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author | Liran Alon <liran.alon@oracle.com> | 2018-09-04 10:56:52 +0300 |
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committer | Paolo Bonzini <pbonzini@redhat.com> | 2018-09-20 00:51:44 +0200 |
commit | e6c67d8cf1173b229f0c4343d1cc7925eca11c11 (patch) | |
tree | ac7d0b8e88cf0c9820b78440803bfab121bde538 /arch/x86/kvm/vmx.c | |
parent | KVM: VMX: check nested state and CR4.VMXE against SMM (diff) | |
download | linux-dev-e6c67d8cf1173b229f0c4343d1cc7925eca11c11.tar.xz linux-dev-e6c67d8cf1173b229f0c4343d1cc7925eca11c11.zip |
KVM: nVMX: Wake blocked vCPU in guest-mode if pending interrupt in virtual APICv
In case L1 do not intercept L2 HLT or enter L2 in HLT activity-state,
it is possible for a vCPU to be blocked while it is in guest-mode.
According to Intel SDM 26.6.5 Interrupt-Window Exiting and
Virtual-Interrupt Delivery: "These events wake the logical processor
if it just entered the HLT state because of a VM entry".
Therefore, if L1 enters L2 in HLT activity-state and L2 has a pending
deliverable interrupt in vmcs12->guest_intr_status.RVI, then the vCPU
should be waken from the HLT state and injected with the interrupt.
In addition, if while the vCPU is blocked (while it is in guest-mode),
it receives a nested posted-interrupt, then the vCPU should also be
waken and injected with the posted interrupt.
To handle these cases, this patch enhances kvm_vcpu_has_events() to also
check if there is a pending interrupt in L2 virtual APICv provided by
L1. That is, it evaluates if there is a pending virtual interrupt for L2
by checking RVI[7:4] > VPPR[7:4] as specified in Intel SDM 29.2.1
Evaluation of Pending Interrupts.
Note that this also handles the case of nested posted-interrupt by the
fact RVI is updated in vmx_complete_nested_posted_interrupt() which is
called from kvm_vcpu_check_block() -> kvm_arch_vcpu_runnable() ->
kvm_vcpu_running() -> vmx_check_nested_events() ->
vmx_complete_nested_posted_interrupt().
Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/vmx.c')
-rw-r--r-- | arch/x86/kvm/vmx.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 16e63a92992f..98b1203e8823 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -6189,6 +6189,27 @@ static void vmx_complete_nested_posted_interrupt(struct kvm_vcpu *vcpu) nested_mark_vmcs12_pages_dirty(vcpu); } +static bool vmx_guest_apic_has_interrupt(struct kvm_vcpu *vcpu) +{ + struct vcpu_vmx *vmx = to_vmx(vcpu); + void *vapic_page; + u32 vppr; + int rvi; + + if (WARN_ON_ONCE(!is_guest_mode(vcpu)) || + !nested_cpu_has_vid(get_vmcs12(vcpu)) || + WARN_ON_ONCE(!vmx->nested.virtual_apic_page)) + return false; + + rvi = vmcs_read16(GUEST_INTR_STATUS) & 0xff; + + vapic_page = kmap(vmx->nested.virtual_apic_page); + vppr = *((u32 *)(vapic_page + APIC_PROCPRI)); + kunmap(vmx->nested.virtual_apic_page); + + return ((rvi & 0xf0) > (vppr & 0xf0)); +} + static inline bool kvm_vcpu_trigger_posted_interrupt(struct kvm_vcpu *vcpu, bool nested) { @@ -14129,6 +14150,7 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = { .apicv_post_state_restore = vmx_apicv_post_state_restore, .hwapic_irr_update = vmx_hwapic_irr_update, .hwapic_isr_update = vmx_hwapic_isr_update, + .guest_apic_has_interrupt = vmx_guest_apic_has_interrupt, .sync_pir_to_irr = vmx_sync_pir_to_irr, .deliver_posted_interrupt = vmx_deliver_posted_interrupt, |