[qemu.git] / hw / 9pfs / xen-9p-backend.c

/*
 * Xen 9p backend
 *
 * Copyright Aporeto 2017
 *
 * Authors:
 *  Stefano Stabellini <[email protected]>
 *
 */

#include "qemu/osdep.h"

#include "hw/hw.h"
#include "hw/9pfs/9p.h"
#include "hw/xen/xen_backend.h"
#include "hw/9pfs/xen-9pfs.h"
#include "qemu/config-file.h"
#include "fsdev/qemu-fsdev.h"

#define VERSIONS "1"
#define MAX_RINGS 8
#define MAX_RING_ORDER 8

typedef struct Xen9pfsRing {
    struct Xen9pfsDev *priv;

    int ref;
    xenevtchn_handle   *evtchndev;
    int evtchn;
    int local_port;
    int ring_order;
    struct xen_9pfs_data_intf *intf;
    unsigned char *data;
    struct xen_9pfs_data ring;

    struct iovec *sg;
    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;
} Xen9pfsRing;

typedef struct Xen9pfsDev {
    struct XenDevice xendev;  /* must be first */
    V9fsState state;
    char *path;
    char *security_model;
    char *tag;
    char *id;

    int num_rings;
    Xen9pfsRing *rings;
} Xen9pfsDev;

static void xen_9pfs_in_sg(Xen9pfsRing *ring,
                           struct iovec *in_sg,
                           int *num,
                           uint32_t idx,
                           uint32_t size)
{
    RING_IDX cons, prod, masked_prod, masked_cons;

    cons = ring->intf->in_cons;
    prod = ring->intf->in_prod;
    xen_rmb();
    masked_prod = xen_9pfs_mask(prod, XEN_FLEX_RING_SIZE(ring->ring_order));
    masked_cons = xen_9pfs_mask(cons, XEN_FLEX_RING_SIZE(ring->ring_order));

    if (masked_prod < masked_cons) {
        in_sg[0].iov_base = ring->ring.in + masked_prod;
        in_sg[0].iov_len = masked_cons - masked_prod;
        *num = 1;
    } else {
        in_sg[0].iov_base = ring->ring.in + masked_prod;
        in_sg[0].iov_len = XEN_FLEX_RING_SIZE(ring->ring_order) - masked_prod;
        in_sg[1].iov_base = ring->ring.in;
        in_sg[1].iov_len = masked_cons;
        *num = 2;
    }
}

static void xen_9pfs_out_sg(Xen9pfsRing *ring,
                            struct iovec *out_sg,
                            int *num,
                            uint32_t idx)
{
    RING_IDX cons, prod, masked_prod, masked_cons;

    cons = ring->intf->out_cons;
    prod = ring->intf->out_prod;
    xen_rmb();
    masked_prod = xen_9pfs_mask(prod, XEN_FLEX_RING_SIZE(ring->ring_order));
    masked_cons = xen_9pfs_mask(cons, XEN_FLEX_RING_SIZE(ring->ring_order));

    if (masked_cons < masked_prod) {
        out_sg[0].iov_base = ring->ring.out + masked_cons;
        out_sg[0].iov_len = ring->out_size;
        *num = 1;
    } else {
        if (ring->out_size >
            (XEN_FLEX_RING_SIZE(ring->ring_order) - masked_cons)) {
            out_sg[0].iov_base = ring->ring.out + masked_cons;
            out_sg[0].iov_len = XEN_FLEX_RING_SIZE(ring->ring_order) -
                                masked_cons;
            out_sg[1].iov_base = ring->ring.out;
            out_sg[1].iov_len = ring->out_size -
                                (XEN_FLEX_RING_SIZE(ring->ring_order) -
                                 masked_cons);
            *num = 2;
        } else {
            out_sg[0].iov_base = ring->ring.out + masked_cons;
            out_sg[0].iov_len = ring->out_size;
            *num = 1;
        }
    }
}

static ssize_t xen_9pfs_pdu_vmarshal(V9fsPDU *pdu,
                                     size_t offset,
                                     const char *fmt,
                                     va_list ap)
{
    Xen9pfsDev *xen_9pfs = container_of(pdu->s, Xen9pfsDev, state);
    struct iovec in_sg[2];
    int num;

