[PATCH] KVM: x86: emulate reserved nops from 0f/18 to 0f/1f

Paolo Bonzini
2020-05-15T16:19:25Z

Instructions starting with 0f18 up to 0f1f are reserved nops, except those
that were assigned to MPX. These include the endbr markers used by CET.
List them correctly in the opcode table.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/kvm/emulate.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index de5476f8683e..d0e2825ae617 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -4800,8 +4800,12 @@ static const struct opcode twobyte_table[256] = {
GP(ModRM | DstReg | SrcMem | Mov | Sse, &pfx_0f_10_0f_11),
GP(ModRM | DstMem | SrcReg | Mov | Sse, &pfx_0f_10_0f_11),
N, N, N, N, N, N,
- D(ImplicitOps | ModRM | SrcMem | NoAccess),
- N, N, N, N, N, N, D(ImplicitOps | ModRM | SrcMem | NoAccess),
+ D(ImplicitOps | ModRM | SrcMem | NoAccess), /* 4 * prefetch + 4 * reserved NOP */
+ D(ImplicitOps | ModRM | SrcMem | NoAccess), N, N,
+ D(ImplicitOps | ModRM | SrcMem | NoAccess), /* 8 * reserved NOP */
+ D(ImplicitOps | ModRM | SrcMem | NoAccess), /* 8 * reserved NOP */
+ D(ImplicitOps | ModRM | SrcMem | NoAccess), /* 8 * reserved NOP */
+ D(ImplicitOps | ModRM | SrcMem | NoAccess), /* NOP + 7 * reserved NOP */
/* 0x20 - 0x2F */
DIP(ModRM | DstMem | Priv | Op3264 | NoMod, cr_read, check_cr_read),
DIP(ModRM | DstMem | Priv | Op3264 | NoMod, dr_read, check_dr_read),
--
2.18.2