diff options
| author | Liran Alon <liran.alon@oracle.com> | 2017-12-24 18:12:55 +0200 |
|---|---|---|
| committer | Radim Krčmář <rkrcmar@redhat.com> | 2018-01-16 16:40:09 +0100 |
| commit | f27a85c4988d408a2918a3bcbc3d7fe4fb2dc2b3 (patch) | |
| tree | 6783014be25e51b83b6e66e22475b7574585f1e1 /arch/x86/kvm/vmx.c | |
| parent | e7387b0e27ec3a203bda4910dc4a107f6c5f912f (diff) | |
KVM: nVMX: Re-evaluate L1 pending events when running L2 and L1 got posted-interrupt
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>
Diffstat (limited to 'arch/x86/kvm/vmx.c')
| -rw-r--r-- | arch/x86/kvm/vmx.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 5ea482bb1b9c..5fe94e375d2d 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -8978,6 +8978,7 @@ static int vmx_sync_pir_to_irr(struct kvm_vcpu *vcpu) { struct vcpu_vmx *vmx = to_vmx(vcpu); int max_irr; + bool max_irr_updated; WARN_ON(!vcpu->arch.apicv_active); if (pi_test_on(&vmx->pi_desc)) { @@ -8987,7 +8988,16 @@ static int vmx_sync_pir_to_irr(struct kvm_vcpu *vcpu) * But on x86 this is just a compiler barrier anyway. */ smp_mb__after_atomic(); - kvm_apic_update_irr(vcpu, vmx->pi_desc.pir, &max_irr); + max_irr_updated = + kvm_apic_update_irr(vcpu, vmx->pi_desc.pir, &max_irr); + + /* + * If we are running L2 and L1 has a new pending interrupt + * which can be injected, we should re-evaluate + * what should be done with this new L1 interrupt. + */ + if (is_guest_mode(vcpu) && max_irr_updated) + kvm_vcpu_exiting_guest_mode(vcpu); } else { max_irr = kvm_lapic_find_highest_irr(vcpu); } |