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2021-02-03xen: Fix XenStore initialisation for XS_LOCALDavid Woodhouse
commit 5f46400f7a6a4fad635d5a79e2aa5a04a30ffea1 upstream. In commit 3499ba8198ca ("xen: Fix event channel callback via INTX/GSI") I reworked the triggering of xenbus_probe(). I tried to simplify things by taking out the workqueue based startup triggered from wake_waiting(); the somewhat poorly named xenbus IRQ handler. I missed the fact that in the XS_LOCAL case (Dom0 starting its own xenstored or xenstore-stubdom, which happens after the kernel is booted completely), that IRQ-based trigger is still actually needed. So... put it back, except more cleanly. By just spawning a xenbus_probe thread which waits on xb_waitq and runs the probe the first time it gets woken, just as the workqueue-based hack did. This is actually a nicer approach for *all* the back ends with different interrupt methods, and we can switch them all over to that without the complex conditions for when to trigger it. But not in -rc6. This is the minimal fix for the regression, although it's a step in the right direction instead of doing a partial revert and actually putting the workqueue back. It's also simpler than the workqueue. Fixes: 3499ba8198ca ("xen: Fix event channel callback via INTX/GSI") Reported-by: Juergen Gross <jgross@suse.com> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/4c9af052a6e0f6485d1de43f2c38b1461996db99.camel@infradead.org Signed-off-by: Juergen Gross <jgross@suse.com> Cc: Salvatore Bonaccorso <carnil@debian.org> Cc: Jason Andryuk <jandryuk@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-27xen: Fix event channel callback via INTX/GSIDavid Woodhouse
[ Upstream commit 3499ba8198cad47b731792e5e56b9ec2a78a83a2 ] For a while, event channel notification via the PCI platform device has been broken, because we attempt to communicate with xenstore before we even have notifications working, with the xs_reset_watches() call in xs_init(). We tend to get away with this on Xen versions below 4.0 because we avoid calling xs_reset_watches() anyway, because xenstore might not cope with reading a non-existent key. And newer Xen *does* have the vector callback support, so we rarely fall back to INTX/GSI delivery. To fix it, clean up a bit of the mess of xs_init() and xenbus_probe() startup. Call xs_init() directly from xenbus_init() only in the !XS_HVM case, deferring it to be called from xenbus_probe() in the XS_HVM case instead. Then fix up the invocation of xenbus_probe() to happen either from its device_initcall if the callback is available early enough, or when the callback is finally set up. This means that the hack of calling xenbus_probe() from a workqueue after the first interrupt, or directly from the PCI platform device setup, is no longer needed. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Link: https://lore.kernel.org/r/20210113132606.422794-2-dwmw2@infradead.org Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-23xen/privcmd: allow fetching resource sizesRoger Pau Monne
commit ef3a575baf53571dc405ee4028e26f50856898e7 upstream. Allow issuing an IOCTL_PRIVCMD_MMAP_RESOURCE ioctl with num = 0 and addr = 0 in order to fetch the size of a specific resource. Add a shortcut to the default map resource path, since fetching the size requires no address to be passed in, and thus no VMA to setup. This is missing from the initial implementation, and causes issues when mapping resources that don't have fixed or known sizes. Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Reviewed-by: Juergen Gross <jgross@suse.com> Tested-by: Andrew Cooper <andrew.cooper3@citrix.com> Cc: stable@vger.kernel.org # >= 4.18 Link: https://lore.kernel.org/r/20210112115358.23346-1-roger.pau@citrix.com Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-30xenbus/xenbus_backend: Disallow pending watch messagesSeongJae Park
commit 9996bd494794a2fe393e97e7a982388c6249aa76 upstream. 'xenbus_backend' watches 'state' of devices, which is writable by guests. Hence, if guests intensively updates it, dom0 will have lots of pending events that exhausting memory of dom0. In other words, guests can trigger dom0 memory pressure. This is known as XSA-349. However, the watch callback of it, 'frontend_changed()', reads only 'state', so doesn't need to have the pending events. To avoid the problem, this commit disallows pending watch messages for 'xenbus_backend' using the 'will_handle()' watch callback. This is part of XSA-349 Cc: stable@vger.kernel.org Signed-off-by: SeongJae Park <sjpark@amazon.de> Reported-by: Michael Kurth <mku@amazon.de> Reported-by: Pawel Wieczorkiewicz <wipawel@amazon.de> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-30xen/xenbus: Count pending messages for each watchSeongJae Park
