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Re: [Xen-devel] [ARM] Bash often segfaults in Dom0 with the latest Xen

On 11 June 2013 04:48, Julien Grall <julien.grall@xxxxxxxxxx> wrote:
> On 06/05/2013 02:38 AM, Christoffer Dall wrote:
>> - All other cache accesses should be coherent across cores and are
>> physically indexed/physically tagged so I don't see how this could be
>> your issue.
> I was looking on KVM code and I noticed that it traps all data cache
> instruction. Is there any reason to trap it?
> I wonder if it could be the issue on Xen because we don't trap cache
> instruction and the manual is not clear on that.
We don't trap all cache maintenance instructions, only those that work
by set/way, since if the vcpu gets migrated in the middle, it will
potentially clean one pcpu partially and another pcpu partially. So we
simply stop everything, clean everything, and carry on. Luckily, this
is not very common with linux guests.

This may be your issue if it really happens...

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