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KVM: x86: clflushopt should be treated as a no-op by emulation

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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>
This commit is contained in:
David Edmondson 2020-11-03 12:04:00 +00:00 committed by Greg Kroah-Hartman
parent e99d5ec22e
commit 55f76704ec
1 changed files with 7 additions and 1 deletions
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8
arch/x86/kvm/emulate.c
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@ -3934,6 +3934,12 @@ static int em_clflush(struct x86_emulate_ctxt *ctxt)
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;
@ -4423,7 +4429,7 @@ 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 = { {