Re: [Qemu-devel] [PATCH 3/3] i386/kvm: initialize struct at full before ioctl call

Christian Borntraeger
2019-07-30T17:10:07Z

On 30.07.19 18:46, Peter Maydell wrote:
> On Tue, 30 Jul 2019 at 17:05, Andrey Shinkevich
> <andrey.shinkevich@virtuozzo.com> wrote:
>>
>> Not the whole structure is initialized before passing it to the KVM.
>> Reduce the number of Valgrind reports.
>>
>> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
>
> Does it even make sense to try to valgrind a KVM-enabled run
> of QEMU? As soon as we run the guest it will make modifications
> to memory which Valgrind can't track; and I don't think
> Valgrind supports the KVM_RUN ioctl anyway...

As long as we do not care about the guest memory, it does make sense
and it does find bugs.

See also
https://www.linux-kvm.org/page/KVM_Forum_2014
https://www.linux-kvm.org/images/d/d2/03x07-Valgrind.pdf

Unfortunately I wasnt able to follow up on those.