Commit Graph

519 Commits

Author SHA1 Message Date
Philippe Mathieu-Daudé e6b99460b1 hw/9pfs: Fix Kconfig dependency problem between 9pfs and Xen
Commit b2c00bce54 ("meson: convert hw/9pfs, cleanup") introduced
CONFIG_9PFS (probably a wrong conflict resolution). This config is
not used anywhere. Backends depend on CONFIG_FSDEV_9P which itself
depends on CONFIG_VIRTFS.

Remove the invalid CONFIG_9PFS and use CONFIG_FSDEV_9P instead, to
fix the './configure --without-default-devices --enable-xen' build:

  /usr/bin/ld: libcommon.fa.p/hw_xen_xen-legacy-backend.c.o: in function `xen_be_register_common':
  hw/xen/xen-legacy-backend.c:754: undefined reference to `xen_9pfs_ops'
  /usr/bin/ld: libcommon.fa.p/fsdev_qemu-fsdev.c.o:(.data.rel+0x8): undefined reference to `local_ops'
  /usr/bin/ld: libcommon.fa.p/fsdev_qemu-fsdev.c.o:(.data.rel+0x20): undefined reference to `synth_ops'
  /usr/bin/ld: libcommon.fa.p/fsdev_qemu-fsdev.c.o:(.data.rel+0x38): undefined reference to `proxy_ops'
  collect2: error: ld returned 1 exit status

Fixes: b2c00bce54 ("meson: convert hw/9pfs, cleanup")
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Greg Kurz <groug@kaod.org>
Tested-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Message-Id: <20201104115706.3101190-3-philmd@redhat.com>
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2020-11-05 15:21:11 +01:00
Xinhao Zhang 22e1367587 hw/9pfs : add space before the open parenthesis '('
Fix code style. Space required before the open parenthesis '('.

Signed-off-by: Xinhao Zhang <zhangxinhao1@huawei.com>
Signed-off-by: Kai Deng <dengkai1@huawei.com>
Reported-by: Euler Robot <euler.robot@huawei.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <20201030043515.1030223-3-zhangxinhao1@huawei.com>
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2020-11-05 15:14:03 +01:00
Xinhao Zhang 487729e9f6 hw/9pfs : open brace '{' following struct go on the same line
Fix code style. Open braces for struct should go on the same line.

Signed-off-by: Xinhao Zhang <zhangxinhao1@huawei.com>
Signed-off-by: Kai Deng <dengkai1@huawei.com>
Reported-by: Euler Robot <euler.robot@huawei.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <20201030043515.1030223-2-zhangxinhao1@huawei.com>
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2020-11-05 15:14:03 +01:00
Xinhao Zhang 01011733ea hw/9pfs : add spaces around operator
Fix code style. Operator needs spaces both sides.

Signed-off-by: Xinhao Zhang <zhangxinhao1@huawei.com>
Signed-off-by: Kai Deng <dengkai1@huawei.com>
Reported-by: Euler Robot <euler.robot@huawei.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <20201030043515.1030223-1-zhangxinhao1@huawei.com>
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2020-11-05 15:14:03 +01:00
Christian Schoenebeck b036d9ac69 9pfs: suppress performance warnings on qtest runs
Don't trigger any performance warning if we're just running test cases,
because tests intentionally run for edge cases.

So far performance warnings were suppressed for the 'synth' fs driver
backend only. This patch suppresses them for all 9p fs driver backends.

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <a2d2ff2163f8853ea782a7a1d4e6f2afd7c29ffe.1603106145.git.qemu_oss@crudebyte.com>
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2020-10-19 14:25:40 +02:00
Eduardo Habkost 8063396bf3 Use OBJECT_DECLARE_SIMPLE_TYPE when possible
This converts existing DECLARE_INSTANCE_CHECKER usage to
OBJECT_DECLARE_SIMPLE_TYPE when possible.

$ ./scripts/codeconverter/converter.py -i \
  --pattern=AddObjectDeclareSimpleType $(git grep -l '' -- '*.[ch]')

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Acked-by: Paul Durrant <paul@xen.org>
Message-Id: <20200916182519.415636-6-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2020-09-18 14:12:32 -04:00
Christian Schoenebeck c418f935ac 9pfs: disable msize warning for synth driver
Previous patch introduced a performance warning being logged on host
side if client connected with an 'msize' <= 8192. Disable this
performance warning for the synth driver to prevent that warning from
being printed whenever the 9pfs (qtest) test cases are running.

Introduce a new export flag V9FS_NO_PERF_WARN for that purpose, which
might also be used to disable such warnings from the CLI in future.

We could have also prevented the warning by simply raising P9_MAX_SIZE
in virtio-9p-test.c to any value larger than 8192, however in the
context of test cases it makes sense running for edge cases, which
includes the lowest 'msize' value supported by the server which is
4096, hence we want to preserve an msize of 4096 for the test client.

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <E1kEyDy-0006nN-5A@lizzy.crudebyte.com>
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2020-09-15 12:12:03 +02:00
Christian Schoenebeck 62777d825b 9pfs: log warning if msize <= 8192
It is essential to choose a reasonable high value for 'msize' to avoid
severely degraded file I/O performance. This parameter can only be
chosen on client/guest side, and a Linux client defaults to an 'msize'
of only 8192 if the user did not explicitly specify a value for 'msize',
which results in very poor file I/O performance.

Unfortunately many users are not aware that they should specify an
appropriate value for 'msize' to avoid severe performance issues, so
log a performance warning (with a QEMU wiki link explaining this issue
in detail) on host side in that case to make it more clear.