    xen_9pfs_in_sg(&xen_9pfs->rings[pdu->tag % xen_9pfs->num_rings],
                   in_sg, &num, pdu->idx, ROUND_UP(offset + 128, 512));
    return v9fs_iov_vmarshal(in_sg, num, offset, 0, fmt, ap);
}

static ssize_t xen_9pfs_pdu_vunmarshal(V9fsPDU *pdu,
                                       size_t offset,
                                       const char *fmt,
                                       va_list ap)
{
    Xen9pfsDev *xen_9pfs = container_of(pdu->s, Xen9pfsDev, state);
    struct iovec out_sg[2];
    int num;

    xen_9pfs_out_sg(&xen_9pfs->rings[pdu->tag % xen_9pfs->num_rings],
                    out_sg, &num, pdu->idx);
    return v9fs_iov_vunmarshal(out_sg, num, offset, 0, fmt, ap);
}

static void xen_9pfs_init_out_iov_from_pdu(V9fsPDU *pdu,
                                           struct iovec **piov,
                                           unsigned int *pniov)
{
    Xen9pfsDev *xen_9pfs = container_of(pdu->s, Xen9pfsDev, state);
    Xen9pfsRing *ring = &xen_9pfs->rings[pdu->tag % xen_9pfs->num_rings];
    int num;

    g_free(ring->sg);

    ring->sg = g_malloc0(sizeof(*ring->sg) * 2);
    xen_9pfs_out_sg(ring, ring->sg, &num, pdu->idx);
    *piov = ring->sg;
    *pniov = num;
}

static void xen_9pfs_init_in_iov_from_pdu(V9fsPDU *pdu,
                                          struct iovec **piov,
                                          unsigned int *pniov,
                                          size_t size)
{
    Xen9pfsDev *xen_9pfs = container_of(pdu->s, Xen9pfsDev, state);
    Xen9pfsRing *ring = &xen_9pfs->rings[pdu->tag % xen_9pfs->num_rings];
    int num;

    g_free(ring->sg);

    ring->sg = g_malloc0(sizeof(*ring->sg) * 2);
    xen_9pfs_in_sg(ring, ring->sg, &num, pdu->idx, size);
    *piov = ring->sg;
    *pniov = num;
}

static void xen_9pfs_push_and_notify(V9fsPDU *pdu)
{
    RING_IDX prod;
    Xen9pfsDev *priv = container_of(pdu->s, Xen9pfsDev, state);
    Xen9pfsRing *ring = &priv->rings[pdu->tag % priv->num_rings];

    g_free(ring->sg);
    ring->sg = NULL;

    ring->intf->out_cons = ring->out_cons;
    xen_wmb();

    prod = ring->intf->in_prod;
    xen_rmb();
    ring->intf->in_prod = prod + pdu->size;
    xen_wmb();

    ring->inprogress = false;
    xenevtchn_notify(ring->evtchndev, ring->local_port);

    qemu_bh_schedule(ring->bh);
}

static const struct V9fsTransport xen_9p_transport = {
    .pdu_vmarshal = xen_9pfs_pdu_vmarshal,
    .pdu_vunmarshal = xen_9pfs_pdu_vunmarshal,
    .init_in_iov_from_pdu = xen_9pfs_init_in_iov_from_pdu,
    .init_out_iov_from_pdu = xen_9pfs_init_out_iov_from_pdu,
    .push_and_notify = xen_9pfs_push_and_notify,
};

static int xen_9pfs_init(struct XenDevice *xendev)
{
    return 0;
}

static int xen_9pfs_receive(Xen9pfsRing *ring)
{
    P9MsgHeader h;
    RING_IDX cons, prod, masked_prod, masked_cons;
    V9fsPDU *pdu;

    if (ring->inprogress) {
        return 0;
    }

    cons = ring->intf->out_cons;
    prod = ring->intf->out_prod;
    xen_rmb();

    if (xen_9pfs_queued(prod, cons, XEN_FLEX_RING_SIZE(ring->ring_order)) <
        sizeof(h)) {
        return 0;
    }
    ring->inprogress = true;

    masked_prod = xen_9pfs_mask(prod, XEN_FLEX_RING_SIZE(ring->ring_order));
    masked_cons = xen_9pfs_mask(cons, XEN_FLEX_RING_SIZE(ring->ring_order));

    xen_9pfs_read_packet((uint8_t *) &h, ring->ring.out, sizeof(h),
                         masked_prod, &masked_cons,
                         XEN_FLEX_RING_SIZE(ring->ring_order));

