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From:   Paolo Bonzini <pbonzini@redhat.com>
To:     linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc:     fwilhelm@google.com, seanjc@google.com, oupton@google.com,
        stable@vger.kernel.org
Subject: [PATCH 1/8] KVM: SEV-ES: fix length of string I/O
Date:   Wed, 13 Oct 2021 12:56:09 -0400
Message-Id: <20211013165616.19846-2-pbonzini@redhat.com>
In-Reply-To: <20211013165616.19846-1-pbonzini@redhat.com>
References: <20211013165616.19846-1-pbonzini@redhat.com>
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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@vger.kernel.org
Fixes: 7ed9abfe8e9f ("KVM: SVM: Support string IO operations for an SEV-ES guest")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 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