Currently a client cannot automatically pick a reasonable value for
'msize', because a good value for 'msize' depends on the file I/O
potential of the underlying storage on host side, i.e. a feature
invisible to the client, and even then a user would still need to trade
off between performance profit and additional RAM costs, i.e. with
growing 'msize' (RAM occupation), performance still increases, but
performance delta will shrink continuously.

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <e6fc84845c95816ad5baecb0abd6bfefdcf7ec9f.1599144062.git.qemu_oss@crudebyte.com>
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2020-09-15 12:12:03 +02:00
Eduardo Habkost 8110fa1d94 Use DECLARE_*CHECKER* macros
Generated using:

 $ ./scripts/codeconverter/converter.py -i \
   --pattern=TypeCheckMacro $(git grep -l '' -- '*.[ch]')

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20200831210740.126168-12-ehabkost@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20200831210740.126168-13-ehabkost@redhat.com>
Message-Id: <20200831210740.126168-14-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2020-09-09 09:27:09 -04:00
Eduardo Habkost db1015e92e Move QOM typedefs and add missing includes
Some typedefs and macros are defined after the type check macros.
This makes it difficult to automatically replace their
definitions with OBJECT_DECLARE_TYPE.

Patch generated using:

 $ ./scripts/codeconverter/converter.py -i \
   --pattern=QOMStructTypedefSplit $(git grep -l '' -- '*.[ch]')

which will split "typdef struct { ... } TypedefName"
declarations.

Followed by:

 $ ./scripts/codeconverter/converter.py -i --pattern=MoveSymbols \
    $(git grep -l '' -- '*.[ch]')

which will:
- move the typedefs and #defines above the type check macros
- add missing #include "qom/object.h" lines if necessary

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20200831210740.126168-9-ehabkost@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20200831210740.126168-10-ehabkost@redhat.com>
Message-Id: <20200831210740.126168-11-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2020-09-09 09:26:43 -04:00
Peter Maydell 30aa19446d 9pfs: Fix severe performance issue of Treaddir requests.
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Merge remote-tracking branch 'remotes/cschoenebeck/tags/pull-9p-20200812' into staging

9pfs: Fix severe performance issue of Treaddir requests.

# gpg: Signature made Wed 12 Aug 2020 11:06:21 BST
# gpg:                using RSA key 96D8D110CF7AF8084F88590134C2B58765A47395
# gpg:                issuer "qemu_oss@crudebyte.com"
# gpg: Good signature from "Christian Schoenebeck <qemu_oss@crudebyte.com>" [unknown]
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: ECAB 1A45 4014 1413 BA38  4926 30DB 47C3 A012 D5F4
#      Subkey fingerprint: 96D8 D110 CF7A F808 4F88  5901 34C2 B587 65A4 7395

* remotes/cschoenebeck/tags/pull-9p-20200812:
  9pfs: clarify latency of v9fs_co_run_in_worker()
  9pfs: differentiate readdir lock between 9P2000.u vs. 9P2000.L
  9pfs: T_readdir latency optimization
  9pfs: add new function v9fs_co_readdir_many()
  9pfs: split out fs driver core of v9fs_co_readdir()
  9pfs: make v9fs_readdir_response_size() public
  tests/virtio-9p: added split readdir tests

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-08-24 16:39:53 +01:00
Marc-André Lureau b2c00bce54 meson: convert hw/9pfs, cleanup
hw/Makefile.objs is gone so there is more code that can be removed.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-08-21 06:30:33 -04:00
Paolo Bonzini 243af0225a trace: switch position of headers to what Meson requires
Meson doesn't enjoy the same flexibility we have with Make in choosing
the include path.  In particular the tracing headers are using
$(build_root)/$(<D).

In order to keep the include directives unchanged,
the simplest solution is to generate headers with patterns like
"trace/trace-audio.h" and place forwarding headers in the source tree
such that for example "audio/trace.h" includes "trace/trace-audio.h".

This patch is too ugly to be applied to the Makefiles now.  It's only
a way to separate the changes to the tracing header files from the
Meson rewrite of the tracing logic.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-08-21 06:18:24 -04:00
Christian Schoenebeck da9f2eda25 9pfs: clarify latency of v9fs_co_run_in_worker()
As we just fixed a severe performance issue with Treaddir request
handling, clarify this overall issue as a comment on
v9fs_co_run_in_worker() with the intention to hopefully prevent
such performance mistakes in future (and fixing other yet
outstanding ones).

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Message-Id: <4d34d332e1aaa8a2cf8dc0b5da4fd7727f2a86e8.1596012787.git.qemu_oss@crudebyte.com>
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2020-08-12 09:17:32 +02:00
Christian Schoenebeck d2c5cf7ca1 9pfs: differentiate readdir lock between 9P2000.u vs. 9P2000.L
Previous patch suggests that it might make sense to use a different mutex
type now while handling readdir requests, depending on the precise
protocol variant, as v9fs_do_readdir_with_stat() (used by 9P2000.u) uses
a CoMutex to avoid deadlocks that might happen with QemuMutex otherwise,
whereas do_readdir_many() (used by 9P2000.L) should better use a
QemuMutex, as the precise behaviour of a failed CoMutex lock on fs driver
side would not be clear.

And to avoid the wrong lock type being used, be now strict and error out
if a 9P2000.L client sends a Tread on a directory, and likeweise error out
if a 9P2000.u client sends a Treaddir request.

This patch is just intended as transitional measure, as currently 9P2000.u
vs. 9P2000.L implementations currently differ where the main logic of
fetching directory entries is located at (9P2000.u still being more top
half focused, while 9P2000.L already being bottom half focused in regards
to fetching directory entries that is).

