* Re: [RFC v2] virtio: support packed ring
From: Tiwei Bie @ 2018-04-10 3:21 UTC (permalink / raw)
To: Jason Wang; +Cc: mst, wexu, virtualization, linux-kernel, netdev, jfreimann
In-Reply-To: <5cf4d5d6-c416-28af-0568-750e9f654710@redhat.com>
On Tue, Apr 10, 2018 at 10:55:25AM +0800, Jason Wang wrote:
> On 2018年04月01日 22:12, Tiwei Bie wrote:
> > Hello everyone,
> >
> > This RFC implements packed ring support for virtio driver.
> >
> > The code was tested with DPDK vhost (testpmd/vhost-PMD) implemented
> > by Jens at http://dpdk.org/ml/archives/dev/2018-January/089417.html
> > Minor changes are needed for the vhost code, e.g. to kick the guest.
> >
> > TODO:
> > - Refinements and bug fixes;
> > - Split into small patches;
> > - Test indirect descriptor support;
> > - Test/fix event suppression support;
> > - Test devices other than net;
> >
> > RFC v1 -> RFC v2:
> > - Add indirect descriptor support - compile test only;
> > - Add event suppression supprt - compile test only;
> > - Move vring_packed_init() out of uapi (Jason, MST);
> > - Merge two loops into one in virtqueue_add_packed() (Jason);
> > - Split vring_unmap_one() for packed ring and split ring (Jason);
> > - Avoid using '%' operator (Jason);
> > - Rename free_head -> next_avail_idx (Jason);
> > - Add comments for virtio_wmb() in virtqueue_add_packed() (Jason);
> > - Some other refinements and bug fixes;
> >
> > Thanks!
>
> Will try to review this later.
>
> But it would be better if you can split it (more than 1000 lines is too big
> to be reviewed easily). E.g you can at least split it into three patches,
> new structures, datapath, and event suppression.
>
No problem! It's on my TODO list. I'll get it done in the next version.
Thanks!
^ permalink raw reply
* Re: [PATCH net-next 1/5] virtio: Add support for SCTP checksum offloading
From: Jason Wang @ 2018-04-10 3:17 UTC (permalink / raw)
To: Vladislav Yasevich, netdev
Cc: linux-sctp, virtualization, mst, nhorman, Vladislav Yasevich
In-Reply-To: <20180402134006.10111-2-vyasevic@redhat.com>
On 2018年04月02日 21:40, Vladislav Yasevich wrote:
> To support SCTP checksum offloading, we need to add a new feature
> to virtio_net, so we can negotiate support between the hypervisor
> and the guest.
>
> The signalling to the guest that an alternate checksum needs to
> be used is done via a new flag in the virtio_net_hdr. If the
> flag is set, the host will know to perform an alternate checksum
> calculation, which right now is only CRC32c.
>
> Signed-off-by: Vladislav Yasevich <vyasevic@redhat.com>
> ---
> drivers/net/virtio_net.c | 11 ++++++++---
> include/linux/virtio_net.h | 6 ++++++
> include/uapi/linux/virtio_net.h | 2 ++
> 3 files changed, 16 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 7b187ec..b601294 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -2724,9 +2724,14 @@ static int virtnet_probe(struct virtio_device *vdev)
> /* Do we support "hardware" checksums? */
> if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
> /* This opens up the world of extra features. */
> - dev->hw_features |= NETIF_F_HW_CSUM | NETIF_F_SG;
> + netdev_features_t sctp = 0;
> +
> + if (virtio_has_feature(vdev, VIRTIO_NET_F_SCTP_CSUM))
> + sctp |= NETIF_F_SCTP_CRC;
> +
> + dev->hw_features |= NETIF_F_HW_CSUM | NETIF_F_SG | sctp;
> if (csum)
> - dev->features |= NETIF_F_HW_CSUM | NETIF_F_SG;
> + dev->features |= NETIF_F_HW_CSUM | NETIF_F_SG | sctp;
>
> if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
> dev->hw_features |= NETIF_F_TSO
> @@ -2952,7 +2957,7 @@ static struct virtio_device_id id_table[] = {
> };
>
> #define VIRTNET_FEATURES \
> - VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, \
> + VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, VIRTIO_NET_F_SCTP_CSUM, \
It looks to me _F_SCTP_CSUM implies the ability of both device and
driver. Do we still need the flexibility like csum to differ guest/host
ability like e.g _F_GUEST_SCTP_CSUM?
Thanks
> VIRTIO_NET_F_MAC, \
> VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, \
> VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, \
> diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h
> index f144216..2e7a64a 100644
> --- a/include/linux/virtio_net.h
> +++ b/include/linux/virtio_net.h
> @@ -39,6 +39,9 @@ static inline int virtio_net_hdr_to_skb(struct sk_buff *skb,
>
> if (!skb_partial_csum_set(skb, start, off))
> return -EINVAL;
> +
> + if (hdr->flags & VIRTIO_NET_HDR_F_CSUM_NOT_INET)
> + skb->csum_not_inet = 1;
> }
>
> if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
> @@ -96,6 +99,9 @@ static inline int virtio_net_hdr_from_skb(const struct sk_buff *skb,
> hdr->flags = VIRTIO_NET_HDR_F_DATA_VALID;
> } /* else everything is zero */
>
> + if (skb->csum_not_inet)
> + hdr->flags &= VIRTIO_NET_HDR_F_CSUM_NOT_INET;
> +
> return 0;
> }
>
> diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h
> index 5de6ed3..3f279c8 100644
> --- a/include/uapi/linux/virtio_net.h
> +++ b/include/uapi/linux/virtio_net.h
> @@ -36,6 +36,7 @@
> #define VIRTIO_NET_F_GUEST_CSUM 1 /* Guest handles pkts w/ partial csum */
> #define VIRTIO_NET_F_CTRL_GUEST_OFFLOADS 2 /* Dynamic offload configuration. */
> #define VIRTIO_NET_F_MTU 3 /* Initial MTU advice */
> +#define VIRTIO_NET_F_SCTP_CSUM 4 /* SCTP checksum offload support */
> #define VIRTIO_NET_F_MAC 5 /* Host has given MAC address. */
> #define VIRTIO_NET_F_GUEST_TSO4 7 /* Guest can handle TSOv4 in. */
> #define VIRTIO_NET_F_GUEST_TSO6 8 /* Guest can handle TSOv6 in. */
> @@ -101,6 +102,7 @@ struct virtio_net_config {
> struct virtio_net_hdr_v1 {
> #define VIRTIO_NET_HDR_F_NEEDS_CSUM 1 /* Use csum_start, csum_offset */
> #define VIRTIO_NET_HDR_F_DATA_VALID 2 /* Csum is valid */
> +#define VIRTIO_NET_HDR_F_CSUM_NOT_INET 4 /* Checksum is not inet */
> __u8 flags;
> #define VIRTIO_NET_HDR_GSO_NONE 0 /* Not a GSO frame */
> #define VIRTIO_NET_HDR_GSO_TCPV4 1 /* GSO frame, IPv4 TCP (TSO) */
^ permalink raw reply
* Re: [Resend Patch 1/3] Vmbus: Add function to report available ring buffer to write in total ring size percentage
From: Martin K. Petersen @ 2018-04-10 2:58 UTC (permalink / raw)
To: Long Li
Cc: Stephen Hemminger, linux-scsi@vger.kernel.org, Martin K. Petersen,
netdev@vger.kernel.org, Haiyang Zhang, James E . J . Bottomley,
linux-kernel@vger.kernel.org, devel@linuxdriverproject.org,
Long Li
In-Reply-To: <MWHPR2101MB072958DDC25845615C3B1ADCCEA30@MWHPR2101MB0729.namprd21.prod.outlook.com>
Long,
> I hope this patch set goes through SCSI, because it's purpose is to
> improve storvsc.
>
> If this strategy is not possible, I can resubmit the 1st two patches to
> net, and the 3rd patch to scsi after the 1st two are merged.
Applied to my staging tree for 4.18/scsi-queue. Thanks!
--
Martin K. Petersen Oracle Linux Engineering
^ permalink raw reply
* Re: [RFC v2] virtio: support packed ring
From: Jason Wang @ 2018-04-10 2:55 UTC (permalink / raw)
To: Tiwei Bie, mst, wexu, virtualization, linux-kernel, netdev; +Cc: jfreimann
In-Reply-To: <20180401141216.8969-1-tiwei.bie@intel.com>
On 2018年04月01日 22:12, Tiwei Bie wrote:
> Hello everyone,
>
> This RFC implements packed ring support for virtio driver.
>
> The code was tested with DPDK vhost (testpmd/vhost-PMD) implemented
> by Jens at http://dpdk.org/ml/archives/dev/2018-January/089417.html
> Minor changes are needed for the vhost code, e.g. to kick the guest.
>
> TODO:
> - Refinements and bug fixes;
> - Split into small patches;
> - Test indirect descriptor support;
> - Test/fix event suppression support;
> - Test devices other than net;
>
> RFC v1 -> RFC v2:
> - Add indirect descriptor support - compile test only;
> - Add event suppression supprt - compile test only;
> - Move vring_packed_init() out of uapi (Jason, MST);
> - Merge two loops into one in virtqueue_add_packed() (Jason);
> - Split vring_unmap_one() for packed ring and split ring (Jason);
> - Avoid using '%' operator (Jason);
> - Rename free_head -> next_avail_idx (Jason);
> - Add comments for virtio_wmb() in virtqueue_add_packed() (Jason);
> - Some other refinements and bug fixes;
>
> Thanks!
Will try to review this later.
But it would be better if you can split it (more than 1000 lines is too
big to be reviewed easily). E.g you can at least split it into three
patches, new structures, datapath, and event suppression.
Thanks
>
> Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
> ---
> drivers/virtio/virtio_ring.c | 1094 +++++++++++++++++++++++++++++-------
> include/linux/virtio_ring.h | 8 +-
> include/uapi/linux/virtio_config.h | 12 +-
> include/uapi/linux/virtio_ring.h | 61 ++
> 4 files changed, 980 insertions(+), 195 deletions(-)
>
> diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> index 71458f493cf8..0515dca34d77 100644
> --- a/drivers/virtio/virtio_ring.c
> +++ b/drivers/virtio/virtio_ring.c
> @@ -58,14 +58,15 @@
>
> struct vring_desc_state {
> void *data; /* Data for callback. */
> - struct vring_desc *indir_desc; /* Indirect descriptor, if any. */
> + void *indir_desc; /* Indirect descriptor, if any. */
> + int num; /* Descriptor list length. */
> };
>
> struct vring_virtqueue {
> struct virtqueue vq;
>
> - /* Actual memory layout for this queue */
> - struct vring vring;
> + /* Is this a packed ring? */
> + bool packed;
>
> /* Can we use weak barriers? */
> bool weak_barriers;
> @@ -79,19 +80,45 @@ struct vring_virtqueue {
> /* Host publishes avail event idx */
> bool event;
>
> - /* Head of free buffer list. */
> - unsigned int free_head;
> /* Number we've added since last sync. */
> unsigned int num_added;
>
> /* Last used index we've seen. */
> u16 last_used_idx;
>
> - /* Last written value to avail->flags */
> - u16 avail_flags_shadow;
> + union {
> + /* Available for split ring */
> + struct {
> + /* Actual memory layout for this queue. */
> + struct vring vring;
>
> - /* Last written value to avail->idx in guest byte order */
> - u16 avail_idx_shadow;
> + /* Head of free buffer list. */
> + unsigned int free_head;
> +
> + /* Last written value to avail->flags */
> + u16 avail_flags_shadow;
> +
> + /* Last written value to avail->idx in
> + * guest byte order. */
> + u16 avail_idx_shadow;
> + };
> +
> + /* Available for packed ring */
> + struct {
> + /* Actual memory layout for this queue. */
> + struct vring_packed vring_packed;
> +
> + /* Driver ring wrap counter. */
> + u8 wrap_counter;
> +
> + /* Index of the next avail descriptor. */
> + unsigned int next_avail_idx;
> +
> + /* Last written value to driver->flags in
> + * guest byte order. */
> + u16 event_flags_shadow;
> + };
> + };
>
> /* How to notify other side. FIXME: commonalize hcalls! */
> bool (*notify)(struct virtqueue *vq);
> @@ -201,8 +228,33 @@ static dma_addr_t vring_map_single(const struct vring_virtqueue *vq,
> cpu_addr, size, direction);
> }
>
> -static void vring_unmap_one(const struct vring_virtqueue *vq,
> - struct vring_desc *desc)
> +static void vring_unmap_one_split(const struct vring_virtqueue *vq,
> + struct vring_desc *desc)
> +{
> + u16 flags;
> +
> + if (!vring_use_dma_api(vq->vq.vdev))
> + return;
> +
> + flags = virtio16_to_cpu(vq->vq.vdev, desc->flags);
> +
> + if (flags & VRING_DESC_F_INDIRECT) {
> + dma_unmap_single(vring_dma_dev(vq),
> + virtio64_to_cpu(vq->vq.vdev, desc->addr),
> + virtio32_to_cpu(vq->vq.vdev, desc->len),
> + (flags & VRING_DESC_F_WRITE) ?
> + DMA_FROM_DEVICE : DMA_TO_DEVICE);
> + } else {
> + dma_unmap_page(vring_dma_dev(vq),
> + virtio64_to_cpu(vq->vq.vdev, desc->addr),
> + virtio32_to_cpu(vq->vq.vdev, desc->len),
> + (flags & VRING_DESC_F_WRITE) ?
> + DMA_FROM_DEVICE : DMA_TO_DEVICE);
> + }
> +}
> +
> +static void vring_unmap_one_packed(const struct vring_virtqueue *vq,
> + struct vring_packed_desc *desc)
> {
> u16 flags;
>
> @@ -235,8 +287,9 @@ static int vring_mapping_error(const struct vring_virtqueue *vq,
> return dma_mapping_error(vring_dma_dev(vq), addr);
> }
>
> -static struct vring_desc *alloc_indirect(struct virtqueue *_vq,
> - unsigned int total_sg, gfp_t gfp)
> +static struct vring_desc *alloc_indirect_split(struct virtqueue *_vq,
> + unsigned int total_sg,
> + gfp_t gfp)
> {
> struct vring_desc *desc;
> unsigned int i;
> @@ -257,14 +310,32 @@ static struct vring_desc *alloc_indirect(struct virtqueue *_vq,
> return desc;
> }
>
> -static inline int virtqueue_add(struct virtqueue *_vq,
> - struct scatterlist *sgs[],
> - unsigned int total_sg,
> - unsigned int out_sgs,
> - unsigned int in_sgs,
> - void *data,
> - void *ctx,
> - gfp_t gfp)
> +static struct vring_packed_desc *alloc_indirect_packed(struct virtqueue *_vq,
> + unsigned int total_sg,
> + gfp_t gfp)
> +{
> + struct vring_packed_desc *desc;
> +
> + /*
> + * We require lowmem mappings for the descriptors because
> + * otherwise virt_to_phys will give us bogus addresses in the
> + * virtqueue.
> + */
> + gfp &= ~__GFP_HIGHMEM;
> +
> + desc = kmalloc(total_sg * sizeof(struct vring_packed_desc), gfp);
> +
> + return desc;
> +}
> +
> +static inline int virtqueue_add_split(struct virtqueue *_vq,
> + struct scatterlist *sgs[],
> + unsigned int total_sg,
> + unsigned int out_sgs,
> + unsigned int in_sgs,
> + void *data,
> + void *ctx,
> + gfp_t gfp)
> {
> struct vring_virtqueue *vq = to_vvq(_vq);
> struct scatterlist *sg;
> @@ -303,7 +374,7 @@ static inline int virtqueue_add(struct virtqueue *_vq,
> /* If the host supports indirect descriptor tables, and we have multiple
> * buffers, then go indirect. FIXME: tune this threshold */
> if (vq->indirect && total_sg > 1 && vq->vq.num_free)
> - desc = alloc_indirect(_vq, total_sg, gfp);
> + desc = alloc_indirect_split(_vq, total_sg, gfp);
> else {
> desc = NULL;
> WARN_ON_ONCE(total_sg > vq->vring.num && !vq->indirect);
> @@ -424,7 +495,7 @@ static inline int virtqueue_add(struct virtqueue *_vq,
> for (n = 0; n < total_sg; n++) {
> if (i == err_idx)
> break;
> - vring_unmap_one(vq, &desc[i]);
> + vring_unmap_one_split(vq, &desc[i]);
> i = virtio16_to_cpu(_vq->vdev, vq->vring.desc[i].next);
> }
>
> @@ -435,6 +506,210 @@ static inline int virtqueue_add(struct virtqueue *_vq,
> return -EIO;
> }
>
> +static inline int virtqueue_add_packed(struct virtqueue *_vq,
> + struct scatterlist *sgs[],
> + unsigned int total_sg,
> + unsigned int out_sgs,
> + unsigned int in_sgs,
> + void *data,
> + void *ctx,
> + gfp_t gfp)
> +{
> + struct vring_virtqueue *vq = to_vvq(_vq);
> + struct vring_packed_desc *desc;
> + struct scatterlist *sg;
> + unsigned int i, n, descs_used, uninitialized_var(prev), err_idx;
> + __virtio16 uninitialized_var(head_flags), flags;
> + int head, wrap_counter;
> + bool indirect;
> +
> + START_USE(vq);
> +
> + BUG_ON(data == NULL);
> + BUG_ON(ctx && vq->indirect);
> +
> + if (unlikely(vq->broken)) {
> + END_USE(vq);
> + return -EIO;
> + }
> +
> +#ifdef DEBUG
> + {
> + ktime_t now = ktime_get();
> +
> + /* No kick or get, with .1 second between? Warn. */
> + if (vq->last_add_time_valid)
> + WARN_ON(ktime_to_ms(ktime_sub(now, vq->last_add_time))
> + > 100);
> + vq->last_add_time = now;
> + vq->last_add_time_valid = true;
> + }
> +#endif
> +
> + BUG_ON(total_sg == 0);
> +
> + head = vq->next_avail_idx;
> + wrap_counter = vq->wrap_counter;
> +
> + /* If the host supports indirect descriptor tables, and we have multiple
> + * buffers, then go indirect. FIXME: tune this threshold */
> + if (vq->indirect && total_sg > 1 && vq->vq.num_free)
> + desc = alloc_indirect_packed(_vq, total_sg, gfp);
> + else {
> + desc = NULL;
> + WARN_ON_ONCE(total_sg > vq->vring_packed.num && !vq->indirect);
> + }
> +
> + if (desc) {
> + /* Use a single buffer which doesn't continue */
> + indirect = true;
> + /* Set up rest to use this indirect table. */
> + i = 0;
> + descs_used = 1;
> + } else {
> + indirect = false;
> + desc = vq->vring_packed.desc;
> + i = head;
> + descs_used = total_sg;
> + }
> +
> + if (vq->vq.num_free < descs_used) {
> + pr_debug("Can't add buf len %i - avail = %i\n",
> + descs_used, vq->vq.num_free);
> + /* FIXME: for historical reasons, we force a notify here if
> + * there are outgoing parts to the buffer. Presumably the
> + * host should service the ring ASAP. */
> + if (out_sgs)
> + vq->notify(&vq->vq);
> + if (indirect)
> + kfree(desc);
> + END_USE(vq);
> + return -ENOSPC;
> + }
> +
> + for (n = 0; n < out_sgs + in_sgs; n++) {
> + for (sg = sgs[n]; sg; sg = sg_next(sg)) {
> + dma_addr_t addr = vring_map_one_sg(vq, sg, n < out_sgs ?
