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Re: [Qemu-devel] [PATCH v2 5/9] xen/9pfs: connect to the frontend
From: |
Greg Kurz |
Subject: |
Re: [Qemu-devel] [PATCH v2 5/9] xen/9pfs: connect to the frontend |
Date: |
Wed, 15 Mar 2017 10:48:14 +0100 |
On Mon, 13 Mar 2017 16:55:56 -0700
Stefano Stabellini <address@hidden> wrote:
> Write the limits of the backend to xenstore. Connect to the frontend.
> Upon connection, allocate the rings according to the protocol
> specification.
>
> Initialize a QEMUBH to schedule work upon receiving an event channel
> notification from the frontend.
>
> Signed-off-by: Stefano Stabellini <address@hidden>
> CC: address@hidden
> CC: address@hidden
> CC: Aneesh Kumar K.V <address@hidden>
> CC: Greg Kurz <address@hidden>
> ---
> hw/9pfs/xen-9p-backend.c | 159
> ++++++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 158 insertions(+), 1 deletion(-)
>
> diff --git a/hw/9pfs/xen-9p-backend.c b/hw/9pfs/xen-9p-backend.c
> index 35032d3..0e4a133 100644
> --- a/hw/9pfs/xen-9p-backend.c
> +++ b/hw/9pfs/xen-9p-backend.c
> @@ -17,8 +17,35 @@
> #include "qemu/config-file.h"
> #include "fsdev/qemu-fsdev.h"
>
> +#define VERSIONS "1"
> +#define MAX_RINGS 8
> +#define MAX_RING_ORDER 8
> +
> +struct Xen9pfsRing {
> + struct Xen9pfsDev *priv;
> +
> + int ref;
> + xenevtchn_handle *evtchndev;
> + int evtchn;
> + int local_port;
> + struct xen_9pfs_data_intf *intf;
> + unsigned char *data;
> + struct xen_9pfs_data ring;
> +
> + QEMUBH *bh;
> +
> + /* local copies, so that we can read/write PDU data directly from
> + * the ring */
> + RING_IDX out_cons, out_size, in_cons;
> + bool inprogress;
> +};
> +
QEMU Coding style requires a typedef. FWIW, maybe you could also convert
other structured types like XenDevice or XenDevOps.
> typedef struct Xen9pfsDev {
> struct XenDevice xendev; /* must be first */
> + V9fsState state;
> +
> + int num_rings;
> + struct Xen9pfsRing *rings;
> } Xen9pfsDev;
>
> static ssize_t xen_9pfs_pdu_vmarshal(V9fsPDU *pdu,
> @@ -67,22 +94,152 @@ static int xen_9pfs_init(struct XenDevice *xendev)
> return 0;
> }
>
> +static void xen_9pfs_bh(void *opaque)
> +{
> +}
> +
> +static void xen_9pfs_evtchn_event(void *opaque)
> +{
> +}
> +
> static int xen_9pfs_free(struct XenDevice *xendev)
> {
> - return -1;
> + int i;
> + struct Xen9pfsDev *xen_9pdev = container_of(xendev, struct Xen9pfsDev,
> xendev);
> +
Coding style.
> + for (i = 0; i < xen_9pdev->num_rings; i++) {
> + if (xen_9pdev->rings[i].data != NULL) {
> + xengnttab_unmap(xen_9pdev->xendev.gnttabdev,
> + xen_9pdev->rings[i].data,
> + (1 << XEN_9PFS_RING_ORDER));
> + }
> + if (xen_9pdev->rings[i].intf != NULL) {
> + xengnttab_unmap(xen_9pdev->xendev.gnttabdev,
> + xen_9pdev->rings[i].intf,
> + 1);
> + }
> + if (xen_9pdev->rings[i].evtchndev > 0) {
> + qemu_set_fd_handler(xenevtchn_fd(xen_9pdev->rings[i].evtchndev),
> + NULL, NULL, NULL);
> + xenevtchn_unbind(xen_9pdev->rings[i].evtchndev,
> xen_9pdev->rings[i].local_port);
> + }
> + if (xen_9pdev->rings[i].bh != NULL) {
> + qemu_bh_delete(xen_9pdev->rings[i].bh);
> + }
> + }
> + g_free(xen_9pdev->rings);
> + return 0;
> }
>
> static int xen_9pfs_connect(struct XenDevice *xendev)
> {
> + int i;
> + struct Xen9pfsDev *xen_9pdev = container_of(xendev, struct Xen9pfsDev,
> xendev);
Coding style.
