lkml.org 
[lkml]   [2019]   [Jul]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH V3] KVM: arm64: Implement vq_present() as a macro
On Wed, Jul 03, 2019 at 12:04:11PM +0000, Zhang, Lei wrote:
> Hi guys,
>
> I can't start up KVM guest os with SVE feature with your patch.
> The error message is
> qemu-system-aarch64: kvm_init_vcpu failed: Invalid argument.
>
> My test enviroment.
> kernel linux-5.2-rc6
> qemu [Qemu-devel] [PATCH v2 00/14] target/arm/kvm: enable SVE in guests https://lists.gnu.org/archive/html/qemu-devel/2019-06/msg04945.html
> KVM start up option
> -machine virt,gic-version=host,accel=kvm \
> -cpu host \
> -machine type=virt \
> -nographic \
> -smp 16 \ -m 4096 \
> -drive if=none,file=/root/image.qcow2,id=hd0,format=qcow2 \
> -device virtio-blk-device,drive=hd0 \
> -netdev user,id=mynet0,restrict=off,hostfwd=tcp::38001-:22 \
> -device virtio-net-device,netdev=mynet0 \
> -bios /root/QEMU_EFI.fd
>
> sve_vq_available function's return value' type is bool.
> But vq_present is macro, so the value is not only TRUE, FALSE but also some numbers.
> So It failed at
> if (vq_present(vqs, vq) != sve_vq_available(vq)).
> I think it is nessary to make vq_present macro's value only TRUE and FALSE.
>
> arch/arm64/kvm/guest.c
> static int set_sve_vls(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
> for (vq = SVE_VQ_MIN; vq <= max_vq; ++vq)
> if (vq_present(vqs, vq) != sve_vq_available(vq)) // It failed at here.
> return -EINVAL;
>
> My patch as follows.
> I have started up KVM guest os successfully with SVE feature with this patch.
>
> Could you review and merge my patch?

[...]

Thanks for reporting this! It looks like we didn't realise we dropped
the implicit cast to bool when the result was returned from the original
version of vq_present().

Your fix looks sensible to me.

For the future, see Documentation/process/submitting-patches.rst for
guidance on how to prepare a patch for submission.

However, due to the fact that we're already at -rc7 I've written a
commit message for the patch and reposted [1]. Since the fix is yours,
I'll keep your authorship and S-o-B.

Please retest when you can (though the diff should be the same).

Note, your mail seems to be corrupted, but since the diff is a one-line
fix, I'm pretty confident I decoded it correctly. If anything looks
wrong, please let me know.

[...]

Cheers
---Dave


[1] [PATCH] KVM: arm64/sve: Fix vq_present() macro to yield a bool
http://lists.infradead.org/pipermail/linux-arm-kernel/2019-July/664745.html

\
 
 \ /
  Last update: 2019-07-03 19:47    [W:0.044 / U:4.848 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site