From: Jason Wang <jasowang@redhat.com>
To: mst@redhat.com, jasowang@redhat.com
Cc: kvm@vger.kernel.org, virtualization@lists.linux-foundation.org,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
jfreimann@redhat.com, tiwei.bie@intel.com,
maxime.coquelin@redhat.com
Subject: [PATCH V3 01/15] vhost: simplify meta data pointer accessing
Date: Wed, 17 Jul 2019 06:52:41 -0400 [thread overview]
Message-ID: <20190717105255.63488-2-jasowang@redhat.com> (raw)
In-Reply-To: <20190717105255.63488-1-jasowang@redhat.com>
Instead of open coding meta pointer accessing through caches. This
patch introduces vhost_get_meta_ptr()/vhost_put_meta_ptr() pair to
reduce the code duplication and simplify its callers
implementation. This is helpful for reducing LOC for packed virtqueue
as well.
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/vhost/vhost.c | 207 ++++++++++++++----------------------------
1 file changed, 70 insertions(+), 137 deletions(-)
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index dc9301d31f12..7f51c74d9aee 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -1194,25 +1194,37 @@ static inline void __user *__vhost_get_user(struct vhost_virtqueue *vq,
ret; \
})
-static inline int vhost_put_avail_event(struct vhost_virtqueue *vq)
-{
#if VHOST_ARCH_CAN_ACCEL_UACCESS
+static void *vhost_get_meta_ptr(struct vhost_virtqueue *vq, int type)
+{
struct vhost_map *map;
- struct vring_used *used;
if (!vq->iotlb) {
rcu_read_lock();
+ map = rcu_dereference(vq->maps[type]);
+ if (likely(map))
+ return map->addr;
+ rcu_read_unlock();
+ }
+ return NULL;
+}
- map = rcu_dereference(vq->maps[VHOST_ADDR_USED]);
- if (likely(map)) {
- used = map->addr;
- *((__virtio16 *)&used->ring[vq->num]) =
- cpu_to_vhost16(vq, vq->avail_idx);
- rcu_read_unlock();
- return 0;
- }
+static void vhost_put_meta_ptr(void)
+{
+ rcu_read_unlock();
+}
+#endif
- rcu_read_unlock();
+static inline int vhost_put_avail_event(struct vhost_virtqueue *vq)
+{
+#if VHOST_ARCH_CAN_ACCEL_UACCESS
+ struct vring_used *used = vhost_get_meta_ptr(vq, VHOST_ADDR_USED);
+
+ if (likely(used)) {
+ *((__virtio16 *)&used->ring[vq->num]) =
+ cpu_to_vhost16(vq, vq->avail_idx);
+ vhost_put_meta_ptr();
+ return 0;
}
#endif
@@ -1225,23 +1237,14 @@ static inline int vhost_put_used(struct vhost_virtqueue *vq,
int count)
{
#if VHOST_ARCH_CAN_ACCEL_UACCESS
- struct vhost_map *map;
- struct vring_used *used;
+ struct vring_used *used = vhost_get_meta_ptr(vq, VHOST_ADDR_USED);
size_t size;
- if (!vq->iotlb) {
- rcu_read_lock();
-
- map = rcu_dereference(vq->maps[VHOST_ADDR_USED]);
- if (likely(map)) {
- used = map->addr;
- size = count * sizeof(*head);
- memcpy(used->ring + idx, head, size);
- rcu_read_unlock();
- return 0;
- }
-
- rcu_read_unlock();
+ if (likely(used)) {
+ size = count * sizeof(*head);
+ memcpy(used->ring + idx, head, size);
+ vhost_put_meta_ptr();
+ return 0;
}
#endif
@@ -1253,21 +1256,12 @@ static inline int vhost_put_used_flags(struct vhost_virtqueue *vq)
{
#if VHOST_ARCH_CAN_ACCEL_UACCESS
- struct vhost_map *map;
- struct vring_used *used;
-
- if (!vq->iotlb) {
- rcu_read_lock();
+ struct vring_used *used = vhost_get_meta_ptr(vq, VHOST_ADDR_USED);
