Remove duplicate expression in nested_vmx_prepare_msr_bitmap, and make
the register names clearer in hardware_setup.
Suggested-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[Resolved rebase conflict after removing Intel PT. - Radim]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
The bulk of the MSR bitmap is either immutable, or can be copied from
the L1 bitmap. By initializing it at VMXON time, and copying the mutable
parts one long at a time on vmentry (rather than one bit), about 4000
clock cycles (30%) can be saved on a nested VMLAUNCH/VMRESUME.
The resulting for loop only has four iterations, so it is cheap enough
to reinitialize the MSR write bitmaps on every iteration, and it makes
the code simpler.
Suggested-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
The APICv-enabled MSR bitmap is a superset of the APICv-disabled bitmap.
Make that obvious in vmx_disable_intercept_msr_x2apic.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[Resolved rebase conflict after removing Intel PT. - Radim]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
The POSTED_INTR_NV field is constant (though it differs between the vmcs01 and
vmcs02), there is no need to reload it on vmexit to L1.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
These fields are also simple copies of the data in the vmcs12 struct.
For some of them, prepare_vmcs02 was skipping the copy when the field
was unused. In prepare_vmcs02_full, we copy them always as long as the
field exists on the host, because the corresponding execution control
might be one of the shadowed fields.
Optimization opportunities remain for MSRs that, depending on the
entry/exit controls, have to be copied from either the vmcs01 or
the vmcs12: EFER (whose value is partly stored in the entry controls
too), PAT, DEBUGCTL (and also DR7). Before moving these three and
the entry/exit controls to prepare_vmcs02_full, KVM would have to set
dirty_vmcs12 on writes to the L1 MSRs.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
This part is separate for ease of review, because git prefers to move
prepare_vmcs02 below the initial long sequence of vmcs_write* operations.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
VMCS12 fields that are not handled through shadow VMCS are rarely
written, and thus they are also almost constant in the vmcs02. We can
thus optimize prepare_vmcs02 by skipping all the work for non-shadowed
fields in the common case.
This patch introduces the (pretty simple) tracking infrastructure; the
next patches will move work to prepare_vmcs02_full and save a few hundred
clock cycles per VMRESUME on a Haswell Xeon E5 system:
before after
cpuid 14159 13869
vmcall 15290 14951
inl_from_kernel 17703 17447
outl_to_kernel 16011 14692
self_ipi_sti_nop 16763 15825
self_ipi_tpr_sti_nop 17341 15935
wr_tsc_adjust_msr 14510 14264
rd_tsc_adjust_msr 15018 14311
mmio-wildcard-eventfd:pci-mem 16381 14947
mmio-datamatch-eventfd:pci-mem 18620 17858
portio-wildcard-eventfd:pci-io 15121 14769
portio-datamatch-eventfd:pci-io 15761 14831
(average savings 748, stdev 460).
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
The vmcs_field_to_offset_table was a rather sparse table of short
integers with a maximum index of 0x6c16, amounting to 55342 bytes. Now
that we are considering support for multiple VMCS12 formats, it would
be unfortunate to replicate that large, sparse table. Rotating the
field encoding (as a 16-bit integer) left by 6 reduces that table to
5926 bytes.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Per the SDM, "[VMCS] Fields are grouped by width (16-bit, 32-bit,
etc.) and type (guest-state, host-state, etc.)." Previously, the width
was indicated by vmcs_field_type. To avoid confusion when we start
dealing with both field width and field type, change vmcs_field_type
to vmcs_field_width.
Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
This is the highest index value used in any supported VMCS12 field
encoding. It is used to populate the IA32_VMX_VMCS_ENUM MSR.
Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Because all fields can be read/written with a single vmread/vmwrite on
64-bit kernels, the switch statements in copy_vmcs12_to_shadow and
copy_shadow_to_vmcs12 are unnecessary.
