KVM: x86 emulator: Add support for mov seg, r (0x8e) instruction

Add support for mov r, sreg (0x8c) instruction.

[avi: drop the sreg decoding table in favor of 1:1 encoding]

Signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: Laurent Vivier <laurent.vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>

diff --git a/arch/x86/kvm/x86_emulate.c b/arch/x86/kvm/x86_emulate.c
index 21d7ff6..b049b6b 100644 (file)
--- a/arch/x86/kvm/x86_emulate.c
+++ b/arch/x86/kvm/x86_emulate.c
@@ -138,7 +138,8 @@ static u16 opcode_table[256] = {
        /* 0x88 - 0x8F */
        ByteOp | DstMem | SrcReg | ModRM | Mov, DstMem | SrcReg | ModRM | Mov,
        ByteOp | DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov,
-       0, ModRM | DstReg, 0, Group | Group1A,
+       0, ModRM | DstReg,
+       DstReg | SrcMem | ModRM | Mov, Group | Group1A,
        /* 0x90 - 0x9F */
        0, 0, 0, 0, 0, 0, 0, 0,
        0, 0, 0, 0, ImplicitOps | Stack, ImplicitOps | Stack, 0, 0,
@@ -1520,6 +1521,28 @@ special_insn:
        case 0x8d: /* lea r16/r32, m */
                c->dst.val = c->modrm_ea;
                break;
+       case 0x8e: { /* mov seg, r/m16 */
+               uint16_t sel;
+               int type_bits;
+               int err;
+
+               sel = c->src.val;
+               if (c->modrm_reg <= 5) {
+                       type_bits = (c->modrm_reg == 1) ? 9 : 1;
+                       err = kvm_load_segment_descriptor(ctxt->vcpu, sel,
+                                                         type_bits, c->modrm_reg);
+               } else {
+                       printk(KERN_INFO "Invalid segreg in modrm byte 0x%02x\n",
+                                       c->modrm);
+                       goto cannot_emulate;
+               }
+
+               if (err < 0)
+                       goto cannot_emulate;
+
+               c->dst.type = OP_NONE;  /* Disable writeback. */
+               break;
+       }
        case 0x8f:              /* pop (sole member of Grp1a) */
                rc = emulate_grp1a(ctxt, ops);
                if (rc != 0)