> + DMA_TO_DEVICE : DMA_FROM_DEVICE);
> + if (vring_mapping_error(vq, addr))
> + goto unmap_release;
> +
> + flags = cpu_to_virtio16(_vq->vdev, VRING_DESC_F_NEXT |
> + (n < out_sgs ? 0 : VRING_DESC_F_WRITE) |
> + VRING_DESC_F_AVAIL(vq->wrap_counter) |
> + VRING_DESC_F_USED(!vq->wrap_counter));
> + if (!indirect && i == head)
> + head_flags = flags;
> + else
> + desc[i].flags = flags;
> +
> + desc[i].addr = cpu_to_virtio64(_vq->vdev, addr);
> + desc[i].len = cpu_to_virtio32(_vq->vdev, sg->length);
> + desc[i].id = cpu_to_virtio32(_vq->vdev, head);
> + prev = i;
> + i++;
> + if (!indirect && i >= vq->vring_packed.num) {
> + i = 0;
> + vq->wrap_counter ^= 1;
> + }
> + }
> + }
> + /* Last one doesn't continue. */
> + if (total_sg == 1)
> + head_flags &= cpu_to_virtio16(_vq->vdev, ~VRING_DESC_F_NEXT);
> + else
> + desc[prev].flags &= cpu_to_virtio16(_vq->vdev, ~VRING_DESC_F_NEXT);
> +
> + if (indirect) {
> + /* Now that the indirect table is filled in, map it. */
> + dma_addr_t addr = vring_map_single(
> + vq, desc, total_sg * sizeof(struct vring_packed_desc),
> + DMA_TO_DEVICE);
> + if (vring_mapping_error(vq, addr))
> + goto unmap_release;
> +
> + head_flags = cpu_to_virtio16(_vq->vdev, VRING_DESC_F_INDIRECT |
> + VRING_DESC_F_AVAIL(wrap_counter) |
> + VRING_DESC_F_USED(!wrap_counter));
> + vq->vring_packed.desc[head].addr = cpu_to_virtio64(_vq->vdev, addr);
> + vq->vring_packed.desc[head].len = cpu_to_virtio32(_vq->vdev,
> + total_sg * sizeof(struct vring_packed_desc));
> + vq->vring_packed.desc[head].id = cpu_to_virtio32(_vq->vdev, head);
> + }
> +
> + /* We're using some buffers from the free list. */
> + vq->vq.num_free -= descs_used;
> +
> + /* Update free pointer */
> + if (indirect) {
> + n = head + 1;
> + if (n >= vq->vring_packed.num) {
> + n = 0;
> + vq->wrap_counter ^= 1;
> + }
> + vq->next_avail_idx = n;
> + } else
> + vq->next_avail_idx = i;
> +
> + /* Store token and indirect buffer state. */
> + vq->desc_state[head].num = descs_used;
> + vq->desc_state[head].data = data;
> + if (indirect)
> + vq->desc_state[head].indir_desc = desc;
> + else
> + vq->desc_state[head].indir_desc = ctx;
> +
> + /* A driver MUST NOT make the first descriptor in the list
> + * available before all subsequent descriptors comprising
> + * the list are made available. */
> + virtio_wmb(vq->weak_barriers);
> + vq->vring_packed.desc[head].flags = head_flags;
> + vq->num_added++;
> +
> + pr_debug("Added buffer head %i to %p\n", head, vq);
> + END_USE(vq);
> +
> + return 0;
> +
> +unmap_release:
> + err_idx = i;
> + i = head;
> +
> + for (n = 0; n < total_sg; n++) {
> + if (i == err_idx)
> + break;
> + vring_unmap_one_packed(vq, &desc[i]);
> + i++;
> + if (!indirect && i >= vq->vring_packed.num)
> + i = 0;
> + }
> +
> + vq->wrap_counter = wrap_counter;
> +
> + if (indirect)
> + kfree(desc);
> +
> + END_USE(vq);
> + return -EIO;
> +}
> +
> +static inline int virtqueue_add(struct virtqueue *_vq,
> + struct scatterlist *sgs[],
> + unsigned int total_sg,
> + unsigned int out_sgs,
> + unsigned int in_sgs,
> + void *data,
> + void *ctx,
> + gfp_t gfp)
> +{
> + struct vring_virtqueue *vq = to_vvq(_vq);
> +
> + return vq->packed ? virtqueue_add_packed(_vq, sgs, total_sg, out_sgs,
> + in_sgs, data, ctx, gfp) :
> + virtqueue_add_split(_vq, sgs, total_sg, out_sgs,
> + in_sgs, data, ctx, gfp);
> +}
> +
> /**
> * virtqueue_add_sgs - expose buffers to other end
> * @vq: the struct virtqueue we're talking about.
> @@ -537,18 +812,7 @@ int virtqueue_add_inbuf_ctx(struct virtqueue *vq,
> }
> EXPORT_SYMBOL_GPL(virtqueue_add_inbuf_ctx);
>
> -/**
> - * virtqueue_kick_prepare - first half of split virtqueue_kick call.
> - * @vq: the struct virtqueue
> - *
> - * Instead of virtqueue_kick(), you can do:
> - * if (virtqueue_kick_prepare(vq))
> - * virtqueue_notify(vq);
> - *
> - * This is sometimes useful because the virtqueue_kick_prepare() needs
> - * to be serialized, but the actual virtqueue_notify() call does not.
> - */
> -bool virtqueue_kick_prepare(struct virtqueue *_vq)
> +static bool virtqueue_kick_prepare_split(struct virtqueue *_vq)
> {
> struct vring_virtqueue *vq = to_vvq(_vq);
> u16 new, old;
> @@ -580,6 +844,62 @@ bool virtqueue_kick_prepare(struct virtqueue *_vq)
> END_USE(vq);
> return needs_kick;
> }
> +
> +static bool virtqueue_kick_prepare_packed(struct virtqueue *_vq)
> +{
> + struct vring_virtqueue *vq = to_vvq(_vq);
> + u16 new, old, off_wrap;
> + bool needs_kick;
> +
> + START_USE(vq);
> + /* We need to expose the new flags value before checking notification
> + * suppressions. */
> + virtio_mb(vq->weak_barriers);
> +
> + old = vq->next_avail_idx - vq->num_added;
> + new = vq->next_avail_idx;
> + vq->num_added = 0;
> +
> +#ifdef DEBUG
> + if (vq->last_add_time_valid) {
> + WARN_ON(ktime_to_ms(ktime_sub(ktime_get(),
> + vq->last_add_time)) > 100);
> + }
> + vq->last_add_time_valid = false;
> +#endif
> +
> + off_wrap = virtio16_to_cpu(_vq->vdev, vq->vring_packed.device->off_wrap);
> +
> + if (vq->event) {
> + // FIXME: fix this!
> + needs_kick = ((off_wrap >> 15) == vq->wrap_counter) &&
> + vring_need_event(off_wrap & ~(1<<15), new, old);
> + } else {
> + needs_kick = (vq->vring_packed.device->flags !=
> + cpu_to_virtio16(_vq->vdev, VRING_EVENT_F_DISABLE));
> + }
> + END_USE(vq);
> + return needs_kick;
> +}
> +
> +/**
> + * virtqueue_kick_prepare - first half of split virtqueue_kick call.
> + * @vq: the struct virtqueue
> + *
> + * Instead of virtqueue_kick(), you can do:
> + * if (virtqueue_kick_prepare(vq))
> + * virtqueue_notify(vq);
> + *
> + * This is sometimes useful because the virtqueue_kick_prepare() needs
> + * to be serialized, but the actual virtqueue_notify() call does not.
> + */
> +bool virtqueue_kick_prepare(struct virtqueue *_vq)
> +{
> + struct vring_virtqueue *vq = to_vvq(_vq);
> +
> + return vq->packed ? virtqueue_kick_prepare_packed(_vq) :
> + virtqueue_kick_prepare_split(_vq);
> +}
> EXPORT_SYMBOL_GPL(virtqueue_kick_prepare);
>
> /**
> @@ -626,8 +946,8 @@ bool virtqueue_kick(struct virtqueue *vq)
> }
> EXPORT_SYMBOL_GPL(virtqueue_kick);
>
> -static void detach_buf(struct vring_virtqueue *vq, unsigned int head,
> - void **ctx)
> +static void detach_buf_split(struct vring_virtqueue *vq, unsigned int head,
> + void **ctx)
> {
> unsigned int i, j;
> __virtio16 nextflag = cpu_to_virtio16(vq->vq.vdev, VRING_DESC_F_NEXT);
> @@ -639,12 +959,12 @@ static void detach_buf(struct vring_virtqueue *vq, unsigned int head,
> i = head;
>
> while (vq->vring.desc[i].flags & nextflag) {
> - vring_unmap_one(vq, &vq->vring.desc[i]);
> + vring_unmap_one_split(vq, &vq->vring.desc[i]);
> i = virtio16_to_cpu(vq->vq.vdev, vq->vring.desc[i].next);
> vq->vq.num_free++;
> }
>
> - vring_unmap_one(vq, &vq->vring.desc[i]);
> + vring_unmap_one_split(vq, &vq->vring.desc[i]);
> vq->vring.desc[i].next = cpu_to_virtio16(vq->vq.vdev, vq->free_head);
> vq->free_head = head;
>
> @@ -666,7 +986,7 @@ static void detach_buf(struct vring_virtqueue *vq, unsigned int head,
> BUG_ON(len == 0 || len % sizeof(struct vring_desc));
>
> for (j = 0; j < len / sizeof(struct vring_desc); j++)
> - vring_unmap_one(vq, &indir_desc[j]);
> + vring_unmap_one_split(vq, &indir_desc[j]);
>
> kfree(indir_desc);
> vq->desc_state[head].indir_desc = NULL;
> @@ -675,11 +995,207 @@ static void detach_buf(struct vring_virtqueue *vq, unsigned int head,
> }
> }
>
> -static inline bool more_used(const struct vring_virtqueue *vq)
> +static int detach_buf_packed(struct vring_virtqueue *vq, unsigned int head,
> + void **ctx)
> +{
> + struct vring_packed_desc *desc;
> + unsigned int i, j;
> +
> + /* Clear data ptr. */
> + vq->desc_state[head].data = NULL;
> +
> + i = head;
> +
> + for (j = 0; j < vq->desc_state[head].num; j++) {
> + desc = &vq->vring_packed.desc[i];
> + vring_unmap_one_packed(vq, desc);
> + desc->flags = 0x0;
> + i++;
> + if (i >= vq->vring_packed.num)
> + i = 0;
> + }
> +
> + vq->vq.num_free += vq->desc_state[head].num;
> +
> + if (vq->indirect) {
> + u32 len;
> +
> + desc = vq->desc_state[head].indir_desc;
> + /* Free the indirect table, if any, now that it's unmapped. */
> + if (!desc)
> + goto out;
> +
> + len = virtio32_to_cpu(vq->vq.vdev,
> + vq->vring_packed.desc[head].len);
> +
> + BUG_ON(!(vq->vring_packed.desc[head].flags &
> + cpu_to_virtio16(vq->vq.vdev, VRING_DESC_F_INDIRECT)));
> + BUG_ON(len == 0 || len % sizeof(struct vring_packed_desc));
> +
> + for (j = 0; j < len / sizeof(struct vring_packed_desc); j++)
> + vring_unmap_one_packed(vq, &desc[j]);
> +
> + kfree(desc);
> + vq->desc_state[head].indir_desc = NULL;
> + } else if (ctx) {
> + *ctx = vq->desc_state[head].indir_desc;
> + }
> +
> +out:
> + return vq->desc_state[head].num;
> +}
> +
> +static inline bool more_used_split(const struct vring_virtqueue *vq)
> {
> return vq->last_used_idx != virtio16_to_cpu(vq->vq.vdev, vq->vring.used->idx);
> }
>
> +static inline bool more_used_packed(const struct vring_virtqueue *vq)
> +{
> + u16 last_used, flags;
> + bool avail, used;
> +
> + if (vq->vq.num_free == vq->vring_packed.num)
> + return false;
> +
> + last_used = vq->last_used_idx;
> + flags = virtio16_to_cpu(vq->vq.vdev,
> + vq->vring_packed.desc[last_used].flags);
> + avail = flags & VRING_DESC_F_AVAIL(1);
> + used = flags & VRING_DESC_F_USED(1);
> +
> + return avail == used;
> +}
> +
> +static inline bool more_used(const struct vring_virtqueue *vq)
> +{
> + return vq->packed ? more_used_packed(vq) : more_used_split(vq);
> +}
> +
> +void *virtqueue_get_buf_ctx_split(struct virtqueue *_vq, unsigned int *len,
> + void **ctx)
> +{
> + struct vring_virtqueue *vq = to_vvq(_vq);
> + void *ret;
> + unsigned int i;
> + u16 last_used;
> +
> + START_USE(vq);
> +
> + if (unlikely(vq->broken)) {
> + END_USE(vq);
> + return NULL;
> + }
> +
> + if (!more_used(vq)) {
> + pr_debug("No more buffers in queue\n");
> + END_USE(vq);
> + return NULL;
> + }
> +
> + /* Only get used array entries after they have been exposed by host. */
> + virtio_rmb(vq->weak_barriers);
> +
> + last_used = (vq->last_used_idx & (vq->vring.num - 1));
> + i = virtio32_to_cpu(_vq->vdev, vq->vring.used->ring[last_used].id);
> + *len = virtio32_to_cpu(_vq->vdev, vq->vring.used->ring[last_used].len);
> +
> + if (unlikely(i >= vq->vring.num)) {
> + BAD_RING(vq, "id %u out of range\n", i);
> + return NULL;
> + }
> + if (unlikely(!vq->desc_state[i].data)) {
> + BAD_RING(vq, "id %u is not a head!\n", i);
> + return NULL;
> + }
> +
> + /* detach_buf_split clears data, so grab it now. */
> + ret = vq->desc_state[i].data;
> + detach_buf_split(vq, i, ctx);
> + vq->last_used_idx++;
> + /* If we expect an interrupt for the next entry, tell host
> + * by writing event index and flush out the write before
> + * the read in the next get_buf call. */
> + if (!(vq->avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT))
> + virtio_store_mb(vq->weak_barriers,
> + &vring_used_event(&vq->vring),
> + cpu_to_virtio16(_vq->vdev, vq->last_used_idx));
> +
> +#ifdef DEBUG
> + vq->last_add_time_valid = false;
> +#endif
> +
> + END_USE(vq);
> + return ret;
> +}
> +
> +void *virtqueue_get_buf_ctx_packed(struct virtqueue *_vq, unsigned int *len,
> + void **ctx)
> +{
> + struct vring_virtqueue *vq = to_vvq(_vq);
> + uint16_t wrap_counter;
> + void *ret;
> + unsigned int i;
> + u16 last_used;
> +
> + START_USE(vq);
> +
> + if (unlikely(vq->broken)) {
> + END_USE(vq);
> + return NULL;
> + }
> +
> + if (!more_used(vq)) {
> + pr_debug("No more buffers in queue\n");
> + END_USE(vq);
> + return NULL;
> + }
> +
> + /* Only get used elements after they have been exposed by host. */
> + virtio_rmb(vq->weak_barriers);
> +
> + last_used = vq->last_used_idx;
> + i = virtio32_to_cpu(_vq->vdev, vq->vring_packed.desc[last_used].id);
> + *len = virtio32_to_cpu(_vq->vdev, vq->vring_packed.desc[last_used].len);
> +
> + if (unlikely(i >= vq->vring_packed.num)) {
> + BAD_RING(vq, "id %u out of range\n", i);
> + return NULL;
> + }
> + if (unlikely(!vq->desc_state[i].data)) {
> + BAD_RING(vq, "id %u is not a head!\n", i);
> + return NULL;
> + }
> +
> + /* detach_buf_packed clears data, so grab it now. */
> + ret = vq->desc_state[i].data;
> + detach_buf_packed(vq, i, ctx);
> +
> + vq->last_used_idx += vq->desc_state[i].num;
> + if (vq->last_used_idx >= vq->vring_packed.num)
> + vq->last_used_idx -= vq->vring_packed.num;
> +
> + wrap_counter = vq->wrap_counter;
> + if (vq->last_used_idx > vq->next_avail_idx)
> + wrap_counter ^= 1;
> +
> + /* If we expect an interrupt for the next entry, tell host
> + * by writing event index and flush out the write before
> + * the read in the next get_buf call. */
> + if (vq->event_flags_shadow == VRING_EVENT_F_DESC)
> + virtio_store_mb(vq->weak_barriers,
> + &vq->vring_packed.driver->off_wrap,
> + cpu_to_virtio16(_vq->vdev, vq->last_used_idx |
> + wrap_counter << 15));
> +
> +#ifdef DEBUG
> + vq->last_add_time_valid = false;
> +#endif
> +
> + END_USE(vq);
> + return ret;
> +}
> +
> /**
> * virtqueue_get_buf - get the next used buffer
> * @vq: the struct virtqueue we're talking about.
> @@ -700,57 +1216,9 @@ void *virtqueue_get_buf_ctx(struct virtqueue *_vq, unsigned int *len,
> void **ctx)
> {
> struct vring_virtqueue *vq = to_vvq(_vq);
> - void *ret;
> - unsigned int i;
> - u16 last_used;
>
> - START_USE(vq);
> -
> - if (unlikely(vq->broken)) {
> - END_USE(vq);
> - return NULL;
> - }
> -
> - if (!more_used(vq)) {
> - pr_debug("No more buffers in queue\n");
> - END_USE(vq);
> - return NULL;
> - }
> -
> - /* Only get used array entries after they have been exposed by host. */
> - virtio_rmb(vq->weak_barriers);
> -
> - last_used = (vq->last_used_idx & (vq->vring.num - 1));
> - i = virtio32_to_cpu(_vq->vdev, vq->vring.used->ring[last_used].id);
> - *len = virtio32_to_cpu(_vq->vdev, vq->vring.used->ring[last_used].len);
> -
> - if (unlikely(i >= vq->vring.num)) {
> - BAD_RING(vq, "id %u out of range\n", i);
> - return NULL;
> - }
> - if (unlikely(!vq->desc_state[i].data)) {
> - BAD_RING(vq, "id %u is not a head!\n", i);
> - return NULL;
> - }
> -
> - /* detach_buf clears data, so grab it now. */
> - ret = vq->desc_state[i].data;
> - detach_buf(vq, i, ctx);
> - vq->last_used_idx++;
> - /* If we expect an interrupt for the next entry, tell host
> - * by writing event index and flush out the write before
> - * the read in the next get_buf call. */
> - if (!(vq->avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT))
> - virtio_store_mb(vq->weak_barriers,
> - &vring_used_event(&vq->vring),
> - cpu_to_virtio16(_vq->vdev, vq->last_used_idx));
> -
> -#ifdef DEBUG
> - vq->last_add_time_valid = false;
> -#endif
> -
> - END_USE(vq);
> - return ret;
> + return vq->packed ? virtqueue_get_buf_ctx_packed(_vq, len, ctx) :
> + virtqueue_get_buf_ctx_split(_vq, len, ctx);
> }
> EXPORT_SYMBOL_GPL(virtqueue_get_buf_ctx);
>
> @@ -759,6 +1227,29 @@ void *virtqueue_get_buf(struct virtqueue *_vq, unsigned int *len)
> return virtqueue_get_buf_ctx(_vq, len, NULL);
> }
> EXPORT_SYMBOL_GPL(virtqueue_get_buf);
> +
> +static void virtqueue_disable_cb_split(struct virtqueue *_vq)
> +{
> + struct vring_virtqueue *vq = to_vvq(_vq);
> +
> + if (!(vq->avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT)) {
> + vq->avail_flags_shadow |= VRING_AVAIL_F_NO_INTERRUPT;
> + if (!vq->event)
> + vq->vring.avail->flags = cpu_to_virtio16(_vq->vdev, vq->avail_flags_shadow);
> + }
> +}
> +
> +static void virtqueue_disable_cb_packed(struct virtqueue *_vq)
> +{
> + struct vring_virtqueue *vq = to_vvq(_vq);
> +
> + if (vq->event_flags_shadow != VRING_EVENT_F_DISABLE) {
> + vq->event_flags_shadow = VRING_EVENT_F_DISABLE;
> + vq->vring_packed.driver->flags = cpu_to_virtio16(_vq->vdev,
> + vq->event_flags_shadow);
> + }
> +}
> +
> /**
> * virtqueue_disable_cb - disable callbacks
> * @vq: the struct virtqueue we're talking about.
