From f8f6ece36222bf4c7e9d4ce967eb2f9d33995670 Mon Sep 17 00:00:00 2001 From: Sasha Levin Date: Wed, 2 Nov 2011 07:41:11 +0200 Subject: [PATCH] kvm tools: Split io request from completion This patch splits IO request processing from completion notification. Signed-off-by: Sasha Levin Signed-off-by: Pekka Enberg --- tools/kvm/disk/core.c | 6 +- tools/kvm/include/kvm/disk-image.h | 4 +- tools/kvm/include/kvm/virtio-blk.h | 1 + tools/kvm/virtio/blk.c | 111 +++++++++++++++++++---------- 4 files changed, 81 insertions(+), 41 deletions(-) diff --git a/tools/kvm/disk/core.c b/tools/kvm/disk/core.c index c1cb52f0b690..a5e671391b29 100644 --- a/tools/kvm/disk/core.c +++ b/tools/kvm/disk/core.c @@ -152,7 +152,7 @@ ssize_t disk_image__read(struct disk_image *disk, u64 sector, const struct iovec } if (disk->disk_req_cb) - disk->disk_req_cb(param); + disk->disk_req_cb(param, total); return total; } @@ -184,7 +184,7 @@ ssize_t disk_image__write(struct disk_image *disk, u64 sector, const struct iove } if (disk->disk_req_cb) - disk->disk_req_cb(param); + disk->disk_req_cb(param, total); return total; } @@ -200,7 +200,7 @@ ssize_t disk_image__get_serial(struct disk_image *disk, void *buffer, ssize_t *l return *len; } -void disk_image__set_callback(struct disk_image *disk, void (*disk_req_cb)(void *param)) +void disk_image__set_callback(struct disk_image *disk, void (*disk_req_cb)(void *param, long len)) { disk->disk_req_cb = disk_req_cb; } diff --git a/tools/kvm/include/kvm/disk-image.h b/tools/kvm/include/kvm/disk-image.h index f22213fa21e8..632e54dc013e 100644 --- a/tools/kvm/include/kvm/disk-image.h +++ b/tools/kvm/include/kvm/disk-image.h @@ -45,7 +45,7 @@ struct disk_image { struct disk_image_operations *ops; void *priv; void *disk_req_cb_param; - void (*disk_req_cb)(void *param); + void (*disk_req_cb)(void *param, long len); }; struct disk_image *disk_image__open(const char *filename, bool readonly); @@ -72,5 +72,5 @@ ssize_t raw_image__read_sector_mmap(struct disk_image *disk, u64 sector, ssize_t raw_image__write_sector_mmap(struct disk_image *disk, u64 sector, const struct iovec *iov, int iovcount, void *param); int raw_image__close(struct disk_image *disk); -void disk_image__set_callback(struct disk_image *disk, void (*disk_req_cb)(void *param)); +void disk_image__set_callback(struct disk_image *disk, void (*disk_req_cb)(void *param, long len)); #endif /* KVM__DISK_IMAGE_H */ diff --git a/tools/kvm/include/kvm/virtio-blk.h b/tools/kvm/include/kvm/virtio-blk.h index 8c4fb9199177..63731a9bac7a 100644 --- a/tools/kvm/include/kvm/virtio-blk.h +++ b/tools/kvm/include/kvm/virtio-blk.h @@ -8,5 +8,6 @@ struct kvm; void virtio_blk__init(struct kvm *kvm, struct disk_image *disk); void virtio_blk__init_all(struct kvm *kvm); void virtio_blk__delete_all(struct kvm *kvm); +void virtio_blk_complete(void *param, long len); #endif /* KVM__BLK_VIRTIO_H */ diff --git a/tools/kvm/virtio/blk.c b/tools/kvm/virtio/blk.c index 9db293e4e57e..be53111a32dd 100644 --- a/tools/kvm/virtio/blk.c +++ b/tools/kvm/virtio/blk.c @@ -29,17 +29,21 @@ */ #define DISK_SEG_MAX (VIRTIO_BLK_QUEUE_SIZE - 2) -struct blk_dev_job { +struct blk_dev_req { + struct list_head list; struct virt_queue *vq; struct blk_dev *bdev; struct iovec iov[VIRTIO_BLK_QUEUE_SIZE]; u16 out, in, head; - struct thread_pool__job job_id; + struct kvm *kvm; }; struct blk_dev { pthread_mutex_t mutex; + pthread_mutex_t req_mutex; + struct list_head list; + struct list_head req_list; struct virtio_pci vpci; struct virtio_blk_config blk_config; @@ -47,41 +51,78 @@ struct blk_dev { u32 features; struct virt_queue vqs[NUM_VIRT_QUEUES]; - struct blk_dev_job jobs[VIRTIO_BLK_QUEUE_SIZE]; - u16 job_idx; + struct blk_dev_req reqs[VIRTIO_BLK_QUEUE_SIZE]; }; static LIST_HEAD(bdevs); static int compat_id; -static void virtio_blk_do_io_request(struct kvm *kvm, void *param) +static struct blk_dev_req *virtio_blk_req_pop(struct blk_dev *bdev) +{ + struct blk_dev_req *req = NULL; + + mutex_lock(&bdev->req_mutex); + if (!list_empty(&bdev->req_list)) { + req = list_first_entry(&bdev->req_list, struct