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2023-05-169pfs/xen: Fix segfault on shutdownJason Andryuk1-13/+22
xen_9pfs_free can't use gnttabdev since it is already closed and NULL-ed out when free is called. Do the teardown in _disconnect(). This matches the setup done in _connect(). trace-events are also added for the XenDevOps functions. Signed-off-by: Jason Andryuk <jandryuk@gmail.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Message-Id: <20230502143722.15613-1-jandryuk@gmail.com> [C.S.: - Remove redundant return in xen_9pfs_free(). - Add comment to trace-events. ] Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2023-04-28hw: replace most qemu_bh_new calls with qemu_bh_new_guardedAlexander Bulekov1-1/+4
This protects devices from bh->mmio reentrancy issues. Thanks: Thomas Huth <thuth@redhat.com> for diagnosing OS X test failure. Signed-off-by: Alexander Bulekov <alxndr@bu.edu> Reviewed-by: Darren Kenny <darren.kenny@oracle.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Paul Durrant <paul@xen.org> Reviewed-by: Thomas Huth <thuth@redhat.com> Message-Id: <20230427211013.2994127-5-alxndr@bu.edu> Signed-off-by: Thomas Huth <thuth@redhat.com>
2023-03-07hw/xen: Rename xen_common.h to xen_native.hDavid Woodhouse1-0/+1
This header is now only for native Xen code, not PV backends that may be used in Xen emulation. Since the toolstack libraries may depend on the specific version of Xen headers that they pull in (and will set the __XEN_TOOLS__ macro to enable internal definitions that they depend on), the rule is that xen_native.h (and thus the toolstack library headers) must be included *before* any of the headers in include/hw/xen/interface. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-07hw/xen: Pass grant ref to gnttab unmap operationDavid Woodhouse1-3/+4
The previous commit introduced redirectable gnttab operations fairly much like-for-like, with the exception of the extra arguments to the ->open() call which were always NULL/0 anyway. This *changes* the arguments to the ->unmap() operation to include the original ref# that was mapped. Under real Xen it isn't necessary; all we need to do from QEMU is munmap(), then the kernel will release the grant, and Xen does the tracking/refcounting for the guest. When we have emulated grant tables though, we need to do all that for ourselves. So let's have the back ends keep track of what they mapped and pass it in to the ->unmap() method for us. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-07hw/xen: Add evtchn operations to allow redirection to internal emulationDavid Woodhouse1-12/+12
The existing implementation calling into the real libxenevtchn moves to a new file hw/xen/xen-operations.c, and is called via a function table which in a subsequent commit will also be able to invoke the emulated event channel support. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Paul Durrant <paul@xen.org>
2021-07-059pfs: add link to 9p developer docsChristian Schoenebeck1-0/+5
To lower the entry level for new developers, add a link to the 9p developer docs (i.e. qemu wiki) to MAINTAINERS and to the beginning of 9p source files, that is to: https://wiki.qemu.org/Documentation/9p Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Acked-by: Greg Kurz <groug@kaod.org> Message-Id: <E1leeDf-0008GZ-9q@lizzy.crudebyte.com>
2020-05-25xen/9pfs: increase max ring order to 9Stefano Stabellini1-1/+1
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>
2020-05-25xen/9pfs: yield when there isn't enough room on the ringStefano Stabellini1-6/+25
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>
2020-05-25Revert "9p: init_in_iov_from_pdu can truncate the size"Stefano Stabellini1-9/+6
This reverts commit 16724a173049ac29c7b5ade741da93a0f46edff7. 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>
2020-05-14xen-9pfs: Fix log messages of reply errorsChristian Schoenebeck1-4/+5
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>
2020-01-209p: init_in_iov_from_pdu can truncate the sizeGreg Kurz1-5/+8
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>
2019-08-16Include qemu/main-loop.h lessMarkus Armbruster1-0/+1
