From 08a4f9bab348a490b17ca0ae334b7a2072e8809b Mon Sep 17 00:00:00 2001 From: Maxime Coquelin Date: Fri, 26 Jun 2020 16:04:36 +0200 Subject: [PATCH] vhost: use linked list for vDPA devices MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit There is no more notion of device ID outside of vdpa.c. We can now move from array to linked-list model for keeping track of the vDPA devices. There is no point in using array here, as all vDPA API are used from the control path, so no performance concerns. Signed-off-by: Maxime Coquelin Acked-by: Adrián Moreno --- lib/librte_vhost/rte_vdpa.h | 1 + lib/librte_vhost/vdpa.c | 134 +++++++++++++++++++----------------- 2 files changed, 70 insertions(+), 65 deletions(-) diff --git a/lib/librte_vhost/rte_vdpa.h b/lib/librte_vhost/rte_vdpa.h index da8ee33ab1..dbdc273702 100644 --- a/lib/librte_vhost/rte_vdpa.h +++ b/lib/librte_vhost/rte_vdpa.h @@ -105,6 +105,7 @@ struct rte_vdpa_dev_ops { * vdpa device structure includes device address and device operations. */ struct rte_vdpa_device { + TAILQ_ENTRY(rte_vdpa_device) next; /** Generic device information */ struct rte_device *device; /** vdpa device operations */ diff --git a/lib/librte_vhost/vdpa.c b/lib/librte_vhost/vdpa.c index bed20a3103..72561552c3 100644 --- a/lib/librte_vhost/vdpa.c +++ b/lib/librte_vhost/vdpa.c @@ -9,35 +9,54 @@ */ #include +#include #include #include +#include +#include + #include "rte_vdpa.h" #include "vhost.h" -static struct rte_vdpa_device vdpa_devices[MAX_VHOST_DEVICE]; +/** Double linked list of vDPA devices. */ +TAILQ_HEAD(vdpa_device_list, rte_vdpa_device); + +static struct vdpa_device_list vdpa_device_list = + TAILQ_HEAD_INITIALIZER(vdpa_device_list); +static rte_spinlock_t vdpa_device_list_lock = RTE_SPINLOCK_INITIALIZER; static uint32_t vdpa_device_num; -struct rte_vdpa_device * -rte_vdpa_find_device_by_name(const char *name) +/* Unsafe, needs to be called with vdpa_device_list_lock held */ +static struct rte_vdpa_device * +__vdpa_find_device_by_name(const char *name) { - struct rte_vdpa_device *dev; - int i; + struct rte_vdpa_device *dev, *ret = NULL; if (name == NULL) return NULL; - for (i = 0; i < MAX_VHOST_DEVICE; ++i) { - dev = &vdpa_devices[i]; - if (dev->ops == NULL) - continue; - - if (strncmp(dev->device->name, name, RTE_DEV_NAME_MAX_LEN) == 0) - return dev; + TAILQ_FOREACH(dev, &vdpa_device_list, next) { + if (!strncmp(dev->device->name, name, RTE_DEV_NAME_MAX_LEN)) { + ret = dev; + break; + } } - return NULL; + return ret; +} + +struct rte_vdpa_device * +rte_vdpa_find_device_by_name(const char *name) +{ + struct rte_vdpa_device *dev; + + rte_spinlock_lock(&vdpa_device_list_lock); + dev = __vdpa_find_device_by_name(name); + rte_spinlock_unlock(&vdpa_device_list_lock); + + return dev; } struct rte_device * @@ -54,52 +73,52 @@ rte_vdpa_register_device(struct rte_device *rte_dev, struct rte_vdpa_dev_ops *ops) { struct rte_vdpa_device *dev; - int i; - if (vdpa_device_num >= MAX_VHOST_DEVICE || ops == NULL) + if (ops == NULL) return NULL; - for (i = 0; i < MAX_VHOST_DEVICE; i++) { - dev = &vdpa_devices[i]; - if (dev->ops == NULL) - continue; - - if (dev->device == rte_dev) - return NULL; - } - - for (i = 0; i < MAX_VHOST_DEVICE; i++) { - if (vdpa_devices[i].ops == NULL) - break; + rte_spinlock_lock(&vdpa_device_list_lock); + /* Check the device hasn't been register already */ + dev = __vdpa_find_device_by_name(rte_dev->name); + if (dev) { + dev = NULL; + goto out_unlock; } - if (i == MAX_VHOST_DEVICE) - return NULL; + dev = rte_zmalloc(NULL, sizeof(*dev), 0); + if (!dev) + goto out_unlock; - dev = &vdpa_devices[i]; dev->device = rte_dev; dev->ops = ops; + TAILQ_INSERT_TAIL(&vdpa_device_list, dev, next); vdpa_device_num++; +out_unlock: + rte_spinlock_unlock(&vdpa_device_list_lock); return dev; } int -rte_vdpa_unregister_device(struct rte_vdpa_device *vdev) +rte_vdpa_unregister_device(struct rte_vdpa_device *dev) { - int i; + struct rte_vdpa_device *cur_dev, *tmp_dev; + int ret = -1; - for (i = 0; i < MAX_VHOST_DEVICE; i++) { - if (vdev != &vdpa_devices[i]) + rte_spinlock_lock(&vdpa_device_list_lock); + TAILQ_FOREACH_SAFE(cur_dev, &vdpa_device_list, next, tmp_dev) { + if (dev != cur_dev) continue; - memset(vdev, 0, sizeof(struct rte_vdpa_device)); + TAILQ_REMOVE(&vdpa_device_list, dev, next); + rte_free(dev); vdpa_device_num--; - - return 0; + ret = 0; + break; } + rte_spinlock_unlock(&vdpa_device_list_lock); - return -1; + return ret; } int @@ -246,19 +265,6 @@ rte_vdpa_reset_stats(struct rte_vdpa_device *dev, uint16_t qid) return dev->ops->reset_stats(dev, qid); } -static uint16_t -vdpa_dev_to_id(const struct rte_vdpa_device *dev) -{ - if (dev == NULL) - return MAX_VHOST_DEVICE; - - if (dev < &vdpa_devices[0] || - dev >= &vdpa_devices[MAX_VHOST_DEVICE]) - return MAX_VHOST_DEVICE; - - return (uint16_t)(dev - vdpa_devices); -} - static int vdpa_dev_match(struct rte_vdpa_device *dev, const struct rte_device *rte_dev) @@ -278,24 +284,22 @@ vdpa_find_device(const struct rte_vdpa_device *start, rte_vdpa_cmp_t cmp, struct rte_device *rte_dev) { struct rte_vdpa_device *dev; - uint16_t idx; - if (start != NULL) - idx = vdpa_dev_to_id(start) + 1; + rte_spinlock_lock(&vdpa_device_list_lock); + if (start == NULL) + dev = TAILQ_FIRST(&vdpa_device_list); else - idx = 0; - for (; idx < MAX_VHOST_DEVICE; idx++) { - dev = &vdpa_devices[idx]; - /* - * ToDo: Certainly better to introduce a state field, - * but rely on ops being set for now. - */ - if (dev->ops == NULL) - continue; + dev = TAILQ_NEXT(start, next); + + while (dev != NULL) { if (cmp(dev, rte_dev) == 0) - return dev; + break; + + dev = TAILQ_NEXT(dev, next); } - return NULL; + rte_spinlock_unlock(&vdpa_device_list_lock); + + return dev; } static void * -- 2.20.1