After patch "xen/blkfront: separate per ring information out of device
info", per-ring data is protected by a per-device lock ('io_lock').
This is not a good way and will effect the scalability, so introduce a
per-ring lock ('ring_lock').
The old 'io_lock' is renamed to 'dev_lock' which protects the ->grants list and
->persistent_gnts_c which are shared by all rings.
Note that in 'blkfront_probe' the 'blkfront_info' is setup via kzalloc
so setting ->persistent_gnts_c to zero is not needed.
Signed-off-by: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Preparatory patch for multiple hardware queues (rings). The number of
rings is unconditionally set to 1, larger number will be enabled in
patch "xen/blkfront: negotiate number of queues/rings to be used with backend"
so as to make review easier.
Note that blkfront_gather_backend_features does not call
blkfront_setup_indirect anymore (as that needs to be done per ring).
That means that in blkif_recover/blkif_connect we have to do it in a loop
(bounded by nr_rings).
Signed-off-by: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Split per ring information to a new structure "blkfront_ring_info".
A ring is the representation of a hardware queue, every vbd device can associate
with one or more rings depending on how many hardware queues/rings to be used.
This patch is a preparation for supporting real multi hardware queues/rings.
We also add a backpointer to 'struct blkfront_info' (dev_info) which
is not needed (we could use containers_of) but further patch
("xen/blkfront: pseudo support for multi hardware queues/rings")
will make allocation of 'blkfront_ring_info' dynamic.
Signed-off-by: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
- Improve balloon driver memory hotplug placement.
- Use unpopulated hotplugged memory for foreign pages (if
supported/enabled).
- Support 64 KiB guest pages on arm64.
- CPU hotplug support on arm/arm64.
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Merge tag 'for-linus-4.4-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen updates from David Vrabel:
- Improve balloon driver memory hotplug placement.
- Use unpopulated hotplugged memory for foreign pages (if
supported/enabled).
- Support 64 KiB guest pages on arm64.
- CPU hotplug support on arm/arm64.
* tag 'for-linus-4.4-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (44 commits)
xen: fix the check of e_pfn in xen_find_pfn_range
x86/xen: add reschedule point when mapping foreign GFNs
xen/arm: don't try to re-register vcpu_info on cpu_hotplug.
xen, cpu_hotplug: call device_offline instead of cpu_down
xen/arm: Enable cpu_hotplug.c
xenbus: Support multiple grants ring with 64KB
xen/grant-table: Add an helper to iterate over a specific number of grants
xen/xenbus: Rename *RING_PAGE* to *RING_GRANT*
xen/arm: correct comment in enlighten.c
xen/gntdev: use types from linux/types.h in userspace headers
xen/gntalloc: use types from linux/types.h in userspace headers
xen/balloon: Use the correct sizeof when declaring frame_list
xen/swiotlb: Add support for 64KB page granularity
xen/swiotlb: Pass addresses rather than frame numbers to xen_arch_need_swiotlb
arm/xen: Add support for 64KB page granularity
xen/privcmd: Add support for Linux 64KB page granularity
net/xen-netback: Make it running on 64KB page granularity
net/xen-netfront: Make it running on 64KB page granularity
block/xen-blkback: Make it running on 64KB page granularity
block/xen-blkfront: Make it running on 64KB page granularity
...
Linux may use a different page size than the size of grant. So make
clear that the order is actually in number of grant.
Signed-off-by: Julien Grall <julien.grall@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
The PV block protocol is using 4KB page granularity. The goal of this
patch is to allow a Linux using 64KB page granularity using block
device on a non-modified Xen.
The block API is using segment which should at least be the size of a
Linux page. Therefore, the driver will have to break the page in chunk
of 4K before giving the page to the backend.
When breaking a 64KB segment in 4KB chunks, it is possible that some
chunks are empty. As the PV protocol always require to have data in the
chunk, we have to count the number of Xen page which will be in use and
avoid sending empty chunks.
Note that, a pre-defined number of grants are reserved before preparing
the request. This pre-defined number is based on the number and the
maximum size of the segments. If each segment contains a very small
amount of data, the driver may reserve too many grants (16 grants is
reserved per segment with 64KB page granularity).
Furthermore, in the case of persistent grants we allocate one Linux page
per grant although only the first 4KB of the page will be effectively
in use. This could be improved by sharing the page with multiple grants.
Signed-off-by: Julien Grall <julien.grall@citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Prepare the code to support 64KB page granularity. The first
implementation will use a full Linux page per indirect and persistent
grant. When non-persistent grant is used, each page of a bio request
may be split in multiple grant.
Furthermore, the field page of the grant structure is only used to copy
data from persistent grant or indirect grant. Avoid to set it for other
use case as it will have no meaning given the page will be split in
multiple grant.
Provide 2 functions, to setup indirect grant, the other for bio page.
Signed-off-by: Julien Grall <julien.grall@citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
All the usage of the field pfn are done using the same idiom:
pfn_to_page(grant->pfn)
This will return always the same page. Store directly the page in the
grant to clean up the code.
Signed-off-by: Julien Grall <julien.grall@citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Currently, blkif_queue_request has 2 distinct execution path:
- Send a discard request
- Send a read/write request
The function is also allocating grants to use for generating the
request. Although, this is only used for read/write request.
Rather than having a function with 2 distinct execution path, separate
the function in 2. This will also remove one level of tabulation.
Signed-off-by: Julien Grall <julien.grall@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Konrad writes:
Please git pull an update branch to your 'for-4.3/drivers' branch (which
oddly I don't see does not have the previous pull?)
git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git stable/for-jens-4.3
which has two fixes - one where we use the Xen blockfront EFI driver and
don't release all the requests, the other if the allocation of resources
for a particular state failed - we would go back 'Closing' and assume
that an structure would be allocated while in fact it may not be - and
crash.
xen-blkfront will crash if the check to talk_to_blkback()
in blkback_changed()(XenbusStateInitWait) returns an error.
The driver data is freed and info is set to NULL. Later during
the close process via talk_to_blkback's call to xenbus_dev_fatal()
the null pointer is passed to and dereference in blkfront_closing.
CC: stable@vger.kernel.org
Signed-off-by: Cathy Avery <cathy.avery@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
blk_mq_complete_request may be a no-op if the request has already
been completed by others means (e.g. a timeout or cancellation), but
currently drivers have to set rq->errors before calling
blk_mq_complete_request, which might leave us with the wrong error value.
Add an error parameter to blk_mq_complete_request so that we can
defer setting rq->errors until we known we won the race to complete the
request.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
- Use the correct GFN/BFN terms more consistently.
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Merge tag 'for-linus-4.3-rc0b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen terminology fixes from David Vrabel:
"Use the correct GFN/BFN terms more consistently"
* tag 'for-linus-4.3-rc0b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen/xenbus: Rename the variable xen_store_mfn to xen_store_gfn
xen/privcmd: Further s/MFN/GFN/ clean-up
hvc/xen: Further s/MFN/GFN clean-up
video/xen-fbfront: Further s/MFN/GFN clean-up
xen/tmem: Use xen_page_to_gfn rather than pfn_to_gfn
xen: Use correctly the Xen memory terminologies
arm/xen: implement correctly pfn_to_mfn
xen: Make clear that swiotlb and biomerge are dealing with DMA address
- Convert xen-blkfront to the multiqueue API
- [arm] Support binding event channels to different VCPUs.
- [x86] Support > 512 GiB in a PV guests (off by default as such a
guest cannot be migrated with the current toolstack).
- [x86] PMU support for PV dom0 (limited support for using perf with
Xen and other guests).
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Merge tag 'for-linus-4.3-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen updates from David Vrabel:
"Xen features and fixes for 4.3:
- Convert xen-blkfront to the multiqueue API
- [arm] Support binding event channels to different VCPUs.
- [x86] Support > 512 GiB in a PV guests (off by default as such a
guest cannot be migrated with the current toolstack).
- [x86] PMU support for PV dom0 (limited support for using perf with
Xen and other guests)"
* tag 'for-linus-4.3-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (33 commits)
xen: switch extra memory accounting to use pfns
xen: limit memory to architectural maximum
xen: avoid another early crash of memory limited dom0
xen: avoid early crash of memory limited dom0
arm/xen: Remove helpers which are PV specific
xen/x86: Don't try to set PCE bit in CR4
xen/PMU: PMU emulation code
xen/PMU: Intercept PMU-related MSR and APIC accesses
xen/PMU: Describe vendor-specific PMU registers
xen/PMU: Initialization code for Xen PMU
xen/PMU: Sysfs interface for setting Xen PMU mode
xen: xensyms support
xen: remove no longer needed p2m.h
xen: allow more than 512 GB of RAM for 64 bit pv-domains
xen: move p2m list if conflicting with e820 map
xen: add explicit memblock_reserve() calls for special pages
mm: provide early_memremap_ro to establish read-only mapping
xen: check for initrd conflicting with e820 map
xen: check pre-allocated page tables for conflict with memory map
xen: check for kernel memory conflicting with memory layout
...
