diff options
| author | Masami Hiramatsu <mhiramat@kernel.org> | 2019-09-06 22:14:10 +0900 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2019-10-17 21:31:57 +0200 |
| commit | 4d65adfcd1196818659d3bd9b42dccab291e1751 (patch) | |
| tree | 5bbd7d53237302e8e65bc7ff9b06320129b2d5f6 /tools/arch/x86/include/asm/emulate_prefix.h | |
| parent | b3dc0695fa40c3b280230fb6fb7fb7a94ce28bf4 (diff) | |
x86: xen: insn: Decode Xen and KVM emulate-prefix signature
Decode Xen and KVM's emulate-prefix signature by x86 insn decoder.
It is called "prefix" but actually not x86 instruction prefix, so
this adds insn.emulate_prefix_size field instead of reusing
insn.prefixes.
If x86 decoder finds a special sequence of instructions of
XEN_EMULATE_PREFIX and 'ud2a; .ascii "kvm"', it just counts the
length, set insn.emulate_prefix_size and fold it with the next
instruction. In other words, the signature and the next instruction
is treated as a single instruction.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: x86@kernel.org
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: xen-devel@lists.xenproject.org
Cc: Randy Dunlap <rdunlap@infradead.org>
Link: https://lkml.kernel.org/r/156777564986.25081.4964537658500952557.stgit@devnote2
Diffstat (limited to 'tools/arch/x86/include/asm/emulate_prefix.h')
| -rw-r--r-- | tools/arch/x86/include/asm/emulate_prefix.h | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/tools/arch/x86/include/asm/emulate_prefix.h b/tools/arch/x86/include/asm/emulate_prefix.h new file mode 100644 index 000000000000..70f5b98a5286 --- /dev/null +++ b/tools/arch/x86/include/asm/emulate_prefix.h @@ -0,0 +1,14 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_X86_EMULATE_PREFIX_H +#define _ASM_X86_EMULATE_PREFIX_H + +/* + * Virt escape sequences to trigger instruction emulation; + * ideally these would decode to 'whole' instruction and not destroy + * the instruction stream; sadly this is not true for the 'kvm' one :/ + */ + +#define __XEN_EMULATE_PREFIX 0x0f,0x0b,0x78,0x65,0x6e /* ud2 ; .ascii "xen" */ +#define __KVM_EMULATE_PREFIX 0x0f,0x0b,0x6b,0x76,0x6d /* ud2 ; .ascii "kvm" */ + +#endif |