From: Ming Lin <ming.l@xxxxxxxxxxxxxxx>
This adds nvme submission/completion queue handlers,
which are ported from qemu-nvme.
And hooks into nvme-target to do the real job.
Cc: Keith Busch <keith.busch@xxxxxxxxx>
Signed-off-by: Ming Lin <ming.l@xxxxxxxxxxxxxxx>
---
drivers/nvme/target/vhost.c | 420 +++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 416 insertions(+), 4 deletions(-)
diff --git a/drivers/nvme/target/vhost.c b/drivers/nvme/target/vhost.c
index 6847c86..3ce1348 100644
--- a/drivers/nvme/target/vhost.c
+++ b/drivers/nvme/target/vhost.c
@@ -6,10 +6,12 @@
#include <linux/mutex.h>
#include <linux/file.h>
#include <linux/highmem.h>
+#include <linux/kthread.h>
#include "../../vhost/vhost.h"
#include "nvmet.h"
#define NVMET_VHOST_AQ_DEPTH 256
+#define NVMET_VHOST_MAX_SEGMENTS 32
enum NvmeCcShift {
CC_MPS_SHIFT = 7,
@@ -52,6 +54,15 @@ struct nvmet_vhost_ctrl_eventfd {
int __user *vector;
};
+struct nvmet_vhost_iod {
+ struct nvmet_vhost_sq *sq;
+ struct scatterlist sg[NVMET_VHOST_MAX_SEGMENTS];
+ struct nvme_command cmd;
+ struct nvme_completion rsp;
+ struct nvmet_req req;
+ struct list_head entry;
+};
+
struct nvmet_vhost_cq {
struct nvmet_cq cq;
struct nvmet_vhost_ctrl *ctrl;
@@ -61,6 +72,12 @@ struct nvmet_vhost_cq {
u8 phase;
u64 dma_addr;
struct eventfd_ctx *eventfd;
+
+ struct list_head sq_list;
+ struct list_head req_list;
+ spinlock_t lock;
+ struct task_struct *thread;
+ int scheduled;
};
struct nvmet_vhost_sq {
@@ -71,6 +88,13 @@ struct nvmet_vhost_sq {
u32 tail;
u64 dma_addr;
u16 cqid;
+
+ struct nvmet_vhost_iod *io_req;
+ struct list_head req_list;
+ struct list_head entry;
+ struct mutex lock;
+ struct task_struct *thread;
+ int scheduled;
};
struct nvmet_vhost_ctrl {
@@ -191,13 +215,13 @@ static int nvmet_vhost_rw(struct vhost_dev *dev, u64 guest_pa,
return 0;
}
-int nvmet_vhost_read(struct vhost_dev *dev, u64 guest_pa,
+static int nvmet_vhost_read(struct vhost_dev *dev, u64 guest_pa,
void *buf, uint32_t size)
{
return nvmet_vhost_rw(dev, guest_pa, buf, size, 0);
}
-int nvmet_vhost_write(struct vhost_dev *dev, u64 guest_pa,
+static int nvmet_vhost_write(struct vhost_dev *dev, u64 guest_pa,
void *buf, uint32_t size)
{
return nvmet_vhost_rw(dev, guest_pa, buf, size, 1);
@@ -216,6 +240,289 @@ static int nvmet_vhost_check_cqid(struct nvmet_ctrl *n, u16 cqid)
return cqid <= n->subsys->max_qid && n->cqs[cqid] != NULL ? 0 : -1;
}
+static void nvmet_vhost_inc_cq_tail(struct nvmet_vhost_cq *cq)
+{
+ cq->tail++;
+ if (cq->tail >= cq->cq.size) {
+ cq->tail = 0;
+ cq->phase = !cq->phase;
+ }