Based on include/xen/mm.h [1], Linux is mistakenly using MFN when GFN
is meant, I suspect this is because the first support for Xen was for
PV. This resulted in some misimplementation of helpers on ARM and
confused developers about the expected behavior.
For instance, with pfn_to_mfn, we expect to get an MFN based on the name.
Although, if we look at the implementation on x86, it's returning a GFN.
For clarity and avoid new confusion, replace any reference to mfn with
gfn in any helpers used by PV drivers. The x86 code will still keep some
reference of pfn_to_mfn which may be used by all kind of guests
No changes as been made in the hypercall field, even
though they may be invalid, in order to keep the same as the defintion
in xen repo.
Note that page_to_mfn has been renamed to xen_page_to_gfn to avoid a
name to close to the KVM function gfn_to_page.
Take also the opportunity to simplify simple construction such
as pfn_to_mfn(page_to_pfn(page)) into xen_page_to_gfn. More complex clean up
will come in follow-up patches.
[1] http://xenbits.xen.org/gitweb/?p=xen.git;a=commitdiff;h=e758ed14f390342513405dd766e874934573e6cb
Signed-off-by: Julien Grall <julien.grall@citrix.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Pull core block updates from Jens Axboe:
"This first core part of the block IO changes contains:
- Cleanup of the bio IO error signaling from Christoph. We used to
rely on the uptodate bit and passing around of an error, now we
store the error in the bio itself.
- Improvement of the above from myself, by shrinking the bio size
down again to fit in two cachelines on x86-64.
- Revert of the max_hw_sectors cap removal from a revision again,
from Jeff Moyer. This caused performance regressions in various
tests. Reinstate the limit, bump it to a more reasonable size
instead.
- Make /sys/block/<dev>/queue/discard_max_bytes writeable, by me.
Most devices have huge trim limits, which can cause nasty latencies
when deleting files. Enable the admin to configure the size down.
We will look into having a more sane default instead of UINT_MAX
sectors.
- Improvement of the SGP gaps logic from Keith Busch.
- Enable the block core to handle arbitrarily sized bios, which
enables a nice simplification of bio_add_page() (which is an IO hot
path). From Kent.
- Improvements to the partition io stats accounting, making it
faster. From Ming Lei.
- Also from Ming Lei, a basic fixup for overflow of the sysfs pending
file in blk-mq, as well as a fix for a blk-mq timeout race
condition.
- Ming Lin has been carrying Kents above mentioned patches forward
for a while, and testing them. Ming also did a few fixes around
that.
- Sasha Levin found and fixed a use-after-free problem introduced by
the bio->bi_error changes from Christoph.
- Small blk cgroup cleanup from Viresh Kumar"
* 'for-4.3/core' of git://git.kernel.dk/linux-block: (26 commits)
blk: Fix bio_io_vec index when checking bvec gaps
block: Replace SG_GAPS with new queue limits mask
block: bump BLK_DEF_MAX_SECTORS to 2560
Revert "block: remove artifical max_hw_sectors cap"
blk-mq: fix race between timeout and freeing request
blk-mq: fix buffer overflow when reading sysfs file of 'pending'
Documentation: update notes in biovecs about arbitrarily sized bios
block: remove bio_get_nr_vecs()
fs: use helper bio_add_page() instead of open coding on bi_io_vec
block: kill merge_bvec_fn() completely
md/raid5: get rid of bio_fits_rdev()
md/raid5: split bio for chunk_aligned_read
block: remove split code in blkdev_issue_{discard,write_same}
btrfs: remove bio splitting and merge_bvec_fn() calls
bcache: remove driver private bio splitting code
block: simplify bio_add_page()
block: make generic_make_request handle arbitrarily sized bios
blk-cgroup: Drop unlikely before IS_ERR(_OR_NULL)
block: don't access bio->bi_error after bio_put()
block: shrink struct bio down to 2 cache lines again
...
Note: This patch is based on original work of Arianna's internship for
GNOME's Outreach Program for Women.
Only one hardware queue is used now, so there is no significant
performance change
The legacy non-mq code is deleted completely which is the same as other
drivers like virtio, mtip, and nvme.
Also dropped one unnecessary holding of info->io_lock when calling
blk_mq_stop_hw_queues().
Signed-off-by: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Bob Liu <bob.liu@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jens Axboe <axboe@fb.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Currently we have two different ways to signal an I/O error on a BIO:
(1) by clearing the BIO_UPTODATE flag
(2) by returning a Linux errno value to the bi_end_io callback
The first one has the drawback of only communicating a single possible
error (-EIO), and the second one has the drawback of not beeing persistent
when bios are queued up, and are not passed along from child to parent
bio in the ever more popular chaining scenario. Having both mechanisms
available has the additional drawback of utterly confusing driver authors
and introducing bugs where various I/O submitters only deal with one of
them, and the others have to add boilerplate code to deal with both kinds
of error returns.
So add a new bi_error field to store an errno value directly in struct
bio and remove the existing mechanisms to clean all this up.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Konrad writes:
"There are three bugs that have been found in the xen-blkfront (and
backend). Two of them have the stable tree CC-ed. They have been found
where an guest is migrating to a host that is missing
'feature-persistent' support (from one that has it enabled). We end up
hitting an BUG() in the driver code."
We should consider info->feature_persistent when adding indirect page to list
info->indirect_pages, else the BUG_ON() in blkif_free() would be triggered.
When we are using persistent grants the indirect_pages list
should always be empty because blkfront has pre-allocated enough
persistent pages to fill all requests on the ring.
CC: stable@vger.kernel.org
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
There is a bug when migrate from !feature-persistent host to feature-persistent
host, because domU still thinks new host/backend doesn't support persistent.
Dmesg like:
backed has not unmapped grant: 839
backed has not unmapped grant: 773
backed has not unmapped grant: 773
backed has not unmapped grant: 773
backed has not unmapped grant: 839
The fix is to recheck feature-persistent of new backend in blkif_recover().
See: https://lkml.org/lkml/2015/5/25/469
As Roger suggested, we can split the part of blkfront_connect that checks for
optional features, like persistent grants, indirect descriptors and
flush/barrier features to a separate function and call it from both
blkfront_connect and blkif_recover
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
- Add "make xenconfig" to assist in generating configs for Xen guests.
- Preparatory cleanups necessary for supporting 64 KiB pages in ARM
guests.
- Automatically use hvc0 as the default console in ARM guests.
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Merge tag 'for-linus-4.2-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen updates from David Vrabel:
"Xen features and cleanups for 4.2-rc0:
- add "make xenconfig" to assist in generating configs for Xen guests
- preparatory cleanups necessary for supporting 64 KiB pages in ARM
guests
- automatically use hvc0 as the default console in ARM guests"
* tag 'for-linus-4.2-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
block/xen-blkback: s/nr_pages/nr_segs/
block/xen-blkfront: Remove invalid comment
block/xen-blkfront: Remove unused macro MAXIMUM_OUTSTANDING_BLOCK_REQS
arm/xen: Drop duplicate define mfn_to_virt
xen/grant-table: Remove unused macro SPP
xen/xenbus: client: Fix call of virt_to_mfn in xenbus_grant_ring
xen: Include xen/page.h rather than asm/xen/page.h
kconfig: add xenconfig defconfig helper
kconfig: clarify kvmconfig is for kvm
xen/pcifront: Remove usage of struct timeval
xen/tmem: use BUILD_BUG_ON() in favor of BUG_ON()
hvc_xen: avoid uninitialized variable warning
xenbus: avoid uninitialized variable warning
xen/arm: allow console=hvc0 to be omitted for guests
arm,arm64/xen: move Xen initialization earlier
arm/xen: Correctly check if the event channel interrupt is present
Patch 69b91ede5c
"drivers: xen-blkback: delay pending_req allocation to connect_ring"
exposed an problem that Xen blkfront has. There is a race
with XenStored and the drivers such that we can see two:
vbd vbd-268440320: blkfront:blkback_changed to state 2.
vbd vbd-268440320: blkfront:blkback_changed to state 2.
vbd vbd-268440320: blkfront:blkback_changed to state 4.
state changes to XenbusStateInitWait ('2'). The end result is that
blkback_changed() receives two notify and calls twice setup_blkring().