    /* cannot fail, because we only handle one request per ring at a time */
    pdu = pdu_alloc(&ring->priv->state);
    ring->out_size = le32_to_cpu(h.size_le);
    ring->out_cons = cons + le32_to_cpu(h.size_le);

    pdu_submit(pdu, &h);

    return 0;
}

static void xen_9pfs_bh(void *opaque)
{
    Xen9pfsRing *ring = opaque;
    xen_9pfs_receive(ring);
}

static void xen_9pfs_evtchn_event(void *opaque)
{
    Xen9pfsRing *ring = opaque;
    evtchn_port_t port;

    port = xenevtchn_pending(ring->evtchndev);
    xenevtchn_unmask(ring->evtchndev, port);

    qemu_bh_schedule(ring->bh);
}

static int xen_9pfs_free(struct XenDevice *xendev)
{
    int i;
    Xen9pfsDev *xen_9pdev = container_of(xendev, Xen9pfsDev, xendev);

    g_free(xen_9pdev->id);
    g_free(xen_9pdev->tag);
    g_free(xen_9pdev->path);
    g_free(xen_9pdev->security_model);

    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_9pdev->rings[i].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;
    Xen9pfsDev *xen_9pdev = container_of(xendev, Xen9pfsDev, xendev);
    V9fsState *s = &xen_9pdev->state;
    QemuOpts *fsdev;

    if (xenstore_read_fe_int(&xen_9pdev->xendev, "num-rings",
                             &xen_9pdev->num_rings) == -1 ||
        xen_9pdev->num_rings > MAX_RINGS || xen_9pdev->num_rings < 1) {
        return -1;
    }

    xen_9pdev->rings = g_malloc0(xen_9pdev->num_rings * sizeof(Xen9pfsRing));
    for (i = 0; i < xen_9pdev->num_rings; i++) {
        char *str;
        int ring_order;

        xen_9pdev->rings[i].priv = xen_9pdev;
        xen_9pdev->rings[i].evtchn = -1;
        xen_9pdev->rings[i].local_port = -1;

        str = g_strdup_printf("ring-ref%u", i);
        if (xenstore_read_fe_int(&xen_9pdev->xendev, str,
                                 &xen_9pdev->rings[i].ref) == -1) {
            g_free(str);
            goto out;
        }
        g_free(str);
        str = g_strdup_printf("event-channel-%u", i);
        if (xenstore_read_fe_int(&xen_9pdev->xendev, str,
                                 &xen_9pdev->rings[i].evtchn) == -1) {
            g_free(str);
            goto out;
        }
        g_free(str);

        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;
        }
        ring_order = xen_9pdev->rings[i].intf->ring_order;
        if (ring_order > MAX_RING_ORDER) {
            goto out;
        }
        xen_9pdev->rings[i].ring_order = ring_order;
        xen_9pdev->rings[i].data = xengnttab_map_domain_grant_refs(
                xen_9pdev->xendev.gnttabdev,
                (1 << 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_FLEX_RING_SIZE(ring_order);

        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;
        }
        qemu_set_cloexec(xenevtchn_fd(xen_9pdev->rings[i].evtchndev));
        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]);
    }

    xen_9pdev->security_model = xenstore_read_be_str(xendev, "security_model");
    xen_9pdev->path = xenstore_read_be_str(xendev, "path");
    xen_9pdev->id = s->fsconf.fsdev_id =
        g_strdup_printf("xen9p%d", xendev->dev);
    xen_9pdev->tag = 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", xen_9pdev->path, NULL);
    qemu_opt_set(fsdev, "security_model", xen_9pdev->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. */
}

