KVM: x86: leave vcpu->arch.pio.count alone in emulator_pio_in_out

Currently emulator_pio_in clears vcpu->arch.pio.count twice if
emulator_pio_in_out performs kernel PIO.  Move the clear into
emulator_pio_out where it is actually necessary.

No functional change intended.

Cc: stable@vger.kernel.org
Fixes: 7ed9abfe8e9f ("KVM: SVM: Support string IO operations for an SEV-ES guest")
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 379175b725a13a9da7998c9f2fda7f96824120cc..dff28a4fbb21c294a944777cc57f73c97f9f17a1 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6914,10 +6914,8 @@ static int emulator_pio_in_out(struct kvm_vcpu *vcpu, int size,
        vcpu->arch.pio.count  = count;
        vcpu->arch.pio.size = size;
 
-       if (!kernel_pio(vcpu, vcpu->arch.pio_data)) {
-               vcpu->arch.pio.count = 0;
+       if (!kernel_pio(vcpu, vcpu->arch.pio_data))
                return 1;
-       }
 
        vcpu->run->exit_reason = KVM_EXIT_IO;
        vcpu->run->io.direction = in ? KVM_EXIT_IO_IN : KVM_EXIT_IO_OUT;
@@ -6963,9 +6961,16 @@ static int emulator_pio_out(struct kvm_vcpu *vcpu, int size,
                            unsigned short port, const void *val,
                            unsigned int count)
 {
+       int ret;
+
        memcpy(vcpu->arch.pio_data, val, size * count);
        trace_kvm_pio(KVM_PIO_OUT, port, size, count, vcpu->arch.pio_data);
-       return emulator_pio_in_out(vcpu, size, port, (void *)val, count, false);
+       ret = emulator_pio_in_out(vcpu, size, port, (void *)val, count, false);
+       if (ret)
+                vcpu->arch.pio.count = 0;
+
+        return ret;
+
 }
 
 static int emulator_pio_out_emulated(struct x86_emulate_ctxt *ctxt,