commit 3dc86ca6b4c8cfcba9da7996189d1b5a358a94fc upstream. This commit adds a counter of pending messages for each watch in the struct. It is used to skip unnecessary pending messages lookup in 'unregister_xenbus_watch()'. It could also be used in 'will_handle' callback. This is part of XSA-349 Cc: stable@vger.kernel.org Signed-off-by: SeongJae Park <sjpark@amazon.de> Reported-by: Michael Kurth <mku@amazon.de> Reported-by: Pawel Wieczorkiewicz <wipawel@amazon.de> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-30xen/xenbus/xen_bus_type: Support will_handle watch callbackSeongJae Park
commit be987200fbaceaef340872841d4f7af2c5ee8dc3 upstream. This commit adds support of the 'will_handle' watch callback for 'xen_bus_type' users. This is part of XSA-349 Cc: stable@vger.kernel.org Signed-off-by: SeongJae Park <sjpark@amazon.de> Reported-by: Michael Kurth <mku@amazon.de> Reported-by: Pawel Wieczorkiewicz <wipawel@amazon.de> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-30xen/xenbus: Add 'will_handle' callback support in xenbus_watch_path()SeongJae Park
commit 2e85d32b1c865bec703ce0c962221a5e955c52c2 upstream. Some code does not directly make 'xenbus_watch' object and call 'register_xenbus_watch()' but use 'xenbus_watch_path()' instead. This commit adds support of 'will_handle' callback in the 'xenbus_watch_path()' and it's wrapper, 'xenbus_watch_pathfmt()'. This is part of XSA-349 Cc: stable@vger.kernel.org Signed-off-by: SeongJae Park <sjpark@amazon.de> Reported-by: Michael Kurth <mku@amazon.de> Reported-by: Pawel Wieczorkiewicz <wipawel@amazon.de> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-30xen/xenbus: Allow watches discard events before queueingSeongJae Park
commit fed1755b118147721f2c87b37b9d66e62c39b668 upstream. If handling logics of watch events are slower than the events enqueue logic and the events can be created from the guests, the guests could trigger memory pressure by intensively inducing the events, because it will create a huge number of pending events that exhausting the memory. Fortunately, some watch events could be ignored, depending on its handler callback. For example, if the callback has interest in only one single path, the watch wouldn't want multiple pending events. Or, some watches could ignore events to same path. To let such watches to volutarily help avoiding the memory pressure situation, this commit introduces new watch callback, 'will_handle'. If it is not NULL, it will be called for each new event just before enqueuing it. Then, if the callback returns false, the event will be discarded. No watch is using the callback for now, though. This is part of XSA-349 Cc: stable@vger.kernel.org Signed-off-by: SeongJae Park <sjpark@amazon.de> Reported-by: Michael Kurth <mku@amazon.de> Reported-by: Pawel Wieczorkiewicz <wipawel@amazon.de> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-05xen/events: block rogue events for some timeJuergen Gross
commit 5f7f77400ab5b357b5fdb7122c3442239672186c upstream. In order to avoid high dom0 load due to rogue guests sending events at high frequency, block those events in case there was no action needed in dom0 to handle the events. This is done by adding a per-event counter, which set to zero in case an EOI without the XEN_EOI_FLAG_SPURIOUS is received from a backend driver, and incremented when this flag has been set. In case the counter is 2 or higher delay the EOI by 1 << (cnt - 2) jiffies, but not more than 1 second. In order not to waste memory shorten the per-event refcnt to two bytes (it should normally never exceed a value of 2). Add an overflow check to evtchn_get() to make sure the 2 bytes really won't overflow. This is part of XSA-332. Cc: stable@vger.kernel.org Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Reviewed-by: Wei Liu <wl@xen.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-05xen/events: defer eoi in case of excessive number of eventsJuergen Gross
commit e99502f76271d6bc4e374fe368c50c67a1fd3070 upstream. In case rogue guests are sending events at high frequency it might happen that xen_evtchn_do_upcall() won't stop processing events in dom0. As this is done in irq handling a crash might be the result. In order to avoid that, delay further inter-domain events after some time in xen_evtchn_do_upcall() by forcing eoi processing into a worker on the same cpu, thus inhibiting new events coming in. The time after which eoi processing is to be delayed is configurable via a new module parameter "event_loop_timeout" which specifies the maximum event loop time in jiffies (default: 2, the value was chosen after some tests showing that a value of 2 was the lowest with an only slight drop of dom0 network throughput while multiple guests performed an event storm). How long eoi processing will be delayed can be specified via another parameter "event_eoi_delay" (again in jiffies, default 10, again the value was chosen after testing with different delay values). This is part of XSA-332. Cc: stable@vger.kernel.org Reported-by: Julien Grall <julien@xen.org> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Reviewed-by: Wei Liu <wl@xen.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-05xen/events: use a common cpu hotplug hook for event channelsJuergen Gross
