From: Mihai Donțu <mdontu@xxxxxxxxxxxxxxx>
This adds support for all encoding variants of lfence (0x0f 0xae 0xe[8-f]).
I did not use rmb() in case it will be made to use a different instruction
on future architectures.
Signed-off-by: Mihai Donțu <mdontu@xxxxxxxxxxxxxxx>
Signed-off-by: Adalbert Lazăr <alazar@xxxxxxxxxxxxxxx>
---
arch/x86/kvm/emulate.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index a2e5e63bd94a..287d3751675d 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -4168,6 +4168,12 @@ static int em_fxrstor(struct x86_emulate_ctxt *ctxt)
return rc;
}
+static int em_lfence(struct x86_emulate_ctxt *ctxt)
+{
+ asm volatile ("lfence" ::: "memory");
+ return X86EMUL_CONTINUE;
+}
+
static bool valid_cr(int nr)
{
switch (nr) {
@@ -4554,7 +4560,7 @@ static const struct group_dual group15 = { {
I(ModRM | Aligned16, em_fxrstor),
N, N, N, N, N, GP(0, &pfx_0f_ae_7),
}, {
- N, N, N, N, N, N, N, N,
+ N, N, N, N, N, I(ModRM | Sse, em_lfence), N, N,
} };
static const struct gprefix pfx_0f_6f_0f_7f = {
