Hi Stefano,
On 16/03/2018 16:33, Stefano Stabellini wrote:
On Fri, 16 Mar 2018, Julien Grall wrote:
Hi Stefano,
On 15/03/18 23:52, Stefano Stabellini wrote:
On Wed, 14 Mar 2018, Stefano Stabellini wrote:
After looking at the test results, which are good for arm, and
considering that master hasn't passed yet after 2 more days, I agree
with Julien: I think we should not release 4.9.2 and 4.7.5 without the
arm64 spectre patches. At this point, I'll proceed to backport the
patches now.
Julien, Andre,
Please give a look at the following branches:
git://xenbits.xen.org/people/sstabellini/xen-unstable.git
staging-4.7-spectre
git://xenbits.xen.org/people/sstabellini/xen-unstable.git
staging-4.8-spectre
git://xenbits.xen.org/people/sstabellini/xen-unstable.git
staging-4.9-spectre
For all of the tree above, as I said yesterday, I clearly don't want to see
the smccc framework backport for Xen 4.9 and older. This is a massive changes
of the interface that is not necessary for spectre. My main concern is making
SMC instruction available to the guest.
It would be just sufficient to emulate the few SMCCC function ID we care in
do_trap_psci (function can be renamed).
This is also clearly wrong to backport coding style or code non-justified code
movement (sysreg) just to please the cherry-pick.
I am also worry to bump the version of the emulated PSCI (0.2 -> 1.0) for
those releases. Some guests may rely on a specific version and may now
crashes.
Overall, the right way to support spectre in earlier releases is custom patch
and only do minimal modification.
git://xenbits.xen.org/people/sstabellini/xen-unstable.git
staging-4.10-spectre
The patches below should not be part of spectre nor backport to 4.10:
- 82e29c87dc7f4f2a7e2f111c3646479da21a910a "ARM: remove unneeded gic.h
inclusions"
- 79563717c9dd5383abcf0ba94d813de9b42e3793 "xen/arm: psci: Prefix with
static any functions not exported"
- 6d0e9b21b1f7213c1994cc2d636448ee2d5372c2 "xen/arm: vpsci: Update the
return type for MIGRATE_INFO_TYPE"
The patches below should not be part of spectre but candidate to 4.10:
- c2d70f77cc7987be164cd87b76459782497fc540 "xen/arm: vpsci: Rework the logic
to start AArch32 vCPU in Thumb mode"
You will also want to backport [1] which address a relaxation of the
ARM_SMCCC_ARCH_WORKAROUND_1.
I understand your concerns, in that case could you please provide the
git branches?
That will have to wait when I have spare cycle. Most likely somewhere in
April when I am done from the Xen 4.11 patches and back from holidays.
So It is probably the right time to put into contribution stakeholders
who are using those Xen 4.* stable releases.
Cheers,
[1] https://developer.arm.com/support/security-update/downloads
--
Julien Grall
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