> @@ -772,15 +1263,66 @@ void virtqueue_disable_cb(struct virtqueue *_vq)
> {
> struct vring_virtqueue *vq = to_vvq(_vq);
>
> - if (!(vq->avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT)) {
> - vq->avail_flags_shadow |= VRING_AVAIL_F_NO_INTERRUPT;
> - if (!vq->event)
> - vq->vring.avail->flags = cpu_to_virtio16(_vq->vdev, vq->avail_flags_shadow);
> - }
> -
> + if (vq->packed)
> + virtqueue_disable_cb_packed(_vq);
> + else
> + virtqueue_disable_cb_split(_vq);
> }
> EXPORT_SYMBOL_GPL(virtqueue_disable_cb);
>
> +static unsigned virtqueue_enable_cb_prepare_split(struct virtqueue *_vq)
> +{
> + struct vring_virtqueue *vq = to_vvq(_vq);
> + u16 last_used_idx;
> +
> + START_USE(vq);
> +
> + /* We optimistically turn back on interrupts, then check if there was
> + * more to do. */
> + /* Depending on the VIRTIO_RING_F_EVENT_IDX feature, we need to
> + * either clear the flags bit or point the event index at the next
> + * entry. Always do both to keep code simple. */
> + if (vq->avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT) {
> + vq->avail_flags_shadow &= ~VRING_AVAIL_F_NO_INTERRUPT;
> + if (!vq->event)
> + vq->vring.avail->flags = cpu_to_virtio16(_vq->vdev, vq->avail_flags_shadow);
> + }
> + vring_used_event(&vq->vring) = cpu_to_virtio16(_vq->vdev, last_used_idx = vq->last_used_idx);
> + END_USE(vq);
> + return last_used_idx;
> +}
> +
> +static unsigned virtqueue_enable_cb_prepare_packed(struct virtqueue *_vq)
> +{
> + struct vring_virtqueue *vq = to_vvq(_vq);
> + u16 last_used_idx, wrap_counter, off_wrap;
> +
> + START_USE(vq);
> +
> + last_used_idx = vq->last_used_idx;
> + wrap_counter = vq->wrap_counter;
> +
> + if (last_used_idx > vq->next_avail_idx)
> + wrap_counter ^= 1;
> +
> + off_wrap = last_used_idx | (wrap_counter << 15);
> +
> + /* We optimistically turn back on interrupts, then check if there was
> + * more to do. */
> + /* Depending on the VIRTIO_RING_F_EVENT_IDX feature, we need to
> + * either clear the flags bit or point the event index at the next
> + * entry. Always do both to keep code simple. */
> + if (vq->event_flags_shadow == VRING_EVENT_F_DISABLE) {
> + vq->event_flags_shadow = vq->event ? VRING_EVENT_F_DESC:
> + VRING_EVENT_F_ENABLE;
> + vq->vring_packed.driver->flags = cpu_to_virtio16(_vq->vdev,
> + vq->event_flags_shadow);
> + }
> + vq->vring_packed.driver->off_wrap = cpu_to_virtio16(_vq->vdev, off_wrap);
> + END_USE(vq);
> + return last_used_idx;
> +}
> +
> /**
> * virtqueue_enable_cb_prepare - restart callbacks after disable_cb
> * @vq: the struct virtqueue we're talking about.
> @@ -796,26 +1338,34 @@ EXPORT_SYMBOL_GPL(virtqueue_disable_cb);
> unsigned virtqueue_enable_cb_prepare(struct virtqueue *_vq)
> {
> struct vring_virtqueue *vq = to_vvq(_vq);
> - u16 last_used_idx;
>
> - START_USE(vq);
> -
> - /* We optimistically turn back on interrupts, then check if there was
> - * more to do. */
> - /* Depending on the VIRTIO_RING_F_EVENT_IDX feature, we need to
> - * either clear the flags bit or point the event index at the next
> - * entry. Always do both to keep code simple. */
> - if (vq->avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT) {
> - vq->avail_flags_shadow &= ~VRING_AVAIL_F_NO_INTERRUPT;
> - if (!vq->event)
> - vq->vring.avail->flags = cpu_to_virtio16(_vq->vdev, vq->avail_flags_shadow);
> - }
> - vring_used_event(&vq->vring) = cpu_to_virtio16(_vq->vdev, last_used_idx = vq->last_used_idx);
> - END_USE(vq);
> - return last_used_idx;
> + return vq->packed ? virtqueue_enable_cb_prepare_packed(_vq) :
> + virtqueue_enable_cb_prepare_split(_vq);
> }
> EXPORT_SYMBOL_GPL(virtqueue_enable_cb_prepare);
>
> +static bool virtqueue_poll_split(struct virtqueue *_vq, unsigned last_used_idx)
> +{
> + struct vring_virtqueue *vq = to_vvq(_vq);
> +
> + virtio_mb(vq->weak_barriers);
> + return (u16)last_used_idx != virtio16_to_cpu(_vq->vdev, vq->vring.used->idx);
> +}
> +
> +static bool virtqueue_poll_packed(struct virtqueue *_vq, unsigned last_used_idx)
> +{
> + struct vring_virtqueue *vq = to_vvq(_vq);
> + bool avail, used;
> + u16 flags;
> +
> + virtio_mb(vq->weak_barriers);
> + flags = virtio16_to_cpu(vq->vq.vdev,
> + vq->vring_packed.desc[last_used_idx].flags);
> + avail = flags & VRING_DESC_F_AVAIL(1);
> + used = flags & VRING_DESC_F_USED(1);
> + return avail == used;
> +}
> +
> /**
> * virtqueue_poll - query pending used buffers
> * @vq: the struct virtqueue we're talking about.
> @@ -829,8 +1379,8 @@ bool virtqueue_poll(struct virtqueue *_vq, unsigned last_used_idx)
> {
> struct vring_virtqueue *vq = to_vvq(_vq);
>
> - virtio_mb(vq->weak_barriers);
> - return (u16)last_used_idx != virtio16_to_cpu(_vq->vdev, vq->vring.used->idx);
> + return vq->packed ? virtqueue_poll_packed(_vq, last_used_idx) :
> + virtqueue_poll_split(_vq, last_used_idx);
> }
> EXPORT_SYMBOL_GPL(virtqueue_poll);
>
> @@ -852,6 +1402,83 @@ bool virtqueue_enable_cb(struct virtqueue *_vq)
> }
> EXPORT_SYMBOL_GPL(virtqueue_enable_cb);
>
> +static bool virtqueue_enable_cb_delayed_split(struct virtqueue *_vq)
> +{
> + struct vring_virtqueue *vq = to_vvq(_vq);
> + u16 bufs;
> +
> + START_USE(vq);
> +
> + /* We optimistically turn back on interrupts, then check if there was
> + * more to do. */
> + /* Depending on the VIRTIO_RING_F_USED_EVENT_IDX feature, we need to
> + * either clear the flags bit or point the event index at the next
> + * entry. Always update the event index to keep code simple. */
> + if (vq->avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT) {
> + vq->avail_flags_shadow &= ~VRING_AVAIL_F_NO_INTERRUPT;
> + if (!vq->event)
> + vq->vring.avail->flags = cpu_to_virtio16(_vq->vdev, vq->avail_flags_shadow);
> + }
> + /* TODO: tune this threshold */
> + bufs = (u16)(vq->avail_idx_shadow - vq->last_used_idx) * 3 / 4;
> +
> + virtio_store_mb(vq->weak_barriers,
> + &vring_used_event(&vq->vring),
> + cpu_to_virtio16(_vq->vdev, vq->last_used_idx + bufs));
> +
> + if (unlikely((u16)(virtio16_to_cpu(_vq->vdev, vq->vring.used->idx) - vq->last_used_idx) > bufs)) {
> + END_USE(vq);
> + return false;
> + }
> +
> + END_USE(vq);
> + return true;
> +}
> +
> +static bool virtqueue_enable_cb_delayed_packed(struct virtqueue *_vq)
> +{
> + struct vring_virtqueue *vq = to_vvq(_vq);
> + u16 bufs, off_wrap, used_idx, wrap_counter;
> +
> + START_USE(vq);
> +
> + /* We optimistically turn back on interrupts, then check if there was
> + * more to do. */
> + /* Depending on the VIRTIO_RING_F_USED_EVENT_IDX feature, we need to
> + * either clear the flags bit or point the event index at the next
> + * entry. Always update the event index to keep code simple. */
> + if (vq->event_flags_shadow == VRING_EVENT_F_DISABLE) {
> + vq->event_flags_shadow = vq->event ? VRING_EVENT_F_DESC:
> + VRING_EVENT_F_ENABLE;
> + vq->vring_packed.driver->flags = cpu_to_virtio16(_vq->vdev,
> + vq->event_flags_shadow);
> + }
> +
> + /* TODO: tune this threshold */
> + bufs = (u16)(vq->next_avail_idx - vq->last_used_idx) * 3 / 4;
> +
> + used_idx = vq->last_used_idx + bufs;
> + if (used_idx >= vq->vring_packed.num)
> + used_idx -= vq->vring_packed.num;
> +
> + wrap_counter = vq->wrap_counter;
> + if (used_idx > vq->next_avail_idx)
> + wrap_counter ^= 1;
> +
> + off_wrap = used_idx | (wrap_counter << 15);
> +
> + virtio_store_mb(vq->weak_barriers, &vq->vring_packed.driver->off_wrap,
> + cpu_to_virtio16(_vq->vdev, off_wrap));
> +
> + if (more_used_packed(vq)) {
> + END_USE(vq);
> + return false;
> + }
> +
> + END_USE(vq);
> + return true;
> +}
> +
> /**
> * virtqueue_enable_cb_delayed - restart callbacks after disable_cb.
> * @vq: the struct virtqueue we're talking about.
> @@ -868,37 +1495,69 @@ EXPORT_SYMBOL_GPL(virtqueue_enable_cb);
> bool virtqueue_enable_cb_delayed(struct virtqueue *_vq)
> {
> struct vring_virtqueue *vq = to_vvq(_vq);
> - u16 bufs;
>
> - START_USE(vq);
> -
> - /* We optimistically turn back on interrupts, then check if there was
> - * more to do. */
> - /* Depending on the VIRTIO_RING_F_USED_EVENT_IDX feature, we need to
> - * either clear the flags bit or point the event index at the next
> - * entry. Always update the event index to keep code simple. */
> - if (vq->avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT) {
> - vq->avail_flags_shadow &= ~VRING_AVAIL_F_NO_INTERRUPT;
> - if (!vq->event)
> - vq->vring.avail->flags = cpu_to_virtio16(_vq->vdev, vq->avail_flags_shadow);
> - }
> - /* TODO: tune this threshold */
> - bufs = (u16)(vq->avail_idx_shadow - vq->last_used_idx) * 3 / 4;
> -
> - virtio_store_mb(vq->weak_barriers,
> - &vring_used_event(&vq->vring),
> - cpu_to_virtio16(_vq->vdev, vq->last_used_idx + bufs));
> -
> - if (unlikely((u16)(virtio16_to_cpu(_vq->vdev, vq->vring.used->idx) - vq->last_used_idx) > bufs)) {
> - END_USE(vq);
> - return false;
> - }
> -
> - END_USE(vq);
> - return true;
> + return vq->packed ? virtqueue_enable_cb_delayed_packed(_vq) :
> + virtqueue_enable_cb_delayed_split(_vq);
> }
> EXPORT_SYMBOL_GPL(virtqueue_enable_cb_delayed);
>
> +static void *virtqueue_detach_unused_buf_split(struct virtqueue *_vq)
> +{
> + struct vring_virtqueue *vq = to_vvq(_vq);
> + unsigned int i;
> + void *buf;
> +
> + START_USE(vq);
> +
> + for (i = 0; i < vq->vring.num; i++) {
> + if (!vq->desc_state[i].data)
> + continue;
> + /* detach_buf clears data, so grab it now. */
> + buf = vq->desc_state[i].data;
> + detach_buf_split(vq, i, NULL);
> + vq->avail_idx_shadow--;
> + vq->vring.avail->idx = cpu_to_virtio16(_vq->vdev, vq->avail_idx_shadow);
> + END_USE(vq);
> + return buf;
> + }
> + /* That should have freed everything. */
> + BUG_ON(vq->vq.num_free != vq->vring.num);
> +
> + END_USE(vq);
> + return NULL;
> +}
> +
> +static void *virtqueue_detach_unused_buf_packed(struct virtqueue *_vq)
> +{
> + struct vring_virtqueue *vq = to_vvq(_vq);
> + unsigned int i, num;
> + void *buf;
> +
> + START_USE(vq);
> +
> + for (i = 0; i < vq->vring_packed.num; i++) {
> + if (!vq->desc_state[i].data)
> + continue;
> + /* detach_buf clears data, so grab it now. */
> + buf = vq->desc_state[i].data;
> + num = detach_buf_packed(vq, i, NULL);
> + if (vq->next_avail_idx < num) {
> + vq->next_avail_idx = vq->vring_packed.num -
> + (num - vq->next_avail_idx);
> + vq->wrap_counter ^= 1;
> + } else {
> + vq->next_avail_idx -= num;
> + }
> + END_USE(vq);
> + return buf;
> + }
> + /* That should have freed everything. */
> + BUG_ON(vq->vq.num_free != vq->vring_packed.num);
> +
> + END_USE(vq);
> + return NULL;
> +}
> +
> /**
> * virtqueue_detach_unused_buf - detach first unused buffer
> * @vq: the struct virtqueue we're talking about.
> @@ -910,27 +1569,9 @@ EXPORT_SYMBOL_GPL(virtqueue_enable_cb_delayed);
> void *virtqueue_detach_unused_buf(struct virtqueue *_vq)
> {
> struct vring_virtqueue *vq = to_vvq(_vq);
> - unsigned int i;
> - void *buf;
>
> - START_USE(vq);
> -
> - for (i = 0; i < vq->vring.num; i++) {
> - if (!vq->desc_state[i].data)
> - continue;
> - /* detach_buf clears data, so grab it now. */
> - buf = vq->desc_state[i].data;
> - detach_buf(vq, i, NULL);
> - vq->avail_idx_shadow--;
> - vq->vring.avail->idx = cpu_to_virtio16(_vq->vdev, vq->avail_idx_shadow);
> - END_USE(vq);
> - return buf;
> - }
> - /* That should have freed everything. */
> - BUG_ON(vq->vq.num_free != vq->vring.num);
> -
> - END_USE(vq);
> - return NULL;
> + return vq->packed ? virtqueue_detach_unused_buf_packed(_vq) :
> + virtqueue_detach_unused_buf_split(_vq);
> }
> EXPORT_SYMBOL_GPL(virtqueue_detach_unused_buf);
>
> @@ -955,7 +1596,8 @@ irqreturn_t vring_interrupt(int irq, void *_vq)
> EXPORT_SYMBOL_GPL(vring_interrupt);
>
> struct virtqueue *__vring_new_virtqueue(unsigned int index,
> - struct vring vring,
> + union vring_union vring,
> + bool packed,
> struct virtio_device *vdev,
> bool weak_barriers,
> bool context,
> @@ -963,19 +1605,20 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index,
> void (*callback)(struct virtqueue *),
> const char *name)
> {
> - unsigned int i;
> + unsigned int num, i;
> struct vring_virtqueue *vq;
>
> - vq = kmalloc(sizeof(*vq) + vring.num * sizeof(struct vring_desc_state),
> + num = packed ? vring.vring_packed.num : vring.vring_split.num;
> +
> + vq = kmalloc(sizeof(*vq) + num * sizeof(struct vring_desc_state),
> GFP_KERNEL);
> if (!vq)
> return NULL;
>
> - vq->vring = vring;
> vq->vq.callback = callback;
> vq->vq.vdev = vdev;
> vq->vq.name = name;
> - vq->vq.num_free = vring.num;
> + vq->vq.num_free = num;
> vq->vq.index = index;
> vq->we_own_ring = false;
> vq->queue_dma_addr = 0;
> @@ -984,9 +1627,8 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index,
> vq->weak_barriers = weak_barriers;
> vq->broken = false;
> vq->last_used_idx = 0;
> - vq->avail_flags_shadow = 0;
> - vq->avail_idx_shadow = 0;
> vq->num_added = 0;
> + vq->packed = packed;
> list_add_tail(&vq->vq.list, &vdev->vqs);
> #ifdef DEBUG
> vq->in_use = false;
> @@ -997,18 +1639,37 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index,
> !context;
> vq->event = virtio_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX);
>
> + if (vq->packed) {
> + vq->vring_packed = vring.vring_packed;
> + vq->next_avail_idx = 0;
> + vq->wrap_counter = 1;
> + vq->event_flags_shadow = 0;
> + } else {
> + vq->vring = vring.vring_split;
> + vq->avail_flags_shadow = 0;
> + vq->avail_idx_shadow = 0;
> +
> + /* Put everything in free lists. */
> + vq->free_head = 0;
> + for (i = 0; i < num-1; i++)
> + vq->vring.desc[i].next = cpu_to_virtio16(vdev, i + 1);
> + }
> +
> /* No callback? Tell other side not to bother us. */
> if (!callback) {
> - vq->avail_flags_shadow |= VRING_AVAIL_F_NO_INTERRUPT;
> - if (!vq->event)
> - vq->vring.avail->flags = cpu_to_virtio16(vdev, vq->avail_flags_shadow);
> + if (packed) {
> + vq->event_flags_shadow = VRING_EVENT_F_DISABLE;
> + vq->vring_packed.driver->flags = cpu_to_virtio16(vdev,
> + vq->event_flags_shadow);
> + } else {
> + vq->avail_flags_shadow |= VRING_AVAIL_F_NO_INTERRUPT;
> + if (!vq->event)
> + vq->vring.avail->flags = cpu_to_virtio16(vdev,
> + vq->avail_flags_shadow);
> + }
> }
>
> - /* Put everything in free lists. */
> - vq->free_head = 0;
> - for (i = 0; i < vring.num-1; i++)
> - vq->vring.desc[i].next = cpu_to_virtio16(vdev, i + 1);
> - memset(vq->desc_state, 0, vring.num * sizeof(struct vring_desc_state));
> + memset(vq->desc_state, 0, num * sizeof(struct vring_desc_state));
>
> return &vq->vq;
> }
> @@ -1056,6 +1717,22 @@ static void vring_free_queue(struct virtio_device *vdev, size_t size,
> }
> }
>
> +static inline int
> +__vring_size(unsigned int num, unsigned long align, bool packed)
> +{
> + return packed ? vring_packed_size(num, align) : vring_size(num, align);
> +}
> +
> +static inline void vring_packed_init(struct vring_packed *vr, unsigned int num,
> + void *p, unsigned long align)
> +{
> + vr->num = num;
> + vr->desc = p;
> + vr->driver = (void *)(((uintptr_t)p + sizeof(struct vring_packed_desc)
> + * num + align - 1) & ~(align - 1));
> + vr->device = vr->driver + 1;
> +}
> +
> struct virtqueue *vring_create_virtqueue(
> unsigned int index,
> unsigned int num,
> @@ -1072,7 +1749,8 @@ struct virtqueue *vring_create_virtqueue(
> void *queue = NULL;
> dma_addr_t dma_addr;
> size_t queue_size_in_bytes;
> - struct vring vring;
> + union vring_union vring;
> + bool packed;
>
> /* We assume num is a power of 2. */
> if (num & (num - 1)) {
> @@ -1080,9 +1758,13 @@ struct virtqueue *vring_create_virtqueue(
> return NULL;
> }
>
> + packed = virtio_has_feature(vdev, VIRTIO_F_RING_PACKED);
> +
> /* TODO: allocate each queue chunk individually */
> - for (; num && vring_size(num, vring_align) > PAGE_SIZE; num /= 2) {
> - queue = vring_alloc_queue(vdev, vring_size(num, vring_align),
> + for (; num && __vring_size(num, vring_align, packed) > PAGE_SIZE;
> + num /= 2) {
> + queue = vring_alloc_queue(vdev, __vring_size(num, vring_align,
> + packed),
> &dma_addr,
> GFP_KERNEL|__GFP_NOWARN|__GFP_ZERO);
> if (queue)
> @@ -1094,17 +1776,21 @@ struct virtqueue *vring_create_virtqueue(
>
> if (!queue) {
> /* Try to get a single page. You are my only hope! */
> - queue = vring_alloc_queue(vdev, vring_size(num, vring_align),
> + queue = vring_alloc_queue(vdev, __vring_size(num, vring_align,
> + packed),
> &dma_addr, GFP_KERNEL|__GFP_ZERO);
> }
> if (!queue)
> return NULL;
>
> - queue_size_in_bytes = vring_size(num, vring_align);
> - vring_init(&vring, num, queue, vring_align);
> + queue_size_in_bytes = __vring_size(num, vring_align, packed);
> + if (packed)
> + vring_packed_init(&vring.vring_packed, num, queue, vring_align);
> + else
> + vring_init(&vring.vring_split, num, queue, vring_align);
>
> - vq = __vring_new_virtqueue(index, vring, vdev, weak_barriers, context,
> - notify, callback, name);
> + vq = __vring_new_virtqueue(index, vring, packed, vdev, weak_barriers,
> + context, notify, callback, name);
> if (!vq) {
> vring_free_queue(vdev, queue_size_in_bytes, queue,
> dma_addr);
> @@ -1130,10 +1816,17 @@ struct virtqueue *vring_new_virtqueue(unsigned int index,
> void (*callback)(struct virtqueue *vq),
> const char *name)
> {
> - struct vring vring;
> - vring_init(&vring, num, pages, vring_align);
> - return __vring_new_virtqueue(index, vring, vdev, weak_barriers, context,
> - notify, callback, name);
> + union vring_union vring;
> + bool packed;
> +
> + packed = virtio_has_feature(vdev, VIRTIO_F_RING_PACKED);
> + if (packed)
> + vring_packed_init(&vring.vring_packed, num, pages, vring_align);
> + else
> + vring_init(&vring.vring_split, num, pages, vring_align);
> +
> + return __vring_new_virtqueue(index, vring, packed, vdev, weak_barriers,
> + context, notify, callback, name);
> }
> EXPORT_SYMBOL_GPL(vring_new_virtqueue);
>
> @@ -1143,7 +1836,9 @@ void vring_del_virtqueue(struct virtqueue *_vq)
>
> if (vq->we_own_ring) {
> vring_free_queue(vq->vq.vdev, vq->queue_size_in_bytes,
> - vq->vring.desc, vq->queue_dma_addr);
> + vq->packed ? (void *)vq->vring_packed.desc :
> + (void *)vq->vring.desc,
> + vq->queue_dma_addr);
> }
> list_del(&_vq->list);
> kfree(vq);
> @@ -1157,14 +1852,18 @@ void vring_transport_features(struct virtio_device *vdev)
>
> for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++) {
> switch (i) {
> - case VIRTIO_RING_F_INDIRECT_DESC:
> +#if 0
> + case VIRTIO_RING_F_INDIRECT_DESC: // FIXME not tested yet.
