On 26/06/18 07:36, Jan Beulich wrote:
> Just in case we still don't get CR0.TS handling right, prevent a host
> crash by honoring exception fixups in do_device_not_available(). This
> would in particular cover emulator stubs raising #NM.
>
> Signed-off-by: Jan Beulich <jbeul...@suse.com>
> ---
> v2: Add ASSERT_UNREACHABLE().
>
> --- a/xen/arch/x86/traps.c
> +++ b/xen/arch/x86/traps.c
> @@ -1749,7 +1749,21 @@ void do_device_not_available(struct cpu_
> {
> struct vcpu *curr = current;
>
> - BUG_ON(!guest_mode(regs));
> + if ( !guest_mode(regs) )
> + {
> + unsigned long fixup = search_exception_table(regs);
> +
> + dprintk(XENLOG_ERR, "#NM: %p [%ps] -> %p\n",
gprintk() please. the current vcpu is very likely relevant, and it
would be extremely useful to see this line in release builds where it to
happen.
> + _p(regs->rip), _p(regs->rip), _p(fixup));
> + /*
> + * We mustn't come here, but for release builds have the recovery
"We shouldn't be able to reach here..."
Otherwise, Reviewed-by: Andrew Cooper <andrew.coop...@citrix.com>
> + * logic in place nevertheless.
> + */
> + ASSERT_UNREACHABLE();
> + BUG_ON(!fixup);
> + regs->rip = fixup;
> + return;
> + }
>
> vcpu_restore_fpu_lazy(curr);
>
>
>
>
>
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