> + V9fsState *s = &xen_9pdev->state;
> + QemuOpts *fsdev;
> + char *security_model, *path;
> +
> + if (xenstore_read_fe_int(&xen_9pdev->xendev, "num-rings",
> + &xen_9pdev->num_rings) == -1 ||
> + xen_9pdev->num_rings > MAX_RINGS) {
> + return -1;
> + }
> +
> + xen_9pdev->rings = g_malloc0(xen_9pdev->num_rings * sizeof(struct
> Xen9pfsRing));
> + for (i = 0; i < xen_9pdev->num_rings; i++) {
> + char str[16];
> +
> + xen_9pdev->rings[i].priv = xen_9pdev;
> + xen_9pdev->rings[i].evtchn = -1;
> + xen_9pdev->rings[i].local_port = -1;
> +
> + sprintf(str, "ring-ref%u", i);
> + if (xenstore_read_fe_int(&xen_9pdev->xendev, str,
> + &xen_9pdev->rings[i].ref) == -1) {
> + goto out;
> + }
> + sprintf(str, "event-channel-%u", i);
> + if (xenstore_read_fe_int(&xen_9pdev->xendev, str,
> + &xen_9pdev->rings[i].evtchn) == -1) {
> + goto out;
> + }
> +
> + xen_9pdev->rings[i].intf = xengnttab_map_grant_ref(
> + xen_9pdev->xendev.gnttabdev,
> + xen_9pdev->xendev.dom,
> + xen_9pdev->rings[i].ref,
> + PROT_READ | PROT_WRITE);
> + if (!xen_9pdev->rings[i].intf) {
> + goto out;
> + }
> + xen_9pdev->rings[i].data = xengnttab_map_domain_grant_refs(
> + xen_9pdev->xendev.gnttabdev,
> + (1 << XEN_9PFS_RING_ORDER),
> + xen_9pdev->xendev.dom,
> + xen_9pdev->rings[i].intf->ref,
> + PROT_READ | PROT_WRITE);
> + if (!xen_9pdev->rings[i].data) {
> + goto out;
> + }
> + xen_9pdev->rings[i].ring.in = xen_9pdev->rings[i].data;
> + xen_9pdev->rings[i].ring.out = xen_9pdev->rings[i].data +
> XEN_9PFS_RING_SIZE;
> +
> + xen_9pdev->rings[i].bh = qemu_bh_new(xen_9pfs_bh,
> &xen_9pdev->rings[i]);
> + xen_9pdev->rings[i].out_cons = 0;
> + xen_9pdev->rings[i].out_size = 0;
> + xen_9pdev->rings[i].inprogress = false;
> +
> +
> + xen_9pdev->rings[i].evtchndev = xenevtchn_open(NULL, 0);
> + if (xen_9pdev->rings[i].evtchndev == NULL) {
> + goto out;
> + }
> + fcntl(xenevtchn_fd(xen_9pdev->rings[i].evtchndev), F_SETFD,
> FD_CLOEXEC);
> + xen_9pdev->rings[i].local_port = xenevtchn_bind_interdomain
> + (xen_9pdev->rings[i].evtchndev, xendev->dom,
> xen_9pdev->rings[i].evtchn);
> + if (xen_9pdev->rings[i].local_port == -1) {
> + xen_pv_printf(xendev, 0, "xenevtchn_bind_interdomain failed
> port=%d\n",
> + xen_9pdev->rings[i].evtchn);
> + goto out;
> + }
> + xen_pv_printf(xendev, 2, "bind evtchn port %d\n",
> xendev->local_port);
> + qemu_set_fd_handler(xenevtchn_fd(xen_9pdev->rings[i].evtchndev),
> + xen_9pfs_evtchn_event, NULL, &xen_9pdev->rings[i]);
> + }
> +
> + security_model = xenstore_read_be_str(xendev, "security_model");
> + path = xenstore_read_be_str(xendev, "path");
> + s->fsconf.fsdev_id = g_malloc(strlen("xen9p") + 6);
> + sprintf(s->fsconf.fsdev_id, "xen9p%d", xendev->dev);
Please use g_strdup_printf().
