>>> On 30.11.16 at 14:50, <andrew.coop...@citrix.com> wrote:
> --- a/xen/arch/x86/mm/shadow/multi.c
> +++ b/xen/arch/x86/mm/shadow/multi.c
> @@ -3373,18 +3373,35 @@ static int sh_page_fault(struct vcpu *v,
>
> r = x86_emulate(&emul_ctxt.ctxt, emul_ops);
>
> - /*
> - * The previous lack of inject_{sw,hw}*() hooks caused exceptions raised
> - * by the emulator itself to become X86EMUL_UNHANDLEABLE. Such
> exceptions
> - * now set event_pending instead. Exceptions raised behind the back of
> - * the emulator don't yet set event_pending.
> - *
> - * For now, cause such cases to return to the X86EMUL_UNHANDLEABLE path,
> - * for no functional change from before. Future patches will fix this
> - * properly.
> - */
> if ( r == X86EMUL_EXCEPTION && emul_ctxt.ctxt.event_pending )
> - r = X86EMUL_UNHANDLEABLE;
> + {
> + /*
> + * This emulation covers writes to shadow pagetables. We tolerate
> #PF
> + * (from hitting adjacent pages) and #GP/#SS (from segmentation
> + * errors). Anything else is an emulation bug, or a guest playing
> + * with the instruction stream under Xen's feet.
> + */
Same comment here regarding "adjacent".
> + if ( emul_ctxt.ctxt.event.type == X86_EVENTTYPE_HW_EXCEPTION &&
> + (emul_ctxt.ctxt.event.vector < 32) &&
> + ((1u << emul_ctxt.ctxt.event.vector) &
> + ((1u << TRAP_stack_error) | (1u << TRAP_gp_fault) |
> + (1u << TRAP_page_fault))) )
May I suggest to also demand an error code of zero for #GP/#SS?
> + {
> + if ( is_hvm_vcpu(v) )
has_hvm_container_domain()?
Jan
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