commit 7beb290caa2adb0a399e735a1e175db9aae0523a upstream. Today only fifo event channels have a cpu hotplug callback. In order to prepare for more percpu (de)init work move that callback into events_base.c and add percpu_init() and percpu_deinit() hooks to struct evtchn_ops. This is part of XSA-332. Cc: stable@vger.kernel.org Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Wei Liu <wl@xen.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-05xen/events: switch user event channels to lateeoi modelJuergen Gross
commit c44b849cee8c3ac587da3b0980e01f77500d158c upstream. Instead of disabling the irq when an event is received and enabling it again when handled by the user process use the lateeoi model. This is part of XSA-332. Cc: stable@vger.kernel.org Reported-by: Julien Grall <julien@xen.org> Signed-off-by: Juergen Gross <jgross@suse.com> Tested-by: Stefano Stabellini <sstabellini@kernel.org> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Reviewed-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Wei Liu <wl@xen.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-05xen/pciback: use lateeoi irq bindingJuergen Gross
commit c2711441bc961b37bba0615dd7135857d189035f upstream. In order to reduce the chance for the system becoming unresponsive due to event storms triggered by a misbehaving pcifront use the lateeoi irq binding for pciback and unmask the event channel only just before leaving the event handling function. Restructure the handling to support that scheme. Basically an event can come in for two reasons: either a normal request for a pciback action, which is handled in a worker, or in case the guest has finished an AER request which was requested by pciback. When an AER request is issued to the guest and a normal pciback action is currently active issue an EOI early in order to be able to receive another event when the AER request has been finished by the guest. Let the worker processing the normal requests run until no further request is pending, instead of starting a new worker ion that case. Issue the EOI only just before leaving the worker. This scheme allows to drop calling the generic function xen_pcibk_test_and_schedule_op() after processing of any request as the handling of both request types is now separated more cleanly. This is part of XSA-332. Cc: stable@vger.kernel.org Reported-by: Julien Grall <julien@xen.org> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Wei Liu <wl@xen.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-05xen/pvcallsback: use lateeoi irq bindingJuergen Gross
commit c8d647a326f06a39a8e5f0f1af946eacfa1835f8 upstream. In order to reduce the chance for the system becoming unresponsive due to event storms triggered by a misbehaving pvcallsfront use the lateeoi irq binding for pvcallsback and unmask the event channel only after handling all write requests, which are the ones coming in via an irq. This requires modifying the logic a little bit to not require an event for each write request, but to keep the ioworker running until no further data is found on the ring page to be processed. This is part of XSA-332. Cc: stable@vger.kernel.org Reported-by: Julien Grall <julien@xen.org> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Reviewed-by: Wei Liu <wl@xen.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-05xen/scsiback: use lateeoi irq bindingJuergen Gross
commit 86991b6e7ea6c613b7692f65106076943449b6b7 upstream. In order to reduce the chance for the system becoming unresponsive due to event storms triggered by a misbehaving scsifront use the lateeoi irq binding for scsiback and unmask the event channel only just before leaving the event handling function. In case of a ring protocol error don't issue an EOI in order to avoid the possibility to use that for producing an event storm. This at once will result in no further call of scsiback_irq_fn(), so the ring_error struct member can be dropped and scsiback_do_cmd_fn() can signal the protocol error via a negative return value. This is part of XSA-332. Cc: stable@vger.kernel.org Reported-by: Julien Grall <julien@xen.org> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Wei Liu <wl@xen.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-05xen/events: add a new "late EOI" evtchn frameworkJuergen Gross
