dump:
3bff0008 7fbfd040 419e0054 847e0004 2fa30000 419effec e93d0000 8929203c
2f890000 419effb8 4800821d e8410018 <e9230010> e9490008 9b2a0039 7c0004ac
---[ end trace b925b67a74a1d8d2 ]---

Kernel panic - not syncing: Fatal exception

This affects both XIVE and XICS-on-XIVE devices since the beginning.

Check the VP id instead of the vCPU id when a new vCPU is connected.
The allocation of the XIVE CPU structure in kvmppc_xive_connect_vcpu()
is moved after the check to avoid the need for rollback.

Cc: stable@vger.kernel.org # v4.12+
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-10-15 16:09:11 +11:00
Emmanuel Nicolet
2272905a45 spufs: fix a crash in spufs_create_root()
The spu_fs_context was not set in fc->fs_private, this caused a crash
when accessing ctx->mode in spufs_create_root().

Fixes: d2e0981c3b ("vfs: Convert spufs to use the new mount API")
Signed-off-by: Emmanuel Nicolet <emmanuel.nicolet@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20191008141342.GA266797@gmail.com
2019-10-11 16:57:41 +11:00
Jordan Niethe
7fe4e1176d powerpc/kvm: Fix kvmppc_vcore->in_guest value in kvmhv_switch_to_host
kvmhv_switch_to_host() in arch/powerpc/kvm/book3s_hv_rmhandlers.S
needs to set kvmppc_vcore->in_guest to 0 to signal secondary CPUs to
continue. This happens after resetting the PCR. Before commit
13c7bb3c57 ("powerpc/64s: Set reserved PCR bits"), r0 would always
be 0 before it was stored to kvmppc_vcore->in_guest. However because
of this change in the commit:

          /* Reset PCR */
          ld      r0, VCORE_PCR(r5)
  -       cmpdi   r0, 0
  +       LOAD_REG_IMMEDIATE(r6, PCR_MASK)
  +       cmpld   r0, r6
          beq     18f
  -       li      r0, 0
  -       mtspr   SPRN_PCR, r0
  +       mtspr   SPRN_PCR, r6
   18:
          /* Signal secondary CPUs to continue */
          stb     r0,VCORE_IN_GUEST(r5)

We are no longer comparing r0 against 0 and loading it with 0 if it
contains something else. Hence when we store r0 to
kvmppc_vcore->in_guest, it might not be 0. This means that secondary
CPUs will not be signalled to continue. Those CPUs get stuck and
errors like the following are logged:

    KVM: CPU 1 seems to be stuck
    KVM: CPU 2 seems to be stuck
    KVM: CPU 3 seems to be stuck
    KVM: CPU 4 seems to be stuck
    KVM: CPU 5 seems to be stuck
    KVM: CPU 6 seems to be stuck
    KVM: CPU 7 seems to be stuck

This can be reproduced with:
    $ for i in `seq 1 7` ; do chcpu -d $i ; done ;
    $ taskset -c 0 qemu-system-ppc64 -smp 8,threads=8 \
       -M pseries,accel=kvm,kvm-type=HV -m 1G -nographic -vga none \
       -kernel vmlinux -initrd initrd.cpio.xz

Fix by making sure r0 is 0 before storing it to
kvmppc_vcore->in_guest.

Fixes: 13c7bb3c57 ("powerpc/64s: Set reserved PCR bits")
Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Reviewed-by: Alistair Popple <alistair@popple.id.au>
Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191004025317.19340-1-jniethe5@gmail.com
2019-10-09 17:16:59 +11:00
Laurent Dufour
4ab8a485f7 powerpc/pseries: Remove confusing warning message.
Since commit 1211ee61b4 ("powerpc/pseries: Read TLB Block Invalidate
Characteristics"), a warning message is displayed when booting a guest
on top of KVM:

  lpar: arch/powerpc/platforms/pseries/lpar.c pseries_lpar_read_hblkrm_characteristics Error calling get-system-parameter (0xfffffffd)

This message is displayed because this hypervisor is not supporting
the H_BLOCK_REMOVE hcall and thus is not exposing the corresponding
feature.

Reading the TLB Block Invalidate Characteristics should not be done if
the feature is not exposed.

Fixes: 1211ee61b4 ("powerpc/pseries: Read TLB Block Invalidate Characteristics")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191001132928.72555-1-ldufour@linux.ibm.com
2019-10-09 17:16:59 +11:00
Stephen Rothwell
18217da361 powerpc/64s/radix: Fix build failure with RADIX_MMU=n
After merging the powerpc tree, today's linux-next build (powerpc64
allnoconfig) failed like this:

 arch/powerpc/mm/book3s64/pgtable.c:216:3:
 error: implicit declaration of function 'radix__flush_all_lpid_guest'

radix__flush_all_lpid_guest() is only declared for
CONFIG_PPC_RADIX_MMU which is not set for this build.

Fix it by adding an empty version for the RADIX_MMU=n case, which
should never be called.

Fixes: 99161de3a2 ("powerpc/64s/radix: tidy up TLB flushing code")
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
[mpe: Munge change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190930101342.36c1afa0@canb.auug.org.au
2019-10-09 17:16:58 +11:00
Linus Torvalds
2d00aee21a Kbuild fixes for v5.4
- remove unneeded ar-option and KBUILD_ARFLAGS
 
  - remove long-deprecated SUBDIRS
 
  - fix modpost to suppress false-positive warnings for UML builds
 
  - fix namespace.pl to handle relative paths to ${objtree}, ${srctree}
 
  - make setlocalversion work for /bin/sh
 
  - make header archive reproducible
 
  - fix some Makefiles and documents
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Merge tag 'kbuild-fixes-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

 - remove unneeded ar-option and KBUILD_ARFLAGS

 - remove long-deprecated SUBDIRS

 - fix modpost to suppress false-positive warnings for UML builds

 - fix namespace.pl to handle relative paths to ${objtree}, ${srctree}

 - make setlocalversion work for /bin/sh

 - make header archive reproducible

 - fix some Makefiles and documents

* tag 'kbuild-fixes-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kheaders: make headers archive reproducible
  kbuild: update compile-test header list for v5.4-rc2
  kbuild: two minor updates for Documentation/kbuild/modules.rst
  scripts/setlocalversion: clear local variable to make it work for sh
  namespace: fix namespace.pl script to support relative paths
  video/logo: do not generate unneeded logo C files
  video/logo: remove unneeded *.o pattern from clean-files
  integrity: remove pointless subdir-$(CONFIG_...)
  integrity: remove unneeded, broken attempt to add -fshort-wchar
  modpost: fix static EXPORT_SYMBOL warnings for UML build
  kbuild: correct formatting of header in kbuild module docs
  kbuild: remove SUBDIRS support
  kbuild: remove ar-option and KBUILD_ARFLAGS
2019-10-05 12:56:59 -07:00
Linus Torvalds
b145b0eb20 ARM and x86 bugfixes of all kinds. The most visible one is that migrating
a nested hypervisor has always been busted on Broadwell and newer processors,
 and that has finally been fixed.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM fixes from Paolo Bonzini:
 "ARM and x86 bugfixes of all kinds.

