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2018-07-02hw/xen: Use the IEC binary prefix definitionsPhilippe Mathieu-Daudé1-1/+2
It eases code review, unit is explicit. Patch generated using: $ git grep -E '(1024|2048|4096|8192|(<<|>>).?(10|20|30))' hw/ include/hw/ and modified manually. Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Reviewed-by: Alan Robinson <Alan.Robinson@ts.fujitsu.com> Message-Id: <20180625124238.25339-12-f4bug@amsat.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-05-22xen_disk: be consistent with use of xendev and blkdev->xendevPaul Durrant1-44/+46
Certain functions in xen_disk are called with a pointer to xendev (struct XenDevice *). They then use container_of() to acces the surrounding blkdev (struct XenBlkDev) but then in various places use &blkdev->xendev when use of the original xendev pointer is shorter to express and clearly equivalent. This patch is a purely cosmetic patch which makes sure there is a xendev pointer on stack for any function where the pointer is need on multiple occasions modified those functions to use it consistently. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Acked-by: Anthony PERARD <anthony.perard@citrix.com> Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
2018-05-22xen_disk: use a single entry iovecPaul Durrant1-55/+21
Since xen_disk now always copies data to and from a guest there is no need to maintain a vector entry corresponding to every page of a request. This means there is less per-request state to maintain so the ioreq structure can shrink significantly. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Acked-by: Anthony Perard <anthony.perard@citrix.com> Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
2018-05-22xen_disk: remove use of grant map/unmapPaul Durrant1-327/+25
Now that the (native or emulated) xen_be_copy_grant_refs() helper is always available, the xen_disk code can be significantly simplified by removing direct use of grant map and unmap operations. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Acked-by: Anthony Perard <anthony.perard@citrix.com> Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
2018-05-22xen_disk: remove open-coded use of libxengnttabPaul Durrant1-90/+32
Now that helpers are present in xen_backend, this patch removes open-coded calls to libxengnttab from the xen_disk code. This patch also fixes one whitspace error in the assignment of the XenDevOps initialise method. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Acked-by: Anthony Perard <anthony.perard@citrix.com> Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
2018-05-22xen: add a meaningful declaration of grant_copy_segment into xen_common.hPaul Durrant1-18/+0
Currently the xen_disk source has to carry #ifdef exclusions to compile against Xen older then 4.8. This is a bit messy so this patch lifts the definition of struct xengnttab_grant_copy_segment and adds it into the pre-4.8 compat area in xen_common.h, which allows xen_disk to be cleaned up. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Acked-by: Anthony PERARD <anthony.perard@citrix.com> Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
2017-12-14xen-disk: use an IOThread per instancePaul Durrant1-7/+46
This patch allocates an IOThread object for each xen_disk instance and sets the AIO context appropriately on connect. This allows processing of I/O to proceed in parallel. The patch also adds tracepoints into xen_disk to make it possible to follow the state transtions of an instance in the log. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Acked-by: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
2017-10-26xen: dont try setting max grants multiple timesJuergen Gross1-4/+12
Trying to call xengnttab_set_max_grants() with the same file handle might fail on some kernels, as this operation is allowed only once. This is a problem for the qdisk backend as blk_connect() can be called multiple times for a domain, e.g. in case grub-xen is being used to boot it. So instead of letting the generic backend code open the gnttab device do it in blk_connect() and close it again in blk_disconnect. Signed-off-by: Juergen Gross <jgross@suse.com> Acked-by: Anthony PERARD <anthony.perard@citrix.com> Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
2017-10-26xen: add a global indicator for grant copy being availableJuergen Gross1-12/+6
The Xen qdisk backend needs to test whether grant copy operations is available in the kernel. Unfortunately this collides with using xengnttab_set_max_grants() on some kernels as this operation has to be the first one after opening the gnttab device. In order to solve this problem test for the availability of grant copy in xen_be_init() opening the gnttab device just for that purpose and closing it again afterwards. Advertise the availability via a global flag and use that flag in the qdisk backend. Signed-off-by: Juergen Gross <jgross@suse.com> Acked-by: Anthony PERARD <anthony.perard@citrix.com> Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
