Commit Graph

134 Commits

Author SHA1 Message Date
Maxim Levitsky
772b81bb2f SVM: nSVM: setup nested msr permission bitmap on nested state load
This code was missing and was forcing the L2 run with L1's msr
permission bitmap

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20200827162720.278690-3-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-09-12 12:20:53 -04:00
Maxim Levitsky
9883764ad0 SVM: nSVM: correctly restore GIF on vmexit from nesting after migration
Currently code in svm_set_nested_state copies the current vmcb control
area to L1 control area (hsave->control), under assumption that
it mostly reflects the defaults that kvm choose, and later qemu
overrides  these defaults with L2 state using standard KVM interfaces,
like KVM_SET_REGS.

However nested GIF (which is AMD specific thing) is by default is true,
and it is copied to hsave area as such.

This alone is not a big deal since on VMexit, GIF is always set to false,
regardless of what it was on VM entry.  However in nested_svm_vmexit we
were first were setting GIF to false, but then we overwrite the control
fields with value from the hsave area.  (including the nested GIF field
itself if GIF virtualization is enabled).

Now on normal vm entry this is not a problem, since GIF is usually false
prior to normal vm entry, and this is the value that copied to hsave,
and then restored, but this is not always the case when the nested state
is loaded as explained above.

To fix this issue, move svm_set_gif after we restore the L1 control
state in nested_svm_vmexit, so that even with wrong GIF in the
saved L1 control area, we still clear GIF as the spec says.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20200827162720.278690-2-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-09-12 12:19:06 -04:00
Wanpeng Li
e42c68281b KVM: SVM: avoid emulation with stale next_rip
svm->next_rip is reset in svm_vcpu_run() only after calling
svm_exit_handlers_fastpath(), which will cause SVM's
skip_emulated_instruction() to write a stale RIP.

We can move svm_exit_handlers_fastpath towards the end of
svm_vcpu_run().  To align VMX with SVM, keep svm_complete_interrupts()
close as well.

Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Paul K. <kronenpj@kronenpj.dyndns.org>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
[Also move vmcb_mark_all_clean before any possible write to the VMCB.
 - Paolo]
2020-09-12 02:19:23 -04:00
David Rientjes
7be74942f1 KVM: SVM: Periodically schedule when unregistering regions on destroy
There may be many encrypted regions that need to be unregistered when a
SEV VM is destroyed.  This can lead to soft lockups.  For example, on a
host running 4.15:

watchdog: BUG: soft lockup - CPU#206 stuck for 11s! [t_virtual_machi:194348]
CPU: 206 PID: 194348 Comm: t_virtual_machi
RIP: 0010:free_unref_page_list+0x105/0x170
...
Call Trace:
 [<0>] release_pages+0x159/0x3d0
 [<0>] sev_unpin_memory+0x2c/0x50 [kvm_amd]
 [<0>] __unregister_enc_region_locked+0x2f/0x70 [kvm_amd]
 [<0>] svm_vm_destroy+0xa9/0x200 [kvm_amd]
 [<0>] kvm_arch_destroy_vm+0x47/0x200
 [<0>] kvm_put_kvm+0x1a8/0x2f0
 [<0>] kvm_vm_release+0x25/0x30
 [<0>] do_exit+0x335/0xc10
 [<0>] do_group_exit+0x3f/0xa0
 [<0>] get_signal+0x1bc/0x670
 [<0>] do_signal+0x31/0x130

Although the CLFLUSH is no longer issued on every encrypted region to be
unregistered, there are no other changes that can prevent soft lockups for
very large SEV VMs in the latest kernel.

Periodically schedule if necessary.  This still holds kvm->lock across the
resched, but since this only happens when the VM is destroyed this is
assumed to be acceptable.

Signed-off-by: David Rientjes <rientjes@google.com>
Message-Id: <alpine.DEB.2.23.453.2008251255240.2987727@chino.kir.corp.google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-09-11 13:24:15 -04:00
Linus Torvalds
921d2597ab s390: implement diag318
x86:
 * Report last CPU for debugging
 * Emulate smaller MAXPHYADDR in the guest than in the host
 * .noinstr and tracing fixes from Thomas
 * nested SVM page table switching optimization and fixes
 
 Generic:
 * Unify shadow MMU cache data structures across architectures
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Paolo Bonzini:
 "s390:
   - implement diag318

  x86:
   - Report last CPU for debugging
   - Emulate smaller MAXPHYADDR in the guest than in the host
   - .noinstr and tracing fixes from Thomas
   - nested SVM page table switching optimization and fixes

  Generic:
   - Unify shadow MMU cache data structures across architectures"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (127 commits)
  KVM: SVM: Fix sev_pin_memory() error handling
  KVM: LAPIC: Set the TDCR settable bits
  KVM: x86: Specify max TDP level via kvm_configure_mmu()
  KVM: x86/mmu: Rename max_page_level to max_huge_page_level
  KVM: x86: Dynamically calculate TDP level from max level and MAXPHYADDR
  KVM: VXM: Remove temporary WARN on expected vs. actual EPTP level mismatch
  KVM: x86: Pull the PGD's level from the MMU instead of recalculating it
  KVM: VMX: Make vmx_load_mmu_pgd() static
  KVM: x86/mmu: Add separate helper for shadow NPT root page role calc
  KVM: VMX: Drop a duplicate declaration of construct_eptp()
  KVM: nSVM: Correctly set the shadow NPT root level in its MMU role
  KVM: Using macros instead of magic values
  MIPS: KVM: Fix build error caused by 'kvm_run' cleanup
  KVM: nSVM: remove nonsensical EXITINFO1 adjustment on nested NPF
  KVM: x86: Add a capability for GUEST_MAXPHYADDR < HOST_MAXPHYADDR support
  KVM: VMX: optimize #PF injection when MAXPHYADDR does not match
  KVM: VMX: Add guest physical address check in EPT violation and misconfig
  KVM: VMX: introduce vmx_need_pf_intercept
  KVM: x86: update exception bitmap on CPUID changes
  KVM: x86: rename update_bp_intercept to update_exception_bitmap
  ...
2020-08-06 12:59:31 -07:00
Dan Carpenter
ff2bd9ff11 KVM: SVM: Fix sev_pin_memory() error handling
The sev_pin_memory() function was modified to return error pointers
instead of NULL but there are two problems.  The first problem is that
if "npages" is zero then it still returns NULL.  Secondly, several of
the callers were not updated to check for error pointers instead of
NULL.

