From c8848cee74ff05638e913582a476bde879c968ad Mon Sep 17 00:00:00 2001
From: Jan Dakinevich <jan.dakinevich@virtuozzo.com>
Date: Tue, 27 Aug 2019 13:07:08 +0000
Subject: [PATCH] KVM: x86: set ctxt->have_exception in x86_decode_insn()
x86_emulate_instruction() takes into account ctxt->have_exception flag
during instruction decoding, but in practice this flag is never set in
x86_decode_insn().
Fixes: 6ea6e84309ca ("KVM: x86: inject exceptions produced by x86_decode_insn")
Cc: stable@vger.kernel.org
Cc: Denis Lunev <den@virtuozzo.com>
Cc: Roman Kagan <rkagan@virtuozzo.com>
Cc: Denis Plotnikov <dplotnikov@virtuozzo.com>
Signed-off-by: Jan Dakinevich <jan.dakinevich@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/kvm/emulate.c | 2 ++
arch/x86/kvm/x86.c | 6 ++++++
2 files changed, 8 insertions(+)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index bef3c3c695d73..698efb8c38971 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -5416,6 +5416,8 @@ int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len)
ctxt->memopp->addr.mem.ea + ctxt->_eip);
done:
+ if (rc == X86EMUL_PROPAGATE_FAULT)
+ ctxt->have_exception = true;
return (rc != X86EMUL_CONTINUE) ? EMULATION_FAILED : EMULATION_OK;
}
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 263fac7e9307d..f7cfd8e6edd17 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6577,6 +6577,12 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu,
emulation_type))
return EMULATE_DONE;
if (ctxt->have_exception) {
+ /*
+ * #UD should result in just EMULATION_FAILED, and trap-like
+ * exception should not be encountered during decode.
+ */
+ WARN_ON_ONCE(ctxt->exception.vector == UD_VECTOR ||
+ exception_type(ctxt->exception.vector) == EXCPT_TRAP);
inject_emulated_exception(vcpu);
return EMULATE_DONE;
}
--
GitLab