2017-09-20xen-disk: use g_new0 to fix buildOlaf Hering1-1/+1
g_malloc0_n is available since glib-2.24. To allow build with older glib versions use the generic g_new0, which is already used in many other places in the code. Fixes commit 3284fad728 ("xen-disk: add support for multi-page shared rings") Signed-off-by: Olaf Hering <olaf@aepfle.de> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
2017-06-27xen-disk: add support for multi-page shared ringsPaul Durrant1-31/+113
The blkif protocol has had provision for negotiation of multi-page shared rings for some time now and many guest OS have support in their frontend drivers. This patch makes the necessary modifications to xen-disk support a shared ring up to order 4 (i.e. 16 pages). Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Signed-off-by: Stefano Stabellini <sstabellini@kernel.org> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
2017-06-27xen-disk: only advertize feature-persistent if grant copy is not availablePaul Durrant1-7/+8
If grant copy is available then it will always be used in preference to persistent maps. In this case feature-persistent should not be advertized to the frontend, otherwise it may needlessly copy data into persistently granted buffers. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Signed-off-by: Stefano Stabellini <sstabellini@kernel.org> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
2017-06-27xen/disk: don't leak stack data via response ringStefano Stabellini1-13/+12
Rather than constructing a local structure instance on the stack, fill the fields directly on the shared ring, just like other (Linux) backends do. Build on the fact that all response structure flavors are actually identical (aside from alignment and padding at the end). This is XSA-216. Reported by: Anthony Perard <anthony.perard@citrix.com> Signed-off-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Stefano Stabellini <sstabellini@kernel.org> Acked-by: Anthony PERARD <anthony.perard@citrix.com>
2017-05-09qobject: Use simpler QDict/QList scalar insertion macrosEric Blake1-1/+1
We now have macros in place to make it less verbose to add a scalar to QDict and QList, so use them. Patch created mechanically via: spatch --sp-file scripts/coccinelle/qobject.cocci \ --macro-file scripts/cocci-macro-file.h --dir . --in-place then touched up manually to fix a couple of '?:' back to original spacing, as well as avoiding a long line in monitor.c. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20170427215821.19397-7-eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-04-21xen: use 5 digit xen versionsJuergen Gross1-1/+1
Today qemu is using e.g. the value 480 for Xen version 4.8.0. As some Xen version tests are using ">" relations this scheme will lead to problems when Xen version 4.10.0 is being reached. Instead of the 3 digit schem use a 5 digit scheme (e.g. 40800 for version 4.8.0). Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Stefano Stabellini <sstabellini@kernel.org> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
2016-11-23xen_disk: split discard input to match internal representationOlaf Hering1-6/+36
The guest sends discard requests as u64 sector/count pairs, but the block layer operates internally with s64/s32 pairs. The conversion leads to IO errors in the guest, the discard request is not processed. domU.cfg: 'vdev=xvda, format=qcow2, backendtype=qdisk, target=/x.qcow2' domU: mkfs.ext4 -F /dev/xvda Discarding device blocks: failed - Input/output error Fix this by splitting the request into chunks of BDRV_REQUEST_MAX_SECTORS. Add input range checking to avoid overflow. Fixes f313520 ("xen_disk: add discard support") Signed-off-by: Olaf Hering <olaf@aepfle.de> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
2016-10-28xen: Rename xen_be_send_notifyEmil Condrea1-2/+2
Prepare xen_be_send_notify to be shared with frontends: * xen_be_send_notify -> xen_pv_send_notify Signed-off-by: Emil Condrea <emilcondrea@gmail.com> Signed-off-by: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: Quan Xu <xuquan8@huawei.com> Acked-by: Anthony PERARD <anthony.perard@citrix.com>
2016-10-28xen: Rename xen_be_unbind_evtchnEmil Condrea1-1/+1
Prepare xen_be_unbind_evtchn to be shared with frontends: * xen_be_unbind_evtchn -> xen_pv_unbind_evtchn Signed-off-by: Emil Condrea <emilcondrea@gmail.com> Signed-off-by: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: Quan Xu <xuquan8@huawei.com> Acked-by: Anthony PERARD <anthony.perard@citrix.com>
2016-10-28xen: Rename xen_be_printf to xen_pv_printfEmil Condrea1-29/+29
Prepare xen_be_printf to be used by both backend and frontends: * xen_be_printf -> xen_pv_printf Signed-off-by: Emil Condrea <emilcondrea@gmail.com> Signed-off-by: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: Quan Xu <xuquan8@huawei.com> Acked-by: Anthony PERARD <anthony.perard@citrix.com>