  The most visible one is that migrating a nested hypervisor has always
  been busted on Broadwell and newer processors, and that has finally
  been fixed"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (22 commits)
  KVM: x86: omit "impossible" pmu MSRs from MSR list
  KVM: nVMX: Fix consistency check on injected exception error code
  KVM: x86: omit absent pmu MSRs from MSR list
  selftests: kvm: Fix libkvm build error
  kvm: vmx: Limit guest PMCs to those supported on the host
  kvm: x86, powerpc: do not allow clearing largepages debugfs entry
  KVM: selftests: x86: clarify what is reported on KVM_GET_MSRS failure
  KVM: VMX: Set VMENTER_L1D_FLUSH_NOT_REQUIRED if !X86_BUG_L1TF
  selftests: kvm: add test for dirty logging inside nested guests
  KVM: x86: fix nested guest live migration with PML
  KVM: x86: assign two bits to track SPTE kinds
  KVM: x86: Expose XSAVEERPTR to the guest
  kvm: x86: Enumerate support for CLZERO instruction
  kvm: x86: Use AMD CPUID semantics for AMD vCPUs
  kvm: x86: Improve emulation of CPUID leaves 0BH and 1FH
  KVM: X86: Fix userspace set invalid CR4
  kvm: x86: Fix a spurious -E2BIG in __do_cpuid_func
  KVM: LAPIC: Loosen filter for adaptive tuning of lapic_timer_advance_ns
  KVM: arm/arm64: vgic: Use the appropriate TRACE_INCLUDE_PATH
  arm64: KVM: Kill hyp_alternate_select()
  ...
2019-10-04 11:17:51 -07:00
Masahiro Yamada
13dc8c029c kbuild: remove ar-option and KBUILD_ARFLAGS
Commit 40df759e2b ("kbuild: Fix build with binutils <= 2.19")
introduced ar-option and KBUILD_ARFLAGS to deal with old binutils.

According to Documentation/process/changes.rst, the current minimal
supported version of binutils is 2.21 so you can assume the 'D' option
is always supported. Not only GNU ar but also llvm-ar supports it.

With the 'D' option hard-coded, there is no more user of ar-option
or KBUILD_ARFLAGS.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
2019-10-01 09:20:33 +09:00
Paolo Bonzini
833b45de69 kvm: x86, powerpc: do not allow clearing largepages debugfs entry
The largepages debugfs entry is incremented/decremented as shadow
pages are created or destroyed.  Clearing it will result in an
underflow, which is harmless to KVM but ugly (and could be
misinterpreted by tools that use debugfs information), so make
this particular statistic read-only.

Cc: kvm-ppc@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-30 18:52:00 +02:00
Linus Torvalds
a3c0e7b1fe libnvdimm fixes v5.4-rc1
- Complete the reworks to interoperate with powerpc dynamic huge page sizes
 
 - Fix a crash due to missed accounting for the powerpc 'struct
   page'-memmap mapping granularity.
 
 - Fix badblock initialization for volatile (DRAM emulated) pmem ranges.
 
 - Stop triggering request_key() notifications to userspace when
   NVDIMM-security is disabled / not present.
 
 - Miscellaneous small fixups.
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Merge tag 'libnvdimm-fixes-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

More libnvdimm updates from Dan Williams:

 - Complete the reworks to interoperate with powerpc dynamic huge page
   sizes

 - Fix a crash due to missed accounting for the powerpc 'struct
   page'-memmap mapping granularity

 - Fix badblock initialization for volatile (DRAM emulated) pmem ranges

 - Stop triggering request_key() notifications to userspace when
   NVDIMM-security is disabled / not present

 - Miscellaneous small fixups

* tag 'libnvdimm-fixes-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  libnvdimm/region: Enable MAP_SYNC for volatile regions
  libnvdimm: prevent nvdimm from requesting key when security is disabled
  libnvdimm/region: Initialize bad block for volatile namespaces
  libnvdimm/nfit_test: Fix acpi_handle redefinition
  libnvdimm/altmap: Track namespace boundaries in altmap
  libnvdimm: Fix endian conversion issues 
  libnvdimm/dax: Pick the right alignment default when creating dax devices
  powerpc/book3s64: Export has_transparent_hugepage() related functions.
2019-09-29 10:33:41 -07:00
Linus Torvalds
a2953204b5 powerpc fixes for 5.4 #2
An assortment of fixes that were either missed by me, or didn't arrive quite in
 time for the first v5.4 pull.
 
 Most notable is a fix for an issue with tlbie (broadcast TLB invalidation) on
 Power9, when using the Radix MMU. The tlbie can race with an mtpid (move to PID
 register, essentially MMU context switch) on another thread of the core, which
 can cause stores to continue to go to a page after it's unmapped.
 
 A fix in our KVM code to add a missing barrier, the lack of which has been
 observed to cause missed IPIs and subsequently stuck CPUs in the host.
 
 A change to the way we initialise PCR (Processor Compatibility Register) to make
 it forward compatible with future CPUs.
 
 On some older PowerVM systems our H_BLOCK_REMOVE support could oops, fix it to
 detect such systems and fallback to the old invalidation method.
 
 A fix for an oops seen on some machines when using KASAN on 32-bit.
 
 A handful of other minor fixes, and two new selftests.
 
 Thanks to:
   Alistair Popple, Aneesh Kumar K.V, Christophe Leroy, Gustavo Romero, Joel
   Stanley, Jordan Niethe, Laurent Dufour, Michael Roth, Oliver O'Halloran.
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Merge tag 'powerpc-5.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:
 "An assortment of fixes that were either missed by me, or didn't arrive
  quite in time for the first v5.4 pull.

   - Most notable is a fix for an issue with tlbie (broadcast TLB
     invalidation) on Power9, when using the Radix MMU. The tlbie can
     race with an mtpid (move to PID register, essentially MMU context
     switch) on another thread of the core, which can cause stores to
     continue to go to a page after it's unmapped.

   - A fix in our KVM code to add a missing barrier, the lack of which
     has been observed to cause missed IPIs and subsequently stuck CPUs
     in the host.

   - A change to the way we initialise PCR (Processor Compatibility
     Register) to make it forward compatible with future CPUs.

   - On some older PowerVM systems our H_BLOCK_REMOVE support could
     oops, fix it to detect such systems and fallback to the old
     invalidation method.

   - A fix for an oops seen on some machines when using KASAN on 32-bit.

   - A handful of other minor fixes, and two new selftests.

  Thanks to: Alistair Popple, Aneesh Kumar K.V, Christophe Leroy,
  Gustavo Romero, Joel Stanley, Jordan Niethe, Laurent Dufour, Michael
  Roth, Oliver O'Halloran"

* tag 'powerpc-5.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/eeh: Fix eeh eeh_debugfs_break_device() with SRIOV devices
  powerpc/nvdimm: use H_SCM_QUERY hcall on H_OVERLAP error
  powerpc/nvdimm: Use HCALL error as the return value
  selftests/powerpc: Add test case for tlbie vs mtpidr ordering issue
  powerpc/mm: Fixup tlbie vs mtpidr/mtlpidr ordering issue on POWER9
  powerpc/book3s64/radix: Rename CPU_FTR_P9_TLBIE_BUG feature flag
  powerpc/book3s64/mm: Don't do tlbie fixup for some hardware revisions
  powerpc/pseries: Call H_BLOCK_REMOVE when supported
  powerpc/pseries: Read TLB Block Invalidate Characteristics
  KVM: PPC: Book3S HV: use smp_mb() when setting/clearing host_ipi flag
  powerpc/mm: Fix an Oops in kasan_mmu_init()
  powerpc/mm: Add a helper to select PAGE_KERNEL_RO or PAGE_READONLY
  powerpc/64s: Set reserved PCR bits
  powerpc: Fix definition of PCR bits to work with old binutils
  powerpc/book3s64/radix: Remove WARN_ON in destroy_context()
  powerpc/tm: Add tm-poison test
2019-09-28 13:43:00 -07:00
Oliver O'Halloran
253c892193 powerpc/eeh: Fix eeh eeh_debugfs_break_device() with SRIOV devices
s/CONFIG_IOV/CONFIG_PCI_IOV/

Whoops.