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Message-Id: <9a2ddc347e533b0d801866afd9dfac853d2d4106.1596012787.git.qemu_oss@crudebyte.com>
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2020-08-12 09:17:32 +02:00
Christian Schoenebeck 0c4356ba7d 9pfs: T_readdir latency optimization
Make top half really top half and bottom half really bottom half:

Each T_readdir request handling is hopping between threads (main
I/O thread and background I/O driver threads) several times for
every individual directory entry, which sums up to huge latencies
for handling just a single T_readdir request.

Instead of doing that, collect now all required directory entries
(including all potentially required stat buffers for each entry) in
one rush on a background I/O thread from fs driver by calling the
previously added function v9fs_co_readdir_many() instead of
v9fs_co_readdir(), then assemble the entire resulting network
response message for the readdir request on main I/O thread. The
fs driver is still aborting the directory entry retrieval loop
(on the background I/O thread inside of v9fs_co_readdir_many())
as soon as it would exceed the client's requested maximum R_readdir
response size. So this will not introduce a performance penalty on
another end.

Also: No longer seek initial directory position in v9fs_readdir(),
as this is now handled (more consistently) by
v9fs_co_readdir_many() instead.

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Message-Id: <c7c3d1cf4e86611538cef44897842819d9359d7a.1596012787.git.qemu_oss@crudebyte.com>
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2020-08-12 09:17:32 +02:00
Christian Schoenebeck 2149675b19 9pfs: add new function v9fs_co_readdir_many()
The newly added function v9fs_co_readdir_many() retrieves multiple
directory entries with a single fs driver request. It is intended to
replace uses of v9fs_co_readdir(), the latter only retrieves a
single directory entry per fs driver request instead.

The reason for this planned replacement is that for every fs driver
request the coroutine is dispatched from main I/O thread to a
background I/O thread and eventually dispatched back to main I/O
thread. Hopping between threads adds latency. So if a 9pfs Treaddir
request reads a large amount of directory entries, this currently
sums up to huge latencies of several hundred ms or even more. So
using v9fs_co_readdir_many() instead of v9fs_co_readdir() will
provide significant performance improvements.

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Message-Id: <73dc827a12ef577ae7e644dcf34a5c0e443ab42f.1596012787.git.qemu_oss@crudebyte.com>
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2020-08-12 09:17:32 +02:00
Christian Schoenebeck dd8151f4fe 9pfs: split out fs driver core of v9fs_co_readdir()
The implementation of v9fs_co_readdir() has two parts: the outer
part is executed by main I/O thread, whereas the inner part is
executed by fs driver on a background I/O thread.

Move the inner part to its own new, private function do_readdir(),
so it can be shared by another upcoming new function.

This is just a preparatory patch for the subsequent patch, with the
purpose to avoid the next patch to clutter the overall diff.

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <a426ee06e77584fa2d8253ce5d8bea519eb3ffd4.1596012787.git.qemu_oss@crudebyte.com>
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2020-08-12 09:17:32 +02:00
Christian Schoenebeck 29c9d2ca80 9pfs: make v9fs_readdir_response_size() public
Rename function v9fs_readdir_data_size() -> v9fs_readdir_response_size()
and make it callable from other units. So far this function is only
used by 9p.c, however subsequent patches require the function to be
callable from another 9pfs unit. And as we're at it; also make it clear
for what this function is used for.

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <3668ebc7d5b929a0e4f1357457060d96f50f76f4.1596012787.git.qemu_oss@crudebyte.com>
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2020-08-12 09:17:32 +02:00
Vladimir Sementsov-Ogievskiy 92c451222c virtio-9p: Use ERRP_GUARD()
If we want to check error after errp-function call, we need to
introduce local_err and then propagate it to errp. Instead, use
the ERRP_GUARD() macro, benefits are:
1. No need of explicit error_propagate call
2. No need of explicit local_err variable: use errp directly
3. ERRP_GUARD() leaves errp as is if it's not NULL or
   &error_fatal, this means that we don't break error_abort
   (we'll abort on error_set, not on error_propagate)

If we want to add some info to errp (by error_prepend() or
error_append_hint()), we must use the ERRP_GUARD() macro.
Otherwise, this info will not be added when errp == &error_fatal
(the program will exit prior to the error_append_hint() or
error_prepend() call).  Fix such a case in
v9fs_device_realize_common().

This commit is generated by command

    sed -n '/^virtio-9p$/,/^$/{s/^F: //p}' MAINTAINERS | \
    xargs git ls-files | grep '\.[hc]$' | \
    xargs spatch \
        --sp-file scripts/coccinelle/errp-guard.cocci \
        --macro-file scripts/cocci-macro-file.h \
        --in-place --no-show-diff --max-width 80

Reported-by: Kevin Wolf <kwolf@redhat.com>
Reported-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Acked-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
[Commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200707165037.1026246-7-armbru@redhat.com>
[ERRP_AUTO_PROPAGATE() renamed to ERRP_GUARD(), and
auto-propagated-errp.cocci to errp-guard.cocci.  Commit message
tweaked again.]
2020-07-10 15:18:09 +02:00
Markus Armbruster 9261ef5e32 Clean up some calls to ignore Error objects the right way
Receiving the error in a local variable only to free it is less clear
(and also less efficient) than passing NULL.  Clean up.

Cc: Daniel P. Berrange <berrange@redhat.com>
Cc: Jerome Forissier <jerome@forissier.org>
CC: Greg Kurz <groug@kaod.org>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <20200630090351.1247703-4-armbru@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
2020-07-02 06:25:28 +02:00
Stefano Stabellini 84af75577c xen/9pfs: increase max ring order to 9
The max order allowed by the protocol is 9. Increase the max order
supported by QEMU to 9 to increase performance.

Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com>
Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Message-Id: <20200521192627.15259-3-sstabellini@kernel.org>
Signed-off-by: Greg Kurz <groug@kaod.org>
2020-05-25 11:45:40 +02:00
Stefano Stabellini a4c4d46272 xen/9pfs: yield when there isn't enough room on the ring
Instead of truncating replies, which is problematic, wait until the
client reads more data and frees bytes on the reply ring.

Do that by calling qemu_coroutine_yield(). The corresponding
qemu_coroutine_enter_if_inactive() is called from xen_9pfs_bh upon
receiving the next notification from the client.

We need to be careful to avoid races in case xen_9pfs_bh and the
coroutine are both active at the same time. In xen_9pfs_bh, wait until
either the critical section is over (ring->co == NULL) or until the
coroutine becomes inactive (qemu_coroutine_yield() was called) before
continuing. Then, simply wake up the coroutine if it is inactive.

Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com>
Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Message-Id: <20200521192627.15259-2-sstabellini@kernel.org>
Signed-off-by: Greg Kurz <groug@kaod.org>
2020-05-25 11:45:39 +02:00
Stefano Stabellini cf45183b71 Revert "9p: init_in_iov_from_pdu can truncate the size"
This reverts commit 16724a1730.
It causes https://bugs.launchpad.net/bugs/1877688.

Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com>
Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Message-Id: <20200521192627.15259-1-sstabellini@kernel.org>
Signed-off-by: Greg Kurz <groug@kaod.org>
2020-05-25 11:45:38 +02:00
Greg Kurz ed463454ef 9p: Lock directory streams with a CoMutex
Locking was introduced in QEMU 2.7 to address the deprecation of
readdir_r(3) in glibc 2.24. It turns out that the frontend code is
the worst place to handle a critical section with a pthread mutex:
the code runs in a coroutine on behalf of the QEMU mainloop and then
yields control, waiting for the fsdev backend to process the request
in a worker thread. If the client resends another readdir request for
the same fid before the previous one finally unlocked the mutex, we're
deadlocked.

This never bit us because the linux client serializes readdir requests
for the same fid, but it is quite easy to demonstrate with a custom
client.

A good solution could be to narrow the critical section in the worker
thread code and to return a copy of the dirent to the frontend, but
this causes quite some changes in both 9p.c and codir.c. So, instead
of that, in order for people to easily backport the fix to older QEMU
versions, let's simply use a CoMutex since all the users for this
sit in coroutines.

Fixes: 7cde47d4a8 ("9p: add locking to V9fsDir")
Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Message-Id: <158981894794.109297.3530035833368944254.stgit@bahia.lan>
Signed-off-by: Greg Kurz <groug@kaod.org>
2020-05-25 10:38:03 +02:00
Dan Robertson 03556ea920 9pfs: include linux/limits.h for XATTR_SIZE_MAX
linux/limits.h should be included for the XATTR_SIZE_MAX definition used
by v9fs_xattrcreate.

Fixes: 3b79ef2cf4 ("9pfs: limit xattr size in xattrcreate")
Signed-off-by: Dan Robertson <dan@dlrobertson.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Message-Id: <20200515203015.7090-2-dan@dlrobertson.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
2020-05-25 10:38:03 +02:00
Markus Armbruster b69c3c21a5 qdev: Unrealize must not fail
Devices may have component devices and buses.

Device realization may fail.  Realization is recursive: a device's
realize() method realizes its components, and device_set_realized()
realizes its buses (which should in turn realize the devices on that
bus, except bus_set_realized() doesn't implement that, yet).

When realization of a component or bus fails, we need to roll back:
unrealize everything we realized so far.  If any of these unrealizes
failed, the device would be left in an inconsistent state.  Must not
happen.

device_set_realized() lets it happen: it ignores errors in the roll
back code starting at label child_realize_fail.

Since realization is recursive, unrealization must be recursive, too.
But how could a partly failed unrealize be rolled back?  We'd have to
re-realize, which can fail.  This design is fundamentally broken.

device_set_realized() does not roll back at all.  Instead, it keeps
unrealizing, ignoring further errors.

It can screw up even for a device with no buses: if the lone
dc->unrealize() fails, it still unregisters vmstate, and calls
listeners' unrealize() callback.

bus_set_realized() does not roll back either.  Instead, it stops
unrealizing.

Fortunately, no unrealize method can fail, as we'll see below.

To fix the design error, drop parameter @errp from all the unrealize
methods.

Any unrealize method that uses @errp now needs an update.  This leads
us to unrealize() methods that can fail.  Merely passing it to another
unrealize method cannot cause failure, though.  Here are the ones that
do other things with @errp:

* virtio_serial_device_unrealize()

  Fails when qbus_set_hotplug_handler() fails, but still does all the
  other work.  On failure, the device would stay realized with its
  resources completely gone.  Oops.  Can't happen, because
  qbus_set_hotplug_handler() can't actually fail here.  Pass
  &error_abort to qbus_set_hotplug_handler() instead.

* hw/ppc/spapr_drc.c's unrealize()

  Fails when object_property_del() fails, but all the other work is
  already done.  On failure, the device would stay realized with its
  vmstate registration gone.  Oops.  Can't happen, because
  object_property_del() can't actually fail here.  Pass &error_abort
  to object_property_del() instead.

* spapr_phb_unrealize()

  Fails and bails out when remove_drcs() fails, but other work is
  already done.  On failure, the device would stay realized with some
  of its resources gone.  Oops.  remove_drcs() fails only when
  chassis_from_bus()'s object_property_get_uint() fails, and it can't
  here.  Pass &error_abort to remove_drcs() instead.

