Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 15/15] KVM: x86: clflushopt should be treated as a no-op by emulation | Date | Fri, 20 Nov 2020 12:03:13 +0100 |
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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 @@ -3922,6 +3922,12 @@ 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; @@ -4411,7 +4417,7 @@ 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 = { {
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