Fixes: bd6461cc7b ("powerpc/eeh: Add a eeh_dev_break debugfs interface")
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
[mpe: Fixup the #endif comment as well]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190926122502.14826-1-oohall@gmail.com
2019-09-27 09:04:17 +10:00
Mark Rutland
b4ed71f557 mm: treewide: clarify pgtable_page_{ctor,dtor}() naming
The naming of pgtable_page_{ctor,dtor}() seems to have confused a few
people, and until recently arm64 used these erroneously/pointlessly for
other levels of page table.

To make it incredibly clear that these only apply to the PTE level, and to
align with the naming of pgtable_pmd_page_{ctor,dtor}(), let's rename them
to pgtable_pte_page_{ctor,dtor}().

These changes were generated with the following shell script:

----
git grep -lw 'pgtable_page_.tor' | while read FILE; do
    sed -i '{s/pgtable_page_ctor/pgtable_pte_page_ctor/}' $FILE;
    sed -i '{s/pgtable_page_dtor/pgtable_pte_page_dtor/}' $FILE;
done
----

... with the documentation re-flowed to remain under 80 columns, and
whitespace fixed up in macros to keep backslashes aligned.

There should be no functional change as a result of this patch.

Link: http://lkml.kernel.org/r/20190722141133.3116-1-mark.rutland@arm.com
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>	[m68k]
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-26 10:10:44 -07:00
Linus Torvalds
9c9fa97a8e Merge branch 'akpm' (patches from Andrew)
Merge updates from Andrew Morton:

 - a few hot fixes

 - ocfs2 updates

 - almost all of -mm (slab-generic, slab, slub, kmemleak, kasan,
   cleanups, debug, pagecache, memcg, gup, pagemap, memory-hotplug,
   sparsemem, vmalloc, initialization, z3fold, compaction, mempolicy,
   oom-kill, hugetlb, migration, thp, mmap, madvise, shmem, zswap,
   zsmalloc)

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (132 commits)
  mm/zsmalloc.c: fix a -Wunused-function warning
  zswap: do not map same object twice
  zswap: use movable memory if zpool support allocate movable memory
  zpool: add malloc_support_movable to zpool_driver
  shmem: fix obsolete comment in shmem_getpage_gfp()
  mm/madvise: reduce code duplication in error handling paths
  mm: mmap: increase sockets maximum memory size pgoff for 32bits
  mm/mmap.c: refine find_vma_prev() with rb_last()
  riscv: make mmap allocation top-down by default
  mips: use generic mmap top-down layout and brk randomization
  mips: replace arch specific way to determine 32bit task with generic version
  mips: adjust brk randomization offset to fit generic version
  mips: use STACK_TOP when computing mmap base address
  mips: properly account for stack randomization and stack guard gap
  arm: use generic mmap top-down layout and brk randomization
  arm: use STACK_TOP when computing mmap base address
  arm: properly account for stack randomization and stack guard gap
  arm64, mm: make randomization selected by generic topdown mmap layout
  arm64, mm: move generic mmap layout functions to mm
  arm64: consider stack randomization for mmap base only when necessary
  ...
2019-09-24 16:10:23 -07:00
Kefeng Wang
9ef258bad7 thp: update split_huge_page_pmd() comment
According to 78ddc53473 ("thp: rename split_huge_page_pmd() to
split_huge_pmd()"), update related comment.

Link: http://lkml.kernel.org/r/20190731033406.185285-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24 15:54:10 -07:00
Mike Rapoport
782de70c42 mm: consolidate pgtable_cache_init() and pgd_cache_init()
Both pgtable_cache_init() and pgd_cache_init() are used to initialize kmem
cache for page table allocations on several architectures that do not use
PAGE_SIZE tables for one or more levels of the page table hierarchy.

Most architectures do not implement these functions and use __weak default
NOP implementation of pgd_cache_init().  Since there is no such default
for pgtable_cache_init(), its empty stub is duplicated among most
architectures.

Rename the definitions of pgd_cache_init() to pgtable_cache_init() and
drop empty stubs of pgtable_cache_init().

Link: http://lkml.kernel.org/r/1566457046-22637-1-git-send-email-rppt@linux.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Will Deacon <will@kernel.org>		[arm64]
Acked-by: Thomas Gleixner <tglx@linutronix.de>	[x86]
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24 15:54:09 -07:00
Nicholas Piggin
13224794cb mm: remove quicklist page table caches
Patch series "mm: remove quicklist page table caches".

A while ago Nicholas proposed to remove quicklist page table caches [1].

I've rebased his patch on the curren upstream and switched ia64 and sh to
use generic versions of PTE allocation.

[1] https://lore.kernel.org/linux-mm/20190711030339.20892-1-npiggin@gmail.com

This patch (of 3):

Remove page table allocator "quicklists".  These have been around for a
long time, but have not got much traction in the last decade and are only
used on ia64 and sh architectures.

The numbers in the initial commit look interesting but probably don't
apply anymore.  If anybody wants to resurrect this it's in the git
history, but it's unhelpful to have this code and divergent allocator
behaviour for minor archs.

Also it might be better to instead make more general improvements to page
allocator if this is still so slow.

Link: http://lkml.kernel.org/r/1565250728-21721-2-git-send-email-rppt@linux.ibm.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24 15:54:09 -07:00
Matthew Wilcox (Oracle)
d8c6546b1a mm: introduce compound_nr()
Replace 1 << compound_order(page) with compound_nr(page).  Minor
improvements in readability.

Link: http://lkml.kernel.org/r/20190721104612.19120-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24 15:54:08 -07:00
Matthew Wilcox (Oracle)
94ad933810 mm: introduce page_shift()
Replace PAGE_SHIFT + compound_order(page) with the new page_shift()
function.  Minor improvements in readability.

[akpm@linux-foundation.org: fix build in tce_page_is_contained()]
  Link: http://lkml.kernel.org/r/201907241853.yNQTrJWd%25lkp@intel.com
Link: http://lkml.kernel.org/r/20190721104612.19120-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24 15:54:08 -07:00
Aneesh Kumar K.V
faa6d21153 powerpc/nvdimm: use H_SCM_QUERY hcall on H_OVERLAP error
Right now we force an unbind of SCM memory at drcindex on H_OVERLAP error.
This really slows down operations like kexec where we get the H_OVERLAP
error because we don't go through a full hypervisor re init.

H_OVERLAP error for a H_SCM_BIND_MEM hcall indicates that SCM memory at
drc index is already bound. Since we don't specify a logical memory
address for bind hcall, we can use the H_SCM_QUERY hcall to query
the already bound logical address.

Boot time difference with and without patch is:

[    5.583617] IOMMU table initialized, virtual merging enabled
[    5.603041] papr_scm ibm,persistent-memory:ibm,pmemory@44104001: Retrying bind after unbinding
[  301.514221] papr_scm ibm,persistent-memory:ibm,pmemory@44108001: Retrying bind after unbinding
[  340.057238] hv-24x7: read 1530 catalog entries, created 537 event attrs (0 failures), 275 descs

after fix

[    5.101572] IOMMU table initialized, virtual merging enabled
[    5.116984] papr_scm ibm,persistent-memory:ibm,pmemory@44104001: Querying SCM details
[    5.117223] papr_scm ibm,persistent-memory:ibm,pmemory@44108001: Querying SCM details
[    5.120530] hv-24x7: read 1530 catalog entries, created 537 event attrs (0 failures), 275 descs

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190903123452.28620-2-aneesh.kumar@linux.ibm.com
2019-09-25 08:32:59 +10:00
Aneesh Kumar K.V
4111cdef0e powerpc/nvdimm: Use HCALL error as the return value
This simplifies the error handling and also enable us to switch to
H_SCM_QUERY hcall in a later patch on H_OVERLAP error.