Therefore, no unrealize method can fail before this patch.

device_set_realized()'s recursive unrealization via bus uses
object_property_set_bool().  Can't drop @errp there, so pass
&error_abort.

We similarly unrealize with object_property_set_bool() elsewhere,
always ignoring errors.  Pass &error_abort instead.

Several unrealize methods no longer handle errors from other unrealize
methods: virtio_9p_device_unrealize(),
virtio_input_device_unrealize(), scsi_qdev_unrealize(), ...
Much of the deleted error handling looks wrong anyway.

One unrealize methods no longer ignore such errors:
usb_ehci_pci_exit().

Several realize methods no longer ignore errors when rolling back:
v9fs_device_realize_common(), pci_qdev_unrealize(),
spapr_phb_realize(), usb_qdev_realize(), vfio_ccw_realize(),
virtio_device_realize().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200505152926.18877-17-armbru@redhat.com>
2020-05-15 07:08:14 +02:00
Christian Schoenebeck 9bbb7e0fe0 xen-9pfs: Fix log messages of reply errors
If delivery of some 9pfs response fails for some reason, log the
error message by mentioning the 9P protocol reply type, not by
client's request type. The latter could be misleading that the
error occurred already when handling the request input.

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Message-Id: <ad0e5a9b6abde52502aa40b30661d29aebe1590a.1589132512.git.qemu_oss@crudebyte.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
2020-05-14 08:06:43 +02:00
Omar Sandoval a5804fcf7b 9pfs: local: ignore O_NOATIME if we don't have permissions
QEMU's local 9pfs server passes through O_NOATIME from the client. If
the QEMU process doesn't have permissions to use O_NOATIME (namely, it
does not own the file nor have the CAP_FOWNER capability), the open will
fail. This causes issues when from the client's point of view, it
believes it has permissions to use O_NOATIME (e.g., a process running as
root in the virtual machine). Additionally, overlayfs on Linux opens
files on the lower layer using O_NOATIME, so in this case a 9pfs mount
can't be used as a lower layer for overlayfs (cf.
dabfe19719/vmtest/onoatimehack.c
and https://github.com/NixOS/nixpkgs/issues/54509).

Luckily, O_NOATIME is effectively a hint, and is often ignored by, e.g.,
network filesystems. open(2) notes that O_NOATIME "may not be effective
on all filesystems. One example is NFS, where the server maintains the
access time." This means that we can honor it when possible but fall
back to ignoring it.

Acked-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Message-Id: <e9bee604e8df528584693a4ec474ded6295ce8ad.1587149256.git.osandov@fb.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
2020-05-14 08:06:43 +02:00
Greg Kurz 659f195328 9p/proxy: Fix export_flags
The common fsdev options are set by qemu_fsdev_add() before it calls
the backend specific option parsing code. In the case of "proxy" this
means "writeout" or "readonly" were simply ignored. This has been
broken from the beginning.

Reported-by: Stéphane Graber <stgraber@ubuntu.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Message-Id: <158349633705.1237488.8895481990204796135.stgit@bahia.lan>
2020-03-10 16:12:49 +01:00
Christian Schoenebeck af46a3b233 hw/9pfs/9p-synth: added directory for readdir test
This will provide the following virtual files by the 9pfs
synth driver:

  - /ReadDirDir/ReadDirFile99
  - /ReadDirDir/ReadDirFile98
  ...
  - /ReadDirDir/ReadDirFile1
  - /ReadDirDir/ReadDirFile0

This virtual directory and its virtual 100 files will be
used by the upcoming 9pfs readdir tests.

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <5408c28c8de25dd575b745cef63bf785305ccef2.1579567020.git.qemu_oss@crudebyte.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
2020-02-08 09:29:04 +01:00
Christian Schoenebeck d36a5c2270 9pfs: validate count sent by client with T_readdir
A good 9p client sends T_readdir with "count" parameter that's sufficiently
smaller than client's initially negotiated msize (maximum message size).
We perform a check for that though to avoid the server to be interrupted
with a "Failed to encode VirtFS reply type 41" transport error message by
bad clients. This count value constraint uses msize - 11, because 11 is the
header size of R_readdir.

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <3990d3891e8ae2074709b56449e96ab4b4b93b7d.1579567020.git.qemu_oss@crudebyte.com>
[groug: added comment ]
Signed-off-by: Greg Kurz <groug@kaod.org>
2020-02-08 09:28:54 +01:00
Christian Schoenebeck e16453a31a 9pfs: require msize >= 4096
A client establishes a session by sending a Tversion request along with a
'msize' parameter which client uses to suggest server a maximum message
size ever to be used for communication (for both requests and replies)
between client and server during that session. If client suggests a 'msize'
smaller than 4096 then deny session by server immediately with an error
response (Rlerror for "9P2000.L" clients or Rerror for "9P2000.u" clients)
instead of replying with Rversion.

So far any msize submitted by client with Tversion was simply accepted by
server without any check. Introduction of some minimum msize makes sense,
because e.g. a msize < 7 would not allow any subsequent 9p operation at
all, because 7 is the size of the header section common by all 9p message
types.

