Use the common utility function, which contains checks on return values and first calls F_GETFD as recommended by POSIX.1-2001, instead of manually calling fcntl. CID: 1374831 Signed-off-by: Stefano Stabellini <sstabellini@kernel.org> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Greg Kurz <groug@kaod.org> CC: anthony.perard@citrix.com CC: groug@kaod.org CC: aneesh.kumar@linux.vnet.ibm.com CC: Eric Blake <eblake@redhat.com>
443 lines
14 KiB
C
443 lines
14 KiB
C
/*
|
|
* Xen 9p backend
|
|
*
|
|
* Copyright Aporeto 2017
|
|
*
|
|
* Authors:
|
|
* Stefano Stabellini <stefano@aporeto.com>
|
|
*
|
|
*/
|
|
|
|
#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);
|
|
pdu->size = le32_to_cpu(h.size_le);
|
|
pdu->id = h.id;
|
|
pdu->tag = le32_to_cpu(h.tag_le);
|
|
ring->out_size = le32_to_cpu(h.size_le);
|
|
ring->out_cons = cons + le32_to_cpu(h.size_le);
|
|
|
|
qemu_co_queue_init(&pdu->complete);
|
|
pdu_submit(pdu);
|
|
|
|
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,
|
|
};
|