Either one of these issues will lead to an Oops.

Fixes: a8d908b587 ("KVM: x86: report sev_pin_memory errors with PTR_ERR")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Message-Id: <20200714142351.GA315374@mwanda>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-08-02 05:23:06 -04:00
Wanpeng Li
830f01b089 KVM: SVM: Fix disable pause loop exit/pause filtering capability on SVM
'Commit 8566ac8b8e ("KVM: SVM: Implement pause loop exit logic in SVM")'
drops disable pause loop exit/pause filtering capability completely, I
guess it is a merge fault by Radim since disable vmexits capabilities and
pause loop exit for SVM patchsets are merged at the same time. This patch
reintroduces the disable pause loop exit/pause filtering capability support.

Reported-by: Haiwei Li <lihaiwei@tencent.com>
Tested-by: Haiwei Li <lihaiwei@tencent.com>
Fixes: 8566ac8b ("KVM: SVM: Implement pause loop exit logic in SVM")
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Message-Id: <1596165141-28874-3-git-send-email-wanpengli@tencent.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-31 03:20:32 -04:00
Sean Christopherson
83013059bd KVM: x86: Specify max TDP level via kvm_configure_mmu()
Capture the max TDP level during kvm_configure_mmu() instead of using a
kvm_x86_ops hook to do it at every vCPU creation.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200716034122.5998-10-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-30 18:18:08 -04:00
Sean Christopherson
d468d94b7b KVM: x86: Dynamically calculate TDP level from max level and MAXPHYADDR
Calculate the desired TDP level on the fly using the max TDP level and
MAXPHYADDR instead of doing the same when CPUID is updated.  This avoids
the hidden dependency on cpuid_maxphyaddr() in vmx_get_tdp_level() and
also standardizes the "use 5-level paging iff MAXPHYADDR > 48" behavior
across x86.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200716034122.5998-8-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-30 18:17:16 -04:00
Sean Christopherson
2a40b9001e KVM: x86: Pull the PGD's level from the MMU instead of recalculating it
Use the shadow_root_level from the current MMU as the root level for the
PGD, i.e. for VMX's EPTP.  This eliminates the weird dependency between
VMX and the MMU where both must independently calculate the same root
level for things to work correctly.  Temporarily keep VMX's calculation
of the level and use it to WARN if the incoming level diverges.

Opportunistically refactor kvm_mmu_load_pgd() to avoid indentation hell,
and rename a 'cr3' param in the load_mmu_pgd prototype that managed to
survive the cr3 purge.

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200716034122.5998-6-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-30 18:16:47 -04:00
Sean Christopherson
096586fda5 KVM: nSVM: Correctly set the shadow NPT root level in its MMU role
Move the initialization of shadow NPT MMU's shadow_root_level into
kvm_init_shadow_npt_mmu() and explicitly set the level in the shadow NPT
MMU's role to be the TDP level.  This ensures the role and MMU levels
are synchronized and also initialized before __kvm_mmu_new_pgd(), which
consumes the level when attempting a fast PGD switch.

Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Fixes: 9fa72119b2 ("kvm: x86: Introduce kvm_mmu_calc_root_page_role()")
Fixes: a506fdd223 ("KVM: nSVM: implement nested_svm_load_cr3() and use it for host->guest switch")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200716034122.5998-2-sean.j.christopherson@intel.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-30 18:13:23 -04:00
Paolo Bonzini
e8af9e9f45 KVM: nSVM: remove nonsensical EXITINFO1 adjustment on nested NPF
The "if" that drops the present bit from the page structure fauls makes no sense.
It was added by yours truly in order to be bug-compatible with pre-existing code
and in order to make the tests pass; however, the tests are wrong.  The behavior
after this patch matches bare metal.

Reported-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-10 17:01:54 -04:00
Mohammed Gamal
3edd68399d KVM: x86: Add a capability for GUEST_MAXPHYADDR < HOST_MAXPHYADDR support
This patch adds a new capability KVM_CAP_SMALLER_MAXPHYADDR which
allows userspace to query if the underlying architecture would
support GUEST_MAXPHYADDR < HOST_MAXPHYADDR and hence act accordingly
(e.g. qemu can decide if it should warn for -cpu ..,phys-bits=X)

The complications in this patch are due to unexpected (but documented)
behaviour we see with NPF vmexit handling in AMD processor.  If
SVM is modified to add guest physical address checks in the NPF
and guest #PF paths, we see the followning error multiple times in
the 'access' test in kvm-unit-tests:

            test pte.p pte.36 pde.p: FAIL: pte 2000021 expected 2000001
            Dump mapping: address: 0x123400000000
            ------L4: 24c3027
            ------L3: 24c4027
            ------L2: 24c5021
            ------L1: 1002000021

This is because the PTE's accessed bit is set by the CPU hardware before
the NPF vmexit. This is handled completely by hardware and cannot be fixed
in software.

Therefore, availability of the new capability depends on a boolean variable
allow_smaller_maxphyaddr which is set individually by VMX and SVM init
routines. On VMX it's always set to true, on SVM it's only set to true
when NPT is not enabled.

CC: Tom Lendacky <thomas.lendacky@amd.com>
CC: Babu Moger <babu.moger@amd.com>
Signed-off-by: Mohammed Gamal <mgamal@redhat.com>
Message-Id: <20200710154811.418214-10-mgamal@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-10 17:01:53 -04:00
Paolo Bonzini
6986982fef KVM: x86: rename update_bp_intercept to update_exception_bitmap
We would like to introduce a callback to update the #PF intercept
when CPUID changes.  Just reuse update_bp_intercept since VMX is
already using update_exception_bitmap instead of a bespoke function.