2016-10-28xen: Fix coding style warningsEmil Condrea1-1/+2
Fixes: * WARNING: line over 80 characters Signed-off-by: Emil Condrea <emilcondrea@gmail.com> Signed-off-by: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: Quan Xu <xuquan8@huawei.com> Acked-by: Anthony PERARD <anthony.perard@citrix.com>
2016-10-07block-backend: Remember if attached device is non-qdevKevin Wolf1-1/+1
Almost all block devices are qdevified by now. This allows us to go back from the BlockBackend to the DeviceState. xen_disk is the last device that is missing. We'll remember in the BlockBackend if a xen_disk is attached and can then disable any features that require going from a BB to the DeviceState. While at it, clearly mark the function used by xen_disk as legacy even in its name, not just in TODO comments. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-09-27qdisk - hw/block/xen_disk: grant copy implementationPaulina Szubarczyk1-5/+148
Copy data operated on during request from/to local buffers to/from the grant references. Before grant copy operation local buffers must be allocated what is done by calling ioreq_init_copy_buffers. For the 'read' operation, first, the qemu device invokes the read operation on local buffers and on the completion grant copy is called and buffers are freed. For the 'write' operation grant copy is performed before invoking write by qemu device. A new value 'feature_grant_copy' is added to recognize when the grant copy operation is supported by a guest. Signed-off-by: Paulina Szubarczyk <paulinaszubarczyk@gmail.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Acked-by: Anthony PERARD <anthony.perard@citrix.com> Acked-by: Roger Pau Monné <roger.pau@citrix.com>
2016-08-30xen: use native disk xenbus protocol if possibleJuergen Gross1-8/+10
The qdisk implementation is using the native xenbus protocol only in case of no protocol specified at all. As using the explicit 32- or 64-bit protocol is slower than the native one due to copying requests not by memcpy but element for element, this is not optimal. Correct this by using the native protocol in case word sizes of frontend and backend match. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Anthony PERARD <anthony.perard@citrix.com> Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
2016-07-20block: Convert BB interface to byte-based discardsEric Blake1-3/+4
Change sector-based blk_discard(), blk_co_discard(), and blk_aio_discard() to instead be byte-based blk_pdiscard(), blk_co_pdiscard(), and blk_aio_pdiscard(). NBD gets a lot simpler now that ignoring the unaligned portion of a byte-based discard request is handled under the hood by the block layer. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 1468624988-423-6-git-send-email-eblake@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-06-16os-posix: include sys/mman.hPaolo Bonzini1-1/+0
qemu/osdep.h checks whether MAP_ANONYMOUS is defined, but this check is bogus without a previous inclusion of sys/mman.h. Include it in sysemu/os-posix.h and remove it from everywhere else. Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-13xen/blkif: avoid double access to any shared ring request fieldsJan Beulich1-0/+2
Commit f9e98e5d7a ("xen/blkif: Avoid double access to src->nr_segments") didn't go far enough: src->operation is also being used twice. And nothing was done to prevent the compiler from using the source side of the copy done by blk_get_request() (granted that's very unlikely). Move the barrier()s up, and add another one to blk_get_request(). Note that for completing XSA-155, the barrier() getting added to blk_get_request() would suffice, and hence the changes to xen_blkif.h are more like just cleanup. And since, as said, the unpatched code getting compiled to something vulnerable is very unlikely (and not observed in practice), this isn't being viewed as a new security issue. Signed-off-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
2016-05-12xen_disk: Switch to byte-based aio block accessEric Blake1-6/+4
Sector-based blk_aio_readv() and blk_aio_writev() should die; switch to byte-based blk_aio_preadv() and blk_aio_pwritev() instead. Signed-off-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-03-30xen_disk: Call blk_set_enable_write_cache() explicitlyKevin Wolf1-1/+4
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-03-22include/qemu/osdep.h: Don't include qapi/error.hMarkus Armbruster1-0/+1
