KVM: VMX: Don't unblock vCPU w/ Posted IRQ if IRQs are disabled in guest

BugLink: https://bugs.launchpad.net/bugs/1964361
[ 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@google.com>
Message-Id: <20211009021236.4122790-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>

diff --git a/arch/x86/kvm/vmx/posted_intr.c b/arch/x86/kvm/vmx/posted_intr.c
index 21ea58d25771f6e35646edd7cf3549c6cb204646..696ad48ab5daad995231bcd71b30dea3620403f1 100644 (file)
--- 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());