On 12.02.20 17:34, Eugenio Pérez wrote: > On Tue, 2020-02-11 at 14:13 +0100, Christian Borntraeger wrote: >> >> On 11.02.20 14:04, Eugenio Pérez wrote: >>> On Mon, 2020-02-10 at 12:01 +0100, Christian Borntraeger wrote: >>>> On 10.02.20 10:47, Eugenio Perez Martin wrote: >>>>> 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? >> >> I still get >> [ 43.665145] Guest moved used index from 0 to 289 >> after some reboots. >> >> >>> Thanks! >>> >>> From 71d0f9108a18aa894cc0c0c1c7efbad39f465a27 Mon Sep 17 00:00:00 2001 >>> From: =?UTF-8?q?Eugenio=20P=C3=A9rez?= < >>> eperezma@xxxxxxxxxx> >>> 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. >>> >>> 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; >>> > > Sorry, still not able to reproduce the issue. > > Could we try to disable all the vhost features? > > Thanks! > > diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h > index 661088ae6dc7..08f6d2ccb697 100644 > --- a/drivers/vhost/vhost.h > +++ b/drivers/vhost/vhost.h > @@ -250,11 +250,11 @@ int vhost_init_device_iotlb(struct vhost_dev *d, bool enabled); > } while (0) > > enum { > - VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) | > - (1ULL << VIRTIO_RING_F_INDIRECT_DESC) | > - (1ULL << VIRTIO_RING_F_EVENT_IDX) | > - (1ULL << VHOST_F_LOG_ALL) | > - (1ULL << VIRTIO_F_ANY_LAYOUT) | > + VHOST_FEATURES = /* (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) | */ > + /* (1ULL << VIRTIO_RING_F_INDIRECT_DESC) | */ > + /* (1ULL << VIRTIO_RING_F_EVENT_IDX) | */ > + /* (1ULL << VHOST_F_LOG_ALL) | */ > + /* (1ULL << VIRTIO_F_ANY_LAYOUT) | */ > (1ULL << VIRTIO_F_VERSION_1) > }; > I still get guest crashes with this on top of eccb852f1fe6. (The patch did not apply, I had to manually comment out these things)