similar to: xen/blkback: Persistent grant maps for xen blk drivers

Hello Roger Pau Monne, The patch 4d4f270f1880: "xen-blkback: move free persistent grants code" from Nov 16, 2012, leads to the following warning: drivers/block/xen-blkback/blkback.c:238 free_persistent_gnts() warn: 'persistent_gnt' was already freed. drivers/block/xen-blkback/blkback.c 232 pages[segs_to_unmap] = persistent_gnt->page; 233

Hello Roger Pau Monne, The patch 4d4f270f1880: "xen-blkback: move free persistent grants code" from Nov 16, 2012, leads to the following warning: drivers/block/xen-blkback/blkback.c:238 free_persistent_gnts() warn: 'persistent_gnt' was already freed. drivers/block/xen-blkback/blkback.c 232 pages[segs_to_unmap] = persistent_gnt->page; 233

This patch contains fixes for persistent grants implementation v2: * handle == 0 is a valid handle, so initialize grants in blkback setting the handle to BLKBACK_INVALID_HANDLE instead of 0. Reported by Konrad Rzeszutek Wilk. * new_map is a boolean, use "true" or "false" instead of 1 and 0. Reported by Konrad Rzeszutek Wilk. * blkfront announces the

This patch implements persistent grants for the xen-blk{front,back} mechanism. The effect of this change is to reduce the number of unmap operations performed, since they cause a (costly) TLB shootdown. This allows the I/O performance to scale better when a large number of VMs are performing I/O. Previously, the blkfront driver was supplied a bvec[] from the request queue. This was granted to

Moving grant ref handles from blkbk to pending_req will allow us to get rid of the shared blkbk structure. Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: xen-devel@lists.xen.org --- drivers/block/xen-blkback/blkback.c | 16 ++++------------ 1 files changed, 4 insertions(+), 12 deletions(-) diff --git

From: Santosh Jodh <santosh.jodh at citrix.com> Add support for multi page ring for block devices. The number of pages is configurable for blkback via module parameter. blkback reports max-ring-page-order to blkfront via xenstore. blkfront reports its supported ring-page-order to blkback via xenstore. blkfront reports multi page ring references via ring-refNN in xenstore. The change allows

From: Santosh Jodh <santosh.jodh at citrix.com> Add support for multi page ring for block devices. The number of pages is configurable for blkback via module parameter. blkback reports max-ring-page-order to blkfront via xenstore. blkfront reports its supported ring-page-order to blkback via xenstore. blkfront reports multi page ring references via ring-refNN in xenstore. The change allows

From: Santosh Jodh <santosh.jodh at citrix.com> Add support for multi page ring for block devices. The number of pages is configurable for blkback via module parameter. blkback reports max-ring-page-order to blkfront via xenstore. blkfront reports its supported ring-page-order to blkback via xenstore. blkfront reports multi page ring references via ring-refNN in xenstore. The change allows

Hi sahil: I think the reason why you cannot get page shared is due to the gref you got. Gref is responsible for a page allocated from domU, in my understanding it should not be 0, that is a gref 0 can not be shared, that''s why I skip gref 0 to be nominated. The gref is nominated to Xen and later used to find a corrspond MFN, so it shall not always be the same.

In dispatch_rw_block_io after a call to HYPERVISOR_grant_table_op, there is the following code which calls fast_flush_area and breaks out of the loop early if one of the handles returned from HYPERVISOR_grant_table_op is negative: for (i = 0; i < nseg; i++) { if (unlikely(map[i].handle < 0)) { DPRINTK("invalid buffer -- could not remap it\n"); fast_flush_area(pending_idx,

With the introduction of indirect segments we can receive requests with a number of segments bigger than the maximum number of allowed iovecs in a bios, so make sure that blkback doesn't try to allocate a bios with more iovecs than BIO_MAX_PAGES Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> ---

Hey Roger, I tested the feature-persistent patches and they rolled out succesfully out of the test system. This is a bootup test with 32/64 dom0, 32/64 PV/PVHVM domU, with new and old OS-es. I am thinking to send a git pull on Friday to Jens so that they will be part of Linux v3.8.

Rather than just leaking pages that can''t be freed at the point where access permission for the backend domain gets revoked, put them on a list and run a timer to (infrequently) retry freeing them. (This can particularly happen when unloading a frontend driver when devices are still present, and the backend still has them in non-closed state or hasn''t finished closing them yet.)

Dear list, This is the V4 of the trim support for xen-blkfront/blkback, Now we move BLKIF_OP_TRIM to BLKIF_OP_DISCARD, and dropped all "trim" stuffs in the patches, and use "discard" instead. Also we updated the helpers of blkif_x86_{32|64}_request or we will meet problems using a non-native protocol. And this patch has been tested with both SSD and raw file, with SSD we will

- introduce local variables (shortcuts for frequently used <dom>->grant_table) - adjust first parameter of mapcount() - drop lock acquisition from gnttab_get_version() - remove hard tabs and adjust formatting Signed-off-by: Jan Beulich <jbeulich@suse.com> Tested-by: Andrew Thomas <andrew.thomas@oracle.com> --- a/xen/common/grant_table.c +++ b/xen/common/grant_table.c @@

refactoring balback Signed-off-by: Ronghui Duan <ronghui.duan@intel.com<mailto:ronghui.duan@intel.com>> diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c index 73f196c..b4767f5 100644 --- a/drivers/block/xen-blkback/blkback.c +++ b/drivers/block/xen-blkback/blkback.c @@ -64,6 +64,11 @@ MODULE_PARM_DESC(reqs, "Number of blkback requests to

gref->gref_id is unsigned so the error handling didn't work. gnttab_grant_foreign_access() returns an int type, so we can add a cast here, and it doesn't cause any problems. gnttab_grant_foreign_access() can return a variety of errors including -ENOSPC, -ENOSYS and -ENOMEM. Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com> diff --git a/drivers/xen/gntalloc.c

gref->gref_id is unsigned so the error handling didn't work. gnttab_grant_foreign_access() returns an int type, so we can add a cast here, and it doesn't cause any problems. gnttab_grant_foreign_access() can return a variety of errors including -ENOSPC, -ENOSYS and -ENOMEM. Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com> diff --git a/drivers/xen/gntalloc.c

gref->gref_id is unsigned so the error handling didn't work. gnttab_grant_foreign_access() returns an int type, so we can add a cast here, and it doesn't cause any problems. gnttab_grant_foreign_access() can return a variety of errors including -ENOSPC, -ENOSYS and -ENOMEM. Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com> diff --git a/drivers/xen/gntalloc.c

Hi have 4 dom0 with debian lenny running xen. When I run ps axf|grep xvd I see it''s different on diferent dom0s. dom0-A 15677 ? S< 0:00 \_ [blkback.139.xvd] 15678 ? S< 0:38 \_ [blkback.139.xvd] 17015 ? S< 0:00 \_ [blkback.140.xvd] 17016 ? S< 2:34 \_ [blkback.140.xvd] 21309 ? S< 0:00 \_ [blkback.142.xvd] 21310 ?