Commit 57cb38b included qapi/error.h into qemu/osdep.h to get the Error typedef. Since then, we've moved to include qemu/osdep.h everywhere. Its file comment explains: "To avoid getting into possible circular include dependencies, this file should not include any other QEMU headers, with the exceptions of config-host.h, compiler.h, os-posix.h and os-win32.h, all of which are doing a similar job to this file and are under similar constraints." qapi/error.h doesn't do a similar job, and it doesn't adhere to similar constraints: it includes qapi-types.h. That's in excess of 100KiB of crap most .c files don't actually need. Add the typedef to qemu/typedefs.h, and include that instead of qapi/error.h. Include qapi/error.h in .c files that need it and don't get it now. Include qapi-types.h in qom/object.h for uint16List. Update scripts/clean-includes accordingly. Update it further to match reality: replace config.h by config-target.h, add sysemu/os-posix.h, sysemu/os-win32.h. Update the list of includes in the qemu/osdep.h comment quoted above similarly. This reduces the number of objects depending on qapi/error.h from "all of them" to less than a third. Unfortunately, the number depending on qapi-types.h shrinks only a little. More work is needed for that one. Signed-off-by: Markus Armbruster <armbru@redhat.com> [Fix compilation without the spice devel packages. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-17blockdev: Split monitor reference from BB creationMax Reitz1-1/+1
Before this patch, blk_new() automatically assigned a name to the new BlockBackend and considered it referenced by the monitor. This patch removes the implicit monitor_add_blk() call from blk_new() (and consequently the monitor_remove_blk() call from blk_delete(), too) and thus blk_new() (and related functions) no longer take a BB name argument. In fact, there is only a single point where blk_new()/blk_new_open() is called and the new BB is monitor-owned, and that is in blockdev_init(). Besides thus relieving us from having to invent names for all of the BBs we use in qemu-img, this fixes a bug where qemu cannot create a new image if there already is a monitor-owned BB named "image". If a BB and its BDS tree are created in a single operation, as of this patch the BDS tree will be created before the BB is given a name (whereas it was the other way around before). This results in minor change to the output of iotest 087, whose reference output is amended accordingly. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-01-26xen: Switch to libxengnttab interface for compat shims.Ian Campbell1-18/+20
In Xen 4.7 we are refactoring parts libxenctrl into a number of separate libraries which will provide backward and forward API and ABI compatiblity. One such library will be libxengnttab which provides access to grant tables. In preparation for this switch the compatibility layer in xen_common.h (which support building with older versions of Xen) to use what will be the new library API. This means that the gnttab shim will disappear for versions of Xen which include libxengnttab. To simplify things for the <= 4.0.0 support we wrap the int fd in a malloc(sizeof int) such that the handle is always a pointer. This leads to less typedef headaches and the need for XC_HANDLER_INITIAL_VALUE etc for these interfaces. Note that this patch does not add any support for actually using libxengnttab, it just adjusts the existing shims. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2016-01-20block: Clean up includesPeter Maydell1-11/+1
Clean up includes so that osdep.h is included first and headers which it implies are not included manually. This commit was created with scripts/clean-includes. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-12-11xen_disk: treat "vhd" as "vpc"Stefano Stabellini1-0/+3
The Xen toolstack uses "vhd" to specify a disk in VHD format, however the name of the driver in QEMU is "vpc". Replace "vhd" with "vpc", so that QEMU can find the right driver to use for it. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2015-11-25xen_disk: Remove ioreq.postsyncAlberto Garcia1-8/+0
This code has been dead for three years (since commit 7e7b7cba1). Signed-off-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2015-11-12xen_disk: Account for failed and invalid operationsAlberto Garcia1-1/+22
Signed-off-by: Alberto Garcia <berto@igalia.com> Message-id: e0cbb96cb0e1f86c37c7ce332efdf02b57b9d365.1446044838.git.berto@igalia.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-11-12xen_disk: Account for flush operationsAlberto Garcia1-1/+3
Currently both BLKIF_OP_WRITE and BLKIF_OP_FLUSH_DISKCACHE are being accounted as write operations. Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 7a2a14e3ac62027aa6267a6c02abc70717be9c0a.1446044837.git.berto@igalia.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-10-23block: Prepare for NULL BDSMax Reitz1-1/+3
blk_bs() will not necessarily return a non-NULL value any more (unless blk_is_available() is true or it can be assumed to otherwise, e.g. because it is called immediately after a successful blk_new_with_bs() or blk_new_open()). Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-09-11maint: remove unused include for signal.hDaniel P. Berrange1-1/+0
A number of files were including signal.h but not using any of the functions it provides Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2015-02-16block/xen: Use blk_new_open() in blk_connect()Max Reitz1-16/+11