+}
+
+static void nvmet_vhost_inc_sq_head(struct nvmet_vhost_sq *sq)
+{
+ sq->head = (sq->head + 1) % sq->sq.size;
+}
+
+static uint8_t nvmet_vhost_cq_full(struct nvmet_vhost_cq *cq)
+{
+ return (cq->tail + 1) % cq->cq.size == cq->head;
+}
+
+static uint8_t nvmet_vhost_sq_empty(struct nvmet_vhost_sq *sq)
+{
+ return sq->head == sq->tail;
+}
+
+static void nvmet_vhost_post_cqes(struct nvmet_vhost_cq *cq)
+{
+ struct nvmet_vhost_ctrl *n = cq->ctrl;
+ struct nvmet_vhost_iod *req;
+ struct list_head *p, *tmp;
+ int signal = 0;
+ unsigned long flags;
+
+ spin_lock_irqsave(&cq->lock, flags);
+ list_for_each_safe(p, tmp, &cq->req_list) {
+ struct nvmet_vhost_sq *sq;
+ u64 addr;
+
+ if (nvmet_vhost_cq_full(cq))
+ goto unlock;
+
+ req = list_entry(p, struct nvmet_vhost_iod, entry);
+ list_del(p);
+
+ sq = req->sq;
+ req->rsp.status |= cq->phase;
+ req->rsp.sq_id = cpu_to_le16(sq->sq.qid);
+ req->rsp.sq_head = cpu_to_le16(sq->head);
+ addr = cq->dma_addr + cq->tail * n->cqe_size;
+ nvmet_vhost_inc_cq_tail(cq);
+ spin_unlock_irqrestore(&cq->lock, flags);
+
+ nvmet_vhost_write(&n->dev, addr, (void *)&req->rsp,
+ sizeof(req->rsp));
+
+ mutex_lock(&sq->lock);
+ list_add_tail(p, &sq->req_list);
+ mutex_unlock(&sq->lock);
+
+ signal = 1;
+
+ spin_lock_irqsave(&cq->lock, flags);
+ }
+
+ if (signal)
+ eventfd_signal(cq->eventfd, 1);
+
+unlock:
+ cq->scheduled = 0;
+ spin_unlock_irqrestore(&cq->lock, flags);
+}
+
+static int nvmet_vhost_cq_thread(void *arg)
+{
+ struct nvmet_vhost_cq *sq = arg;
+
+ while (1) {
+ if (kthread_should_stop())
+ break;
+
+ nvmet_vhost_post_cqes(sq);
+
+ schedule();
+ }
+
+ return 0;
+}
+
+static void nvmet_vhost_enqueue_req_completion(
+ struct nvmet_vhost_cq *cq, struct nvmet_vhost_iod *iod)
+{
+ unsigned long flags;
+
+ BUG_ON(cq->cq.qid != iod->sq->sq.qid);
+ spin_lock_irqsave(&cq->lock, flags);
+ list_add_tail(&iod->entry, &cq->req_list);
+ if (!cq->scheduled) {
+ wake_up_process(cq->thread);
+ cq->scheduled = 1;
+ }
+ spin_unlock_irqrestore(&cq->lock, flags);
+}
+
+static void nvmet_vhost_queue_response(struct nvmet_req *req)
+{
+ struct nvmet_vhost_iod *iod =
+ container_of(req, struct nvmet_vhost_iod, req);
+ struct nvmet_vhost_sq *sq = iod->sq;
+ struct nvmet_vhost_ctrl *n = sq->ctrl;
+ struct nvmet_vhost_cq *cq = n->cqs[sq->sq.qid];
+
+ nvmet_vhost_enqueue_req_completion(cq, iod);
+}
+
+static int nvmet_vhost_sglist_add(struct nvmet_vhost_ctrl *n, struct scatterlist *sg,
+ u64 guest_addr, int len, int is_write)
+{
+ void __user *host_addr;
+ struct page *page;
+ unsigned int offset, nbytes;
