KVM: x86: Dirty the dest op page on cmpxchg emulation

[linux.git] / arch / x86 / kvm / emulate.c

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index ef23c1e5fa9fb42442e6e2a53c7567594789fbb8..aa272545402ecad0384bbb7db9686f13ca62e217 100644 (file)
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -2205,12 +2205,15 @@ static int em_cmpxchg(struct x86_emulate_ctxt *ctxt)
        fastop(ctxt, em_cmp);
 
        if (ctxt->eflags & EFLG_ZF) {
-               /* Success: write back to memory. */
+               /* Success: write back to memory; no update of EAX */
+               ctxt->src.type = OP_NONE;
                ctxt->dst.val = ctxt->src.orig_val;
        } else {
                /* Failure: write the value we saw to EAX. */
-               ctxt->dst.type = OP_REG;
-               ctxt->dst.addr.reg = reg_rmw(ctxt, VCPU_REGS_RAX);
+               ctxt->src.type = OP_REG;
+               ctxt->src.addr.reg = reg_rmw(ctxt, VCPU_REGS_RAX);
+               ctxt->src.val = ctxt->dst.orig_val;
+               /* Create write-cycle to dest by writing the same value */
                ctxt->dst.val = ctxt->dst.orig_val;
        }
        return X86EMUL_CONTINUE;
@@ -4157,7 +4160,7 @@ static const struct opcode twobyte_table[256] = {
        F(DstMem | SrcReg | Src2CL | ModRM, em_shrd),
        GD(0, &group15), F(DstReg | SrcMem | ModRM, em_imul),
        /* 0xB0 - 0xB7 */
-       I2bv(DstMem | SrcReg | ModRM | Lock | PageTable, em_cmpxchg),
+       I2bv(DstMem | SrcReg | ModRM | Lock | PageTable | SrcWrite, em_cmpxchg),
        I(DstReg | SrcMemFAddr | ModRM | Src2SS, em_lseg),
        F(DstMem | SrcReg | ModRM | BitOp | Lock, em_btr),
        I(DstReg | SrcMemFAddr | ModRM | Src2FS, em_lseg),