struct XenDevOps xen_9pfs_ops = {
    .size       = sizeof(Xen9pfsDev),
    .flags      = DEVOPS_FLAG_NEED_GNTDEV,
    .alloc      = xen_9pfs_alloc,
    .init       = xen_9pfs_init,
    .initialise = xen_9pfs_connect,
    .disconnect = xen_9pfs_disconnect,
    .free       = xen_9pfs_free,
};
Commit	Line	Data
b37eeb02 SS	1	/*
	2	* Xen 9p backend
	3	*
	4	* Copyright Aporeto 2017
	5	*
	6	* Authors:
	7	* Stefano Stabellini <[email protected]>
	8	*
	9	*/
	10
	11	#include "qemu/osdep.h"
	12
	13	#include "hw/hw.h"
	14	#include "hw/9pfs/9p.h"
	15	#include "hw/xen/xen_backend.h"
	16	#include "hw/9pfs/xen-9pfs.h"
	17	#include "qemu/config-file.h"
	18	#include "fsdev/qemu-fsdev.h"
	19
f23ef34a SS	20	#define VERSIONS "1"
	21	#define MAX_RINGS 8
	22	#define MAX_RING_ORDER 8
	23
	24	typedef struct Xen9pfsRing {
	25	struct Xen9pfsDev *priv;
	26
	27	int ref;
	28	xenevtchn_handle *evtchndev;
	29	int evtchn;
	30	int local_port;
	31	int ring_order;
	32	struct xen_9pfs_data_intf *intf;
	33	unsigned char *data;
	34	struct xen_9pfs_data ring;
	35
	36	struct iovec *sg;
	37	QEMUBH *bh;
	38
	39	/* local copies, so that we can read/write PDU data directly from
	40	* the ring */
	41	RING_IDX out_cons, out_size, in_cons;
	42	bool inprogress;
	43	} Xen9pfsRing;
	44
b37eeb02 SS	45	typedef struct Xen9pfsDev {
b37eeb02 SS	46	struct XenDevice xendev; /* must be first */
f23ef34a SS	47	V9fsState state;
	48	char *path;
	49	char *security_model;
	50	char *tag;
	51	char *id;
	52
	53	int num_rings;
	54	Xen9pfsRing *rings;
b37eeb02 SS	55	} Xen9pfsDev;
b37eeb02 SS	56
40a23892 SS	57	static void xen_9pfs_in_sg(Xen9pfsRing *ring,
	58	struct iovec *in_sg,
	59	int *num,
	60	uint32_t idx,
	61	uint32_t size)
	62	{
	63	RING_IDX cons, prod, masked_prod, masked_cons;
	64
	65	cons = ring->intf->in_cons;
	66	prod = ring->intf->in_prod;
	67	xen_rmb();
	68	masked_prod = xen_9pfs_mask(prod, XEN_FLEX_RING_SIZE(ring->ring_order));
	69	masked_cons = xen_9pfs_mask(cons, XEN_FLEX_RING_SIZE(ring->ring_order));
	70
	71	if (masked_prod < masked_cons) {
	72	in_sg[0].iov_base = ring->ring.in + masked_prod;
	73	in_sg[0].iov_len = masked_cons - masked_prod;
	74	*num = 1;
	75	} else {
	76	in_sg[0].iov_base = ring->ring.in + masked_prod;
	77	in_sg[0].iov_len = XEN_FLEX_RING_SIZE(ring->ring_order) - masked_prod;
	78	in_sg[1].iov_base = ring->ring.in;
	79	in_sg[1].iov_len = masked_cons;
	80	*num = 2;
	81	}
	82	}
	83
	84	static void xen_9pfs_out_sg(Xen9pfsRing *ring,
	85	struct iovec *out_sg,
	86	int *num,
	87	uint32_t idx)
	88	{
	89	RING_IDX cons, prod, masked_prod, masked_cons;
	90
	91	cons = ring->intf->out_cons;
	92	prod = ring->intf->out_prod;
	93	xen_rmb();
	94	masked_prod = xen_9pfs_mask(prod, XEN_FLEX_RING_SIZE(ring->ring_order));
