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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH 2 of 2] xenpaging: handle GNTST_eagain in kernel drivers
On Fri, Dec 02, 2011 at 07:27:20AM -0800, Andres Lagar-Cavilla wrote:
> > On Thu, Dec 01, 2011 at 03:51:55PM -0500, Andres Lagar-Cavilla wrote:
> >> drivers/xen/blkback/blkback.c | 6 ++-
> >> drivers/xen/blkback/interface.c | 9 +++-
> >> drivers/xen/core/gnttab.c | 4 +-
> >> drivers/xen/gntdev/gntdev.c | 49
> >> +++++++++++++++++------------
> >> drivers/xen/netback/interface.c | 5 +-
> >> drivers/xen/netback/netback.c | 16 ++++++---
> >> drivers/xen/scsiback/interface.c | 10 +++---
> >> drivers/xen/scsiback/scsiback.c | 4 +-
> >> drivers/xen/tpmback/interface.c | 7 +--
> >> drivers/xen/tpmback/tpmback.c | 20 ++++-------
> >> drivers/xen/usbback/interface.c | 16 ++++----
> >> drivers/xen/usbback/usbback.c | 4 +-
> >> drivers/xen/xenbus/xenbus_backend_client.c | 10 +++---
> >> include/xen/gnttab.h | 37 ++++++++++++++++++++++
> >> 14 files changed, 126 insertions(+), 71 deletions(-)
> >>
> >>
> >> Handle GNTST_eagain status from GNTTABOP_map_grant_ref and
> >> GNTTABOP_copy operations properly to allow usage of xenpaging without
> >> causing crashes or data corruption.
> >>
> >> Replace all relevant HYPERVISOR_grant_table_op() calls with a retry
> >> loop. This loop is implemented as a macro to allow different
> >> GNTTABOP_* args. It will sleep up to 33 seconds and wait for the
> >> page to be paged in again.
> >>
> >> All ->status checks were updated to use the GNTST_* namespace. All
> >> return values are converted from GNTST_* namespace to 0/-EINVAL, since
> >> all callers did not use the actual return value.
> >
> > Any plans to do this for the pvops tree?
> Slowly but surely. Working with XCP presently, so pvops is not at the top
> of my stack. Do you want to get at a specific merge window?
Its more of a review concern. Meaning that if you send for the upstream
kernel lots of folks are going to be looking at it. So the patches
will change - which means that the version upstream can be very
different from the one that you have for XCP - so in the end you will
have to deal with two different code-bases to maintain.
That can get a bit difficult to manage.
Granted not all of those drivers are in the upstream kernel so might not
make any difference.
>
> Andres
> >
> >>
> >> Signed-off-by: Olaf Hering <olaf@xxxxxxxxx>
> >> Acked-by: Patrick Colp <pjcolp@xxxxxxxxx>
> >>
> >> This is a port from xenlinux 2.6.18 to the 2.6.32 xcp tree
> >> Signed-off-by: Andres Lagar-Cavilla <andres@xxxxxxxxxxxxxxxx>
> >>
> >> diff -r df9e25a0189b -r 1170bc32db41 drivers/xen/blkback/blkback.c
> >> --- a/drivers/xen/blkback/blkback.c
> >> +++ b/drivers/xen/blkback/blkback.c
> >> @@ -701,11 +701,13 @@ static void dispatch_rw_block_io(blkif_t
> >> BUG_ON(ret);
> >>
> >> for (i = 0; i < nseg; i++) {
> >> - if (unlikely(map[i].status != 0)) {
> >> + if (unlikely(map[i].status == GNTST_eagain))
> >> +
> >> gnttab_check_GNTST_eagain_do_while(GNTTABOP_map_grant_ref, &map[i]);
> >> + if (unlikely(map[i].status != GNTST_okay)) {
> >> DPRINTK("grant map of dom %u gref %u failed: status
> >> %d\n",
> >> blkif->domid, req->seg[i].gref, map[i].status);
> >> map[i].handle = BLKBACK_INVALID_HANDLE;
> >> - ret |= 1;
> >> + ret = 1;
> >> continue;
> >> }
> >>
> >> diff -r df9e25a0189b -r 1170bc32db41 drivers/xen/blkback/interface.c
> >> --- a/drivers/xen/blkback/interface.c
> >> +++ b/drivers/xen/blkback/interface.c
> >> @@ -95,7 +95,7 @@ static int map_frontend_pages(blkif_t *b
> >> struct vm_struct *area = blkif->blk_ring_area;
> >> struct gnttab_map_grant_ref op[BLKIF_MAX_RING_PAGES];
