linux-kernel - [PATCH 7/9] KVM: SVM: Add intercept checks for one-byte instructions

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Date:	Wed, 24 Nov 2010 19:18:33 +0100
From:	Joerg Roedel <joerg.roedel@....com>
To:	Avi Kivity <avi@...hat.com>, Marcelo Tosatti <mtosatti@...hat.com>
CC:	<kvm@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
	Joerg Roedel <joerg.roedel@....com>
Subject: [PATCH 7/9] KVM: SVM: Add intercept checks for one-byte instructions

This patch add intercept checks for emulated one-byte
instructions to the KVM instruction emulation path.

Signed-off-by: Joerg Roedel <joerg.roedel@....com>
---
 arch/x86/kvm/svm.c |   36 +++++++++++++++++++++++++++++++++---
 1 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 77b344e..2a30b5b 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -3668,6 +3668,35 @@ static void svm_check_group7(struct vmcb *vmcb, struct x86_emulate_ctxt *ctxt)
 	}
 }
 
+static void svm_check_onebyte(struct vmcb *vmcb, struct x86_emulate_ctxt *ctxt)
+{
+	struct decode_cache *c = &ctxt->decode;
+
+	switch (c->b) {
+	case 0x90: /* PAUSE */
+		if (c->rep_prefix == REPE_PREFIX)
+			vmcb->control.exit_code = SVM_EXIT_PAUSE;
+		break;
+	case 0x9c: /* PUSHF */
+		break;
+	case 0x9d: /* POPF */
+		vmcb->control.exit_code = SVM_EXIT_POPF;
+		break;
+	case 0xcd: /* INTn */
+		vmcb->control.exit_code = SVM_EXIT_SWINT;
+		break;
+	case 0xcf: /* IRET */
+		vmcb->control.exit_code = SVM_EXIT_IRET;
+		break;
+	case 0xf1: /* ICEBP */
+		vmcb->control.exit_code = SVM_EXIT_ICEBP;
+		break;
+	case 0xf4: /* HLT */
+		vmcb->control.exit_code = SVM_EXIT_HLT;
+		break;
+	}
+}
+
 static int svm_insn_intercepted(struct kvm_vcpu *vcpu,
 				struct x86_emulate_ctxt *ctxt)
 {
@@ -3681,8 +3710,10 @@ static int svm_insn_intercepted(struct kvm_vcpu *vcpu,
 
 	ret = X86EMUL_CONTINUE;
 
-	if (!c->twobyte)
+	if (!c->twobyte) {
+		svm_check_onebyte(vmcb, ctxt);
 		goto out;
+	}
 
 	switch (c->b) {
 	case 0x00:
@@ -3799,14 +3830,13 @@ static int svm_insn_intercepted(struct kvm_vcpu *vcpu,
 		break;
 	}
 
+out:
 	vmcb->control.next_rip = ctxt->eip;
 	vmexit = nested_svm_exit_handled(svm);
 
 	ret = (vmexit == NESTED_EXIT_DONE) ? X86EMUL_INTERCEPTED
 					   : X86EMUL_CONTINUE;
 
-out:
-
 	return ret;
 }
 
-- 
1.7.1


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