	95	masked_cons = xen_9pfs_mask(cons, XEN_FLEX_RING_SIZE(ring->ring_order));
	96
	97	if (masked_cons < masked_prod) {
	98	out_sg[0].iov_base = ring->ring.out + masked_cons;
	99	out_sg[0].iov_len = ring->out_size;
	100	*num = 1;
	101	} else {
	102	if (ring->out_size >
	103	(XEN_FLEX_RING_SIZE(ring->ring_order) - masked_cons)) {
	104	out_sg[0].iov_base = ring->ring.out + masked_cons;
	105	out_sg[0].iov_len = XEN_FLEX_RING_SIZE(ring->ring_order) -
	106	masked_cons;
	107	out_sg[1].iov_base = ring->ring.out;
	108	out_sg[1].iov_len = ring->out_size -
	109	(XEN_FLEX_RING_SIZE(ring->ring_order) -
	110	masked_cons);
	111	*num = 2;
	112	} else {
	113	out_sg[0].iov_base = ring->ring.out + masked_cons;
	114	out_sg[0].iov_len = ring->out_size;
	115	*num = 1;
	116	}
	117	}
	118	}
	119
b37eeb02 SS	120	static ssize_t xen_9pfs_pdu_vmarshal(V9fsPDU *pdu,
	121	size_t offset,
	122	const char *fmt,
	123	va_list ap)
	124	{
40a23892 SS	125	Xen9pfsDev *xen_9pfs = container_of(pdu->s, Xen9pfsDev, state);
	126	struct iovec in_sg[2];
	127	int num;
	128
	129	xen_9pfs_in_sg(&xen_9pfs->rings[pdu->tag % xen_9pfs->num_rings],
	130	in_sg, &num, pdu->idx, ROUND_UP(offset + 128, 512));
	131	return v9fs_iov_vmarshal(in_sg, num, offset, 0, fmt, ap);
b37eeb02 SS	132	}
	133
	134	static ssize_t xen_9pfs_pdu_vunmarshal(V9fsPDU *pdu,
	135	size_t offset,
	136	const char *fmt,
	137	va_list ap)
	138	{
40a23892 SS	139	Xen9pfsDev *xen_9pfs = container_of(pdu->s, Xen9pfsDev, state);
	140	struct iovec out_sg[2];
	141	int num;
	142
	143	xen_9pfs_out_sg(&xen_9pfs->rings[pdu->tag % xen_9pfs->num_rings],
	144	out_sg, &num, pdu->idx);
	145	return v9fs_iov_vunmarshal(out_sg, num, offset, 0, fmt, ap);
b37eeb02 SS	146	}
	147
	148	static void xen_9pfs_init_out_iov_from_pdu(V9fsPDU *pdu,
	149	struct iovec **piov,
	150	unsigned int *pniov)
	151	{
40a23892 SS	152	Xen9pfsDev *xen_9pfs = container_of(pdu->s, Xen9pfsDev, state);
	153	Xen9pfsRing *ring = &xen_9pfs->rings[pdu->tag % xen_9pfs->num_rings];
	154	int num;
	155
	156	g_free(ring->sg);
	157
	158	ring->sg = g_malloc0(sizeof(ring->sg) 2);
	159	xen_9pfs_out_sg(ring, ring->sg, &num, pdu->idx);
	160	*piov = ring->sg;
	161	*pniov = num;
b37eeb02 SS	162	}
	163
	164	static void xen_9pfs_init_in_iov_from_pdu(V9fsPDU *pdu,
	165	struct iovec **piov,
	166	unsigned int *pniov,
	167	size_t size)
	168	{
40a23892 SS	169	Xen9pfsDev *xen_9pfs = container_of(pdu->s, Xen9pfsDev, state);
	170	Xen9pfsRing *ring = &xen_9pfs->rings[pdu->tag % xen_9pfs->num_rings];
	171	int num;
	172
	173	g_free(ring->sg);
	174
	175	ring->sg = g_malloc0(sizeof(ring->sg) 2);
	176	xen_9pfs_in_sg(ring, ring->sg, &num, pdu->idx, size);
	177	*piov = ring->sg;
	178	*pniov = num;
b37eeb02 SS	179	}
	180
	181	static void xen_9pfs_push_and_notify(V9fsPDU *pdu)
	182	{
4476e09e SS	183	RING_IDX prod;