A substantial higher value of 4096 was chosen though to prevent potential
issues with some message types. E.g. Rreadlink may yield up to a size of
PATH_MAX which is usually 4096, and like almost all 9p message types,
Rreadlink is not allowed to be truncated by the 9p protocol. This chosen
size also prevents a similar issue with Rreaddir responses (provided client
always sends adequate 'count' parameter with Treaddir), because even though
directory entries retrieval may be split up over several T/Rreaddir
messages; a Rreaddir response must not truncate individual directory entries
though. So msize should be large enough to return at least one directory
entry with the longest possible file name supported by host. Most file
systems support a max. file name length of 255. Largest known file name
lenght limit would be currently ReiserFS with max. 4032 bytes, which is
also covered by this min. msize value because 4032 + 35 < 4096.

Furthermore 4096 is already the minimum msize of the Linux kernel's 9pfs
client.

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <8ceecb7fb9fdbeabbe55c04339349a36929fb8e3.1579567019.git.qemu_oss@crudebyte.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
2020-02-08 09:28:43 +01:00
Peter Maydell 760df0d121 * Register qdev properties as class properties (Marc-André)
* Cleanups (Philippe)
 * virtio-scsi fix (Pan Nengyuan)
 * Tweak Skylake-v3 model id (Kashyap)
 * x86 UCODE_REV support and nested live migration fix (myself)
 * Advisory mode for pvpanic (Zhenwei)
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Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into staging

* Register qdev properties as class properties (Marc-André)
* Cleanups (Philippe)
* virtio-scsi fix (Pan Nengyuan)
* Tweak Skylake-v3 model id (Kashyap)
* x86 UCODE_REV support and nested live migration fix (myself)
* Advisory mode for pvpanic (Zhenwei)

# gpg: Signature made Fri 24 Jan 2020 20:16:23 GMT
# gpg:                using RSA key BFFBD25F78C7AE83
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>" [full]
# gpg:                 aka "Paolo Bonzini <pbonzini@redhat.com>" [full]
# Primary key fingerprint: 46F5 9FBD 57D6 12E7 BFD4  E2F7 7E15 100C CD36 69B1
#      Subkey fingerprint: F133 3857 4B66 2389 866C  7682 BFFB D25F 78C7 AE83

* remotes/bonzini/tags/for-upstream: (58 commits)
  build-sys: clean up flags included in the linker command line
  target/i386: Add the 'model-id' for Skylake -v3 CPU models
  qdev: use object_property_help()
  qapi/qmp: add ObjectPropertyInfo.default-value
  qom: introduce object_property_help()
  qom: simplify qmp_device_list_properties()
  vl: print default value in object help
  qdev: register properties as class properties
  qdev: move instance properties to class properties
  qdev: rename DeviceClass.props
  qdev: set properties with device_class_set_props()
  object: return self in object_ref()
  object: release all props
  object: add object_class_property_add_link()
  object: express const link with link property
  object: add direct link flag
  object: rename link "child" to "target"
  object: check strong flag with &
  object: do not free class properties
  object: add object_property_set_default
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-01-27 09:44:04 +00:00
Marc-André Lureau 4f67d30b5e qdev: set properties with device_class_set_props()
The following patch will need to handle properties registration during
class_init time. Let's use a device_class_set_props() setter.

spatch --macro-file scripts/cocci-macro-file.h  --sp-file
./scripts/coccinelle/qdev-set-props.cocci --keep-comments --in-place
--dir .

@@
typedef DeviceClass;
DeviceClass *d;
expression val;
@@
- d->props = val
+ device_class_set_props(d, val)

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20200110153039.1379601-20-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-24 20:59:15 +01:00
Pan Nengyuan ad30a9e904 virtio-9p-device: convert to new virtio_delete_queue
Use virtio_delete_queue to make it more clear.

Signed-off-by: Pan Nengyuan <pannengyuan@huawei.com>
Message-Id: <20200117060927.51996-3-pannengyuan@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2020-01-22 00:23:07 -05:00
Pan Nengyuan 9580d60e66 virtio-9p-device: fix memleak in virtio_9p_device_unrealize
v->vq forgot to cleanup in virtio_9p_device_unrealize, the memory leak
stack is as follow:

Direct leak of 14336 byte(s) in 2 object(s) allocated from:
  #0 0x7f819ae43970 (/lib64/libasan.so.5+0xef970)  ??:?
  #1 0x7f819872f49d (/lib64/libglib-2.0.so.0+0x5249d)  ??:?
  #2 0x55a3a58da624 (./x86_64-softmmu/qemu-system-x86_64+0x2c14624)  /mnt/sdb/qemu/hw/virtio/virtio.c:2327
  #3 0x55a3a571bac7 (./x86_64-softmmu/qemu-system-x86_64+0x2a55ac7)  /mnt/sdb/qemu/hw/9pfs/virtio-9p-device.c:209
  #4 0x55a3a58e7bc6 (./x86_64-softmmu/qemu-system-x86_64+0x2c21bc6)  /mnt/sdb/qemu/hw/virtio/virtio.c:3504
  #5 0x55a3a5ebfb37 (./x86_64-softmmu/qemu-system-x86_64+0x31f9b37)  /mnt/sdb/qemu/hw/core/qdev.c:876

Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Pan Nengyuan <pannengyuan@huawei.com>
Message-Id: <20200117060927.51996-2-pannengyuan@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Acked-by: Greg Kurz <groug@kaod.org>
2020-01-22 00:23:07 -05:00
Daniel Henrique Barboza b858e80a02 9pfs/9p.c: remove unneeded labels
'out' label in v9fs_xattr_write() and 'out_nofid' label in
v9fs_complete_rename() can be replaced by appropriate return
calls.

CC: Greg Kurz <groug@kaod.org>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Acked-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Greg Kurz <groug@kaod.org>
2020-01-20 15:11:39 +01:00
Greg Kurz 16724a1730 9p: init_in_iov_from_pdu can truncate the size
init_in_iov_from_pdu might not be able to allocate the full buffer size
requested, which comes from the client and could be larger than the
transport has available at the time of the request. Specifically, this
can happen with read operations, with the client requesting a read up to
the max allowed, which might be more than the transport has available at
the time.