While at it, remove an unnecessary assignment in the SVM version,
which is already done in the caller (kvm_arch_vcpu_ioctl_set_guest_debug)
and has nothing to do with the exception bitmap.

Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-10 13:20:18 -04:00
Vitaly Kuznetsov
d82aaef9c8 KVM: nSVM: use nested_svm_load_cr3() on guest->host switch
Make nSVM code resemble nVMX where nested_vmx_load_cr3() is used on
both guest->host and host->guest transitions. Also, we can now
eliminate unconditional kvm_mmu_reset_context() and speed things up.

Note, nVMX has two different paths: load_vmcs12_host_state() and
nested_vmx_restore_host_state() and the later is used to restore from
'partial' switch to L2, it always uses kvm_mmu_reset_context().
nSVM doesn't have this yet. Also, nested_svm_vmexit()'s return value
is almost always ignored nowadays.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20200710141157.1640173-9-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-10 12:59:39 -04:00
Vitaly Kuznetsov
a506fdd223 KVM: nSVM: implement nested_svm_load_cr3() and use it for host->guest switch
Undesired triple fault gets injected to L1 guest on SVM when L2 is
launched with certain CR3 values. #TF is raised by mmu_check_root()
check in fast_pgd_switch() and the root cause is that when
kvm_set_cr3() is called from nested_prepare_vmcb_save() with NPT
enabled CR3 points to a nGPA so we can't check it with
kvm_is_visible_gfn().

Using generic kvm_set_cr3() when switching to nested guest is not
a great idea as we'll have to distinguish between 'real' CR3s and
'nested' CR3s to e.g. not call kvm_mmu_new_pgd() with nGPA. Following
nVMX implement nested-specific nested_svm_load_cr3() doing the job.

To support the change, nested_svm_load_cr3() needs to be re-ordered
with nested_svm_init_mmu_context().

Note: the current implementation is sub-optimal as we always do TLB
flush/MMU sync but this is still an improvement as we at least stop doing
kvm_mmu_reset_context().

Fixes: 7c390d350f ("kvm: x86: Add fast CR3 switch code path")
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20200710141157.1640173-8-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-10 12:57:37 -04:00
Vitaly Kuznetsov
bf7dea4253 KVM: nSVM: move kvm_set_cr3() after nested_svm_uninit_mmu_context()
kvm_mmu_new_pgd() refers to arch.mmu and at this point it still references
arch.guest_mmu while arch.root_mmu is expected.

Note, the change is effectively a nop: when !npt_enabled,
nested_svm_uninit_mmu_context() does nothing (as we don't do
nested_svm_init_mmu_context()) and with npt_enabled we don't
do kvm_set_cr3().  However, it will matter when we move the
call to kvm_mmu_new_pgd into nested_svm_load_cr3().

No functional change intended.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20200710141157.1640173-7-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-10 12:56:30 -04:00
Vitaly Kuznetsov
62156f6cd1 KVM: nSVM: introduce nested_svm_load_cr3()/nested_npt_enabled()
As a preparatory change for implementing nSVM-specific PGD switch
(following nVMX' nested_vmx_load_cr3()), introduce nested_svm_load_cr3()
instead of relying on kvm_set_cr3().

No functional change intended.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20200710141157.1640173-6-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-10 12:55:36 -04:00
Vitaly Kuznetsov
59cd9bc5b0 KVM: nSVM: prepare to handle errors from enter_svm_guest_mode()
Some operations in enter_svm_guest_mode() may fail, e.g. currently
we suppress kvm_set_cr3() return value. Prepare the code to proparate
errors.

No functional change intended.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20200710141157.1640173-5-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-10 12:55:13 -04:00
Vitaly Kuznetsov
ebdb3dba7b KVM: nSVM: reset nested_run_pending upon nested_svm_vmrun_msrpm() failure
WARN_ON_ONCE(svm->nested.nested_run_pending) in nested_svm_vmexit()
will fire if nested_run_pending remains '1' but it doesn't really
need to, we are already failing and not going to run nested guest.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20200710141157.1640173-4-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-10 12:54:25 -04:00
Vitaly Kuznetsov
0f04a2ac4f KVM: nSVM: split kvm_init_shadow_npt_mmu() from kvm_init_shadow_mmu()
As a preparatory change for moving kvm_mmu_new_pgd() from
nested_prepare_vmcb_save() to nested_svm_init_mmu_context() split
kvm_init_shadow_npt_mmu() from kvm_init_shadow_mmu(). This also makes
the code look more like nVMX (kvm_init_shadow_ept_mmu()).

No functional change intended.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20200710141157.1640173-2-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-10 12:53:27 -04:00
Vitaly Kuznetsov
d574c539c3 KVM: x86: move MSR_IA32_PERF_CAPABILITIES emulation to common x86 code
state_test/smm_test selftests are failing on AMD with:
"Unexpected result from KVM_GET_MSRS, r: 51 (failed MSR was 0x345)"

MSR_IA32_PERF_CAPABILITIES is an emulated MSR on Intel but it is not
known to AMD code, we can move the emulation to common x86 code. For
AMD, we basically just allow the host to read and write zero to the MSR.

Fixes: 27461da310 ("KVM: x86/pmu: Support full width counting")
Suggested-by: Jim Mattson <jmattson@google.com>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20200710152559.1645827-1-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-10 12:52:56 -04:00
Thomas Gleixner
c3f08ed150 x86/kvm/svm: Use uninstrumented wrmsrl() to restore GS
On guest exit MSR_GS_BASE contains whatever the guest wrote to it and the
first action after returning from the ASM code is to set it to the host
kernel value. This uses wrmsrl() which is interesting at least.

wrmsrl() is either using native_write_msr() or the paravirt variant. The
XEN_PV code is uninteresting as nested SVM in a XEN_PV guest does not work.

