Commit eb0305e0 authored by Thanos Makatos's avatar Thanos Makatos Committed by Tomasz Zawadzki
Browse files

nvmf/vfio-user: re-check doorbells upon resuming 



If we're in interrupt mode and live migrating a guest, there is a window
where the I/O queues haven't been set up but the device is in running
state, during which the guest might write to a doorbell. This doorbell
write will go unnoticed. This patch ensures that we re-check the
doorbells after an I/O queue has been set up.

Fixes #2410

Signed-off-by: default avatarThanos Makatos <thanos.makatos@nutanix.com>
Signed-off-by: default avatarJohn Levon <john.levon@nutanix.com>
Change-Id: I161d2a0e7ab3065022b2bccbe17f019640cceeba
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/11809


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 avatarJim Harris <james.r.harris@intel.com>
parent f3950cf4

lib/nvmf/vfio_user.c

+53 −4
Original line number Diff line number Diff line
@@ -349,6 +349,8 @@ struct nvmf_vfio_user_ctrlr { 
	TAILQ_ENTRY(nvmf_vfio_user_ctrlr)	link;



	volatile uint32_t			*doorbells;



	bool					self_kick_requested;

};



struct nvmf_vfio_user_endpoint {
@@ -497,6 +499,38 @@ vfio_user_migr_data_len(void) 
	return SPDK_ALIGN_CEIL(sizeof(struct vfio_user_nvme_migr_state), PAGE_SIZE);

}



static int

vfio_user_handle_intr(void *ctx);



/*

 * Wrap vfio_user_handle_intr() such that it can be used with

 * spdk_thread_send_msg().

 * Pollers have type int (*)(void *) while message functions should have type

 * void (*)(void *), so simply discard the returned value.

 */

static void

vfio_user_handle_intr_wrapper(void *ctx)

{

	vfio_user_handle_intr(ctx);

}



static inline int

self_kick(struct nvmf_vfio_user_ctrlr *ctrlr)

{

	assert(ctrlr != NULL);

	assert(ctrlr->thread != NULL);



	if (ctrlr->self_kick_requested) {

		return 0;

	}



	ctrlr->self_kick_requested = true;



	return spdk_thread_send_msg(ctrlr->thread,

				    vfio_user_handle_intr_wrapper,

				    ctrlr);

}



static int

nvme_cmd_map_prps(void *prv, struct spdk_nvme_cmd *cmd, struct iovec *iovs,

		  uint32_t max_iovcnt, uint32_t len, size_t mps,
@@ -3550,6 +3584,13 @@ nvmf_vfio_user_poll_group_create(struct spdk_nvmf_transport *transport, 
	return &vu_group->group;

}



static bool

in_interrupt_mode(struct nvmf_vfio_user_transport *vu_transport)

{

	return spdk_interrupt_mode_is_enabled() &&

	       vu_transport->intr_mode_supported;

}



static struct spdk_nvmf_transport_poll_group *

nvmf_vfio_user_get_optimal_poll_group(struct spdk_nvmf_qpair *qpair)

{
@@ -3586,8 +3627,7 @@ nvmf_vfio_user_get_optimal_poll_group(struct spdk_nvmf_qpair *qpair) 
		 * on the same poll group, to avoid complications in

		 * vfio_user_handle_intr().

		 */

		if (spdk_interrupt_mode_is_enabled() &&

		    vu_transport->intr_mode_supported) {

		if (in_interrupt_mode(vu_transport)) {

			result = sq->ctrlr->sqs[0]->group;

			goto out;

		}
@@ -3746,6 +3786,8 @@ vfio_user_handle_intr(void *ctx) 
	assert(ctrlr->sqs[0] != NULL);

	assert(ctrlr->sqs[0]->group != NULL);



	ctrlr->self_kick_requested = false;



	vfio_user_poll_vfu_ctx(ctrlr);



	/*
@@ -3797,8 +3839,7 @@ handle_queue_connect_rsp(struct nvmf_vfio_user_req *req, void *cb_arg) 


		cq->thread = spdk_get_thread();



		if (spdk_interrupt_mode_is_enabled() &&

		    endpoint->transport->intr_mode_supported) {

		if (in_interrupt_mode(endpoint->transport)) {

			vu_ctrlr->intr_fd = vfu_get_poll_fd(vu_ctrlr->endpoint->vfu_ctx);

			assert(vu_ctrlr->intr_fd != -1);
@@ -3840,6 +3881,14 @@ handle_queue_connect_rsp(struct nvmf_vfio_user_req *req, void *cb_arg) 
						sq->create_io_sq_cmd.cid, SPDK_NVME_SC_SUCCESS, SPDK_NVME_SCT_GENERIC);

			}

			sq->post_create_io_sq_completion = false;

		} else if (in_interrupt_mode(endpoint->transport)) {

			/*

			 * FIXME self_kick() ends up polling all queues on the

			 * controller thread, and this will be wrong if we ever

			 * support interrupt mode with I/O queues in a

			 * different poll group than the controller's.

			 */

			self_kick(vu_ctrlr);

		}

		sq->sq_state = VFIO_USER_SQ_ACTIVE;

	}