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[05/15] KVM: x86 emulator: Add flag to check for protected mode instructions

Message ID 1301913576-10360-6-git-send-email-joerg.roedel@amd.com (mailing list archive)
State New, archived
Headers show

Commit Message

Joerg Roedel April 4, 2011, 10:39 a.m. UTC 
This patch adds a flag for the opcoded to tag instruction
which are only recognized in protected mode. The necessary
check is added too.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
---
 arch/x86/include/asm/kvm_emulate.h |    4 ++++
 arch/x86/kvm/emulate.c             |    7 +++++++
 2 files changed, 11 insertions(+), 0 deletions(-)
diff mbox

Patch

diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h
index a891051..dfca25b 100644
--- a/arch/x86/include/asm/kvm_emulate.h
+++ b/arch/x86/include/asm/kvm_emulate.h
@@ -268,6 +268,10 @@  struct x86_emulate_ctxt {
 #define X86EMUL_MODE_PROT32   4	/* 32-bit protected mode. */
 #define X86EMUL_MODE_PROT64   8	/* 64-bit (long) mode.    */
 
+/* any protected mode   */
+#define X86EMUL_MODE_PROT     (X86EMUL_MODE_PROT16|X86EMUL_MODE_PROT32| \
+			       X86EMUL_MODE_PROT64)
+
 enum x86_intercept_stage {
 	X86_ICPT_PRE_EXCEPT,
 	X86_ICPT_POST_EXCEPT,
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index b002845..686fa0b 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -76,6 +76,7 @@ 
 #define Group       (1<<14)     /* Bits 3:5 of modrm byte extend opcode */
 #define GroupDual   (1<<15)     /* Alternate decoding of mod == 3 */
 /* Misc flags */
+#define Prot        (1<<21) /* instruction generates #UD if not in prot-mode */
 #define VendorSpecific (1<<22) /* Vendor specific instruction */
 #define NoAccess    (1<<23) /* Don't access memory (lea/invlpg/verr etc) */
 #define Op3264      (1<<24) /* Operand is 64b in long mode, 32b otherwise */
@@ -3008,6 +3009,12 @@  x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
 		goto done;
 	}
 
+	/* Instruction can only be executed in protected mode */
+	if ((c->d & Prot) && !(ctxt->mode & X86EMUL_MODE_PROT)) {
+		rc = emulate_ud(ctxt);
+		goto done;
+	}
+
 	/* Do instruction specific permission checks */
 	if (c->check_perm) {
 		rc = c->check_perm(ctxt);