Today the implementation of init_in_iov_from_pdu throws an error, both
Xen and Virtio.

Instead, change the V9fsTransport interface so that the size becomes a
pointer and can be limited by the implementation of
init_in_iov_from_pdu.

Change both the Xen and Virtio implementations to set the size to the
size of the buffer they managed to allocate, instead of throwing an
error. However, if the allocated buffer size is less than P9_IOHDRSZ
(the size of the header) still throw an error as the case is unhandable.

Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com>
CC: groug@kaod.org
CC: anthony.perard@citrix.com
CC: roman@zededa.com
CC: qemu_oss@crudebyte.com
[groug: fix 32-bit build]
Signed-off-by: Greg Kurz <groug@kaod.org>
2020-01-20 15:11:39 +01:00
Daniel Henrique Barboza 846cf408a4 9p: local: always return -1 on error in local_unlinkat_common
local_unlinkat_common() is supposed to always return -1 on error.
This is being done by jumps to the 'err_out' label, which is
a 'return ret' call, and 'ret' is initialized with -1.

Unfortunately there is a condition in which the function will
return 0 on error: in a case where flags == AT_REMOVEDIR, 'ret'
will be 0 when reaching

map_dirfd = openat_dir(...)

And, if map_dirfd == -1 and errno != ENOENT, the existing 'err_out'
jump will execute 'return ret', when ret is still set to zero
at that point.

This patch fixes it by changing all 'err_out' labels by
'return -1' calls, ensuring that the function will always
return -1 on error conditions. 'ret' can be left unintialized
since it's now being used just to store the result of 'unlinkat'
calls.

CC: Greg Kurz <groug@kaod.org>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
[groug: changed prefix in title to be "9p: local:"]
Signed-off-by: Greg Kurz <groug@kaod.org>
2020-01-20 15:11:39 +01:00
Jiajun Chen 841b8d099c 9pfs: local: Fix possible memory leak in local_link()
There is a possible memory leak while local_link return -1 without free
odirpath and oname.

Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Jaijun Chen <chenjiajun8@huawei.com>
Signed-off-by: Xiang Zheng <zhengxiang9@huawei.com>
Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
2020-01-20 15:11:39 +01:00
Vladimir Sementsov-Ogievskiy 4c5ec47e63 9pfs: make Error **errp const where it is appropriate
Mostly, Error ** is for returning error from the function, so the
callee sets it. However error_append_security_model_hint and
error_append_socket_sockfd_hint get already filled errp
parameter. They don't change the pointer itself, only change the
internal state of referenced Error object. So we can make it Error
*const * errp, to stress the behavior. It will also help coccinelle
script (in future) to distinguish such cases from common errp usage.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Acked-by: Greg Kurz <groug@kaod.org>
Message-Id: <20191205174635.18758-9-vsementsov@virtuozzo.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Commit message replaced]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2019-12-18 08:43:19 +01:00
Dan Schatzberg 68d654daee 9pfs: Fix divide by zero bug
Some filesystems may return 0s in statfs (trivially, a FUSE filesystem
can do so). QEMU should handle this gracefully and just behave the
same as if statfs failed.

Signed-off-by: Dan Schatzberg <dschatzberg@fb.com>
Acked-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
2019-11-23 15:51:48 +01:00
Christian Schoenebeck 6b6aa8285d 9p: Use variable length suffixes for inode remapping
Use variable length suffixes for inode remapping instead of the fixed
16 bit size prefixes before. With this change the inode numbers on guest
will typically be much smaller (e.g. around >2^1 .. >2^7 instead of >2^48
with the previous fixed size inode remapping.

Additionally this solution is more efficient, since inode numbers in
practice can take almost their entire 64 bit range on guest as well, so
there is less likely a need for generating and tracking additional suffixes,
which might also be beneficial for nested virtualization where each level of
virtualization would shift up the inode bits and increase the chance of
expensive remapping actions.

The "Exponential Golomb" algorithm is used as basis for generating the
variable length suffixes. The algorithm has a parameter k which controls the
distribution of bits on increasing indeces (minimum bits at low index vs.
maximum bits at high index). With k=0 the generated suffixes look like:

Index Dec/Bin -> Generated Suffix Bin
1 [1] -> [1] (1 bits)
2 [10] -> [010] (3 bits)
3 [11] -> [110] (3 bits)
4 [100] -> [00100] (5 bits)
5 [101] -> [10100] (5 bits)
6 [110] -> [01100] (5 bits)
7 [111] -> [11100] (5 bits)
8 [1000] -> [0001000] (7 bits)
9 [1001] -> [1001000] (7 bits)
10 [1010] -> [0101000] (7 bits)
11 [1011] -> [1101000] (7 bits)
12 [1100] -> [0011000] (7 bits)
...
65533 [1111111111111101] ->  [1011111111111111000000000000000] (31 bits)
65534 [1111111111111110] ->  [0111111111111111000000000000000] (31 bits)
65535 [1111111111111111] ->  [1111111111111111000000000000000] (31 bits)
Hence minBits=1 maxBits=31

And with k=5 they would look like:

Index Dec/Bin -> Generated Suffix Bin
1 [1] -> [000001] (6 bits)
2 [10] -> [100001] (6 bits)
3 [11] -> [010001] (6 bits)
4 [100] -> [110001] (6 bits)
5 [101] -> [001001] (6 bits)
6 [110] -> [101001] (6 bits)
7 [111] -> [011001] (6 bits)
8 [1000] -> [111001] (6 bits)
9 [1001] -> [000101] (6 bits)
10 [1010] -> [100101] (6 bits)
11 [1011] -> [010101] (6 bits)
12 [1100] -> [110101] (6 bits)
...
65533 [1111111111111101] -> [0011100000000000100000000000] (28 bits)
65534 [1111111111111110] -> [1011100000000000100000000000] (28 bits)
65535 [1111111111111111] -> [0111100000000000100000000000] (28 bits)
Hence minBits=6 maxBits=28

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
2019-10-10 11:36:23 +02:00
Antonios Motakis f3fe4a2d92 9p: stat_to_qid: implement slow path
stat_to_qid attempts via qid_path_prefixmap to map unique files (which are
identified by 64 bit inode nr and 32 bit device id) to a 64 QID path value.
However this implementation makes some assumptions about inode number
generation on the host.

If qid_path_prefixmap fails, we still have 48 bits available in the QID
path to fall back to a less memory efficient full mapping.

Signed-off-by: Antonios Motakis <antonios.motakis@huawei.com>
[CS: - Rebased to https://github.com/gkurz/qemu/commits/9p-next
       (SHA1 7fc4c49e91).
     - Updated hash calls to new xxhash API.
     - Removed unnecessary parantheses in qpf_lookup_func().
     - Removed unnecessary g_malloc0() result checks.
     - Log error message when running out of prefixes in
       qid_path_fullmap().
     - Log warning message about potential degraded performance in
       qid_path_prefixmap().
     - Wrapped qpf_table initialization to dedicated qpf_table_init()
       function.
     - Fixed typo in comment. ]
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
2019-10-10 11:36:14 +02:00
Antonios Motakis 1a6ed33cc5 9p: Added virtfs option 'multidevs=remap|forbid|warn'
'warn' (default): Only log an error message (once) on host if more than one
device is shared by same export, except of that just ignore this config
error though. This is the default behaviour for not breaking existing
installations implying that they really know what they are doing.

'forbid': Like 'warn', but except of just logging an error this
also denies access of guest to additional devices.

'remap': Allows to share more than one device per export by remapping
inodes from host to guest appropriately. To support multiple devices on the
9p share, and avoid qid path collisions we take the device id as input to
generate a unique QID path. The lowest 48 bits of the path will be set
equal to the file inode, and the top bits will be uniquely assigned based
on the top 16 bits of the inode and the device id.

Signed-off-by: Antonios Motakis <antonios.motakis@huawei.com>
[CS: - Rebased to https://github.com/gkurz/qemu/commits/9p-next
       (SHA1 7fc4c49e91).
     - Added virtfs option 'multidevs', original patch simply did the inode
       remapping without being asked.
     - Updated hash calls to new xxhash API.
     - Updated docs for new option 'multidevs'.
     - Fixed v9fs_do_readdir() not having remapped inodes.
     - Log error message when running out of prefixes in
       qid_path_prefixmap().
     - Fixed definition of QPATH_INO_MASK.
     - Wrapped qpp_table initialization to dedicated qpp_table_init()
       function.
     - Dropped unnecessary parantheses in qpp_lookup_func().
     - Dropped unnecessary g_malloc0() result checks. ]
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
[groug: - Moved "multidevs" parsing to the local backend.
        - Added hint to invalid multidevs option error.
	- Turn "remap" into "x-remap". ]
Signed-off-by: Greg Kurz <groug@kaod.org>
2019-10-10 11:36:05 +02:00
Antonios Motakis 3b5ee9e86b 9p: Treat multiple devices on one export as an error
The QID path should uniquely identify a file. However, the
inode of a file is currently used as the QID path, which
on its own only uniquely identifies files within a device.
Here we track the device hosting the 9pfs share, in order
to prevent security issues with QID path collisions from
other devices.

We only print a warning for now but a subsequent patch will
allow users to have finer control over the desired behaviour.
Failing the I/O will be one the proposed behaviour, so we
also change stat_to_qid() to return an error here in order to
keep other patches simpler.

Signed-off-by: Antonios Motakis <antonios.motakis@huawei.com>
[CS: - Assign dev_id to export root's device already in
       v9fs_device_realize_common(), not postponed in
       stat_to_qid().
     - error_report_once() if more than one device was
       shared by export.
     - Return -ENODEV instead of -ENOSYS in stat_to_qid().
     - Fixed typo in log comment. ]
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
[groug, changed to warning, updated message and changelog]
Signed-off-by: Greg Kurz <groug@kaod.org>
2019-10-10 11:36:05 +02:00
Greg Kurz ea52cdd443 fsdev: Add return value to fsdev_throttle_parse_opts()
It is more convenient to use the return value of the function to notify
errors, rather than to be tied up setting up the &local_err boilerplate.

Signed-off-by: Greg Kurz <groug@kaod.org>
2019-10-10 11:36:05 +02:00
Greg Kurz c0da0cb761 9p: Simplify error path of v9fs_device_realize_common()
Make v9fs_device_unrealize_common() idempotent and use it for rollback,
in order to reduce code duplication.

Signed-off-by: Greg Kurz <groug@kaod.org>
2019-10-10 11:36:04 +02:00
Antonios Motakis 8703283352 9p: unsigned type for type, version, path
There is no need for signedness on these QID fields for 9p.

Signed-off-by: Antonios Motakis <antonios.motakis@huawei.com>
[CS: - Also make QID type unsigned.
     - Adjust donttouch_stat() to new types.
     - Adjust trace-events to new types. ]
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
2019-10-10 11:36:04 +02:00