We also do some kernel print formatting fixup in this patch.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190903123452.28620-1-aneesh.kumar@linux.ibm.com
2019-09-25 08:32:59 +10:00
Linus Torvalds
0b36c9eed2 Merge branch 'work.mount3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more mount API conversions from Al Viro:
 "Assorted conversions of options parsing to new API.

  gfs2 is probably the most serious one here; the rest is trivial stuff.

  Other things in what used to be #work.mount are going to wait for the
  next cycle (and preferably go via git trees of the filesystems
  involved)"

* 'work.mount3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  gfs2: Convert gfs2 to fs_context
  vfs: Convert spufs to use the new mount API
  vfs: Convert hypfs to use the new mount API
  hypfs: Fix error number left in struct pointer member
  vfs: Convert functionfs to use the new mount API
  vfs: Convert bpf to use the new mount API
2019-09-24 12:33:34 -07:00
Aneesh Kumar K.V
cf387d9644 libnvdimm/altmap: Track namespace boundaries in altmap
With PFN_MODE_PMEM namespace, the memmap area is allocated from the device
area. Some architectures map the memmap area with large page size. On
architectures like ppc64, 16MB page for memap mapping can map 262144 pfns.
This maps a namespace size of 16G.

When populating memmap region with 16MB page from the device area,
make sure the allocated space is not used to map resources outside this
namespace. Such usage of device area will prevent a namespace destroy.

Add resource end pnf in altmap and use that to check if the memmap area
allocation can map pfn outside the namespace. On ppc64 in such case we fallback
to allocation from memory.

This fix kernel crash reported below:

[  132.034989] WARNING: CPU: 13 PID: 13719 at mm/memremap.c:133 devm_memremap_pages_release+0x2d8/0x2e0
[  133.464754] BUG: Unable to handle kernel data access at 0xc00c00010b204000
[  133.464760] Faulting instruction address: 0xc00000000007580c
[  133.464766] Oops: Kernel access of bad area, sig: 11 [#1]
[  133.464771] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
.....
[  133.464901] NIP [c00000000007580c] vmemmap_free+0x2ac/0x3d0
[  133.464906] LR [c0000000000757f8] vmemmap_free+0x298/0x3d0
[  133.464910] Call Trace:
[  133.464914] [c000007cbfd0f7b0] [c0000000000757f8] vmemmap_free+0x298/0x3d0 (unreliable)
[  133.464921] [c000007cbfd0f8d0] [c000000000370a44] section_deactivate+0x1a4/0x240
[  133.464928] [c000007cbfd0f980] [c000000000386270] __remove_pages+0x3a0/0x590
[  133.464935] [c000007cbfd0fa50] [c000000000074158] arch_remove_memory+0x88/0x160
[  133.464942] [c000007cbfd0fae0] [c0000000003be8c0] devm_memremap_pages_release+0x150/0x2e0
[  133.464949] [c000007cbfd0fb70] [c000000000738ea0] devm_action_release+0x30/0x50
[  133.464955] [c000007cbfd0fb90] [c00000000073a5a4] release_nodes+0x344/0x400
[  133.464961] [c000007cbfd0fc40] [c00000000073378c] device_release_driver_internal+0x15c/0x250
[  133.464968] [c000007cbfd0fc80] [c00000000072fd14] unbind_store+0x104/0x110
[  133.464973] [c000007cbfd0fcd0] [c00000000072ee24] drv_attr_store+0x44/0x70
[  133.464981] [c000007cbfd0fcf0] [c0000000004a32bc] sysfs_kf_write+0x6c/0xa0
[  133.464987] [c000007cbfd0fd10] [c0000000004a1dfc] kernfs_fop_write+0x17c/0x250
[  133.464993] [c000007cbfd0fd60] [c0000000003c348c] __vfs_write+0x3c/0x70
[  133.464999] [c000007cbfd0fd80] [c0000000003c75d0] vfs_write+0xd0/0x250

djbw: Aneesh notes that this crash can likely be triggered in any kernel that
supports 'papr_scm', so flagging that commit for -stable consideration.

Fixes: b5beae5e22 ("powerpc/pseries: Add driver for PAPR SCM regions")
Cc: <stable@vger.kernel.org>
Reported-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reviewed-by: Pankaj Gupta <pagupta@redhat.com>
Tested-by: Santosh Sivaraj <santosh@fossix.org>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Link: https://lore.kernel.org/r/20190910062826.10041-1-aneesh.kumar@linux.ibm.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2019-09-24 10:24:12 -07:00
Aneesh Kumar K.V
a6f197f889 powerpc/book3s64: Export has_transparent_hugepage() related functions.
In later patch, we want to use hash_transparent_hugepage() in a kernel module.
Export two related functions.

Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Link: https://lore.kernel.org/r/20190924042440.27946-1-aneesh.kumar@linux.ibm.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2019-09-24 10:22:29 -07:00
Aneesh Kumar K.V
047e6575ae powerpc/mm: Fixup tlbie vs mtpidr/mtlpidr ordering issue on POWER9
On POWER9, under some circumstances, a broadcast TLB invalidation will
fail to invalidate the ERAT cache on some threads when there are
parallel mtpidr/mtlpidr happening on other threads of the same core.
This can cause stores to continue to go to a page after it's unmapped.

The workaround is to force an ERAT flush using PID=0 or LPID=0 tlbie
flush. This additional TLB flush will cause the ERAT cache
invalidation. Since we are using PID=0 or LPID=0, we don't get
filtered out by the TLB snoop filtering logic.

We need to still follow this up with another tlbie to take care of
store vs tlbie ordering issue explained in commit:
a5d4b5891c ("powerpc/mm: Fixup tlbie vs store ordering issue on
POWER9"). The presence of ERAT cache implies we can still get new
stores and they may miss store queue marking flush.

Cc: stable@vger.kernel.org
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190924035254.24612-3-aneesh.kumar@linux.ibm.com
2019-09-24 20:58:55 +10:00
Aneesh Kumar K.V
09ce98cacd powerpc/book3s64/radix: Rename CPU_FTR_P9_TLBIE_BUG feature flag
Rename the #define to indicate this is related to store vs tlbie
ordering issue. In the next patch, we will be adding another feature
flag that is used to handles ERAT flush vs tlbie ordering issue.

Fixes: a5d4b5891c ("powerpc/mm: Fixup tlbie vs store ordering issue on POWER9")
Cc: stable@vger.kernel.org # v4.16+
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190924035254.24612-2-aneesh.kumar@linux.ibm.com
2019-09-24 20:58:47 +10:00
Aneesh Kumar K.V
677733e296 powerpc/book3s64/mm: Don't do tlbie fixup for some hardware revisions
The store ordering vs tlbie issue mentioned in commit
a5d4b5891c ("powerpc/mm: Fixup tlbie vs store ordering issue on
POWER9") is fixed for Nimbus 2.3 and Cumulus 1.3 revisions. We don't
need to apply the fixup if we are running on them

We can only do this on PowerNV. On pseries guest with KVM we still
don't support redoing the feature fixup after migration. So we should
be enabling all the workarounds needed, because whe can possibly
migrate between DD 2.3 and DD 2.2

Fixes: a5d4b5891c ("powerpc/mm: Fixup tlbie vs store ordering issue on POWER9")
Cc: stable@vger.kernel.org # v4.16+
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190924035254.24612-1-aneesh.kumar@linux.ibm.com
2019-09-24 20:57:50 +10:00
Laurent Dufour
59545ebe33 powerpc/pseries: Call H_BLOCK_REMOVE when supported
Depending on the hardware and the hypervisor, the hcall H_BLOCK_REMOVE
may not be able to process all the page sizes for a segment base page
size, as reported by the TLB Invalidate Characteristics.