What I did in this patch is to copy the two parts of 64-bit fields
separately on 32-bit kernels, to keep all complicated #ifdef-ery
in init_vmcs_shadow_fields. The disadvantage is that 64-bit fields
have to be listed separately in shadow_read_only/read_write_fields,
but those are few and we can validate the arrays when building the
VMREAD and VMWRITE bitmaps. This saves a few hundred clock cycles
per nested vmexit.
However there is still a "switch" in vmcs_read_any and vmcs_write_any.
So, while at it, this patch reorders the fields by type, hoping that
the branch predictor appreciates it.
Cc: Jim Mattson <jmattson@google.com>
Cc: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Compared to when VMCS shadowing was added to KVM, we are reading/writing
a few more fields: the PML index, the interrupt status and the preemption
timer value. The first two are because we are exposing more features
to nested guests, the preemption timer is simply because we have grown
a new optimization. Adding them to the shadow VMCS field lists reduces
the cost of a vmexit by about 1000 clock cycles for each field that exists
on bare metal.
On the other hand, the guest BNDCFGS and TSC offset are not written on
fast paths, so remove them.
Suggested-by: Jim Mattson <jmattson@google.com>
Cc: Jim Mattson <jmattson@google.com>
Cc: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
- add the virtio-ccw transport for kvmconfig
- more debug tracing for cpu model
- cleanups and fixes
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Merge tag 'kvm-s390-next-4.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux
KVM: s390: Fixes and features for 4.16
- add the virtio-ccw transport for kvmconfig
- more debug tracing for cpu model
- cleanups and fixes
Consider the following scenario:
1. CPU A calls vmx_deliver_nested_posted_interrupt() to send an IPI
to CPU B via virtual posted-interrupt mechanism.
2. CPU B is currently executing L2 guest.
3. vmx_deliver_nested_posted_interrupt() calls
kvm_vcpu_trigger_posted_interrupt() which will note that
vcpu->mode == IN_GUEST_MODE.
4. Assume that before CPU A sends the physical POSTED_INTR_NESTED_VECTOR
IPI, CPU B exits from L2 to L0 during event-delivery
(valid IDT-vectoring-info).
5. CPU A now sends the physical IPI. The IPI is received in host and
it's handler (smp_kvm_posted_intr_nested_ipi()) does nothing.
6. Assume that before CPU A sets pi_pending=true and KVM_REQ_EVENT,
CPU B continues to run in L0 and reach vcpu_enter_guest(). As
KVM_REQ_EVENT is not set yet, vcpu_enter_guest() will continue and resume
L2 guest.
7. At this point, CPU A sets pi_pending=true and KVM_REQ_EVENT but
it's too late! CPU B already entered L2 and KVM_REQ_EVENT will only be
consumed at next L2 entry!
Another scenario to consider:
1. CPU A calls vmx_deliver_nested_posted_interrupt() to send an IPI
to CPU B via virtual posted-interrupt mechanism.
2. Assume that before CPU A calls kvm_vcpu_trigger_posted_interrupt(),
CPU B is at L0 and is about to resume into L2. Further assume that it is
in vcpu_enter_guest() after check for KVM_REQ_EVENT.
3. At this point, CPU A calls kvm_vcpu_trigger_posted_interrupt() which
will note that vcpu->mode != IN_GUEST_MODE. Therefore, do nothing and
return false. Then, will set pi_pending=true and KVM_REQ_EVENT.
4. Now CPU B continue and resumes into L2 guest without processing
the posted-interrupt until next L2 entry!
To fix both issues, we just need to change
vmx_deliver_nested_posted_interrupt() to set pi_pending=true and
KVM_REQ_EVENT before calling kvm_vcpu_trigger_posted_interrupt().
It will fix the first scenario by chaging step (6) to note that
KVM_REQ_EVENT and pi_pending=true and therefore process
nested posted-interrupt.
It will fix the second scenario by two possible ways:
1. If kvm_vcpu_trigger_posted_interrupt() is called while CPU B has changed
vcpu->mode to IN_GUEST_MODE, physical IPI will be sent and will be received
when CPU resumes into L2.