+ int ret;
+
+ host_addr = map_guest_to_host(&n->dev, guest_addr, len);
+ if (unlikely(!host_addr)) {
+ pr_warn("cannot map guest addr %p, error %ld\n",
+ (void *)guest_addr, PTR_ERR(host_addr));
+ return PTR_ERR(host_addr);
+ }
+
+ ret = get_user_pages(current, n->dev.mm, (unsigned long)host_addr, 1,
+ is_write, 0, &page, NULL);
+ BUG_ON(ret == 0); /* we should either get our page or fail */
+ if (ret < 0) {
+ pr_warn("get_user_pages faild: host_addr %p, %d\n",
+ host_addr, ret);
+ return ret;
+ }
+
+ offset = (uintptr_t)host_addr & ~PAGE_MASK;
+ nbytes = min_t(unsigned int, PAGE_SIZE - offset, len);
+ sg_set_page(sg, page, nbytes, offset);
+
+ return 0;
+}
+
+static int nvmet_vhost_map_prp(struct nvmet_vhost_ctrl *n, struct scatterlist *sgl,
+ u64 prp1, u64 prp2, unsigned int len)
+{
+ unsigned int trans_len = n->page_size - (prp1 % n->page_size);
+ int num_prps = (len >> n->page_bits) + 1;
+ //FIXME
+ int is_write = 1;
+
+ trans_len = min(len, trans_len);
+ if (!prp1)
+ return -1;
+
+ sg_init_table(sgl, num_prps);
+
+ nvmet_vhost_sglist_add(n, sgl, prp1, trans_len, is_write);
+
+ len -= trans_len;
+ if (len) {
+ if (!prp2)
+ goto error;
+ if (len > n->page_size) {
+ u64 prp_list[n->max_prp_ents];
+ u16 nents, prp_trans;
+ int i = 0;
+
+ nents = (len + n->page_size - 1) >> n->page_bits;
+ prp_trans = min(n->max_prp_ents, nents) * sizeof(u64);
+ nvmet_vhost_read(&n->dev, prp2, (void *)prp_list, prp_trans);
+
+ while (len != 0) {
+ u64 prp_ent = le64_to_cpu(prp_list[i]);
+
+ if (i == n->max_prp_ents - 1 && len > n->page_size) {
+ if (!prp_ent || prp_ent & (n->page_size - 1))
+ goto error;
+ i = 0;
+ nents = (len + n->page_size - 1) >> n->page_bits;
+ prp_trans = min(n->max_prp_ents, nents) * sizeof(u64);
+ nvmet_vhost_read(&n->dev, prp_ent, (void *)prp_list, prp_trans);
+ prp_ent = le64_to_cpu(prp_list[i]);
+ }
+
+ if (!prp_ent || prp_ent & (n->page_size - 1))
+ goto error;
+
+ trans_len = min(len, n->page_size);
+ nvmet_vhost_sglist_add(n, sgl, prp_ent, trans_len, is_write);
+ sgl++;
+ len -= trans_len;
+ i++;
+ }
+ } else {
+ if (prp2 & (n->page_size - 1))
+ goto error;
+ nvmet_vhost_sglist_add(n, sgl, prp2, trans_len, is_write);
+ }
+ }
+
+ return num_prps;
+
+error:
+ return -1;
+}
+
+static void nvmet_vhost_process_sq(struct nvmet_vhost_sq *sq)
+{
+ struct nvmet_vhost_ctrl *n = sq->ctrl;
+ struct nvmet_vhost_cq *cq = n->cqs[sq->sq.qid];
+ struct nvmet_vhost_iod *iod;
+ struct nvme_command *cmd;
+ int ret;
+
+ mutex_lock(&sq->lock);
+
+ while (!(nvmet_vhost_sq_empty(sq) || list_empty(&sq->req_list))) {