For each pair of base segment page size and actual page size, this
characteristic tells us the size of the block the hcall supports.

In the case, the hcall is not supporting a pair of base segment page
size, actual page size, it is returning H_PARAM which leads to a panic
like this:

  kernel BUG at /home/srikar/work/linux.git/arch/powerpc/platforms/pseries/lpar.c:466!
  Oops: Exception in kernel mode, sig: 5 [#1]
  BE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
  Modules linked in:
  CPU: 28 PID: 583 Comm: modprobe Not tainted 5.2.0-master #5
  NIP: c0000000000be8dc LR: c0000000000be880 CTR: 0000000000000000
  REGS: c0000007e77fb130 TRAP: 0700  Not tainted (5.2.0-master)
  MSR: 8000000000029032 <SF,EE,ME,IR,DR,RI> CR: 42224824 XER: 20000000
  CFAR: c0000000000be8fc IRQMASK: 0
  GPR00: 0000000022224828 c0000007e77fb3c0 c000000001434d00 0000000000000005
  GPR04: 9000000004fa8c00 0000000000000000 0000000000000003 0000000000000001
  GPR08: c0000007e77fb450 0000000000000000 0000000000000001 ffffffffffffffff
  GPR12: c0000007e77fb450 c00000000edfcb80 0000cd7d3ea30000 c0000000016022b0
  GPR16: 00000000000000b0 0000cd7d3ea30000 0000000000000001 c080001f04f00105
  GPR20: 0000000000000003 0000000000000004 c000000fbeb05f58 c000000001602200
  GPR24: 0000000000000000 0000000000000004 8800000000000000 c000000000c5d148
  GPR28: c000000000000000 8000000000000000 a000000000000000 c0000007e77fb580
  NIP [c0000000000be8dc] .call_block_remove+0x12c/0x220
  LR [c0000000000be880] .call_block_remove+0xd0/0x220
  Call Trace:
    0xc000000fb8c00240 (unreliable)
    .pSeries_lpar_flush_hash_range+0x578/0x670
    .flush_hash_range+0x44/0x100
    .__flush_tlb_pending+0x3c/0xc0
    .zap_pte_range+0x7ec/0x830
    .unmap_page_range+0x3f4/0x540
    .unmap_vmas+0x94/0x120
    .exit_mmap+0xac/0x1f0
    .mmput+0x9c/0x1f0
    .do_exit+0x388/0xd60
    .do_group_exit+0x54/0x100
    .__se_sys_exit_group+0x14/0x20
    system_call+0x5c/0x70
  Instruction dump:
  39400001 38a00000 4800003c 60000000 60420000 7fa9e800 38e00000 419e0014
  7d29d278 7d290074 7929d182 69270001 <0b070000> 7d495378 394a0001 7fa93040

The call to H_BLOCK_REMOVE should only be made for the supported pair
of base segment page size, actual page size and using the correct
maximum block size.

Due to the required complexity in do_block_remove() and
call_block_remove(), and the fact that currently a block size of 8 is
returned by the hypervisor, we are only supporting 8 size block to the
H_BLOCK_REMOVE hcall.

In order to identify this limitation easily in the code, a local
define HBLKR_SUPPORTED_SIZE defining the currently supported block
size, and a dedicated checking helper is_supported_hlbkr() are
introduced.

For regular pages and hugetlb, the assumption is made that the page
size is equal to the base page size. For THP the page size is assumed
to be 16M.

Fixes: ba2dd8a26b ("powerpc/pseries/mm: call H_BLOCK_REMOVE")
Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190920130523.20441-3-ldufour@linux.ibm.com
2019-09-24 19:58:47 +10:00
Laurent Dufour
1211ee61b4 powerpc/pseries: Read TLB Block Invalidate Characteristics
The PAPR document specifies the TLB Block Invalidate Characteristics
which tells for each pair of segment base page size, actual page size,
the size of the block the hcall H_BLOCK_REMOVE supports.

These characteristics are loaded at boot time in a new table
hblkr_size. The table is separate from the mmu_psize_def because this
is specific to the pseries platform.

A new init function, pseries_lpar_read_hblkrm_characteristics() is
added to read the characteristics. It is called from
pSeries_setup_arch().

Fixes: ba2dd8a26b ("powerpc/pseries/mm: call H_BLOCK_REMOVE")
Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190920130523.20441-2-ldufour@linux.ibm.com
2019-09-24 19:58:42 +10:00
Michael Roth
3a83f677a6 KVM: PPC: Book3S HV: use smp_mb() when setting/clearing host_ipi flag
On a 2-socket Power9 system with 32 cores/128 threads (SMT4) and 1TB
of memory running the following guest configs:

  guest A:
    - 224GB of memory
    - 56 VCPUs (sockets=1,cores=28,threads=2), where:
      VCPUs 0-1 are pinned to CPUs 0-3,
      VCPUs 2-3 are pinned to CPUs 4-7,
      ...
      VCPUs 54-55 are pinned to CPUs 108-111

  guest B:
    - 4GB of memory
    - 4 VCPUs (sockets=1,cores=4,threads=1)

with the following workloads (with KSM and THP enabled in all):

  guest A:
    stress --cpu 40 --io 20 --vm 20 --vm-bytes 512M

  guest B:
    stress --cpu 4 --io 4 --vm 4 --vm-bytes 512M

  host:
    stress --cpu 4 --io 4 --vm 2 --vm-bytes 256M

the below soft-lockup traces were observed after an hour or so and
persisted until the host was reset (this was found to be reliably
reproducible for this configuration, for kernels 4.15, 4.18, 5.0,
and 5.3-rc5):