> break;
> - case VIRTIO_RING_F_EVENT_IDX:
> + case VIRTIO_RING_F_EVENT_IDX: // FIXME probably not work.
> break;
> +#endif
> case VIRTIO_F_VERSION_1:
> break;
> case VIRTIO_F_IOMMU_PLATFORM:
> break;
> + case VIRTIO_F_RING_PACKED:
> + break;
> default:
> /* We don't understand this bit. */
> __virtio_clear_bit(vdev, i);
> @@ -1185,7 +1884,7 @@ unsigned int virtqueue_get_vring_size(struct virtqueue *_vq)
>
> struct vring_virtqueue *vq = to_vvq(_vq);
>
> - return vq->vring.num;
> + return vq->packed ? vq->vring_packed.num : vq->vring.num;
> }
> EXPORT_SYMBOL_GPL(virtqueue_get_vring_size);
>
> @@ -1228,6 +1927,10 @@ dma_addr_t virtqueue_get_avail_addr(struct virtqueue *_vq)
>
> BUG_ON(!vq->we_own_ring);
>
> + if (vq->packed)
> + return vq->queue_dma_addr + ((char *)vq->vring_packed.driver -
> + (char *)vq->vring_packed.desc);
> +
> return vq->queue_dma_addr +
> ((char *)vq->vring.avail - (char *)vq->vring.desc);
> }
> @@ -1239,11 +1942,16 @@ dma_addr_t virtqueue_get_used_addr(struct virtqueue *_vq)
>
> BUG_ON(!vq->we_own_ring);
>
> + if (vq->packed)
> + return vq->queue_dma_addr + ((char *)vq->vring_packed.device -
> + (char *)vq->vring_packed.desc);
> +
> return vq->queue_dma_addr +
> ((char *)vq->vring.used - (char *)vq->vring.desc);
> }
> EXPORT_SYMBOL_GPL(virtqueue_get_used_addr);
>
> +/* Only available for split ring */
> const struct vring *virtqueue_get_vring(struct virtqueue *vq)
> {
> return &to_vvq(vq)->vring;
> diff --git a/include/linux/virtio_ring.h b/include/linux/virtio_ring.h
> index bbf32524ab27..a0075894ad16 100644
> --- a/include/linux/virtio_ring.h
> +++ b/include/linux/virtio_ring.h
> @@ -60,6 +60,11 @@ static inline void virtio_store_mb(bool weak_barriers,
> struct virtio_device;
> struct virtqueue;
>
> +union vring_union {
> + struct vring vring_split;
> + struct vring_packed vring_packed;
> +};
> +
> /*
> * Creates a virtqueue and allocates the descriptor ring. If
> * may_reduce_num is set, then this may allocate a smaller ring than
> @@ -79,7 +84,8 @@ struct virtqueue *vring_create_virtqueue(unsigned int index,
>
> /* Creates a virtqueue with a custom layout. */
> struct virtqueue *__vring_new_virtqueue(unsigned int index,
> - struct vring vring,
> + union vring_union vring,
> + bool packed,
> struct virtio_device *vdev,
> bool weak_barriers,
> bool ctx,
> diff --git a/include/uapi/linux/virtio_config.h b/include/uapi/linux/virtio_config.h
> index 308e2096291f..a6e392325e3a 100644
> --- a/include/uapi/linux/virtio_config.h
> +++ b/include/uapi/linux/virtio_config.h
> @@ -49,7 +49,7 @@
> * transport being used (eg. virtio_ring), the rest are per-device feature
> * bits. */
> #define VIRTIO_TRANSPORT_F_START 28
> -#define VIRTIO_TRANSPORT_F_END 34
> +#define VIRTIO_TRANSPORT_F_END 36
>
> #ifndef VIRTIO_CONFIG_NO_LEGACY
> /* Do we get callbacks when the ring is completely used, even if we've
> @@ -71,4 +71,14 @@
> * this is for compatibility with legacy systems.
> */
> #define VIRTIO_F_IOMMU_PLATFORM 33
> +
> +/* This feature indicates support for the packed virtqueue layout. */
> +#define VIRTIO_F_RING_PACKED 34
> +
> +/*
> + * This feature indicates that all buffers are used by the device
> + * in the same order in which they have been made available.
> + */
> +#define VIRTIO_F_IN_ORDER 35
> +
> #endif /* _UAPI_LINUX_VIRTIO_CONFIG_H */
> diff --git a/include/uapi/linux/virtio_ring.h b/include/uapi/linux/virtio_ring.h
> index 6d5d5faa989b..735d4207c988 100644
> --- a/include/uapi/linux/virtio_ring.h
> +++ b/include/uapi/linux/virtio_ring.h
> @@ -44,6 +44,9 @@
> /* This means the buffer contains a list of buffer descriptors. */
> #define VRING_DESC_F_INDIRECT 4
>
> +#define VRING_DESC_F_AVAIL(b) ((b) << 7)
> +#define VRING_DESC_F_USED(b) ((b) << 15)
> +
> /* The Host uses this in used->flags to advise the Guest: don't kick me when
> * you add a buffer. It's unreliable, so it's simply an optimization. Guest
> * will still kick if it's out of buffers. */
> @@ -53,6 +56,10 @@
> * optimization. */
> #define VRING_AVAIL_F_NO_INTERRUPT 1
>
> +#define VRING_EVENT_F_ENABLE 0x0
> +#define VRING_EVENT_F_DISABLE 0x1
> +#define VRING_EVENT_F_DESC 0x2
> +
> /* We support indirect buffer descriptors */
> #define VIRTIO_RING_F_INDIRECT_DESC 28
>
> @@ -171,4 +178,58 @@ static inline int vring_need_event(__u16 event_idx, __u16 new_idx, __u16 old)
> return (__u16)(new_idx - event_idx - 1) < (__u16)(new_idx - old);
> }
>
> +struct vring_packed_desc_event {
> + /* __virtio16 off : 15; // Descriptor Event Offset
> + * __virtio16 wrap : 1; // Descriptor Event Wrap Counter */
> + __virtio16 off_wrap;
> + /* __virtio16 flags : 2; // Descriptor Event Flags */
> + __virtio16 flags;
> +};
> +
> +struct vring_packed_desc {
> + /* Buffer Address. */
> + __virtio64 addr;
> + /* Buffer Length. */
> + __virtio32 len;
> + /* Buffer ID. */
> + __virtio16 id;
> + /* The flags depending on descriptor type. */
> + __virtio16 flags;
> +};
> +
> +struct vring_packed {
> + unsigned int num;
> +
> + struct vring_packed_desc *desc;
> +
> + struct vring_packed_desc_event *driver;
> +
> + struct vring_packed_desc_event *device;
> +};
> +
> +/* The standard layout for the packed ring is a continuous chunk of memory
> + * which looks like this.
> + *
> + * struct vring_packed
> + * {
> + * // The actual descriptors (16 bytes each)
> + * struct vring_packed_desc desc[num];
> + *
> + * // Padding to the next align boundary.
> + * char pad[];
> + *
> + * // Driver Event Suppression
> + * struct vring_packed_desc_event driver;
> + *
> + * // Device Event Suppression
> + * struct vring_packed_desc_event device;
> + * };
> + */
> +
> +static inline unsigned vring_packed_size(unsigned int num, unsigned long align)
> +{
> + return ((sizeof(struct vring_packed_desc) * num + align - 1)
> + & ~(align - 1)) + sizeof(struct vring_packed_desc_event) * 2;
> +}
> +
> #endif /* _UAPI_LINUX_VIRTIO_RING_H */
^ permalink raw reply
* Re: [RFC] vhost: introduce mdev based hardware vhost backend
From: Jason Wang @ 2018-04-10 2:52 UTC (permalink / raw)
To: Tiwei Bie, mst, alex.williamson, ddutile, alexander.h.duyck
Cc: virtio-dev, linux-kernel, kvm, virtualization, netdev, dan.daly,
cunming.liang, zhihong.wang, jianfeng.tan, xiao.w.wang
In-Reply-To: <20180402152330.4158-1-tiwei.bie@intel.com>
On 2018年04月02日 23:23, Tiwei Bie wrote:
> This patch introduces a mdev (mediated device) based hardware
> vhost backend. This backend is an abstraction of the various
> hardware vhost accelerators (potentially any device that uses
> virtio ring can be used as a vhost accelerator). Some generic
> mdev parent ops are provided for accelerator drivers to support
> generating mdev instances.
>
> What's this
> ===========
>
> The idea is that we can setup a virtio ring compatible device
> with the messages available at the vhost-backend. Originally,
> these messages are used to implement a software vhost backend,
> but now we will use these messages to setup a virtio ring
> compatible hardware device. Then the hardware device will be
> able to work with the guest virtio driver in the VM just like
> what the software backend does. That is to say, we can implement
> a hardware based vhost backend in QEMU, and any virtio ring
> compatible devices potentially can be used with this backend.
> (We also call it vDPA -- vhost Data Path Acceleration).
>
> One problem is that, different virtio ring compatible devices
> may have different device interfaces. That is to say, we will
> need different drivers in QEMU. It could be troublesome. And
> that's what this patch trying to fix. The idea behind this
> patch is very simple: mdev is a standard way to emulate device
> in kernel.
So you just move the abstraction layer from qemu to kernel, and you
still need different drivers in kernel for different device interfaces
of accelerators. This looks even more complex than leaving it in qemu.
As you said, another idea is to implement userspace vhost backend for
accelerators which seems easier and could co-work with other parts of
qemu without inventing new type of messages.
Need careful thought here to seek a best solution here.
> So we defined a standard device based on mdev, which
> is able to accept vhost messages. When the mdev emulation code
> (i.e. the generic mdev parent ops provided by this patch) gets
> vhost messages, it will parse and deliver them to accelerator
> drivers. Drivers can use these messages to setup accelerators.
>
> That is to say, the generic mdev parent ops (e.g. read()/write()/
> ioctl()/...) will be provided for accelerator drivers to register
> accelerators as mdev parent devices. And each accelerator device
> will support generating standard mdev instance(s).
>
> With this standard device interface, we will be able to just
> develop one userspace driver to implement the hardware based
> vhost backend in QEMU.
>
> Difference between vDPA and PCI passthru
> ========================================
>
> The key difference between vDPA and PCI passthru is that, in
> vDPA only the data path of the device (e.g. DMA ring, notify
> region and queue interrupt) is pass-throughed to the VM, the
> device control path (e.g. PCI configuration space and MMIO
> regions) is still defined and emulated by QEMU.
>
> The benefits of keeping virtio device emulation in QEMU compared
> with virtio device PCI passthru include (but not limit to):
>
> - consistent device interface for guest OS in the VM;
> - max flexibility on the hardware design, especially the
> accelerator for each vhost backend doesn't have to be a
> full PCI device;
> - leveraging the existing virtio live-migration framework;
>
> The interface of this mdev based device
> =======================================
>
> 1. BAR0
>
> The MMIO region described by BAR0 is the main control
> interface. Messages will be written to or read from
> this region.
>
> The message type is determined by the `request` field
> in message header. The message size is encoded in the
> message header too. The message format looks like this:
>
> struct vhost_vfio_op {
> __u64 request;
> __u32 flags;
> /* Flag values: */
> #define VHOST_VFIO_NEED_REPLY 0x1 /* Whether need reply */
> __u32 size;
> union {
> __u64 u64;
> struct vhost_vring_state state;
> struct vhost_vring_addr addr;
> struct vhost_memory memory;
> } payload;
> };
>
> The existing vhost-kernel ioctl cmds are reused as
> the message requests in above structure.
>
> Each message will be written to or read from this
> region at offset 0:
>
> int vhost_vfio_write(struct vhost_dev *dev, struct vhost_vfio_op *op)
> {
> int count = VHOST_VFIO_OP_HDR_SIZE + op->size;
> struct vhost_vfio *vfio = dev->opaque;
> int ret;
>
> ret = pwrite64(vfio->device_fd, op, count, vfio->bar0_offset);
> if (ret != count)
> return -1;
>
> return 0;
> }
>
> int vhost_vfio_read(struct vhost_dev *dev, struct vhost_vfio_op *op)
> {
> int count = VHOST_VFIO_OP_HDR_SIZE + op->size;
> struct vhost_vfio *vfio = dev->opaque;
> uint64_t request = op->request;
> int ret;
>
> ret = pread64(vfio->device_fd, op, count, vfio->bar0_offset);
> if (ret != count || request != op->request)
> return -1;
>
> return 0;
> }
>
> It's quite straightforward to set things to the device.
> Just need to write the message to device directly:
>
> int vhost_vfio_set_features(struct vhost_dev *dev, uint64_t features)
> {
> struct vhost_vfio_op op;
>
> op.request = VHOST_SET_FEATURES;
> op.flags = 0;
> op.size = sizeof(features);
> op.payload.u64 = features;
>
> return vhost_vfio_write(dev, &op);
> }
>
> To get things from the device, two steps are needed.
> Take VHOST_GET_FEATURE as an example:
>
> int vhost_vfio_get_features(struct vhost_dev *dev, uint64_t *features)
> {
> struct vhost_vfio_op op;
> int ret;
>
> op.request = VHOST_GET_FEATURES;
> op.flags = VHOST_VFIO_NEED_REPLY;
> op.size = 0;
>
> /* Just need to write the header */
> ret = vhost_vfio_write(dev, &op);
> if (ret != 0)
> goto out;
>
> /* `op` wasn't changed during write */
> op.flags = 0;
> op.size = sizeof(*features);
>
> ret = vhost_vfio_read(dev, &op);
> if (ret != 0)
> goto out;
>
> *features = op.payload.u64;
> out:
> return ret;
> }
>
> 2. BAR1 (mmap-able)
>
> The MMIO region described by BAR1 will be used to notify the
> device.
>
> Each queue will has a page for notification, and it can be
> mapped to VM (if hardware also supports), and the virtio
> driver in the VM will be able to notify the device directly.
>
> The MMIO region described by BAR1 is also write-able. If the
> accelerator's notification register(s) cannot be mapped to the
> VM, write() can also be used to notify the device. Something
> like this:
>
> void notify_relay(void *opaque)
> {
> ......
> offset = 0x1000 * queue_idx; /* XXX assume page size is 4K here. */
>
> ret = pwrite64(vfio->device_fd, &queue_idx, sizeof(queue_idx),
> vfio->bar1_offset + offset);
> ......
> }
>
> Other BARs are reserved.
>
> 3. VFIO interrupt ioctl API
>
> VFIO interrupt ioctl API is used to setup device interrupts.
> IRQ-bypass will also be supported.
>
> Currently, only VFIO_PCI_MSIX_IRQ_INDEX is supported.
>
> The API for drivers to provide mdev instances
> =============================================
>
> The read()/write()/ioctl()/mmap()/open()/release() mdev
> parent ops have been provided for accelerators' drivers
> to provide mdev instances.
>
> ssize_t vdpa_read(struct mdev_device *mdev, char __user *buf,
> size_t count, loff_t *ppos);
> ssize_t vdpa_write(struct mdev_device *mdev, const char __user *buf,
> size_t count, loff_t *ppos);
> long vdpa_ioctl(struct mdev_device *mdev, unsigned int cmd, unsigned long arg);
> int vdpa_mmap(struct mdev_device *mdev, struct vm_area_struct *vma);
> int vdpa_open(struct mdev_device *mdev);
> void vdpa_close(struct mdev_device *mdev);
>
> Each accelerator driver just needs to implement its own
> create()/remove() ops, and provide a vdpa device ops
> which will be called by the generic mdev emulation code.
>
> Currently, the vdpa device ops are defined as:
>
> typedef int (*vdpa_start_device_t)(struct vdpa_dev *vdpa);
> typedef int (*vdpa_stop_device_t)(struct vdpa_dev *vdpa);
> typedef int (*vdpa_dma_map_t)(struct vdpa_dev *vdpa);
> typedef int (*vdpa_dma_unmap_t)(struct vdpa_dev *vdpa);
> typedef int (*vdpa_set_eventfd_t)(struct vdpa_dev *vdpa, int vector, int fd);
> typedef u64 (*vdpa_supported_features_t)(struct vdpa_dev *vdpa);
> typedef void (*vdpa_notify_device_t)(struct vdpa_dev *vdpa, int qid);
> typedef u64 (*vdpa_get_notify_addr_t)(struct vdpa_dev *vdpa, int qid);
>
> struct vdpa_device_ops {
> vdpa_start_device_t start;
> vdpa_stop_device_t stop;
> vdpa_dma_map_t dma_map;
> vdpa_dma_unmap_t dma_unmap;
> vdpa_set_eventfd_t set_eventfd;
> vdpa_supported_features_t supported_features;
> vdpa_notify_device_t notify;
> vdpa_get_notify_addr_t get_notify_addr;
> };
>
> struct vdpa_dev {
> struct mdev_device *mdev;
> struct mutex ops_lock;
> u8 vconfig[VDPA_CONFIG_SIZE];
> int nr_vring;
> u64 features;
> u64 state;
> struct vhost_memory *mem_table;
> bool pending_reply;
> struct vhost_vfio_op pending;
> const struct vdpa_device_ops *ops;
> void *private;
> int max_vrings;
> struct vdpa_vring_info vring_info[0];
> };
>
> struct vdpa_dev *vdpa_alloc(struct mdev_device *mdev, void *private,
> int max_vrings);
> void vdpa_free(struct vdpa_dev *vdpa);
>
> A simple example
> ================
>
> # Query the number of available mdev instances
> $ cat /sys/class/mdev_bus/0000:06:00.2/mdev_supported_types/ifcvf_vdpa-vdpa_virtio/available_instances
>
> # Create a mdev instance
> $ echo $UUID > /sys/class/mdev_bus/0000:06:00.2/mdev_supported_types/ifcvf_vdpa-vdpa_virtio/create
>
> # Launch QEMU with a virtio-net device
> $ qemu \
> ...... \
> -netdev type=vhost-vfio,sysfsdev=/sys/bus/mdev/devices/$UUID,id=$ID \
> -device virtio-net-pci,netdev=$ID
>
> -------- END --------
>
> Most of above words will be refined and moved to a doc in
> the formal patch. In this RFC, all introductions and code
> are gathered in this patch, the idea is to make it easier
> to find all the relevant information. Anyone who wants to
> comment could use inline comment and just keep the relevant
> parts. Sorry for the big RFC patch..
