Messages in this thread | | | Date | Wed, 8 Apr 2020 17:09:34 +0900 | From | Masami Hiramatsu <> | Subject | Re: [PATCH 3/4] x86,module: Detect VMX vs SLD conflicts |
| |
On Tue, 07 Apr 2020 13:02:39 +0200 Peter Zijlstra <peterz@infradead.org> wrote:
> +static bool insn_is_vmx(struct insn *insn) > +{ > + u8 modrm = insn->modrm.bytes[0]; > + u8 modrm_mod = X86_MODRM_MOD(modrm); > + u8 modrm_reg = X86_MODRM_REG(modrm); > + > + u8 prefix = insn->prefixes.bytes[0];
This should be the last prefix,
u8 prefix = insn->prefixes.bytes[3];
(The last prefix always copied on the bytes[3])
> + > + if (insn->opcode.bytes[0] != 0x0f) > + return false; > + > + switch (insn->opcode.bytes[1]) { > + case 0x01: > + switch (insn->opcode.bytes[2]) {
Sorry, VMCALL etc. is in Grp7 (0f 01), the 3rd code is embedded in modrm instead of opcode. Thus it should be,
switch (insn->modrm.value) {
> + case 0xc1: /* VMCALL */ > + case 0xc2: /* VMLAUNCH */ > + case 0xc3: /* VMRESUME */ > + case 0xc4: /* VMXOFF */
case 0xd4: /* VMFUNC */
> + return true; > + > + default: > + break; > + } > + break; > + > + case 0x78: /* VMREAD */ > + case 0x79: /* VMWRITE */
return !insn_is_evex(insn);
With EVEX prefix, these becomes vcvt* instructions.
> + case 0xc7: > + /* VMPTRLD, VMPTRST, VMCLEAR, VMXON */ > + if (modrm_mod == 0x03) > + break; > + > + if ((modrm_reg == 6 && (!prefix || prefix == 0x66 || prefix == 0xf3)) || > + (modrm_reg == 7 && (!prefix || prefix == 0xf3))) > + return true; > + > + break; > + > + default: > + break; > + } > + > + return false; > +}
Thank you,
-- Masami Hiramatsu <mhiramat@kernel.org>
| |