As part of the required changes, this fixes a bug where specifying an invalid driver would result in the block layer probing the image format; now it will result in an error, unless "<unset>" is specified as the driver name. Fixing this would require further work on the xen_disk code which does not seem worth it (at this point and for this patch). Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 1423162705-32065-7-git-send-email-mreitz@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-11-14xen_disk: fix unmapping of persistent grantsRoger Pau Monne1-6/+66
This patch fixes two issues with persistent grants and the disk PV backend (Qdisk): - Keep track of memory regions where persistent grants have been mapped since we need to unmap them as a whole. It is not possible to unmap a single grant if it has been batch-mapped. A new check has also been added to make sure persistent grants are only used if the whole mapped region can be persistently mapped in the batch_maps case. - Unmap persistent grants before switching to the closed state, so the frontend can also free them. Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Reported-by: George Dunlap <george.dunlap@eu.citrix.com> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Cc: Kevin Wolf <kwolf@redhat.com> Cc: Stefan Hajnoczi <stefanha@redhat.com> Cc: George Dunlap <george.dunlap@eu.citrix.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2014-10-20hw: Convert from BlockDriverState to BlockBackend, mostlyMarkus Armbruster1-35/+34
Device models should access their block backends only through the block-backend.h API. Convert them, and drop direct includes of inappropriate headers. Just four uses of BlockDriverState are left: * The Xen paravirtual block device backend (xen_disk.c) opens images itself when set up via xenbus, bypassing blockdev.c. I figure it should go through qmp_blockdev_add() instead. * Device model "usb-storage" prompts for keys. No other device model does, and this one probably shouldn't do it, either. * ide_issue_trim_cb() uses bdrv_aio_discard() instead of blk_aio_discard() because it fishes its backend out of a BlockAIOCB, which has only the BlockDriverState. * PC87312State has an unused BlockDriverState[] member. The next two commits take care of the latter two. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20block: Eliminate DriveInfo member bdrv, use blk_by_legacy_dinfo()Markus Armbruster1-1/+1
The patch is big, but all it really does is replacing dinfo->bdrv by blk_bs(blk_by_legacy_dinfo(dinfo)) The replacement is repetitive, but the conversion of device models to BlockBackend is imminent, and will shorten it to just blk_legacy_dinfo(dinfo). Line wrapping muddies the waters a bit. I also omit tests whether dinfo->bdrv is null, because it never is. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Benoît Canet <benoit.canet@nodalink.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20block: Make BlockBackend own its BlockDriverStateMarkus Armbruster1-3/+3
On BlockBackend destruction, unref its BlockDriverState. Replaces the callers' unrefs. This turns the pointer from BlockBackend to BlockDriverState into a strong reference, managed with bdrv_ref() / bdrv_unref(). The back-pointer remains weak. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20block: Connect BlockBackend to BlockDriverStateMarkus Armbruster1-6/+2
Convenience function blk_new_with_bs() creates a BlockBackend with its BlockDriverState. Callers have to unref both. The commit after next will relieve them of the need to unref the BlockDriverState. Complication: due to the silly way drive_del works, we need a way to hide a BlockBackend, just like bdrv_make_anon(). To emphasize its "special" status, give the function a suitably off-putting name: blk_hide_on_behalf_of_do_drive_del(). Unfortunately, hiding turns the BlockBackend's name into the empty string. Can't avoid that without breaking the blk->bs->device_name equals blk->name invariant. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20block: New BlockBackendMarkus Armbruster1-0/+11
A block device consists of a frontend device model and a backend. A block backend has a tree of block drivers doing the actual work. The tree is managed by the block layer. We currently use a single abstraction BlockDriverState both for tree nodes and the backend as a whole. Drawbacks: * Its API includes both stuff that makes sense only at the block backend level (root of the tree) and stuff that's only for use within the block layer. This makes the API bigger and more complex than necessary. Moreover, it's not obvious which interfaces are meant for device models, and which really aren't. * Since device models keep a reference to their backend, the backend object can't just be destroyed. But for media change, we need to replace the tree. Our solution is to make the BlockDriverState generic, with actual