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xenbus_client: Extend interface to support multi-page ring 

Originally Xen PV drivers only use single-page ring to pass along
information. This might limit the throughput between frontend and
backend.

The patch extends Xenbus driver to support multi-page ring, which in
general should improve throughput if ring is the bottleneck. Changes to
various frontend / backend to adapt to the new interface are also
included.

Affected Xen drivers:
* blkfront/back
* netfront/back
* pcifront/back
* scsifront/back
* vtpmfront

The interface is documented, as before, in xenbus_client.c.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Signed-off-by: Bob Liu <bob.liu@oracle.com>
Cc: Konrad Wilk <konrad.wilk@oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
This commit is contained in:
Wei Liu 2015-04-03 14:44:59 +08:00 committed by David Vrabel
parent 278edfc078
commit ccc9d90a9a
11 changed files with 325 additions and 126 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
drivers/block/xen-blkback/xenbus.c
View File

@ -193,7 +193,7 @@ static struct xen_blkif *xen_blkif_alloc(domid_t domid)
return ERR_PTR(-ENOMEM);
}
static int xen_blkif_map(struct xen_blkif *blkif, unsigned long shared_page,
static int xen_blkif_map(struct xen_blkif *blkif, grant_ref_t gref,
unsigned int evtchn)
{
int err;
@ -202,7 +202,8 @@ static int xen_blkif_map(struct xen_blkif *blkif, unsigned long shared_page,
if (blkif->irq)
return 0;
err = xenbus_map_ring_valloc(blkif->be->dev, shared_page, &blkif->blk_ring);
err = xenbus_map_ring_valloc(blkif->be->dev, &gref, 1,
&blkif->blk_ring);
if (err < 0)
return err;

5
drivers/block/xen-blkfront.c
View File

@ -1245,6 +1245,7 @@ static int setup_blkring(struct xenbus_device *dev,
struct blkfront_info *info)
{
struct blkif_sring *sring;
grant_ref_t gref;
int err;
info->ring_ref = GRANT_INVALID_REF;
@ -1257,13 +1258,13 @@ static int setup_blkring(struct xenbus_device *dev,
SHARED_RING_INIT(sring);
FRONT_RING_INIT(&info->ring, sring, PAGE_SIZE);
err = xenbus_grant_ring(dev, virt_to_mfn(info->ring.sring));
err = xenbus_grant_ring(dev, info->ring.sring, 1, &gref);
if (err < 0) {
free_page((unsigned long)sring);
info->ring.sring = NULL;
goto fail;
}
info->ring_ref = err;
info->ring_ref = gref;
err = xenbus_alloc_evtchn(dev, &info->evtchn);
if (err)

5
drivers/char/tpm/xen-tpmfront.c
View File

@ -193,6 +193,7 @@ static int setup_ring(struct xenbus_device *dev, struct tpm_private *priv)
struct xenbus_transaction xbt;
const char *message = NULL;
int rv;
grant_ref_t gref;
priv->shr = (void *)__get_free_page(GFP_KERNEL|__GFP_ZERO);
if (!priv->shr) {
@ -200,11 +201,11 @@ static int setup_ring(struct xenbus_device *dev, struct tpm_private *priv)
return -ENOMEM;
}
rv = xenbus_grant_ring(dev, virt_to_mfn(priv->shr));
rv = xenbus_grant_ring(dev, &priv->shr, 1, &gref);
if (rv < 0)
return rv;
priv->ring_ref = rv;
priv->ring_ref = gref;
rv = xenbus_alloc_evtchn(dev, &priv->evtchn);
if (rv)

4
drivers/net/xen-netback/netback.c
View File

@ -1781,7 +1781,7 @@ int xenvif_map_frontend_rings(struct xenvif_queue *queue,
int err = -ENOMEM;
err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(queue->vif),
tx_ring_ref, &addr);
&tx_ring_ref, 1, &addr);
if (err)
goto err;
@ -1789,7 +1789,7 @@ int xenvif_map_frontend_rings(struct xenvif_queue *queue,
BACK_RING_INIT(&queue->tx, txs, PAGE_SIZE);
err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(queue->vif),
rx_ring_ref, &addr);
&rx_ring_ref, 1, &addr);
if (err)
goto err;