> >> unsigned int i;
> >> - int status = 0;
> >> + int status = GNTST_okay;
> >>
> >> for (i = 0; i < nr_shared_pages; i++) {
> >> unsigned long addr = (unsigned long)area->addr +
> >> @@ -110,7 +110,10 @@ static int map_frontend_pages(blkif_t *b
> >> BUG();
> >>
> >> for (i = 0; i < nr_shared_pages; i++) {
> >> - if ((status = op[i].status) != 0) {
> >> + if (op[i].status == GNTST_eagain)
> >> +
> >> gnttab_check_GNTST_eagain_do_while(GNTTABOP_map_grant_ref, &op[i]);
> >> + if (op[i].status != GNTST_okay) {
> >> + status = op[i].status;
> >> blkif->shmem_handle[i] = INVALID_GRANT_HANDLE;
> >> continue;
> >> }
> >> @@ -120,7 +123,7 @@ static int map_frontend_pages(blkif_t *b
> >>
> >> blkif->nr_shared_pages = nr_shared_pages;
> >>
> >> - if (status != 0) {
> >> + if (status != GNTST_okay) {
> >> DPRINTK(" Grant table operation failure !\n");
> >> unmap_frontend_pages(blkif);
> >> }
> >> diff -r df9e25a0189b -r 1170bc32db41 drivers/xen/core/gnttab.c
> >> --- a/drivers/xen/core/gnttab.c
> >> +++ b/drivers/xen/core/gnttab.c
> >> @@ -773,7 +773,7 @@ static int gnttab_map(unsigned int start
> >> return -ENOSYS;
> >> }
> >>
> >> - BUG_ON(rc || setup.status);
> >> + BUG_ON(rc || (setup.status != GNTST_okay));
> >>
> >> if (shared.raw == NULL)
> >> shared.raw = arch_gnttab_alloc_shared(gframes);
> >> @@ -901,7 +901,7 @@ int gnttab_copy_grant_page(grant_ref_t r
> >> err = HYPERVISOR_grant_table_op(GNTTABOP_unmap_and_replace,
> >> &unmap, 1);
> >> BUG_ON(err);
> >> - BUG_ON(unmap.status);
> >> + BUG_ON(unmap.status != GNTST_okay);
> >>
> >> write_sequnlock_irq(&gnttab_dma_lock);
> >>
> >> diff -r df9e25a0189b -r 1170bc32db41 drivers/xen/gntdev/gntdev.c
> >> --- a/drivers/xen/gntdev/gntdev.c
> >> +++ b/drivers/xen/gntdev/gntdev.c
> >> @@ -503,7 +503,7 @@ static int gntdev_mmap (struct file *fli
> >> uint64_t ptep;
> >> int ret;
> >> int flags;
> >> - int i;
> >> + int i, exit_ret;
> >> struct page *page;
> >> gntdev_file_private_data_t *private_data = flip->private_data;
> >>
> >> @@ -578,6 +578,7 @@ static int gntdev_mmap (struct file *fli
> >> vma->vm_mm->context.has_foreign_mappings = 1;
> >> #endif
> >>
> >> + exit_ret = -ENOMEM;
> >> for (i = 0; i < size; ++i) {
> >>
> >> flags = GNTMAP_host_map;
> >> @@ -598,14 +599,18 @@ static int gntdev_mmap (struct file *fli
> >> ret = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref,
> >> &op, 1);
> >> BUG_ON(ret);
> >> - if (op.status) {
> >> - printk(KERN_ERR "Error mapping the grant reference "
> >> - "into the kernel (%d). domid = %d; ref = %d\n",
> >> - op.status,
> >> - private_data->grants[slot_index+i]
> >> - .u.valid.domid,
> >> - private_data->grants[slot_index+i]
> >> - .u.valid.ref);
> >> + if (op.status != GNTST_okay) {
> >> + if (op.status != GNTST_eagain)
> >> + printk(KERN_ERR "Error mapping the grant
> >> reference "
> >> + "into the kernel (%d). domid = %d;
> >> ref = %d\n",
> >> + op.status,
> >> + private_data->grants[slot_index+i]
> >> + .u.valid.domid,
> >> + private_data->grants[slot_index+i]
> >> + .u.valid.ref);
> >> + else
> >> + /* Propagate instead of trying to fix it up */
> >> + exit_ret = -EAGAIN;
> >> goto undo_map_out;
> >> }
> >>
> >> @@ -674,14 +679,17 @@ static int gntdev_mmap (struct file *fli
> >> ret = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref,
> >> &op, 1);
> >> BUG_ON(ret);
> >> - if (op.status) {
> >> + if (op.status != GNTST_okay) {
> >> printk(KERN_ERR "Error mapping the grant "
> >> - "reference into user space (%d). domid "
> >> - "= %d; ref = %d\n", op.status,
> >> - private_data->grants[slot_index+i].u
> >> - .valid.domid,
> >> - private_data->grants[slot_index+i].u
> >> - .valid.ref);
> >> + "reference into user space (%d).
