[PATCH] Revert "KVM: x86: Unconditionally enable irqs in guest context"

[Nitesh Narayan Lal]

This reverts commit d7a08882a0a4b4e176691331ee3f492996579534.

After the introduction of the patch:

        87fa7f3e9: x86/kvm: Move context tracking where it belongs

since we have moved guest_exit_irqoff closer to the VM-Exit, explicit
enabling of irqs to process pending interrupts should not be required
within vcpu_enter_guest anymore.

Conflicts:
        arch/x86/kvm/svm.c

Signed-off-by: Nitesh Narayan Lal <nit...@redhat.com>
---
 arch/x86/kvm/svm/svm.c |  9 +++++++++
 arch/x86/kvm/x86.c     | 11 -----------
 2 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index cce0143a6f80..c9b2fbb32484 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4187,6 +4187,15 @@ static int svm_check_intercept(struct kvm_vcpu *vcpu,
 
 static void svm_handle_exit_irqoff(struct kvm_vcpu *vcpu)
 {
+       kvm_before_interrupt(vcpu);
+       local_irq_enable();
+       /*
+        * We must have an instruction with interrupts enabled, so
+        * the timer interrupt isn't delayed by the interrupt shadow.
+        */
+       asm("nop");
+       local_irq_disable();
+       kvm_after_interrupt(vcpu);
 }
 
 static void svm_sched_in(struct kvm_vcpu *vcpu, int cpu)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 3f7c1fc7a3ce..3e17c9ffcad8 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9023,18 +9023,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
 
        kvm_x86_ops.handle_exit_irqoff(vcpu);
 
-       /*
-        * Consume any pending interrupts, including the possible source of
-        * VM-Exit on SVM and any ticks that occur between VM-Exit and now.
-        * An instruction is required after local_irq_enable() to fully unblock
-        * interrupts on processors that implement an interrupt shadow, the
-        * stat.exits increment will do nicely.
-        */
-       kvm_before_interrupt(vcpu);
-       local_irq_enable();
        ++vcpu->stat.exits;
-       local_irq_disable();
-       kvm_after_interrupt(vcpu);
 
        if (lapic_in_kernel(vcpu)) {
                s64 delta = vcpu->arch.apic->lapic_timer.advance_expire_delta;
-- 
2.27.0