- map = rcu_dereference(vq->maps[VHOST_ADDR_USED]);
- if (likely(map)) {
- used = map->addr;
- used->flags = cpu_to_vhost16(vq, vq->used_flags);
- rcu_read_unlock();
- return 0;
- }
-
- rcu_read_unlock();
+ if (likely(used)) {
+ used->flags = cpu_to_vhost16(vq, vq->used_flags);
+ vhost_put_meta_ptr();
+ return 0;
}
#endif
@@ -1279,21 +1273,12 @@ static inline int vhost_put_used_idx(struct vhost_virtqueue *vq)
{
#if VHOST_ARCH_CAN_ACCEL_UACCESS
- struct vhost_map *map;
- struct vring_used *used;
+ struct vring_used *used = vhost_get_meta_ptr(vq, VHOST_ADDR_USED);
- if (!vq->iotlb) {
- rcu_read_lock();
-
- map = rcu_dereference(vq->maps[VHOST_ADDR_USED]);
- if (likely(map)) {
- used = map->addr;
- used->idx = cpu_to_vhost16(vq, vq->last_used_idx);
- rcu_read_unlock();
- return 0;
- }
-
- rcu_read_unlock();
+ if (likely(used)) {
+ used->idx = cpu_to_vhost16(vq, vq->last_used_idx);
+ vhost_put_meta_ptr();
+ return 0;
}
#endif
@@ -1343,21 +1328,12 @@ static inline int vhost_get_avail_idx(struct vhost_virtqueue *vq,
__virtio16 *idx)
{
#if VHOST_ARCH_CAN_ACCEL_UACCESS
- struct vhost_map *map;
- struct vring_avail *avail;
-
- if (!vq->iotlb) {
- rcu_read_lock();
+ struct vring_avail *avail = vhost_get_meta_ptr(vq, VHOST_ADDR_AVAIL);
- map = rcu_dereference(vq->maps[VHOST_ADDR_AVAIL]);
- if (likely(map)) {
- avail = map->addr;
- *idx = avail->idx;
- rcu_read_unlock();
- return 0;
- }
-
- rcu_read_unlock();
+ if (likely(avail)) {
+ *idx = avail->idx;
+ vhost_put_meta_ptr();
+ return 0;
}
#endif
@@ -1368,21 +1344,12 @@ static inline int vhost_get_avail_head(struct vhost_virtqueue *vq,
__virtio16 *head, int idx)
{
#if VHOST_ARCH_CAN_ACCEL_UACCESS
- struct vhost_map *map;
- struct vring_avail *avail;
-
- if (!vq->iotlb) {
- rcu_read_lock();
-
- map = rcu_dereference(vq->maps[VHOST_ADDR_AVAIL]);
- if (likely(map)) {
- avail = map->addr;
- *head = avail->ring[idx & (vq->num - 1)];
- rcu_read_unlock();
- return 0;
- }
+ struct vring_avail *avail = vhost_get_meta_ptr(vq, VHOST_ADDR_AVAIL);
- rcu_read_unlock();
+ if (likely(avail)) {
+ *head = avail->ring[idx & (vq->num - 1)];
+ vhost_put_meta_ptr();
+ return 0;
}
#endif
@@ -1394,21 +1361,12 @@ static inline int vhost_get_avail_flags(struct vhost_virtqueue *vq,
__virtio16 *flags)
{
#if VHOST_ARCH_CAN_ACCEL_UACCESS
- struct vhost_map *map;
- struct vring_avail *avail;
-
- if (!vq->iotlb) {
- rcu_read_lock();
+ struct vring_avail *avail = vhost_get_meta_ptr(vq, VHOST_ADDR_AVAIL);
- map = rcu_dereference(vq->maps[VHOST_ADDR_AVAIL]);
- if (likely(map)) {
- avail = map->addr;
- *flags = avail->flags;
- rcu_read_unlock();
- return 0;
- }
-
- rcu_read_unlock();
+ if (likely(avail)) {
+ *flags = avail->flags;
+ vhost_put_meta_ptr();
+ return 0;
}
#endif
@@ -1419,19 +1377,12 @@ static inline int vhost_get_used_event(struct vhost_virtqueue *vq,
__virtio16 *event)
{
#if VHOST_ARCH_CAN_ACCEL_UACCESS
- struct vhost_map *map;
- struct vring_avail *avail;
+ struct vring_avail *avail = vhost_get_meta_ptr(vq, VHOST_ADDR_AVAIL);
- if (!vq->iotlb) {
- rcu_read_lock();
- map = rcu_dereference(vq->maps[VHOST_ADDR_AVAIL]);
- if (likely(map)) {
- avail = map->addr;