+ u64 addr = sq->dma_addr + sq->head * n->sqe_size;;
+
+ nvmet_vhost_inc_sq_head(sq);
+ iod = list_first_entry(&sq->req_list,
+ struct nvmet_vhost_iod, entry);
+ list_del(&iod->entry);
+ mutex_unlock(&sq->lock);
+
+ cmd = &iod->cmd;
+ ret = nvmet_vhost_read(&n->dev, addr,
+ (void *)cmd, sizeof(*cmd));
+ if (ret) {
+ pr_warn("nvmet_vhost_read fail\n");
+ goto out;
+ }
+
+ ret = nvmet_req_init(&iod->req, &cq->cq, &sq->sq,
+ nvmet_vhost_queue_response);
+ if (ret) {
+ pr_warn("nvmet_req_init error: ret 0x%x, qid %d\n", ret, sq->sq.qid);
+ goto out;
+ }
+ if (iod->req.data_len) {
+ ret = nvmet_vhost_map_prp(n, iod->sg, cmd->common.prp1,
+ cmd->common.prp2, iod->req.data_len);
+ if (ret > 0) {
+ iod->req.sg = iod->sg;
+ iod->req.sg_cnt = ret;
+ } else {
+ pr_warn("map prp error\n");
+ goto out;
+ }
+ }
+ iod->req.execute(&iod->req);
+ mutex_lock(&sq->lock);
+ }
+
+unlock:
+ sq->scheduled = 0;
+ mutex_unlock(&sq->lock);
+ return;
+
+out:
+ mutex_lock(&sq->lock);
+ list_add_tail(&iod->entry, &sq->req_list);
+ goto unlock;
+}
+
+static int nvmet_vhost_sq_thread(void *opaque)
+{
+ struct nvmet_vhost_sq *sq = opaque;
+
+ while (1) {
+ if (kthread_should_stop())
+ break;
+
+ nvmet_vhost_process_sq(sq);
+
+ schedule();
+ }
+
+ return 0;
+}
+
static int nvmet_vhost_init_cq(struct nvmet_vhost_cq *cq,
struct nvmet_vhost_ctrl *n, u64 dma_addr,
u16 cqid, u16 size, struct eventfd_ctx *eventfd,
@@ -228,6 +535,12 @@ static int nvmet_vhost_init_cq(struct nvmet_vhost_cq *cq,
cq->eventfd = eventfd;
n->cqs[cqid] = cq;
+ spin_lock_init(&cq->lock);
+ INIT_LIST_HEAD(&cq->req_list);
+ INIT_LIST_HEAD(&cq->sq_list);
+ cq->scheduled = 0;
+ cq->thread = kthread_create(nvmet_vhost_cq_thread, cq, "nvmet_vhost_cq");
+
nvmet_cq_init(n->ctrl, &cq->cq, cqid, size);
return 0;
@@ -237,12 +550,36 @@ static int nvmet_vhost_init_sq(struct nvmet_vhost_sq *sq,
struct nvmet_vhost_ctrl *n, u64 dma_addr,
u16 sqid, u16 cqid, u16 size)
{
+ struct nvmet_vhost_cq *cq;
+ struct nvmet_vhost_iod *iod;
+ int i;
+
sq->ctrl = n;
sq->dma_addr = dma_addr;
sq->cqid = cqid;
sq->head = sq->tail = 0;
n->sqs[sqid] = sq;
+ mutex_init(&sq->lock);
+ INIT_LIST_HEAD(&sq->req_list);
+ sq->io_req = kmalloc(sizeof(struct nvmet_vhost_iod) * size, GFP_KERNEL);
+ if (!sq->io_req)
+ return -ENOMEM;
+ for (i = 0; i < size; i++) {
+ iod = &sq->io_req[i];
+
+ iod->req.cmd = &iod->cmd;
+ iod->req.rsp = &iod->rsp;
+ iod->sq = sq;
+ list_add_tail(&iod->entry, &sq->req_list);
+ }
+ sq->scheduled = 0;
+ sq->thread = kthread_create(nvmet_vhost_sq_thread, sq, "nvmet_vhost_sq");
+
