On Fri, May 16, 2025 at 09:30:01AM +0800, Jason Wang wrote:
> On Wed, May 14, 2025 at 10:24 PM Michael S. Tsirkin <mst@xxxxxxxxxx> wrote:
> >
> > On Wed, May 14, 2025 at 10:19:05AM -0400, Michael S. Tsirkin wrote:
> > > On Wed, Apr 09, 2025 at 12:06:03PM +0800, Jason Wang wrote:
> > > > On Tue, Apr 8, 2025 at 7:37 PM Michael S. Tsirkin <mst@xxxxxxxxxx> wrote:
> > > > >
> > > > > On Tue, Apr 08, 2025 at 03:02:35PM +0800, Jason Wang wrote:
> > > > > > On Mon, Apr 7, 2025 at 4:20 PM Michael S. Tsirkin <mst@xxxxxxxxxx> wrote:
> > > > > > >
> > > > > > > On Mon, Mar 24, 2025 at 02:01:21PM +0800, Jason Wang wrote:
> > > > > > > > This patch introduces virtqueue ops which is a set of the callbacks
> > > > > > > > that will be called for different queue layout or features. This would
> > > > > > > > help to avoid branches for split/packed and will ease the future
> > > > > > > > implementation like in order.
> > > > > > > >
> > > > > > > > Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > > > > ---
> > > > > > > > drivers/virtio/virtio_ring.c | 96 +++++++++++++++++++++++++-----------
> > > > > > > > 1 file changed, 67 insertions(+), 29 deletions(-)
> > > > > > > >
> > > > > > > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> > > > > > > > index a2884eae14d9..ce1dc90ee89d 100644
> > > > > > > > --- a/drivers/virtio/virtio_ring.c
> > > > > > > > +++ b/drivers/virtio/virtio_ring.c
> > > > > > > > @@ -159,9 +159,30 @@ struct vring_virtqueue_packed {
> > > > > > > > size_t event_size_in_bytes;
> > > > > > > > };
> > > > > > > >
> > > > > > > > +struct vring_virtqueue;
> > > > > > > > +
> > > > > > > > +struct virtqueue_ops {
> > > > > > > > + int (*add)(struct vring_virtqueue *_vq, struct scatterlist *sgs[],
> > > > > > > > + unsigned int total_sg, unsigned int out_sgs,
> > > > > > > > + unsigned int in_sgs, void *data,
> > > > > > > > + void *ctx, bool premapped, gfp_t gfp);
> > > > > > > > + void *(*get)(struct vring_virtqueue *vq, unsigned int *len, void **ctx);
> > > > > > > > + bool (*kick_prepare)(struct vring_virtqueue *vq);
> > > > > > > > + void (*disable_cb)(struct vring_virtqueue *vq);
> > > > > > > > + bool (*enable_cb_delayed)(struct vring_virtqueue *vq);
> > > > > > > > + unsigned int (*enable_cb_prepare)(struct vring_virtqueue *vq);
> > > > > > > > + bool (*poll)(const struct vring_virtqueue *vq, u16 last_used_idx);
> > > > > > > > + void *(*detach_unused_buf)(struct vring_virtqueue *vq);
> > > > > > > > + bool (*more_used)(const struct vring_virtqueue *vq);
> > > > > > > > + int (*resize)(struct vring_virtqueue *vq, u32 num);
> > > > > > > > + void (*reset)(struct vring_virtqueue *vq);
> > > > > > > > +};
> > > > > > >
> > > > > > > I like it that it's organized but
> > > > > > > I worry about the overhead of indirect calls here.
> > > > > >
> > > > > > We can switch to use INDIRECT_CALL_X() here
> > > > >
> > > > > If you think it's cleaner.. but INDIRECT_CALL is all chained
> > > >
> > > > Yes, and it would be problematic as the number of ops increased.
> > > >
> > > > > while a switch can do a binary search.
> > > > >
> > > >
> > > > Do you mean a nested switch?
> > >
> > > Not sure what is nested. gcc does a decent job of optimizing
> > > switches. You have 4 types of ops:
> > > packed/packed in order/split/split in order
> > >
> > > So:
> > >
> > > enum {
> > > VQ_SPLIT,
> > > VQ_SPLIT_IN_ORDER,
> > > VQ_PACKED,
> > > VQ_PACKED_IN_ORDER,
> > > }
> > >
> > >
> > > I do not see how it is worse?
