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Message-Id: <20240130114224.86536-7-xuanzhuo@linux.alibaba.com>
Date: Tue, 30 Jan 2024 19:42:13 +0800
From: Xuan Zhuo <xuanzhuo@...ux.alibaba.com>
To: virtualization@...ts.linux.dev
Cc: Richard Weinberger <richard@....at>,
Anton Ivanov <anton.ivanov@...bridgegreys.com>,
Johannes Berg <johannes@...solutions.net>,
"Michael S. Tsirkin" <mst@...hat.com>,
Jason Wang <jasowang@...hat.com>,
Xuan Zhuo <xuanzhuo@...ux.alibaba.com>,
"David S. Miller" <davem@...emloft.net>,
Eric Dumazet <edumazet@...gle.com>,
Jakub Kicinski <kuba@...nel.org>,
Paolo Abeni <pabeni@...hat.com>,
Hans de Goede <hdegoede@...hat.com>,
Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>,
Vadim Pasternak <vadimp@...dia.com>,
Bjorn Andersson <andersson@...nel.org>,
Mathieu Poirier <mathieu.poirier@...aro.org>,
Cornelia Huck <cohuck@...hat.com>,
Halil Pasic <pasic@...ux.ibm.com>,
Eric Farman <farman@...ux.ibm.com>,
Heiko Carstens <hca@...ux.ibm.com>,
Vasily Gorbik <gor@...ux.ibm.com>,
Alexander Gordeev <agordeev@...ux.ibm.com>,
Christian Borntraeger <borntraeger@...ux.ibm.com>,
Sven Schnelle <svens@...ux.ibm.com>,
Alexei Starovoitov <ast@...nel.org>,
Daniel Borkmann <daniel@...earbox.net>,
Jesper Dangaard Brouer <hawk@...nel.org>,
John Fastabend <john.fastabend@...il.com>,
Benjamin Berg <benjamin.berg@...el.com>,
Yang Li <yang.lee@...ux.alibaba.com>,
linux-um@...ts.infradead.org,
netdev@...r.kernel.org,
platform-driver-x86@...r.kernel.org,
linux-remoteproc@...r.kernel.org,
linux-s390@...r.kernel.org,
kvm@...r.kernel.org,
bpf@...r.kernel.org
Subject: [PATCH vhost 06/17] virtio_ring: no store dma info when unmap is not needed
As discussed:
http://lore.kernel.org/all/CACGkMEug-=C+VQhkMYSgUKMC==04m7-uem_yC21bgGkKZh845w@mail.gmail.com
When the vq is premapped mode, the driver manages the dma
info is a good way.
So this commit make the virtio core not to store the dma
info and release the memory which is used to store the dma
info.
If the use_dma_api is false, the memory is also not allocated.
Signed-off-by: Xuan Zhuo <xuanzhuo@...ux.alibaba.com>
---
drivers/virtio/virtio_ring.c | 89 ++++++++++++++++++++++++++++--------
1 file changed, 70 insertions(+), 19 deletions(-)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 831667a57429..5bea25167259 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -94,12 +94,15 @@ struct vring_desc_state_packed {
};
struct vring_desc_extra {
- dma_addr_t addr; /* Descriptor DMA addr. */
- u32 len; /* Descriptor length. */
u16 flags; /* Descriptor flags. */
u16 next; /* The next desc state in a list. */
};
+struct vring_desc_dma {
+ dma_addr_t addr; /* Descriptor DMA addr. */
+ u32 len; /* Descriptor length. */
+};
+
struct vring_virtqueue_split {
/* Actual memory layout for this queue. */
struct vring vring;
@@ -116,6 +119,7 @@ struct vring_virtqueue_split {
/* Per-descriptor state. */
struct vring_desc_state_split *desc_state;
struct vring_desc_extra *desc_extra;
+ struct vring_desc_dma *desc_dma;
/* DMA address and size information */
dma_addr_t queue_dma_addr;
@@ -156,6 +160,7 @@ struct vring_virtqueue_packed {
/* Per-descriptor state. */
struct vring_desc_state_packed *desc_state;
struct vring_desc_extra *desc_extra;
+ struct vring_desc_dma *desc_dma;
/* DMA address and size information */
dma_addr_t ring_dma_addr;
@@ -472,13 +477,14 @@ static unsigned int vring_unmap_one_split(const struct vring_virtqueue *vq,
unsigned int i)
{
struct vring_desc_extra *extra = vq->split.desc_extra;
+ struct vring_desc_dma *dma = vq->split.desc_dma;
u16 flags;
flags = extra[i].flags;
dma_unmap_page(vring_dma_dev(vq),
- extra[i].addr,
- extra[i].len,
+ dma[i].addr,
+ dma[i].len,
(flags & VRING_DESC_F_WRITE) ?