> >> domid "
> >> + "= %d; ref = %d\n", op.status,
> >> + private_data->grants[slot_index+i].u
> >> + .valid.domid,
> >> + private_data->grants[slot_index+i].u
> >> + .valid.ref);
> >> + /* GNTST_eagain (i.e. page paged out) sohuld
> >> never happen
> >> + * once we've mapped into kernel space */
> >> + BUG_ON(op.status == GNTST_eagain);
> >> goto undo_map_out;
> >> }
> >>
> >> @@ -705,9 +713,10 @@ static int gntdev_mmap (struct file *fli
> >> }
> >>
> >> }
> >> + exit_ret = 0;
> >>
> >> up_write(&private_data->grants_sem);
> >> - return 0;
> >> + return exit_ret;
> >>
> >> undo_map_out:
> >> /* If we have a mapping failure, the unmapping will be taken care of
> >> @@ -725,7 +734,7 @@ undo_map_out:
> >>
> >> up_write(&private_data->grants_sem);
> >>
> >> - return -ENOMEM;
> >> + return exit_ret;
> >> }
> >>
> >> static pte_t gntdev_clear_pte(struct vm_area_struct *vma, unsigned long
> >> addr,
> >> @@ -777,7 +786,7 @@ static pte_t gntdev_clear_pte(struct vm_
> >> ret = HYPERVISOR_grant_table_op(
> >> GNTTABOP_unmap_grant_ref, &op, 1);
> >> BUG_ON(ret);
> >> - if (op.status)
> >> + if (op.status != GNTST_okay)
> >> printk("User unmap grant status = %d\n",
> >> op.status);
> >> } else {
> >> @@ -794,7 +803,7 @@ static pte_t gntdev_clear_pte(struct vm_
> >> ret = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref,
> >> &op, 1);
> >> BUG_ON(ret);
> >> - if (op.status)
> >> + if (op.status != GNTST_okay)
> >> printk("Kernel unmap grant status = %d\n", op.status);
> >>
> >>
> >> diff -r df9e25a0189b -r 1170bc32db41 drivers/xen/netback/interface.c
> >> --- a/drivers/xen/netback/interface.c
> >> +++ b/drivers/xen/netback/interface.c
> >> @@ -381,10 +381,9 @@ static int map_frontend_pages(struct xen
> >> gnttab_set_map_op(&op, (unsigned long)comms->ring_area->addr,
> >> GNTMAP_host_map, ring_ref, domid);
> >>
> >> - if (HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &op, 1))
> >> - BUG();
> >> + gnttab_check_GNTST_eagain_do_while(GNTTABOP_map_grant_ref, &op);
> >>
> >> - if (op.status) {
> >> + if (op.status != GNTST_okay) {
> >> DPRINTK(" Gnttab failure mapping ring_ref!\n");
> >> free_vm_area(comms->ring_area);
> >> return op.status;
> >> diff -r df9e25a0189b -r 1170bc32db41 drivers/xen/netback/netback.c
> >> --- a/drivers/xen/netback/netback.c
> >> +++ b/drivers/xen/netback/netback.c
> >> @@ -419,11 +419,13 @@ static int netbk_check_gop(int nr_copy_s
> >>
> >> for (i = 0; i < nr_copy_slots; i++) {
> >> copy_op = npo->copy + npo->copy_cons++;
> >> + if (copy_op->status == GNTST_eagain)
> >> + gnttab_check_GNTST_eagain_while(GNTTABOP_copy, copy_op);
> >> if (copy_op->status != GNTST_okay) {
> >> - DPRINTK("Bad status %d from copy to DOM%d.\n",
> >> - copy_op->status, domid);
> >> - status = NETIF_RSP_ERROR;
> >> - }
> >> + DPRINTK("Bad status %d from copy to DOM%d.\n",
> >> + copy_op->status, domid);
> >> + status = NETIF_RSP_ERROR;
> >> + }
> >> }
> >>
> >> return status;
> >> @@ -1020,7 +1022,11 @@ static int netbk_tx_check_mop(struct xen
> >>
> >> /* Check status of header. */
> >> err = mop->status;
> >> - if (unlikely(err)) {
> >> + if (err == GNTST_eagain) {
> >> + gnttab_check_GNTST_eagain_do_while(GNTTABOP_map_grant_ref, mop);