> > >
> > >
> >
> >
> >
> > Actually, here is an idea - create an array of ops:
> >
> >
> >
> > enum vqtype {
> > SPLIT,
> > SPLIT_IN_ORDER,
> > PACKED,
> > PACKED_IN_ORDER,
> > MAX
> > };
> >
> >
> > struct ops {
> > int (*add)(int bar);
> > };
> >
> > extern int packed(int);
> > extern int packedinorder(int);
> > extern int split(int);
> > extern int splitinorder(int);
> >
> > const struct ops allops[MAX] = { [SPLIT] = {split}, [SPLIT_IN_ORDER] = { splitinorder}, [PACKED] = { packed }, [PACKED_IN_ORDER] = {packedinorder}};
> >
> > int main(int argc, char **argv)
> > {
> > switch (argc) {
> > case 0:
> > return allops[PACKED].foo(argc);
> > case 1:
> > return allops[SPLIT].foo(argc);
> > default:
> > return allops[PACKED_IN_ORDER].foo(argc);
>
> This still looks like an indirection call as we don't call the symbol
> directly but need to load the function address into a register.
See below.
> > }
> > }
> >
> >
> > I tested this and compiler is able to elide the indirect calls.
>
> I've tried the following:
>
> struct virtqueue_ops split_ops = {
> .add = virtqueue_add_split,
> .get = virtqueue_get_buf_ctx_split,
> .kick_prepare = virtqueue_kick_prepare_split,
> .disable_cb = virtqueue_disable_cb_split,
> .enable_cb_delayed = virtqueue_enable_cb_delayed_split,
> .enable_cb_prepare = virtqueue_enable_cb_prepare_split,
> .poll = virtqueue_poll_split,
> .detach_unused_buf = virtqueue_detach_unused_buf_split,
> .more_used = more_used_split,
> .resize = virtqueue_resize_split,
> .reset = virtqueue_reset_split,
> };
>
> struct virtqueue_ops packed_ops = {
> .add = virtqueue_add_packed,
> .get = virtqueue_get_buf_ctx_packed,
> .kick_prepare = virtqueue_kick_prepare_packed,
> .disable_cb = virtqueue_disable_cb_packed,
> .enable_cb_delayed = virtqueue_enable_cb_delayed_packed,
> .enable_cb_prepare = virtqueue_enable_cb_prepare_packed,
> .poll = virtqueue_poll_packed,
> .detach_unused_buf = virtqueue_detach_unused_buf_packed,
> .more_used = more_used_packed,
> .resize = virtqueue_resize_packed,
> .reset = virtqueue_reset_packed,
> };
>
> const struct virtqueue_ops *all_ops[VQ_TYPE_MAX] = { [SPLIT] = &split_ops,
> [PACKED] = &packed_ops};
>
> unsigned int virtqueue_enable_cb_prepare(struct virtqueue *_vq)
> {
> struct vring_virtqueue *vq = to_vvq(_vq);
>
> if (vq->event_triggered)
> vq->event_triggered = false;
>
> switch (vq->layout) {
> case SPLIT:
> return all_ops[SPLIT]->enable_cb_prepare(vq);
> break;
> case PACKED:
> return all_ops[PACKED]->enable_cb_prepare(vq);
> break;
> default:
> BUG();
> break;
> }
>
> return -EFAULT;
> }
> EXPORT_SYMBOL_GPL(virtqueue_enable_cb_prepare);
>
> Compilers gives me (when RETPOLINE is enabled):
>
> ffffffff8193a870 <virtqueue_enable_cb_prepare>:
> ffffffff8193a870: f3 0f 1e fa endbr64
> ffffffff8193a874: e8 47 68 93 ff callq
> ffffffff812710c0 <__fentry__>
> ffffffff8193a879: 80 bf 8e 00 00 00 00 cmpb $0x0,0x8e(%rdi)
> ffffffff8193a880: 74 07 je
> ffffffff8193a889 <virtqueue_enable_cb_prepare+0x19>
