From 169577c8840e4da46eac5823fba76899294ac562 Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini@redhat.com>
Date: Wed, 13 Oct 2021 12:29:42 -0400
Subject: [PATCH] KVM: x86: leave vcpu->arch.pio.count alone in emulator_pio_in_out
Git-commit: 0d33b1baeb6ca7165d5ed4fdd1a8f969985e35b9
Patch-mainline: v5.15-rc7
References: stable-5.14.15
commit 0d33b1baeb6ca7165d5ed4fdd1a8f969985e35b9 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
arch/x86/kvm/x86.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 84de77cc6452..244eaa33a1d0 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6915,10 +6915,8 @@ 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;
@@ -6964,9 +6962,16 @@ 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,
--
2.26.2