2. If kvm_vcpu_trigger_posted_interrupt() is called while CPU B hasn't yet
changed vcpu->mode to IN_GUEST_MODE, then after CPU B will change
vcpu->mode it will call kvm_request_pending() which will return true and
therefore force another round of vcpu_enter_guest() which will note that
KVM_REQ_EVENT and pi_pending=true and therefore process nested
posted-interrupt.
Cc: stable@vger.kernel.org
Fixes: 705699a139 ("KVM: nVMX: Enable nested posted interrupt processing")
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
[Add kvm_vcpu_kick to also handle the case where L1 doesn't intercept L2 HLT
and L2 executes HLT instruction. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Before each vmentry to guest, vcpu_enter_guest() calls sync_pir_to_irr()
which calls vmx_hwapic_irr_update() to update RVI.
Currently, vmx_hwapic_irr_update() contains a tweak in case it is called
when CPU is running L2 and L1 don't intercept external-interrupts.
In that case, code injects interrupt directly into L2 instead of
updating RVI.
Besides being hacky (wouldn't expect function updating RVI to also
inject interrupt), it also doesn't handle this case correctly.
The code contains several issues:
1. When code calls kvm_queue_interrupt() it just passes it max_irr which
represents the highest IRR currently pending in L1 LAPIC.
This is problematic as interrupt was injected to guest but it's bit is
still set in LAPIC IRR instead of being cleared from IRR and set in ISR.
2. Code doesn't check if LAPIC PPR is set to accept an interrupt of
max_irr priority. It just checks if interrupts are enabled in guest with
vmx_interrupt_allowed().
To fix the above issues:
1. Simplify vmx_hwapic_irr_update() to just update RVI.
Note that this shouldn't happen when CPU is running L2
(See comment in code).
2. Since now vmx_hwapic_irr_update() only does logic for L1
virtual-interrupt-delivery, inject_pending_event() should be the
one responsible for injecting the interrupt directly into L2.
Therefore, change kvm_cpu_has_injectable_intr() to check L1
LAPIC when CPU is running L2.
3. Change vmx_sync_pir_to_irr() to set KVM_REQ_EVENT when L1
has a pending injectable interrupt.
Fixes: 963fee1656 ("KVM: nVMX: Fix virtual interrupt delivery
injection")
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Signed-off-by: Liam Merwick <liam.merwick@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
In case posted-interrupt was delivered to CPU while it is in host
(outside guest), then posted-interrupt delivery will be done by
calling sync_pir_to_irr() at vmentry after interrupts are disabled.
sync_pir_to_irr() will check vmx->pi_desc.control ON bit and if
set, it will sync vmx->pi_desc.pir to IRR and afterwards update RVI to
ensure virtual-interrupt-delivery will dispatch interrupt to guest.
However, it is possible that L1 will receive a posted-interrupt while
CPU runs at host and is about to enter L2. In this case, the call to
sync_pir_to_irr() will indeed update the L1's APIC IRR but
vcpu_enter_guest() will then just resume into L2 guest without
re-evaluating if it should exit from L2 to L1 as a result of this
new pending L1 event.
To address this case, if sync_pir_to_irr() has a new L1 injectable
interrupt and CPU is running L2, we force exit GUEST_MODE which will
result in another iteration of vcpu_run() run loop which will call
kvm_vcpu_running() which will call check_nested_events() which will
handle the pending L1 event properly.
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Signed-off-by: Liam Merwick <liam.merwick@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
sync_pir_to_irr() is only called if vcpu->arch.apicv_active()==true.
In case it is false, VMX code make sure to set sync_pir_to_irr
to NULL.
Therefore, having SVM stubs allows to remove check for if
sync_pir_to_irr != NULL from all calling sites.
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com>
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
[Return highest IRR in the SVM case. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
kvm_clear_exception_queue() should clear pending exception.
This also includes exceptions which were only marked pending but not
yet injected. This is because exception.pending is used for both L1
and L2 to determine if an exception should be raised to guest.
Note that an exception which is pending but not yet injected will
be raised again once the guest will be resumed.
Consider the following scenario:
1) L0 KVM with ignore_msrs=false.