> ffffffff8193a882: c6 87 8e 00 00 00 00 movb $0x0,0x8e(%rdi)
> ffffffff8193a889: 8b 87 80 00 00 00 mov 0x80(%rdi),%eax
> ffffffff8193a88f: 85 c0 test %eax,%eax
> ffffffff8193a891: 74 15 je
> ffffffff8193a8a8 <virtqueue_enable_cb_prepare+0x38>
> ffffffff8193a893: 83 f8 01 cmp $0x1,%eax
> ffffffff8193a896: 75 20 jne
> ffffffff8193a8b8 <virtqueue_enable_cb_prepare+0x48>
> ffffffff8193a898: 48 8b 05 49 03 4a 01 mov
> 0x14a0349(%rip),%rax # ffffffff82ddabe8 <all_ops+0x8>
> ffffffff8193a89f: 48 8b 40 28 mov 0x28(%rax),%rax
> ffffffff8193a8a3: e9 b8 d8 9b 00 jmpq
> ffffffff822f8160 <__x86_indirect_thunk_array>
> ffffffff8193a8a8: 48 8b 05 31 03 4a 01 mov
> 0x14a0331(%rip),%rax # ffffffff82ddabe0 <all_ops>
> ffffffff8193a8af: 48 8b 40 28 mov 0x28(%rax),%rax
> ffffffff8193a8b3: e9 a8 d8 9b 00 jmpq
> ffffffff822f8160 <__x86_indirect_thunk_array>
> ffffffff8193a8b8: 0f 0b ud2
> ffffffff8193a8ba: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1)
>
> indirection call is still being mitigated via thunk.
This is because you put the pointers there, and the pointers
are not const themselves.
const struct virtqueue_ops * const all_ops[VQ_TYPE_MAX]
should do the trick.
Here is the example I wrote:
enum vqtype {
SPLIT,
SPLIT_IN_ORDER,
PACKED,
PACKED_IN_ORDER,
MAX
};
struct ops {
int (*foo)(int bar);
};
extern int packed(int);
extern int packedinorder(int);
extern int split(int);
extern int splitinorder(int);
const struct ops splitops = { split };
const struct ops packedops = { packed };
const struct ops packedinorderops = { packedinorder };
const struct ops splitinorderops = { splitinorder };
const struct ops *const allopsp[MAX] = { [SPLIT] = &splitops, [SPLIT_IN_ORDER] = &splitinorderops, [PACKED] = &packedops, [PACKED_IN_ORDER] = &packedinorderops};
const struct ops allops[MAX] = { [SPLIT] = {split}, [SPLIT_IN_ORDER] = { splitinorder}, [PACKED] = { packed }, [PACKED_IN_ORDER] = {packedinorder}};
int foo(int argc)
{
switch (argc) {
case 0:
return allops[PACKED].foo(argc);
case 1:
return allops[SPLIT].foo(argc);
case 2:
return allops[PACKED_IN_ORDER].foo(argc);
case 3:
return allops[SPLIT_IN_ORDER].foo(argc);
default:
return 0;
}
}
extern int foo(int argc);
int bar(int argc)
{
switch (argc) {
case 0:
return allopsp[PACKED]->foo(argc);
case 1:
return allopsp[SPLIT]->foo(argc);
case 2:
return allopsp[PACKED_IN_ORDER]->foo(argc);
case 3:
return allopsp[SPLIT_IN_ORDER]->foo(argc);
default:
return 0;
}
}
extern int bar(int argc);
int main(int argc, char **argv)
{
foo(argc);
bar(argc);
return 0;
}
then:
$ gcc -c -O2 -ggdb main.c
$ objdump -r -ld main.o
main.o: file format elf64-x86-64
mst@tuck:~$ objdump -r -ld main.o
main.o: file format elf64-x86-64
Disassembly of section .text:
0000000000000000 <foo>:
foo():
/home/mst/main.c:29
0: 83 ff 02 cmp $0x2,%edi
3: 74 2a je 2f <foo+0x2f>
5: 7f 12 jg 19 <foo+0x19>
7: 85 ff test %edi,%edi
9: 74 1d je 28 <foo+0x28>
b: ff cf dec %edi
d: 75 2a jne 39 <foo+0x39>
/home/mst/main.c:33