But native_write_msr() can be placed out of line by the compiler especially
when paravirtualization is enabled in the kernel configuration. The
function is marked notrace, but still can be probed if
CONFIG_KPROBE_EVENTS_ON_NOTRACE is enabled.

That would be a fatal problem as kprobe events use per-CPU variables which
are GS based and would be accessed with the guest GS. Depending on the GS
value this would either explode in colorful ways or lead to completely
undebugable data corruption.

Aside of that native_write_msr() contains a tracepoint which objtool
complains about as it is invoked from the noinstr section.

As this cannot run inside a XEN_PV guest there is no point in using
wrmsrl(). Use native_wrmsrl() instead which is just a plain native WRMSR
without tracing or anything else attached.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Juergen Gross <jgross@suse.com>
Message-Id: <20200708195322.244847377@linutronix.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-09 07:08:41 -04:00
Thomas Gleixner
135961e0a7 x86/kvm/svm: Move guest enter/exit into .noinstr.text
Move the functions which are inside the RCU off region into the
non-instrumentable text section.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>

Message-Id: <20200708195322.144607767@linutronix.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-09 07:08:41 -04:00
Thomas Gleixner
9fc975e9ef x86/kvm/svm: Add hardirq tracing on guest enter/exit
Entering guest mode is more or less the same as returning to user
space. From an instrumentation point of view both leave kernel mode and the
transition to guest or user mode reenables interrupts on the host. In user
mode an interrupt is served directly and in guest mode it causes a VM exit
which then handles or reinjects the interrupt.

The transition from guest mode or user mode to kernel mode disables
interrupts, which needs to be recorded in instrumentation to set the
correct state again.

This is important for e.g. latency analysis because otherwise the execution
time in guest or user mode would be wrongly accounted as interrupt disabled
and could trigger false positives.

Add hardirq tracing to guest enter/exit functions in the same way as it
is done in the user mode enter/exit code, respecting the RCU requirements.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>

Message-Id: <20200708195321.934715094@linutronix.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-09 07:08:39 -04:00
Thomas Gleixner
87fa7f3e98 x86/kvm: Move context tracking where it belongs
Context tracking for KVM happens way too early in the vcpu_run()
code. Anything after guest_enter_irqoff() and before guest_exit_irqoff()
cannot use RCU and should also be not instrumented.

The current way of doing this covers way too much code. Move it closer to
the actual vmenter/exit code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200708195321.724574345@linutronix.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-09 07:08:38 -04:00
Maxim Levitsky
841c2be09f kvm: x86: replace kvm_spec_ctrl_test_value with runtime test on the host
To avoid complex and in some cases incorrect logic in
kvm_spec_ctrl_test_value, just try the guest's given value on the host
processor instead, and if it doesn't #GP, allow the guest to set it.

One such case is when host CPU supports STIBP mitigation
but doesn't support IBRS (as is the case with some Zen2 AMD cpus),
and in this case we were giving guest #GP when it tried to use STIBP

The reason why can can do the host test is that IA32_SPEC_CTRL msr is
passed to the guest, after the guest sets it to a non zero value
for the first time (due to performance reasons),
and as as result of this, it is pointless to emulate #GP condition on
this first access, in a different way than what the host CPU does.

This is based on a patch from Sean Christopherson, who suggested this idea.

Fixes: 6441fa6178 ("KVM: x86: avoid incorrect writes to host MSR_IA32_SPEC_CTRL")
Cc: stable@vger.kernel.org
Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20200708115731.180097-1-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-09 07:08:38 -04:00
Xiaoyao Li
7c1b761be0 KVM: x86: Rename cpuid_update() callback to vcpu_after_set_cpuid()
The name of callback cpuid_update() is misleading that it's not about
updating CPUID settings of vcpu but updating the configurations of vcpu
based on the CPUIDs. So rename it to vcpu_after_set_cpuid().

Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Message-Id: <20200709043426.92712-5-xiaoyao.li@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-09 07:08:18 -04:00
Krish Sadhukhan
761e416934 KVM: nSVM: Check that MBZ bits in CR3 and CR4 are not set on vmrun of nested guests
According to section "Canonicalization and Consistency Checks" in APM vol. 2
the following guest state is illegal:

    "Any MBZ bit of CR3 is set."
    "Any MBZ bit of CR4 is set."

Suggeted-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Message-Id: <1594168797-29444-3-git-send-email-krish.sadhukhan@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-08 16:21:59 -04:00
Joerg Roedel
01c3b2b5cd KVM: SVM: Rename svm_nested_virtualize_tpr() to nested_svm_virtualize_tpr()
Match the naming with other nested svm functions.

No functional changes.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Message-Id: <20200625080325.28439-5-joro@8bytes.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-08 16:21:49 -04:00
Joerg Roedel
a284ba56a0 KVM: SVM: Add svm_ prefix to set/clr/is_intercept()
Make clear the symbols belong to the SVM code when they are built-in.

No functional changes.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Message-Id: <20200625080325.28439-4-joro@8bytes.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-08 16:21:48 -04:00
Joerg Roedel
06e7852c0f KVM: SVM: Add vmcb_ prefix to mark_*() functions
Make it more clear what data structure these functions operate on.

No functional changes.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Message-Id: <20200625080325.28439-3-joro@8bytes.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-08 16:21:48 -04:00
Joerg Roedel
7693b3eb53 KVM: SVM: Rename struct nested_state to svm_nested_state
Renaming is only needed in the svm.h header file.

No functional changes.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Message-Id: <20200625080325.28439-2-joro@8bytes.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-08 16:21:47 -04:00
Jim Mattson
c967118ddb kvm: x86: Set last_vmentry_cpu in vcpu_enter_guest
Since this field is now in kvm_vcpu_arch, clean things up a little by
setting it in vendor-agnostic code: vcpu_enter_guest. Note that it
must be set after the call to kvm_x86_ops.run(), since it can't be
updated before pre_sev_run().

Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Oliver Upton <oupton@google.com>
Reviewed-by: Peter Shier <pshier@google.com>
Message-Id: <20200603235623.245638-7-jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-08 16:21:46 -04:00
Jim Mattson
8a14fe4f0c kvm: x86: Move last_cpu into kvm_vcpu_arch as last_vmentry_cpu
Both the vcpu_vmx structure and the vcpu_svm structure have a
'last_cpu' field. Move the common field into the kvm_vcpu_arch
structure. For clarity, rename it to 'last_vmentry_cpu.'

Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Oliver Upton <oupton@google.com>
Reviewed-by: Peter Shier <pshier@google.com>
Message-Id: <20200603235623.245638-6-jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-08 16:21:45 -04:00
Jim Mattson
1aa561b1a4 kvm: x86: Add "last CPU" to some KVM_EXIT information
More often than not, a failed VM-entry in an x86 production
environment is induced by a defective CPU. To help identify the bad
hardware, include the id of the last logical CPU to run a vCPU in the
information provided to userspace on a KVM exit for failed VM-entry or
for KVM internal errors not associated with emulation. The presence of
this additional information is indicated by a new capability,
KVM_CAP_LAST_CPU.

Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Oliver Upton <oupton@google.com>
Reviewed-by: Peter Shier <pshier@google.com>
Message-Id: <20200603235623.245638-5-jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-08 16:21:45 -04:00
Jim Mattson
242636343c kvm: svm: Always set svm->last_cpu on VMRUN
Previously, this field was only set when using SEV. Set it for all
vCPU configurations, so that it can be communicated to userspace for
diagnosing potential hardware errors.

Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Oliver Upton <oupton@google.com>
Reviewed-by: Peter Shier <pshier@google.com>
Message-Id: <20200603235623.245638-3-jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-08 16:21:43 -04:00
Jim Mattson
73cd6e5f7f kvm: svm: Prefer vcpu->cpu to raw_smp_processor_id()
The current logical processor id is cached in vcpu->cpu. Use it
instead of raw_smp_processor_id() when a kvm_vcpu struct is available.

Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Oliver Upton <oupton@google.com>
Message-Id: <20200603235623.245638-2-jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-08 16:21:42 -04:00
Paolo Bonzini
a8d908b587 KVM: x86: report sev_pin_memory errors with PTR_ERR
Callers of sev_pin_memory() treat
NULL differently:

sev_launch_secret()/svm_register_enc_region() return -ENOMEM
sev_dbg_crypt() returns -EFAULT.

Switching to ERR_PTR() preserves the error and enables cleaner reporting of
different kinds of failures.

Suggested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-08 16:21:42 -04:00
John Hubbard
dc42c8ae0a KVM: SVM: convert get_user_pages() --> pin_user_pages()
This code was using get_user_pages*(), in a "Case 2" scenario
(DMA/RDMA), using the categorization from [1]. That means that it's
time to convert the get_user_pages*() + put_page() calls to
pin_user_pages*() + unpin_user_pages() calls.

There is some helpful background in [2]: basically, this is a small
part of fixing a long-standing disconnect between pinning pages, and
file systems' use of those pages.

[1] Documentation/core-api/pin_user_pages.rst

[2] "Explicit pinning of user-space pages":
    https://lwn.net/Articles/807108/

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Wanpeng Li <wanpengli@tencent.com>
Cc: Jim Mattson <jmattson@google.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: x86@kernel.org
Cc: kvm@vger.kernel.org
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Message-Id: <20200526062207.1360225-3-jhubbard@nvidia.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-08 16:21:41 -04:00
John Hubbard
78824fabc7 KVM: SVM: fix svn_pin_memory()'s use of get_user_pages_fast()
There are two problems in svn_pin_memory():

1) The return value of get_user_pages_fast() is stored in an
unsigned long, although the declared return value is of type int.
This will not cause any symptoms, but it is misleading.
Fix this by changing the type of npinned to "int".

2) The number of pages passed into get_user_pages_fast() is stored
in an unsigned long, even though get_user_pages_fast() accepts an
int. This means that it is possible to silently overflow the number
of pages.

Fix this by adding a WARN_ON_ONCE() and an early error return. The
npages variable is left as an unsigned long for convenience in
checking for overflow.

Fixes: 89c5058090 ("KVM: SVM: Add support for KVM_SEV_LAUNCH_UPDATE_DATA command")
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Wanpeng Li <wanpengli@tencent.com>
Cc: Jim Mattson <jmattson@google.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: x86@kernel.org
Cc: kvm@vger.kernel.org
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Message-Id: <20200526062207.1360225-2-jhubbard@nvidia.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-08 16:21:41 -04:00
Krish Sadhukhan
1aef8161b3 KVM: nSVM: Check that DR6[63:32] and DR7[64:32] are not set on vmrun of nested guests
According to section "Canonicalization and Consistency Checks" in APM vol. 2
the following guest state is illegal:

    "DR6[63:32] are not zero."
    "DR7[63:32] are not zero."
    "Any MBZ bit of EFER is set."

Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Message-Id: <20200522221954.32131-3-krish.sadhukhan@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-08 16:21:41 -04:00
Peter Xu
12bc2132b1 KVM: X86: Do the same ignore_msrs check for feature msrs
Logically the ignore_msrs and report_ignored_msrs should also apply to feature
MSRs.  Add them in.

Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20200622220442.21998-3-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-08 16:21:40 -04:00
Qian Cai
b95273f127 kvm/svm: disable KCSAN for svm_vcpu_run()
For some reasons, running a simple qemu-kvm command with KCSAN will
reset AMD hosts. It turns out svm_vcpu_run() could not be instrumented.
Disable it for now.

 # /usr/libexec/qemu-kvm -name ubuntu-18.04-server-cloudimg -cpu host
	-smp 2 -m 2G -hda ubuntu-18.04-server-cloudimg.qcow2

=== console output ===
Kernel 5.6.0-next-20200408+ on an x86_64

hp-dl385g10-05 login:

<...host reset...>

HPE ProLiant System BIOS A40 v1.20 (03/09/2018)
(C) Copyright 1982-2018 Hewlett Packard Enterprise Development LP
Early system initialization, please wait...