+ cq = n->cqs[cqid];
+ list_add_tail(&sq->entry, &cq->sq_list);
+ n->sqs[sqid] = sq;
+
nvmet_sq_init(n->ctrl, &sq->sq, sqid, size);
return 0;
@@ -564,12 +901,84 @@ static int nvmet_bar_write(struct nvmet_vhost_ctrl *n, int offset, u64 val)
return status;
}
+static int nvmet_vhost_process_db(struct nvmet_ctrl *ctrl, int offset, u64 val)
+{
+ u16 qid;
+
+ if (offset & ((1 << 2) - 1))
+ return -EINVAL;
+
+ if (((offset - 0x1000) >> 2) & 1) {
+ u16 new_head = val & 0xffff;
+ int start_sqs;
+ struct nvmet_vhost_cq *vcq;
+ struct nvmet_cq *cq;
+ unsigned long flags;
+
+ qid = (offset - (0x1000 + (1 << 2))) >> 3;
+ if (nvmet_vhost_check_cqid(ctrl, qid))
+ return -EINVAL;
+
+ cq = ctrl->cqs[qid];
+ if (new_head >= cq->size)
+ return -EINVAL;
+
+ vcq = cq_to_vcq(cq);
+ spin_lock_irqsave(&vcq->lock, flags);
+ start_sqs = nvmet_vhost_cq_full(vcq) ? 1 : 0;
+ vcq->head = new_head;
+ spin_unlock_irqrestore(&vcq->lock, flags);
+ if (start_sqs) {
+ struct nvmet_vhost_sq *sq;
+ struct list_head *p;
+
+ list_for_each(p, &vcq->sq_list) {
+ sq = list_entry(p, struct nvmet_vhost_sq, entry);
+ if (!sq->scheduled) {
+ sq->scheduled = 1;
+ wake_up_process(sq->thread);
+ }
+ }
+ if (!vcq->scheduled) {
+ vcq->scheduled = 1;
+ wake_up_process(vcq->thread);
+ }
+ }
+
+ if (vcq->tail != vcq->head)
+ eventfd_signal(vcq->eventfd, 1);
+ } else {
+ struct nvmet_vhost_sq *vsq;
+ struct nvmet_sq *sq;
+ u16 new_tail = val & 0xffff;
+
+ qid = (offset - 0x1000) >> 3;
+ if (nvmet_vhost_check_sqid(ctrl, qid))
+ return -EINVAL;
+
+ sq = ctrl->sqs[qid];
+ if (new_tail >= sq->size)
+ return -ENOSPC;
+
+ vsq = sq_to_vsq(sq);
+ mutex_lock(&vsq->lock);
+ vsq->tail = new_tail;
+ if (!vsq->scheduled) {
+ vsq->scheduled = 1;
+ wake_up_process(vsq->thread);
+ }
+ mutex_unlock(&vsq->lock);
+ }
+
+ return 0;
+}
+
static int nvmet_vhost_bar_write(struct nvmet_vhost_ctrl *n, int offset, u64 val)
{
if (offset < 0x1000)
return nvmet_bar_write(n, offset, val);
-
- return -1;
+ else
+ return nvmet_vhost_process_db(n->ctrl, offset, val);
}
static int nvmet_vhost_ioc_bar(struct nvmet_vhost_ctrl *n, void __user *argp)
@@ -612,6 +1021,8 @@ static void nvme_free_sq(struct nvmet_vhost_sq *sq,
struct nvmet_vhost_ctrl *n)
{
n->sqs[sq->sq.qid] = NULL;
+ kthread_stop(sq->thread);
+ kfree(sq->io_req);
if (sq->sq.qid)
kfree(sq);
}
@@ -620,6 +1031,7 @@ static void nvme_free_cq(struct nvmet_vhost_cq *cq,
struct nvmet_vhost_ctrl *n)
{
n->cqs[cq->cq.qid] = NULL;
+ kthread_stop(cq->thread);
if (cq->cq.qid)
kfree(cq);
}
--
1.9.1
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