While the backend driver may only get the first setup_blkring() which is
wrong and reads out-dated (or reads them as they are being updated
with new ring-ref values).
The end result is that the ring ends up being incorrectly set.
The other drivers in the tree have such checks already in.
Reported-and-Tested-by: Robert Butera <robert.butera@oracle.com>
Signed-off-by: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Since commit b764915 "xen-blkfront: use a different scatterlist for each
request", biovec has been replaced by scatterlist when copying back the
data during a completion request.
Signed-off-by: Julien Grall <julien.grall@citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Extend xen/block to support multi-page ring, so that more requests can be
issued by using more than one pages as the request ring between blkfront
and backend.
As a result, the performance can get improved significantly.
We got some impressive improvements on our highend iscsi storage cluster
backend. If using 64 pages as the ring, the IOPS increased about 15 times
for the throughput testing and above doubled for the latency testing.
The reason was the limit on outstanding requests is 32 if use only one-page
ring, but in our case the iscsi lun was spread across about 100 physical
drives, 32 was really not enough to keep them busy.
Changes in v2:
- Rebased to 4.0-rc6.
- Document on how multi-page ring feature working to linux io/blkif.h.
Changes in v3:
- Remove changes to linux io/blkif.h and follow the protocol defined
in io/blkif.h of XEN tree.
- Rebased to 4.1-rc3
Changes in v4:
- Turn to use 'ring-page-order' and 'max-ring-page-order'.
- A few comments from Roger.
Changes in v5:
- Clarify with 4k granularity to comment
- Address more comments from Roger
Signed-off-by: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
The major responsibility of talk_to_blkback() is allocate and initialize
the request ring and write the ring info to xenstore.
But this work should be done after backend entered 'XenbusStateInitWait' as
defined in the protocol file.
See xen/include/public/io/blkif.h in XEN git tree:
Front Back
================================= =====================================
XenbusStateInitialising XenbusStateInitialising
o Query virtual device o Query backend device identification
properties. data.
o Setup OS device instance. o Open and validate backend device.
o Publish backend features and
transport parameters.
|
|
V
XenbusStateInitWait
o Query backend features and
transport parameters.
o Allocate and initialize the
request ring.
There is no problem with this yet, but it is an violation of the design and
furthermore it would not allow frontend/backend to negotiate 'multi-page'
and 'multi-queue' features.
Changes in v2:
- Re-write the commit message to be more clear.
Signed-off-by: Bob Liu <bob.liu@oracle.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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>
Merge third set of updates from Andrew Morton:
- the rest of MM
[ This includes getting rid of the numa hinting bits, in favor of
just generic protnone logic. Yay. - Linus ]
- core kernel
- procfs
- some of lib/ (lots of lib/ material this time)
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (104 commits)
lib/lcm.c: replace include
lib/percpu_ida.c: remove redundant includes
lib/strncpy_from_user.c: replace module.h include
lib/stmp_device.c: replace module.h include
lib/sort.c: move include inside #if 0
lib/show_mem.c: remove redundant include
lib/radix-tree.c: change to simpler include
lib/plist.c: remove redundant include
lib/nlattr.c: remove redundant include
lib/kobject_uevent.c: remove redundant include
lib/llist.c: remove redundant include
lib/md5.c: simplify include
lib/list_sort.c: rearrange includes
lib/genalloc.c: remove redundant include
lib/idr.c: remove redundant include
lib/halfmd4.c: simplify includes
lib/dynamic_queue_limits.c: simplify includes
lib/sort.c: use simpler includes
lib/interval_tree.c: simplify includes
hexdump: make it return number of bytes placed in buffer
...
__FUNCTION__ hasn't been treated as a string literal since gcc 3.4, so
this only helps people who only test-compile using 3.3 (compiler-gcc3.h
barks at anything older than that). Besides, there are almost no
occurrences of __FUNCTION__ left in the tree.
[akpm@linux-foundation.org: convert remaining __FUNCTION__ references]
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Current migration code uses blk_put_request in order to finish a request
before requeuing it. This function doesn't update the statistics of the
queue, which completely screws accounting. Use blk_end_request_all instead
which properly updates the statistics of the queue.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reported-and-Tested-by: Ouyang Zhaowei (Charles) <ouyangzhaowei@huawei.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: xen-devel@lists.xenproject.org
flush_op is unambiguously defined by feature_flush:
REQ_FUA | REQ_FLUSH -> BLKIF_OP_WRITE_BARRIER
REQ_FLUSH -> BLKIF_OP_FLUSH_DISKCACHE
0 -> 0
and thus can be removed. This is just a cleanup.
The patch was suggested by Boris Ostrovsky.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Guard against issuing unsupported REQ_FUA and REQ_FLUSH was introduced
in d11e61583 and was factored out into blkif_request_flush_valid() in
0f1ca65ee. However:
1) This check in incomplete. In case we negotiated to feature_flush = REQ_FLUSH
and flush_op = BLKIF_OP_FLUSH_DISKCACHE (so FUA is unsupported) FUA request
will still pass the check.
2) blkif_request_flush_valid() is misnamed. It is bool but returns true when
the request is invalid.
3) When blkif_request_flush_valid() fails -EIO is being returned. It seems that
-EOPNOTSUPP is more appropriate here.
Fix all of the above issues.
This patch is based on the original patch by Laszlo Ersek and a comment by
Jeff Moyer.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Pull block layer driver update from Jens Axboe:
"This is the block driver pull request for 3.18. Not a lot in there
this round, and nothing earth shattering.
- A round of drbd fixes from the linbit team, and an improvement in
asender performance.
- Removal of deprecated (and unused) IRQF_DISABLED flag in rsxx and
hd from Michael Opdenacker.
- Disable entropy collection from flash devices by default, from Mike
Snitzer.
- A small collection of xen blkfront/back fixes from Roger Pau Monné
and Vitaly Kuznetsov"
* 'for-3.18/drivers' of git://git.kernel.dk/linux-block:
block: disable entropy contributions for nonrot devices
xen, blkfront: factor out flush-related checks from do_blkif_request()
xen-blkback: fix leak on grant map error path
xen/blkback: unmap all persistent grants when frontend gets disconnected
rsxx: Remove deprecated IRQF_DISABLED
block: hd: remove deprecated IRQF_DISABLED
drbd: use RB_DECLARE_CALLBACKS() to define augment callbacks
drbd: compute the end before rb_insert_augmented()
drbd: Add missing newline in resync progress display in /proc/drbd
drbd: reduce lock contention in drbd_worker
drbd: Improve asender performance
drbd: Get rid of the WORK_PENDING macro
drbd: Get rid of the __no_warn and __cond_lock macros
drbd: Avoid inconsistent locking warning
drbd: Remove superfluous newline from "resync_extents" debugfs entry.
drbd: Use consistent names for all the bi_end_io callbacks
drbd: Use better variable names
The DEFINE_XENBUS_DRIVER() macro looks a bit weird and causes sparse
errors.
Replace the uses with standard structure definitions instead. This is
similar to pci and usb device registration.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
This commit factors out some checks related to the request insertion
path, which can be done in an function instead of by itself.
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Konrad writes:
Please git pull the following branch:
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip.git stable/for-jens-3.16
which has a bunch of fixes to the Xen block frontend and backend driver
and a new parameter for Xen backend driver - an override (set by the toolstack)
whether to expose the discard support (if disk of course supports it) or not.
In its initial implementation a check for "type" was added, but only phy
and file are handled. This breaks advertised discard support for other
type values such as qdisk.
Fix and simplify this function: If the backend advertises discard
support it is supposed to implement it properly, so enable
feature_discard unconditionally. If the backend advertises the need for
a certain granularity and alignment then propagate both properties to
the blocklayer. The discard-secure property is a boolean, update the code
to reflect that.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This was used in the olden days, back when onions were proper
yellow. Basically it mapped to the current buffer to be
transferred. With highmem being added more than a decade ago,
most drivers map pages out of a bio, and rq->buffer isn't
pointing at anything valid.
Convert old style drivers to just use bio_data().
For the discard payload use case, just reference the page
in the bio.
Signed-off-by: Jens Axboe <axboe@fb.com>
Konrad writes:
Please git pull the following branch:
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip.git stable/for-jens-3.14
which is based off v3.13-rc6. If you would like me to rebase it on
a different branch/tag I would be more than happy to do so.
