[lkml]   [2018]   [Jan]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH 02/16] x86/entry/32: Enter the kernel via trampoline stack
On 17/01/18 09:02, Joerg Roedel wrote:
> 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.

There is one single stack registered with Xen, on which you get a normal
exception frame in all cases, even via the registered (virtual)
syscall/sysenter/failsafe handlers.


 \ /
  Last update: 2018-01-18 00:20    [W:0.104 / U:0.172 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site