9
drivers/net/xen-netfront.c
View File

@ -1486,6 +1486,7 @@ static int setup_netfront(struct xenbus_device *dev,
{
struct xen_netif_tx_sring *txs;
struct xen_netif_rx_sring *rxs;
grant_ref_t gref;
int err;
queue->tx_ring_ref = GRANT_INVALID_REF;
@ -1502,10 +1503,10 @@ static int setup_netfront(struct xenbus_device *dev,
SHARED_RING_INIT(txs);
FRONT_RING_INIT(&queue->tx, txs, PAGE_SIZE);
err = xenbus_grant_ring(dev, virt_to_mfn(txs));
err = xenbus_grant_ring(dev, txs, 1, &gref);
if (err < 0)
goto grant_tx_ring_fail;
queue->tx_ring_ref = err;
queue->tx_ring_ref = gref;
rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
if (!rxs) {
@ -1516,10 +1517,10 @@ static int setup_netfront(struct xenbus_device *dev,
SHARED_RING_INIT(rxs);
FRONT_RING_INIT(&queue->rx, rxs, PAGE_SIZE);
err = xenbus_grant_ring(dev, virt_to_mfn(rxs));
err = xenbus_grant_ring(dev, rxs, 1, &gref);
if (err < 0)
goto grant_rx_ring_fail;
queue->rx_ring_ref = err;
queue->rx_ring_ref = gref;
if (feature_split_evtchn)
err = setup_netfront_split(queue);

5
drivers/pci/xen-pcifront.c
View File

@ -777,12 +777,13 @@ static int pcifront_publish_info(struct pcifront_device *pdev)
{
int err = 0;
struct xenbus_transaction trans;
grant_ref_t gref;
err = xenbus_grant_ring(pdev->xdev, virt_to_mfn(pdev->sh_info));
err = xenbus_grant_ring(pdev->xdev, pdev->sh_info, 1, &gref);
if (err < 0)
goto out;
pdev->gnt_ref = err;
pdev->gnt_ref = gref;
err = xenbus_alloc_evtchn(pdev->xdev, &pdev->evtchn);
if (err)

5
drivers/scsi/xen-scsifront.c
View File

@ -714,6 +714,7 @@ static int scsifront_alloc_ring(struct vscsifrnt_info *info)
{
struct xenbus_device *dev = info->dev;
struct vscsiif_sring *sring;
grant_ref_t gref;
int err = -ENOMEM;
/***** Frontend to Backend ring start *****/
@ -726,14 +727,14 @@ static int scsifront_alloc_ring(struct vscsifrnt_info *info)
SHARED_RING_INIT(sring);
FRONT_RING_INIT(&info->ring, sring, PAGE_SIZE);
err = xenbus_grant_ring(dev, virt_to_mfn(sring));
err = xenbus_grant_ring(dev, sring, 1, &gref);
if (err < 0) {
free_page((unsigned long)sring);
xenbus_dev_fatal(dev, err,
"fail to grant shared ring (Front to Back)");
return err;
}
info->ring_ref = err;
info->ring_ref = gref;
err = xenbus_alloc_evtchn(dev, &info->evtchn);
if (err) {

2
drivers/xen/xen-pciback/xenbus.c
View File

@ -113,7 +113,7 @@ static int xen_pcibk_do_attach(struct xen_pcibk_device *pdev, int gnt_ref,
"Attaching to frontend resources - gnt_ref=%d evtchn=%d\n",
gnt_ref, remote_evtchn);
err = xenbus_map_ring_valloc(pdev->xdev, gnt_ref, &vaddr);
err = xenbus_map_ring_valloc(pdev->xdev, &gnt_ref, 1, &vaddr);
if (err < 0) {
xenbus_dev_fatal(pdev->xdev, err,
"Error mapping other domain page in ours.");

2
drivers/xen/xen-scsiback.c
View File

@ -809,7 +809,7 @@ static int scsiback_init_sring(struct vscsibk_info *info, grant_ref_t ring_ref,
if (info->irq)
return -1;
err = xenbus_map_ring_valloc(info->dev, ring_ref, &area);
err = xenbus_map_ring_valloc(info->dev, &ring_ref, 1, &area);
if (err)
return err;

