2023-11-15 15:05:01

by John Garry

[permalink] [raw]
Subject: Re: [PATCH v3 10/13] scsi: fnic: Add support for multiqueue (MQ) in fnic_main.c

On 14/11/2023 22:38, Karan Tilak Kumar wrote:
> Set map_queues in the fnic_host_template to fnic_mq_map_queues_cpus.
> Define fnic_mq_map_queues_cpus to set cpu assignment to
> fnic queues.
> Refactor code in fnic_probe to enable vnic queues before scsi_add_host.
> Modify notify set to the correct index.
>
> Changes between v2 and v3:
> Incorporate review comment from Hannes:
> Replace cpy_wq_base with copy_wq_base.
> Incorporate review comment from John Garry:
> Replace code in fnic_mq_map_queues_cpus
> with blk_mq_pci_map_queues.
> Replace shost_printk logs with FNIC_MAIN_DBG.

JFYI, This comment does not belong here ...

>
> Reviewed-by: Sesidhar Baddela <[email protected]>
> Reviewed-by: Arulprabhu Ponnusamy <[email protected]>
> Reviewed-by: Hannes Reinecke <[email protected]>
> Signed-off-by: Karan Tilak Kumar <[email protected]>
> ---

... should be placed here.



Regardless of a couple of comments, below, feel free to pick up:

Reviewed-by: John Garry <[email protected]>

> drivers/scsi/fnic/fnic.h | 4 +-
> drivers/scsi/fnic/fnic_main.c | 109 ++++++++++++++++++++++++----------
> 2 files changed, 78 insertions(+), 35 deletions(-)
>
> diff --git a/drivers/scsi/fnic/fnic.h b/drivers/scsi/fnic/fnic.h
> index 97a2e547584a..5777a54c99c3 100644
> --- a/drivers/scsi/fnic/fnic.h
> +++ b/drivers/scsi/fnic/fnic.h
> @@ -109,7 +109,7 @@ static inline u64 fnic_flags_and_state(struct scsi_cmnd *cmd)
> #define FNIC_ABT_TERM_DELAY_TIMEOUT 500 /* mSec */
>
> #define FNIC_MAX_FCP_TARGET 256
> -
> +#define FNIC_PCI_OFFSET 2
> /**
> * state_flags to identify host state along along with fnic's state
> **/
> @@ -384,7 +384,7 @@ void fnic_wq_copy_cleanup_handler(struct vnic_wq_copy *wq,
> int fnic_fw_reset_handler(struct fnic *fnic);
> void fnic_terminate_rport_io(struct fc_rport *);
> const char *fnic_state_to_str(unsigned int state);
> -
> +void fnic_mq_map_queues_cpus(struct Scsi_Host *host);
> void fnic_log_q_error(struct fnic *fnic);
> void fnic_handle_link_event(struct fnic *fnic);
>
> diff --git a/drivers/scsi/fnic/fnic_main.c b/drivers/scsi/fnic/fnic_main.c
> index 8bb0165490f4..93c457d88fc2 100644
> --- a/drivers/scsi/fnic/fnic_main.c
> +++ b/drivers/scsi/fnic/fnic_main.c
> @@ -12,9 +12,11 @@
> #include <linux/pci.h>
> #include <linux/skbuff.h>
> #include <linux/interrupt.h>
> +#include <linux/irq.h>
> #include <linux/spinlock.h>
> #include <linux/workqueue.h>
> #include <linux/if_ether.h>
> +#include <linux/blk-mq-pci.h>
> #include <scsi/fc/fc_fip.h>
> #include <scsi/scsi_host.h>
> #include <scsi/scsi_transport.h>
> @@ -116,6 +118,7 @@ static const struct scsi_host_template fnic_host_template = {
> .shost_groups = fnic_host_groups,
> .track_queue_depth = 1,
> .cmd_size = sizeof(struct fnic_cmd_priv),
> + .map_queues = fnic_mq_map_queues_cpus,
> };
>
> static void
> @@ -392,7 +395,7 @@ static int fnic_notify_set(struct fnic *fnic)
> err = vnic_dev_notify_set(fnic->vdev, -1);
> break;
> case VNIC_DEV_INTR_MODE_MSIX:
> - err = vnic_dev_notify_set(fnic->vdev, FNIC_MSIX_ERR_NOTIFY);
> + err = vnic_dev_notify_set(fnic->vdev, fnic->wq_copy_count + fnic->copy_wq_base);
> break;
> default:
> shost_printk(KERN_ERR, fnic->lport->host,
> @@ -565,11 +568,6 @@ static int fnic_scsi_drv_init(struct fnic *fnic)
> host->max_cmd_len = FCOE_MAX_CMD_LEN;
>
> host->nr_hw_queues = fnic->wq_copy_count;
> - if (host->nr_hw_queues > 1)
> - shost_printk(KERN_ERR, host,
> - "fnic: blk-mq is not supported");
> -
> - host->nr_hw_queues = fnic->wq_copy_count = 1;
>
> shost_printk(KERN_INFO, host,
> "fnic: can_queue: %d max_lun: %llu",
> @@ -582,15 +580,42 @@ static int fnic_scsi_drv_init(struct fnic *fnic)
> return 0;
> }
>
> +void fnic_mq_map_queues_cpus(struct Scsi_Host *host)
> +{
> + struct fc_lport *lp = shost_priv(host);
> + struct fnic *fnic = lport_priv(lp);
> + struct pci_dev *l_pdev = fnic->pdev;
> + int intr_mode = fnic->config.intr_mode;
> + struct blk_mq_queue_map *qmap = &host->tag_set.map[HCTX_TYPE_DEFAULT];
> +
> + if (intr_mode == VNIC_DEV_INTR_MODE_MSI || intr_mode == VNIC_DEV_INTR_MODE_INTX) {
> + FNIC_MAIN_DBG(KERN_ERR, fnic->lport->host, fnic->fnic_num,
> + "intr_mode is not msix\n");