> >> + err = mop->status;
> >> + }
> >> + if (unlikely(err != GNTST_okay)) {
> >> pending_ring_idx_t index;
> >> index = pending_index(netbk->pending_prod++);
> >> txp = &pending_tx_info[pending_idx].req;
> >> diff -r df9e25a0189b -r 1170bc32db41 drivers/xen/scsiback/interface.c
> >> --- a/drivers/xen/scsiback/interface.c
> >> +++ b/drivers/xen/scsiback/interface.c
> >> @@ -69,18 +69,18 @@ static int map_frontend_page( struct vsc
> >> GNTMAP_host_map, ring_ref,
> >> info->domid);
> >>
> >> - err = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &op, 1);
> >> - BUG_ON(err);
> >> + gnttab_check_GNTST_eagain_do_while(GNTTABOP_map_grant_ref, &op);
> >>
> >> - if (op.status) {
> >> - printk(KERN_ERR "scsiback: Grant table operation failure !\n");
> >> + if (op.status != GNTST_okay) {
> >> + printk(KERN_ERR "scsiback: Grant table operation failure %d!\n",
> >> + (int) op.status);
> >> return op.status;
> >> }
> >>
> >> info->shmem_ref = ring_ref;
> >> info->shmem_handle = op.handle;
> >>
> >> - return (GNTST_okay);
> >> + return 0;
> >> }
> >>
> >> static void unmap_frontend_page(struct vscsibk_info *info)
> >> diff -r df9e25a0189b -r 1170bc32db41 drivers/xen/scsiback/scsiback.c
> >> --- a/drivers/xen/scsiback/scsiback.c
> >> +++ b/drivers/xen/scsiback/scsiback.c
> >> @@ -287,7 +287,9 @@ static int scsiback_gnttab_data_map(vscs
> >> for_each_sg (pending_req->sgl, sg, nr_segments, i) {
> >> struct page *pg;
> >>
> >> - if (unlikely(map[i].status != 0)) {
> >> + if (unlikely(map[i].status == GNTST_eagain))
> >> +
> >> gnttab_check_GNTST_eagain_while(GNTTABOP_map_grant_ref, &map[i]);
> >> + if (unlikely(map[i].status != GNTST_okay)) {
> >> printk(KERN_ERR "scsiback: invalid buffer --
> >> could not remap
> >> it\n");
> >> map[i].handle = SCSIBACK_INVALID_HANDLE;
> >> err |= 1;
> >> diff -r df9e25a0189b -r 1170bc32db41 drivers/xen/tpmback/interface.c
> >> --- a/drivers/xen/tpmback/interface.c
> >> +++ b/drivers/xen/tpmback/interface.c
> >> @@ -86,11 +86,10 @@ static int map_frontend_page(tpmif_t *tp
> >> gnttab_set_map_op(&op, (unsigned long)tpmif->tx_area->addr,
> >> GNTMAP_host_map, shared_page, tpmif->domid);
> >>
> >> - if (HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &op, 1))
> >> - BUG();
> >> + gnttab_check_GNTST_eagain_do_while(GNTTABOP_map_grant_ref, &op);
> >>
> >> - if (op.status) {
> >> - DPRINTK(" Grant table operation failure !\n");
> >> + if (op.status != GNTST_okay) {
> >> + DPRINTK(" Grant table operation failure %d!\n", (int)
> >> op.status);
> >> return op.status;
> >> }
> >>
> >> diff -r df9e25a0189b -r 1170bc32db41 drivers/xen/tpmback/tpmback.c
> >> --- a/drivers/xen/tpmback/tpmback.c
> >> +++ b/drivers/xen/tpmback/tpmback.c
> >> @@ -256,15 +256,13 @@ int _packet_write(struct packet *pak,
> >> gnttab_set_map_op(&map_op, idx_to_kaddr(tpmif, i),
> >> GNTMAP_host_map, tx->ref, tpmif->domid);
> >>
> >> - if (unlikely(HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref,
> >> - &map_op, 1))) {
> >> - BUG();
> >> - }
> >> + gnttab_check_GNTST_eagain_do_while(GNTTABOP_map_grant_ref,
> >> &map_op);
> >>
> >> handle = map_op.handle;
> >>
> >> - if (map_op.status) {
> >> - DPRINTK(" Grant table operation failure !\n");
> >> + if (map_op.status != GNTST_okay) {