In my "build everything" tree, changing qemu/main-loop.h triggers a recompile of some 5600 out of 6600 objects (not counting tests and objects that don't depend on qemu/osdep.h). It includes block/aio.h, which in turn includes qemu/event_notifier.h, qemu/notify.h, qemu/processor.h, qemu/qsp.h, qemu/queue.h, qemu/thread-posix.h, qemu/thread.h, qemu/timer.h, and a few more. Include qemu/main-loop.h only where it's needed. Touching it now recompiles only some 1700 objects. For block/aio.h and qemu/event_notifier.h, these numbers drop from 5600 to 2800. For the others, they shrink only slightly. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20190812052359.30071-21-armbru@redhat.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2019-08-16Include hw/hw.h exactly where neededMarkus Armbruster1-1/+0
In my "build everything" tree, changing hw/hw.h triggers a recompile of some 2600 out of 6600 objects (not counting tests and objects that don't depend on qemu/osdep.h). The previous commits have left only the declaration of hw_error() in hw/hw.h. This permits dropping most of its inclusions. Touching it now recompiles less than 200 objects. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Message-Id: <20190812052359.30071-19-armbru@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2019-01-14xen: re-name XenDevice to XenLegacyDevice...Paul Durrant1-8/+8
...and xen_backend.h to xen-legacy-backend.h Rather than attempting to convert the existing backend infrastructure to be QOM compliant (which would be hard to do in an incremental fashion), subsequent patches will introduce a completely new framework for Xen PV backends. Hence it is necessary to re-name parts of existing code to avoid name clashes. The re-named 'legacy' infrastructure will be removed once all backends have been ported to the new framework. This patch is purely cosmetic. No functional change. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Acked-by: Anthony Perard <anthony.perard@citrix.com> Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
2018-12-12xen/9pfs: use g_new(T, n) instead of g_malloc(sizeof(T) * n)Greg Kurz1-3/+3
Because it is a recommended coding practice (see HACKING). Signed-off-by: Greg Kurz <groug@kaod.org> Acked-by: Anthony PERARD <anthony.perard@citrix.com>
2018-10-19fsdev: Clean up error reporting in qemu_fsdev_add()Markus Armbruster1-1/+6
Calling error_report() from within a function that takes an Error ** argument is suspicious. qemu_fsdev_add() does that, and its caller fsdev_init_func() then fails without setting an error. Its caller main(), via qemu_opts_foreach(), is fine with it, but clean it up anyway. Cc: Greg Kurz <groug@kaod.org> Signed-off-by: Markus Armbruster <armbru@redhat.com> Acked-by: Greg Kurz <groug@kaod.org> Message-Id: <20181017082702.5581-32-armbru@redhat.com>
2018-05-22xen: remove other open-coded use of libxengnttabPaul Durrant1-17/+15
Now that helpers are available in xen_backend, use them throughout all Xen PV backends. 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>
2018-02-09Move include qemu/option.h from qemu-common.h to actual usersMarkus Armbruster1-0/+1
qemu-common.h includes qemu/option.h, but most places that include the former don't actually need the latter. Drop the include, and add it to the places that actually need it. While there, drop superfluous includes of both headers, and separate #include from file comment with a blank line. This cleanup makes the number of objects depending on qemu/option.h drop from 4545 (out of 4743) to 284 in my "build everything" tree. Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20180201111846.21846-20-armbru@redhat.com> [Semantic conflict with commit bdd6a90a9e in block/nvme.c resolved]
2018-02-019pfs: drop v9fs_register_transport()Greg Kurz1-2/+1
No good reasons to do this outside of v9fs_device_realize_common(). Signed-off-by: Greg Kurz <groug@kaod.org> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
2018-01-089pfs: fix some type definitionsGreg Kurz1-1/+1
To comply with the QEMU coding style. Signed-off-by: Greg Kurz <groug@kaod.org>
2017-06-29xen-9pfs: disconnect if buffers are misconfiguredStefano Stabellini1-21/+64