Are these checks just paranoia? I mean that it is strange to have
fnic_mq_map_queues_cpus() called but not be required to do anything.

> + return;
> + }
> +
> + FNIC_MAIN_DBG(KERN_INFO, fnic->lport->host, fnic->fnic_num,
> + "qmap->nr_queues: %d\n", qmap->nr_queues);
> +
> + if (l_pdev == NULL) {
> + FNIC_MAIN_DBG(KERN_ERR, fnic->lport->host, fnic->fnic_num,
> + "l_pdev is null\n");
> + return;
> + }
> +
> + blk_mq_pci_map_queues(qmap, l_pdev, FNIC_PCI_OFFSET);
> +}
> +
> static int fnic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
> {
> struct Scsi_Host *host;
> struct fc_lport *lp;
> struct fnic *fnic;
> mempool_t *pool;
> - int err;
> + int err = 0;
> int i;
> unsigned long flags;
> + int hwq;
>
> atomic_inc(&fnic_num);
> /*
> @@ -607,8 +632,8 @@ static int fnic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
> fnic = lport_priv(lp);
> fnic->lport = lp;
> fnic->ctlr.lp = lp;
> -
> fnic->link_events = 0;
> + fnic->pdev = pdev;
>
> snprintf(fnic->name, sizeof(fnic->name) - 1, "%s%d", DRV_NAME,
> host->host_no);
> @@ -617,11 +642,6 @@ static int fnic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
> fnic->fnic_num = atomic_read(&fnic_num);
> fnic_stats_debugfs_init(fnic);
>
> - /* Setup PCI resources */
> - pci_set_drvdata(pdev, fnic);
> -
> - fnic->pdev = pdev;
> -
> err = pci_enable_device(pdev);
> if (err) {
> shost_printk(KERN_ERR, fnic->lport->host,
> @@ -723,7 +743,8 @@ static int fnic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
> goto err_out_dev_close;
> }
>
> - fnic_scsi_drv_init(fnic);
> + /* Setup PCI resources */
> + pci_set_drvdata(pdev, fnic);
>
> fnic_get_res_counts(fnic);
>
> @@ -743,6 +764,16 @@ static int fnic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
> goto err_out_clear_intr;
> }
>
> + fnic_scsi_drv_init(fnic);
> +
> + for (hwq = 0; hwq < fnic->wq_copy_count; hwq++) {
> + fnic->sw_copy_wq[hwq].ioreq_table_size = fnic->fnic_max_tag_id;
> + fnic->sw_copy_wq[hwq].io_req_table =
> + kzalloc((fnic->sw_copy_wq[hwq].ioreq_table_size + 1) *
> + sizeof(struct fnic_io_req *), GFP_KERNEL);
> + }
> + shost_printk(KERN_INFO, fnic->lport->host, "fnic copy wqs: %d, Q0 ioreq table size: %d\n",
> + fnic->wq_copy_count, fnic->sw_copy_wq[0].ioreq_table_size);
>
> /* initialize all fnic locks */
> spin_lock_init(&fnic->fnic_lock);
> @@ -827,16 +858,32 @@ static int fnic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
>
> /* allocate RQ buffers and post them to RQ*/
> for (i = 0; i < fnic->rq_count; i++) {
> - vnic_rq_enable(&fnic->rq[i]);
> err = vnic_rq_fill(&fnic->rq[i], fnic_alloc_rq_frame);
> if (err) {
> shost_printk(KERN_ERR, fnic->lport->host,
> "fnic_alloc_rq_frame can't alloc "
> "frame\n");
> - goto err_out_free_rq_buf;
> + goto err_out_rq_buf;
> }
> }
>
> + /* Enable all queues */
> + for (i = 0; i < fnic->raw_wq_count; i++)
> + vnic_wq_enable(&fnic->wq[i]);
> + for (i = 0; i < fnic->rq_count; i++) {
> + if (!ioread32(&fnic->rq[i].ctrl->enable))
> + vnic_rq_enable(&fnic->rq[i]);
> + }
> + for (i = 0; i < fnic->wq_copy_count; i++)