389
drivers/xen/xenbus/xenbus_client.c
View File

@ -52,17 +52,25 @@
struct xenbus_map_node {
struct list_head next;
union {
struct vm_struct *area; /* PV */
struct page *page; /* HVM */
struct {
struct vm_struct *area;
} pv;
struct {
struct page *pages[XENBUS_MAX_RING_PAGES];
void *addr;
} hvm;
};
grant_handle_t handle;
grant_handle_t handles[XENBUS_MAX_RING_PAGES];
unsigned int nr_handles;
};
static DEFINE_SPINLOCK(xenbus_valloc_lock);
static LIST_HEAD(xenbus_valloc_pages);
struct xenbus_ring_ops {
int (*map)(struct xenbus_device *dev, int gnt, void **vaddr);
int (*map)(struct xenbus_device *dev,
grant_ref_t *gnt_refs, unsigned int nr_grefs,
void **vaddr);
int (*unmap)(struct xenbus_device *dev, void *vaddr);
};
@ -355,17 +363,39 @@ static void xenbus_switch_fatal(struct xenbus_device *dev, int depth, int err,
/**
* xenbus_grant_ring
* @dev: xenbus device
* @ring_mfn: mfn of ring to grant
* Grant access to the given @ring_mfn to the peer of the given device. Return
* a grant reference on success, or -errno on error. On error, the device will
* switch to XenbusStateClosing, and the error will be saved in the store.
* @vaddr: starting virtual address of the ring
* @nr_pages: number of pages to be granted
* @grefs: grant reference array to be filled in
*
* Grant access to the given @vaddr to the peer of the given device.
* Then fill in @grefs with grant references. Return 0 on success, or
* -errno on error. On error, the device will switch to
* XenbusStateClosing, and the error will be saved in the store.
*/
int xenbus_grant_ring(struct xenbus_device *dev, unsigned long ring_mfn)
int xenbus_grant_ring(struct xenbus_device *dev, void *vaddr,
unsigned int nr_pages, grant_ref_t *grefs)
{
int err = gnttab_grant_foreign_access(dev->otherend_id, ring_mfn, 0);
if (err < 0)
xenbus_dev_fatal(dev, err, "granting access to ring page");
int err;
int i, j;
for (i = 0; i < nr_pages; i++) {
unsigned long addr = (unsigned long)vaddr +
(PAGE_SIZE * i);
err = gnttab_grant_foreign_access(dev->otherend_id,
virt_to_mfn(addr), 0);
if (err < 0) {
xenbus_dev_fatal(dev, err,
"granting access to ring page");
goto fail;
}
grefs[i] = err;
}
return 0;
fail:
for (j = 0; j < i; j++)
gnttab_end_foreign_access_ref(grefs[j], 0);
return err;
}
EXPORT_SYMBOL_GPL(xenbus_grant_ring);
@ -419,62 +449,130 @@ EXPORT_SYMBOL_GPL(xenbus_free_evtchn);
/**
* xenbus_map_ring_valloc
* @dev: xenbus device
* @gnt_ref: grant reference
* @gnt_refs: grant reference array
* @nr_grefs: number of grant references
* @vaddr: pointer to address to be filled out by mapping
*
* Based on Rusty Russell's skeleton driver's map_page.
* Map a page of memory into this domain from another domain's grant table.
* xenbus_map_ring_valloc allocates a page of virtual address space, maps the
* page to that address, and sets *vaddr to that address.
* Returns 0 on success, and GNTST_* (see xen/include/interface/grant_table.h)
* or -ENOMEM on error. If an error is returned, device will switch to
* Map @nr_grefs pages of memory into this domain from another
* domain's grant table. xenbus_map_ring_valloc allocates @nr_grefs
* pages of virtual address space, maps the pages to that address, and
* sets *vaddr to that address. Returns 0 on success, and GNTST_*
* (see xen/include/interface/grant_table.h) or -ENOMEM / -EINVAL on
* error. If an error is returned, device will switch to
* XenbusStateClosing and the error message will be saved in XenStore.
*/
int xenbus_map_ring_valloc(struct xenbus_device *dev, int gnt_ref, void **vaddr)
int xenbus_map_ring_valloc(struct xenbus_device *dev, grant_ref_t *gnt_refs,
unsigned int nr_grefs, void **vaddr)
{
return ring_ops->map(dev, gnt_ref, vaddr);
return ring_ops->map(dev, gnt_refs, nr_grefs, vaddr);
}
EXPORT_SYMBOL_GPL(xenbus_map_ring_valloc);
static int xenbus_map_ring_valloc_pv(struct xenbus_device *dev,
int gnt_ref, void **vaddr)
/* N.B. sizeof(phys_addr_t) doesn't always equal to sizeof(unsigned
