Messages in this thread Patch in this message | | | From | Avi Kivity <> | Subject | [PATCH 02/10] KVM: x86 emulator: fix access registers for instructions with ModR/M byte and Mod = 3 | Date | Sun, 2 Dec 2007 13:18:39 +0200 |
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From: Aurelien Jarno <aurelien@aurel32.net>
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> --- drivers/kvm/x86_emulate.c | 17 +++++++++++++++++ 1 files changed, 17 insertions(+), 0 deletions(-)
diff --git a/drivers/kvm/x86_emulate.c b/drivers/kvm/x86_emulate.c index 804e86c..08cd4a3 100644 --- a/drivers/kvm/x86_emulate.c +++ b/drivers/kvm/x86_emulate.c @@ -773,6 +773,14 @@ done_prefixes: case SrcMem: src.bytes = (d & ByteOp) ? 1 : op_bytes; 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; if ((rc = ops->read_emulated((unsigned long)src.ptr, @@ -839,6 +847,15 @@ done_prefixes: dst.type = OP_MEM; 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); -- 1.5.3
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