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Re: [PATCH] x86/S3: put data segment registers into known state upon resume

  • To: Jan Beulich <jbeulich@xxxxxxxx>
  • From: Roger Pau Monné <roger.pau@xxxxxxxxxx>
  • Date: Tue, 21 Jul 2020 13:27:00 +0200
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  • Cc: "xen-devel@xxxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxxx>, "M. Vefa Bicakci" <m.v.b@xxxxxxxxxx>, Wei Liu <wl@xxxxxxx>, Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
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On Mon, Jul 20, 2020 at 05:20:15PM +0200, Jan Beulich wrote:
> wakeup_32 sets %ds and %es to BOOT_DS, while leaving %fs at what
> wakeup_start did set it to, and %gs at whatever BIOS did load into it.
> All of this may end up confusing the first load_segments() to run on
> the BSP after resume, in particular allowing a non-nul selector value
> to be left in %fs.
> Alongside %ss, also put all other data segment registers into the same
> state that the boot and CPU bringup paths put them in.
> Reported-by: M. Vefa Bicakci <m.v.b@xxxxxxxxxx>
> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

Reviewed-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>

I wouldn't mind if the added chunk was placed before loading %ss, so
that the context of what's in %eax would be clearer.




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