  [ 1253.183290] rcu: INFO: rcu_sched self-detected stall on CPU
  [ 1253.183319] rcu:     124-....: (5250 ticks this GP) idle=10a/1/0x4000000000000002 softirq=5408/5408 fqs=1941
  [ 1256.287426] watchdog: BUG: soft lockup - CPU#105 stuck for 23s! [CPU 52/KVM:19709]
  [ 1264.075773] watchdog: BUG: soft lockup - CPU#24 stuck for 23s! [worker:19913]
  [ 1264.079769] watchdog: BUG: soft lockup - CPU#31 stuck for 23s! [worker:20331]
  [ 1264.095770] watchdog: BUG: soft lockup - CPU#45 stuck for 23s! [worker:20338]
  [ 1264.131773] watchdog: BUG: soft lockup - CPU#64 stuck for 23s! [avocado:19525]
  [ 1280.408480] watchdog: BUG: soft lockup - CPU#124 stuck for 22s! [ksmd:791]
  [ 1316.198012] rcu: INFO: rcu_sched self-detected stall on CPU
  [ 1316.198032] rcu:     124-....: (21003 ticks this GP) idle=10a/1/0x4000000000000002 softirq=5408/5408 fqs=8243
  [ 1340.411024] watchdog: BUG: soft lockup - CPU#124 stuck for 22s! [ksmd:791]
  [ 1379.212609] rcu: INFO: rcu_sched self-detected stall on CPU
  [ 1379.212629] rcu:     124-....: (36756 ticks this GP) idle=10a/1/0x4000000000000002 softirq=5408/5408 fqs=14714
  [ 1404.413615] watchdog: BUG: soft lockup - CPU#124 stuck for 22s! [ksmd:791]
  [ 1442.227095] rcu: INFO: rcu_sched self-detected stall on CPU
  [ 1442.227115] rcu:     124-....: (52509 ticks this GP) idle=10a/1/0x4000000000000002 softirq=5408/5408 fqs=21403
  [ 1455.111787] INFO: task worker:19907 blocked for more than 120 seconds.
  [ 1455.111822]       Tainted: G             L    5.3.0-rc5-mdr-vanilla+ #1
  [ 1455.111833] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [ 1455.111884] INFO: task worker:19908 blocked for more than 120 seconds.
  [ 1455.111905]       Tainted: G             L    5.3.0-rc5-mdr-vanilla+ #1
  [ 1455.111925] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [ 1455.111966] INFO: task worker:20328 blocked for more than 120 seconds.
  [ 1455.111986]       Tainted: G             L    5.3.0-rc5-mdr-vanilla+ #1
  [ 1455.111998] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [ 1455.112048] INFO: task worker:20330 blocked for more than 120 seconds.
  [ 1455.112068]       Tainted: G             L    5.3.0-rc5-mdr-vanilla+ #1
  [ 1455.112097] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [ 1455.112138] INFO: task worker:20332 blocked for more than 120 seconds.
  [ 1455.112159]       Tainted: G             L    5.3.0-rc5-mdr-vanilla+ #1
  [ 1455.112179] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [ 1455.112210] INFO: task worker:20333 blocked for more than 120 seconds.
  [ 1455.112231]       Tainted: G             L    5.3.0-rc5-mdr-vanilla+ #1
  [ 1455.112242] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [ 1455.112282] INFO: task worker:20335 blocked for more than 120 seconds.
  [ 1455.112303]       Tainted: G             L    5.3.0-rc5-mdr-vanilla+ #1
  [ 1455.112332] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [ 1455.112372] INFO: task worker:20336 blocked for more than 120 seconds.
  [ 1455.112392]       Tainted: G             L    5.3.0-rc5-mdr-vanilla+ #1

CPUs 45, 24, and 124 are stuck on spin locks, likely held by
CPUs 105 and 31.

CPUs 105 and 31 are stuck in smp_call_function_many(), waiting on
target CPU 42. For instance:

  # CPU 105 registers (via xmon)
  R00 = c00000000020b20c   R16 = 00007d1bcd800000
  R01 = c00000363eaa7970   R17 = 0000000000000001
  R02 = c0000000019b3a00   R18 = 000000000000006b
  R03 = 000000000000002a   R19 = 00007d537d7aecf0
  R04 = 000000000000002a   R20 = 60000000000000e0
  R05 = 000000000000002a   R21 = 0801000000000080
  R06 = c0002073fb0caa08   R22 = 0000000000000d60
  R07 = c0000000019ddd78   R23 = 0000000000000001
  R08 = 000000000000002a   R24 = c00000000147a700
  R09 = 0000000000000001   R25 = c0002073fb0ca908
  R10 = c000008ffeb4e660   R26 = 0000000000000000
  R11 = c0002073fb0ca900   R27 = c0000000019e2464
  R12 = c000000000050790   R28 = c0000000000812b0
  R13 = c000207fff623e00   R29 = c0002073fb0ca808
  R14 = 00007d1bbee00000   R30 = c0002073fb0ca800
  R15 = 00007d1bcd600000   R31 = 0000000000000800
  pc  = c00000000020b260 smp_call_function_many+0x3d0/0x460
  cfar= c00000000020b270 smp_call_function_many+0x3e0/0x460
  lr  = c00000000020b20c smp_call_function_many+0x37c/0x460
  msr = 900000010288b033   cr  = 44024824
  ctr = c000000000050790   xer = 0000000000000000   trap =  100

CPU 42 is running normally, doing VCPU work:

  # CPU 42 stack trace (via xmon)
  [link register   ] c00800001be17188 kvmppc_book3s_radix_page_fault+0x90/0x2b0 [kvm_hv]
  [c000008ed3343820] c000008ed3343850 (unreliable)
  [c000008ed33438d0] c00800001be11b6c kvmppc_book3s_hv_page_fault+0x264/0xe30 [kvm_hv]
  [c000008ed33439d0] c00800001be0d7b4 kvmppc_vcpu_run_hv+0x8dc/0xb50 [kvm_hv]
  [c000008ed3343ae0] c00800001c10891c kvmppc_vcpu_run+0x34/0x48 [kvm]
  [c000008ed3343b00] c00800001c10475c kvm_arch_vcpu_ioctl_run+0x244/0x420 [kvm]
  [c000008ed3343b90] c00800001c0f5a78 kvm_vcpu_ioctl+0x470/0x7c8 [kvm]
  [c000008ed3343d00] c000000000475450 do_vfs_ioctl+0xe0/0xc70
  [c000008ed3343db0] c0000000004760e4 ksys_ioctl+0x104/0x120
  [c000008ed3343e00] c000000000476128 sys_ioctl+0x28/0x80
  [c000008ed3343e20] c00000000000b388 system_call+0x5c/0x70
  --- Exception: c00 (System Call) at 00007d545cfd7694
  SP (7d53ff7edf50) is in userspace

It was subsequently found that ipi_message[PPC_MSG_CALL_FUNCTION]
was set for CPU 42 by at least 1 of the CPUs waiting in
smp_call_function_many(), but somehow the corresponding
call_single_queue entries were never processed by CPU 42, causing the
callers to spin in csd_lock_wait() indefinitely.

Nick Piggin suggested something similar to the following sequence as
a possible explanation (interleaving of CALL_FUNCTION/RESCHEDULE
IPI messages seems to be most common, but any mix of CALL_FUNCTION and
!CALL_FUNCTION messages could trigger it):

    CPU
      X: smp_muxed_ipi_set_message():
      X:   smp_mb()
      X:   message[RESCHEDULE] = 1
      X: doorbell_global_ipi(42):
      X:   kvmppc_set_host_ipi(42, 1)
      X:   ppc_msgsnd_sync()/smp_mb()
      X:   ppc_msgsnd() -> 42
     42: doorbell_exception(): // from CPU X
     42:   ppc_msgsync()
    105: smp_muxed_ipi_set_message():
    105:   smb_mb()
         // STORE DEFERRED DUE TO RE-ORDERING
  --105:   message[CALL_FUNCTION] = 1
  | 105: doorbell_global_ipi(42):
  | 105:   kvmppc_set_host_ipi(42, 1)
  |  42:   kvmppc_set_host_ipi(42, 0)
  |  42: smp_ipi_demux_relaxed()
  |  42: // returns to executing guest
  |      // RE-ORDERED STORE COMPLETES
  ->105:   message[CALL_FUNCTION] = 1
    105:   ppc_msgsnd_sync()/smp_mb()
    105:   ppc_msgsnd() -> 42
     42: local_paca->kvm_hstate.host_ipi == 0 // IPI ignored
    105: // hangs waiting on 42 to process messages/call_single_queue

This can be prevented with an smp_mb() at the beginning of
kvmppc_set_host_ipi(), such that stores to message[<type>] (or other
state indicated by the host_ipi flag) are ordered vs. the store to
to host_ipi.

