Re: Setting constant-time mode CPU flag

2022-09-14 Thread Demi Marie Obenour
On Wed, Sep 14, 2022 at 09:32:20AM +0200, Jan Beulich wrote: > On 14.09.2022 09:11, Demi Marie Obenour wrote: > > On Wed, Sep 14, 2022 at 08:44:25AM +0200, Jan Beulich wrote: > >> On 14.09.2022 08:40, Demi Marie Obenour wrote: > >>> On Wed, Sep 14, 2022 at 08:36:02AM +0200, Jan Beulich wrote: > >>>

Re: Setting constant-time mode CPU flag

2022-09-14 Thread Jan Beulich
On 14.09.2022 09:11, Demi Marie Obenour wrote: > On Wed, Sep 14, 2022 at 08:44:25AM +0200, Jan Beulich wrote: >> On 14.09.2022 08:40, Demi Marie Obenour wrote: >>> On Wed, Sep 14, 2022 at 08:36:02AM +0200, Jan Beulich wrote: On 13.09.2022 19:22, Demi Marie Obenour wrote: > On Tue, Sep 13,

Re: Setting constant-time mode CPU flag

2022-09-14 Thread Demi Marie Obenour
On Wed, Sep 14, 2022 at 08:44:25AM +0200, Jan Beulich wrote: > On 14.09.2022 08:40, Demi Marie Obenour wrote: > > On Wed, Sep 14, 2022 at 08:36:02AM +0200, Jan Beulich wrote: > >> On 13.09.2022 19:22, Demi Marie Obenour wrote: > >>> On Tue, Sep 13, 2022 at 04:47:24PM +0200, Jan Beulich wrote: > >>>

Re: Setting constant-time mode CPU flag

2022-09-13 Thread Jan Beulich
On 14.09.2022 08:40, Demi Marie Obenour wrote: > On Wed, Sep 14, 2022 at 08:36:02AM +0200, Jan Beulich wrote: >> On 13.09.2022 19:22, Demi Marie Obenour wrote: >>> On Tue, Sep 13, 2022 at 04:47:24PM +0200, Jan Beulich wrote: On 13.09.2022 16:22, Demi Marie Obenour wrote: > On Tue, Sep 06,

Re: Setting constant-time mode CPU flag

2022-09-13 Thread Demi Marie Obenour
On Wed, Sep 14, 2022 at 08:36:02AM +0200, Jan Beulich wrote: > On 13.09.2022 19:22, Demi Marie Obenour wrote: > > On Tue, Sep 13, 2022 at 04:47:24PM +0200, Jan Beulich wrote: > >> On 13.09.2022 16:22, Demi Marie Obenour wrote: > >>> On Tue, Sep 06, 2022 at 10:01:00AM +, Andrew Cooper wrote: > >

Re: Setting constant-time mode CPU flag

2022-09-13 Thread Jan Beulich
On 13.09.2022 19:22, Demi Marie Obenour wrote: > On Tue, Sep 13, 2022 at 04:47:24PM +0200, Jan Beulich wrote: >> On 13.09.2022 16:22, Demi Marie Obenour wrote: >>> On Tue, Sep 06, 2022 at 10:01:00AM +, Andrew Cooper wrote: On 06/09/2022 10:52, Jan Beulich wrote: > On 02.09.2022 04:05,

Re: Setting constant-time mode CPU flag

2022-09-13 Thread Demi Marie Obenour
On Tue, Sep 13, 2022 at 04:47:24PM +0200, Jan Beulich wrote: > On 13.09.2022 16:22, Demi Marie Obenour wrote: > > On Tue, Sep 06, 2022 at 10:01:00AM +, Andrew Cooper wrote: > >> On 06/09/2022 10:52, Jan Beulich wrote: > >>> On 02.09.2022 04:05, Demi Marie Obenour wrote: > On Intel chips (I

Re: Setting constant-time mode CPU flag

2022-09-13 Thread Jan Beulich
On 13.09.2022 16:22, Demi Marie Obenour wrote: > On Tue, Sep 06, 2022 at 10:01:00AM +, Andrew Cooper wrote: >> On 06/09/2022 10:52, Jan Beulich wrote: >>> On 02.09.2022 04:05, Demi Marie Obenour wrote: On Intel chips (Ice Lake and later) and ARM64, a bit needs to be set in a CPU regis

Re: Setting constant-time mode CPU flag

2022-09-13 Thread Demi Marie Obenour
On Tue, Sep 06, 2022 at 10:01:00AM +, Andrew Cooper wrote: > On 06/09/2022 10:52, Jan Beulich wrote: > > On 02.09.2022 04:05, Demi Marie Obenour wrote: > >> On Intel chips (Ice Lake and later) and ARM64, a bit needs to be set in > >> a CPU register to enforce constant-time execution. Linux pla

Re: Setting constant-time mode CPU flag

2022-09-07 Thread Bertrand Marquis
Hi Demi, > On 2 Sep 2022, at 03:05, Demi Marie Obenour > wrote: > > On Intel chips (Ice Lake and later) and ARM64, a bit needs to be set in This bit would not change anything on Arm currently so nothing is required for now (and nothing has been done in Linux for ARM64). Thanks a lot for noti

Re: Setting constant-time mode CPU flag

2022-09-06 Thread Andrew Cooper
On 06/09/2022 10:52, Jan Beulich wrote: > On 02.09.2022 04:05, Demi Marie Obenour wrote: >> On Intel chips (Ice Lake and later) and ARM64, a bit needs to be set in >> a CPU register to enforce constant-time execution. Linux plans to set >> this bit by default; Xen should do the same. See >> https

Re: Setting constant-time mode CPU flag

2022-09-06 Thread Jan Beulich
On 02.09.2022 04:05, Demi Marie Obenour wrote: > On Intel chips (Ice Lake and later) and ARM64, a bit needs to be set in > a CPU register to enforce constant-time execution. Linux plans to set > this bit by default; Xen should do the same. See > https://lore.kernel.org/lkml/ywgcrqutxmx0w...@gmail