Re: [RFC/RFT PATCH 0/2] x86: sgx_vepc: implement ioctl to EREMOVE all pages

From: Jarkko Sakkinen
Date: Tue Sep 14 2021 - 12:43:09 EST


On Tue, 2021-09-14 at 12:19 +0200, Paolo Bonzini wrote:
> On 14/09/21 09:10, Yang Zhong wrote:
> > On Mon, Sep 13, 2021 at 09:11:51AM -0400, Paolo Bonzini wrote:
> > > Based on discussions from the previous week(end), this series implements
> > > a ioctl that performs EREMOVE on all pages mapped by a /dev/sgx_vepc
> > > file descriptor. Other possibilities, such as closing and reopening
> > > the device, are racy.
> > >
> > > The patches are untested, but I am posting them because they are simple
> > > and so that Yang Zhong can try using them in QEMU.
> > >
> >
> > Paolo, i re-implemented one reset patch in the Qemu side to call this ioctl(),
> > and did some tests on Windows and Linux guest, the Windows/Linux guest reboot
> > work well.
> >
> > So, it is time for me to send this reset patch to Qemu community? or wait for
> > this kernel patchset merged? thanks!
>
> Let's wait for this patch to be accepted first. I'll wait a little more
> for Jarkko and Dave to comment on this, and include your "Tested-by".
>
> I will also add cond_resched() on the final submission.

Why these would be conflicting tasks? I.e. why could not QEMU use
what is available now and move forward using better mechanism, when
they are available?

BTW, I do all my SGX testing ATM in QEMU (for some weeks). IMHO, it's
already "good enough" for many tasks, even if this fallback case is
not perfectly sorted out.

/Jarkko