2) L1 prepare vmcs12 with the following:
a) No intercepts on MSR (MSR_BITMAP exist and is filled with 0).
b) No intercept for #GP.
c) vmx-preemption-timer is configured.
3) L1 enters into L2.
4) L2 reads an unhandled MSR that exists in MSR_BITMAP
(such as 0x1fff).
L2 RDMSR could be handled as described below:
1) L2 exits to L0 on RDMSR and calls handle_rdmsr().
2) handle_rdmsr() calls kvm_inject_gp() which sets
KVM_REQ_EVENT, exception.pending=true and exception.injected=false.
3) vcpu_enter_guest() consumes KVM_REQ_EVENT and calls
inject_pending_event() which calls vmx_check_nested_events()
which sees that exception.pending=true but
nested_vmx_check_exception() returns 0 and therefore does nothing at
this point. However let's assume it later sees vmx-preemption-timer
expired and therefore exits from L2 to L1 by calling
nested_vmx_vmexit().
4) nested_vmx_vmexit() calls prepare_vmcs12()
which calls vmcs12_save_pending_event() but it does nothing as
exception.injected is false. Also prepare_vmcs12() calls
kvm_clear_exception_queue() which does nothing as
exception.injected is already false.
5) We now return from vmx_check_nested_events() with 0 while still
having exception.pending=true!
6) Therefore inject_pending_event() continues
and we inject L2 exception to L1!...
This commit will fix above issue by changing step (4) to
clear exception.pending in kvm_clear_exception_queue().
Fixes: 664f8e26b0 ("KVM: X86: Fix loss of exception which has not yet been injected")
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
... just like in vmx_set_msr().
No functionality change.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Some reserved pages, such as those from NVDIMM DAX devices, are not
for MMIO, and can be mapped with cached memory type for better
performance. However, the above check misconceives those pages as
MMIO. Because KVM maps MMIO pages with UC memory type, the
performance of guest accesses to those pages would be harmed.
Therefore, we check the host memory type in addition and only treat
UC/UC-/WC pages as MMIO.
Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
Reported-by: Cuevas Escareno, Ivan D <ivan.d.cuevas.escareno@intel.com>
Reported-by: Kumar, Karthik <karthik.kumar@intel.com>
Reviewed-by: Xiao Guangrong <xiaoguangrong@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Check whether the PAT memory type of a pfn cannot be overridden by
MTRR UC memory type, i.e. the PAT memory type is UC, UC- or WC. This
function will be used by KVM to distinguish MMIO pfns and give them
UC memory type in the EPT page tables (on Intel processors, EPT
memory types work like MTRRs).
Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
Reviewed-by: Xiao Guangrong <xiaoguangrong@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Avoid reverse dependencies. Instead, SEV will only be enabled if
the PSP driver is available.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
This part of Secure Encrypted Virtualization (SEV) patch series focuses on KVM
changes required to create and manage SEV guests.
SEV is an extension to the AMD-V architecture which supports running encrypted
virtual machine (VMs) under the control of a hypervisor. Encrypted VMs have their
pages (code and data) secured such that only the guest itself has access to
unencrypted version. Each encrypted VM is associated with a unique encryption key;
if its data is accessed to a different entity using a different key the encrypted
guest's data will be incorrectly decrypted, leading to unintelligible data.
This security model ensures that hypervisor will no longer able to inspect or
alter any guest code or data.
The key management of this feature is handled by a separate processor known as
the AMD Secure Processor (AMD-SP) which is present on AMD SOCs. The SEV Key
Management Specification (see below) provides a set of commands which can be
used by hypervisor to load virtual machine keys through the AMD-SP driver.
The patch series adds a new ioctl in KVM driver (KVM_MEMORY_ENCRYPT_OP). The
ioctl will be used by qemu to issue SEV guest-specific commands defined in Key
Management Specification.