f: bf 01 00 00 00 mov $0x1,%edi
14: e9 00 00 00 00 jmp 19 <foo+0x19>
15: R_X86_64_PLT32 split-0x4
/home/mst/main.c:29
19: 83 ff 03 cmp $0x3,%edi
1c: 75 1b jne 39 <foo+0x39>
/home/mst/main.c:37
1e: bf 03 00 00 00 mov $0x3,%edi
23: e9 00 00 00 00 jmp 28 <foo+0x28>
24: R_X86_64_PLT32 splitinorder-0x4
/home/mst/main.c:31
28: 31 ff xor %edi,%edi
2a: e9 00 00 00 00 jmp 2f <foo+0x2f>
2b: R_X86_64_PLT32 packed-0x4
/home/mst/main.c:35
2f: bf 02 00 00 00 mov $0x2,%edi
34: e9 00 00 00 00 jmp 39 <foo+0x39>
35: R_X86_64_PLT32 packedinorder-0x4
/home/mst/main.c:41
39: 31 c0 xor %eax,%eax
3b: c3 ret
000000000000003c <bar>:
bar():
/home/mst/main.c:43
3c: eb c2 jmp 0 <foo>
Disassembly of section .text.startup:
0000000000000000 <main>:
main():
/home/mst/main.c:60
0: 48 83 ec 18 sub $0x18,%rsp
/home/mst/main.c:61
4: 89 7c 24 0c mov %edi,0xc(%rsp)
8: e8 00 00 00 00 call d <main+0xd>
9: R_X86_64_PLT32 foo-0x4
/home/mst/main.c:62
d: 8b 7c 24 0c mov 0xc(%rsp),%edi
11: e8 00 00 00 00 call 16 <main+0x16>
12: R_X86_64_PLT32 foo-0x4
/home/mst/main.c:64
16: 31 c0 xor %eax,%eax
18: 48 83 c4 18 add $0x18,%rsp
compiler was able to figure out they are the same.
> The way I can think so far is something like this that passess the
> function symbol to the macro:
>
> #define VIRTQUEUE_CALL(vq, split_fn, packed_fn, ...) \
> ({ \
> typeof(split_fn(vq, ##__VA_ARGS__)) ret; \
> switch ((vq)->layout) { \
> case SPLIT: \
> ret = split_fn(vq, ##__VA_ARGS__); \
> break; \
> case PACKED: \
> ret = packed_fn(vq, ##__VA_ARGS__); \
> break; \
> default: \
> BUG(); \
> ret = (typeof(ret))-EFAULT; \
> break; \
> } \
> ret; \
> })
>
> Then I can't see RETPOLINE for indirect calls.
>
> Thanks
So check out my hack I think a bit cleaner?
Or really we can do e.g. two INDIRECT calls chained,
I will think if we can combine it with the array hack
maybe.
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > >
> > >
> > >
> > >
> > >
> > >
> > > > >
> > > > > > (but I'm not sure we
> > > > > > should worry about it too much as ndo_ops or qdiscs doesn't use that).
> > > > >
> > > > >
> > > > > And that's why we ended up with xdp, no? the stack's too heavy ...
> > > > >
> > > > > > > How about a switch statement instead?
> > > > > > >
> > > > > > > struct vring_virtqueue {
> > > > > > > enum vring_virtqueue_ops ops;
> > > > > > >
> > > > > > > }
> > > > > > >
> > > > > > >
> > > > > > > @@ -2248,10 +2303,8 @@ static inline int virtqueue_add(struct virtqueue *_vq,
> > > > > > > {
> > > > > > > struct vring_virtqueue *vq = to_vvq(_vq);
> > > > > > >
> > > > > > > switch (vq->ops) {
> > > > > > > VQ_PACKED:
> > > > > > > VQ_SPLIT:
> > > > > > > VQ_IN_ORDER:
> > > > > > > }
> > > > > > >
> > > > > > >
> > > > > > > }
> > > > > > >
> > > > > > >
> > > > > > > What do you think?
> > > > > >
> > > > > > Actually, the matrix will be 2*2:
> > > > > >
> > > > > > PACKED, SPLIT, PACKED_IN_ORDER, SPLIT_IN_ORDER
> > > > >
> > > > > Confused. Same amount of enums as ops structures in your approach, no?