> + s->fsconf.tag = xenstore_read_fe_str(xendev, "tag");
> + v9fs_register_transport(s, &xen_9p_transport);
> + fsdev = qemu_opts_create(qemu_find_opts("fsdev"),
> + s->fsconf.tag,
> + 1, NULL);
> + qemu_opt_set(fsdev, "fsdriver", "local", NULL);
> + qemu_opt_set(fsdev, "path", path, NULL);
> + qemu_opt_set(fsdev, "security_model", security_model, NULL);
> + qemu_opts_set_id(fsdev, s->fsconf.fsdev_id);
> + qemu_fsdev_add(fsdev);
> + v9fs_device_realize_common(s, NULL);
> +
> return 0;
> +
> +out:
> + xen_9pfs_free(xendev);
> + return -1;
> }
>
> static void xen_9pfs_alloc(struct XenDevice *xendev)
> {
> + xenstore_write_be_str(xendev, "versions", VERSIONS);
> + xenstore_write_be_int(xendev, "max-rings", MAX_RINGS);
> + xenstore_write_be_int(xendev, "max-ring-page-order", MAX_RING_ORDER);
> }
>
> static void xen_9pfs_disconnect(struct XenDevice *xendev)
> {
> + /* Dynamic hotplug of PV filesystems at runtime is not supported. */
Does this mean that this function is never called ? Or that it should
report an error ? Or print one ?
In any case, it looks weird that it doesn't free the fsdev_id that
was allocated in xen_9pfs_connect().
> }
>
> struct XenDevOps xen_9pfs_ops = {
pgpcgAuwMFLbW.pgp
Description: OpenPGP digital signature
- Re: [Qemu-devel] [PATCH v2 2/9] xen: import ring.h from xen, (continued)
[Qemu-devel] [PATCH v2 4/9] xen/9pfs: introduce Xen 9pfs backend, Stefano Stabellini, 2017/03/13
[Qemu-devel] [PATCH v2 5/9] xen/9pfs: connect to the frontend, Stefano Stabellini, 2017/03/13
Re: [Qemu-devel] [PATCH v2 5/9] xen/9pfs: connect to the frontend,
Greg Kurz <=
Re: [Qemu-devel] [PATCH v2 5/9] xen/9pfs: connect to the frontend, Stefano Stabellini, 2017/03/15
[Qemu-devel] [PATCH v2 7/9] xen/9pfs: implement in/out_iov_from_pdu and vmarshal/vunmarshal, Stefano Stabellini, 2017/03/13
[Qemu-devel] [PATCH v2 9/9] xen/9pfs: build and register Xen 9pfs backend, Stefano Stabellini, 2017/03/13
[Qemu-devel] [PATCH v2 6/9] xen/9pfs: receive requests from the frontend, Stefano Stabellini, 2017/03/13
Re: [Qemu-devel] [PATCH v2 6/9] xen/9pfs: receive requests from the frontend, Greg Kurz, 2017/03/15
Re: [Qemu-devel] [PATCH v2 6/9] xen/9pfs: receive requests from the frontend, Stefano Stabellini, 2017/03/15