vmx_check_nested_events() should return -EBUSY only in case there is a
pending L1 event which requires a VMExit from L2 to L1 but such a
VMExit is currently blocked. Such VMExits are blocked either
because nested_run_pending=1 or an event was reinjected to L2.
vmx_check_nested_events() should return 0 in case there are no
pending L1 events which requires a VMExit from L2 to L1 or if
a VMExit from L2 to L1 was done internally.
However, upstream commit which introduced blocking in case an event was
reinjected to L2 (commit acc9ab601327 ("KVM: nVMX: Fix pending events
injection")) contains a bug: It returns -EBUSY even if there are no
pending L1 events which requires VMExit from L2 to L1.
This commit fix this issue.
Fixes: acc9ab601327 ("KVM: nVMX: Fix pending events injection")
Signed-off-by: Liran Alon <liran.alon@xxxxxxxxxx>
Reviewed-by: Nikita Leshenko <nikita.leshchenko@xxxxxxxxxx>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
---
arch/x86/kvm/vmx.c | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 95a01609d7ee..ec3bf833a1bc 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -11034,13 +11034,12 @@ static int vmx_check_nested_events(struct kvm_vcpu *vcpu, bool external_intr)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
unsigned long exit_qual;
-
- if (kvm_event_needs_reinjection(vcpu))
- return -EBUSY;
+ bool block_nested_events =
+ vmx->nested.nested_run_pending || kvm_event_needs_reinjection(vcpu);
if (vcpu->arch.exception.pending &&
nested_vmx_check_exception(vcpu, &exit_qual)) {
- if (vmx->nested.nested_run_pending)
+ if (block_nested_events)
return -EBUSY;
nested_vmx_inject_exception_vmexit(vcpu, exit_qual);
vcpu->arch.exception.pending = false;
@@ -11049,14 +11048,14 @@ static int vmx_check_nested_events(struct kvm_vcpu *vcpu, bool external_intr)
if (nested_cpu_has_preemption_timer(get_vmcs12(vcpu)) &&
vmx->nested.preemption_timer_expired) {
- if (vmx->nested.nested_run_pending)
+ if (block_nested_events)
return -EBUSY;
nested_vmx_vmexit(vcpu, EXIT_REASON_PREEMPTION_TIMER, 0, 0);
return 0;
}
if (vcpu->arch.nmi_pending && nested_exit_on_nmi(vcpu)) {
- if (vmx->nested.nested_run_pending)
+ if (block_nested_events)
return -EBUSY;
nested_vmx_vmexit(vcpu, EXIT_REASON_EXCEPTION_NMI,
NMI_VECTOR | INTR_TYPE_NMI_INTR |
@@ -11072,7 +11071,7 @@ static int vmx_check_nested_events(struct kvm_vcpu *vcpu, bool external_intr)
if ((kvm_cpu_has_interrupt(vcpu) || external_intr) &&
nested_exit_on_intr(vcpu)) {
- if (vmx->nested.nested_run_pending)
+ if (block_nested_events)
return -EBUSY;
nested_vmx_vmexit(vcpu, EXIT_REASON_EXTERNAL_INTERRUPT, 0, 0);
return 0;
--
1.9.1