> > > >
> > > > I meant in this series, we will have 4 ops not 3.
> > > >
> > > > >
> > > > >
> > > > > > And will be doubled if a new layout is implemented.
> > > > > >
> > > > > > If we open them such a switch will spread in a lot of places in the code.
> > > > > >
> > > > > > Thanks
> > > >
> > > > Thanks
> > > >
> > > > > >
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > > > > +
> > > > > > > > struct vring_virtqueue {
> > > > > > > > struct virtqueue vq;
> > > > > > > >
> > > > > > > > + struct virtqueue_ops *ops;
> > > > > > > > +
> > > > > > > > /* Is this a packed ring? */
> > > > > > > > bool packed_ring;
> > > > > > > >
> > > > > > > > @@ -1116,6 +1137,8 @@ static int vring_alloc_queue_split(struct vring_virtqueue_split *vring_split,
> > > > > > > > return 0;
> > > > > > > > }
> > > > > > > >
> > > > > > > > +struct virtqueue_ops split_ops;
> > > > > > > > +
> > > > > > > > static struct virtqueue *__vring_new_virtqueue_split(unsigned int index,
> > > > > > > > struct vring_virtqueue_split *vring_split,
> > > > > > > > struct virtio_device *vdev,
> > > > > > > > @@ -1134,6 +1157,7 @@ static struct virtqueue *__vring_new_virtqueue_split(unsigned int index,
> > > > > > > > return NULL;
> > > > > > > >
> > > > > > > > vq->packed_ring = false;
> > > > > > > > + vq->ops = &split_ops;
> > > > > > > > vq->vq.callback = callback;
> > > > > > > > vq->vq.vdev = vdev;
> > > > > > > > vq->vq.name = name;
> > > > > > > > @@ -2076,6 +2100,8 @@ static void virtqueue_reset_packed(struct vring_virtqueue *vq)
> > > > > > > > virtqueue_vring_init_packed(&vq->packed, !!vq->vq.callback);
> > > > > > > > }
> > > > > > > >
> > > > > > > > +struct virtqueue_ops packed_ops;
> > > > > > > > +
> > > > > > > > static struct virtqueue *__vring_new_virtqueue_packed(unsigned int index,
> > > > > > > > struct vring_virtqueue_packed *vring_packed,
> > > > > > > > struct virtio_device *vdev,
> > > > > > > > @@ -2107,6 +2133,7 @@ static struct virtqueue *__vring_new_virtqueue_packed(unsigned int index,
> > > > > > > > vq->broken = false;
> > > > > > > > #endif
> > > > > > > > vq->packed_ring = true;
> > > > > > > > + vq->ops = &packed_ops;
> > > > > > > > vq->dma_dev = dma_dev;
> > > > > > > > vq->use_dma_api = vring_use_dma_api(vdev);
> > > > > > > >
> > > > > > > > @@ -2194,6 +2221,34 @@ static int virtqueue_resize_packed(struct vring_virtqueue *vq, u32 num)
> > > > > > > > return -ENOMEM;
> > > > > > > > }
> > > > > > > >
> > > > > > > > +struct virtqueue_ops split_ops = {
> > > > > > > > + .add = virtqueue_add_split,
> > > > > > > > + .get = virtqueue_get_buf_ctx_split,
> > > > > > > > + .kick_prepare = virtqueue_kick_prepare_split,
> > > > > > > > + .disable_cb = virtqueue_disable_cb_split,
> > > > > > > > + .enable_cb_delayed = virtqueue_enable_cb_delayed_split,
> > > > > > > > + .enable_cb_prepare = virtqueue_enable_cb_prepare_split,
> > > > > > > > + .poll = virtqueue_poll_split,
> > > > > > > > + .detach_unused_buf = virtqueue_detach_unused_buf_split,
> > > > > > > > + .more_used = more_used_split,
> > > > > > > > + .resize = virtqueue_resize_split,
> > > > > > > > + .reset = virtqueue_reset_split,