- *event = (__virtio16)avail->ring[vq->num];
- rcu_read_unlock();
- return 0;
- }
- rcu_read_unlock();
+ if (likely(avail)) {
+ *event = (__virtio16)avail->ring[vq->num];
+ vhost_put_meta_ptr();
+ return 0;
}
#endif
@@ -1442,21 +1393,12 @@ static inline int vhost_get_used_idx(struct vhost_virtqueue *vq,
__virtio16 *idx)
{
#if VHOST_ARCH_CAN_ACCEL_UACCESS
- struct vhost_map *map;
- struct vring_used *used;
-
- if (!vq->iotlb) {
- rcu_read_lock();
-
- map = rcu_dereference(vq->maps[VHOST_ADDR_USED]);
- if (likely(map)) {
- used = map->addr;
- *idx = used->idx;
- rcu_read_unlock();
- return 0;
- }
+ struct vring_used *used = vhost_get_meta_ptr(vq, VHOST_ADDR_USED);
- rcu_read_unlock();
+ if (likely(used)) {
+ *idx = used->idx;
+ vhost_put_meta_ptr();
+ return 0;
}
#endif
@@ -1467,21 +1409,12 @@ static inline int vhost_get_desc(struct vhost_virtqueue *vq,
struct vring_desc *desc, int idx)
{
#if VHOST_ARCH_CAN_ACCEL_UACCESS
- struct vhost_map *map;
- struct vring_desc *d;
-
- if (!vq->iotlb) {
- rcu_read_lock();
-
- map = rcu_dereference(vq->maps[VHOST_ADDR_DESC]);
- if (likely(map)) {
- d = map->addr;
- *desc = *(d + idx);
- rcu_read_unlock();
- return 0;
- }
+ struct vring_desc *d = vhost_get_meta_ptr(vq, VHOST_ADDR_DESC);
- rcu_read_unlock();
+ if (likely(d)) {
+ *desc = *(d + idx);
+ vhost_put_meta_ptr();
+ return 0;
}
#endif
--
2.18.1
next prev parent reply other threads:[~2019-07-17 10:53 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-17 10:52 [PATCH V3 00/15] Packed virtqueue support for vhost Jason Wang
2019-07-17 10:52 ` Jason Wang [this message]
2019-07-17 10:52 ` [PATCH V3 02/15] vhost: remove the unnecessary parameter of vhost_vq_avail_empty() Jason Wang
2019-07-17 10:52 ` [PATCH V3 03/15] vhost: remove unnecessary parameter of vhost_enable_notify()/vhost_disable_notify Jason Wang
2019-07-17 10:52 ` [PATCH V3 04/15] vhost-net: don't use vhost_add_used_n() for zerocopy Jason Wang
2019-07-17 10:52 ` [PATCH V3 05/15] vhost: introduce helpers to manipulate shadow used ring Jason Wang
2019-07-17 10:52 ` [PATCH V3 06/15] vhost_net: switch TX to use shadow used ring API Jason Wang
2019-07-17 10:52 ` [PATCH V3 07/15] vhost_net: calculate last used length once for mergeable buffer Jason Wang
2019-07-17 10:52 ` [PATCH V3 08/15] vhost_net: switch to use shadow used ring API for RX Jason Wang
2019-07-17 10:52 ` [PATCH V3 09/15] vhost: do not export vhost_add_used_n() and vhost_add_used_and_signal_n() Jason Wang
2019-07-17 10:52 ` [PATCH V3 10/15] vhost: hide used ring layout from device Jason Wang
2019-07-17 10:52 ` [PATCH V3 11/15] vhost: do not use vring_used_elem Jason Wang
2019-07-17 10:52 ` [PATCH V3 12/15] vhost: vhost_put_user() can accept metadata type Jason Wang
2019-07-17 10:52 ` [PATCH V3 13/15] vhost: packed ring support Jason Wang
2019-07-17 10:52 ` [PATCH V3 14/15] vhost: event suppression for packed ring Jason Wang
2019-07-17 10:52 ` [PATCH V3 15/15] vhost: enable packed virtqueues Jason Wang
2019-07-17 11:02 ` [PATCH V3 00/15] Packed virtqueue support for vhost Michael S. Tsirkin
2019-07-17 12:27 ` Jason Wang
2019-07-17 14:28 ` Michael S. Tsirkin
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