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authorAvi Kivity <avi@qumranet.com>2008-05-05 14:58:26 +0300
committerAvi Kivity <avi@qumranet.com>2008-05-18 14:34:14 +0300
commit107d6d2efa9eb8c48d050936d8019230ac6b24cd (patch)
treefc1d94a18e3f909e31c900ac698811831ed0abb2 /arch/x86/kvm/x86_emulate.c
parentf26a3988917913b3d11b2bd741601a2c64ab9204 (diff)
KVM: x86 emulator: fix writes to registers with modrm encodings
A register destination encoded with a mod=3 encoding left dst.ptr NULL. Normally we don't trap writes to registers, but in the case of smsw, we do. Fix by pointing dst.ptr at the destination register. Signed-off-by: Avi Kivity <avi@qumranet.com>
Diffstat (limited to 'arch/x86/kvm/x86_emulate.c')
-rw-r--r--arch/x86/kvm/x86_emulate.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/arch/x86/kvm/x86_emulate.c b/arch/x86/kvm/x86_emulate.c
index f2a696d6a243..8a96320ab071 100644
--- a/arch/x86/kvm/x86_emulate.c
+++ b/arch/x86/kvm/x86_emulate.c
@@ -677,8 +677,9 @@ static int decode_modrm(struct x86_emulate_ctxt *ctxt,
c->use_modrm_ea = 1;
if (c->modrm_mod == 3) {
- c->modrm_val = *(unsigned long *)
- decode_register(c->modrm_rm, c->regs, c->d & ByteOp);
+ c->modrm_ptr = decode_register(c->modrm_rm,
+ c->regs, c->d & ByteOp);
+ c->modrm_val = *(unsigned long *)c->modrm_ptr;
return rc;
}
@@ -1005,6 +1006,7 @@ done_prefixes:
if ((c->d & ModRM) && c->modrm_mod == 3) {
c->src.type = OP_REG;
c->src.val = c->modrm_val;
+ c->src.ptr = c->modrm_ptr;
break;
}
c->src.type = OP_MEM;
@@ -1049,6 +1051,7 @@ done_prefixes:
if ((c->d & ModRM) && c->modrm_mod == 3) {
c->dst.type = OP_REG;
c->dst.val = c->dst.orig_val = c->modrm_val;
+ c->dst.ptr = c->modrm_ptr;
break;
}
c->dst.type = OP_MEM;