The patches are all bug-fixes and hopefully can go in 3.14.
They deal with xen-blkback shutdown and cause memory leaks
as well as shutdown races. They should go to stable tree and if you
are OK with I will ask them to backport those fixes.
There is also a fix to xen-blkfront to deal with unexpected state
transition. And lastly a fix to the header where it was using the
__aligned__ unnecessarily.
Backend drivers shouldn't transistion to CLOSED unless the frontend is
CLOSED. If a backend does transition to CLOSED too soon then the
frontend may not see the CLOSING state and will not properly shutdown.
So, treat an unexpected backend CLOSED state the same as CLOSING.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This was wrongly introduced in commit 402b27f9, the only difference
between blkif_request_segment_aligned and blkif_request_segment is
that the former has a named padding, while both share the same
memory layout.
Also correct a few minor glitches in the description, including for it
to no longer assume PAGE_SIZE == 4096.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
[Description fix by Jan Beulich]
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reported-by: Jan Beulich <jbeulich@suse.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Tested-by: Matt Rushton <mrushton@amazon.com>
Cc: Matt Wilson <msw@amazon.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Pull core block IO changes from Jens Axboe:
"The major piece in here is the immutable bio_ve series from Kent, the
rest is fairly minor. It was supposed to go in last round, but
various issues pushed it to this release instead. The pull request
contains:
- Various smaller blk-mq fixes from different folks. Nothing major
here, just minor fixes and cleanups.
- Fix for a memory leak in the error path in the block ioctl code
from Christian Engelmayer.
- Header export fix from CaiZhiyong.
- Finally the immutable biovec changes from Kent Overstreet. This
enables some nice future work on making arbitrarily sized bios
possible, and splitting more efficient. Related fixes to immutable
bio_vecs:
- dm-cache immutable fixup from Mike Snitzer.
- btrfs immutable fixup from Muthu Kumar.
- bio-integrity fix from Nic Bellinger, which is also going to stable"
* 'for-3.14/core' of git://git.kernel.dk/linux-block: (44 commits)
xtensa: fixup simdisk driver to work with immutable bio_vecs
block/blk-mq-cpu.c: use hotcpu_notifier()
blk-mq: for_each_* macro correctness
block: Fix memory leak in rw_copy_check_uvector() handling
bio-integrity: Fix bio_integrity_verify segment start bug
block: remove unrelated header files and export symbol
blk-mq: uses page->list incorrectly
blk-mq: use __smp_call_function_single directly
btrfs: fix missing increment of bi_remaining
Revert "block: Warn and free bio if bi_end_io is not set"
block: Warn and free bio if bi_end_io is not set
blk-mq: fix initializing request's start time
block: blk-mq: don't export blk_mq_free_queue()
block: blk-mq: make blk_sync_queue support mq
block: blk-mq: support draining mq queue
dm cache: increment bi_remaining when bi_end_io is restored
block: fixup for generic bio chaining
block: Really silence spurious compiler warnings
block: Silence spurious compiler warnings
block: Kill bio_pair_split()
...
The user has the option of disabling the platform driver:
00:02.0 Unassigned class [ff80]: XenSource, Inc. Xen Platform Device (rev 01)
which is used to unplug the emulated drivers (IDE, Realtek 8169, etc)
and allow the PV drivers to take over. If the user wishes
to disable that they can set:
xen_platform_pci=0
(in the guest config file)
or
xen_emul_unplug=never
(on the Linux command line)
except it does not work properly. The PV drivers still try to
load and since the Xen platform driver is not run - and it
has not initialized the grant tables, most of the PV drivers
stumble upon:
input: Xen Virtual Keyboard as /devices/virtual/input/input5
input: Xen Virtual Pointer as /devices/virtual/input/input6M
------------[ cut here ]------------
kernel BUG at /home/konrad/ssd/konrad/linux/drivers/xen/grant-table.c:1206!
invalid opcode: 0000 [#1] SMP
Modules linked in: xen_kbdfront(+) xenfs xen_privcmd
CPU: 6 PID: 1389 Comm: modprobe Not tainted 3.13.0-rc1upstream-00021-ga6c892b-dirty #1
Hardware name: Xen HVM domU, BIOS 4.4-unstable 11/26/2013
RIP: 0010:[<ffffffff813ddc40>] [<ffffffff813ddc40>] get_free_entries+0x2e0/0x300
Call Trace:
[<ffffffff8150d9a3>] ? evdev_connect+0x1e3/0x240
[<ffffffff813ddd0e>] gnttab_grant_foreign_access+0x2e/0x70
[<ffffffffa0010081>] xenkbd_connect_backend+0x41/0x290 [xen_kbdfront]
[<ffffffffa0010a12>] xenkbd_probe+0x2f2/0x324 [xen_kbdfront]
[<ffffffff813e5757>] xenbus_dev_probe+0x77/0x130
[<ffffffff813e7217>] xenbus_frontend_dev_probe+0x47/0x50
[<ffffffff8145e9a9>] driver_probe_device+0x89/0x230
[<ffffffff8145ebeb>] __driver_attach+0x9b/0xa0
[<ffffffff8145eb50>] ? driver_probe_device+0x230/0x230
[<ffffffff8145eb50>] ? driver_probe_device+0x230/0x230
[<ffffffff8145cf1c>] bus_for_each_dev+0x8c/0xb0
[<ffffffff8145e7d9>] driver_attach+0x19/0x20
[<ffffffff8145e260>] bus_add_driver+0x1a0/0x220
[<ffffffff8145f1ff>] driver_register+0x5f/0xf0
[<ffffffff813e55c5>] xenbus_register_driver_common+0x15/0x20
[<ffffffff813e76b3>] xenbus_register_frontend+0x23/0x40
[<ffffffffa0015000>] ? 0xffffffffa0014fff
[<ffffffffa001502b>] xenkbd_init+0x2b/0x1000 [xen_kbdfront]
[<ffffffff81002049>] do_one_initcall+0x49/0x170
.. snip..
which is hardly nice. This patch fixes this by having each
PV driver check for:
- if running in PV, then it is fine to execute (as that is their
native environment).
- if running in HVM, check if user wanted 'xen_emul_unplug=never',
in which case bail out and don't load any PV drivers.
- if running in HVM, and if PCI device 5853:0001 (xen_platform_pci)
does not exist, then bail out and not load PV drivers.
- (v2) if running in HVM, and if the user wanted 'xen_emul_unplug=ide-disks',
then bail out for all PV devices _except_ the block one.
Ditto for the network one ('nics').
- (v2) if running in HVM, and if the user wanted 'xen_emul_unplug=unnecessary'
then load block PV driver, and also setup the legacy IDE paths.
In (v3) make it actually load PV drivers.
Reported-by: Sander Eikelenboom <linux@eikelenboom.it
Reported-by: Anthony PERARD <anthony.perard@citrix.com>
Reported-and-Tested-by: Fabio Fantoni <fabio.fantoni@m2r.biz>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[v2: Add extra logic to handle the myrid ways 'xen_emul_unplug'
can be used per Ian and Stefano suggestion]
[v3: Make the unnecessary case work properly]
[v4: s/disks/ide-disks/ spotted by Fabio]
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com> [for PCI parts]
CC: stable@vger.kernel.org
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Merge tag 'v3.13-rc6' into for-3.14/core
Needed to bring blk-mq uptodate, since changes have been going in
since for-3.14/core was established.
Fixup merge issues related to the immutable biovec changes.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Conflicts:
block/blk-flush.c
fs/btrfs/check-integrity.c
fs/btrfs/extent_io.c
fs/btrfs/scrub.c
fs/logfs/dev_bdev.c
In the blkif_release function the bdget_disk() call might returns
a NULL ptr which might be dereferenced on bdev->bd_openers checking
Signed-off-by: Felipe Pena <felipensp@gmail.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[v2: Added WARN per Roger's suggestion]
pfn cannot actually be used unless (!info->feature_persistent), nor is
pfn accessed in get_grant() unless (!info->feature_persistent), but silence
this warning anyway. gcc-4.8
drivers/block/xen-blkfront.c: In function 'do_blkif_request':
drivers/block/xen-blkfront.c:508:20: warning: 'pfn' may be used uninitialized in this function [-Wmaybe-uninitialized]
gnt_list_entry = get_grant(&gref_head, pfn, info);
^
drivers/block/xen-blkfront.c:492:19: note: 'pfn' was declared here
unsigned long pfn;
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
When persistent grants were added they were always used, even if the
backend doesn't have this feature (there's no harm in always using the
same set of pages). This restores the old data path when the backend
doesn't have persistent grants, removing the burden of doing a memcpy
when it is not actually needed.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reported-by: Felipe Franciosi <felipe.franciosi@citrix.com>
Cc: Felipe Franciosi <felipe.franciosi@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[v2: Fix up whitespace issues]
Improve the calculation of required grants to process a request by
using nr_phys_segments instead of always assuming a request is going
to use all posible segments.
nr_phys_segments contains the number of scatter-gather DMA addr+len
pairs, which is basically what we put at every granted page.
for_each_sg iterates over the DMA addr+len pairs and uses a grant
page for each of them.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
There's no need to keep the foreign access in a grant if it is not
persistently mapped by the backend. This allows us to free grants that
are not mapped by the backend, thus preventing blkfront from hoarding
all grants.