However, doing so might still allow for the following scenario (not
yet observed):

    CPU
      X: smp_muxed_ipi_set_message():
      X:   smp_mb()
      X:   message[RESCHEDULE] = 1
      X: doorbell_global_ipi(42):
      X:   kvmppc_set_host_ipi(42, 1)
      X:   ppc_msgsnd_sync()/smp_mb()
      X:   ppc_msgsnd() -> 42
     42: doorbell_exception(): // from CPU X
     42:   ppc_msgsync()
         // STORE DEFERRED DUE TO RE-ORDERING
  -- 42:   kvmppc_set_host_ipi(42, 0)
  |  42: smp_ipi_demux_relaxed()
  | 105: smp_muxed_ipi_set_message():
  | 105:   smb_mb()
  | 105:   message[CALL_FUNCTION] = 1
  | 105: doorbell_global_ipi(42):
  | 105:   kvmppc_set_host_ipi(42, 1)
  |      // RE-ORDERED STORE COMPLETES
  -> 42:   kvmppc_set_host_ipi(42, 0)
     42: // returns to executing guest
    105:   ppc_msgsnd_sync()/smp_mb()
    105:   ppc_msgsnd() -> 42
     42: local_paca->kvm_hstate.host_ipi == 0 // IPI ignored
    105: // hangs waiting on 42 to process messages/call_single_queue

Fixing this scenario would require an smp_mb() *after* clearing
host_ipi flag in kvmppc_set_host_ipi() to order the store vs.
subsequent processing of IPI messages.

To handle both cases, this patch splits kvmppc_set_host_ipi() into
separate set/clear functions, where we execute smp_mb() prior to
setting host_ipi flag, and after clearing host_ipi flag. These
functions pair with each other to synchronize the sender and receiver
sides.

With that change in place the above workload ran for 20 hours without
triggering any lock-ups.

Fixes: 755563bc79 ("powerpc/powernv: Fixes for hypervisor doorbell handling") # v4.0
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Acked-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190911223155.16045-1-mdroth@linux.vnet.ibm.com
2019-09-24 12:46:26 +10:00
Linus Torvalds
299d14d4c3 pci-v5.4-changes
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Merge tag 'pci-v5.4-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

Pull PCI updates from Bjorn Helgaas:
 "Enumeration:

   - Consolidate _HPP/_HPX stuff in pci-acpi.c and simplify it
     (Krzysztof Wilczynski)

   - Fix incorrect PCIe device types and remove dev->has_secondary_link
     to simplify code that deals with upstream/downstream ports (Mika
     Westerberg)

   - After suspend, restore Resizable BAR size bits correctly for 1MB
     BARs (Sumit Saxena)

   - Enable PCI_MSI_IRQ_DOMAIN support for RISC-V (Wesley Terpstra)

  Virtualization:

   - Add ACS quirks for iProc PAXB (Abhinav Ratna), Amazon Annapurna
     Labs (Ali Saidi)

   - Move sysfs SR-IOV functions to iov.c (Kelsey Skunberg)

   - Remove group write permissions from sysfs sriov_numvfs,
     sriov_drivers_autoprobe (Kelsey Skunberg)

  Hotplug:

   - Simplify pciehp indicator control (Denis Efremov)

  Peer-to-peer DMA:

   - Allow P2P DMA between root ports for whitelisted bridges (Logan
     Gunthorpe)

   - Whitelist some Intel host bridges for P2P DMA (Logan Gunthorpe)

   - DMA map P2P DMA requests that traverse host bridge (Logan
     Gunthorpe)

  Amazon Annapurna Labs host bridge driver:

   - Add DT binding and controller driver (Jonathan Chocron)

  Hyper-V host bridge driver:

   - Fix hv_pci_dev->pci_slot use-after-free (Dexuan Cui)

   - Fix PCI domain number collisions (Haiyang Zhang)

   - Use instance ID bytes 4 & 5 as PCI domain numbers (Haiyang Zhang)

   - Fix build errors on non-SYSFS config (Randy Dunlap)

  i.MX6 host bridge driver:

   - Limit DBI register length (Stefan Agner)

  Intel VMD host bridge driver:

   - Fix config addressing issues (Jon Derrick)

  Layerscape host bridge driver:

   - Add bar_fixed_64bit property to endpoint driver (Xiaowei Bao)

   - Add CONFIG_PCI_LAYERSCAPE_EP to build EP/RC drivers separately
     (Xiaowei Bao)

  Mediatek host bridge driver:

   - Add MT7629 controller support (Jianjun Wang)

  Mobiveil host bridge driver:

   - Fix CPU base address setup (Hou Zhiqiang)

   - Make "num-lanes" property optional (Hou Zhiqiang)

  Tegra host bridge driver:

   - Fix OF node reference leak (Nishka Dasgupta)

   - Disable MSI for root ports to work around design problem (Vidya
     Sagar)

   - Add Tegra194 DT binding and controller support (Vidya Sagar)

   - Add support for sideband pins and slot regulators (Vidya Sagar)

   - Add PIPE2UPHY support (Vidya Sagar)

  Misc:

   - Remove unused pci_block_cfg_access() et al (Kelsey Skunberg)

   - Unexport pci_bus_get(), etc (Kelsey Skunberg)

   - Hide PM, VC, link speed, ATS, ECRC, PTM constants and interfaces in
     the PCI core (Kelsey Skunberg)

   - Clean up sysfs DEVICE_ATTR() usage (Kelsey Skunberg)

   - Mark expected switch fall-through (Gustavo A. R. Silva)

   - Propagate errors for optional regulators and PHYs (Thierry Reding)

   - Fix kernel command line resource_alignment parameter issues (Logan
     Gunthorpe)"

* tag 'pci-v5.4-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (112 commits)
  PCI: Add pci_irq_vector() and other stubs when !CONFIG_PCI
  arm64: tegra: Add PCIe slot supply information in p2972-0000 platform
  arm64: tegra: Add configuration for PCIe C5 sideband signals
  PCI: tegra: Add support to enable slot regulators
  PCI: tegra: Add support to configure sideband pins
  PCI: vmd: Fix shadow offsets to reflect spec changes
  PCI: vmd: Fix config addressing when using bus offsets
  PCI: dwc: Add validation that PCIe core is set to correct mode
  PCI: dwc: al: Add Amazon Annapurna Labs PCIe controller driver
  dt-bindings: PCI: Add Amazon's Annapurna Labs PCIe host bridge binding
  PCI: Add quirk to disable MSI-X support for Amazon's Annapurna Labs Root Port
  PCI/VPD: Prevent VPD access for Amazon's Annapurna Labs Root Port
  PCI: Add ACS quirk for Amazon Annapurna Labs root ports
  PCI: Add Amazon's Annapurna Labs vendor ID
  MAINTAINERS: Add PCI native host/endpoint controllers designated reviewer
  PCI: hv: Use bytes 4 and 5 from instance ID as the PCI domain numbers
  dt-bindings: PCI: tegra: Add PCIe slot supplies regulator entries
  dt-bindings: PCI: tegra: Add sideband pins configuration entries
  PCI: tegra: Add Tegra194 PCIe support
  PCI: Get rid of dev->has_secondary_link flag
  ...
2019-09-23 19:16:01 -07:00
Linus Torvalds
84da111de0 hmm related patches for 5.4
This is more cleanup and consolidation of the hmm APIs and the very
 strongly related mmu_notifier interfaces. Many places across the tree
 using these interfaces are touched in the process. Beyond that a cleanup
 to the page walker API and a few memremap related changes round out the
 series:
 
 - General improvement of hmm_range_fault() and related APIs, more
   documentation, bug fixes from testing, API simplification &
   consolidation, and unused API removal
 
 - Simplify the hmm related kconfigs to HMM_MIRROR and DEVICE_PRIVATE, and
   make them internal kconfig selects
 
 - Hoist a lot of code related to mmu notifier attachment out of drivers by
   using a refcount get/put attachment idiom and remove the convoluted
   mmu_notifier_unregister_no_release() and related APIs.
 