>
> This patch is just a RFC for now, and something is still
> missing or needs to be refined. But it's never too early
> to hear the thoughts from the community. So any comments
> would be appreciated! Thanks! :-)
I don't see vhost_vfio_write() and other above functions in the patch.
Looks like some part of the patch is missed, it would be better to post
a complete series with an example driver (vDPA) to get a full picture.
Thanks
> Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
> ---
> drivers/vhost/Makefile | 3 +
> drivers/vhost/vdpa.c | 805 +++++++++++++++++++++++++++++++++++++++++++++
> include/linux/vdpa_mdev.h | 76 +++++
> include/uapi/linux/vhost.h | 26 ++
> 4 files changed, 910 insertions(+)
> create mode 100644 drivers/vhost/vdpa.c
> create mode 100644 include/linux/vdpa_mdev.h
>
> diff --git a/drivers/vhost/Makefile b/drivers/vhost/Makefile
> index 6c6df24f770c..7d185e083140 100644
> --- a/drivers/vhost/Makefile
> +++ b/drivers/vhost/Makefile
> @@ -11,3 +11,6 @@ vhost_vsock-y := vsock.o
> obj-$(CONFIG_VHOST_RING) += vringh.o
>
> obj-$(CONFIG_VHOST) += vhost.o
> +
> +obj-m += vhost_vdpa.o # FIXME: add an option
> +vhost_vdpa-y := vdpa.o
> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> new file mode 100644
> index 000000000000..aa19c266ea19
> --- /dev/null
> +++ b/drivers/vhost/vdpa.c
> @@ -0,0 +1,805 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2018 Intel Corporation.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/vfio.h>
> +#include <linux/vhost.h>
> +#include <linux/mdev.h>
> +#include <linux/vdpa_mdev.h>
> +
> +#define VDPA_BAR0_SIZE 0x1000000 // TBD
> +
> +#define VDPA_VFIO_PCI_OFFSET_SHIFT 40
> +#define VDPA_VFIO_PCI_OFFSET_MASK \
> + ((1ULL << VDPA_VFIO_PCI_OFFSET_SHIFT) - 1)
> +#define VDPA_VFIO_PCI_OFFSET_TO_INDEX(offset) \
> + ((offset) >> VDPA_VFIO_PCI_OFFSET_SHIFT)
> +#define VDPA_VFIO_PCI_INDEX_TO_OFFSET(index) \
> + ((u64)(index) << VDPA_VFIO_PCI_OFFSET_SHIFT)
> +#define VDPA_VFIO_PCI_BAR_OFFSET(offset) \
> + ((offset) & VDPA_VFIO_PCI_OFFSET_MASK)
> +
> +#define STORE_LE16(addr, val) (*(u16 *)(addr) = cpu_to_le16(val))
> +#define STORE_LE32(addr, val) (*(u32 *)(addr) = cpu_to_le32(val))
> +
> +static void vdpa_create_config_space(struct vdpa_dev *vdpa)
> +{
> + /* PCI device ID / vendor ID */
> + STORE_LE32(&vdpa->vconfig[0x0], 0xffffffff); // FIXME TBD
> +
> + /* Programming interface class */
> + vdpa->vconfig[0x9] = 0x00;
> +
> + /* Sub class */
> + vdpa->vconfig[0xa] = 0x00;
> +
> + /* Base class */
> + vdpa->vconfig[0xb] = 0x02;
> +
> + // FIXME TBD
> +}
> +
> +struct vdpa_dev *vdpa_alloc(struct mdev_device *mdev, void *private,
> + int max_vrings)
> +{
> + struct vdpa_dev *vdpa;
> + size_t size;
> +
> + size = sizeof(struct vdpa_dev) + max_vrings *
> + sizeof(struct vdpa_vring_info);
> +
> + vdpa = kzalloc(size, GFP_KERNEL);
> + if (vdpa == NULL)
> + return NULL;
> +
> + mutex_init(&vdpa->ops_lock);
> +
> + vdpa->mdev = mdev;
> + vdpa->private = private;
> + vdpa->max_vrings = max_vrings;
> +
> + vdpa_create_config_space(vdpa);
> +
> + return vdpa;
> +}
> +EXPORT_SYMBOL(vdpa_alloc);
> +
> +void vdpa_free(struct vdpa_dev *vdpa)
> +{
> + struct mdev_device *mdev;
> +
> + mdev = vdpa->mdev;
> +
> + vdpa->ops->stop(vdpa);
> + vdpa->ops->dma_unmap(vdpa);
> +
> + mdev_set_drvdata(mdev, NULL);
> +
> + mutex_destroy(&vdpa->ops_lock);
> +
> + kfree(vdpa->mem_table);
> + kfree(vdpa);
> +}
> +EXPORT_SYMBOL(vdpa_free);
> +
> +static ssize_t vdpa_handle_pcicfg_read(struct mdev_device *mdev,
> + char __user *buf, size_t count, loff_t *ppos)
> +{
> + struct vdpa_dev *vdpa;
> + loff_t pos = *ppos;
> + loff_t offset;
> +
> + vdpa = mdev_get_drvdata(mdev);
> + if (!vdpa)
> + return -ENODEV;
> +
> + offset = VDPA_VFIO_PCI_BAR_OFFSET(pos);
> +
> + if (count + offset > VDPA_CONFIG_SIZE)
> + return -EINVAL;
> +
> + if (copy_to_user(buf, (vdpa->vconfig + offset), count))
> + return -EFAULT;
> +
> + return count;
> +}
> +
> +static ssize_t vdpa_handle_bar0_read(struct mdev_device *mdev,
> + char __user *buf, size_t count, loff_t *ppos)
> +{
> + struct vdpa_dev *vdpa;
> + struct vhost_vfio_op *op = NULL;
> + loff_t pos = *ppos;
> + loff_t offset;
> + int ret;
> +
> + vdpa = mdev_get_drvdata(mdev);
> + if (!vdpa) {
> + ret = -ENODEV;
> + goto out;
> + }
> +
> + offset = VDPA_VFIO_PCI_BAR_OFFSET(pos);
> + if (offset != 0) {
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + if (!vdpa->pending_reply) {
> + ret = 0;
> + goto out;
> + }
> +
> + vdpa->pending_reply = false;
> +
> + op = kzalloc(VHOST_VFIO_OP_HDR_SIZE + VHOST_VFIO_OP_PAYLOAD_MAX_SIZE,
> + GFP_KERNEL);
> + if (op == NULL) {
> + ret = -ENOMEM;
> + goto out;
> + }
> +
> + op->request = vdpa->pending.request;
> +
> + switch (op->request) {
> + case VHOST_GET_VRING_BASE:
> + op->payload.state = vdpa->pending.payload.state;
> + op->size = sizeof(op->payload.state);
> + break;
> + case VHOST_GET_FEATURES:
> + op->payload.u64 = vdpa->pending.payload.u64;
> + op->size = sizeof(op->payload.u64);
> + break;
> + default:
> + ret = -EINVAL;
> + goto out_free;
> + }
> +
> + if (op->size + VHOST_VFIO_OP_HDR_SIZE != count) {
> + ret = -EINVAL;
> + goto out_free;
> + }
> +
> + if (copy_to_user(buf, op, count)) {
> + ret = -EFAULT;
> + goto out_free;
> + }
> +
> + ret = count;
> +
> +out_free:
> + kfree(op);
> +out:
> + return ret;
> +}
> +
> +ssize_t vdpa_read(struct mdev_device *mdev, char __user *buf,
> + size_t count, loff_t *ppos)
> +{
> + int done = 0;
> + unsigned int index;
> + loff_t pos = *ppos;
> + struct vdpa_dev *vdpa;
> +
> + vdpa = mdev_get_drvdata(mdev);
> + if (!vdpa)
> + return -ENODEV;
> +
> + mutex_lock(&vdpa->ops_lock);
> +
> + index = VDPA_VFIO_PCI_OFFSET_TO_INDEX(pos);
> +
> + switch (index) {
> + case VFIO_PCI_CONFIG_REGION_INDEX:
> + done = vdpa_handle_pcicfg_read(mdev, buf, count, ppos);
> + break;
> + case VFIO_PCI_BAR0_REGION_INDEX:
> + done = vdpa_handle_bar0_read(mdev, buf, count, ppos);
> + break;
> + }
> +
> + if (done > 0)
> + *ppos += done;
> +
> + mutex_unlock(&vdpa->ops_lock);
> +
> + return done;
> +}
> +EXPORT_SYMBOL(vdpa_read);
> +
> +static ssize_t vdpa_handle_pcicfg_write(struct mdev_device *mdev,
> + const char __user *buf, size_t count, loff_t *ppos)
> +{
> + return count;
> +}
> +
> +static int vhost_set_mem_table(struct mdev_device *mdev,
> + struct vhost_memory *mem)
> +{
> + struct vdpa_dev *vdpa;
> + struct vhost_memory *mem_table;
> + size_t size;
> +
> + vdpa = mdev_get_drvdata(mdev);
> + if (!vdpa)
> + return -ENODEV;
> +
> + // FIXME fix this
> + if (vdpa->state != VHOST_DEVICE_S_STOPPED)
> + return -EBUSY;
> +
> + size = sizeof(*mem) + mem->nregions * sizeof(*mem->regions);
> +
> + mem_table = kzalloc(size, GFP_KERNEL);
> + if (mem_table == NULL)
> + return -ENOMEM;
> +
> + memcpy(mem_table, mem, size);
> +
> + kfree(vdpa->mem_table);
> +
> + vdpa->mem_table = mem_table;
> +
> + vdpa->ops->dma_unmap(vdpa);
> + vdpa->ops->dma_map(vdpa);
> +
> + return 0;
> +}
> +
> +static int vhost_set_vring_addr(struct mdev_device *mdev,
> + struct vhost_vring_addr *addr)
> +{
> + struct vdpa_dev *vdpa;
> + int qid = addr->index;
> + struct vdpa_vring_info *vring;
> +
> + vdpa = mdev_get_drvdata(mdev);
> + if (!vdpa)
> + return -ENODEV;
> +
> + if (qid >= vdpa->max_vrings)
> + return -EINVAL;
> +
> + /* FIXME to be fixed */
> + if (qid >= vdpa->nr_vring)
> + vdpa->nr_vring = qid + 1;
> +
> + vring = &vdpa->vring_info[qid];
> +
> + vring->desc_user_addr = addr->desc_user_addr;
> + vring->used_user_addr = addr->used_user_addr;
> + vring->avail_user_addr = addr->avail_user_addr;
> + vring->log_guest_addr = addr->log_guest_addr;
> +
> + return 0;
> +}
> +
> +static int vhost_set_vring_num(struct mdev_device *mdev,
> + struct vhost_vring_state *num)
> +{
> + struct vdpa_dev *vdpa;
> + int qid = num->index;
> + struct vdpa_vring_info *vring;
> +
> + vdpa = mdev_get_drvdata(mdev);
> + if (!vdpa)
> + return -ENODEV;
> +
> + if (qid >= vdpa->max_vrings)
> + return -EINVAL;
> +
> + vring = &vdpa->vring_info[qid];
> +
> + vring->size = num->num;
> +
> + return 0;
> +}
> +
> +static int vhost_set_vring_base(struct mdev_device *mdev,
> + struct vhost_vring_state *base)
> +{
> + struct vdpa_dev *vdpa;
> + int qid = base->index;
> + struct vdpa_vring_info *vring;
> +
> + vdpa = mdev_get_drvdata(mdev);
> + if (!vdpa)
> + return -ENODEV;
> +
> + if (qid >= vdpa->max_vrings)
> + return -EINVAL;
> +
> + vring = &vdpa->vring_info[qid];
> +
> + vring->base = base->num;
> +
> + return 0;
> +}
> +
> +static int vhost_get_vring_base(struct mdev_device *mdev,
> + struct vhost_vring_state *base)
> +{
> + struct vdpa_dev *vdpa;
> +
> + vdpa = mdev_get_drvdata(mdev);
> + if (!vdpa)
> + return -ENODEV;
> +
> + vdpa->pending_reply = true;
> + vdpa->pending.request = VHOST_GET_VRING_BASE;
> + vdpa->pending.payload.state.index = base->index;
> +
> + // FIXME to be implemented
> +
> + return 0;
> +}
> +
> +static int vhost_set_features(struct mdev_device *mdev, u64 *features)
> +{
> + struct vdpa_dev *vdpa;
> +
> + vdpa = mdev_get_drvdata(mdev);
> + if (!vdpa)
> + return -ENODEV;
> +
> + vdpa->features = *features;
> +
> + return 0;
> +}
> +
> +static int vhost_get_features(struct mdev_device *mdev, u64 *features)
> +{
> + struct vdpa_dev *vdpa;
> +
> + vdpa = mdev_get_drvdata(mdev);
> + if (!vdpa)
> + return -ENODEV;
> +
> + vdpa->pending_reply = true;
> + vdpa->pending.request = VHOST_GET_FEATURES;
> + vdpa->pending.payload.u64 =
> + vdpa->ops->supported_features(vdpa);
> +
> + return 0;
> +}
> +
> +static int vhost_set_owner(struct mdev_device *mdev)
> +{
> + return 0;
> +}
> +
> +static int vhost_reset_owner(struct mdev_device *mdev)
> +{
> + return 0;
> +}
> +
> +static int vhost_set_state(struct mdev_device *mdev, u64 *state)
> +{
> + struct vdpa_dev *vdpa;
> +
> + vdpa = mdev_get_drvdata(mdev);
> + if (!vdpa)
> + return -ENODEV;
> +
> + if (*state >= VHOST_DEVICE_S_MAX)
> + return -EINVAL;
> +
> + if (vdpa->state == *state)
> + return 0;
> +
> + vdpa->state = *state;
> +
> + switch (vdpa->state) {
> + case VHOST_DEVICE_S_RUNNING:
> + vdpa->ops->start(vdpa);
> + break;
> + case VHOST_DEVICE_S_STOPPED:
> + vdpa->ops->stop(vdpa);
> + break;
> + }
> +
> + return 0;
> +}
> +
> +static ssize_t vdpa_handle_bar0_write(struct mdev_device *mdev,
> + const char __user *buf, size_t count, loff_t *ppos)
> +{
> + struct vhost_vfio_op *op = NULL;
> + loff_t pos = *ppos;
> + loff_t offset;
> + int ret;
> +
> + offset = VDPA_VFIO_PCI_BAR_OFFSET(pos);
> + if (offset != 0) {
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + if (count < VHOST_VFIO_OP_HDR_SIZE) {
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + op = kzalloc(VHOST_VFIO_OP_HDR_SIZE + VHOST_VFIO_OP_PAYLOAD_MAX_SIZE,
> + GFP_KERNEL);
> + if (op == NULL) {
> + ret = -ENOMEM;
> + goto out;
> + }
> +
> + if (copy_from_user(op, buf, VHOST_VFIO_OP_HDR_SIZE)) {
> + ret = -EINVAL;
> + goto out_free;
> + }
> +
> + if (op->size > VHOST_VFIO_OP_PAYLOAD_MAX_SIZE ||
> + op->size + VHOST_VFIO_OP_HDR_SIZE != count) {
> + ret = -EINVAL;
> + goto out_free;
> + }
> +
> + if (copy_from_user(&op->payload, buf + VHOST_VFIO_OP_HDR_SIZE,
> + op->size)) {
> + ret = -EFAULT;
> + goto out_free;
> + }
> +
> + switch (op->request) {
> + case VHOST_SET_LOG_BASE:
> + break;
> + case VHOST_SET_MEM_TABLE:
> + vhost_set_mem_table(mdev, &op->payload.memory);
> + break;
> + case VHOST_SET_VRING_ADDR:
> + vhost_set_vring_addr(mdev, &op->payload.addr);
> + break;
> + case VHOST_SET_VRING_NUM:
> + vhost_set_vring_num(mdev, &op->payload.state);
> + break;
> + case VHOST_SET_VRING_BASE:
> + vhost_set_vring_base(mdev, &op->payload.state);
> + break;
> + case VHOST_GET_VRING_BASE:
> + vhost_get_vring_base(mdev, &op->payload.state);
> + break;
> + case VHOST_SET_FEATURES:
> + vhost_set_features(mdev, &op->payload.u64);
> + break;
> + case VHOST_GET_FEATURES:
> + vhost_get_features(mdev, &op->payload.u64);
> + break;
> + case VHOST_SET_OWNER:
> + vhost_set_owner(mdev);
> + break;
> + case VHOST_RESET_OWNER:
> + vhost_reset_owner(mdev);
> + break;
> + case VHOST_DEVICE_SET_STATE:
> + vhost_set_state(mdev, &op->payload.u64);
> + break;
> + default:
> + break;
> + }
> +
> + ret = count;
> +
> +out_free:
> + kfree(op);
> +out:
> + return ret;
> +}
> +
> +static ssize_t vdpa_handle_bar1_write(struct mdev_device *mdev,
> + const char __user *buf, size_t count, loff_t *ppos)
> +{
> + struct vdpa_dev *vdpa;
> + int qid;
> +
> + vdpa = mdev_get_drvdata(mdev);
> + if (!vdpa)
> + return -ENODEV;
> +
> + if (count < sizeof(qid))
> + return -EINVAL;
> +
> + if (copy_from_user(&qid, buf, sizeof(qid)))
> + return -EINVAL;
> +
> + vdpa->ops->notify(vdpa, qid);
> +
> + return count;
> +}
> +
> +ssize_t vdpa_write(struct mdev_device *mdev, const char __user *buf,
> + size_t count, loff_t *ppos)
> +{
> + int done = 0;
> + unsigned int index;
> + loff_t pos = *ppos;
> + struct vdpa_dev *vdpa;
> +
> + vdpa = mdev_get_drvdata(mdev);
> + if (!vdpa)
> + return -ENODEV;
> +
> + mutex_lock(&vdpa->ops_lock);
> +
> + index = VDPA_VFIO_PCI_OFFSET_TO_INDEX(pos);
> +
> + switch (index) {
> + case VFIO_PCI_CONFIG_REGION_INDEX:
> + done = vdpa_handle_pcicfg_write(mdev, buf, count, ppos);
> + break;
> + case VFIO_PCI_BAR0_REGION_INDEX:
> + done = vdpa_handle_bar0_write(mdev, buf, count, ppos);
> + break;
> + case VFIO_PCI_BAR1_REGION_INDEX:
> + done = vdpa_handle_bar1_write(mdev, buf, count, ppos);
> + break;
> + }
> +
> + if (done > 0)
> + *ppos += done;
> +
> + mutex_unlock(&vdpa->ops_lock);
> +
> + return done;
> +}
> +EXPORT_SYMBOL(vdpa_write);
> +
> +static int vdpa_get_region_info(struct mdev_device *mdev,
> + struct vfio_region_info *region_info,
> + u16 *cap_type_id, void **cap_type)
> +{
> + struct vdpa_dev *vdpa;
> + u32 bar_index;
> + u64 size = 0;
> +
> + if (!mdev)
> + return -EINVAL;
> +
> + vdpa = mdev_get_drvdata(mdev);
> + if (!vdpa)
> + return -EINVAL;
> +
> + bar_index = region_info->index;
> + if (bar_index >= VFIO_PCI_NUM_REGIONS)
> + return -EINVAL;
> +
> + mutex_lock(&vdpa->ops_lock);
> +
> + switch (bar_index) {
> + case VFIO_PCI_CONFIG_REGION_INDEX:
> + size = VDPA_CONFIG_SIZE;
> + break;
> + case VFIO_PCI_BAR0_REGION_INDEX:
> + size = VDPA_BAR0_SIZE;
> + break;
> + case VFIO_PCI_BAR1_REGION_INDEX:
> + size = (u64)vdpa->max_vrings << PAGE_SHIFT;
> + break;
> + default:
> + size = 0;
> + break;
> + }
> +
> + // FIXME: mark BAR1 as mmap-able (VFIO_REGION_INFO_FLAG_MMAP)
> + region_info->size = size;
> + region_info->offset = VDPA_VFIO_PCI_INDEX_TO_OFFSET(bar_index);
> + region_info->flags = VFIO_REGION_INFO_FLAG_READ |
> + VFIO_REGION_INFO_FLAG_WRITE;
> + mutex_unlock(&vdpa->ops_lock);
> + return 0;
> +}
> +
> +static int vdpa_reset(struct mdev_device *mdev)
> +{
> + struct vdpa_dev *vdpa;
> +
> + if (!mdev)
> + return -EINVAL;
> +
> + vdpa = mdev_get_drvdata(mdev);
> + if (!vdpa)
> + return -EINVAL;
> +
> + return 0;
> +}
> +
> +static int vdpa_get_device_info(struct mdev_device *mdev,
> + struct vfio_device_info *dev_info)
> +{
> + struct vdpa_dev *vdpa;
> +
> + vdpa = mdev_get_drvdata(mdev);
> + if (!vdpa)
> + return -ENODEV;
> +
> + dev_info->flags = VFIO_DEVICE_FLAGS_PCI;
> + dev_info->num_regions = VFIO_PCI_NUM_REGIONS;
> + dev_info->num_irqs = vdpa->max_vrings;
> +
> + return 0;
> +}
> +
> +static int vdpa_get_irq_info(struct mdev_device *mdev,