* long), e.g. 32-on-64. Caller is responsible for preparing the
* right array to feed into this function */
static int __xenbus_map_ring(struct xenbus_device *dev,
grant_ref_t *gnt_refs,
unsigned int nr_grefs,
grant_handle_t *handles,
phys_addr_t *addrs,
unsigned int flags,
bool *leaked)
{
struct gnttab_map_grant_ref map[XENBUS_MAX_RING_PAGES];
struct gnttab_unmap_grant_ref unmap[XENBUS_MAX_RING_PAGES];
int i, j;
int err = GNTST_okay;
if (nr_grefs > XENBUS_MAX_RING_PAGES)
return -EINVAL;
for (i = 0; i < nr_grefs; i++) {
memset(&map[i], 0, sizeof(map[i]));
gnttab_set_map_op(&map[i], addrs[i], flags, gnt_refs[i],
dev->otherend_id);
handles[i] = INVALID_GRANT_HANDLE;
}
gnttab_batch_map(map, i);
for (i = 0; i < nr_grefs; i++) {
if (map[i].status != GNTST_okay) {
err = map[i].status;
xenbus_dev_fatal(dev, map[i].status,
"mapping in shared page %d from domain %d",
gnt_refs[i], dev->otherend_id);
goto fail;
} else
handles[i] = map[i].handle;
}
return GNTST_okay;
fail:
for (i = j = 0; i < nr_grefs; i++) {
if (handles[i] != INVALID_GRANT_HANDLE) {
memset(&unmap[j], 0, sizeof(unmap[j]));
gnttab_set_unmap_op(&unmap[j], (phys_addr_t)addrs[i],
GNTMAP_host_map, handles[i]);
j++;
}
}
if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap, j))
BUG();
*leaked = false;
for (i = 0; i < j; i++) {
if (unmap[i].status != GNTST_okay) {
*leaked = true;
break;
}
}
return err;
}
static int xenbus_map_ring_valloc_pv(struct xenbus_device *dev,
grant_ref_t *gnt_refs,
unsigned int nr_grefs,
void **vaddr)
{
struct gnttab_map_grant_ref op = {
.flags = GNTMAP_host_map | GNTMAP_contains_pte,
.ref = gnt_ref,
.dom = dev->otherend_id,
};
struct xenbus_map_node *node;
struct vm_struct *area;
pte_t *pte;
pte_t *ptes[XENBUS_MAX_RING_PAGES];
phys_addr_t phys_addrs[XENBUS_MAX_RING_PAGES];
int err = GNTST_okay;
int i;
bool leaked;
*vaddr = NULL;
if (nr_grefs > XENBUS_MAX_RING_PAGES)
return -EINVAL;
node = kzalloc(sizeof(*node), GFP_KERNEL);
if (!node)
return -ENOMEM;
area = alloc_vm_area(PAGE_SIZE, &pte);
area = alloc_vm_area(PAGE_SIZE * nr_grefs, ptes);
if (!area) {
kfree(node);
return -ENOMEM;
}
op.host_addr = arbitrary_virt_to_machine(pte).maddr;
for (i = 0; i < nr_grefs; i++)
phys_addrs[i] = arbitrary_virt_to_machine(ptes[i]).maddr;
gnttab_batch_map(&op, 1);
err = __xenbus_map_ring(dev, gnt_refs, nr_grefs, node->handles,
phys_addrs,
GNTMAP_host_map | GNTMAP_contains_pte,
&leaked);
if (err)
goto failed;
if (op.status != GNTST_okay) {
free_vm_area(area);
kfree(node);
xenbus_dev_fatal(dev, op.status,
"mapping in shared page %d from domain %d",
gnt_ref, dev->otherend_id);
return op.status;
}
node->handle = op.handle;
node->area = area;
node->nr_handles = nr_grefs;
node->pv.area = area;
spin_lock(&xenbus_valloc_lock);
list_add(&node->next, &xenbus_valloc_pages);
@ -482,14 +580,33 @@ static int xenbus_map_ring_valloc_pv(struct xenbus_device *dev,
*vaddr = area->addr;
return 0;
failed:
if (!leaked)
free_vm_area(area);
else
pr_alert("leaking VM area %p size %u page(s)", area, nr_grefs);
kfree(node);
return err;
}
static int xenbus_map_ring_valloc_hvm(struct xenbus_device *dev,
int gnt_ref, void **vaddr)
grant_ref_t *gnt_ref,
unsigned int nr_grefs,
void **vaddr)
{
struct xenbus_map_node *node;
int i;
int err;
void *addr;
bool leaked = false;
/* Why do we need two arrays? See comment of __xenbus_map_ring */
phys_addr_t phys_addrs[XENBUS_MAX_RING_PAGES];
unsigned long addrs[XENBUS_MAX_RING_PAGES];
if (nr_grefs > XENBUS_MAX_RING_PAGES)
return -EINVAL;
*vaddr = NULL;
@ -497,15 +614,32 @@ static int xenbus_map_ring_valloc_hvm(struct xenbus_device *dev,
if (!node)
return -ENOMEM;
err = alloc_xenballooned_pages(1, &node->page, false /* lowmem */);
err = alloc_xenballooned_pages(nr_grefs, node->hvm.pages,
false /* lowmem */);
if (err)
goto out_err;
addr = pfn_to_kaddr(page_to_pfn(node->page));
for (i = 0; i < nr_grefs; i++) {
unsigned long pfn = page_to_pfn(node->hvm.pages[i]);
phys_addrs[i] = (unsigned long)pfn_to_kaddr(pfn);
