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authorAurelien Jarno <aurelien@aurel32.net>2007-10-17 19:30:41 +0200
committerAvi Kivity <avi@qumranet.com>2007-10-22 12:03:29 +0200
commit4e62417bf317504c0b85e0d7abd236f334f54eaf (patch)
tree67d1716640ca88c0b67dda3831e30efc0f0a0c06 /drivers/kvm
parent78f7826868da8e27d097802139a3fec39f47f3b8 (diff)
KVM: x86 emulator: fix access registers for instructions with ModR/M byte and Mod = 3
The patch belows changes the access type to register from memory for instructions that are declared as SrcMem or DstMem, but have a ModR/M byte with Mod = 3. It fixes (at least) the lmsw and smsw instructions on an AMD64 CPU, which are needed for FreeBSD. Signed-off-by: Aurelien Jarno <aurelien@aurel32.net> Signed-off-by: Avi Kivity <avi@qumranet.com>
Diffstat (limited to 'drivers/kvm')
-rw-r--r--drivers/kvm/x86_emulate.c16
1 files changed, 16 insertions, 0 deletions
diff --git a/drivers/kvm/x86_emulate.c b/drivers/kvm/x86_emulate.c
index 0a8696d9b82..a6ace302e0c 100644
--- a/drivers/kvm/x86_emulate.c
+++ b/drivers/kvm/x86_emulate.c
@@ -825,6 +825,14 @@ done_prefixes:
if (twobyte && b == 0x01 && modrm_reg == 7)
break;
srcmem_common:
+ /*
+ * For instructions with a ModR/M byte, switch to register
+ * access if Mod = 3.
+ */
+ if ((d & ModRM) && modrm_mod == 3) {
+ src.type = OP_REG;
+ break;
+ }
src.type = OP_MEM;
src.ptr = (unsigned long *)cr2;
src.val = 0;
@@ -893,6 +901,14 @@ done_prefixes:
dst.ptr = (unsigned long *)cr2;
dst.bytes = (d & ByteOp) ? 1 : op_bytes;
dst.val = 0;
+ /*
+ * For instructions with a ModR/M byte, switch to register
+ * access if Mod = 3.
+ */
+ if ((d & ModRM) && modrm_mod == 3) {
+ dst.type = OP_REG;
+ break;
+ }
if (d & BitOp) {
unsigned long mask = ~(dst.bytes * 8 - 1);