The following links provide additional details:
AMD Memory Encryption white paper:
http://amd-dev.wpengine.netdna-cdn.com/wordpress/media/2013/12/AMD_Memory_Encryption_Whitepaper_v7-Public.pdf
AMD64 Architecture Programmer's Manual:
http://support.amd.com/TechDocs/24593.pdf
SME is section 7.10
SEV is section 15.34
SEV Key Management:
http://support.amd.com/TechDocs/55766_SEV-KM API_Specification.pdf
KVM Forum Presentation:
http://www.linux-kvm.org/images/7/74/02x08A-Thomas_Lendacky-AMDs_Virtualizatoin_Memory_Encryption_Technology.pdf
SEV Guest BIOS support:
SEV support has been add to EDKII/OVMF BIOS
https://github.com/tianocore/edk2
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
xsetbv can be expensive when running on nested virtualization, try to
avoid it.
Reviewed-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com>
Reviewed-by: Quan Xu <quan.xu0@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
syzkaller reported:
WARNING: CPU: 0 PID: 12927 at arch/x86/kernel/traps.c:780 do_debug+0x222/0x250
CPU: 0 PID: 12927 Comm: syz-executor Tainted: G OE 4.15.0-rc2+ #16
RIP: 0010:do_debug+0x222/0x250
Call Trace:
<#DB>
debug+0x3e/0x70
RIP: 0010:copy_user_enhanced_fast_string+0x10/0x20
</#DB>
_copy_from_user+0x5b/0x90
SyS_timer_create+0x33/0x80
entry_SYSCALL_64_fastpath+0x23/0x9a
The testcase sets a watchpoint (with perf_event_open) on a buffer that is
passed to timer_create() as the struct sigevent argument. In timer_create(),
copy_from_user()'s rep movsb triggers the BP. The testcase also sets
the debug registers for the guest.
However, KVM only restores host debug registers when the host has active
watchpoints, which triggers a race condition when running the testcase with
multiple threads. The guest's DR6.BS bit can escape to the host before
another thread invokes timer_create(), and do_debug() complains.
The fix is to respect do_debug()'s dr6 invariant when leaving KVM.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
When running on a virtual machine, IPIs are expensive when the target
CPU is sleeping. Thus, it is nice to be able to avoid them for TLB
shootdowns. KVM can just do the flush via INVVPID on the guest's behalf
the next time the CPU is scheduled.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
[Use "&" to test the bit instead of "==". - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Introduce a new bool invalidate_gpa argument to kvm_x86_ops->tlb_flush,
it will be used by later patches to just flush guest tlb.
For VMX, this will use INVVPID instead of INVEPT, which will invalidate
combined mappings while keeping guest-physical mappings.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Remote TLB flush does a busy wait which is fine in bare-metal
scenario. But with-in the guest, the vcpus might have been pre-empted or
blocked. In this scenario, the initator vcpu would end up busy-waiting
for a long amount of time; it also consumes CPU unnecessarily to wake
up the target of the shootdown.
This patch set adds support for KVM's new paravirtualized TLB flush;
remote TLB flush does not wait for vcpus that are sleeping, instead
KVM will flush the TLB as soon as the vCPU starts running again.
The improvement is clearly visible when the host is overcommitted; in this
case, the PV TLB flush (in addition to avoiding the wait on the main CPU)
prevents preempted vCPUs from stealing precious execution time from the
running ones.
Testing on a Xeon Gold 6142 2.6GHz 2 sockets, 32 cores, 64 threads,
so 64 pCPUs, and each VM is 64 vCPUs.
ebizzy -M
vanilla optimized boost
1VM 46799 48670 4%
2VM 23962 42691 78%
3VM 16152 37539 132%
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
The next patch will add another bit to the preempted field in
kvm_steal_time. Define a constant for bit 0 (the only one that is
currently used).
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
"wq" is not used at all. "cpuflags" can be access directly via the vcpu,
just as "float_int" via vcpu->kvm.
While at it, reuse _set_cpuflag() to make the code look nicer.
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20180108193747.10818-1-david@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
make kvmconfig currently does not select CONFIG_S390_GUEST. Since
the virtio-ccw transport depends on CONFIG_S390_GUEST, we want
to add CONFIG_S390_GUEST to kvmconfig.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
It is not required to take to a lock to protect access to the cpuflags
of the local interrupt structure of a vcpu as the performed operation
is an atomic_or.
