Re: [PATCH V2 WIP 0/2] vhost-scsi: new device supporting the tcm_vhost Linux kernel module

Asias He
2013-03-15T00:55:32Z

On Thu, Mar 14, 2013 at 11:46:43AM +0200, Michael S. Tsirkin wrote:
> On Thu, Mar 14, 2013 at 05:25:42PM +0800, Asias He wrote:
> > On Thu, Mar 14, 2013 at 12:25:14PM +0800, Asias He wrote:
> > > On Tue, Mar 12, 2013 at 02:29:40PM +0800, Asias He wrote:
> > > > This is on top of Paolo and Nick's work.
> > > >
> > > > Current status:
> > > > Works now (guest boots fine, no hang any more) with seabios's virtio-scsi disabled.
> > > > Rebased to latest qemu.org/master
> > > > Change details are in commit log.
> > > >
> > > > TODO:
> > > > Make seabios happy.
> > >
> > > Some updates:
> > >
> > > In seabios, src/virtio-scsi.c:virtio_scsi_cmd()
> > >
> > > vring_kick(ioaddr, vq, 1);
> > > /* Wait for reply */
> > > while (!vring_more_used(vq)) ------------>>> we hang here
> > > usleep(5);
> > >
> > > In tcm_vhost:
> > > we got: vhost_get_vq_desc: head: -14, out: 0 in: 81216
> > >
> > > The vring buffer provided by seabios is not correct?
> >
> > More updates:
> >
> > Basically, seabios + tcm_vhost works now, with the attached qemu and
> > seabios patches.
> >
> > We still have one more issue, vhost_verify_ring_mappings fails.
> >
> > I am seeing this without the comment out hack.
> >
> > Unable to map ring buffer for ring 2
> > qemu-system-x86_64: /root/src/qemu/hw/vhost.c:426: vhost_set_memory:
> > Assertion `r >= 0' failed.
> >
>
> Hmm it looks like a bug in cpu_physical_memory_map.
> I think it can make length larger than what was passed in.
> Could you try the following and see what happens?

I got:

Unable to map ring buffer for ring 2 Debug data: 0x7f40d4005000 1000 1404

qemu-system-x86_64: /root/src/qemu/hw/vhost.c:431: vhost_set_memory:
Assertion `r >= 0' failed.

> diff --git a/hw/vhost.c b/hw/vhost.c
> index 37777c2..a30e551 100644
> --- a/hw/vhost.c
> +++ b/hw/vhost.c
> @@ -320,7 +320,9 @@ static int vhost_verify_ring_mappings(struct vhost_dev *dev,
> l = vq->ring_size;
> p = cpu_physical_memory_map(vq->ring_phys, &l, 1);
> if (!p || l != vq->ring_size) {
> - fprintf(stderr, "Unable to map ring buffer for ring %d\n", i);
> + fprintf(stderr, "Unable to map ring buffer for ring %d "
> + "Debug data: %p %llx %llx\n", i, p,
> + (unsigned long long)l, (unsigned long long)vq->ring_size);
> return -ENOMEM;
> }
> if (p != vq->ring) {
>
>
> > > > Paolo Bonzini (2):
> > > > virtio-scsi: create VirtIOSCSICommon
> > > > vhost-scsi: new device supporting the tcm_vhost Linux kernel module
> > > >
> > > > hw/Makefile.objs | 5 +-
> > > > hw/s390x/s390-virtio-bus.c | 35 +++++++
> > > > hw/vhost-scsi.c | 242 +++++++++++++++++++++++++++++++++++++++++++++
> > > > hw/vhost-scsi.h | 64 ++++++++++++
> > > > hw/virtio-pci.c | 59 +++++++++++
> > > > hw/virtio-scsi.c | 199 +++++++++----------------------------
> > > > hw/virtio-scsi.h | 129 ++++++++++++++++++++++++
> > > > include/qemu/osdep.h | 4 +
> > > > 8 files changed, 586 insertions(+), 151 deletions(-)
> > > > create mode 100644 hw/vhost-scsi.c
> > > > create mode 100644 hw/vhost-scsi.h
> > > >
> > > > --
> > > > 1.8.1.4
> > > >
> > >
> > > --
> > > Asias
> >
> > --------------- 8 ---------------> qemu patch:
> > diff --git a/hw/vhost.c b/hw/vhost.c
> > index 4d6aee3..0c52ec4 100644
> > --- a/hw/vhost.c
> > +++ b/hw/vhost.c
> > @@ -421,10 +421,12 @@ static void vhost_set_memory(MemoryListener *listener,
> > return;
> > }
> >
> > +#if 0
> > if (dev->started) {
> > r = vhost_verify_ring_mappings(dev, start_addr, size);
> > assert(r >= 0);
> > }
> > +#endif
> >
> > if (!dev->log_enabled) {
> > r = ioctl(dev->control, VHOST_SET_MEM_TABLE, dev->mem);
> >
> > --------------- 8 ---------------> seabios patch:
> > diff --git a/src/virtio-scsi.c b/src/virtio-scsi.c
> > index 879ddfb..4de1255 100644
> > --- a/src/virtio-scsi.c
> > +++ b/src/virtio-scsi.c
> > @@ -147,6 +147,9 @@ init_virtio_scsi(struct pci_device *pci)
> > goto fail;
> > }
> >
> > + vp_set_status(ioaddr, VIRTIO_CONFIG_S_ACKNOWLEDGE |
> > + VIRTIO_CONFIG_S_DRIVER | VIRTIO_CONFIG_S_DRIVER_OK);
> > +
> > int i, tot;
> > for (tot = 0, i = 0; i < 256; i++)
> > tot += virtio_scsi_scan_target(pci, ioaddr, vq, i);
> > @@ -154,8 +157,6 @@ init_virtio_scsi(struct pci_device *pci)
> > if (!tot)
> > goto fail;
> >
> > - vp_set_status(ioaddr, VIRTIO_CONFIG_S_ACKNOWLEDGE |
> > - VIRTIO_CONFIG_S_DRIVER | VIRTIO_CONFIG_S_DRIVER_OK);
> > return;
> >
> > fail:
> > diff --git a/src/virtio-scsi.h b/src/virtio-scsi.h
> > index bbfbf30..96c3701 100644
> > --- a/src/virtio-scsi.h
> > +++ b/src/virtio-scsi.h
> > @@ -26,7 +26,7 @@ struct virtio_scsi_req_cmd {
> > u8 prio;
> > u8 crn;
> > char cdb[VIRTIO_SCSI_CDB_SIZE];
> > -};
> > +} __attribute__((packed));
> >
> > /* This is the first element of the "in" scatter-gather list. */
> > struct virtio_scsi_resp_cmd {
> > @@ -36,7 +36,7 @@ struct virtio_scsi_resp_cmd {
> > u8 status;
> > u8 response;
> > u8 sense[VIRTIO_SCSI_SENSE_SIZE];
> > -};
> > +} __attribute__((packed));
> >
> > #define VIRTIO_SCSI_S_OK 0
>
> I see, the padding creates the problem?
>
> > --
> > Asias

--
Asias