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Commit 55f76704 authored by David Edmondson's avatar David Edmondson Committed by Greg Kroah-Hartman
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KVM: x86: clflushopt should be treated as a no-op by emulation 



commit 51b958e5aeb1e18c00332e0b37c5d4e95a3eff84 upstream.

The instruction emulator ignores clflush instructions, yet fails to
support clflushopt. Treat both similarly.

Fixes: 13e457e0 ("KVM: x86: Emulator does not decode clflush well")
Signed-off-by: default avatarDavid Edmondson <david.edmondson@oracle.com>
Message-Id: <20201103120400.240882-1-david.edmondson@oracle.com>
Reviewed-by: default avatarJoao Martins <joao.m.martins@oracle.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent e99d5ec2

arch/x86/kvm/emulate.c

+7 −1
Original line number Diff line number Diff line
@@ -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 = { {