Commit c47c93fa authored by John Levon's avatar John Levon Committed by Tomasz Zawadzki
Browse files

nvmf/vfio-user: avoid handle_suppressed_irq() if not needed 



There's a non-zero cost to looking up the CQ; only call this function in
the poll path if we need to.

While here, we'll streamline the ctrlr-level check.

Signed-off-by: default avatarJohn Levon <john.levon@nutanix.com>
Change-Id: I6bf123f759fcd856196f6613cb6c7d0219550136
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/12660


Community-CI: Broadcom CI <spdk-ci.pdl@broadcom.com>
Community-CI: Mellanox Build Bot
Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarChangpeng Liu <changpeng.liu@intel.com>
Reviewed-by: default avatarRui Chang <rui.chang@arm.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
parent 5ab0f37f

lib/nvmf/vfio_user.c

+18 −17
Original line number Diff line number Diff line
@@ -393,6 +393,7 @@ struct nvmf_vfio_user_ctrlr { 
	uint64_t				shadow_doorbell_buffer;

	uint64_t				eventidx_buffer;



	bool					adaptive_irqs_enabled;

	bool					self_kick_requested;

};
@@ -1192,6 +1193,15 @@ nvmf_vfio_user_create(struct spdk_nvmf_transport_opts *opts) 
		vu_transport->transport_opts.disable_shadow_doorbells = true;

	}



	/*

	 * If we are in interrupt mode, we cannot support adaptive IRQs, as

	 * there is no guarantee the SQ poller will run subsequently to send

	 * pending IRQs.

	 */

	if (spdk_interrupt_mode_is_enabled()) {

		vu_transport->transport_opts.disable_adaptive_irq = true;

	}



	SPDK_DEBUGLOG(nvmf_vfio, "vfio_user transport: disable_mappable_bar0=%d\n",

		      vu_transport->transport_opts.disable_mappable_bar0);

	SPDK_DEBUGLOG(nvmf_vfio, "vfio_user transport: disable_adaptive_irq=%d\n",
@@ -1578,14 +1588,6 @@ static int 
handle_cmd_req(struct nvmf_vfio_user_ctrlr *ctrlr, struct spdk_nvme_cmd *cmd,

	       struct nvmf_vfio_user_sq *sq);



static inline int

adaptive_irq_enabled(struct nvmf_vfio_user_ctrlr *ctrlr, struct nvmf_vfio_user_cq *cq)

{

	return (!spdk_interrupt_mode_is_enabled() && cq->qid != 0 &&

		!ctrlr->transport->transport_opts.disable_adaptive_irq);



}



/*

 * Posts a CQE in the completion queue.

 *
@@ -1646,12 +1648,7 @@ post_completion(struct nvmf_vfio_user_ctrlr *ctrlr, struct nvmf_vfio_user_cq *cq 
	spdk_wmb();

	cq_tail_advance(cq);



	/*

	 * this function now executes at SPDK thread context, we

	 * might be triggering interrupts from vfio-user thread context so

	 * check for race conditions.

	 */

	if (!adaptive_irq_enabled(ctrlr, cq) &&

	if ((cq->qid == 0 || !ctrlr->adaptive_irqs_enabled) &&

	    cq->ien && ctrlr_interrupt_enabled(ctrlr)) {

		err = vfu_irq_trigger(ctrlr->endpoint->vfu_ctx, cq->iv);

		if (err != 0) {
@@ -4003,6 +4000,9 @@ nvmf_vfio_user_create_ctrlr(struct nvmf_vfio_user_transport *transport, 
	ctrlr->bar0_doorbells = endpoint->bar0_doorbells;

	TAILQ_INIT(&ctrlr->connected_sqs);



	ctrlr->adaptive_irqs_enabled =

		!transport->transport_opts.disable_adaptive_irq;



	/* Then, construct an admin queue pair */

	err = init_sq(ctrlr, &transport->transport, 0);

	if (err != 0) {
@@ -5131,8 +5131,7 @@ handle_suppressed_irq(struct nvmf_vfio_user_ctrlr *ctrlr, 
	uint32_t cq_head;

	uint32_t cq_tail;



	if (!cq->ien || !ctrlr_interrupt_enabled(ctrlr) ||

	    !adaptive_irq_enabled(ctrlr, cq)) {

	if (!cq->ien || cq->qid == 0 || !ctrlr_interrupt_enabled(ctrlr)) {

		return;

	}
@@ -5171,7 +5170,9 @@ nvmf_vfio_user_sq_poll(struct nvmf_vfio_user_sq *sq) 


	ctrlr = sq->ctrlr;



	if (ctrlr->adaptive_irqs_enabled) {

		handle_suppressed_irq(ctrlr, sq);

	}



	/* On aarch64 platforms, doorbells update from guest VM may not be seen

	 * on SPDK target side. This is because there is memory type mismatch