Signed-off-by: Qian Cai <cai@lca.pw>
Message-Id: <20200415153709.1559-1-cai@lca.pw>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-15 09:32:58 -04:00
Linus Torvalds
076f14be7f The X86 entry, exception and interrupt code rework
This all started about 6 month ago with the attempt to move the Posix CPU
 timer heavy lifting out of the timer interrupt code and just have lockless
 quick checks in that code path. Trivial 5 patches.
 
 This unearthed an inconsistency in the KVM handling of task work and the
 review requested to move all of this into generic code so other
 architectures can share.
 
 Valid request and solved with another 25 patches but those unearthed
 inconsistencies vs. RCU and instrumentation.
 
 Digging into this made it obvious that there are quite some inconsistencies
 vs. instrumentation in general. The int3 text poke handling in particular
 was completely unprotected and with the batched update of trace events even
 more likely to expose to endless int3 recursion.
 
 In parallel the RCU implications of instrumenting fragile entry code came
 up in several discussions.
 
 The conclusion of the X86 maintainer team was to go all the way and make
 the protection against any form of instrumentation of fragile and dangerous
 code pathes enforcable and verifiable by tooling.
 
 A first batch of preparatory work hit mainline with commit d5f744f9a2.
 
 The (almost) full solution introduced a new code section '.noinstr.text'
 into which all code which needs to be protected from instrumentation of all
 sorts goes into. Any call into instrumentable code out of this section has
 to be annotated. objtool has support to validate this. Kprobes now excludes
 this section fully which also prevents BPF from fiddling with it and all
 'noinstr' annotated functions also keep ftrace off. The section, kprobes
 and objtool changes are already merged.
 
 The major changes coming with this are:
 
     - Preparatory cleanups
 
     - Annotating of relevant functions to move them into the noinstr.text
       section or enforcing inlining by marking them __always_inline so the
       compiler cannot misplace or instrument them.
 
     - Splitting and simplifying the idtentry macro maze so that it is now
       clearly separated into simple exception entries and the more
       interesting ones which use interrupt stacks and have the paranoid
       handling vs. CR3 and GS.
 
     - Move quite some of the low level ASM functionality into C code:
 
        - enter_from and exit to user space handling. The ASM code now calls
          into C after doing the really necessary ASM handling and the return
 	 path goes back out without bells and whistels in ASM.
 
        - exception entry/exit got the equivivalent treatment
 
        - move all IRQ tracepoints from ASM to C so they can be placed as
          appropriate which is especially important for the int3 recursion
          issue.
 
     - Consolidate the declaration and definition of entry points between 32
       and 64 bit. They share a common header and macros now.
 
     - Remove the extra device interrupt entry maze and just use the regular
       exception entry code.
 
     - All ASM entry points except NMI are now generated from the shared header
       file and the corresponding macros in the 32 and 64 bit entry ASM.
 
     - The C code entry points are consolidated as well with the help of
       DEFINE_IDTENTRY*() macros. This allows to ensure at one central point
       that all corresponding entry points share the same semantics. The
       actual function body for most entry points is in an instrumentable
       and sane state.
 
       There are special macros for the more sensitive entry points,
       e.g. INT3 and of course the nasty paranoid #NMI, #MCE, #DB and #DF.
       They allow to put the whole entry instrumentation and RCU handling
       into safe places instead of the previous pray that it is correct
       approach.
 
     - The INT3 text poke handling is now completely isolated and the
       recursion issue banned. Aside of the entry rework this required other
       isolation work, e.g. the ability to force inline bsearch.
 
     - Prevent #DB on fragile entry code, entry relevant memory and disable
       it on NMI, #MC entry, which allowed to get rid of the nested #DB IST
       stack shifting hackery.
 
     - A few other cleanups and enhancements which have been made possible
       through this and already merged changes, e.g. consolidating and
       further restricting the IDT code so the IDT table becomes RO after
       init which removes yet another popular attack vector
 
     - About 680 lines of ASM maze are gone.
 
 There are a few open issues:
 
    - An escape out of the noinstr section in the MCE handler which needs
      some more thought but under the aspect that MCE is a complete
      trainwreck by design and the propability to survive it is low, this was
      not high on the priority list.
 
    - Paravirtualization
 
      When PV is enabled then objtool complains about a bunch of indirect
      calls out of the noinstr section. There are a few straight forward
      ways to fix this, but the other issues vs. general correctness were
      more pressing than parawitz.
 
    - KVM
 
      KVM is inconsistent as well. Patches have been posted, but they have
      not yet been commented on or picked up by the KVM folks.
 
    - IDLE
 
      Pretty much the same problems can be found in the low level idle code
      especially the parts where RCU stopped watching. This was beyond the
      scope of the more obvious and exposable problems and is on the todo
      list.
 
 The lesson learned from this brain melting exercise to morph the evolved
 code base into something which can be validated and understood is that once
 again the violation of the most important engineering principle
 "correctness first" has caused quite a few people to spend valuable time on
 problems which could have been avoided in the first place. The "features
 first" tinkering mindset really has to stop.
 
 With that I want to say thanks to everyone involved in contributing to this
 effort. Special thanks go to the following people (alphabetical order):
 
    Alexandre Chartre
    Andy Lutomirski
    Borislav Petkov
    Brian Gerst
    Frederic Weisbecker
    Josh Poimboeuf
    Juergen Gross
    Lai Jiangshan
    Macro Elver
    Paolo Bonzini
    Paul McKenney
    Peter Zijlstra
    Vitaly Kuznetsov
    Will Deacon
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Merge tag 'x86-entry-2020-06-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 entry updates from Thomas Gleixner:
 "The x86 entry, exception and interrupt code rework

  This all started about 6 month ago with the attempt to move the Posix
  CPU timer heavy lifting out of the timer interrupt code and just have
  lockless quick checks in that code path. Trivial 5 patches.

  This unearthed an inconsistency in the KVM handling of task work and
  the review requested to move all of this into generic code so other
  architectures can share.

