From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:52119) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T3Nuh-0006fC-J0 for qemu-devel@nongnu.org; Mon, 20 Aug 2012 05:04:51 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1T3Nud-0007nF-63 for qemu-devel@nongnu.org; Mon, 20 Aug 2012 05:04:47 -0400 Received: from mx1.redhat.com ([209.132.183.28]:49930) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T3Nuc-0007n1-Ti for qemu-devel@nongnu.org; Mon, 20 Aug 2012 05:04:43 -0400 Message-ID: <5031FD9E.9080204@redhat.com> Date: Mon, 20 Aug 2012 11:04:30 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <1344846917-7411-1-git-send-email-nab@linux-iscsi.org> <1344846917-7411-5-git-send-email-nab@linux-iscsi.org> In-Reply-To: <1344846917-7411-5-git-send-email-nab@linux-iscsi.org> Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC-v2 4/6] virtio-scsi: Add start/stop functionality for vhost-scsi List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Nicholas A. Bellinger" Cc: Stefan Hajnoczi , kvm-devel , "Michael S. Tsirkin" , Jan Kiszka , Zhi Yong Wu , qemu-devel , Zhi Yong Wu , Anthony Liguori , target-devel , Hannes Reinecke , lf-virt , Christoph Hellwig Il 13/08/2012 10:35, Nicholas A. Bellinger ha scritto: > From: Stefan Hajnoczi > > This patch starts and stops vhost as the virtio device transitions > through its status phases. Vhost can only be started once the guest > reports its driver has successfully initialized, which means the > virtqueues have been set up by the guest. > > v2: - Squash virtio-scsi: use the vhost-scsi host device from stefan (nab) > - Fix up virtio_scsi_properties[] conflict w/ upstream qemu (nab) > - Drop usage of to_virtio_scsi() in virtio_scsi_set_status() > (reported by paolo) > - Use modern VirtIOSCSIConf define in virtio-scsi.h (reported by paolo) > - Use s->conf->vhost_scsi instead of proxyconf->vhost_scsi in > virtio_scsi_init() (reported by paolo) > - Only register QEMU SCSI bus is vhost-scsi is not active (reported > by paolo) How much of the functionality of virtio-scsi.[ch] is still in use at this point? Would it make more sense to use a separate vhost-scsi-pci device instead? Especially since advertising VIRTIO_SCSI_F_HOTPLUG and VIRTIO_SCSI_F_CHANGE is probably wrong for vhost-scsi... Paolo > Cc: Stefan Hajnoczi > Cc: Zhi Yong Wu > Cc: Michael S. Tsirkin > Cc: Paolo Bonzini > Signed-off-by: Nicholas Bellinger > --- > hw/virtio-pci.c | 1 + > hw/virtio-scsi.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ > hw/virtio-scsi.h | 1 + > 3 files changed, 50 insertions(+), 0 deletions(-) > > diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c > index 125eded..b29fc3b 100644 > --- a/hw/virtio-pci.c > +++ b/hw/virtio-pci.c > @@ -1036,6 +1036,7 @@ static void virtio_scsi_exit_pci(PCIDevice *pci_dev) > } > > static Property virtio_scsi_properties[] = { > + DEFINE_PROP_VHOST_SCSI("vhost-scsi", VirtIOPCIProxy, scsi.vhost_scsi), > DEFINE_PROP_BIT("ioeventfd", VirtIOPCIProxy, flags, VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT, true), > DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors, DEV_NVECTORS_UNSPECIFIED), > DEFINE_VIRTIO_SCSI_PROPERTIES(VirtIOPCIProxy, host_features, scsi), > diff --git a/hw/virtio-scsi.c b/hw/virtio-scsi.c > index 5f737ac..8130956 100644 > --- a/hw/virtio-scsi.c > +++ b/hw/virtio-scsi.c > @@ -13,9 +13,13 @@ > * > */ > > +#include "qemu-common.h" > +#include "qemu-error.h" > +#include "vhost-scsi.h" > #include "virtio-scsi.h" > #include > #include > +#include "vhost.h" > > #define VIRTIO_SCSI_VQ_SIZE 128 > #define VIRTIO_SCSI_CDB_SIZE 32 > @@ -147,6 +151,9 @@ typedef struct { > VirtQueue *ctrl_vq; > VirtQueue *event_vq; > VirtQueue *cmd_vqs[0]; > + > + bool vhost_started; > + VHostSCSI *vhost_scsi; > } VirtIOSCSI; > > typedef struct VirtIOSCSIReq { > @@ -699,6 +706,38 @@ static struct SCSIBusInfo virtio_scsi_scsi_info = { > .load_request = virtio_scsi_load_request, > }; > > +static bool virtio_scsi_started(VirtIOSCSI *s, uint8_t val) > +{ > + return (val & VIRTIO_CONFIG_S_DRIVER_OK) && s->vdev.vm_running; > +} > + > +static void virtio_scsi_set_status(VirtIODevice *vdev, uint8_t val) > +{ > + VirtIOSCSI *s = (VirtIOSCSI *)vdev; > + bool start = virtio_scsi_started(s, val); > + > + if (s->vhost_started == start) { > + return; > + } > + > + if (start) { > + int ret; > + > + ret = vhost_scsi_start(s->vhost_scsi, vdev); > + if (ret < 0) { > + error_report("virtio-scsi: unable to start vhost: %s\n", > + strerror(-ret)); > + > + /* There is no userspace virtio-scsi fallback so exit */ > + exit(1); > + } > + } else { > + vhost_scsi_stop(s->vhost_scsi, vdev); > + } > + > + s->vhost_started = start; > +} > + > VirtIODevice *virtio_scsi_init(DeviceState *dev, VirtIOSCSIConf *proxyconf) > { > VirtIOSCSI *s; > @@ -712,12 +751,17 @@ VirtIODevice *virtio_scsi_init(DeviceState *dev, VirtIOSCSIConf *proxyconf) > > s->qdev = dev; > s->conf = proxyconf; > + s->vhost_started = false; > + s->vhost_scsi = s->conf->vhost_scsi; > > /* TODO set up vdev function pointers */ > s->vdev.get_config = virtio_scsi_get_config; > s->vdev.set_config = virtio_scsi_set_config; > s->vdev.get_features = virtio_scsi_get_features; > s->vdev.reset = virtio_scsi_reset; > + if (s->vhost_scsi) { > + s->vdev.set_status = virtio_scsi_set_status; > + } > > s->ctrl_vq = virtio_add_queue(&s->vdev, VIRTIO_SCSI_VQ_SIZE, > virtio_scsi_handle_ctrl); > @@ -743,5 +787,9 @@ void virtio_scsi_exit(VirtIODevice *vdev) > { > VirtIOSCSI *s = (VirtIOSCSI *)vdev; > unregister_savevm(s->qdev, "virtio-scsi", s); > + > + /* This will stop vhost backend if appropriate. */ > + virtio_scsi_set_status(vdev, 0); > + > virtio_cleanup(vdev); > } > diff --git a/hw/virtio-scsi.h b/hw/virtio-scsi.h > index 4bc889d..74e9422 100644 > --- a/hw/virtio-scsi.h > +++ b/hw/virtio-scsi.h > @@ -22,6 +22,7 @@ > #define VIRTIO_ID_SCSI 8 > > struct VirtIOSCSIConf { > + VHostSCSI *vhost_scsi; > uint32_t num_queues; > uint32_t max_sectors; > uint32_t cmd_per_lun; >