 - General API improvement for the migrate_vma API and revision of its only
   user in nouveau
 
 - Annotate mmu_notifiers with lockdep and sleeping region debugging
 
 Two series unrelated to HMM or mmu_notifiers came along due to
 dependencies:
 
 - Allow pagemap's memremap_pages family of APIs to work without providing
   a struct device
 
 - Make walk_page_range() and related use a constant structure for function
   pointers
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Merge tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma

Pull hmm updates from Jason Gunthorpe:
 "This is more cleanup and consolidation of the hmm APIs and the very
  strongly related mmu_notifier interfaces. Many places across the tree
  using these interfaces are touched in the process. Beyond that a
  cleanup to the page walker API and a few memremap related changes
  round out the series:

   - General improvement of hmm_range_fault() and related APIs, more
     documentation, bug fixes from testing, API simplification &
     consolidation, and unused API removal

   - Simplify the hmm related kconfigs to HMM_MIRROR and DEVICE_PRIVATE,
     and make them internal kconfig selects

   - Hoist a lot of code related to mmu notifier attachment out of
     drivers by using a refcount get/put attachment idiom and remove the
     convoluted mmu_notifier_unregister_no_release() and related APIs.

   - General API improvement for the migrate_vma API and revision of its
     only user in nouveau

   - Annotate mmu_notifiers with lockdep and sleeping region debugging

  Two series unrelated to HMM or mmu_notifiers came along due to
  dependencies:

   - Allow pagemap's memremap_pages family of APIs to work without
     providing a struct device

   - Make walk_page_range() and related use a constant structure for
     function pointers"

* tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: (75 commits)
  libnvdimm: Enable unit test infrastructure compile checks
  mm, notifier: Catch sleeping/blocking for !blockable
  kernel.h: Add non_block_start/end()
  drm/radeon: guard against calling an unpaired radeon_mn_unregister()
  csky: add missing brackets in a macro for tlb.h
  pagewalk: use lockdep_assert_held for locking validation
  pagewalk: separate function pointers from iterator data
  mm: split out a new pagewalk.h header from mm.h
  mm/mmu_notifiers: annotate with might_sleep()
  mm/mmu_notifiers: prime lockdep
  mm/mmu_notifiers: add a lockdep map for invalidate_range_start/end
  mm/mmu_notifiers: remove the __mmu_notifier_invalidate_range_start/end exports
  mm/hmm: hmm_range_fault() infinite loop
  mm/hmm: hmm_range_fault() NULL pointer bug
  mm/hmm: fix hmm_range_fault()'s handling of swapped out pages
  mm/mmu_notifiers: remove unregister_no_release
  RDMA/odp: remove ib_ucontext from ib_umem
  RDMA/odp: use mmu_notifier_get/put for 'struct ib_ucontext_per_mm'
  RDMA/mlx5: Use odp instead of mr->umem in pagefault_mr
  RDMA/mlx5: Use ib_umem_start instead of umem.address
  ...
2019-09-21 10:07:42 -07:00
Christophe Leroy
cbd18991e2 powerpc/mm: Fix an Oops in kasan_mmu_init()
Uncompressing Kernel Image ... OK
   Loading Device Tree to 01ff7000, end 01fff74f ... OK
[    0.000000] printk: bootconsole [udbg0] enabled
[    0.000000] BUG: Unable to handle kernel data access at 0xf818c000
[    0.000000] Faulting instruction address: 0xc0013c7c
[    0.000000] Thread overran stack, or stack corrupted
[    0.000000] Oops: Kernel access of bad area, sig: 11 [#1]
[    0.000000] BE PAGE_SIZE=16K PREEMPT
[    0.000000] Modules linked in:
[    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 5.3.0-rc4-s3k-dev-00743-g5abe4a3e8fd3-dirty #2080
[    0.000000] NIP:  c0013c7c LR: c0013310 CTR: 00000000
[    0.000000] REGS: c0c5ff38 TRAP: 0300   Not tainted  (5.3.0-rc4-s3k-dev-00743-g5abe4a3e8fd3-dirty)
[    0.000000] MSR:  00001032 <ME,IR,DR,RI>  CR: 99033955  XER: 80002100
[    0.000000] DAR: f818c000 DSISR: 82000000
[    0.000000] GPR00: c0013310 c0c5fff0 c0ad6ac0 c0c600c0 f818c031 82000000 00000000 ffffffff
[    0.000000] GPR08: 00000000 f1f1f1f1 c0013c2c c0013304 99033955 00400008 00000000 07ff9598
[    0.000000] GPR16: 00000000 07ffb94c 00000000 00000000 00000000 00000000 00000000 f818cfb2
[    0.000000] GPR24: 00000000 00000000 00001000 ffffffff 00000000 c07dbf80 00000000 f818c000
[    0.000000] NIP [c0013c7c] do_page_fault+0x50/0x904
[    0.000000] LR [c0013310] handle_page_fault+0xc/0x38
[    0.000000] Call Trace:
[    0.000000] Instruction dump:
[    0.000000] be010080 91410014 553fe8fe 3d40c001 3d20f1f1 7d800026 394a3c2c 3fffe000
[    0.000000] 6129f1f1 900100c4 9181007c 91410018 <913f0000> 3d2001f4 6129f4f4 913f0004

Don't map the early shadow page read-only yet when creating the new
page tables for the real shadow memory, otherwise the memblock
allocations that immediately follows to create the real shadow pages
that are about to replace the early shadow page trigger a page fault
if they fall into the region being worked on at the moment.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Fixes: 2edb16efc8 ("powerpc/32: Add KASAN support")
Cc: stable@vger.kernel.org
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/fe86886fb8db44360417cee0dc515ad47ca6ef72.1566382750.git.christophe.leroy@c-s.fr
2019-09-21 08:36:53 +10:00
Christophe Leroy
4c0f5d1eb4 powerpc/mm: Add a helper to select PAGE_KERNEL_RO or PAGE_READONLY
In a couple of places there is a need to select whether read-only
protection of shadow pages is performed with PAGE_KERNEL_RO or with
PAGE_READONLY.

Add a helper to avoid duplicating the choice.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: stable@vger.kernel.org
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/9f33f44b9cd741c4a02b3dce7b8ef9438fe2cd2a.1566382750.git.christophe.leroy@c-s.fr
2019-09-21 08:36:53 +10:00
Jordan Niethe
13c7bb3c57 powerpc/64s: Set reserved PCR bits
Currently the reserved bits of the Processor Compatibility
Register (PCR) are cleared as per the Programming Note in Section
1.3.3 of version 3.0B of the Power ISA. This causes all new
architecture features to be made available when running on newer
processors with new architecture features added to the PCR as bits
must be set to disable a given feature.

For example to disable new features added as part of Version 2.07 of
the ISA the corresponding bit in the PCR needs to be set.

As new processor features generally require explicit kernel support
they should be disabled until such support is implemented. Therefore
kernels should set all unknown/reserved bits in the PCR such that any
new architecture features which the kernel does not currently know
about get disabled.

An update is planned to the ISA to clarify that the PCR is an
exception to the Programming Note on reserved bits in Section 1.3.3.

Signed-off-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Tested-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190917004605.22471-2-alistair@popple.id.au
2019-09-21 08:36:53 +10:00