	184	Xen9pfsDev *priv = container_of(pdu->s, Xen9pfsDev, state);
	185	Xen9pfsRing *ring = &priv->rings[pdu->tag % priv->num_rings];
	186
	187	g_free(ring->sg);
	188	ring->sg = NULL;
	189
	190	ring->intf->out_cons = ring->out_cons;
	191	xen_wmb();
	192
	193	prod = ring->intf->in_prod;
	194	xen_rmb();
	195	ring->intf->in_prod = prod + pdu->size;
	196	xen_wmb();
	197
	198	ring->inprogress = false;
	199	xenevtchn_notify(ring->evtchndev, ring->local_port);
	200
	201	qemu_bh_schedule(ring->bh);
b37eeb02 SS	202	}
	203
	204	static const struct V9fsTransport xen_9p_transport = {
	205	.pdu_vmarshal = xen_9pfs_pdu_vmarshal,
	206	.pdu_vunmarshal = xen_9pfs_pdu_vunmarshal,
	207	.init_in_iov_from_pdu = xen_9pfs_init_in_iov_from_pdu,
	208	.init_out_iov_from_pdu = xen_9pfs_init_out_iov_from_pdu,
	209	.push_and_notify = xen_9pfs_push_and_notify,
	210	};
	211
	212	static int xen_9pfs_init(struct XenDevice *xendev)
	213	{
	214	return 0;
	215	}
	216
47b70fb1 SS	217	static int xen_9pfs_receive(Xen9pfsRing *ring)
	218	{
	219	P9MsgHeader h;
	220	RING_IDX cons, prod, masked_prod, masked_cons;
	221	V9fsPDU *pdu;
	222
	223	if (ring->inprogress) {
	224	return 0;
	225	}
	226
	227	cons = ring->intf->out_cons;
	228	prod = ring->intf->out_prod;
	229	xen_rmb();
	230
	231	if (xen_9pfs_queued(prod, cons, XEN_FLEX_RING_SIZE(ring->ring_order)) <
	232	sizeof(h)) {
	233	return 0;
	234	}
	235	ring->inprogress = true;
	236
	237	masked_prod = xen_9pfs_mask(prod, XEN_FLEX_RING_SIZE(ring->ring_order));
	238	masked_cons = xen_9pfs_mask(cons, XEN_FLEX_RING_SIZE(ring->ring_order));
	239
	240	xen_9pfs_read_packet((uint8_t *) &h, ring->ring.out, sizeof(h),
	241	masked_prod, &masked_cons,
	242	XEN_FLEX_RING_SIZE(ring->ring_order));
	243
	244	/* cannot fail, because we only handle one request per ring at a time */
	245	pdu = pdu_alloc(&ring->priv->state);
47b70fb1 SS	246	ring->out_size = le32_to_cpu(h.size_le);
	247	ring->out_cons = cons + le32_to_cpu(h.size_le);
	248
506f3275	249	pdu_submit(pdu, &h);
47b70fb1 SS	250
	251	return 0;
	252	}
	253
f23ef34a SS	254	static void xen_9pfs_bh(void *opaque)
f23ef34a SS	255	{
47b70fb1 SS	256	Xen9pfsRing *ring = opaque;
47b70fb1 SS	257	xen_9pfs_receive(ring);
f23ef34a SS	258	}
	259
	260	static void xen_9pfs_evtchn_event(void *opaque)
	261	{
47b70fb1 SS	262	Xen9pfsRing *ring = opaque;
	263	evtchn_port_t port;
	264
	265	port = xenevtchn_pending(ring->evtchndev);
	266	xenevtchn_unmask(ring->evtchndev, port);
	267
	268	qemu_bh_schedule(ring->bh);
f23ef34a SS	269	}
f23ef34a SS	270
b37eeb02 SS	271	static int xen_9pfs_free(struct XenDevice *xendev)
b37eeb02 SS	272	{
f23ef34a SS	273	int i;
	274	Xen9pfsDev *xen_9pdev = container_of(xendev, Xen9pfsDev, xendev);
	275
	276	g_free(xen_9pdev->id);
	277	g_free(xen_9pdev->tag);