> >> + DPRINTK(" Grant table operation failure %d!\n",
> >> + (int) map_op.status);
> >> return 0;
> >> }
> >>
> >> @@ -394,13 +392,11 @@ static int packet_read_shmem(struct pack
> >> gnttab_set_map_op(&map_op, idx_to_kaddr(tpmif, i),
> >> GNTMAP_host_map, tx->ref, tpmif->domid);
> >>
> >> - if (unlikely(HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref,
> >> - &map_op, 1))) {
> >> - BUG();
> >> - }
> >> + gnttab_check_GNTST_eagain_do_while(GNTTABOP_map_grant_ref,
> >> &map_op);
> >>
> >> - if (map_op.status) {
> >> - DPRINTK(" Grant table operation failure !\n");
> >> + if (map_op.status != GNTST_okay) {
> >> + DPRINTK(" Grant table operation failure %d!\n",
> >> + (int) map_op.status);
> >> return -EFAULT;
> >> }
> >>
> >> diff -r df9e25a0189b -r 1170bc32db41 drivers/xen/usbback/interface.c
> >> --- a/drivers/xen/usbback/interface.c
> >> +++ b/drivers/xen/usbback/interface.c
> >> @@ -109,11 +109,11 @@ static int map_frontend_pages(usbif_t *u
> >> gnttab_set_map_op(&op, (unsigned long)usbif->urb_ring_area->addr,
> >> GNTMAP_host_map, urb_ring_ref, usbif->domid);
> >>
> >> - if (HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &op, 1))
> >> - BUG();
> >> + gnttab_check_GNTST_eagain_do_while(GNTTABOP_map_grant_ref, &op);
> >>
> >> - if (op.status) {
> >> - printk(KERN_ERR "grant table failure mapping urb_ring_ref\n");
> >> + if (op.status != GNTST_okay) {
> >> + printk(KERN_ERR "grant table failure mapping urb_ring_ref %d\n",
> >> + (int) op.status);
> >> return op.status;
> >> }
> >>
> >> @@ -123,17 +123,17 @@ static int map_frontend_pages(usbif_t *u
> >> gnttab_set_map_op(&op, (unsigned long)usbif->conn_ring_area->addr,
> >> GNTMAP_host_map, conn_ring_ref, usbif->domid);
> >>
> >> - if (HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &op, 1))
> >> - BUG();
> >> + gnttab_check_GNTST_eagain_do_while(GNTTABOP_map_grant_ref, &op);
> >>
> >> - if (op.status) {
> >> + if (op.status != GNTST_okay) {
> >> struct gnttab_unmap_grant_ref unop;
> >> gnttab_set_unmap_op(&unop,
> >> (unsigned long) usbif->urb_ring_area->addr,
> >> GNTMAP_host_map, usbif->urb_shmem_handle);
> >> VOID(HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, &unop,
> >> 1));
> >> - printk(KERN_ERR "grant table failure mapping conn_ring_ref\n");
> >> + printk(KERN_ERR "grant table failure mapping conn_ring_ref
> >> %d\n",
> >> + (int) op.status);
> >> return op.status;
> >> }
> >>
> >> diff -r df9e25a0189b -r 1170bc32db41 drivers/xen/usbback/usbback.c
> >> --- a/drivers/xen/usbback/usbback.c
> >> +++ b/drivers/xen/usbback/usbback.c
> >> @@ -428,7 +428,9 @@ static int usbbk_gnttab_map(usbif_t *usb
> >> BUG_ON(ret);
> >>
> >> for (i = 0; i < nr_segs; i++) {
> >> - if (unlikely(map[i].status != 0)) {
> >> + if (unlikely(map[i].status == GNTST_eagain))
> >> +
> >> gnttab_check_GNTST_eagain_while(GNTTABOP_map_grant_ref, &map[i]);
> >> + if (unlikely(map[i].status != GNTST_okay)) {
> >> printk(KERN_ERR "usbback: invalid buffer --
> >> could not remap it\n");
> >> map[i].handle = USBBACK_INVALID_HANDLE;
> >> ret |= 1;
> >> diff -r df9e25a0189b -r 1170bc32db41
> >> drivers/xen/xenbus/xenbus_backend_client.c
> >> --- a/drivers/xen/xenbus/xenbus_backend_client.c
