[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH for-4.7] x86/hvm: Correct emulation of invlpg instruction
On 22/04/16 10:57, Jan Beulich wrote: >>>> On 22.04.16 at 11:48, <Paul.Durrant@xxxxxxxxxx> wrote: >>> From: Jan Beulich [mailto:JBeulich@xxxxxxxx] >>> Sent: 22 April 2016 10:31 >>>>>> On 22.04.16 at 10:59, <andrew.cooper3@xxxxxxxxxx> wrote: >>>> --- a/xen/arch/x86/hvm/emulate.c >>>> +++ b/xen/arch/x86/hvm/emulate.c >>>> @@ -1598,8 +1598,27 @@ static int hvmemul_invlpg( >>>> rc = hvmemul_virtual_to_linear( >>>> seg, offset, 1, &reps, hvm_access_none, hvmemul_ctxt, &addr); >>>> >>>> - if ( rc == X86EMUL_OKAY ) >>>> + switch ( rc ) >>>> + { >>>> + case X86EMUL_OKAY: >>>> hvm_funcs.invlpg_intercept(addr); >>>> + break; >>>> + >>>> + case X86EMUL_EXCEPTION: >>>> + ASSERT(hvmemul_ctxt->trap.vector == TRAP_gp_fault); >>>> + /* >>>> + * `invlpg` and `invlpga` are specified to be NOPs when issued on >>>> a >>>> + * non-canonical address. hvmemul_virtual_to_linear() latches a >>>> #GP >>>> + * which is the useful behaviour for most of its callers. >>> Here and in the description I'd prefer you to not exclusively refer >>> to non-canonical addresses - segment limit violations in 32-bit or >>> compatibility modes are affected as much. >> ...in which case squashing the #GP would be incorrect, right? > No, not according to the SDM. I should check and only squash a #GP(0) #GP(sel) or #SS(sel) should not be squashed. v2 on its way. ~Andrew _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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