From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Hajnoczi Subject: Re: [PATCH v1] virtio-scsi: get and set the queue limits for sg device Date: Tue, 21 Aug 2012 09:53:59 +0100 Message-ID: References: <1345537609-21676-1-git-send-email-mc@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1345537609-21676-1-git-send-email-mc@linux.vnet.ibm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: Cong Meng Cc: stefanha@linux.vnet.ibm.com, zwanp@cn.ibm.com, linuxram@us.ibm.com, qemu-devel@nongnu.org, linux-kernel@vger.kernel.org, Paolo Bonzini , virtualization@lists.linux-foundation.org List-Id: virtualization@lists.linuxfoundation.org On Tue, Aug 21, 2012 at 9:26 AM, Cong Meng wrote: > Each virtio scsi HBA has global request queue limits. But the passthrough > LUNs (scsi-generic) come from different host HBAs may have different request > queue limits. If the guest sends commands that exceed the host limits, the > commands will be rejected by host HAB. > > This patch addresses this issue by getting the per-LUN queue limits via the the > newly added virtio control request, then setting them properly. > > Signed-off-by: Cong Meng > --- > drivers/scsi/virtio_scsi.c | 113 +++++++++++++++++++++++++++++++++++++------ > include/linux/virtio_scsi.h | 18 +++++++ > 2 files changed, 116 insertions(+), 15 deletions(-) > > diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c > index 173cb39..ec5066f 100644 > --- a/drivers/scsi/virtio_scsi.c > +++ b/drivers/scsi/virtio_scsi.c > @@ -35,12 +35,14 @@ struct virtio_scsi_cmd { > struct virtio_scsi_cmd_req cmd; > struct virtio_scsi_ctrl_tmf_req tmf; > struct virtio_scsi_ctrl_an_req an; > + struct virtio_scsi_ctrl_lq_req lq; > } req; > union { > struct virtio_scsi_cmd_resp cmd; > struct virtio_scsi_ctrl_tmf_resp tmf; > struct virtio_scsi_ctrl_an_resp an; > struct virtio_scsi_event evt; > + struct virtio_scsi_ctrl_lq_resp lq; > } resp; > } ____cacheline_aligned_in_smp; > > @@ -469,6 +471,46 @@ out: > return ret; > } > > +static u32 virtscsi_lun_query(struct scsi_device *sdev, u32 *value, u32 subtype) > +{ > + struct Scsi_Host *shost = sdev->host; > + struct virtio_scsi *vscsi = shost_priv(shost); > + DECLARE_COMPLETION_ONSTACK(comp); > + struct virtio_scsi_cmd *cmd; > + struct virtio_scsi_target_state *tgt = vscsi->tgt[sdev->id]; > + unsigned int ret = VIRTIO_SCSI_S_FAILURE; > + > + cmd = mempool_alloc(virtscsi_cmd_pool, GFP_ATOMIC); > + if (!cmd) > + goto out; > + > + memset(cmd, 0, sizeof(*cmd)); > + cmd->comp = ∁ > + cmd->req.lq = (struct virtio_scsi_ctrl_lq_req){ > + .type = VIRTIO_SCSI_T_LUN_QUERY, > + .subtype = subtype, > + .lun[0] = 1, > + .lun[1] = sdev->id, > + .lun[2] = (sdev->lun >> 8) | 0x40, > + .lun[3] = sdev->lun & 0xff, The LUN addressing code has been duplicated several times now. How about replacing it with something like static void virtio_scsi_set_lun(u8 *lun, struct scsi_device *sdev) { lun[0] = 1; lun[1] = sdev->id; lun[2] = (sdev->lun >> 8) | 0x40; lun[3] = sdev->lun & 0xff; lun[4] = lun[5] = lun[6] = lun[7] = 0; }