Re: [PATCH 02/16] x86/entry/32: Enter the kernel via trampoline stack

[Joerg Roedel]

Hi Boris,

thanks for testing this :)

On Tue, Jan 16, 2018 at 09:47:06PM -0500, Boris Ostrovsky wrote:
> On 01/16/2018 11:36 AM, Joerg Roedel wrote:
> >+.macro SWITCH_TO_KERNEL_STACK nr_regs=0 check_user=0
> 
> 
> This (and next patch's SWITCH_TO_ENTRY_STACK) need X86_FEATURE_PTI check.
> 
> With those macros fixed I was able to boot 32-bit Xen PV guest.

Hmm, on bare metal the stack switch happens regardless of the
X86_FEATURE_PTI feature being set, because we always program tss.sp0
with the systenter stack. How is the kernel entry stack setup on xen-pv?
I think something is missing there instead.

Regards,

	Joerg