linux_dsm_epyc7002/arch/x86/kvm/vmx
Paolo Bonzini c9d40913ac KVM: x86: enable event window in inject_pending_event
In case an interrupt arrives after nested.check_events but before the
call to kvm_cpu_has_injectable_intr, we could end up enabling the interrupt
window even if the interrupt is actually going to be a vmexit.  This is
useless rather than harmful, but it really complicates reasoning about
SVM's handling of the VINTR intercept.  We'd like to never bother with
the VINTR intercept if V_INTR_MASKING=1 && INTERCEPT_INTR=1, because in
that case there is no interrupt window and we can just exit the nested
guest whenever we want.

This patch moves the opening of the interrupt window inside
inject_pending_event.  This consolidates the check for pending
interrupt/NMI/SMI in one place, and makes KVM's usage of immediate
exits more consistent, extending it beyond just nested virtualization.

There are two functional changes here.  They only affect corner cases,
but overall they simplify the inject_pending_event.

- re-injection of still-pending events will also use req_immediate_exit
instead of using interrupt-window intercepts.  This should have no impact
on performance on Intel since it simply replaces an interrupt-window
or NMI-window exit for a preemption-timer exit.  On AMD, which has no
equivalent of the preemption time, it may incur some overhead but an
actual effect on performance should only be visible in pathological cases.

- kvm_arch_interrupt_allowed and kvm_vcpu_has_events will return true
if an interrupt, NMI or SMI is blocked by nested_run_pending.  This
makes sense because entering the VM will allow it to make progress
and deliver the event.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-05-28 11:41:46 -04:00
..
capabilities.h KVM: x86: Handle PKU CPUID adjustment in VMX code 2020-03-16 17:58:19 +01:00
evmcs.c KVM: eVMCS: check if nesting is enabled 2020-04-23 09:04:56 -04:00
evmcs.h KVM: nVMX: properly handle errors in nested_vmx_handle_enlightened_vmptrld() 2020-03-16 18:19:30 +01:00
nested.c KVM: nVMX: Change emulated VMX-preemption timer hrtimer to absolute 2020-05-15 12:26:25 -04:00
nested.h KVM: nVMX: Remove unused 'ops' param from nested_vmx_hardware_setup() 2020-05-15 12:26:24 -04:00
ops.h KVM: VMX: Drop redundant capability checks in low level INVVPID helpers 2020-04-20 17:26:08 -04:00
pmu_intel.c KVM: VMX: Directly query Intel PT mode when refreshing PMUs 2020-03-16 17:58:38 +01:00
vmcs12.c KVM: nVMX: Remove non-functional "support" for CR3 target values 2020-04-21 09:13:09 -04:00
vmcs12.h KVM: nVMX: Remove non-functional "support" for CR3 target values 2020-04-21 09:13:09 -04:00
vmcs_shadow_fields.h KVM: Fix some out-dated function names in comment 2020-01-21 13:57:27 +01:00
vmcs.h KVM: VMX: Leave preemption timer running when it's disabled 2019-06-18 17:10:46 +02:00
vmenter.S KVM: VMX: Remove unneeded __ASM_SIZE usage with POP instruction 2020-05-15 12:26:13 -04:00
vmx.c KVM: x86: enable event window in inject_pending_event 2020-05-28 11:41:46 -04:00
vmx.h KVM: VMX: Add proper cache tracking for CR0 2020-05-13 12:15:12 -04:00