search for: vring_sg_address

...ers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 41144b5246a8..fe704ca6c813 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -379,6 +379,14 @@ static dma_addr_t vring_map_one_sg(const struct vring_virtqueue *vq, direction); } +static dma_addr_t vring_sg_address(struct scatterlist *sg) +{ + if (sg->dma_address) + return sg->dma_address; + + return (dma_addr_t)sg_phys(sg); +} + static dma_addr_t vring_map_single(const struct vring_virtqueue *vq, void *cpu_addr, size_t size, enum dma_data_direction direction) @@ -520,6 +528,80 @@ stat...

...ers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index c5310eaf8b46..b073a70c1291 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -379,6 +379,14 @@ static dma_addr_t vring_map_one_sg(const struct vring_virtqueue *vq, direction); } +static dma_addr_t vring_sg_address(struct scatterlist *sg) +{ + if (sg->dma_address) + return sg->dma_address; + + return (dma_addr_t)sg_phys(sg); +} + static dma_addr_t vring_map_single(const struct vring_virtqueue *vq, void *cpu_addr, size_t size, enum dma_data_direction direction) @@ -520,6 +528,80 @@ stat...

...(++c == total_sg ? 0 : VRING_DESC_F_NEXT) | (n < out_sgs ? 0 : VRING_DESC_F_WRITE)); @@ -1496,12 +1493,12 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq, else desc[i].flags = flags; - desc[i].addr = cpu_to_le64(addr); + desc[i].addr = cpu_to_le64(vring_sg_address(sg)); desc[i].len = cpu_to_le32(sg->length); desc[i].id = cpu_to_le16(id); if (unlikely(vq->use_dma_api)) { - vq->packed.desc_extra[curr].addr = addr; + vq->packed.desc_extra[curr].addr = vring_sg_address(sg); vq->packed.desc_extra[curr].len = sg->length;...

...ers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 41144b5246a8..fe704ca6c813 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -379,6 +379,14 @@ static dma_addr_t vring_map_one_sg(const struct vring_virtqueue *vq, direction); } +static dma_addr_t vring_sg_address(struct scatterlist *sg) +{ + if (sg->dma_address) + return sg->dma_address; + + return (dma_addr_t)sg_phys(sg); +} + static dma_addr_t vring_map_single(const struct vring_virtqueue *vq, void *cpu_addr, size_t size, enum dma_data_direction direction) @@ -520,6 +528,80 @@ stat...

> +static dma_addr_t vring_sg_address(struct scatterlist *sg) > +{ > + if (sg->dma_address) > + return sg->dma_address; 0 is a perfectly valid DMA address. So I have no idea how this is even supposed to work.

...100% | 33% | 43% | 771670 Before achieving the function of Virtio-Net, we also have to let virtio core support these features: 1. virtio core support premapped 2. virtio core support reset per-queue 3. introduce DMA APIs to virtio core Please review. Thanks. v8: 1. vring_sg_address: check by sg_page(sg) not dma_address. Because 0 is a valid dma address 2. remove unused code from vring_map_one_sg() v7: 1. virtqueue_dma_dev() return NULL when virtio is without DMA API. v6: 1. change the size of the flags to u32. v5: 1. fix for error handler 2. add flags to record intern...

XDP socket(AF_XDP) is an excellent bypass kernel network framework. The zero copy feature of xsk (XDP socket) needs to be supported by the driver. The performance of zero copy is very good. ENV: Qemu with vhost. vhost cpu | Guest APP CPU |Guest Softirq CPU | PPS -----------------------------|---------------|------------------|------------ xmit by sockperf: 90% | 100%

XDP socket(AF_XDP) is an excellent bypass kernel network framework. The zero copy feature of xsk (XDP socket) needs to be supported by the driver. The performance of zero copy is very good. ENV: Qemu with vhost. vhost cpu | Guest APP CPU |Guest Softirq CPU | PPS -----------------------------|---------------|------------------|------------ xmit by sockperf: 90% | 100%

XDP socket(AF_XDP) is an excellent bypass kernel network framework. The zero copy feature of xsk (XDP socket) needs to be supported by the driver. The performance of zero copy is very good. ENV: Qemu with vhost. vhost cpu | Guest APP CPU |Guest Softirq CPU | PPS -----------------------------|---------------|------------------|------------ xmit by sockperf: 90% | 100%

XDP socket(AF_XDP) is an excellent bypass kernel network framework. The zero copy feature of xsk (XDP socket) needs to be supported by the driver. The performance of zero copy is very good. ENV: Qemu with vhost. vhost cpu | Guest APP CPU |Guest Softirq CPU | PPS -----------------------------|---------------|------------------|------------ xmit by sockperf: 90% | 100%

## About DMA APIs Now, virtio may can not work with DMA APIs when virtio features do not have VIRTIO_F_ACCESS_PLATFORM. 1. I tried to let DMA APIs return phy address by virtio-device. But DMA APIs just work with the "real" devices. 2. I tried to let xsk support callballs to get phy address from virtio-net driver as the dma address. But the maintainers of xsk may want to use

...3. introduce DMA APIs to virtio core Please review. Thanks. v10: 1. support to set vq to premapped mode, then the vq just handles the premapped request. 2. virtio-net support to do dma mapping in advance v9: 1. use flag to distinguish the premapped operations. no do judgment by sg. v8: 1. vring_sg_address: check by sg_page(sg) not dma_address. Because 0 is a valid dma address 2. remove unused code from vring_map_one_sg() v7: 1. virtqueue_dma_dev() return NULL when virtio is without DMA API. v6: 1. change the size of the flags to u32. v5: 1. fix for error handler 2. add flags to record intern...

...3. introduce DMA APIs to virtio core Please review. Thanks. v10: 1. support to set vq to premapped mode, then the vq just handles the premapped request. 2. virtio-net support to do dma mapping in advance v9: 1. use flag to distinguish the premapped operations. no do judgment by sg. v8: 1. vring_sg_address: check by sg_page(sg) not dma_address. Because 0 is a valid dma address 2. remove unused code from vring_map_one_sg() v7: 1. virtqueue_dma_dev() return NULL when virtio is without DMA API. v6: 1. change the size of the flags to u32. v5: 1. fix for error handler 2. add flags to record intern...

...ion of Virtio-Net, we also have to let virtio core support these features: 1. virtio core support premapped 2. virtio core support reset per-queue 3. introduce DMA APIs to virtio core Please review. Thanks. v9: 1. use flag to distinguish the premapped operations. no do judgment by sg. v8: 1. vring_sg_address: check by sg_page(sg) not dma_address. Because 0 is a valid dma address 2. remove unused code from vring_map_one_sg() v7: 1. virtqueue_dma_dev() return NULL when virtio is without DMA API. v6: 1. change the size of the flags to u32. v5: 1. fix for error handler 2. add flags to record intern...

...ed 2. A better way to handle the map error with the premapped v10: 1. support to set vq to premapped mode, then the vq just handles the premapped request. 2. virtio-net support to do dma mapping in advance v9: 1. use flag to distinguish the premapped operations. no do judgment by sg. v8: 1. vring_sg_address: check by sg_page(sg) not dma_address. Because 0 is a valid dma address 2. remove unused code from vring_map_one_sg() v7: 1. virtqueue_dma_dev() return NULL when virtio is without DMA API. v6: 1. change the size of the flags to u32. v5: 1. fix for error handler 2. add flags to record intern...