KVM: Clean up unloved invlpg emulation
invlpg shouldn't fetch the "src" address, since it may not be valid,
however SVM's "solution" which neuters emulation of all group 7
instruction is horrible and breaks kvm-lite. The simplest fix is to
put a special check in for invlpg.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/drivers/kvm/x86_emulate.c b/drivers/kvm/x86_emulate.c
index 7439b34..342594d7 100644
--- a/drivers/kvm/x86_emulate.c
+++ b/drivers/kvm/x86_emulate.c
@@ -213,19 +213,6 @@
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
-/*
- * Tell the emulator that of the Group 7 instructions (sgdt, lidt, etc.) we
- * are interested only in invlpg and not in any of the rest.
- *
- * invlpg is a special instruction in that the data it references may not
- * be mapped.
- */
-void kvm_emulator_want_group7_invlpg(void)
-{
- twobyte_table[1] &= ~SrcMem;
-}
-EXPORT_SYMBOL_GPL(kvm_emulator_want_group7_invlpg);
-
/* Type, address-of, and value of an instruction's operand. */
struct operand {
enum { OP_REG, OP_MEM, OP_IMM } type;
@@ -791,6 +778,9 @@
goto srcmem_common;
case SrcMem:
src.bytes = (d & ByteOp) ? 1 : op_bytes;
+ /* Don't fetch the address for invlpg: it could be unmapped. */
+ if (twobyte && b == 0x01 && modrm_reg == 7)
+ break;
srcmem_common:
src.type = OP_MEM;
src.ptr = (unsigned long *)cr2;