The main effect of this is that blkfront will only persistently map
the same grants as the backend, and it will always try to use grants
that are already mapped by the backend. Also the number of persistent
grants in blkfront is the same as in blkback (and is controlled by the
value in blkback).
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Matt Wilson <msw@amazon.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Someone cut and pasted md's md_trim_bio() into xen-blkfront.c. Come on,
we should know better than this.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Neil Brown <neilb@suse.de>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Konrad writes:
It has the 'feature-max-indirect-segments' implemented in both backend
and frontend. The current problem with the backend and frontend is that the
segment size is limited to 11 pages. It means we can at most squeeze in 44kB per
request. The ring can hold 32 (next power of two below 36) requests, meaning we
can do 1.4M of outstanding requests. Nowadays that is not enough.
The problem in the past was addressed in two ways - but neither one went upstream.
The first solution to this proposed by Justin from Spectralogic was to negotiate
the segment size. This means that the ‘struct blkif_sring_entry’ is now a variable size.
It can expand from 112 bytes (cover 11 pages of data - 44kB) to 1580 bytes
(256 pages of data - so 1MB). It is a simple extension by just making the array in the
request expand from 11 to a variable size negotiated. But it had limits: this extension
still limits the number of segments per request to 255 (as the total number must be
specified in the request, which only has an 8-bit field for that purpose).
The other solution (from Intel - Ronghui) was to create one extra ring that only has the
‘struct blkif_request_segment’ in them. The ‘struct blkif_request’ would be changed to have
an index in said ‘segment ring’. There is only one segment ring. This means that the size of
the initial ring is still the same. The requests would point to the segment and enumerate out
how many of the indexes it wants to use. The limit is of course the size of the segment.
If one assumes a one-page segment this means we can in one request cover ~4MB.
Those patches were posted as RFC and the author never followed up on the ideas on changing
it to be a bit more flexible.
There is yet another mechanism that could be employed (which these patches implement) - and it
borrows from VirtIO protocol. And that is the ‘indirect descriptors’. This very similar to
what Intel suggests, but with a twist. The twist is to negotiate how many of these
'segment' pages (aka indirect descriptor pages) we want to support (in reality we negotiate
how many entries in the segment we want to cover, and we module the number if it is
bigger than the segment size).
This means that with the existing 36 slots in the ring (single page) we can cover:
32 slots * each blkif_request_indirect covers: 512 * 4096 ~= 64M. Since we ample space
in the blkif_request_indirect to span more than one indirect page, that number (64M)
can be also multiplied by eight = 512MB.
Roger Pau Monne took the idea and implemented them in these patches. They work
great and the corner cases (migration between backends with and without this extension)
work nicely. The backend has a limit right now off how many indirect entries
it can handle: one indirect page, and at maximum 256 entries (out of 512 - so 50% of the page
is used). That comes out to 32 slots * 256 entries in a indirect page * 1 indirect page
per request * 4096 = 32MB.
This is a conservative number that can change in the future. Right now it strikes
a good balance between giving excellent performance, memory usage in the backend, and
balancing the needs of many guests.
In the patchset there is also the split of the blkback structure to be per-VBD.
This means that the spinlock contention we had with many guests trying to do I/O and
all the blkback threads hitting the same lock has been eliminated.
Also there are bug-fixes to deal with oddly sized sectors, insane amounts on
th ring, and also a security fix (posted earlier).
Now that indirect segments are enabled blk_queue_max_hw_sectors must
be set to match the maximum number of sectors we can handle in a
request.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reported-by: Felipe Franciosi <felipe.franciosi@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Currently xen-blkback passes the logical sector size over xenbus and
xen-blkfront sets up the paravirt disk with that logical block size.
But newer drives usually have the logical sector size set to 512 for
compatibility reasons and would show the actual sector size only in
physical sector size.
This results in the device being partitioned and accessed in dom0 with
the correct sector size, but the guest thinks 512 bytes is the correct
block size. And that results in poor performance.
To fix this, blkback gets modified to pass also physical-sector-size
over xenbus and blkfront to use both values to set up the paravirt
disk. I did not just change the passed in sector-size because I am
not sure having a bigger logical sector size than the physical one
is valid (and that would happen if a newer dom0 kernel hits an older
domU kernel). Also this way a domU set up before should still be
accessible (just some tools might detect the unaligned setup).
[v2: Make xenbus write failure non-fatal]
[v3: Use xenbus_scanf instead of xenbus_gather]
[v4: Rebased against segment changes]
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
The max module parameter (by default 32) is the maximum number of
segments that the frontend will negotiate with the backend for indirect
descriptors. Higher value means more potential throughput but more
memory usage. The backend picks the minimum of the frontend and its
default backend value.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
In blkif_queue_request blkfront iterates over the scatterlist in order
to set the segments of the request, and in blkif_completion blkfront
iterates over the raw request, which makes it hard to know the exact
position of the source and destination memory positions.
This can be solved by allocating a scatterlist for each request, that
will be keep until the request is finished, allowing us to copy the
data back to the original memory without having to iterate over the
raw request.
Oracle-Bug: 16660413 - LARGE ASYNCHRONOUS READS APPEAR BROKEN ON 2.6.39-400
CC: stable@vger.kernel.org
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reported-and-Tested-by: Anne Milicia <anne.milicia@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
The value passed is 0 in all but "it can never happen" cases (and those
only in a couple of drivers) *and* it would've been lost on the way
out anyway, even if something tried to pass something meaningful.
Just don't bother.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Indirect descriptors introduce a new block operation
(BLKIF_OP_INDIRECT) that passes grant references instead of segments
in the request. This grant references are filled with arrays of
blkif_request_segment_aligned, this way we can send more segments in a
request.
The proposed implementation sets the maximum number of indirect grefs
(frames filled with blkif_request_segment_aligned) to 256 in the
backend and 32 in the frontend. The value in the frontend has been
chosen experimentally, and the backend value has been set to a sane
value that allows expanding the maximum number of indirect descriptors
in the frontend if needed.
The migration code has changed from the previous implementation, in
which we simply remapped the segments on the shared ring. Now the
maximum number of segments allowed in a request can change depending
on the backend, so we have to requeue all the requests in the ring and
in the queue and split the bios in them if they are bigger than the
new maximum number of segments.
[v2: Fixed minor comments by Konrad.
[v1: Added padding to make the indirect request 64bit aligned.
Added some BUGs, comments; fixed number of indirect pages in
blkif_get_x86_{32/64}_req. Added description about the indirect operation
in blkif.h]
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
[v3: Fixed spaces and tabs mix ups]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
We already have the frame (pfn of the grant page) stored inside struct
grant, so there's no need to keep an aditional list of mapped frames
for a specific request. This reduces memory usage in blkfront.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: xen-devel@lists.xen.org
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This prevents us from having to call alloc_page while we are preparing
the request. Since blkfront was calling alloc_page with a spinlock
held we used GFP_ATOMIC, which can fail if we are requesting a lot of
pages since it is using the emergency memory pools.
Allocating all the pages at init prevents us from having to call
alloc_page, thus preventing possible failures.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: xen-devel@lists.xen.org
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
The git commit f84adf4921
(xen-blkfront: drop the use of llist_for_each_entry_safe)
was a stop-gate to fix a GCC4.1 bug. The appropiate way
is to actually use an list instead of using an llist.
As such this patch replaces the usage of llist with an
list.
Since we always manipulate the list while holding the io_lock, there's
no need for additional locking (llist used previously is safe to use
concurrently without additional locking).