DMA_FROM_DEVICE : DMA_TO_DEVICE);
@@ -535,8 +541,11 @@ static inline unsigned int virtqueue_add_desc_split(struct virtqueue *vq,
next = extra[i].next;
desc[i].next = cpu_to_virtio16(vq->vdev, next);
- extra[i].addr = addr;
- extra[i].len = len;
+ if (vring->split.desc_dma) {
+ vring->split.desc_dma[i].addr = addr;
+ vring->split.desc_dma[i].len = len;
+ }
+
extra[i].flags = flags;
} else
next = virtio16_to_cpu(vq->vdev, desc[i].next);
@@ -1072,16 +1081,26 @@ static void virtqueue_vring_attach_split(struct vring_virtqueue *vq,
vq->free_head = 0;
}
-static int vring_alloc_state_extra_split(struct vring_virtqueue_split *vring_split)
+static int vring_alloc_state_extra_split(struct vring_virtqueue_split *vring_split,
+ bool need_unmap)
{
struct vring_desc_state_split *state;
struct vring_desc_extra *extra;
+ struct vring_desc_dma *dma;
u32 num = vring_split->vring.num;
state = kmalloc_array(num, sizeof(struct vring_desc_state_split), GFP_KERNEL);
if (!state)
goto err_state;
+ if (need_unmap) {
+ dma = kmalloc_array(num, sizeof(struct vring_desc_dma), GFP_KERNEL);
+ if (!dma)
+ goto err_dma;
+ } else {
+ dma = NULL;
+ }
+
extra = vring_alloc_desc_extra(num);
if (!extra)
goto err_extra;
@@ -1090,9 +1109,12 @@ static int vring_alloc_state_extra_split(struct vring_virtqueue_split *vring_spl
vring_split->desc_state = state;
vring_split->desc_extra = extra;
+ vring_split->desc_dma = dma;
return 0;
err_extra:
+ kfree(dma);
+err_dma:
kfree(state);
err_state:
return -ENOMEM;
@@ -1108,6 +1130,7 @@ static void vring_free_split(struct vring_virtqueue_split *vring_split,
kfree(vring_split->desc_state);
kfree(vring_split->desc_extra);
+ kfree(vring_split->desc_dma);
}
static int vring_alloc_queue_split(struct vring_virtqueue_split *vring_split,
@@ -1209,7 +1232,8 @@ static int virtqueue_resize_split(struct virtqueue *_vq, u32 num)
if (err)
goto err;
- err = vring_alloc_state_extra_split(&vring_split);
+ err = vring_alloc_state_extra_split(&vring_split,
+ vring_need_unmap_buffer(vq));
if (err)
goto err_state_extra;
@@ -1245,14 +1269,16 @@ static u16 packed_last_used(u16 last_used_idx)
/* caller must check vring_need_unmap_buffer() */
static void vring_unmap_extra_packed(const struct vring_virtqueue *vq,
- const struct vring_desc_extra *extra)
+ unsigned int i)
{
+ const struct vring_desc_extra *extra = &vq->packed.desc_extra[i];
+ const struct vring_desc_dma *dma = &vq->packed.desc_dma[i];
u16 flags;
flags = extra->flags;
dma_unmap_page(vring_dma_dev(vq),
- extra->addr, extra->len,
+ dma->addr, dma->len,
(flags & VRING_DESC_F_WRITE) ?