> > > > > > > > +};
> > > > > > > > +
> > > > > > > > +struct virtqueue_ops packed_ops = {
> > > > > > > > + .add = virtqueue_add_packed,
> > > > > > > > + .get = virtqueue_get_buf_ctx_packed,
> > > > > > > > + .kick_prepare = virtqueue_kick_prepare_packed,
> > > > > > > > + .disable_cb = virtqueue_disable_cb_packed,
> > > > > > > > + .enable_cb_delayed = virtqueue_enable_cb_delayed_packed,
> > > > > > > > + .enable_cb_prepare = virtqueue_enable_cb_prepare_packed,
> > > > > > > > + .poll = virtqueue_poll_packed,
> > > > > > > > + .detach_unused_buf = virtqueue_detach_unused_buf_packed,
> > > > > > > > + .more_used = more_used_packed,
> > > > > > > > + .resize = virtqueue_resize_packed,
> > > > > > > > + .reset = virtqueue_reset_packed,
> > > > > > > > +};
> > > > > > > > +
> > > > > > > > static int virtqueue_disable_and_recycle(struct virtqueue *_vq,
> > > > > > > > void (*recycle)(struct virtqueue *vq, void *buf))
> > > > > > > > {
> > > > > > > > @@ -2248,10 +2303,8 @@ static inline int virtqueue_add(struct virtqueue *_vq,
> > > > > > > > {
> > > > > > > > struct vring_virtqueue *vq = to_vvq(_vq);
> > > > > > > >
> > > > > > > > - return vq->packed_ring ? virtqueue_add_packed(vq, sgs, total_sg,
> > > > > > > > - out_sgs, in_sgs, data, ctx, premapped, gfp) :
> > > > > > > > - virtqueue_add_split(vq, sgs, total_sg,
> > > > > > > > - out_sgs, in_sgs, data, ctx, premapped, gfp);
> > > > > > > > + return vq->ops->add(vq, sgs, total_sg,
> > > > > > > > + out_sgs, in_sgs, data, ctx, premapped, gfp);
> > > > > > > > }
> > > > > > > >
> > > > > > > > /**
> > > > > > > > @@ -2437,8 +2490,7 @@ bool virtqueue_kick_prepare(struct virtqueue *_vq)
> > > > > > > > {
> > > > > > > > struct vring_virtqueue *vq = to_vvq(_vq);
> > > > > > > >
> > > > > > > > - return vq->packed_ring ? virtqueue_kick_prepare_packed(vq) :
> > > > > > > > - virtqueue_kick_prepare_split(vq);
> > > > > > > > + return vq->ops->kick_prepare(vq);
> > > > > > > > }
> > > > > > > > EXPORT_SYMBOL_GPL(virtqueue_kick_prepare);
> > > > > > > >
> > > > > > > > @@ -2508,8 +2560,7 @@ void *virtqueue_get_buf_ctx(struct virtqueue *_vq, unsigned int *len,
> > > > > > > > {
> > > > > > > > struct vring_virtqueue *vq = to_vvq(_vq);
> > > > > > > >
> > > > > > > > - return vq->packed_ring ? virtqueue_get_buf_ctx_packed(vq, len, ctx) :
> > > > > > > > - virtqueue_get_buf_ctx_split(vq, len, ctx);
> > > > > > > > + return vq->ops->get(vq, len, ctx);
> > > > > > > > }
> > > > > > > > EXPORT_SYMBOL_GPL(virtqueue_get_buf_ctx);
> > > > > > > >
> > > > > > > > @@ -2531,10 +2582,7 @@ void virtqueue_disable_cb(struct virtqueue *_vq)
> > > > > > > > {
> > > > > > > > struct vring_virtqueue *vq = to_vvq(_vq);
> > > > > > > >
> > > > > > > > - if (vq->packed_ring)
> > > > > > > > - virtqueue_disable_cb_packed(vq);
> > > > > > > > - else
> > > > > > > > - virtqueue_disable_cb_split(vq);
> > > > > > > > + return vq->ops->disable_cb(vq);
> > > > > > > > }
> > > > > > > > EXPORT_SYMBOL_GPL(virtqueue_disable_cb);
> > > > > > > >
> > > > > > > > @@ -2557,8 +2605,7 @@ unsigned int virtqueue_enable_cb_prepare(struct virtqueue *_vq)
> > > > > > > > if (vq->event_triggered)