> + struct vfio_irq_info *info)
> +{
> + struct vdpa_dev *vdpa;
> +
> + vdpa = mdev_get_drvdata(mdev);
> + if (!vdpa)
> + return -ENODEV;
> +
> + if (info->index != VFIO_PCI_MSIX_IRQ_INDEX)
> + return -ENOTSUPP;
> +
> + info->flags = VFIO_IRQ_INFO_EVENTFD;
> + info->count = vdpa->max_vrings;
> +
> + return 0;
> +}
> +
> +static int vdpa_set_irqs(struct mdev_device *mdev, uint32_t flags,
> + unsigned int index, unsigned int start,
> + unsigned int count, void *data)
> +{
> + struct vdpa_dev *vdpa;
> + int *fd = data, i;
> +
> + vdpa = mdev_get_drvdata(mdev);
> + if (!vdpa)
> + return -EINVAL;
> +
> + if (index != VFIO_PCI_MSIX_IRQ_INDEX)
> + return -ENOTSUPP;
> +
> + for (i = 0; i < count; i++)
> + vdpa->ops->set_eventfd(vdpa, start + i,
> + (flags & VFIO_IRQ_SET_DATA_EVENTFD) ? fd[i] : -1);
> +
> + return 0;
> +}
> +
> +long vdpa_ioctl(struct mdev_device *mdev, unsigned int cmd, unsigned long arg)
> +{
> + int ret = 0;
> + unsigned long minsz;
> + struct vdpa_dev *vdpa;
> +
> + if (!mdev)
> + return -EINVAL;
> +
> + vdpa = mdev_get_drvdata(mdev);
> + if (!vdpa)
> + return -ENODEV;
> +
> + switch (cmd) {
> + case VFIO_DEVICE_GET_INFO:
> + {
> + struct vfio_device_info info;
> +
> + minsz = offsetofend(struct vfio_device_info, num_irqs);
> +
> + if (copy_from_user(&info, (void __user *)arg, minsz))
> + return -EFAULT;
> +
> + if (info.argsz < minsz)
> + return -EINVAL;
> +
> + ret = vdpa_get_device_info(mdev, &info);
> + if (ret)
> + return ret;
> +
> + if (copy_to_user((void __user *)arg, &info, minsz))
> + return -EFAULT;
> +
> + return 0;
> + }
> + case VFIO_DEVICE_GET_REGION_INFO:
> + {
> + struct vfio_region_info info;
> + u16 cap_type_id = 0;
> + void *cap_type = NULL;
> +
> + minsz = offsetofend(struct vfio_region_info, offset);
> +
> + if (copy_from_user(&info, (void __user *)arg, minsz))
> + return -EFAULT;
> +
> + if (info.argsz < minsz)
> + return -EINVAL;
> +
> + ret = vdpa_get_region_info(mdev, &info, &cap_type_id,
> + &cap_type);
> + if (ret)
> + return ret;
> +
> + if (copy_to_user((void __user *)arg, &info, minsz))
> + return -EFAULT;
> +
> + return 0;
> + }
> + case VFIO_DEVICE_GET_IRQ_INFO:
> + {
> + struct vfio_irq_info info;
> +
> + minsz = offsetofend(struct vfio_irq_info, count);
> +
> + if (copy_from_user(&info, (void __user *)arg, minsz))
> + return -EFAULT;
> +
> + if (info.argsz < minsz || info.index >= vdpa->max_vrings)
> + return -EINVAL;
> +
> + ret = vdpa_get_irq_info(mdev, &info);
> + if (ret)
> + return ret;
> +
> + if (copy_to_user((void __user *)arg, &info, minsz))
> + return -EFAULT;
> +
> + return 0;
> + }
> + case VFIO_DEVICE_SET_IRQS:
> + {
> + struct vfio_irq_set hdr;
> + size_t data_size = 0;
> + u8 *data = NULL;
> +
> + minsz = offsetofend(struct vfio_irq_set, count);
> +
> + if (copy_from_user(&hdr, (void __user *)arg, minsz))
> + return -EFAULT;
> +
> + ret = vfio_set_irqs_validate_and_prepare(&hdr, vdpa->max_vrings,
> + VFIO_PCI_NUM_IRQS,
> + &data_size);
> + if (ret)
> + return ret;
> +
> + if (data_size) {
> + data = memdup_user((void __user *)(arg + minsz),
> + data_size);
> + if (IS_ERR(data))
> + return PTR_ERR(data);
> + }
> +
> + ret = vdpa_set_irqs(mdev, hdr.flags, hdr.index, hdr.start,
> + hdr.count, data);
> +
> + kfree(data);
> + return ret;
> + }
> + case VFIO_DEVICE_RESET:
> + return vdpa_reset(mdev);
> + }
> + return -ENOTTY;
> +}
> +EXPORT_SYMBOL(vdpa_ioctl);
> +
> +int vdpa_mmap(struct mdev_device *mdev, struct vm_area_struct *vma)
> +{
> + // FIXME: to be implemented
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(vdpa_mmap);
> +
> +int vdpa_open(struct mdev_device *mdev)
> +{
> + return 0;
> +}
> +EXPORT_SYMBOL(vdpa_open);
> +
> +void vdpa_close(struct mdev_device *mdev)
> +{
> +}
> +EXPORT_SYMBOL(vdpa_close);
> +
> +MODULE_VERSION("0.0.0");
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("Hardware virtio accelerator abstraction");
> diff --git a/include/linux/vdpa_mdev.h b/include/linux/vdpa_mdev.h
> new file mode 100644
> index 000000000000..8414e86ba4b8
> --- /dev/null
> +++ b/include/linux/vdpa_mdev.h
> @@ -0,0 +1,76 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2018 Intel Corporation.
> + */
> +
> +#ifndef VDPA_MDEV_H
> +#define VDPA_MDEV_H
> +
> +#define VDPA_CONFIG_SIZE 0xff
> +
> +struct mdev_device;
> +struct vdpa_dev;
> +
> +/*
> + * XXX: Any comments about the vDPA API design for drivers
> + * would be appreciated!
> + */
> +
> +typedef int (*vdpa_start_device_t)(struct vdpa_dev *vdpa);
> +typedef int (*vdpa_stop_device_t)(struct vdpa_dev *vdpa);
> +typedef int (*vdpa_dma_map_t)(struct vdpa_dev *vdpa);
> +typedef int (*vdpa_dma_unmap_t)(struct vdpa_dev *vdpa);
> +typedef int (*vdpa_set_eventfd_t)(struct vdpa_dev *vdpa, int vector, int fd);
> +typedef u64 (*vdpa_supported_features_t)(struct vdpa_dev *vdpa);
> +typedef void (*vdpa_notify_device_t)(struct vdpa_dev *vdpa, int qid);
> +typedef u64 (*vdpa_get_notify_addr_t)(struct vdpa_dev *vdpa, int qid);
> +
> +struct vdpa_device_ops {
> + vdpa_start_device_t start;
> + vdpa_stop_device_t stop;
> + vdpa_dma_map_t dma_map;
> + vdpa_dma_unmap_t dma_unmap;
> + vdpa_set_eventfd_t set_eventfd;
> + vdpa_supported_features_t supported_features;
> + vdpa_notify_device_t notify;
> + vdpa_get_notify_addr_t get_notify_addr;
> +};
> +
> +struct vdpa_vring_info {
> + u64 desc_user_addr;
> + u64 used_user_addr;
> + u64 avail_user_addr;
> + u64 log_guest_addr;
> + u16 size;
> + u16 base;
> +};
> +
> +struct vdpa_dev {
> + struct mdev_device *mdev;
> + struct mutex ops_lock;
> + u8 vconfig[VDPA_CONFIG_SIZE];
> + int nr_vring;
> + u64 features;
> + u64 state;
> + struct vhost_memory *mem_table;
> + bool pending_reply;
> + struct vhost_vfio_op pending;
> + const struct vdpa_device_ops *ops;
> + void *private;
> + int max_vrings;
> + struct vdpa_vring_info vring_info[0];
> +};
> +
> +struct vdpa_dev *vdpa_alloc(struct mdev_device *mdev, void *private,
> + int max_vrings);
> +void vdpa_free(struct vdpa_dev *vdpa);
> +ssize_t vdpa_read(struct mdev_device *mdev, char __user *buf,
> + size_t count, loff_t *ppos);
> +ssize_t vdpa_write(struct mdev_device *mdev, const char __user *buf,
> + size_t count, loff_t *ppos);
> +long vdpa_ioctl(struct mdev_device *mdev, unsigned int cmd, unsigned long arg);
> +int vdpa_mmap(struct mdev_device *mdev, struct vm_area_struct *vma);
> +int vdpa_open(struct mdev_device *mdev);
> +void vdpa_close(struct mdev_device *mdev);
> +
> +#endif /* VDPA_MDEV_H */
> diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h
> index c51f8e5cc608..92a1ca0b5fe1 100644
> --- a/include/uapi/linux/vhost.h
> +++ b/include/uapi/linux/vhost.h
> @@ -207,4 +207,30 @@ struct vhost_scsi_target {
> #define VHOST_VSOCK_SET_GUEST_CID _IOW(VHOST_VIRTIO, 0x60, __u64)
> #define VHOST_VSOCK_SET_RUNNING _IOW(VHOST_VIRTIO, 0x61, int)
>
> +/* VHOST_DEVICE specific defines */
> +
> +#define VHOST_DEVICE_SET_STATE _IOW(VHOST_VIRTIO, 0x70, __u64)
> +
> +#define VHOST_DEVICE_S_STOPPED 0
> +#define VHOST_DEVICE_S_RUNNING 1
> +#define VHOST_DEVICE_S_MAX 2
> +
> +struct vhost_vfio_op {
> + __u64 request;
> + __u32 flags;
> + /* Flag values: */
> +#define VHOST_VFIO_NEED_REPLY 0x1 /* Whether need reply */
> + __u32 size;
> + union {
> + __u64 u64;
> + struct vhost_vring_state state;
> + struct vhost_vring_addr addr;
> + struct vhost_memory memory;
> + } payload;
> +};
> +
> +#define VHOST_VFIO_OP_HDR_SIZE \
> + ((unsigned long)&((struct vhost_vfio_op *)NULL)->payload)
> +#define VHOST_VFIO_OP_PAYLOAD_MAX_SIZE 1024 /* FIXME TBD */
> +
> #endif
^ permalink raw reply
* Re: [PATCH net 3/3] lan78xx: Lan7801 Support for Fixed PHY
From: Andrew Lunn @ 2018-04-10 2:49 UTC (permalink / raw)
To: RaghuramChary.Jallipalli; +Cc: davem, netdev, UNGLinuxDriver, Woojung.Huh
In-Reply-To: <0573C9D4B793EF43BF95221F2F4CC851533633@CHN-SV-EXMX06.mchp-main.com>
On Tue, Apr 10, 2018 at 02:23:23AM +0000, RaghuramChary.Jallipalli@microchip.com wrote:
> >
> > What do you expect is connected to the MAC if there is no PHY?
> >
> Hi Andrew,
> We connect the Ethernet switch to this MAC.
Ah, cool. I was thinking you were going to say an SFP cage.
What switch is it? Does it have a DSA driver?
Andrew
^ permalink raw reply
* Re: [PATCH 2/2] alx: add disable_wol paramenter
From: AceLan Kao @ 2018-04-10 2:40 UTC (permalink / raw)
To: David Miller
Cc: andrew, jcliburn, chris.snook, rakesh, netdev,
Linux-Kernel@Vger. Kernel. Org
In-Reply-To: <20180409.105039.310935818370762783.davem@davemloft.net>
The problem is I don't have a machine with that wakeup issue, and I
need WoL feature.
Instead of spreading "alx with WoL" dkms package everywhere, I would
like to see it's supported in the driver and is disabled by default.
Moreover, the wakeup issue may come from old Atheros chips, or result
from buggy BIOS.
With the WoL has been removed from the driver, no one will report
issue about that, and we don't have any chance to find a fix for it.
Adding this feature back is not covering a paper on the issue, it
makes people have a chance to examine this feature.
2018-04-09 22:50 GMT+08:00 David Miller <davem@davemloft.net>:
> From: Andrew Lunn <andrew@lunn.ch>
> Date: Mon, 9 Apr 2018 14:39:10 +0200
>
>> On Mon, Apr 09, 2018 at 07:35:14PM +0800, AceLan Kao wrote:
>>> The WoL feature was reported broken and will lead to
>>> the system resume immediately after suspending.
>>> This symptom is not happening on every system, so adding
>>> disable_wol option and disable WoL by default to prevent the issue from
>>> happening again.
>>
>>> const char alx_drv_name[] = "alx";
>>>
>>> +/* disable WoL by default */
>>> +bool disable_wol = 1;
>>> +module_param(disable_wol, bool, 0);
>>> +MODULE_PARM_DESC(disable_wol, "Disable Wake on Lan feature");
>>> +
>>
>> Hi AceLan
>>
>> This seems like you are papering over the cracks. And module
>> parameters are not liked.
>>
>> Please try to find the real problem.
>
> Agreed.
^ permalink raw reply
* RE: [PATCH net 1/3] lan78xx: PHY DSP registers initialization to address EEE link drop issues with long cables
From: RaghuramChary.Jallipalli @ 2018-04-10 2:27 UTC (permalink / raw)
To: davem, andrew; +Cc: netdev, UNGLinuxDriver, Woojung.Huh
In-Reply-To: <20180406.112158.2189892992551033169.davem@davemloft.net>
> >
> > Hi Raghuram
> >
> > You might want to look at phy_read_paged(), phy_write_paged(), etc.
> >
> > There can be race conditions with paged access.
>
> Yep, so something like:
>
> static void lan88xx_TR_reg_set(struct phy_device *phydev, u16 regaddr,
> u32 data)
> {
> int save_page, val;
> u16 buf;
>
> save_page = phy_save_page(phydev);
> phy_write_paged(phydev, LAN88XX_EXT_PAGE_ACCESS_TR,
> LAN88XX_EXT_PAGE_TR_LOW_DATA, (data &
> 0xFFFF));
> phy_write_paged(phydev, LAN88XX_EXT_PAGE_ACCESS_TR,
> LAN88XX_EXT_PAGE_TR_HIGH_DATA,
> (data & 0x00FF0000) >> 16);
>
> /* Config control bits [15:13] of register */
> buf = (regaddr & ~(0x3 << 13));/* Clr [14:13] to write data in reg */
> buf |= 0x8000; /* Set [15] to Packet transmit */
>
> phy_write_paged(phydev, LAN88XX_EXT_PAGE_ACCESS_TR,
> LAN88XX_EXT_PAGE_TR_CR, buf);
> usleep_range(1000, 2000);/* Wait for Data to be written */
>
> val = phy_read_paged(phydev, LAN88XX_EXT_PAGE_ACCESS_TR,
> LAN88XX_EXT_PAGE_TR_CR);
> if (!(val & 0x8000))
> pr_warn("TR Register[0x%X] configuration failed\n",
> regaddr);
>
> phy_restore_page(phydev, save_page, 0); }
>
> Since PHY accesses and thus things like phy_save_page() can fail, the return
> type of this function should be changed to 'int' and some error checking
> should be added.
Thanks David/Andrew.
Will take care of it.
Thanks,
Raghu
^ permalink raw reply
* RE: [PATCH net 2/3] lan78xx: Add support to dump lan78xx registers
From: RaghuramChary.Jallipalli @ 2018-04-10 2:25 UTC (permalink / raw)
To: andrew; +Cc: davem, netdev, UNGLinuxDriver, Woojung.Huh
In-Reply-To: <20180406144033.GM17495@lunn.ch>
> If there is no PHY attached, you probably should not include PHY_REG_SIZE
> here.
>
Sure, will address it.
Thanks,
Raghu
^ permalink raw reply
* RE: [PATCH net 3/3] lan78xx: Lan7801 Support for Fixed PHY
From: RaghuramChary.Jallipalli @ 2018-04-10 2:23 UTC (permalink / raw)
To: andrew; +Cc: davem, netdev, UNGLinuxDriver, Woojung.Huh
In-Reply-To: <20180406143559.GL17495@lunn.ch>
>
> What do you expect is connected to the MAC if there is no PHY?
>
Hi Andrew,
We connect the Ethernet switch to this MAC. The Ethernet switch port connected to MAC do not have the phy.
In this case, need to load the MAC driver and link speed/duplex set.
Thanks,
Raghu
^ permalink raw reply
* Re: [RFC bpf-next] bpf: document eBPF helpers and add a script to generate man page
From: Alexei Starovoitov @ 2018-04-10 1:47 UTC (permalink / raw)
To: Quentin Monnet
Cc: Daniel Borkmann, ast, netdev, oss-drivers, linux-doc, linux-man
In-Reply-To: <16d4d67a-ab36-3e58-1082-52f0898546e5@netronome.com>
On Mon, Apr 09, 2018 at 02:25:26PM +0100, Quentin Monnet wrote:
>
> Anyway, I am fine with keeping just signatures, descriptions and return
> values for now. I will submit a new version with only those items.
Thank you.
Could you also split it into few patches?
include/uapi/linux/bpf.h | 2237 ++++++++++++++++++++++++++++++++++++--------
scripts/bpf_helpers_doc.py | 568 +++++++++++
2 files changed, 2429 insertions(+), 376 deletions(-)
replying back and forth on a single patch of such size will be tedious
for others to follow.
May be document ~10 helpers at a time ? Total of ~7 patches and extra
patch for .py ?
^ permalink raw reply
* [PATCH v2] net: decnet: Replace GFP_ATOMIC with GFP_KERNEL in dn_route_init
From: Jia-Ju Bai @ 2018-04-10 1:18 UTC (permalink / raw)
To: davem, weiwan, kafai, hannes, fw, dsa, johannes.berg
Cc: linux-decnet-user, netdev, linux-kernel, Jia-Ju Bai
dn_route_init() is never called in atomic context.
The call chain ending up at dn_route_init() is:
[1] dn_route_init() <- decnet_init()
decnet_init() is only set as a parameter of module_init().
Despite never getting called from atomic context,
dn_route_init() calls __get_free_pages() with GFP_ATOMIC,
which does not sleep for allocation.
GFP_ATOMIC is not necessary and can be replaced with GFP_KERNEL,
which can sleep and improve the possibility of sucessful allocation.
This is found by a static analysis tool named DCNS written by myself.
And I also manually check it.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
---
v2:
* Modify the description of GFP_ATOMIC in v1.
Thank Eric for good advice.
---
net/decnet/dn_route.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/decnet/dn_route.c b/net/decnet/dn_route.c
index 0bd3afd..59ed12a 100644
--- a/net/decnet/dn_route.c
+++ b/net/decnet/dn_route.c
@@ -1898,7 +1898,7 @@ void __init dn_route_init(void)
while(dn_rt_hash_mask & (dn_rt_hash_mask - 1))
dn_rt_hash_mask--;
dn_rt_hash_table = (struct dn_rt_hash_bucket *)
- __get_free_pages(GFP_ATOMIC, order);
+ __get_free_pages(GFP_KERNEL, order);
} while (dn_rt_hash_table == NULL && --order > 0);
if (!dn_rt_hash_table)
--
1.9.1
^ permalink raw reply related
* [PATCH v2] net: tipc: Replace GFP_ATOMIC with GFP_KERNEL in tipc_mon_create
From: Jia-Ju Bai @ 2018-04-10 1:17 UTC (permalink / raw)
To: jon.maloy, ying.xue, davem
Cc: netdev, tipc-discussion, linux-kernel, Jia-Ju Bai
tipc_mon_create() is never called in atomic context.