> + vnic_wq_copy_enable(&fnic->hw_copy_wq[i]);
> +
> + err = fnic_request_intr(fnic);
> + if (err) {
> + shost_printk(KERN_ERR, fnic->lport->host,
> + "Unable to request irq.\n");
> + goto err_out_request_intr;
> + }
> +
> /*
> * Initialization done with PCI system, hardware, firmware.
> * Add host to SCSI
> @@ -845,9 +892,10 @@ static int fnic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
> if (err) {
> shost_printk(KERN_ERR, fnic->lport->host,
> "fnic: scsi_add_host failed...exiting\n");
> - goto err_out_free_rq_buf;
> + goto err_out_scsi_add_host;
> }
>
> +
> /* Start local port initiatialization */
>
> lp->link_up = 0;
> @@ -871,7 +919,7 @@ static int fnic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
> if (!fc_exch_mgr_alloc(lp, FC_CLASS_3, FCPIO_HOST_EXCH_RANGE_START,
> FCPIO_HOST_EXCH_RANGE_END, NULL)) {
> err = -ENOMEM;
> - goto err_out_remove_scsi_host;
> + goto err_out_fc_exch_mgr_alloc;
> }
>
> fc_lport_init_stats(lp);
> @@ -899,21 +947,8 @@ static int fnic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
> skb_queue_head_init(&fnic->frame_queue);
> skb_queue_head_init(&fnic->tx_queue);
>
> - /* Enable all queues */
> - for (i = 0; i < fnic->raw_wq_count; i++)
> - vnic_wq_enable(&fnic->wq[i]);
> - for (i = 0; i < fnic->wq_copy_count; i++)
> - vnic_wq_copy_enable(&fnic->hw_copy_wq[i]);
> -
> fc_fabric_login(lp);
>
> - err = fnic_request_intr(fnic);
> - if (err) {
> - shost_printk(KERN_ERR, fnic->lport->host,
> - "Unable to request irq.\n");
> - goto err_out_free_exch_mgr;
> - }
> -
> vnic_dev_enable(fnic->vdev);
>
> for (i = 0; i < fnic->intr_count; i++)
> @@ -925,12 +960,15 @@ static int fnic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
>
> err_out_free_exch_mgr:
> fc_exch_mgr_free(lp);
> -err_out_remove_scsi_host:
> +err_out_fc_exch_mgr_alloc:
> fc_remove_host(lp->host);
> scsi_remove_host(lp->host);
> -err_out_free_rq_buf:
> +err_out_scsi_add_host:
> + fnic_free_intr(fnic);
> +err_out_request_intr:
> for (i = 0; i < fnic->rq_count; i++)
> vnic_rq_clean(&fnic->rq[i], fnic_free_rq_buf);
> +err_out_rq_buf:
> vnic_dev_notify_unset(fnic->vdev);
> err_out_free_max_pool:
> mempool_destroy(fnic->io_sgl_pool[FNIC_SGL_CACHE_MAX]);
> @@ -939,6 +977,8 @@ static int fnic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
> err_out_free_ioreq_pool:
> mempool_destroy(fnic->io_req_pool);
> err_out_free_resources:
> + for (hwq = 0; hwq < fnic->wq_copy_count; hwq++)
> + kfree(fnic->sw_copy_wq[hwq].io_req_table);
> fnic_free_vnic_resources(fnic);
> err_out_clear_intr:
> fnic_clear_intr_mode(fnic);
> @@ -965,6 +1005,7 @@ static void fnic_remove(struct pci_dev *pdev)
> struct fnic *fnic = pci_get_drvdata(pdev);
> struct fc_lport *lp = fnic->lport;
> unsigned long flags;
> + int hwq;
>
> /*
> * Mark state so that the workqueue thread stops forwarding
> @@ -1025,6 +1066,8 @@ static void fnic_remove(struct pci_dev *pdev)
>
> fc_remove_host(fnic->lport->host);
> scsi_remove_host(fnic->lport->host);
> + for (hwq = 0; hwq < fnic->wq_copy_count; hwq++)
> + kfree(fnic->sw_copy_wq[hwq].io_req_table);