addrs[i] = (unsigned long)pfn_to_kaddr(pfn);
}
err = __xenbus_map_ring(dev, gnt_ref, nr_grefs, node->handles,
phys_addrs, GNTMAP_host_map, &leaked);
node->nr_handles = nr_grefs;
err = xenbus_map_ring(dev, gnt_ref, &node->handle, addr);
if (err)
goto out_err_free_ballooned_pages;
goto out_free_ballooned_pages;
addr = vmap(node->hvm.pages, nr_grefs, VM_MAP | VM_IOREMAP,
PAGE_KERNEL);
if (!addr) {
err = -ENOMEM;
goto out_xenbus_unmap_ring;
}
node->hvm.addr = addr;
spin_lock(&xenbus_valloc_lock);
list_add(&node->next, &xenbus_valloc_pages);
@ -514,8 +648,16 @@ static int xenbus_map_ring_valloc_hvm(struct xenbus_device *dev,
*vaddr = addr;
return 0;
out_err_free_ballooned_pages:
free_xenballooned_pages(1, &node->page);
out_xenbus_unmap_ring:
if (!leaked)
xenbus_unmap_ring(dev, node->handles, node->nr_handles,
addrs);
else
pr_alert("leaking %p size %u page(s)",
addr, nr_grefs);
out_free_ballooned_pages:
if (!leaked)
free_xenballooned_pages(nr_grefs, node->hvm.pages);
out_err:
kfree(node);
return err;
@ -525,35 +667,37 @@ static int xenbus_map_ring_valloc_hvm(struct xenbus_device *dev,
/**
* xenbus_map_ring
* @dev: xenbus device
* @gnt_ref: grant reference
* @handle: pointer to grant handle to be filled
* @vaddr: address to be mapped to
* @gnt_refs: grant reference array
* @nr_grefs: number of grant reference
* @handles: pointer to grant handle to be filled
* @vaddrs: addresses to be mapped to
* @leaked: fail to clean up a failed map, caller should not free vaddr
*
* Map a page of memory into this domain from another domain's grant table.
* Map pages of memory into this domain from another domain's grant table.
* xenbus_map_ring does not allocate the virtual address space (you must do
* this yourself!). It only maps in the page to the specified address.
* this yourself!). It only maps in the pages to the specified address.
* Returns 0 on success, and GNTST_* (see xen/include/interface/grant_table.h)
* or -ENOMEM on error. If an error is returned, device will switch to
* XenbusStateClosing and the error message will be saved in XenStore.
* or -ENOMEM / -EINVAL on error. If an error is returned, device will switch to
* XenbusStateClosing and the first error message will be saved in XenStore.
* Further more if we fail to map the ring, caller should check @leaked.
* If @leaked is not zero it means xenbus_map_ring fails to clean up, caller
* should not free the address space of @vaddr.
*/
int xenbus_map_ring(struct xenbus_device *dev, int gnt_ref,
grant_handle_t *handle, void *vaddr)
int xenbus_map_ring(struct xenbus_device *dev, grant_ref_t *gnt_refs,
unsigned int nr_grefs, grant_handle_t *handles,
unsigned long *vaddrs, bool *leaked)
{
struct gnttab_map_grant_ref op;
phys_addr_t phys_addrs[XENBUS_MAX_RING_PAGES];
int i;
gnttab_set_map_op(&op, (unsigned long)vaddr, GNTMAP_host_map, gnt_ref,
dev->otherend_id);
if (nr_grefs > XENBUS_MAX_RING_PAGES)
return -EINVAL;
gnttab_batch_map(&op, 1);
for (i = 0; i < nr_grefs; i++)
phys_addrs[i] = (unsigned long)vaddrs[i];
if (op.status != GNTST_okay) {
xenbus_dev_fatal(dev, op.status,
"mapping in shared page %d from domain %d",
gnt_ref, dev->otherend_id);
} else
*handle = op.handle;
return op.status;
return __xenbus_map_ring(dev, gnt_refs, nr_grefs, handles,
phys_addrs, GNTMAP_host_map, leaked);
}
EXPORT_SYMBOL_GPL(xenbus_map_ring);
@ -579,14 +723,15 @@ EXPORT_SYMBOL_GPL(xenbus_unmap_ring_vfree);
static int xenbus_unmap_ring_vfree_pv(struct xenbus_device *dev, void *vaddr)
{
struct xenbus_map_node *node;
struct gnttab_unmap_grant_ref op = {
.host_addr = (unsigned long)vaddr,
};
struct gnttab_unmap_grant_ref unmap[XENBUS_MAX_RING_PAGES];
unsigned int level;
int i;
bool leaked = false;
int err;
spin_lock(&xenbus_valloc_lock);
list_for_each_entry(node, &xenbus_valloc_pages, next) {
if (node->area->addr == vaddr) {
if (node->pv.area->addr == vaddr) {
list_del(&node->next);
goto found;
}
