Re: [Xen-devel] preparations for 4.9.2 and 4.7.5

[Lars Kurth <lars.kurth@xxxxxxxxxx>]

Alright,
these are now at 
* 
https://xenproject.org/downloads/xen-archives/xen-project-47-series/xen-475.html
* 
https://xenproject.org/downloads/xen-archives/xen-project-49-series/xen-492.html
Blog post and mails will follow shortly (as Jan is OO today)
Regards
Lars

On 04/04/2018, 11:37, "Lars Kurth" <lars.kurth@xxxxxxxxxx> wrote:

    Folks,
    I have not created the webpages for these. The script I am using to 
generate these depends on a script in xsa.git, which fails at the moment due to 
a missing new package dependency that I can't resolve as I don't have root 
access
    Lars 
    
    On 04/04/2018, 10:59, "Julien Grall" <julien.grall@xxxxxxx> wrote:
    
        Hi Stefano,
        
        On 04/04/18 00:55, Stefano Stabellini wrote:
        > On Tue, 3 Apr 2018, Julien Grall wrote:
        >> Hi,
        >>
        >> On 16/03/18 17:15, Julien Grall wrote:
        >>>
        >>>
        >>> On 16/03/2018 16:56, Julien Grall wrote:
        >>>> 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.
        >>>
        >>> To be clear, for Xen 4.10 it is just a matter of dropping the 3 
patches I
        >>> suggested. There are actually no clash with the current code.
        >>
        >> Gentle ping. Is there anything blocking to get those patches in Xen 
4.10?
        > 
        > Done! Thanks for the ping!
        
        It looks like the commit 6b270fae7ad462687550a875f714bff18d764416 
        "xen/arm: Relax ARM_SMCCC_ARCH_WORKAROUND_1 discovery" is missing in 
Xen 
        4.10.
        
        Cheers,
        
        -- 
        Julien Grall
        
    
    

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