Implement xen_9pfs_disconnect by unbinding the event channels. On xen_9pfs_free, call disconnect if any event channels haven't been disconnected. If the frontend misconfigured the buffers set the backend to "Closing" and disconnect it. Misconfigurations include requesting a read of more bytes than available on the ring buffer, or claiming to be writing more data than available on the ring buffer. Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Signed-off-by: Greg Kurz <groug@kaod.org>
2017-06-29virtio-9p: break device if buffers are misconfiguredGreg Kurz1-1/+2
The 9P protocol is transport agnostic: if the guest misconfigured the buffers, the best we can do is to set the broken flag on the device. Signed-off-by: Greg Kurz <groug@kaod.org>
2017-05-25virtio-9p/xen-9p: move 9p specific bits to core 9p codeGreg Kurz1-5/+1
These bits aren't related to the transport so let's move them to the core code. Signed-off-by: Greg Kurz <groug@kaod.org> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
2017-05-16xen: call qemu_set_cloexec instead of fcntlStefano Stabellini1-1/+1
Use the common utility function, which contains checks on return values and first calls F_GETFD as recommended by POSIX.1-2001, instead of manually calling fcntl. CID: 1374831 Signed-off-by: Stefano Stabellini <sstabellini@kernel.org> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Greg Kurz <groug@kaod.org> CC: anthony.perard@citrix.com CC: groug@kaod.org CC: aneesh.kumar@linux.vnet.ibm.com CC: Eric Blake <eblake@redhat.com>
2017-05-16xen/9pfs: fix two resource leaks on error paths, discovered by CoverityStefano Stabellini1-0/+2
CID: 1374836 Signed-off-by: Stefano Stabellini <sstabellini@kernel.org> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Greg Kurz <groug@kaod.org> CC: anthony.perard@citrix.com CC: groug@kaod.org CC: aneesh.kumar@linux.vnet.ibm.com
2017-04-25xen/9pfs: send responses back to the frontendStefano Stabellini1-0/+19
Once a request is completed, xen_9pfs_push_and_notify gets called. In xen_9pfs_push_and_notify, update the indexes (data has already been copied to the sg by the common code) and send a notification to the frontend. Schedule the bottom-half to check if we already have any other requests pending. Signed-off-by: Stefano Stabellini <stefano@aporeto.com> CC: anthony.perard@citrix.com CC: jgross@suse.com CC: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> CC: Greg Kurz <groug@kaod.org>
2017-04-25xen/9pfs: implement in/out_iov_from_pdu and vmarshal/vunmarshalStefano Stabellini1-2/+97
Implement xen_9pfs_init_in/out_iov_from_pdu and xen_9pfs_pdu_vmarshal/vunmarshall by creating new sg pointing to the data on the ring. This is safe as we only handle one request per ring at any given time. Signed-off-by: Stefano Stabellini <stefano@aporeto.com> CC: anthony.perard@citrix.com CC: jgross@suse.com CC: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> CC: Greg Kurz <groug@kaod.org>
2017-04-25xen/9pfs: receive requests from the frontendStefano Stabellini1-0/+50
Upon receiving an event channel notification from the frontend, schedule the bottom half. From the bottom half, read one request from the ring, create a pdu and call pdu_submit to handle it. For now, only handle one request per ring at a time. Signed-off-by: Stefano Stabellini <stefano@aporeto.com> CC: anthony.perard@citrix.com CC: jgross@suse.com CC: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> CC: Greg Kurz <groug@kaod.org>
2017-04-25xen/9pfs: connect to the frontendStefano Stabellini1-1/+181
Write the limits of the backend to xenstore. Connect to the frontend. Upon connection, allocate the rings according to the protocol specification. Initialize a QEMUBH to schedule work upon receiving an event channel notification from the frontend. Signed-off-by: Stefano Stabellini <stefano@aporeto.com> CC: anthony.perard@citrix.com CC: jgross@suse.com CC: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> CC: Greg Kurz <groug@kaod.org>
2017-04-25xen/9pfs: introduce Xen 9pfs backendStefano Stabellini1-0/+96
Introduce the Xen 9pfs backend: add struct XenDevOps to register as a Xen backend and add struct V9fsTransport to register as v9fs transport. All functions are empty stubs for now. Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Reviewed-by: Greg Kurz <groug@kaod.org> CC: anthony.perard@citrix.com CC: jgross@suse.com CC: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> CC: Greg Kurz <groug@kaod.org>