Re: vhost changes (batched) in linux-next after 12/13 trigger random crashes in KVM guests after reboot
From: "Michael S. Tsirkin" <mst@redhat.com>
Date: 2020-02-11 13:58:24
Also in:
kvm, linux-next, lkml
Possibly related (same subject, not in this thread)
- 2020-02-10 · Re: vhost changes (batched) in linux-next after 12/13 trigger random crashes in KVM guests after reboot · Christian Borntraeger <hidden>
- 2020-02-07 · Re: vhost changes (batched) in linux-next after 12/13 trigger random crashes in KVM guests after reboot · "Michael S. Tsirkin" <mst@redhat.com>
- 2020-02-07 · Re: vhost changes (batched) in linux-next after 12/13 trigger random crashes in KVM guests after reboot · Cornelia Huck <cohuck@redhat.com>
- 2020-02-07 · Re: vhost changes (batched) in linux-next after 12/13 trigger random crashes in KVM guests after reboot · Christian Borntraeger <hidden>
- 2020-02-07 · Re: vhost changes (batched) in linux-next after 12/13 trigger random crashes in KVM guests after reboot · "Michael S. Tsirkin" <mst@redhat.com>
On Tue, Feb 11, 2020 at 02:04:54PM +0100, Eugenio Pérez wrote:
On Mon, 2020-02-10 at 12:01 +0100, Christian Borntraeger wrote:quoted
On 10.02.20 10:47, Eugenio Perez Martin wrote:quoted
Hi Christian. I'm not able to reproduce the failure with eccb852f1fe6bede630e2e4f1a121a81e34354ab commit. Could you add more data? Your configuration (libvirt or qemu line), and host's dmesg output if any? Thanks!If it was not obvious, this is on s390x, a big endian system.Hi Christian. Thank you very much for your fast responses. Could you try this patch on top of eccb852f1fe6bede630e2e4f1a121a81e34354ab? Thanks!quoted
From 71d0f9108a18aa894cc0c0c1c7efbad39f465a27 Mon Sep 17 00:00:00 2001From: =?UTF-8?q?Eugenio=20P=C3=A9rez?= < eperezma@redhat.com> Date: Tue, 11 Feb 2020 13:19:10 +0100 Subject: [PATCH] vhost: fix return value of vhost_get_vq_desc Before of the batch change, it was the chain's head. Need to keep that way or we will not be able to free a chain of descriptors.
I think it's cleaner to have all descriptors in the chain have the same id.
quoted hunk ↗ jump to hunk
Fixes: eccb852f1fe6 ("vhost: batching fetches") --- drivers/vhost/vhost.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index b5a51b1f2e79..fc422c3e5c08 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c@@ -2409,12 +2409,11 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq, *out_num += ret; } - ret = desc->id; - if (!(desc->flags & VRING_DESC_F_NEXT)) break; } + ret = vq->descs[vq->first_desc].id; vq->first_desc = i + 1; return ret;-- 2.18.1