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
CC: stable@vger.kernel.org
[v1: Redid the git commit description]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
The benefits are:
* code is cleaner
* kmemdup adds additional debugging info useful for tracking the real
place where memory was allocated (CONFIG_DEBUG_SLAB).
Signed-off-by: Mihnea Dobrescu-Balaur <mihneadb@gmail.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Replace llist_for_each_entry_safe with a while loop.
llist_for_each_entry_safe can trigger a bug in GCC 4.1, so it's best
to remove it and use a while loop and do the deletion manually.
Specifically this bug can be triggered by hot-unplugging a disk, either
by doing xm block-detach or by save/restore cycle.
BUG: unable to handle kernel paging request at fffffffffffffff0
IP: [<ffffffffa0047223>] blkif_free+0x63/0x130 [xen_blkfront]
The crash call trace is:
...
bad_area_nosemaphore+0x13/0x20
do_page_fault+0x25e/0x4b0
page_fault+0x25/0x30
? blkif_free+0x63/0x130 [xen_blkfront]
blkfront_resume+0x46/0xa0 [xen_blkfront]
xenbus_dev_resume+0x6c/0x140
pm_op+0x192/0x1b0
device_resume+0x82/0x1e0
dpm_resume+0xc9/0x1a0
dpm_resume_end+0x15/0x30
do_suspend+0x117/0x1e0
When drilling down to the assembler code, on newer GCC it does
.L29:
cmpq $-16, %r12 #, persistent_gnt check
je .L30 #, out of the loop
.L25:
... code in the loop
testq %r13, %r13 # n
je .L29 #, back to the top of the loop
cmpq $-16, %r12 #, persistent_gnt check
movq 16(%r12), %r13 # <variable>.node.next, n
jne .L25 #, back to the top of the loop
.L30:
While on GCC 4.1, it is:
L78:
... code in the loop
testq %r13, %r13 # n
je .L78 #, back to the top of the loop
movq 16(%rbx), %r13 # <variable>.node.next, n
jmp .L78 #, back to the top of the loop
Which basically means that the exit loop condition instead of
being:
&(pos)->member != NULL;
is:
;
which makes the loop unbound.
Since xen-blkfront is the only user of the llist_for_each_entry_safe
macro remove it from llist.h.
Orabug: 16263164
CC: stable@vger.kernel.org
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Currently blkfront fails to handle cases in blkif_completion like the
following:
1st loop in rq_for_each_segment
* bv_offset: 3584
* bv_len: 512
* offset += bv_len
* i: 0
2nd loop:
* bv_offset: 0
* bv_len: 512
* i: 0
In the second loop i should be 1, since we assume we only wanted to
read a part of the previous page. This patches fixes this cases where
only a part of the shared page is read, and blkif_completion assumes
that if the bv_offset of a bvec is less than the previous bv_offset
plus the bv_size we have to switch to the next shared page.
Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Cc: linux-kernel@vger.kernel.org
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Implement a safe version of llist_for_each_entry, and use it in
blkif_free. Previously grants where freed while iterating the list,
which lead to dereferences when trying to fetch the next item.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
[v2: Move the llist_for_each_entry_safe in llist.h]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Free the page allocated for the persistent grant.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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 persistent-grants feature as
feature-persistent-grants, use feature-persistent instead which is
consistent with blkback and the public Xen headers.
* Add a consistency check in blkfront to make sure we don't try to
access segments that have not been set.
Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Roger Pau Monne <roger.pau@citrix.com>
[v1: The new_map int->bool had already been changed]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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 dom0; dom0 performed the I/O and wrote
directly into the grant-mapped memory and unmapped it; blkfront then
removed foreign access for that grant. The cost of unmapping scales
badly with the number of CPUs in Dom0. An experiment showed that when
Dom0 has 24 VCPUs, and guests are performing parallel I/O to a
ramdisk, the IPIs from performing unmap's is a bottleneck at 5 guests
(at which point 650,000 IOPS are being performed in total). If more
than 5 guests are used, the performance declines. By 10 guests, only
400,000 IOPS are being performed.
This patch improves performance by only unmapping when the connection
between blkfront and back is broken.
On startup blkfront notifies blkback that it is using persistent
grants, and blkback will do the same. If blkback is not capable of
persistent mapping, blkfront will still use the same grants, since it
is compatible with the previous protocol, and simplifies the code
complexity in blkfront.
To perform a read, in persistent mode, blkfront uses a separate pool
of pages that it maps to dom0. When a request comes in, blkfront
transmutes the request so that blkback will write into one of these
free pages. Blkback keeps note of which grefs it has already
mapped. When a new ring request comes to blkback, it looks to see if
it has already mapped that page. If so, it will not map it again. If
the page hasn't been previously mapped, it is mapped now, and a record
is kept of this mapping. Blkback proceeds as usual. When blkfront is
notified that blkback has completed a request, it memcpy's from the
shared memory, into the bvec supplied. A record that the {gref, page}
tuple is mapped, and not inflight is kept.
Writes are similar, except that the memcpy is peformed from the
supplied bvecs, into the shared pages, before the request is put onto
the ring.
Blkback stores a mapping of grefs=>{page mapped to by gref} in
a red-black tree. As the grefs are not known apriori, and provide no
guarantees on their ordering, we have to perform a search
through this tree to find the page, for every gref we receive. This
operation takes O(log n) time in the worst case. In blkfront grants
are stored using a single linked list.
The maximum number of grants that blkback will persistenly map is
currently set to RING_SIZE * BLKIF_MAX_SEGMENTS_PER_REQUEST, to
prevent a malicios guest from attempting a DoS, by supplying fresh
grefs, causing the Dom0 kernel to map excessively. If a guest
is using persistent grants and exceeds the maximum number of grants to
map persistenly the newly passed grefs will be mapped and unmaped.
Using this approach, we can have requests that mix persistent and
non-persistent grants, and we need to handle them correctly.
This allows us to set the maximum number of persistent grants to a
lower value than RING_SIZE * BLKIF_MAX_SEGMENTS_PER_REQUEST, although
setting it will lead to unpredictable performance.
In writing this patch, the question arrises as to if the additional
cost of performing memcpys in the guest (to/from the pool of granted
pages) outweigh the gains of not performing TLB shootdowns. The answer
to that question is `no'. There appears to be very little, if any
additional cost to the guest of using persistent grants. There is
perhaps a small saving, from the reduced number of hypercalls
performed in granting, and ending foreign access.
Signed-off-by: Oliver Chick <oliver.chick@citrix.com>
Signed-off-by: Roger Pau Monne <roger.pau@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[v1: Fixed up the misuse of bool as int]
flush[_delayed]_work_sync() are now spurious. Mark them deprecated
and convert all users to flush[_delayed]_work().
If you're cc'd and wondering what's going on: Now all workqueues are
non-reentrant and the regular flushes guarantee that the work item is
not pending or running on any CPU on return, so there's no reason to
use the sync flushes at all and they're going away.
This patch doesn't make any functional difference.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Mattia Dongili <malattia@linux.it>
Cc: Kent Yoder <key@linux.vnet.ibm.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: Bryan Wu <bryan.wu@canonical.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-wireless@vger.kernel.org
Cc: Anton Vorontsov <cbou@mail.ru>
Cc: Sangbeom Kim <sbkim73@samsung.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Petr Vandrovec <petr@vandrovec.name>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Avi Kivity <avi@redhat.com>
from interrupts for /dev/random and /dev/urandom. The goal is to
addresses weaknesses discussed in the paper "Mining your Ps and Qs:
Detection of Widespread Weak Keys in Network Devices", by Nadia
Heninger, Zakir Durumeric, Eric Wustrow, J. Alex Halderman, which will
be published in the Proceedings of the 21st Usenix Security Symposium,
August 2012. (See https://factorable.net for more information and an
extended version of the paper.)
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Merge tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random
Pull random subsystem patches from Ted Ts'o:
"This patch series contains a major revamp of how we collect entropy
from interrupts for /dev/random and /dev/urandom.
The goal is to addresses weaknesses discussed in the paper "Mining
your Ps and Qs: Detection of Widespread Weak Keys in Network Devices",
by Nadia Heninger, Zakir Durumeric, Eric Wustrow, J. Alex Halderman,
which will be published in the Proceedings of the 21st Usenix Security
Symposium, August 2012. (See https://factorable.net for more
information and an extended version of the paper.)"
