Explicitly set posted_intr_nv to -1 when emulating nested VM-Enter and
posted interrupts are disabled to make it clear that posted_intr_nv is
valid if and only if nested posted interrupts are enabled, and as a cheap
way to harden against KVM bugs.
Note, KVM initializes posted_intr_nv to -1 at vCPU creation and when
resets it to -1 when unloading vmcs12 and/or leaving nested mode, i.e.
this is not a bug fix (or at least, it's not intended to be a bug fix).
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/vmx/nested.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 7e0a944088eb..40cf4839ca47 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -2317,10 +2317,12 @@ static void prepare_vmcs02_early(struct vcpu_vmx *vmx, struct loaded_vmcs *vmcs0
/* Posted interrupts setting is only taken from vmcs12. */
vmx->nested.pi_pending = false;
- if (nested_cpu_has_posted_intr(vmcs12))
+ if (nested_cpu_has_posted_intr(vmcs12)) {
vmx->nested.posted_intr_nv = vmcs12->posted_intr_nv;
- else
+ } else {
+ vmx->nested.posted_intr_nv = -1;
exec_control &= ~PIN_BASED_POSTED_INTR;
+ }
pin_controls_set(vmx, exec_control);
/*
--
2.45.2.1089.g2a221341d9-goog