@ -601,22 +746,41 @@ static int xenbus_unmap_ring_vfree_pv(struct xenbus_device *dev, void *vaddr)
return GNTST_bad_virt_addr;
}
op.handle = node->handle;
op.host_addr = arbitrary_virt_to_machine(
lookup_address((unsigned long)vaddr, &level)).maddr;
for (i = 0; i < node->nr_handles; i++) {
unsigned long addr;
if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, &op, 1))
memset(&unmap[i], 0, sizeof(unmap[i]));
addr = (unsigned long)vaddr + (PAGE_SIZE * i);
unmap[i].host_addr = arbitrary_virt_to_machine(
lookup_address(addr, &level)).maddr;
unmap[i].dev_bus_addr = 0;
unmap[i].handle = node->handles[i];
}
if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap, i))
BUG();
if (op.status == GNTST_okay)
free_vm_area(node->area);
err = GNTST_okay;
leaked = false;
for (i = 0; i < node->nr_handles; i++) {
if (unmap[i].status != GNTST_okay) {
leaked = true;
xenbus_dev_error(dev, unmap[i].status,
"unmapping page at handle %d error %d",
node->handles[i], unmap[i].status);
err = unmap[i].status;
break;
}
}
if (!leaked)
free_vm_area(node->pv.area);
else
xenbus_dev_error(dev, op.status,
"unmapping page at handle %d error %d",
node->handle, op.status);
pr_alert("leaking VM area %p size %u page(s)",
node->pv.area, node->nr_handles);
kfree(node);
return op.status;
return err;
}
static int xenbus_unmap_ring_vfree_hvm(struct xenbus_device *dev, void *vaddr)
@ -624,10 +788,12 @@ static int xenbus_unmap_ring_vfree_hvm(struct xenbus_device *dev, void *vaddr)
int rv;
struct xenbus_map_node *node;
void *addr;
unsigned long addrs[XENBUS_MAX_RING_PAGES];
int i;
spin_lock(&xenbus_valloc_lock);
list_for_each_entry(node, &xenbus_valloc_pages, next) {
addr = pfn_to_kaddr(page_to_pfn(node->page));
addr = node->hvm.addr;
if (addr == vaddr) {
list_del(&node->next);
goto found;
@ -643,12 +809,16 @@ static int xenbus_unmap_ring_vfree_hvm(struct xenbus_device *dev, void *vaddr)
return GNTST_bad_virt_addr;
}
rv = xenbus_unmap_ring(dev, node->handle, addr);
for (i = 0; i < node->nr_handles; i++)
addrs[i] = (unsigned long)pfn_to_kaddr(page_to_pfn(node->hvm.pages[i]));
rv = xenbus_unmap_ring(dev, node->handles, node->nr_handles,
addrs);
if (!rv)
free_xenballooned_pages(1, &node->page);
vunmap(vaddr);
else
WARN(1, "Leaking %p\n", vaddr);
WARN(1, "Leaking %p, size %u page(s)\n", vaddr,
node->nr_handles);
kfree(node);
return rv;
@ -657,29 +827,44 @@ static int xenbus_unmap_ring_vfree_hvm(struct xenbus_device *dev, void *vaddr)
/**
* xenbus_unmap_ring
* @dev: xenbus device
* @handle: grant handle
* @vaddr: addr to unmap
* @handles: grant handle array
* @nr_handles: number of handles in the array
* @vaddrs: addresses to unmap
*
* Unmap a page of memory in this domain that was imported from another domain.
* Unmap memory in this domain that was imported from another domain.
* Returns 0 on success and returns GNTST_* on error
* (see xen/include/interface/grant_table.h).
*/
int xenbus_unmap_ring(struct xenbus_device *dev,
grant_handle_t handle, void *vaddr)
grant_handle_t *handles, unsigned int nr_handles,
unsigned long *vaddrs)
{
struct gnttab_unmap_grant_ref op;
struct gnttab_unmap_grant_ref unmap[XENBUS_MAX_RING_PAGES];
int i;
int err;
gnttab_set_unmap_op(&op, (unsigned long)vaddr, GNTMAP_host_map, handle);
if (nr_handles > XENBUS_MAX_RING_PAGES)
return -EINVAL;
if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, &op, 1))
for (i = 0; i < nr_handles; i++)
gnttab_set_unmap_op(&unmap[i], vaddrs[i],
GNTMAP_host_map, handles[i]);
if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap, i))
BUG();
if (op.status != GNTST_okay)
xenbus_dev_error(dev, op.status,
"unmapping page at handle %d error %d",
handle, op.status);
err = GNTST_okay;
for (i = 0; i < nr_handles; i++) {
if (unmap[i].status != GNTST_okay) {
xenbus_dev_error(dev, unmap[i].status,
"unmapping page at handle %d error %d",
handles[i], unmap[i].status);
err = unmap[i].status;
break;
}
}
return op.status;
return err;
}
EXPORT_SYMBOL_GPL(xenbus_unmap_ring);

