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KVM: x86 emulator: fix access registers for instructions with ModR/M byte and Mod = 3

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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>
This commit is contained in:
Aurelien Jarno 2007-10-17 19:30:41 +02:00 committed by Avi Kivity
parent 78f7826868
commit 4e62417bf3
1 changed files with 16 additions and 0 deletions
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16
drivers/kvm/x86_emulate.c
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@ -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);