you might be able to use device-managed methods for allocating this
memory, like devm_kzalloc() (so that the manual memory free'ing is not
required).

> fc_exch_mgr_free(fnic->lport);
> vnic_dev_notify_unset(fnic->vdev);
> fnic_free_intr(fnic);


Subject: RE: [PATCH v3 10/13] scsi: fnic: Add support for multiqueue (MQ) in fnic_main.c

On Wednesday, November 15, 2023 7:04 AM, John Garry <[email protected]> wrote:
>
> On 14/11/2023 22:38, Karan Tilak Kumar wrote:
> > Set map_queues in the fnic_host_template to fnic_mq_map_queues_cpus.
> > Define fnic_mq_map_queues_cpus to set cpu assignment to fnic queues.
> > Refactor code in fnic_probe to enable vnic queues before scsi_add_host.
> > Modify notify set to the correct index.
> >
> > Changes between v2 and v3:
> > Incorporate review comment from Hannes:
> > Replace cpy_wq_base with copy_wq_base.
> > Incorporate review comment from John Garry:
> > Replace code in fnic_mq_map_queues_cpus
> > with blk_mq_pci_map_queues.
> > Replace shost_printk logs with FNIC_MAIN_DBG.
>
> JFYI, This comment does not belong here ...
>
> >
> > Reviewed-by: Sesidhar Baddela <[email protected]>
> > Reviewed-by: Arulprabhu Ponnusamy <[email protected]>
> > Reviewed-by: Hannes Reinecke <[email protected]>
> > Signed-off-by: Karan Tilak Kumar <[email protected]>
> > ---
>
> ... should be placed here.

Thanks John. I'll keep this in mind for the next time.


> Regardless of a couple of comments, below, feel free to pick up:
>
> Reviewed-by: John Garry <[email protected]>
>

Thanks for your review.

> > +void fnic_mq_map_queues_cpus(struct Scsi_Host *host) {
> > + struct fc_lport *lp = shost_priv(host);
> > + struct fnic *fnic = lport_priv(lp);
> > + struct pci_dev *l_pdev = fnic->pdev;
> > + int intr_mode = fnic->config.intr_mode;
> > + struct blk_mq_queue_map *qmap =
> > +&host->tag_set.map[HCTX_TYPE_DEFAULT];
> > +
> > + if (intr_mode == VNIC_DEV_INTR_MODE_MSI || intr_mode == VNIC_DEV_INTR_MODE_INTX) {
> > + FNIC_MAIN_DBG(KERN_ERR, fnic->lport->host, fnic->fnic_num,
> > + "intr_mode is not msix\n");
>
> Are these checks just paranoia? I mean that it is strange to have
> fnic_mq_map_queues_cpus() called but not be required to do anything.
>

Unified Computing Servers Management (UCSM) is a GUI tool to configure Cisco Servers.
There are interrupt options that can be modified to INTX or MSI or MSI-x.
All these options are still supported.

However, we do not support multiqueue (MQ) on MSI or INTX.
These checks are present to only prevent an MQ "misconfiguration".