DMA_FROM_DEVICE : DMA_TO_DEVICE);
}
@@ -1499,8 +1525,8 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq,
desc[i].id = cpu_to_le16(id);
if (unlikely(vring_need_unmap_buffer(vq))) {
- vq->packed.desc_extra[curr].addr = addr;
- vq->packed.desc_extra[curr].len = sg->length;
+ vq->packed.desc_dma[curr].addr = addr;
+ vq->packed.desc_dma[curr].len = sg->length;
}
vq->packed.desc_extra[curr].flags = le16_to_cpu(flags);
@@ -1559,7 +1585,7 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq,
for (n = 0; n < total_sg; n++) {
if (i == err_idx)
break;
- vring_unmap_extra_packed(vq, &vq->packed.desc_extra[curr]);
+ vring_unmap_extra_packed(vq, curr);
curr = vq->packed.desc_extra[curr].next;
i++;
if (i >= vq->packed.vring.num)
@@ -1640,8 +1666,7 @@ static void detach_buf_packed(struct vring_virtqueue *vq,
if (vring_need_unmap_buffer(vq)) {
curr = id;
for (i = 0; i < state->num; i++) {
- vring_unmap_extra_packed(vq,
- &vq->packed.desc_extra[curr]);
+ vring_unmap_extra_packed(vq, curr);
curr = vq->packed.desc_extra[curr].next;
}
}
@@ -1955,6 +1980,7 @@ static void vring_free_packed(struct vring_virtqueue_packed *vring_packed,
kfree(vring_packed->desc_state);
kfree(vring_packed->desc_extra);
+ kfree(vring_packed->desc_dma);
}
static int vring_alloc_queue_packed(struct vring_virtqueue_packed *vring_packed,
@@ -2011,10 +2037,12 @@ static int vring_alloc_queue_packed(struct vring_virtqueue_packed *vring_packed,
return -ENOMEM;
}
-static int vring_alloc_state_extra_packed(struct vring_virtqueue_packed *vring_packed)
+static int vring_alloc_state_extra_packed(struct vring_virtqueue_packed *vring_packed,
+ bool need_unmap)
{
struct vring_desc_state_packed *state;
struct vring_desc_extra *extra;
+ struct vring_desc_dma *dma;
u32 num = vring_packed->vring.num;
state = kmalloc_array(num, sizeof(struct vring_desc_state_packed), GFP_KERNEL);
@@ -2023,6 +2051,14 @@ static int vring_alloc_state_extra_packed(struct vring_virtqueue_packed *vring_p
memset(state, 0, num * sizeof(struct vring_desc_state_packed));
+ if (need_unmap) {
+ dma = kmalloc_array(num, sizeof(struct vring_desc_dma), GFP_KERNEL);
+ if (!dma)
+ goto err_desc_dma;
+ } else {
+ dma = NULL;
+ }
+
extra = vring_alloc_desc_extra(num);
if (!extra)
goto err_desc_extra;
@@ -2033,6 +2069,8 @@ static int vring_alloc_state_extra_packed(struct vring_virtqueue_packed *vring_p
return 0;
err_desc_extra:
+ kfree(dma);
+err_desc_dma:
kfree(state);
err_desc_state:
return -ENOMEM;
@@ -2124,7 +2162,8 @@ static struct virtqueue *vring_create_virtqueue_packed(
if (virtio_has_feature(vdev, VIRTIO_F_ORDER_PLATFORM))
vq->weak_barriers = false;
- err = vring_alloc_state_extra_packed(&vring_packed);
+ err = vring_alloc_state_extra_packed(&vring_packed,
+ vring_need_unmap_buffer(vq));
if (err)
goto err_state_extra;
@@ -2156,7 +2195,8 @@ static int virtqueue_resize_packed(struct virtqueue *_vq, u32 num)
if (vring_alloc_queue_packed(&vring_packed, vdev, num, vring_dma_dev(vq)))
goto err_ring;
- err = vring_alloc_state_extra_packed(&vring_packed);
+ err = vring_alloc_state_extra_packed(&vring_packed,
+ vring_need_unmap_buffer(vq));
if (err)
goto err_state_extra;
@@ -2668,7 +2708,8 @@ static struct virtqueue *__vring_new_virtqueue(unsigned int index,
if (virtio_has_feature(vdev, VIRTIO_F_ORDER_PLATFORM))
vq->weak_barriers = false;
- err = vring_alloc_state_extra_split(vring_split);
+ err = vring_alloc_state_extra_split(vring_split,
+ vring_need_unmap_buffer(vq));
if (err) {
kfree(vq);
return NULL;
@@ -2828,6 +2869,14 @@ int virtqueue_set_dma_premapped(struct virtqueue *_vq)
vq->premapped = true;
+ if (vq->packed_ring) {
+ kfree(vq->packed.desc_dma);
+ vq->packed.desc_dma = NULL;
+ } else {
+ kfree(vq->split.desc_dma);
+ vq->split.desc_dma = NULL;
+ }
+
END_USE(vq);
return 0;
@@ -2917,6 +2966,7 @@ static void vring_free(struct virtqueue *_vq)
kfree(vq->packed.desc_state);
kfree(vq->packed.desc_extra);
+ kfree(vq->packed.desc_dma);
} else {
vring_free_queue(vq->vq.vdev,
vq->split.queue_size_in_bytes,
@@ -2928,6 +2978,7 @@ static void vring_free(struct virtqueue *_vq)
if (!vq->packed_ring) {
kfree(vq->split.desc_state);
kfree(vq->split.desc_extra);
+ kfree(vq->split.desc_dma);
}
}
--
2.32.0.3.g01195cf9f
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