driver state in a separate object, pointed to by member opaque. That lets us replace the tree by deinitializing and reinitializing its root. This special need of the root makes the data structure awkward everywhere in the tree. The general plan is to separate the APIs into "block backend", for use by device models, monitor and whatever other code dealing with block backends, and "block driver", for use by the block layer and whatever other code (if any) dealing with trees and tree nodes. Code dealing with block backends, device models in particular, should become completely oblivious of BlockDriverState. This should let us clean up both APIs, and the tree data structures. This commit is a first step. It creates a minimal "block backend" API: type BlockBackend and functions to create, destroy and find them. BlockBackend objects are created and destroyed exactly when root BlockDriverState objects are created and destroyed. "Root" in the sense of "in bdrv_states". They're not yet used for anything; that'll come shortly. A root BlockDriverState is created with bdrv_new_root(), so where to create a BlockBackend is obvious. Where these roots get destroyed isn't always as obvious. It is obvious in qemu-img.c, qemu-io.c and qemu-nbd.c, and in error paths of blockdev_init(), blk_connect(). That leaves destruction of objects successfully created by blockdev_init() and blk_connect(). blockdev_init() is used only by drive_new() and qmp_blockdev_add(). Objects created by the latter are currently indestructible (see commit 48f364d "blockdev: Refuse to drive_del something added with blockdev-add" and commit 2d246f0 "blockdev: Introduce DriveInfo.enable_auto_del"). Objects created by the former get destroyed by drive_del(). Objects created by blk_connect() get destroyed by blk_disconnect(). BlockBackend is reference-counted. Its reference count never exceeds one so far, but that's going to change. In drive_del(), the BB's reference count is surely one now. The BDS's reference count is greater than one when something else is holding a reference, such as a block job. In this case, the BB is destroyed right away, but the BDS lives on until all extra references get dropped. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20block: Split bdrv_new_root() off bdrv_new()Markus Armbruster1-1/+1
Creating an anonymous BDS can't fail. Make that obvious. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Benoît Canet <benoit.canet@nodalink.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-09-10block: Make the block accounting functions operate on BlockAcctStatsBenoît Canet1-5/+5
This is the next step for decoupling block accounting functions from BlockDriverState. In a future commit the BlockAcctStats structure will be moved from BlockDriverState to the device models structures. Note that bdrv_get_stats was introduced so device models can retrieve the BlockAcctStats structure of a BlockDriverState without being aware of it's layout. This function should go away when BlockAcctStats will be embedded in the device models structures. CC: Kevin Wolf <kwolf@redhat.com> CC: Stefan Hajnoczi <stefanha@redhat.com> CC: Keith Busch <keith.busch@intel.com> CC: Anthony Liguori <aliguori@amazon.com> CC: "Michael S. Tsirkin" <mst@redhat.com> CC: Paolo Bonzini <pbonzini@redhat.com> CC: Eric Blake <eblake@redhat.com> CC: Peter Maydell <peter.maydell@linaro.org> CC: Michael Tokarev <mjt@tls.msk.ru> CC: John Snow <jsnow@redhat.com> CC: Markus Armbruster <armbru@redhat.com> CC: Alexander Graf <agraf@suse.de> CC: Max Reitz <mreitz@redhat.com> Signed-off-by: Benoît Canet <benoit.canet@nodalink.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-09-10block: rename BlockAcctType members to start with BLOCK_ instead of BDRV_Benoît Canet1-2/+4
The middle term goal is to move the BlockAcctStats structure in the device models. (Capturing I/O accounting statistics in the device models is good for billing) This patch make a small step in this direction by removing a reference to BDRV. CC: Kevin Wolf <kwolf@redhat.com> CC: Stefan Hajnoczi <stefanha@redhat.com> CC: Keith Busch <keith.busch@intel.com> CC: Anthony Liguori <aliguori@amazon.com> CC: "Michael S. Tsirkin" <mst@redhat.com> CC: Paolo Bonzini <pbonzini@redhat.com> CC: John Snow <jsnow@redhat.com> CC: Richard Henderson <rth@twiddle.net> CC: Markus Armbruster <armbru@redhat.com> CC: Alexander Graf <agraf@suse.de>i Signed-off-by: Benoît Canet <benoit.canet@nodalink.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-09-10xen_disk: Plug memory leak on error pathMarkus Armbruster1-17/+14
The Error object was leaked after failed bdrv_new(). While there, streamline control flow a bit. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-08-15xen_disk: fix possible null-ptr dereferenceGonglei (Arei)1-0/+1
Signed-off-by: Gonglei <arei.gonglei@huawei.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
generated by cgit v1.1 at 2024-11-03 08:27:22 +0000