> > + for (hwq = 0; hwq < fnic->wq_copy_count; hwq++)
> > + kfree(fnic->sw_copy_wq[hwq].io_req_table);
>
> you might be able to use device-managed methods for allocating this memory, like devm_kzalloc() (so that the manual memory free'ing is not required).
>

Thanks for this information. We can consider this in a future patchset.

Regards,
Karan

2023-11-16 16:33:09

by John Garry

[permalink] [raw]
Subject: Re: [PATCH v3 10/13] scsi: fnic: Add support for multiqueue (MQ) in fnic_main.c

On 15/11/2023 23:20, Karan Tilak Kumar (kartilak) wrote:
>>> +
>>> + if (intr_mode == VNIC_DEV_INTR_MODE_MSI || intr_mode == VNIC_DEV_INTR_MODE_INTX) {
>>> + FNIC_MAIN_DBG(KERN_ERR, fnic->lport->host, fnic->fnic_num,
>>> + "intr_mode is not msix\n");
>> Are these checks just paranoia? I mean that it is strange to have
>> fnic_mq_map_queues_cpus() called but not be required to do anything.
>>
> Unified Computing Servers Management (UCSM) is a GUI tool to configure Cisco Servers.
> There are interrupt options that can be modified to INTX or MSI or MSI-x.
> All these options are still supported.
>
> However, we do not support multiqueue (MQ) on MSI or INTX.

By this I assume it means nr_hw_queues = 1 for MSI or INTX

> These checks are present to only prevent an MQ "misconfiguration".

If you check blk_mq_update_queue_map(), for set->ops->map_queues unset
we call blk_mq_map_queues() - I am just wondering what does the
equivalent to blk_mq_map_queues() for you in these other modes.

I am concerned that it is not proper that we have a set->ops->map_queues
method, but it does nothing in some scenarios.

Thanks,
John

2023-11-16 17:33:33

by John Garry

[permalink] [raw]
Subject: Re: [PATCH v3 10/13] scsi: fnic: Add support for multiqueue (MQ) in fnic_main.c

On 16/11/2023 16:32, John Garry wrote:
>
> If you check blk_mq_update_queue_map(), for set->ops->map_queues unset
> we call blk_mq_map_queues() - I am just wondering what does the
> equivalent to blk_mq_map_queues() for you in these other modes.
>
> I am concerned that it is not proper that we have a set->ops->map_queues
> method, but it does nothing in some scenarios.

I think we get away with this as mq_map[for all CPUs] is 0, which points
to the only HW queue.

Thanks,
John

Subject: RE: [PATCH v3 10/13] scsi: fnic: Add support for multiqueue (MQ) in fnic_main.c

On Thursday, November 16, 2023 8:33 AM, John Garry <[email protected]> wrote:
>
> On 15/11/2023 23:20, Karan Tilak Kumar (kartilak) wrote:
> >>> +
> >>> + if (intr_mode == VNIC_DEV_INTR_MODE_MSI || intr_mode == VNIC_DEV_INTR_MODE_INTX) {
> >>> + FNIC_MAIN_DBG(KERN_ERR, fnic->lport->host, fnic->fnic_num,
> >>> + "intr_mode is not msix\n");
> >> Are these checks just paranoia? I mean that it is strange to have
> >> fnic_mq_map_queues_cpus() called but not be required to do anything.
> >>
> > Unified Computing Servers Management (UCSM) is a GUI tool to configure Cisco Servers.
> > There are interrupt options that can be modified to INTX or MSI or MSI-x.
> > All these options are still supported.
> >
> > However, we do not support multiqueue (MQ) on MSI or INTX.
>
> By this I assume it means nr_hw_queues = 1 for MSI or INTX

That's correct, John.

> > These checks are present to only prevent an MQ "misconfiguration".
>
> > If you check blk_mq_update_queue_map(), for set->ops->map_queues unset we call blk_mq_map_queues() - I am just wondering what does the equivalent to blk_mq_map_queues() for you in these other modes.
>
> > I am concerned that it is not proper that we have a set->ops->map_queues method, but it does nothing in some scenarios.
>
> I think we get away with this as mq_map[for all CPUs] is 0, which points to the only HW queue.

Yes, that's correct. This is what I found during testing as well.

Regards,
Karan