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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Minios-devel] [UNIKRAFT PATCH 8/9] plat/xen/drivers/9p: Implement request and recv
Reviewed-by: Costin Lupu <costin.lupu@xxxxxxxxx>
On 9/7/19 1:21 PM, Vlad-Andrei BĂDOIU (78692) wrote:
> From: Cristian Banu <cristb@xxxxxxxxx>
>
> This patch implement request and receive functions for the xen 9P
> transport driver.
>
> Signed-off-by: Cristian Banu <cristb@xxxxxxxxx>
> ---
> plat/xen/drivers/9p/9pfront.c | 138 +++++++++++++++++++++++++++++++++-
> 1 file changed, 134 insertions(+), 4 deletions(-)
>
> diff --git a/plat/xen/drivers/9p/9pfront.c b/plat/xen/drivers/9p/9pfront.c
> index 1a8b49c5..a5321898 100644
> --- a/plat/xen/drivers/9p/9pfront.c
> +++ b/plat/xen/drivers/9p/9pfront.c
> @@ -37,6 +37,7 @@
> #include <uk/alloc.h>
> #include <uk/assert.h>
> #include <uk/essentials.h>
> +#include <uk/errptr.h>
> #include <uk/list.h>
> #include <uk/9pdev.h>
> #include <uk/9preq.h>
> @@ -54,10 +55,96 @@ static struct uk_alloc *a;
> static UK_LIST_HEAD(p9front_device_list);
> static DEFINE_SPINLOCK(p9front_device_list_lock);
>
> -static void p9front_handler(evtchn_port_t evtchn __unused,
> +struct p9front_header {
> + uint32_t size;
> + uint8_t type;
> + uint16_t tag;
> +} __packed;
> +
> +static void p9front_recv(struct p9front_dev_ring *ring)
> +{
> + struct p9front_dev *p9fdev = ring->dev;
> + evtchn_port_t evtchn = ring->evtchn;
> + RING_IDX cons, prod, masked_cons, masked_prod;
> + int ring_size, rc;
> + struct p9front_header hdr;
> + struct uk_9preq *req;
> + uint32_t buf_cnt, zc_buf_cnt;
> +
> + ring_size = XEN_FLEX_RING_SIZE(p9fdev->ring_order);
> +
> + while (1) {
> + cons = ring->intf->in_cons;
> + prod = ring->intf->in_prod;
> + xen_rmb();
> +
> + if (xen_9pfs_queued(prod, cons, ring_size) < sizeof(hdr)) {
> + notify_remote_via_evtchn(evtchn);
> + return;
> + }
> +
> + masked_prod = xen_9pfs_mask(prod, ring_size);
> + masked_cons = xen_9pfs_mask(cons, ring_size);
> +
> + xen_9pfs_read_packet(&hdr, ring->data.in, sizeof(hdr),
> + masked_prod, &masked_cons, ring_size);
> +
> + req = uk_9pdev_req_lookup(p9fdev->p9dev, hdr.tag);
> + if (PTRISERR(req)) {
> + uk_pr_warn("Found invalid tag=%u\n", hdr.tag);
> + cons += hdr.size;
> + xen_mb();
> + ring->intf->in_cons = cons;
> + continue;
> + }
> +
> + masked_cons = xen_9pfs_mask(cons, ring_size);
> +
> + /*
> + * Compute amount of data to read into request buffer and into
> + * zero-copy buffer.
> + */
> + buf_cnt = hdr.size;
> + if (hdr.type != UK_9P_RERROR && req->recv.zc_buf)
> + buf_cnt = MIN(buf_cnt, req->recv.zc_offset);
> + zc_buf_cnt = hdr.size - buf_cnt;
> +
> + xen_9pfs_read_packet(req->recv.buf, ring->data.in, buf_cnt,
> + masked_prod, &masked_cons, ring_size);
> + xen_9pfs_read_packet(req->recv.zc_buf, ring->data.in,
> + zc_buf_cnt, masked_prod, &masked_cons,
> + ring_size);
> + cons += hdr.size;
> + xen_mb();
> + ring->intf->in_cons = cons;
> +
> + rc = uk_9preq_receive_cb(req, hdr.size);
> + if (rc)
> + uk_pr_warn("Could not receive reply: %d\n", rc);
> +
> + /* Release reference held by uk_9pdev_req_lookup(). */
> + uk_9preq_put(req);
> + }
> +}
> +
> +static void p9front_handler(evtchn_port_t evtchn,
> struct __regs *regs __unused,
> - void *arg __unused)
> + void *arg)
> {
> + struct p9front_dev_ring *ring = arg;
> +
> + UK_ASSERT(ring);
> + UK_ASSERT(ring->evtchn == evtchn);
> +
> + /*
> + * A new interrupt means that there is a response to be received, which
> + * means that a previously sent request has been removed from the out
> + * ring. Thus, the API can be notified of the possibility of retrying to
> + * send requests blocked on ENOSPC errors.
> + */
> + if (ring->dev->p9dev)
> + uk_9pdev_xmit_notify(ring->dev->p9dev);
> + p9front_recv(ring);
> }
>
> static void p9front_free_dev_ring(struct p9front_dev *p9fdev, int idx)
> @@ -242,9 +329,52 @@ static int p9front_disconnect(struct uk_9pdev *p9dev
> __unused)
> return 0;
> }
>
> -static int p9front_request(struct uk_9pdev *p9dev __unused,
> - struct uk_9preq *req __unused)
> +static int p9front_request(struct uk_9pdev *p9dev,
> + struct uk_9preq *req)
> {
> + struct p9front_dev *p9fdev;
> + struct p9front_dev_ring *ring;
> + int ring_idx, ring_size;
> + RING_IDX masked_prod, masked_cons, prod, cons;
> +
> + UK_ASSERT(p9dev);
> + UK_ASSERT(req);
> + UK_ASSERT(req->state == UK_9PREQ_READY);
> +
> + p9fdev = p9dev->priv;
> +
> + ring_size = XEN_FLEX_RING_SIZE(p9fdev->ring_order);
> +
> + ring_idx = req->tag % p9fdev->nb_rings;
> + ring = &p9fdev->rings[ring_idx];
> +
> + /* Protect against concurrent writes to the out ring. */
> + ukarch_spin_lock(&ring->spinlock);
> + cons = ring->intf->out_cons;
> + prod = ring->intf->out_prod;
> + xen_mb();
> +
> + masked_prod = xen_9pfs_mask(prod, ring_size);
> + masked_cons = xen_9pfs_mask(cons, ring_size);
> +
> + if (ring_size - xen_9pfs_queued(prod, cons, ring_size) <
> + req->xmit.size + req->xmit.zc_size) {
> + ukarch_spin_unlock(&ring->spinlock);
> + return -ENOSPC;
> + }
> +
> + xen_9pfs_write_packet(ring->data.out, req->xmit.buf, req->xmit.size,
> + &masked_prod, masked_cons, ring_size);
> + xen_9pfs_write_packet(ring->data.out, req->xmit.zc_buf,
> req->xmit.zc_size,
> + &masked_prod, masked_cons, ring_size);
> + req->state = UK_9PREQ_SENT;
> + xen_wmb();
> + prod += req->xmit.size + req->xmit.zc_size;
> + ring->intf->out_prod = prod;
> +
> + ukarch_spin_unlock(&ring->spinlock);
> + notify_remote_via_evtchn(ring->evtchn);
> +
> return 0;
> }
>
>
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