[PATCH 5.15 055/262] KVM: VMX: Dont unblock vCPU w/ Posted IRQ if IRQs are disabled in guest

[Greg Kroah-Hartman]

From: Paolo Bonzini <pbonzini@xxxxxxxxxx>

[ Upstream commit 1831fa44df743a7cdffdf1c12c799bf6f3c12b8c ]

Don't configure the wakeup handler when a vCPU is blocking with IRQs
disabled, in which case any IRQ, posted or otherwise, should not be
recognized and thus should not wake the vCPU.

Fixes: bf9f6ac8d749 ("KVM: Update Posted-Interrupts Descriptor when vCPU is blocked")
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Message-Id: <20211009021236.4122790-2-seanjc@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 arch/x86/kvm/vmx/posted_intr.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx/posted_intr.c b/arch/x86/kvm/vmx/posted_intr.c
index 21ea58d25771f..696ad48ab5daa 100644
--- a/arch/x86/kvm/vmx/posted_intr.c
+++ b/arch/x86/kvm/vmx/posted_intr.c
@@ -147,7 +147,8 @@ int pi_pre_block(struct kvm_vcpu *vcpu)
 	struct pi_desc old, new;
 	struct pi_desc *pi_desc = vcpu_to_pi_desc(vcpu);
 
-	if (!vmx_can_use_vtd_pi(vcpu->kvm))
+	if (!vmx_can_use_vtd_pi(vcpu->kvm) ||
+	    vmx_interrupt_blocked(vcpu))
 		return 0;
 
 	WARN_ON(irqs_disabled());
-- 
2.34.1