	278	g_free(xen_9pdev->path);
	279	g_free(xen_9pdev->security_model);
	280
	281	for (i = 0; i < xen_9pdev->num_rings; i++) {
	282	if (xen_9pdev->rings[i].data != NULL) {
	283	xengnttab_unmap(xen_9pdev->xendev.gnttabdev,
	284	xen_9pdev->rings[i].data,
	285	(1 << xen_9pdev->rings[i].ring_order));
	286	}
	287	if (xen_9pdev->rings[i].intf != NULL) {
	288	xengnttab_unmap(xen_9pdev->xendev.gnttabdev,
	289	xen_9pdev->rings[i].intf,
	290	1);
	291	}
	292	if (xen_9pdev->rings[i].evtchndev > 0) {
	293	qemu_set_fd_handler(xenevtchn_fd(xen_9pdev->rings[i].evtchndev),
	294	NULL, NULL, NULL);
	295	xenevtchn_unbind(xen_9pdev->rings[i].evtchndev,
	296	xen_9pdev->rings[i].local_port);
	297	}
	298	if (xen_9pdev->rings[i].bh != NULL) {
	299	qemu_bh_delete(xen_9pdev->rings[i].bh);
	300	}
	301	}
	302	g_free(xen_9pdev->rings);
	303	return 0;
b37eeb02 SS	304	}
	305
	306	static int xen_9pfs_connect(struct XenDevice *xendev)
	307	{
f23ef34a SS	308	int i;
	309	Xen9pfsDev *xen_9pdev = container_of(xendev, Xen9pfsDev, xendev);
	310	V9fsState *s = &xen_9pdev->state;
	311	QemuOpts *fsdev;
	312
	313	if (xenstore_read_fe_int(&xen_9pdev->xendev, "num-rings",
	314	&xen_9pdev->num_rings) == -1 \|\|
	315	xen_9pdev->num_rings > MAX_RINGS \|\| xen_9pdev->num_rings < 1) {
	316	return -1;
	317	}
	318
	319	xen_9pdev->rings = g_malloc0(xen_9pdev->num_rings * sizeof(Xen9pfsRing));
	320	for (i = 0; i < xen_9pdev->num_rings; i++) {
	321	char *str;
	322	int ring_order;
	323
	324	xen_9pdev->rings[i].priv = xen_9pdev;
	325	xen_9pdev->rings[i].evtchn = -1;
	326	xen_9pdev->rings[i].local_port = -1;
	327
	328	str = g_strdup_printf("ring-ref%u", i);
	329	if (xenstore_read_fe_int(&xen_9pdev->xendev, str,
	330	&xen_9pdev->rings[i].ref) == -1) {
c0c24b95	331	g_free(str);
f23ef34a SS	332	goto out;
	333	}
	334	g_free(str);
	335	str = g_strdup_printf("event-channel-%u", i);
	336	if (xenstore_read_fe_int(&xen_9pdev->xendev, str,
	337	&xen_9pdev->rings[i].evtchn) == -1) {
c0c24b95	338	g_free(str);
f23ef34a SS	339	goto out;
	340	}
	341	g_free(str);
	342
	343	xen_9pdev->rings[i].intf = xengnttab_map_grant_ref(
	344	xen_9pdev->xendev.gnttabdev,
	345	xen_9pdev->xendev.dom,
	346	xen_9pdev->rings[i].ref,
	347	PROT_READ \| PROT_WRITE);
	348	if (!xen_9pdev->rings[i].intf) {
	349	goto out;
	350	}
	351	ring_order = xen_9pdev->rings[i].intf->ring_order;
	352	if (ring_order > MAX_RING_ORDER) {
	353	goto out;
	354	}
	355	xen_9pdev->rings[i].ring_order = ring_order;
	356	xen_9pdev->rings[i].data = xengnttab_map_domain_grant_refs(
	357	xen_9pdev->xendev.gnttabdev,
	358	(1 << ring_order),
	359	xen_9pdev->xendev.dom,
	360	xen_9pdev->rings[i].intf->ref,
	361	PROT_READ \| PROT_WRITE);
	362	if (!xen_9pdev->rings[i].data) {
	363	goto out;
	364	}