  Valid request and solved with another 25 patches but those unearthed
  inconsistencies vs. RCU and instrumentation.

  Digging into this made it obvious that there are quite some
  inconsistencies vs. instrumentation in general. The int3 text poke
  handling in particular was completely unprotected and with the batched
  update of trace events even more likely to expose to endless int3
  recursion.

  In parallel the RCU implications of instrumenting fragile entry code
  came up in several discussions.

  The conclusion of the x86 maintainer team was to go all the way and
  make the protection against any form of instrumentation of fragile and
  dangerous code pathes enforcable and verifiable by tooling.

  A first batch of preparatory work hit mainline with commit
  d5f744f9a2 ("Pull x86 entry code updates from Thomas Gleixner")

  That (almost) full solution introduced a new code section
  '.noinstr.text' into which all code which needs to be protected from
  instrumentation of all sorts goes into. Any call into instrumentable
  code out of this section has to be annotated. objtool has support to
  validate this.

  Kprobes now excludes this section fully which also prevents BPF from
  fiddling with it and all 'noinstr' annotated functions also keep
  ftrace off. The section, kprobes and objtool changes are already
  merged.

  The major changes coming with this are:

    - Preparatory cleanups

    - Annotating of relevant functions to move them into the
      noinstr.text section or enforcing inlining by marking them
      __always_inline so the compiler cannot misplace or instrument
      them.

    - Splitting and simplifying the idtentry macro maze so that it is
      now clearly separated into simple exception entries and the more
      interesting ones which use interrupt stacks and have the paranoid
      handling vs. CR3 and GS.

    - Move quite some of the low level ASM functionality into C code:

       - enter_from and exit to user space handling. The ASM code now
         calls into C after doing the really necessary ASM handling and
         the return path goes back out without bells and whistels in
         ASM.

       - exception entry/exit got the equivivalent treatment

       - move all IRQ tracepoints from ASM to C so they can be placed as
         appropriate which is especially important for the int3
         recursion issue.

    - Consolidate the declaration and definition of entry points between
      32 and 64 bit. They share a common header and macros now.

    - Remove the extra device interrupt entry maze and just use the
      regular exception entry code.

    - All ASM entry points except NMI are now generated from the shared
      header file and the corresponding macros in the 32 and 64 bit
      entry ASM.

    - The C code entry points are consolidated as well with the help of
      DEFINE_IDTENTRY*() macros. This allows to ensure at one central
      point that all corresponding entry points share the same
      semantics. The actual function body for most entry points is in an
      instrumentable and sane state.

      There are special macros for the more sensitive entry points, e.g.
      INT3 and of course the nasty paranoid #NMI, #MCE, #DB and #DF.
      They allow to put the whole entry instrumentation and RCU handling
      into safe places instead of the previous pray that it is correct
      approach.

    - The INT3 text poke handling is now completely isolated and the
      recursion issue banned. Aside of the entry rework this required
      other isolation work, e.g. the ability to force inline bsearch.

    - Prevent #DB on fragile entry code, entry relevant memory and
      disable it on NMI, #MC entry, which allowed to get rid of the
      nested #DB IST stack shifting hackery.

    - A few other cleanups and enhancements which have been made
      possible through this and already merged changes, e.g.
      consolidating and further restricting the IDT code so the IDT
      table becomes RO after init which removes yet another popular
      attack vector

    - About 680 lines of ASM maze are gone.

  There are a few open issues:

   - An escape out of the noinstr section in the MCE handler which needs
     some more thought but under the aspect that MCE is a complete
     trainwreck by design and the propability to survive it is low, this
     was not high on the priority list.

   - Paravirtualization

     When PV is enabled then objtool complains about a bunch of indirect
     calls out of the noinstr section. There are a few straight forward
     ways to fix this, but the other issues vs. general correctness were
     more pressing than parawitz.

   - KVM

     KVM is inconsistent as well. Patches have been posted, but they
     have not yet been commented on or picked up by the KVM folks.

   - IDLE

     Pretty much the same problems can be found in the low level idle
     code especially the parts where RCU stopped watching. This was
     beyond the scope of the more obvious and exposable problems and is
     on the todo list.

  The lesson learned from this brain melting exercise to morph the
  evolved code base into something which can be validated and understood
  is that once again the violation of the most important engineering
  principle "correctness first" has caused quite a few people to spend
  valuable time on problems which could have been avoided in the first
  place. The "features first" tinkering mindset really has to stop.

  With that I want to say thanks to everyone involved in contributing to
  this effort. Special thanks go to the following people (alphabetical
  order): Alexandre Chartre, Andy Lutomirski, Borislav Petkov, Brian
  Gerst, Frederic Weisbecker, Josh Poimboeuf, Juergen Gross, Lai
  Jiangshan, Macro Elver, Paolo Bonzin,i Paul McKenney, Peter Zijlstra,
  Vitaly Kuznetsov, and Will Deacon"

