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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
I had a chance to get a environment up and running with the Kernel
tip, so I've ported these patches. As a requisite, I had to create a
patch that implements MMAP_BATCH_V2 first. I'll be posting the set to
the mailing list very shortly for comment.
I wanted to revive this thread so there was a bit of context.
Cheers,
-Adin
On Fri, Dec 2, 2011 at 11:50 AM, Konrad Rzeszutek Wilk
<konrad@xxxxxxxxxx> wrote:
> 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
>> >
>>
>>
>>
>> _______________________________________________
>> Xen-devel mailing list
>> Xen-devel@xxxxxxxxxxxxxxxxxxx
>> http://lists.xensource.com/xen-devel
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-devel
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