KVM: x86 emulator: Prepare for emulation of syscall instructions

Add the flags needed for syscall, sysenter and sysexit to the opcode table.
Catch (but for now ignore) the opcodes in the emulation switch/case.

Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Christoph Egger <christoph.egger@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 15 insertions, 2 deletions

diff --git a/arch/x86/kvm/x86_emulate.c b/arch/x86/kvm/x86_emulate.c
index 67af33aeb3f3..b0da29d74032 100644
--- a/arch/x86/kvm/x86_emulate.c
+++ b/arch/x86/kvm/x86_emulate.c
@@ -32,6 +32,8 @@
 #include <linux/module.h>
 #include <asm/kvm_x86_emulate.h>
 
+#include "mmu.h"                /* for is_long_mode() */
+
 /*
  * Opcode effective-address decode tables.
  * Note that we only emulate instructions that have at least one memory
@@ -209,7 +211,7 @@ static u32 opcode_table[256] = {
 
 static u32 twobyte_table[256] = {
         /* 0x00 - 0x0F */
-        0, Group | GroupDual | Group7, 0, 0, 0, 0, ImplicitOps, 0,
+        0, Group | GroupDual | Group7, 0, 0, 0, ImplicitOps, ImplicitOps, 0,
         ImplicitOps, ImplicitOps, 0, 0, 0, ImplicitOps | ModRM, 0, 0,
         /* 0x10 - 0x1F */
         0, 0, 0, 0, 0, 0, 0, 0, ImplicitOps | ModRM, 0, 0, 0, 0, 0, 0, 0,
@@ -217,7 +219,9 @@ static u32 twobyte_table[256] = {
         ModRM | ImplicitOps, ModRM, ModRM | ImplicitOps, ModRM, 0, 0, 0, 0,
         0, 0, 0, 0, 0, 0, 0, 0,
         /* 0x30 - 0x3F */
-        ImplicitOps, 0, ImplicitOps, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+        ImplicitOps, 0, ImplicitOps, 0,
+        ImplicitOps, ImplicitOps, 0, 0,
+        0, 0, 0, 0, 0, 0, 0, 0,
         /* 0x40 - 0x47 */
         DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov,
         DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov,
@@ -1988,6 +1992,9 @@ twobyte_insn:
                         goto cannot_emulate;
                 }
                 break;
+        case 0x05:              /* syscall */
+                goto cannot_emulate;
+                break;
         case 0x06:
                 emulate_clts(ctxt->vcpu);
                 c->dst.type = OP_NONE;
@@ -2054,6 +2061,12 @@ twobyte_insn:
                 rc = X86EMUL_CONTINUE;
                 c->dst.type = OP_NONE;
                 break;
+        case 0x34:              /* sysenter */
+                goto cannot_emulate;
+                break;
+        case 0x35:              /* sysexit */
+                goto cannot_emulate;
+                break;
         case 0x40 ... 0x4f:     /* cmov */
                 c->dst.val = c->dst.orig_val = c->src.val;
                 if (!test_cc(c->b, ctxt->eflags))