blk_dev_req, list); + list_del_init(&req->list); + } + mutex_unlock(&bdev->req_mutex); + + return req; +} + +static void virtio_blk_req_push(struct blk_dev *bdev, struct blk_dev_req *req) +{ + mutex_lock(&bdev->req_mutex); + list_add(&req->list, &bdev->req_list); + mutex_unlock(&bdev->req_mutex); +} + +void virtio_blk_complete(void *param, long len) { - struct virtio_blk_outhdr *req; + struct blk_dev_req *req = param; + struct blk_dev *bdev = req->bdev; + int queueid = req->vq - bdev->vqs; u8 *status; + + /* status */ + status = req->iov[req->out + req->in - 1].iov_base; + *status = (len < 0) ? VIRTIO_BLK_S_IOERR : VIRTIO_BLK_S_OK; + + mutex_lock(&bdev->mutex); + virt_queue__set_used_elem(req->vq, req->head, len); + mutex_unlock(&bdev->mutex); + + virtio_pci__signal_vq(req->kvm, &bdev->vpci, queueid); + + virtio_blk_req_push(req->bdev, req); +} + +static void virtio_blk_do_io_request(struct kvm *kvm, struct blk_dev_req *req) +{ + struct virtio_blk_outhdr *req_hdr; ssize_t block_cnt; - struct blk_dev_job *job; struct blk_dev *bdev; struct virt_queue *queue; struct iovec *iov; u16 out, in, head; block_cnt = -1; - job = param; - bdev = job->bdev; - queue = job->vq; - iov = job->iov; - out = job->out; - in = job->in; - head = job->head; - req = iov[0].iov_base; - - switch (req->type) { + bdev = req->bdev; + queue = req->vq; + iov = req->iov; + out = req->out; + in = req->in; + head = req->head; + req_hdr = iov[0].iov_base; + + switch (req_hdr->type) { case VIRTIO_BLK_T_IN: - block_cnt = disk_image__read(bdev->disk, req->sector, iov + 1, + block_cnt = disk_image__read(bdev->disk, req_hdr->sector, iov + 1, in + out - 2, NULL); break; case VIRTIO_BLK_T_OUT: - block_cnt = disk_image__write(bdev->disk, req->sector, iov + 1, + block_cnt = disk_image__write(bdev->disk, req_hdr->sector, iov + 1, in + out - 2, NULL); break; case VIRTIO_BLK_T_FLUSH: @@ -92,35 +133,27 @@ static void virtio_blk_do_io_request(struct kvm *kvm, void *param) disk_image__get_serial(bdev->disk, (iov + 1)->iov_base, &block_cnt); break; default: - pr_warning("request type %d", req->type); + pr_warning("request type %d", req_hdr->type); block_cnt = -1; break; } - /* status */ - status = iov[out + in - 1].iov_base; - *status = (block_cnt < 0) ? VIRTIO_BLK_S_IOERR : VIRTIO_BLK_S_OK; - - mutex_lock(&bdev->mutex); - virt_queue__set_used_elem(queue, head, block_cnt); - mutex_unlock(&bdev->mutex); - - virtio_pci__signal_vq(kvm, &bdev->vpci, queue - bdev->vqs); + virtio_blk_complete(req, block_cnt); } static void virtio_blk_do_io(struct kvm *kvm, struct virt_queue *vq, struct blk_dev *bdev) { while (virt_queue__available(vq)) { - struct blk_dev_job *job = &bdev->jobs[bdev->job_idx++ % VIRTIO_BLK_QUEUE_SIZE]; + struct blk_dev_req *req = virtio_blk_req_pop(bdev); - *job = (struct blk_dev_job) { - .vq = vq, - .bdev = bdev, + *req = (struct blk_dev_req) { + .vq = vq, + .bdev = bdev, + .kvm = kvm, }; - job->head = virt_queue__get_iov(vq, job->iov, &job->out, &job->in, kvm); + req->head = virt_queue__get_iov(vq, req->iov, &req->out, &req->in, kvm); - thread_pool__init_job(&job->job_id, kvm, virtio_blk_do_io_request, job); - thread_pool__do_job(&job->job_id); + virtio_blk_do_io_request(kvm, req); } } @@ -191,6 +224,7 @@ static int get_size_vq(struct kvm *kvm, void *dev, u32 vq) void virtio_blk__init(struct kvm *kvm, struct disk_image *disk) { struct blk_dev *bdev; + size_t i; if (!disk) return; @@ -201,6 +235,7 @@ void virtio_blk__init(struct kvm *kvm, struct disk_image *disk) *bdev = (struct blk_dev) { .mutex = PTHREAD_MUTEX_INITIALIZER, + .req_mutex = PTHREAD_MUTEX_INITIALIZER, .disk = disk, .blk_config = (struct virtio_blk_config) { .capacity = disk->size / SECTOR_SIZE, @@ -222,6 +257,10 @@ void virtio_blk__init(struct kvm *kvm, struct disk_image *disk) list_add_tail(&bdev->list, &bdevs); + INIT_LIST_HEAD(&bdev->req_list); + for (i = 0; i < ARRAY_SIZE(bdev->reqs); i++) + list_add(&bdev->reqs[i].list, &bdev->req_list); + if (compat_id != -1) compat_id = compat__add_message("virtio-blk device was not detected", "While you have requested a virtio-blk device, " -- 2.39.5