Messages in this thread | | | Date | Tue, 17 Nov 2020 15:16:20 +0100 | From | Stefano Garzarella <> | Subject | Re: [PATCH RFC 04/12] vdpa: add vdpa simulator for block device |
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On Tue, Nov 17, 2020 at 11:11:21AM +0000, Stefan Hajnoczi wrote: >On Fri, Nov 13, 2020 at 02:47:04PM +0100, Stefano Garzarella wrote: >> +static void vdpasim_blk_work(struct work_struct *work) >> +{ >> + struct vdpasim *vdpasim = container_of(work, struct vdpasim, work); >> + u8 status = VIRTIO_BLK_S_OK; >> + int i; >> + >> + spin_lock(&vdpasim->lock); >> + >> + if (!(vdpasim->status & VIRTIO_CONFIG_S_DRIVER_OK)) >> + goto out; >> + >> + for (i = 0; i < VDPASIM_BLK_VQ_NUM; i++) { >> + struct vdpasim_virtqueue *vq = &vdpasim->vqs[i]; >> + >> + if (!vq->ready) >> + continue; >> + >> + while (vringh_getdesc_iotlb(&vq->vring, &vq->iov, &vq->iov, >> + &vq->head, GFP_ATOMIC) > 0) { >> + >> + int write; >> + >> + vq->iov.i = vq->iov.used - 1; >> + write = vringh_iov_push_iotlb(&vq->vring, &vq->iov, &status, 1); >> + if (write <= 0) >> + break; > >We're lucky the guest driver doesn't crash after VIRTIO_BLK_T_GET_ID? :)
The crash could happen if the simulator doesn't put the string terminator, but in virtio_blk.c, the serial_show() initialize the buffer putting the string terminator in the VIRTIO_BLK_ID_BYTES element:
buf[VIRTIO_BLK_ID_BYTES] = '\0'; err = virtblk_get_id(disk, buf);
This should prevent the issue, right?
However in the last patch of this series I implemented VIRTIO_BLK_T_GET_ID support :-)
Thanks, Stefano
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