20
include/xen/xenbus.h
View File

@ -46,6 +46,10 @@
#include <xen/interface/io/xenbus.h>
#include <xen/interface/io/xs_wire.h>
#define XENBUS_MAX_RING_PAGE_ORDER 4
#define XENBUS_MAX_RING_PAGES (1U << XENBUS_MAX_RING_PAGE_ORDER)
#define INVALID_GRANT_HANDLE (~0U)
/* Register callback to watch this node. */
struct xenbus_watch
{
@ -199,15 +203,19 @@ int xenbus_watch_pathfmt(struct xenbus_device *dev, struct xenbus_watch *watch,
const char *pathfmt, ...);
int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state);
int xenbus_grant_ring(struct xenbus_device *dev, unsigned long ring_mfn);
int xenbus_map_ring_valloc(struct xenbus_device *dev,
int gnt_ref, void **vaddr);
int xenbus_map_ring(struct xenbus_device *dev, int gnt_ref,
grant_handle_t *handle, void *vaddr);
int xenbus_grant_ring(struct xenbus_device *dev, void *vaddr,
unsigned int nr_pages, grant_ref_t *grefs);
int xenbus_map_ring_valloc(struct xenbus_device *dev, grant_ref_t *gnt_refs,
unsigned int nr_grefs, void **vaddr);
int xenbus_map_ring(struct xenbus_device *dev,
grant_ref_t *gnt_refs, unsigned int nr_grefs,
grant_handle_t *handles, unsigned long *vaddrs,
bool *leaked);
int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr);
int xenbus_unmap_ring(struct xenbus_device *dev,
grant_handle_t handle, void *vaddr);
grant_handle_t *handles, unsigned int nr_handles,
unsigned long *vaddrs);
int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port);
int xenbus_free_evtchn(struct xenbus_device *dev, int port);