	365	xen_9pdev->rings[i].ring.in = xen_9pdev->rings[i].data;
	366	xen_9pdev->rings[i].ring.out = xen_9pdev->rings[i].data +
	367	XEN_FLEX_RING_SIZE(ring_order);
	368
	369	xen_9pdev->rings[i].bh = qemu_bh_new(xen_9pfs_bh, &xen_9pdev->rings[i]);
	370	xen_9pdev->rings[i].out_cons = 0;
	371	xen_9pdev->rings[i].out_size = 0;
	372	xen_9pdev->rings[i].inprogress = false;
	373
	374
	375	xen_9pdev->rings[i].evtchndev = xenevtchn_open(NULL, 0);
	376	if (xen_9pdev->rings[i].evtchndev == NULL) {
	377	goto out;
	378	}
01cd90b6	379	qemu_set_cloexec(xenevtchn_fd(xen_9pdev->rings[i].evtchndev));
f23ef34a SS	380	xen_9pdev->rings[i].local_port = xenevtchn_bind_interdomain
	381	(xen_9pdev->rings[i].evtchndev,
	382	xendev->dom,
	383	xen_9pdev->rings[i].evtchn);
	384	if (xen_9pdev->rings[i].local_port == -1) {
	385	xen_pv_printf(xendev, 0,
	386	"xenevtchn_bind_interdomain failed port=%d\n",
	387	xen_9pdev->rings[i].evtchn);
	388	goto out;
	389	}
	390	xen_pv_printf(xendev, 2, "bind evtchn port %d\n", xendev->local_port);
	391	qemu_set_fd_handler(xenevtchn_fd(xen_9pdev->rings[i].evtchndev),
	392	xen_9pfs_evtchn_event, NULL, &xen_9pdev->rings[i]);
	393	}
	394
	395	xen_9pdev->security_model = xenstore_read_be_str(xendev, "security_model");
	396	xen_9pdev->path = xenstore_read_be_str(xendev, "path");
	397	xen_9pdev->id = s->fsconf.fsdev_id =
	398	g_strdup_printf("xen9p%d", xendev->dev);
	399	xen_9pdev->tag = s->fsconf.tag = xenstore_read_fe_str(xendev, "tag");
	400	v9fs_register_transport(s, &xen_9p_transport);
	401	fsdev = qemu_opts_create(qemu_find_opts("fsdev"),
	402	s->fsconf.tag,
	403	1, NULL);
	404	qemu_opt_set(fsdev, "fsdriver", "local", NULL);
	405	qemu_opt_set(fsdev, "path", xen_9pdev->path, NULL);
	406	qemu_opt_set(fsdev, "security_model", xen_9pdev->security_model, NULL);
	407	qemu_opts_set_id(fsdev, s->fsconf.fsdev_id);
	408	qemu_fsdev_add(fsdev);
	409	v9fs_device_realize_common(s, NULL);
	410
b37eeb02	411	return 0;
f23ef34a SS	412
	413	out:
	414	xen_9pfs_free(xendev);
	415	return -1;
b37eeb02 SS	416	}
	417
	418	static void xen_9pfs_alloc(struct XenDevice *xendev)
	419	{
f23ef34a SS	420	xenstore_write_be_str(xendev, "versions", VERSIONS);
	421	xenstore_write_be_int(xendev, "max-rings", MAX_RINGS);
	422	xenstore_write_be_int(xendev, "max-ring-page-order", MAX_RING_ORDER);
b37eeb02 SS	423	}
	424
	425	static void xen_9pfs_disconnect(struct XenDevice *xendev)
	426	{
f23ef34a	427	/* Dynamic hotplug of PV filesystems at runtime is not supported. */
b37eeb02 SS	428	}
	429
	430	struct XenDevOps xen_9pfs_ops = {
	431	.size = sizeof(Xen9pfsDev),
	432	.flags = DEVOPS_FLAG_NEED_GNTDEV,
	433	.alloc = xen_9pfs_alloc,
	434	.init = xen_9pfs_init,
	435	.initialise = xen_9pfs_connect,
	436	.disconnect = xen_9pfs_disconnect,
	437	.free = xen_9pfs_free,
	438	};