[PATCH 1/8] KVM: SEV-ES: fix length of string I/O

From: Paolo Bonzini
Date: Wed Oct 13 2021 - 12:56:32 EST


The size of the data in the scratch buffer is not divided by the size of
each port I/O operation, so vcpu->arch.pio.count ends up being larger
than it should be by a factor of size.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: 7ed9abfe8e9f ("KVM: SVM: Support string IO operations for an SEV-ES guest")
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/kvm/svm/sev.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index c36b5fe4c27c..e672493b5d8d 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -2583,7 +2583,7 @@ int sev_es_string_io(struct vcpu_svm *svm, int size, unsigned int port, int in)
return -EINVAL;

return kvm_sev_es_string_io(&svm->vcpu, size, port,
- svm->ghcb_sa, svm->ghcb_sa_len, in);
+ svm->ghcb_sa, svm->ghcb_sa_len / size, in);
}

void sev_es_init_vmcb(struct vcpu_svm *svm)
--
2.27.0