Fix up trivial conflicts due to nearby changes in
drivers/{mfd/ab3100-core.c, usb/gadget/omap_udc.c}
* tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random: (33 commits)
random: mix in architectural randomness in extract_buf()
dmi: Feed DMI table to /dev/random driver
random: Add comment to random_initialize()
random: final removal of IRQF_SAMPLE_RANDOM
um: remove IRQF_SAMPLE_RANDOM which is now a no-op
sparc/ldc: remove IRQF_SAMPLE_RANDOM which is now a no-op
[ARM] pxa: remove IRQF_SAMPLE_RANDOM which is now a no-op
board-palmz71: remove IRQF_SAMPLE_RANDOM which is now a no-op
isp1301_omap: remove IRQF_SAMPLE_RANDOM which is now a no-op
pxa25x_udc: remove IRQF_SAMPLE_RANDOM which is now a no-op
omap_udc: remove IRQF_SAMPLE_RANDOM which is now a no-op
goku_udc: remove IRQF_SAMPLE_RANDOM which was commented out
uartlite: remove IRQF_SAMPLE_RANDOM which is now a no-op
drivers: hv: remove IRQF_SAMPLE_RANDOM which is now a no-op
xen-blkfront: remove IRQF_SAMPLE_RANDOM which is now a no-op
n2_crypto: remove IRQF_SAMPLE_RANDOM which is now a no-op
pda_power: remove IRQF_SAMPLE_RANDOM which is now a no-op
i2c-pmcmsp: remove IRQF_SAMPLE_RANDOM which is now a no-op
input/serio/hp_sdc.c: remove IRQF_SAMPLE_RANDOM which is now a no-op
mfd: remove IRQF_SAMPLE_RANDOM which is now a no-op
...
With the changes in the random tree, IRQF_SAMPLE_RANDOM is now a
no-op; interrupt randomness is now collected unconditionally in a very
low-overhead fashion; see commit 775f4b297b. The IRQF_SAMPLE_RANDOM
flag was scheduled to be removed in 2009 on the
feature-removal-schedule, so this patch is preparation for the final
removal of this flag.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Part of the ring structure is the 'id' field which is under
control of the frontend. The frontend stamps it with "some"
value (this some in this implementation being a value less
than BLK_RING_SIZE), and when it gets a response expects
said value to be in the response structure. We have a check
for the id field when spolling new requests but not when
de-spolling responses.
We also add an extra check in add_id_to_freelist to make
sure that the 'struct request' was not NULL - as we cannot
pass a NULL to __blk_end_request_all, otherwise that crashes
(and all the operations that the response is dealing with
end up with __blk_end_request_all).
Lastly we also print the name of the operation that failed.
[v1: s/BUG/WARN/ suggested by Stefano]
[v2: Add extra check in add_id_to_freelist]
[v3: Redid op_name per Jan's suggestion]
[v4: add const * and add WARN on failure returns]
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
The blkdev major must be released upon exit, or else the module can't
attach to devices using the same majors upon being loaded again. Also
avoid leaking the minor tracking bitmap.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
- devices beyond xvdzz didn't get proper names assigned at all
- extended devices with minors not representable within the kernel's
major/minor bit split spilled into foreign majors
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Pull block driver bits from Jens Axboe:
- A series of fixes for mtip32xx. Most from Asai at Micron, but also
one from Greg, getting rid of the dependency on PCIE_HOTPLUG.
- A few bug fixes for xen-blkfront, and blkback.
- A virtio-blk fix for Vivek, making resize actually work.
- Two fixes from Stephen, making larger transfers possible on cciss.
This is needed for tape drive support.
* 'for-3.4/drivers' of git://git.kernel.dk/linux-block:
block: mtip32xx: remove HOTPLUG_PCI_PCIE dependancy
mtip32xx: dump tagmap on failure
mtip32xx: fix handling of commands in various scenarios
mtip32xx: Shorten macro names
mtip32xx: misc changes
mtip32xx: Add new sysfs entry 'status'
mtip32xx: make setting comp_time as common
mtip32xx: Add new bitwise flag 'dd_flag'
mtip32xx: fix error handling in mtip_init()
virtio-blk: Call revalidate_disk() upon online disk resize
xen/blkback: Make optional features be really optional.
xen/blkback: Squash the discard support for 'file' and 'phy' type.
mtip32xx: fix incorrect value set for drv_cleanup_done, and re-initialize and start port in mtip_restart_port()
cciss: Fix scsi tape io with more than 255 scatter gather elements
cciss: Initialize scsi host max_sectors for tape drive support
xen-blkfront: make blkif_io_lock spinlock per-device
xen/blkfront: don't put bdev right after getting it
xen-blkfront: use bitmap_set() and bitmap_clear()
xen/blkback: Enable blkback on HVM guests
xen/blkback: use grant-table.c hypercall wrappers
* one is a workaround that will be removed in v3.5 with proper fix in the tip/x86 tree,
* the other is to fix drivers to load on PV (a previous patch made them only
load in PVonHVM mode).
The rest are just minor fixes in the various drivers and some cleanup in the
core code.
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Merge tag 'stable/for-linus-3.4-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
Pull xen fixes from Konrad Rzeszutek Wilk:
"Two fixes for regressions:
* one is a workaround that will be removed in v3.5 with proper fix in
the tip/x86 tree,
* the other is to fix drivers to load on PV (a previous patch made
them only load in PVonHVM mode).
The rest are just minor fixes in the various drivers and some cleanup
in the core code."
* tag 'stable/for-linus-3.4-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
xen/pcifront: avoid pci_frontend_enable_msix() falsely returning success
xen/pciback: fix XEN_PCI_OP_enable_msix result
xen/smp: Remove unnecessary call to smp_processor_id()
xen/x86: Workaround 'x86/ioapic: Add register level checks to detect bogus io-apic entries'
xen: only check xen_platform_pci_unplug if hvm
commit b9136d207f08
xen: initialize platform-pci even if xen_emul_unplug=never
breaks blkfront/netfront by not loading them because of
xen_platform_pci_unplug=0 and it is never set for PV guest.
Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* Add fast-EOI acking of interrupts (clear a bit instead of hypercall)
And bug-fixes:
* Fix CPU bring-up code missing a call to notify other subsystems.
* Fix reading /sys/hypervisor even if PVonHVM drivers are not loaded.
* In Xen ACPI processor driver: remove too verbose WARN messages, fix up
the Kconfig dependency to be a module by default, and add dependency on
CPU_FREQ.
* Disable CPU frequency drivers from loading when booting under Xen
(as we want the Xen ACPI processor to be used instead).
* Cleanups in tmem code.
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Merge tag 'stable/for-linus-3.4-tag-two' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
Pull more xen updates from Konrad Rzeszutek Wilk:
"One tiny feature that accidentally got lost in the initial git pull:
* Add fast-EOI acking of interrupts (clear a bit instead of
hypercall)
And bug-fixes:
* Fix CPU bring-up code missing a call to notify other subsystems.
* Fix reading /sys/hypervisor even if PVonHVM drivers are not loaded.
* In Xen ACPI processor driver: remove too verbose WARN messages, fix
up the Kconfig dependency to be a module by default, and add
dependency on CPU_FREQ.
* Disable CPU frequency drivers from loading when booting under Xen
(as we want the Xen ACPI processor to be used instead).
* Cleanups in tmem code."
* tag 'stable/for-linus-3.4-tag-two' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
xen/acpi: Fix Kconfig dependency on CPU_FREQ
xen: initialize platform-pci even if xen_emul_unplug=never
xen/smp: Fix bringup bug in AP code.
xen/acpi: Remove the WARN's as they just create noise.
xen/tmem: cleanup
xen: support pirq_eoi_map
xen/acpi-processor: Do not depend on CPU frequency scaling drivers.
xen/cpufreq: Disable the cpu frequency scaling drivers from loading.
provide disable_cpufreq() function to disable the API.
When xen_emul_unplug=never is specified on kernel command line
reading files from /sys/hypervisor is broken (returns -EBUSY).
It is caused by xen_bus dependency on platform-pci and
platform-pci isn't initialized when xen_emul_unplug=never is
specified.
Fix it by allowing platform-pci to ignore xen_emul_unplug=never,
and do not intialize xen_[blk|net]front instead.
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This patch moves the global blkif_io_lock to the per-device structure. The
spinlock seems to exists for two reasons: to disable IRQs when in the interrupt
handlers for blkfront, and to protect the blkfront VBDs when a detachment is
requested.
Having a global blkif_io_lock doesn't make sense given the use case, and it
drastically hinders performance due to contention. All VBDs with pending IOs
have to take the lock in order to get work done, which serializes everything
pretty badly.
Signed-off-by: Steven Noonan <snoonan@amazon.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
We should hang onto bdev until we're done with it.