The call chain ending up at dn_route_init() is:
[1] tipc_mon_create() <- tipc_enable_bearer() <- tipc_nl_bearer_enable()
tipc_nl_bearer_enable() calls rtnl_lock(), which indicates this function
is not called in atomic context.
Despite never getting called from atomic context,
tipc_mon_create() calls kzalloc() with GFP_ATOMIC,
which does not sleep for allocation.
GFP_ATOMIC is not necessary and can be replaced with GFP_KERNEL,
which can sleep and improve the possibility of sucessful allocation.
This is found by a static analysis tool named DCNS written by myself.
And I also manually check it.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
---
v2:
* Modify the description of GFP_ATOMIC in v1.
Thank Eric for good advice.
---
net/tipc/monitor.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/net/tipc/monitor.c b/net/tipc/monitor.c
index 9e109bb..9714d80 100644
--- a/net/tipc/monitor.c
+++ b/net/tipc/monitor.c
@@ -604,9 +604,9 @@ int tipc_mon_create(struct net *net, int bearer_id)
if (tn->monitors[bearer_id])
return 0;
- mon = kzalloc(sizeof(*mon), GFP_ATOMIC);
- self = kzalloc(sizeof(*self), GFP_ATOMIC);
- dom = kzalloc(sizeof(*dom), GFP_ATOMIC);
+ mon = kzalloc(sizeof(*mon), GFP_KERNEL);
+ self = kzalloc(sizeof(*self), GFP_KERNEL);
+ dom = kzalloc(sizeof(*dom), GFP_KERNEL);
if (!mon || !self || !dom) {
kfree(mon);
kfree(self);
--
1.9.1
^ permalink raw reply related
* [PATCH v2] net: nsci: Replace GFP_ATOMIC with GFP_KERNEL in ncsi_register_dev
From: Jia-Ju Bai @ 2018-04-10 1:16 UTC (permalink / raw)
To: davem, arnd, sam; +Cc: netdev, linux-kernel, Jia-Ju Bai
ncsi_register_dev() is never called in atomic context.
This function is only called by ftgmac100_probe() in
drivers/net/ethernet/faraday/ftgmac100.c.
And ftgmac100_probe() is only set as ".probe" in "struct platform_driver".
Despite never getting called from atomic context,
ncsi_register_dev() calls kzalloc() with GFP_ATOMIC,
which does not sleep for allocation.
GFP_ATOMIC is not necessary and can be replaced with GFP_KERNEL,
which can sleep and improve the possibility of sucessful allocation.
This is found by a static analysis tool named DCNS written by myself.
And I also manually check it.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
---
v2:
* Modify the description of GFP_ATOMIC in v1.
Thank Eric for good advice.
---
net/ncsi/ncsi-manage.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/ncsi/ncsi-manage.c b/net/ncsi/ncsi-manage.c
index 3fd3c39..6b5b5a0 100644
--- a/net/ncsi/ncsi-manage.c
+++ b/net/ncsi/ncsi-manage.c
@@ -1508,7 +1508,7 @@ struct ncsi_dev *ncsi_register_dev(struct net_device *dev,
return nd;
/* Create NCSI device */
- ndp = kzalloc(sizeof(*ndp), GFP_ATOMIC);
+ ndp = kzalloc(sizeof(*ndp), GFP_KERNEL);
if (!ndp)
return NULL;
--
1.9.1
^ permalink raw reply related
* [PATCH v2] net: tipc: Replace GFP_ATOMIC with GFP_KERNEL in tipc_mon_create
From: Jia-Ju Bai @ 2018-04-10 1:16 UTC (permalink / raw)
To: gerrit, davem; +Cc: dccp, netdev, linux-kernel, Jia-Ju Bai
tipc_mon_create() is never called in atomic context.
The call chain ending up at dn_route_init() is:
[1] tipc_mon_create() <- tipc_enable_bearer() <- tipc_nl_bearer_enable()
tipc_nl_bearer_enable() calls rtnl_lock(), which indicates this function
is not called in atomic context.
Despite never getting called from atomic context,
tipc_mon_create() calls kzalloc() with GFP_ATOMIC,
which does not sleep for allocation.
GFP_ATOMIC is not necessary and can be replaced with GFP_KERNEL,
which can sleep and improve the possibility of sucessful allocation.
This is found by a static analysis tool named DCNS written by myself.
And I also manually check it.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
---
v2:
* Modify the description of GFP_ATOMIC in v1.
Thank Eric for good advice.
---
net/tipc/monitor.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/net/tipc/monitor.c b/net/tipc/monitor.c
index 9e109bb..9714d80 100644
--- a/net/tipc/monitor.c
+++ b/net/tipc/monitor.c
@@ -604,9 +604,9 @@ int tipc_mon_create(struct net *net, int bearer_id)
if (tn->monitors[bearer_id])
return 0;
- mon = kzalloc(sizeof(*mon), GFP_ATOMIC);
- self = kzalloc(sizeof(*self), GFP_ATOMIC);
- dom = kzalloc(sizeof(*dom), GFP_ATOMIC);
+ mon = kzalloc(sizeof(*mon), GFP_KERNEL);
+ self = kzalloc(sizeof(*self), GFP_KERNEL);
+ dom = kzalloc(sizeof(*dom), GFP_KERNEL);
if (!mon || !self || !dom) {
kfree(mon);
kfree(self);
--
1.9.1
^ permalink raw reply related
* [PATCH v2] net: decnet: Replace GFP_ATOMIC with GFP_KERNEL in dn_route_init
From: Jia-Ju Bai @ 2018-04-10 1:15 UTC (permalink / raw)
To: gerrit, davem; +Cc: dccp, netdev, linux-kernel, Jia-Ju Bai
dn_route_init() is never called in atomic context.
The call chain ending up at dn_route_init() is:
[1] dn_route_init() <- decnet_init()
decnet_init() is only set as a parameter of module_init().
Despite never getting called from atomic context,
dn_route_init() calls __get_free_pages() with GFP_ATOMIC,
which does not sleep for allocation.
GFP_ATOMIC is not necessary and can be replaced with GFP_KERNEL,
which can sleep and improve the possibility of sucessful allocation.
This is found by a static analysis tool named DCNS written by myself.
And I also manually check it.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
---
v2:
* Modify the description of GFP_ATOMIC in v1.
Thank Eric for good advice.
---
net/decnet/dn_route.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/decnet/dn_route.c b/net/decnet/dn_route.c
index 0bd3afd..59ed12a 100644
--- a/net/decnet/dn_route.c
+++ b/net/decnet/dn_route.c
@@ -1898,7 +1898,7 @@ void __init dn_route_init(void)
while(dn_rt_hash_mask & (dn_rt_hash_mask - 1))
dn_rt_hash_mask--;
dn_rt_hash_table = (struct dn_rt_hash_bucket *)
- __get_free_pages(GFP_ATOMIC, order);
+ __get_free_pages(GFP_KERNEL, order);
} while (dn_rt_hash_table == NULL && --order > 0);
if (!dn_rt_hash_table)
--
1.9.1
^ permalink raw reply related
* [PATCH v2] net: dccp: Replace GFP_ATOMIC with GFP_KERNEL in dccp_init
From: Jia-Ju Bai @ 2018-04-10 1:14 UTC (permalink / raw)
To: gerrit, davem; +Cc: dccp, netdev, linux-kernel, Jia-Ju Bai
dccp_init() is never called in atomic context.
This function is only set as a parameter of module_init().
Despite never getting called from atomic context,
dccp_init() calls __get_free_pages() with GFP_ATOMIC,
which does not sleep for allocation.
GFP_ATOMIC is not necessary and can be replaced with GFP_KERNEL,
which can sleep and improve the possibility of sucessful allocation.
This is found by a static analysis tool named DCNS written by myself.
And I also manually check it.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
---
v2:
* Modify the description of GFP_ATOMIC in v1.
Thank Eric for good advice.
---
net/dccp/proto.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index b68168f..f63ba93 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -1159,7 +1159,7 @@ static int __init dccp_init(void)
hash_size--;
dccp_hashinfo.ehash_mask = hash_size - 1;
dccp_hashinfo.ehash = (struct inet_ehash_bucket *)
- __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, ehash_order);
+ __get_free_pages(GFP_KERNEL|__GFP_NOWARN, ehash_order);
} while (!dccp_hashinfo.ehash && --ehash_order > 0);
if (!dccp_hashinfo.ehash) {
@@ -1182,7 +1182,7 @@ static int __init dccp_init(void)
bhash_order > 0)
continue;
dccp_hashinfo.bhash = (struct inet_bind_hashbucket *)
- __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, bhash_order);
+ __get_free_pages(GFP_KERNEL|__GFP_NOWARN, bhash_order);
} while (!dccp_hashinfo.bhash && --bhash_order >= 0);
if (!dccp_hashinfo.bhash) {
--
1.9.1
^ permalink raw reply related
* Re: [PATCH RESEND net] vhost: fix vhost_vq_access_ok() log check
From: Stefan Hajnoczi @ 2018-04-10 1:05 UTC (permalink / raw)
To: Michael S. Tsirkin
Cc: David Miller, netdev, Linux Virtualization, kvm, syzkaller-bugs,
linux-kernel, Stefan Hajnoczi
In-Reply-To: <20180409174731-mutt-send-email-mst@kernel.org>
On Tue, Apr 10, 2018 at 3:40 AM, Michael S. Tsirkin <mst@redhat.com> wrote:
> From: Stefan Hajnoczi <stefanha@redhat.com>
>
> Commit d65026c6c62e7d9616c8ceb5a53b68bcdc050525 ("vhost: validate log
> when IOTLB is enabled") introduced a regression. The logic was
> originally:
>
> if (vq->iotlb)
> return 1;
> return A && B;
>
> After the patch the short-circuit logic for A was inverted:
>
> if (A || vq->iotlb)
> return A;
> return B;
>
> The correct logic is:
>
> if (!A || vq->iotlb)
> return A;
> return B;
>
> Reported-by: syzbot+65a84dde0214b0387ccd@syzkaller.appspotmail.com
> Cc: Jason Wang <jasowang@redhat.com>
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> Acked-by: Michael S. Tsirkin <mst@redhat.com>
>
> ---
> drivers/vhost/vhost.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
NACK
I will send a v2 with cleaner logic as suggested by Linus.
Stefan
^ permalink raw reply
* Re: [PATCH bpf] bpf/tracing: fix a deadlock in perf_event_detach_bpf_prog
From: Alexei Starovoitov @ 2018-04-10 0:51 UTC (permalink / raw)
To: Yonghong Song, daniel, netdev; +Cc: kernel-team
In-Reply-To: <a2e305b4-760f-6e19-6043-81d1a1f85e48@fb.com>
On 4/9/18 11:41 AM, Yonghong Song wrote:
>
>
> On 4/9/18 9:47 AM, Alexei Starovoitov wrote:
>> On 4/9/18 9:18 AM, Yonghong Song wrote:
>>> syzbot reported a possible deadlock in perf_event_detach_bpf_prog.
>> ...
>>> @@ -985,16 +986,31 @@ int perf_event_query_prog_array(struct
>>> perf_event *event, void __user *info)
>>> return -EINVAL;
>>> if (copy_from_user(&query, uquery, sizeof(query)))
>>> return -EFAULT;
>>> - if (query.ids_len > BPF_TRACE_MAX_PROGS)
>>> +
>>> + ids_len = query.ids_len;
>>> + if (ids_len > BPF_TRACE_MAX_PROGS)
>>> return -E2BIG;
>>> + ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN);
>>> + if (!ids)
>>> + return -ENOMEM;
>>>
>>> mutex_lock(&bpf_event_mutex);
>>> ret = bpf_prog_array_copy_info(event->tp_event->prog_array,
>>> - uquery->ids,
>>> - query.ids_len,
>>> - &uquery->prog_cnt);
>>> + ids,
>>> + ids_len,
>>> + &prog_cnt);
>>> mutex_unlock(&bpf_event_mutex);
>>>
>>> + if (!ret || ret == -ENOSPC) {
>>> + if (copy_to_user(&uquery->prog_cnt, &prog_cnt,
>>> sizeof(prog_cnt)) ||
>>> + copy_to_user(uquery->ids, ids, ids_len * sizeof(u32))) {
>>> + ret = -EFAULT;
>>> + goto out;
>>> + }
>>> + }
>>> +
>>> +out:
>>> + kfree(ids);
>>
>> alloc/free just to avoid this locking dependency feels suboptimal.
>
> We actually already did kcalloc/kfree in bpf_prog_array_copy_to_user.
> In that function, we did not copy_to_user one id at a time.
> We allocate a temporary array and store the result there
> and at the end, we call one copy_to_user to copy to the user buffer.
>
> The patch here just moved this allocation and associated copy_to_user
> out of the function and bpf_event_mutex. It did not introduce new
> allocations.
I see, so the patch essentially open coding
bpf_prog_array_copy_to_user()
can we share the code then?
bpf/core.c callsite used by trace/bpf_trace.c
and similar callsite in bpf/cgroup.c
should be using common helper.
>>
>> may be we can get rid of bpf_event_mutex in some cases?
>> the perf event itself is locked via perf_event_ctx_lock() when we're
>> calling perf_event_query_prog_array, perf_event_attach|detach_bpf_prog.
>> I forgot what was the motivation for us to introduce it in the
>> first place.
>
> The original motivation for the lock to make sure bpf_prog_array
> does not change during middle of attach/detach/query. it looks like
> we have:
> . perf_event_attach|query under perf_event_ctx_lock
> . perf_event_detach not under perf_event_ctx_lock
> Introducing perf_event_ctx_lock to perf_event_detach could still
> have the deadlock.
ahh, right, since the progs are in even->tp_event which can
be shared by multiple perf_events.
Scratch that idea.
^ permalink raw reply
* Re: [RFC PATCH 2/3] netdev: kernel-only IFF_HIDDEN netdevice
From: Siwei Liu @ 2018-04-09 23:31 UTC (permalink / raw)
To: Stephen Hemminger
Cc: Andrew Lunn, David Miller, David Ahern, Jiri Pirko, si-wei liu,
Michael S. Tsirkin, Alexander Duyck, Brandeburg, Jesse,
Jakub Kicinski, Jason Wang, Samudrala, Sridhar, Netdev,
virtualization, virtio-dev
In-Reply-To: <20180409160348.12f8a6d9@xeon-e3>
On Mon, Apr 9, 2018 at 4:03 PM, Stephen Hemminger
<stephen@networkplumber.org> wrote:
> On Mon, 9 Apr 2018 15:30:42 -0700
> Siwei Liu <loseweigh@gmail.com> wrote:
>
>> On Mon, Apr 9, 2018 at 3:15 PM, Andrew Lunn <andrew@lunn.ch> wrote:
>> >> No, implementation wise I'd avoid changing the class on the fly. What
>> >> I'm looking to is a means to add a secondary class or class aliasing
>> >> mechanism for netdevs that allows mapping for a kernel device
>> >> namespace (/class/net-kernel) to userspace (/class/net). Imagine
>> >> creating symlinks between these two namespaces as an analogy. All
>> >> userspace visible netdevs today will have both a kernel name and a
>> >> userspace visible name, having one (/class/net) referecing the other
>> >> (/class/net-kernel) in its own namespace. The newly introduced
>> >> IFF_AUTO_MANAGED device will have a kernel name only
>> >> (/class/net-kernel). As a result, the existing applications using
>> >> /class/net don't break, while we're adding the kernel namespace that
>> >> allows IFF_AUTO_MANAGED devices which will not be exposed to userspace
>> >> at all.
>> >
>> > My gut feeling is this whole scheme will not fly. You really should be
>> > talking to GregKH.
>>
>> Will do. Before spreading it out loudly I'd run it within netdev to
>> clarify the need for why not exposing the lower netdevs is critical
>> for cloud service providers in the face of introducing a new feature,
>> and we are not hiding anything but exposing it in a way that don't
>> break existing userspace applications while introducing feature is
>> possible with the limitation of keeping old userspace still.
>>
>> >
>> > Anyway, please remember that IFF_AUTO_MANAGED will need to be dynamic.
>> > A device can start out as a normal device, and will change to being
>> > automatic later, when the user on top of it probes.
>>
>> Sure. In whatever form it's still a netdev, and changing the namespace
>> should be more dynamic than changing the class.
>>
>> Thanks a lot,
>> -Siwei
>>
>> >
>> > Andrew
>
> Also, remember for netdev's /sys is really a third class API.
> The primary API's are netlink and ioctl. Also why not use existing
> network namespaces rather than inventing a new abstraction?
Because we want to leave old userspace unmodified while making SR-IOV
live migration transparent to users. Specifically, we'd want old udevd
to skip through uevents for the lower netdevs, while also making new
udevd able to name the bypass_master interface by referencing the pci
slot information which is only present in the sysfs entry for
IFF_AUTO_MANAGED net device.
The problem of using network namespace is that, no sysfs entry will be
around for IFF_AUTO_MANAGED netdev if we isolate it out to a separate
netns, unless we generalize the scope for what netns is designed for
(isolation I mean). For auto-managed netdevs we don't neccessarily
wants strict isolation, but rather a way of sticking to 1-netdev model
for strict backward compatibility requiement of the old userspace,
while exposing the information in a way new userspace understands.
Thanks,
-Siwei
^ permalink raw reply
* Re: [PATCH net-next] netns: filter uevents correctly
From: Eric W. Biederman @ 2018-04-09 23:21 UTC (permalink / raw)
To: Christian Brauner
Cc: Kirill Tkhai, davem, gregkh, netdev, linux-kernel, avagin, serge
In-Reply-To: <20180409154627.GA15157@gmail.com>
Christian Brauner <christian.brauner@canonical.com> writes:
> On Thu, Apr 05, 2018 at 10:59:49PM -0500, Eric W. Biederman wrote:
>> Christian Brauner <christian.brauner@canonical.com> writes:
>>
>> > On Thu, Apr 05, 2018 at 05:26:59PM +0300, Kirill Tkhai wrote:
>> >> On 05.04.2018 17:07, Christian Brauner wrote:
>> >> > On Thu, Apr 05, 2018 at 04:01:03PM +0300, Kirill Tkhai wrote:
>> >> >> On 04.04.2018 22:48, Christian Brauner wrote:
>> >> >>> commit 07e98962fa77 ("kobject: Send hotplug events in all network namespaces")
>> >> >>>
>> >> >>> enabled sending hotplug events into all network namespaces back in 2010.
>> >> >>> Over time the set of uevents that get sent into all network namespaces has
>> >> >>> shrunk. We have now reached the point where hotplug events for all devices
>> >> >>> that carry a namespace tag are filtered according to that namespace.
>> >> >>>
>> >> >>> Specifically, they are filtered whenever the namespace tag of the kobject
>> >> >>> does not match the namespace tag of the netlink socket. One example are
>> >> >>> network devices. Uevents for network devices only show up in the network
>> >> >>> namespaces these devices are moved to or created in.
>> >> >>>
>> >> >>> However, any uevent for a kobject that does not have a namespace tag
>> >> >>> associated with it will not be filtered and we will *try* to broadcast it
>> >> >>> into all network namespaces.
>> >> >>>
>> >> >>> The original patchset was written in 2010 before user namespaces were a
>> >> >>> thing. With the introduction of user namespaces sending out uevents became
>> >> >>> partially isolated as they were filtered by user namespaces:
>> >> >>>
>> >> >>> net/netlink/af_netlink.c:do_one_broadcast()
>> >> >>>
>> >> >>> if (!net_eq(sock_net(sk), p->net)) {
>> >> >>> if (!(nlk->flags & NETLINK_F_LISTEN_ALL_NSID))
>> >> >>> return;
>> >> >>>
>> >> >>> if (!peernet_has_id(sock_net(sk), p->net))
>> >> >>> return;
>> >> >>>
>> >> >>> if (!file_ns_capable(sk->sk_socket->file, p->net->user_ns,
>> >> >>> CAP_NET_BROADCAST))
>> >> >>> j return;
>> >> >>> }
>> >> >>>
>> >> >>> The file_ns_capable() check will check whether the caller had
>> >> >>> CAP_NET_BROADCAST at the time of opening the netlink socket in the user
>> >> >>> namespace of interest. This check is fine in general but seems insufficient
>> >> >>> to me when paired with uevents. The reason is that devices always belong to
>> >> >>> the initial user namespace so uevents for kobjects that do not carry a
>> >> >>> namespace tag should never be sent into another user namespace. This has
>> >> >>> been the intention all along. But there's one case where this breaks,
>> >> >>> namely if a new user namespace is created by root on the host and an
>> >> >>> identity mapping is established between root on the host and root in the
>> >> >>> new user namespace. Here's a reproducer:
>> >> >>>
>> >> >>> sudo unshare -U --map-root
>> >> >>> udevadm monitor -k
>> >> >>> # Now change to initial user namespace and e.g. do
>> >> >>> modprobe kvm
>> >> >>> # or
>> >> >>> rmmod kvm
>> >> >>>
>> >> >>> will allow the non-initial user namespace to retrieve all uevents from the
>> >> >>> host. This seems very anecdotal given that in the general case user
>> >> >>> namespaces do not see any uevents and also can't really do anything useful
>> >> >>> with them.