Signed-off-by: Michael Mueller <mimu@linux.vnet.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
The cpu model already traces the cpu facilities, the ibc and
guest CPU ids. We should do the same for the cpu features (on
success only).
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
commit a03825bbd0 ("KVM: s390: use kvm->created_vcpus") introduced
kvm->created_vcpus to avoid races with the existing kvm->online_vcpus
scheme. One place was "forgotten" and one new place was "added".
Let's fix those.
Reported-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Fixes: 4e0b1ab72b ("KVM: s390: gs support for kvm guests")
Fixes: a03825bbd0 ("KVM: s390: use kvm->created_vcpus")
gmap_mprotect_notify() refuses shadow gmaps. Turns out that
a) gmap_protect_range()
b) gmap_read_table()
c) gmap_pte_op_walk()
Are never called for gmap shadows. And never should be. This dates back
to gmap shadow prototypes where we allowed to call mprotect_notify() on
the gmap shadow (to get notified about the prefix pages getting removed).
This is avoided by always getting notified about any change on the gmap
shadow.
The only real function for walking page tables on shadow gmaps is
gmap_table_walk().
So, essentially, these functions should never get called and
gmap_pte_op_walk() can be cleaned up. Add some checks to callers of
gmap_pte_op_walk().
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20171110151805.7541-1-david@redhat.com>
Reviewed-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
This adds a memory barrier when performing a lookup into
the vmcs_field_to_offset_table. This is related to
CVE-2017-5753.
Signed-off-by: Andrew Honig <ahonig@google.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
After the vcpu_load/vcpu_put pushdown, the handling of asynchronous VCPU
ioctl is already much clearer in that it is obvious that they bypass
vcpu_load and vcpu_put.
However, it is still not perfect in that the different state of the VCPU
mutex is still hidden in the caller. Separate those ioctls into a new
function kvm_arch_vcpu_async_ioctl that returns -ENOIOCTLCMD for more
"traditional" synchronous ioctls.
Cc: James Hogan <jhogan@kernel.org>
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Suggested-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Move the calls to vcpu_load() and vcpu_put() in to the architecture
specific implementations of kvm_arch_vcpu_ioctl() which dispatches
further architecture-specific ioctls on to other functions.
Some architectures support asynchronous vcpu ioctls which cannot call
vcpu_load() or take the vcpu->mutex, because that would prevent
concurrent execution with a running VCPU, which is the intended purpose
of these ioctls, for example because they inject interrupts.
We repeat the separate checks for these specifics in the architecture
code for MIPS, S390 and PPC, and avoid taking the vcpu->mutex and
calling vcpu_load for these ioctls.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Move vcpu_load() and vcpu_put() into the architecture specific
implementations of kvm_arch_vcpu_ioctl_set_fpu().
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Move vcpu_load() and vcpu_put() into the architecture specific
implementations of kvm_arch_vcpu_ioctl_get_fpu().
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Move vcpu_load() and vcpu_put() into the architecture specific
implementations of kvm_arch_vcpu_ioctl_set_guest_debug().
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Move vcpu_load() and vcpu_put() into the architecture specific
implementations of kvm_arch_vcpu_ioctl_translate().
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Move vcpu_load() and vcpu_put() into the architecture specific
implementations of kvm_arch_vcpu_ioctl_set_mpstate().
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Move vcpu_load() and vcpu_put() into the architecture specific
implementations of kvm_arch_vcpu_ioctl_get_mpstate().
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Move vcpu_load() and vcpu_put() into the architecture specific
implementations of kvm_arch_vcpu_ioctl_set_sregs().
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Move vcpu_load() and vcpu_put() into the architecture specific
implementations of kvm_arch_vcpu_ioctl_get_sregs().
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Move vcpu_load() and vcpu_put() into the architecture specific
implementations of kvm_arch_vcpu_ioctl_set_regs().
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