Signed-off-by: Andrew Jones <drjones@redhat.com>
[v1: Fixed up git commit description]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Use bitmap_set and bitmap_clear rather than modifying individual bits
in a memory region.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: xen-devel@lists.xensource.com
Cc: virtualization@lists.linux-foundation.org
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* 'for-3.3/drivers' of git://git.kernel.dk/linux-block:
mtip32xx: do rebuild monitoring asynchronously
xen-blkfront: Use kcalloc instead of kzalloc to allocate array
mtip32xx: uninitialized variable in mtip_quiesce_io()
mtip32xx: updates based on feedback
xen-blkback: convert hole punching to discard request on loop devices
xen/blkback: Move processing of BLKIF_OP_DISCARD from dispatch_rw_block_io
xen/blk[front|back]: Enhance discard support with secure erasing support.
xen/blk[front|back]: Squash blkif_request_rw and blkif_request_discard together
mtip32xx: update to new ->make_request() API
mtip32xx: add module.h include to avoid conflict with moduleh tree
mtip32xx: mark a few more items static
mtip32xx: ensure that all local functions are static
mtip32xx: cleanup compat ioctl handling
mtip32xx: fix warnings/errors on 32-bit compiles
block: Add driver for Micron RealSSD pcie flash cards
The 'name', 'owner', and 'mod_name' members are redundant with the
identically named fields in the 'driver' sub-structure. Rather than
switching each instance to specify these fields explicitly, introduce
a macro to simplify this.
Eliminate further redundancy by allowing the drvname argument to
DEFINE_XENBUS_DRIVER() to be blank (in which case the first entry from
the ID table will be used for .driver.name).
Also eliminate the questionable xenbus_register_{back,front}end()
wrappers - their sole remaining purpose was the checking of the
'owner' field, proper setting of which shouldn't be an issue anymore
when the macro gets used.
v2: Restore DRV_NAME for the driver name in xen-pciback.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
The advantage of kcalloc is, that will prevent integer overflows which could
result from the multiplication of number of elements and size and it is also
a bit nicer to read.
The semantic patch that makes this change is available
in https://lkml.org/lkml/2011/11/25/107
Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
[v1: Seperated the drivers/block/cciss_scsi.c out of this patch]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Part of the blkdev_issue_discard(xx) operation is that it can also
issue a secure discard operation that will permanantly remove the
sectors in question. We advertise that we can support that via the
'discard-secure' attribute and on the request, if the 'secure' bit
is set, we will attempt to pass in REQ_DISCARD | REQ_SECURE.
CC: Li Dongyang <lidongyang@novell.com>
[v1: Used 'flag' instead of 'secure:1' bit]
[v2: Use 'reserved' uint8_t instead of adding a new value]
[v3: Check for nseg when mapping instead of operation]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
In a union type structure to deal with the overlapping
attributes in a easier manner.
Suggested-by: Ian Campbell <Ian.Campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* 'for-3.2/drivers' of git://git.kernel.dk/linux-block: (30 commits)
virtio-blk: use ida to allocate disk index
hpsa: add small delay when using PCI Power Management to reset for kump
cciss: add small delay when using PCI Power Management to reset for kump
xen/blkback: Fix two races in the handling of barrier requests.
xen/blkback: Check for proper operation.
xen/blkback: Fix the inhibition to map pages when discarding sector ranges.
xen/blkback: Report VBD_WSECT (wr_sect) properly.
xen/blkback: Support 'feature-barrier' aka old-style BARRIER requests.
xen-blkfront: plug device number leak in xlblk_init() error path
xen-blkfront: If no barrier or flush is supported, use invalid operation.
xen-blkback: use kzalloc() in favor of kmalloc()+memset()
xen-blkback: fixed indentation and comments
xen-blkfront: fix a deadlock while handling discard response
xen-blkfront: Handle discard requests.
xen-blkback: Implement discard requests ('feature-discard')
xen-blkfront: add BLKIF_OP_DISCARD and discard request struct
drivers/block/loop.c: remove unnecessary bdev argument from loop_clr_fd()
drivers/block/loop.c: emit uevent on auto release
drivers/block/cpqarray.c: use pci_dev->revision
loop: always allow userspace partitions and optionally support automatic scanning
...
Fic up trivial header file includsion conflict in drivers/block/loop.c
... though after a failed xenbus_register_frontend() all may be lost.
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Guard against issuing BLKIF_OP_WRITE_BARRIER or BLKIF_OP_FLUSH_CACHE
by checking whether we successfully negotiated with the backend.
The negotiation with the backend also sets the q->flush_flags which
fortunately for us is also used when submitting an bio to us. If
we don't support barriers or flushes it would be set to zero so
we should never end up having to deal with REQ_FLUSH | REQ_FUA.
However, other third party implementations of __make_request that
might be stacked on top of us might not be so smart, so lets fix this up.
Acked-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
When we get -EOPNOTSUPP response for a discard request, we will clear
the discard flag on the request queue so we won't attempt to send discard
requests to backend again, and this should be protected under rq->queue_lock.
However, when we setup the request queue, we pass blkif_io_lock to
blk_init_queue so rq->queue_lock is blkif_io_lock indeed, and this lock
is already taken when we are in blkif_interrpt, so remove the
spin_lock/spin_unlock when we clear the discard flag or we will end up
with deadlock here
Signed-off-by: Li Dongyang <lidongyang@novell.com>
[v1: Updated description a bit and removed comment from source]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
If the backend advertises 'feature-discard', then interrogate
the backend for alignment and granularity. Setup the request
queue with the appropiate values and send the discard operation
as required.
Signed-off-by: Li Dongyang <lidongyang@novell.com>
[v1: Amended commit description]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Avoid telling users to use xvde and onwards when using xvde.
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
These were intended to avoid the namespace clash when representing
emulated IDE and SCSI devices. However that seems to confuse users
more than expected (a disk defined as sda becomes xvde).
So for now go back to the scheme which does no adjustments. This
will break when mixing IDE and SCSI names in the configuration of
guests but should be by now expected.
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
If the backend supports the 'feature-flush-cache' mode, use that
instead of the 'feature-barrier' support.
Currently there are three backends that support the 'feature-flush-cache'
mode: NetBSD, Solaris and Linux kernel. The 'flush' option is much
light-weight version than the 'barrier' support so lets try to use as
there are no filesystems in the kernel that use full barriers anymore.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
barrier variable is int, not long. This overflow caused another variable
override: "err" (in PV code) and "binfo" (in xenlinux code -
drivers/xen/blkfront/blkfront.c). The later caused incorrect device
flags (RO/removable etc).
Signed-off-by: Marek Marczykowski <marmarek@mimuw.edu.pl>
Acked-by: Ian Campbell <Ian.Campbell@citrix.com>
[v1: Changed title]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* 'for-linus' of git://xenbits.xen.org/people/sstabellini/linux-pvhvm:
xen: suspend: remove xen_hvm_suspend
xen: suspend: pull pre/post suspend hooks out into suspend_info
xen: suspend: move arch specific pre/post suspend hooks into generic hooks
xen: suspend: refactor non-arch specific pre/post suspend hooks
xen: suspend: add "arch" to pre/post suspend hooks
xen: suspend: pass extra hypercall argument via suspend_info struct
xen: suspend: refactor cancellation flag into a structure
xen: suspend: use HYPERVISOR_suspend for PVHVM case instead of open coding
xen: switch to new schedop hypercall by default.
xen: use new schedop interface for suspend
xen: do not respond to unknown xenstore control requests
xen: fix compile issue if XEN is enabled but XEN_PVHVM is disabled
xen: PV on HVM: support PV spinlocks and IPIs
xen: make the ballon driver work for hvm domains
xen-blkfront: handle Xen major numbers other than XENVBD
xen: do not use xen_info on HVM, set pv_info name to "Xen HVM"
xen: no need to delay xen_setup_shutdown_event for hvm guests anymore
Prepare for extending the block device ring to allow request
specific fields, by moving the request specific fields for
reads, writes and barrier requests to a union member.
Acked-by: Jens Axboe <jaxboe@fusionio.com>
Signed-off-by: Owen Smith <owen.smith@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This patch makes sure blkfront handles correctly virtual device numbers
corresponding to Xen emulated IDE and SCSI disks: in those cases
blkfront translates the major number to XENVBD and the minor number to a
low xvd minor.
Note: this behaviour is different from what old xenlinux PV guests used
to do: they used to steal an IDE or SCSI major number and use it
instead.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
