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authorLiran Alon <liran.alon@oracle.com>2018-09-04 09:56:52 +0200
committerPaolo Bonzini <pbonzini@redhat.com>2018-09-20 00:51:44 +0200
commite6c67d8cf1173b229f0c4343d1cc7925eca11c11 (patch)
treeac7d0b8e88cf0c9820b78440803bfab121bde538 /arch/x86/kvm/x86.c
parentKVM: VMX: check nested state and CR4.VMXE against SMM (diff)
downloadlinux-e6c67d8cf1173b229f0c4343d1cc7925eca11c11.tar.xz
linux-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 '')
-rw-r--r--arch/x86/kvm/x86.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 6f4789398876..5fea53cdc583 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9206,6 +9206,13 @@ void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
kvm_page_track_flush_slot(kvm, slot);
}
+static inline bool kvm_guest_apic_has_interrupt(struct kvm_vcpu *vcpu)
+{
+ return (is_guest_mode(vcpu) &&
+ kvm_x86_ops->guest_apic_has_interrupt &&
+ kvm_x86_ops->guest_apic_has_interrupt(vcpu));
+}
+
static inline bool kvm_vcpu_has_events(struct kvm_vcpu *vcpu)
{
if (!list_empty_careful(&vcpu->async_pf.done))
@@ -9230,7 +9237,8 @@ static inline bool kvm_vcpu_has_events(struct kvm_vcpu *vcpu)
return true;
if (kvm_arch_interrupt_allowed(vcpu) &&
- kvm_cpu_has_interrupt(vcpu))
+ (kvm_cpu_has_interrupt(vcpu) ||
+ kvm_guest_apic_has_interrupt(vcpu)))
return true;
if (kvm_hv_has_stimer_pending(vcpu))