KVM: Implement emulation of "pop reg" instruction (opcode 0x58-0x5f)

For use in real mode.

Signed-off-by: Nitin A Kamble <nitin.a.kamble@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 15 insertions, 2 deletions

diff --git a/drivers/kvm/x86_emulate.c b/drivers/kvm/x86_emulate.c
index a4a84817b274..46c38063a102 100644
--- a/drivers/kvm/x86_emulate.c
+++ b/drivers/kvm/x86_emulate.c
@@ -98,8 +98,11 @@ static u8 opcode_table[256] = {
         0, 0, 0, 0,
         /* 0x40 - 0x4F */
         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-        /* 0x50 - 0x5F */
-        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+        /* 0x50 - 0x57 */
+        0, 0, 0, 0, 0, 0, 0, 0,
+        /* 0x58 - 0x5F */
+        ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps,
+        ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps,
         /* 0x60 - 0x6F */
         0, 0, 0, DstReg | SrcMem32 | ModRM | Mov /* movsxd (x86/64) */ ,
         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
@@ -1153,6 +1156,16 @@ special_insn:
         case 0xf4:              /* hlt */
                 ctxt->vcpu->halt_request = 1;
                 goto done;
+        case 0x58 ... 0x5f: /* pop reg */
+                dst.ptr = (unsigned long *)&_regs[b & 0x7];
+
+                if ((rc = ops->read_std(register_address(ctxt->ss_base,
+                        _regs[VCPU_REGS_RSP]), dst.ptr, op_bytes, ctxt)) != 0)
+                        goto done;
+
+                register_address_increment(_regs[VCPU_REGS_RSP], dst.bytes);
+                dst.orig_val = dst.val; /* Disable writeback. */
+                break;
         }
         goto writeback;