>> >> >>>
>> >> >>> Additionally, it is now possible to send uevents from userspace. As such we
>> >> >>> can let a sufficiently privileged (CAP_SYS_ADMIN in the owning user
>> >> >>> namespace of the network namespace of the netlink socket) userspace process
>> >> >>> make a decision what uevents should be sent.
>> >> >>>
>> >> >>> This makes me think that we should simply ensure that uevents for kobjects
>> >> >>> that do not carry a namespace tag are *always* filtered by user namespace
>> >> >>> in kobj_bcast_filter(). Specifically:
>> >> >>> - If the owning user namespace of the uevent socket is not init_user_ns the
>> >> >>> event will always be filtered.
>> >> >>> - If the network namespace the uevent socket belongs to was created in the
>> >> >>> initial user namespace but was opened from a non-initial user namespace
>> >> >>> the event will be filtered as well.
>> >> >>> Put another way, uevents for kobjects not carrying a namespace tag are now
>> >> >>> always only sent to the initial user namespace. The regression potential
>> >> >>> for this is near to non-existent since user namespaces can't really do
>> >> >>> anything with interesting devices.
>> >> >>>
>> >> >>> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
>> >> >>> ---
>> >> >>> lib/kobject_uevent.c | 10 +++++++++-
>> >> >>> 1 file changed, 9 insertions(+), 1 deletion(-)
>> >> >>>
>> >> >>> diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
>> >> >>> index 15ea216a67ce..cb98cddb6e3b 100644
>> >> >>> --- a/lib/kobject_uevent.c
>> >> >>> +++ b/lib/kobject_uevent.c
>> >> >>> @@ -251,7 +251,15 @@ static int kobj_bcast_filter(struct sock *dsk, struct sk_buff *skb, void *data)
>> >> >>> return sock_ns != ns;
>> >> >>> }
>> >> >>>
>> >> >>> - return 0;
>> >> >>> + /*
>> >> >>> + * The kobject does not carry a namespace tag so filter by user
>> >> >>> + * namespace below.
>> >> >>> + */
>> >> >>> + if (sock_net(dsk)->user_ns != &init_user_ns)
>> >> >>> + return 1;
>> >> >>> +
>> >> >>> + /* Check if socket was opened from non-initial user namespace. */
>> >> >>> + return sk_user_ns(dsk) != &init_user_ns;
>> >> >>> }
>> >> >>> #endif
>> >> >>
>> >> >> So, this prohibits to listen events of all devices except network-related
>> >> >> in containers? If it's so, I don't think it's a good solution. Uevents is not
>> >> >
>> >> > No, this is not correct: As it is right now *without my patch* no
>> >> > non-initial user namespace is receiving *any uevents* but those
>> >> > specifically namespaced such as those for network devices. This patch
>> >> > doesn't change that at all. The commit message outlines this in detail
>> >> > how this comes about.
>> >> > There is only one case where this currently breaks and this is as I
>> >> > outlined explicitly in my commit message when you create a new user
>> >> > namespace and map container(0) -> host(0). This patch fixes this.
>> >>
>> >> Could you please point the place, where non-initial user namespaces are filtered?
>> >> I only see the kobj_bcast_filter() logic, and it used to return 0, which means "accepted".
>> >> Now it will return 1 sometimes.
>> >
>> > Oh sure, it's in the commit message though. The callchain is
>> > lib/kobject_uevent.c:kobject_uevent_net_broadcast() ->
>> > nnet/netlink/af_netlink.c:netlink_broadcast_filtered() ->
>> > net/netlink/af_netlink.c:do_one_broadcast():
>> >
>> > This codepiece will check whether the openened socket holds
>> > CAP_NET_BROADCAST in the user namespace of the target network namespace
>> > which it won't because we don't have device namespaces and all devices
>> > belong to the initial set of namespaces.
>> >
>> > if (!file_ns_capable(sk->sk_socket->file, p->net->user_ns,
>> > CAP_NET_BROADCAST))
>> > j return;
>> >
>>
>> The above that only applies if someone has set NETLINK_F_LISTEN_ALL_NSID
>> on their socket and has had someone with the appropriate privileges
>> assign a peerrnetid.
>>
>> All of which is to say that file_ns_capable is not nearly as applicable
>> as it might be, and if you can pass the other two checks I think it is
>> pointless (because the peernet attributes are not generated for
>> kobj_uevents) but valid to receive events from outside your network
>> namespace.
>>
>>
>> I might be missing something but I don't see anything excluding network
>> namespaces owned by !init_user_ns excluded from the kobject_uevent
>> logic.
>>
>> The uevent_sock_list has one entry per network namespace. And
>> kobject_uevent_net_broacast appears to walk each one.
>>
>> I had a memory of filtering uevent messages and I had a memory
>> that the netlink_has_listeners had a per network namespace effect.
>> Neither seems true from my inspection of the code tonight.
>>
>> If we are not filtering ordinary uevents at least at the user namespace
>> level that does seem to be at least a nuisance.
>>
>>
>> Christian can you dig a little deeper into this. I have a feeling that
>> there are some real efficiency improvements that we could make to
>> kobject_uevent_net_broadcast if nothing else.
>>
>> Perhaps you could see where uevents are broadcast by poking
>> the sysfs uevent of an existing device, and triggering a retransmit.
>
> @Eric, so I did some intensive testing over the weekend and forget everything I
> said before. Uevents are not filtered by the kernel at the moment. This is
> currently - apart from network devices - a pure userspace thing. Specifically,
> anyone on the host can listen to all uevents from everywhere. It's neither
> filtered by user nor by network namespace. The fact that I used
>
> udevadm --debug monitor
>
> to test my prior hypothesis was what led me to believe that uevents are already
> correctly filtered.
> Instead, what is actually happening is that every udev implementation out there
> is discarding uevents that were send by uids != 0 in the CMSG_DATA.
> Specifically,
Yes. I remember something of the sort. I believe udev also filters to
ensure that the netlink port id == 0 to ensure the message came from
the kernel and was not spoofed in any way.
> - legacy standalone udevd:
> https://git.kernel.org/pub/scm/linux/hotplug/udev.git/snapshot/udev-062.tar.gz
> - eudevd
> https://github.com/gentoo/eudev/blob/6f630d32bf494a457171b3f99e329592497bf271/src/libudev/libudev-monitor.c#L645
> - systemd-udevd
> https://github.com/systemd/systemd/blob/e89ab7f219a399ab719c78cf43c07c0da60bd151/src/libudev/libudev-monitor.c#L656
> - ueventd (Android)
> https://android.googlesource.com/platform/system/core.git/+/android-8.1.0_r22/libcutils/uevent.c#81
>
> For all of those I could trace this behavior back to the first released
> version. (To be precise, for legacy udevd that eventually became systemd-udevd
> I could trace it back to the first version that is still available on
> git.kernel.org which is 062. Since eudevd is a fork of systemd-udevd it is
> trivially true that it has the same behavior from the beginning.)
> Android filters uevents in the same way but removed that check on January 8
> 2018 for what I think is invalid reasoning. The good news is that this is only
> in their master branch. It hasn't even made it into an rc release for Android 8
> yet. I filed a bug against Android and offered them a fix if they agree.
>
> In any case, userspace udev is not making use of uevents at all right now since
> any uid != 0 events are **explicitly** discarded.
> The fact that you receive uevents for
>
> sudo unshare -U --map-root -n
> udevadm --debug monitor
>
> is simply explained by the fact that container(0) <=> host(0) at which point
> the uid in CMSG_DATA will be 0 in the new user namespace and udev will not
> discard it.
> The use case for receiving uevents in containers/user namespaces is definitely
> there but that's what the uevent injection patch series was for that we merged.
> This is a much safer and saner solution.
> The fact that all udev implementations filter uevents by uid != 0 very much
> seems like a security mechanism in userspace that we probably should provide by
> isolating uevents based on user and/or network namespaces.
So in summary. Uevents are filtered in a user namespace (by userspace)
because the received uid != 0. It instead == 65534 == "nobody" because
the global root uid is not mapped.
Which means that we can modify the kernel to not send to all network
namespaces whose user_ns != &init_user_ns because we know that userspace
will ignore the message because of the uid anyway. Which means when
net-next reopens you can send that patch. But please base it on just
not including network namespaces in the list, as that is much more
efficient than adding more conditions to the filter.
Thank you for tracking down what is going on.
Eric
^ permalink raw reply
* Re: [RFC PATCH 2/3] netdev: kernel-only IFF_HIDDEN netdevice
From: Stephen Hemminger @ 2018-04-09 23:03 UTC (permalink / raw)
To: Siwei Liu
Cc: Andrew Lunn, David Miller, David Ahern, Jiri Pirko, si-wei liu,
Michael S. Tsirkin, Alexander Duyck, Brandeburg, Jesse,
Jakub Kicinski, Jason Wang, Samudrala, Sridhar, Netdev,
virtualization, virtio-dev
In-Reply-To: <CADGSJ23RnioMdi0U0yeOBKuM-9QUZ3S33as693xzs0VWQbuVcA@mail.gmail.com>
On Mon, 9 Apr 2018 15:30:42 -0700
Siwei Liu <loseweigh@gmail.com> wrote:
> On Mon, Apr 9, 2018 at 3:15 PM, Andrew Lunn <andrew@lunn.ch> wrote:
> >> No, implementation wise I'd avoid changing the class on the fly. What
> >> I'm looking to is a means to add a secondary class or class aliasing
> >> mechanism for netdevs that allows mapping for a kernel device
> >> namespace (/class/net-kernel) to userspace (/class/net). Imagine
> >> creating symlinks between these two namespaces as an analogy. All
> >> userspace visible netdevs today will have both a kernel name and a
> >> userspace visible name, having one (/class/net) referecing the other
> >> (/class/net-kernel) in its own namespace. The newly introduced
> >> IFF_AUTO_MANAGED device will have a kernel name only
> >> (/class/net-kernel). As a result, the existing applications using
> >> /class/net don't break, while we're adding the kernel namespace that
> >> allows IFF_AUTO_MANAGED devices which will not be exposed to userspace
> >> at all.
> >
> > My gut feeling is this whole scheme will not fly. You really should be
> > talking to GregKH.
>
> Will do. Before spreading it out loudly I'd run it within netdev to
> clarify the need for why not exposing the lower netdevs is critical
> for cloud service providers in the face of introducing a new feature,
> and we are not hiding anything but exposing it in a way that don't
> break existing userspace applications while introducing feature is
> possible with the limitation of keeping old userspace still.
>
> >
> > Anyway, please remember that IFF_AUTO_MANAGED will need to be dynamic.
> > A device can start out as a normal device, and will change to being
> > automatic later, when the user on top of it probes.
>
> Sure. In whatever form it's still a netdev, and changing the namespace
> should be more dynamic than changing the class.
>
> Thanks a lot,
> -Siwei
>
> >
> > Andrew
Also, remember for netdev's /sys is really a third class API.
The primary API's are netlink and ioctl. Also why not use existing
network namespaces rather than inventing a new abstraction?
^ permalink raw reply
* Re: [PATCH] iscsi: respond to netlink with unicast when appropriate
From: Lee Duncan @ 2018-04-09 23:03 UTC (permalink / raw)
To: Chris Leech, linux-scsi, netdev, open-iscsi
In-Reply-To: <20180409221528.67880-1-cleech@redhat.com>
On 04/09/2018 03:15 PM, Chris Leech wrote:
> Instead of always multicasting responses, send a unicast netlink message
> directed at the correct pid. This will be needed if we ever want to
> support multiple userspace processes interacting with the kernel over
> iSCSI netlink simultaneously. Limitations can currently be seen if you
> attempt to run multiple iscsistart commands in parallel.
>
> We've fixed up the userspace issues in iscsistart that prevented
> multiple instances from running, so now attempts to speed up booting by
> bringing up multiple iscsi sessions at once in the initramfs are just
> running into misrouted responses that this fixes.
As you may know, I disagree with running multiple iscsistart-s at the
same time, since that's what iscsid is for.
Never the less, I believe we _should_ be able to have multiple processes
talking to the kernel target code, so I agree with these changes.
>
> Signed-off-by: Chris Leech <cleech@redhat.com>
> ---
> drivers/scsi/scsi_transport_iscsi.c | 29 ++++++++++++++++++-----------
> 1 file changed, 18 insertions(+), 11 deletions(-)
>
> ... (diffs removed to save electrons)
>
Reviewed-by: Lee Duncan <lduncan@suse.com>
--
Lee Duncan
SUSE Labs
^ permalink raw reply
* Re: [RFC PATCH 2/3] netdev: kernel-only IFF_HIDDEN netdevice
From: Siwei Liu @ 2018-04-09 22:30 UTC (permalink / raw)
To: Andrew Lunn
Cc: Alexander Duyck, virtio-dev, Jiri Pirko, Michael S. Tsirkin,
Jakub Kicinski, Samudrala, Sridhar, virtualization, Netdev,
David Ahern, si-wei liu, David Miller
In-Reply-To: <20180409221523.GH562@lunn.ch>
On Mon, Apr 9, 2018 at 3:15 PM, Andrew Lunn <andrew@lunn.ch> wrote:
>> No, implementation wise I'd avoid changing the class on the fly. What
>> I'm looking to is a means to add a secondary class or class aliasing
>> mechanism for netdevs that allows mapping for a kernel device
>> namespace (/class/net-kernel) to userspace (/class/net). Imagine
>> creating symlinks between these two namespaces as an analogy. All
>> userspace visible netdevs today will have both a kernel name and a
>> userspace visible name, having one (/class/net) referecing the other
>> (/class/net-kernel) in its own namespace. The newly introduced
>> IFF_AUTO_MANAGED device will have a kernel name only
>> (/class/net-kernel). As a result, the existing applications using
>> /class/net don't break, while we're adding the kernel namespace that
>> allows IFF_AUTO_MANAGED devices which will not be exposed to userspace
>> at all.
>
> My gut feeling is this whole scheme will not fly. You really should be
> talking to GregKH.
Will do. Before spreading it out loudly I'd run it within netdev to
clarify the need for why not exposing the lower netdevs is critical
for cloud service providers in the face of introducing a new feature,
and we are not hiding anything but exposing it in a way that don't
break existing userspace applications while introducing feature is
possible with the limitation of keeping old userspace still.
>
> Anyway, please remember that IFF_AUTO_MANAGED will need to be dynamic.
> A device can start out as a normal device, and will change to being
> automatic later, when the user on top of it probes.
Sure. In whatever form it's still a netdev, and changing the namespace
should be more dynamic than changing the class.
Thanks a lot,
-Siwei
>
> Andrew
^ permalink raw reply
* [PATCH] iscsi: respond to netlink with unicast when appropriate
From: Chris Leech @ 2018-04-09 22:15 UTC (permalink / raw)
To: linux-scsi, netdev, Lee Duncan, open-iscsi; +Cc: Chris Leech
Instead of always multicasting responses, send a unicast netlink message
directed at the correct pid. This will be needed if we ever want to
support multiple userspace processes interacting with the kernel over
iSCSI netlink simultaneously. Limitations can currently be seen if you
attempt to run multiple iscsistart commands in parallel.
We've fixed up the userspace issues in iscsistart that prevented
multiple instances from running, so now attempts to speed up booting by
bringing up multiple iscsi sessions at once in the initramfs are just
running into misrouted responses that this fixes.
Signed-off-by: Chris Leech <cleech@redhat.com>
---
drivers/scsi/scsi_transport_iscsi.c | 29 ++++++++++++++++++-----------
1 file changed, 18 insertions(+), 11 deletions(-)
diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index f4b52b44b966..65f6c94f2e9b 100644
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -2322,6 +2322,12 @@ iscsi_multicast_skb(struct sk_buff *skb, uint32_t group, gfp_t gfp)
return nlmsg_multicast(nls, skb, 0, group, gfp);
}
+static int
+iscsi_unicast_skb(struct sk_buff *skb, u32 portid)
+{
+ return nlmsg_unicast(nls, skb, portid);
+}
+
int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
char *data, uint32_t data_size)
{
@@ -2524,14 +2530,11 @@ void iscsi_ping_comp_event(uint32_t host_no, struct iscsi_transport *transport,
EXPORT_SYMBOL_GPL(iscsi_ping_comp_event);
static int
-iscsi_if_send_reply(uint32_t group, int seq, int type, int done, int multi,
- void *payload, int size)
+iscsi_if_send_reply(u32 portid, int type, void *payload, int size)
{
struct sk_buff *skb;
struct nlmsghdr *nlh;
int len = nlmsg_total_size(size);
- int flags = multi ? NLM_F_MULTI : 0;
- int t = done ? NLMSG_DONE : type;
skb = alloc_skb(len, GFP_ATOMIC);
if (!skb) {
@@ -2539,10 +2542,9 @@ iscsi_if_send_reply(uint32_t group, int seq, int type, int done, int multi,
return -ENOMEM;
}
- nlh = __nlmsg_put(skb, 0, 0, t, (len - sizeof(*nlh)), 0);
- nlh->nlmsg_flags = flags;
+ nlh = __nlmsg_put(skb, 0, 0, type, (len - sizeof(*nlh)), 0);
memcpy(nlmsg_data(nlh), payload, size);
- return iscsi_multicast_skb(skb, group, GFP_ATOMIC);
+ return iscsi_unicast_skb(skb, portid);
}
static int
@@ -3470,6 +3472,7 @@ static int
iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, uint32_t *group)
{
int err = 0;
+ u32 portid;
struct iscsi_uevent *ev = nlmsg_data(nlh);
struct iscsi_transport *transport = NULL;
struct iscsi_internal *priv;
@@ -3490,10 +3493,12 @@ iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, uint32_t *group)
if (!try_module_get(transport->owner))
return -EINVAL;
+ portid = NETLINK_CB(skb).portid;
+
switch (nlh->nlmsg_type) {
case ISCSI_UEVENT_CREATE_SESSION:
err = iscsi_if_create_session(priv, ep, ev,
- NETLINK_CB(skb).portid,
+ portid,
ev->u.c_session.initial_cmdsn,
ev->u.c_session.cmds_max,
ev->u.c_session.queue_depth);
@@ -3506,7 +3511,7 @@ iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, uint32_t *group)
}
err = iscsi_if_create_session(priv, ep, ev,
- NETLINK_CB(skb).portid,
+ portid,
ev->u.c_bound_session.initial_cmdsn,
ev->u.c_bound_session.cmds_max,
ev->u.c_bound_session.queue_depth);
@@ -3664,6 +3669,8 @@ iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, uint32_t *group)
static void
iscsi_if_rx(struct sk_buff *skb)
{
+ u32 portid = NETLINK_CB(skb).portid;
+
mutex_lock(&rx_queue_mutex);
while (skb->len >= NLMSG_HDRLEN) {
int err;
@@ -3699,8 +3706,8 @@ iscsi_if_rx(struct sk_buff *skb)
break;
if (ev->type == ISCSI_UEVENT_GET_CHAP && !err)
break;
- err = iscsi_if_send_reply(group, nlh->nlmsg_seq,
- nlh->nlmsg_type, 0, 0, ev, sizeof(*ev));
+ err = iscsi_if_send_reply(portid, nlh->nlmsg_type,
+ ev, sizeof(*ev));
} while (err < 0 && err != -ECONNREFUSED && err != -ESRCH);
skb_pull(skb, rlen);
}
--
2.14.3
^ permalink raw reply related
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