KVM: x86 emulator: Add decoding of 16bit second in memory argument

Add decoding of Ep type of argument used by callf/jmpf.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index c9f604b0819c..97a740368b30 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -85,6 +85,9 @@
 #define Src2ImmByte (2<<29)
 #define Src2One     (3<<29)
 #define Src2Imm16   (4<<29)
+#define Src2Mem16   (5<<29) /* Used for Ep encoding. First argument has to be
+                               in memory and second argument is located
+                               immediately after the first one in memory. */
 #define Src2Mask    (7<<29)
 
 enum {
@@ -1163,6 +1166,10 @@ done_prefixes:
                 c->src2.bytes = 1;
                 c->src2.val = 1;
                 break;
+        case Src2Mem16:
+                c->src2.bytes = 2;
+                c->src2.type = OP_MEM;
+                break;
         }
 
         /* Decode and fetch the destination operand: register or memory. */
@@ -1881,6 +1888,17 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
                 c->src.orig_val = c->src.val;
         }
 
+        if (c->src2.type == OP_MEM) {
+                c->src2.ptr = (unsigned long *)(memop + c->src.bytes);
+                c->src2.val = 0;
+                rc = ops->read_emulated((unsigned long)c->src2.ptr,
+                                        &c->src2.val,
+                                        c->src2.bytes,
+                                        ctxt->vcpu);
+                if (rc != X86EMUL_CONTINUE)
+                        goto done;
+        }
+
         if ((c->d & DstMask) == ImplicitOps)
                 goto special_insn;