* tag 'x86-entry-2020-06-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (142 commits)
  x86/entry: Force rcu_irq_enter() when in idle task
  x86/entry: Make NMI use IDTENTRY_RAW
  x86/entry: Treat BUG/WARN as NMI-like entries
  x86/entry: Unbreak __irqentry_text_start/end magic
  x86/entry: __always_inline CR2 for noinstr
  lockdep: __always_inline more for noinstr
  x86/entry: Re-order #DB handler to avoid *SAN instrumentation
  x86/entry: __always_inline arch_atomic_* for noinstr
  x86/entry: __always_inline irqflags for noinstr
  x86/entry: __always_inline debugreg for noinstr
  x86/idt: Consolidate idt functionality
  x86/idt: Cleanup trap_init()
  x86/idt: Use proper constants for table size
  x86/idt: Add comments about early #PF handling
  x86/idt: Mark init only functions __init
  x86/entry: Rename trace_hardirqs_off_prepare()
  x86/entry: Clarify irq_{enter,exit}_rcu()
  x86/entry: Remove DBn stacks
  x86/entry: Remove debug IDT frobbing
  x86/entry: Optimize local_db_save() for virt
  ...
2020-06-13 10:05:47 -07:00
Thomas Gleixner
8cd501c1fa x86/entry: Convert Machine Check to IDTENTRY_IST
Convert #MC to IDTENTRY_MCE:
  - Implement the C entry points with DEFINE_IDTENTRY_MCE
  - Emit the ASM stub with DECLARE_IDTENTRY_MCE
  - Remove the ASM idtentry in 64bit
  - Remove the open coded ASM entry code in 32bit
  - Fixup the XEN/PV code
  - Remove the old prototypes
  - Remove the error code from *machine_check_vector() as
    it is always 0 and not used by any of the functions
    it can point to. Fixup all the functions as well.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200505135314.334980426@linutronix.de
2020-06-11 15:14:57 +02:00
Paolo Bonzini
fb7333dfd8 KVM: SVM: fix calls to is_intercept
is_intercept takes an INTERCEPT_* constant, not SVM_EXIT_*; because
of this, the compiler was removing the body of the conditionals,
as if is_intercept returned 0.

This unveils a latent bug: when clearing the VINTR intercept,
int_ctl must also be changed in the L1 VMCB (svm->nested.hsave),
just like the intercept itself is also changed in the L1 VMCB.
Otherwise V_IRQ remains set and, due to the VINTR intercept being clear,
we get a spurious injection of a vector 0 interrupt on the next
L2->L1 vmexit.

Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-08 08:00:57 -04:00
Linus Torvalds
039aeb9deb ARM:
- Move the arch-specific code into arch/arm64/kvm
 - Start the post-32bit cleanup
 - Cherry-pick a few non-invasive pre-NV patches
 
 x86:
 - Rework of TLB flushing
 - Rework of event injection, especially with respect to nested virtualization
 - Nested AMD event injection facelift, building on the rework of generic code
 and fixing a lot of corner cases
 - Nested AMD live migration support
 - Optimization for TSC deadline MSR writes and IPIs
 - Various cleanups
 - Asynchronous page fault cleanups (from tglx, common topic branch with tip tree)
 - Interrupt-based delivery of asynchronous "page ready" events (host side)
 - Hyper-V MSRs and hypercalls for guest debugging
 - VMX preemption timer fixes
 
 s390:
 - Cleanups
 
 Generic:
 - switch vCPU thread wakeup from swait to rcuwait
 
 The other architectures, and the guest side of the asynchronous page fault
 work, will come next week.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "ARM:
   - Move the arch-specific code into arch/arm64/kvm

   - Start the post-32bit cleanup

   - Cherry-pick a few non-invasive pre-NV patches

  x86:
   - Rework of TLB flushing

   - Rework of event injection, especially with respect to nested
     virtualization

   - Nested AMD event injection facelift, building on the rework of
     generic code and fixing a lot of corner cases

   - Nested AMD live migration support

   - Optimization for TSC deadline MSR writes and IPIs

   - Various cleanups

   - Asynchronous page fault cleanups (from tglx, common topic branch
     with tip tree)

   - Interrupt-based delivery of asynchronous "page ready" events (host
     side)

   - Hyper-V MSRs and hypercalls for guest debugging

   - VMX preemption timer fixes

  s390:
   - Cleanups

  Generic:
   - switch vCPU thread wakeup from swait to rcuwait

  The other architectures, and the guest side of the asynchronous page
  fault work, will come next week"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (256 commits)
  KVM: selftests: fix rdtsc() for vmx_tsc_adjust_test
  KVM: check userspace_addr for all memslots
  KVM: selftests: update hyperv_cpuid with SynDBG tests
  x86/kvm/hyper-v: Add support for synthetic debugger via hypercalls
  x86/kvm/hyper-v: enable hypercalls regardless of hypercall page
  x86/kvm/hyper-v: Add support for synthetic debugger interface
  x86/hyper-v: Add synthetic debugger definitions
  KVM: selftests: VMX preemption timer migration test
  KVM: nVMX: Fix VMX preemption timer migration
  x86/kvm/hyper-v: Explicitly align hcall param for kvm_hyperv_exit
  KVM: x86/pmu: Support full width counting
  KVM: x86/pmu: Tweak kvm_pmu_get_msr to pass 'struct msr_data' in
  KVM: x86: announce KVM_FEATURE_ASYNC_PF_INT
  KVM: x86: acknowledgment mechanism for async pf page ready notifications
  KVM: x86: interrupt based APF 'page ready' event delivery
  KVM: introduce kvm_read_guest_offset_cached()
  KVM: rename kvm_arch_can_inject_async_page_present() to kvm_arch_can_dequeue_async_page_present()
  KVM: x86: extend struct kvm_vcpu_pv_apf_data with token info
  Revert "KVM: async_pf: Fix #DF due to inject "Page not Present" and "Page Ready" exceptions simultaneously"
  KVM: VMX: Replace zero-length array with flexible-array
  ...
2020-06-03 15:13:47 -07:00
Christoph Hellwig
88dca4ca5a mm: remove the pgprot argument to __vmalloc
The pgprot argument to __vmalloc is always PAGE_KERNEL now, so remove it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Michael Kelley <mikelley@microsoft.com> [hyperv]
Acked-by: Gao Xiang <xiang@kernel.org> [erofs]
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Wei Liu <wei.liu@kernel.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Link: http://lkml.kernel.org/r/20200414131348.444715-22-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-02 10:59:11 -07:00
Wei Wang
cbd717585b KVM: x86/pmu: Tweak kvm_pmu_get_msr to pass 'struct msr_data' in
Change kvm_pmu_get_msr() to get the msr_data struct, as the host_initiated
field from the struct could be used by get_msr. This also makes this API
consistent with kvm_pmu_set_msr. No functional changes.

Signed-off-by: Wei Wang <wei.w.wang@intel.com>
Message-Id: <20200529074347.124619-2-like.xu@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01 04:26:08 -04:00