| From 51b958e5aeb1e18c00332e0b37c5d4e95a3eff84 Mon Sep 17 00:00:00 2001 |
| From: David Edmondson <david.edmondson@oracle.com> |
| Date: Tue, 3 Nov 2020 12:04:00 +0000 |
| Subject: KVM: x86: clflushopt should be treated as a no-op by emulation |
| |
| From: David Edmondson <david.edmondson@oracle.com> |
| |
| commit 51b958e5aeb1e18c00332e0b37c5d4e95a3eff84 upstream. |
| |
| The instruction emulator ignores clflush instructions, yet fails to |
| support clflushopt. Treat both similarly. |
| |
| Fixes: 13e457e0eebf ("KVM: x86: Emulator does not decode clflush well") |
| Signed-off-by: David Edmondson <david.edmondson@oracle.com> |
| Message-Id: <20201103120400.240882-1-david.edmondson@oracle.com> |
| Reviewed-by: Joao Martins <joao.m.martins@oracle.com> |
| Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| arch/x86/kvm/emulate.c | 8 +++++++- |
| 1 file changed, 7 insertions(+), 1 deletion(-) |
| |
| --- a/arch/x86/kvm/emulate.c |
| +++ b/arch/x86/kvm/emulate.c |
| @@ -4032,6 +4032,12 @@ static int em_clflush(struct x86_emulate |
| return X86EMUL_CONTINUE; |
| } |
| |
| +static int em_clflushopt(struct x86_emulate_ctxt *ctxt) |
| +{ |
| + /* emulating clflushopt regardless of cpuid */ |
| + return X86EMUL_CONTINUE; |
| +} |
| + |
| static int em_movsxd(struct x86_emulate_ctxt *ctxt) |
| { |
| ctxt->dst.val = (s32) ctxt->src.val; |
| @@ -4571,7 +4577,7 @@ static const struct opcode group11[] = { |
| }; |
| |
| static const struct gprefix pfx_0f_ae_7 = { |
| - I(SrcMem | ByteOp, em_clflush), N, N, N, |
| + I(SrcMem | ByteOp, em_clflush), I(SrcMem | ByteOp, em_clflushopt), N, N, |
| }; |
| |
| static const struct group_dual group15 = { { |
