[PATCH v2 25/43] KVM: VMX: Save/restore IRQs (instead of CLI/STI) during PI pre/post block

From: Sean Christopherson
Date: Fri Oct 08 2021 - 22:15:20 EST


Save/restore IRQs when disabling IRQs in posted interrupt pre/post block
in preparation for moving the code into vcpu_put/load(), and thus may be
called with IRQs already disabled.

No functional changed intended.

Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/vmx/posted_intr.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kvm/vmx/posted_intr.c b/arch/x86/kvm/vmx/posted_intr.c
index 239e0e72a0dd..414ea6972b5c 100644
--- a/arch/x86/kvm/vmx/posted_intr.c
+++ b/arch/x86/kvm/vmx/posted_intr.c
@@ -140,6 +140,7 @@ int pi_pre_block(struct kvm_vcpu *vcpu)
{
struct pi_desc old, new;
struct pi_desc *pi_desc = vcpu_to_pi_desc(vcpu);
+ unsigned long flags;

if (!kvm_arch_has_assigned_device(vcpu->kvm) ||
!irq_remapping_cap(IRQ_POSTING_CAP) ||
@@ -147,8 +148,7 @@ int pi_pre_block(struct kvm_vcpu *vcpu)
vmx_interrupt_blocked(vcpu))
return 0;

- WARN_ON(irqs_disabled());
- local_irq_disable();
+ local_irq_save(flags);

vcpu->pre_pcpu = vcpu->cpu;
spin_lock(&per_cpu(blocked_vcpu_on_cpu_lock, vcpu->cpu));
@@ -171,19 +171,20 @@ int pi_pre_block(struct kvm_vcpu *vcpu)
if (pi_test_on(pi_desc))
__pi_post_block(vcpu);

- local_irq_enable();
+ local_irq_restore(flags);
return (vcpu->pre_pcpu == -1);
}

void pi_post_block(struct kvm_vcpu *vcpu)
{
+ unsigned long flags;
+
if (vcpu->pre_pcpu == -1)
return;

- WARN_ON(irqs_disabled());
- local_irq_disable();
+ local_irq_save(flags);
__pi_post_block(vcpu);
- local_irq_enable();
+ local_irq_restore(flags);
}

/*
--
2.33.0.882.g93a45727a2-goog