> > > > > > > > vq->event_triggered = false;
> > > > > > > >
> > > > > > > > - return vq->packed_ring ? virtqueue_enable_cb_prepare_packed(vq) :
> > > > > > > > - virtqueue_enable_cb_prepare_split(vq);
> > > > > > > > + return vq->ops->enable_cb_prepare(vq);
> > > > > > > > }
> > > > > > > > EXPORT_SYMBOL_GPL(virtqueue_enable_cb_prepare);
> > > > > > > >
> > > > > > > > @@ -2579,8 +2626,7 @@ bool virtqueue_poll(struct virtqueue *_vq, unsigned int last_used_idx)
> > > > > > > > return false;
> > > > > > > >
> > > > > > > > virtio_mb(vq->weak_barriers);
> > > > > > > > - return vq->packed_ring ? virtqueue_poll_packed(vq, last_used_idx) :
> > > > > > > > - virtqueue_poll_split(vq, last_used_idx);
> > > > > > > > + return vq->ops->poll(vq, last_used_idx);
> > > > > > > > }
> > > > > > > > EXPORT_SYMBOL_GPL(virtqueue_poll);
> > > > > > > >
> > > > > > > > @@ -2623,8 +2669,7 @@ bool virtqueue_enable_cb_delayed(struct virtqueue *_vq)
> > > > > > > > if (vq->event_triggered)
> > > > > > > > vq->event_triggered = false;
> > > > > > > >
> > > > > > > > - return vq->packed_ring ? virtqueue_enable_cb_delayed_packed(vq) :
> > > > > > > > - virtqueue_enable_cb_delayed_split(vq);
> > > > > > > > + return vq->ops->enable_cb_delayed(vq);
> > > > > > > > }
> > > > > > > > EXPORT_SYMBOL_GPL(virtqueue_enable_cb_delayed);
> > > > > > > >
> > > > > > > > @@ -2640,14 +2685,13 @@ void *virtqueue_detach_unused_buf(struct virtqueue *_vq)
> > > > > > > > {
> > > > > > > > struct vring_virtqueue *vq = to_vvq(_vq);
> > > > > > > >
> > > > > > > > - return vq->packed_ring ? virtqueue_detach_unused_buf_packed(vq) :
> > > > > > > > - virtqueue_detach_unused_buf_split(vq);
> > > > > > > > + return vq->ops->detach_unused_buf(vq);
> > > > > > > > }
> > > > > > > > EXPORT_SYMBOL_GPL(virtqueue_detach_unused_buf);
> > > > > > > >
> > > > > > > > static inline bool more_used(const struct vring_virtqueue *vq)
> > > > > > > > {
> > > > > > > > - return vq->packed_ring ? more_used_packed(vq) : more_used_split(vq);
> > > > > > > > + return vq->ops->more_used(vq);
> > > > > > > > }
> > > > > > > >
> > > > > > > > /**
> > > > > > > > @@ -2785,10 +2829,7 @@ int virtqueue_resize(struct virtqueue *_vq, u32 num,
> > > > > > > > if (recycle_done)
> > > > > > > > recycle_done(_vq);
> > > > > > > >
> > > > > > > > - if (vq->packed_ring)
> > > > > > > > - err = virtqueue_resize_packed(vq, num);
> > > > > > > > - else
> > > > > > > > - err = virtqueue_resize_split(vq, num);
> > > > > > > > + err = vq->ops->resize(vq, num);
> > > > > > > >
> > > > > > > > return virtqueue_enable_after_reset(_vq);
> > > > > > > > }
> > > > > > > > @@ -2822,10 +2863,7 @@ int virtqueue_reset(struct virtqueue *_vq,
> > > > > > > > if (recycle_done)
> > > > > > > > recycle_done(_vq);
> > > > > > > >
> > > > > > > > - if (vq->packed_ring)
> > > > > > > > - virtqueue_reset_packed(vq);
> > > > > > > > - else
> > > > > > > > - virtqueue_reset_split(vq);
> > > > > > > > + vq->ops->reset(vq);
> > > > > > > >
> > > > > > > > return virtqueue_enable_after_reset(_vq);
> > > > > > > > }
> > > > > > > > --
> > > > > > > > 2.42.0
> > > > > > >
> > > > >
> >