> >> +++ b/drivers/xen/xenbus/xenbus_backend_client.c
> >> @@ -48,8 +48,7 @@ struct vm_struct *xenbus_map_ring_valloc
> >> gnttab_set_map_op(&op, (unsigned long)area->addr, GNTMAP_host_map,
> >> gnt_ref, dev->otherend_id);
> >>
> >> - if (HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &op, 1))
> >> - BUG();
> >> + gnttab_check_GNTST_eagain_do_while(GNTTABOP_map_grant_ref, &op);
> >>
> >> if (op.status != GNTST_okay) {
> >> free_vm_area(area);
> >> @@ -75,15 +74,16 @@ int xenbus_map_ring(struct xenbus_device
> >>
> >> gnttab_set_map_op(&op, (unsigned long)vaddr, GNTMAP_host_map,
> >> gnt_ref, dev->otherend_id);
> >> - if (HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &op, 1))
> >> - BUG();
> >> + gnttab_check_GNTST_eagain_do_while(GNTTABOP_map_grant_ref, &op);
> >>
> >> 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
> >> + } else {
> >> *handle = op.handle;
> >> + return 0;
> >> + }
> >>
> >> return op.status;
> >> }
> >> diff -r df9e25a0189b -r 1170bc32db41 include/xen/gnttab.h
> >> --- a/include/xen/gnttab.h
> >> +++ b/include/xen/gnttab.h
> >> @@ -187,4 +187,41 @@ gnttab_set_replace_op(struct gnttab_unma
> >> unmap->handle = handle;
> >> }
> >>
> >> +#define gnttab_check_GNTST_eagain_while(__HCop, __HCarg_p)
> >> \
> >> +do {
> >> \
> >> + u8 __hc_delay = 1;
> >> \
> >> + int __ret;
> >> \
> >> + while (unlikely((__HCarg_p)->status == GNTST_eagain && __hc_delay))
> >> { \
> >> + msleep(__hc_delay++);
> >> \
> >> + __ret = HYPERVISOR_grant_table_op(__HCop, (__HCarg_p), 1);
> >> \
> >> + BUG_ON(__ret);
> >> \
> >> + }
> >> \
> >> + if (__hc_delay == 0) {
> >> \
> >> + printk(KERN_ERR "%s: %s gnt busy\n", __func__, current->comm);
> >> \
> >> + (__HCarg_p)->status = GNTST_bad_page;
> >> \
> >> + }
> >> \
> >> + if ((__HCarg_p)->status != GNTST_okay)
> >> \
> >> + printk(KERN_ERR "%s: %s gnt status %x\n",
> >> \
> >> + __func__, current->comm, (__HCarg_p)->status);
> >> \
> >> +} while(0)
> >> +
> >> +#define gnttab_check_GNTST_eagain_do_while(__HCop, __HCarg_p)
> >> \
> >> +do {
> >> \
> >> + u8 __hc_delay = 1;
> >> \
> >> + int __ret;
> >> \
> >> + do {
> >> \
> >> + __ret = HYPERVISOR_grant_table_op(__HCop, (__HCarg_p), 1);
> >> \
> >> + BUG_ON(__ret);
> >> \
> >> + if ((__HCarg_p)->status == GNTST_eagain)
> >> \
> >> + msleep(__hc_delay++);
> >> \
> >> + } while ((__HCarg_p)->status == GNTST_eagain && __hc_delay);
> >> \
> >> + if (__hc_delay == 0) {
> >> \
> >> + printk(KERN_ERR "%s: %s gnt busy\n", __func__, current->comm);
> >> \
> >> + (__HCarg_p)->status = GNTST_bad_page;
> >> \
> >> + }
> >> \
> >> + if ((__HCarg_p)->status != GNTST_okay)
> >> \
> >> + printk(KERN_ERR "%s: %s gnt status %x\n",
> >> \
> >> + __func__, current->comm, (__HCarg_p)->status);
> >> \
> >> +} while(0)
> >> +
> >> #endif /* __ASM_GNTTAB_H__ */
> >>
> >> _______________________________________________
> >> Xen-devel mailing list
> >> Xen-devel@xxxxxxxxxxxxxxxxxxx
> >> http://lists.xensource.com/xen-devel
> >
>
>
>
> _______________________________________________
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> Xen-devel@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-devel
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