commit 54c9de89895e0a36047fcc4ae754ea5b8655fb9d upstream. In order to avoid tight event channel related IRQ loops add a new framework of "late EOI" handling: the IRQ the event channel is bound to will be masked until the event has been handled and the related driver is capable to handle another event. The driver is responsible for unmasking the event channel via the new function xen_irq_lateeoi(). This is similar to binding an event channel to a threaded IRQ, but without having to structure the driver accordingly. In order to support a future special handling in case a rogue guest is sending lots of unsolicited events, add a flag to xen_irq_lateeoi() which can be set by the caller to indicate the event was a spurious one. This is part of XSA-332. Cc: stable@vger.kernel.org Reported-by: Julien Grall <julien@xen.org> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Reviewed-by: Wei Liu <wl@xen.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-05xen/events: fix race in evtchn_fifo_unmask()Juergen Gross
commit f01337197419b7e8a492e83089552b77d3b5fb90 upstream. Unmasking a fifo event channel can result in unmasking it twice, once directly in the kernel and once via a hypercall in case the event was pending. Fix that by doing the local unmask only if the event is not pending. This is part of XSA-332. Cc: stable@vger.kernel.org Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-05xen/events: add a proper barrier to 2-level uevent unmaskingJuergen Gross
commit 4d3fe31bd993ef504350989786858aefdb877daa upstream. A follow-up patch will require certain write to happen before an event channel is unmasked. While the memory barrier is not strictly necessary for all the callers, the main one will need it. In order to avoid an extra memory barrier when using fifo event channels, mandate evtchn_unmask() to provide write ordering. The 2-level event handling unmask operation is missing an appropriate barrier, so add it. Fifo event channels are fine in this regard due to using sync_cmpxchg(). This is part of XSA-332. Cc: stable@vger.kernel.org Suggested-by: Julien Grall <julien@xen.org> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Julien Grall <jgrall@amazon.com> Reviewed-by: Wei Liu <wl@xen.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-05xen/events: avoid removing an event channel while handling itJuergen Gross
commit 073d0552ead5bfc7a3a9c01de590e924f11b5dd2 upstream. Today it can happen that an event channel is being removed from the system while the event handling loop is active. This can lead to a race resulting in crashes or WARN() splats when trying to access the irq_info structure related to the event channel. Fix this problem by using a rwlock taken as reader in the event handling loop and as writer when deallocating the irq_info structure. As the observed problem was a NULL dereference in evtchn_from_irq() make this function more robust against races by testing the irq_info pointer to be not NULL before dereferencing it. And finally make all accesses to evtchn_to_irq[row][col] atomic ones in order to avoid seeing partial updates of an array element in irq handling. Note that irq handling can be entered only for event channels which have been valid before, so any not populated row isn't a problem in this regard, as rows are only ever added and never removed. This is XSA-331. Cc: stable@vger.kernel.org Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> Reported-by: Jinoh Kang <luke1337@theori.io> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Reviewed-by: Wei Liu <wl@xen.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-01xen/gntdev.c: Mark pages as dirtySouptick Joarder
commit 779055842da5b2e508f3ccf9a8153cb1f704f566 upstream. There seems to be a bug in the original code when gntdev_get_page() is called with writeable=true then the page needs to be marked dirty before being put. To address this, a bool writeable is added in gnt_dev_copy_batch, set it in gntdev_grant_copy_seg() (and drop `writeable` argument to gntdev_get_page()) and then, based on batch->writeable, use set_page_dirty_lock(). Fixes: a4cdb556cae0 (xen/gntdev: add ioctl for grant copy) Suggested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/1599375114-32360-1-git-send-email-jrdr.linux@gmail.com Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-17xen/events: don't use chip_data for legacy IRQsJuergen Gross
commit 0891fb39ba67bd7ae023ea0d367297ffff010781 upstream. Since commit c330fb1ddc0a ("XEN uses irqdesc::irq_data_common::handler_data to store a per interrupt XEN data pointer which contains XEN specific information.") Xen is using the chip_data pointer for storing IRQ specific data. When running as a HVM domain this can result in problems for legacy IRQs, as those might use chip_data for their own purposes. Use a local array for this purpose in case of legacy IRQs, avoiding the double use. Cc: stable@vger.kernel.org Fixes: c330fb1ddc0a ("XEN uses irqdesc::irq_data_common::handler_data to store a per interrupt XEN data pointer which contains XEN specific information.") Signed-off-by: Juergen Gross <jgross@suse.com> Tested-by: Stefan Bader <stefan.bader@canonical.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Link: https://lore.kernel.org/r/20200930091614.13660-1-jgross@suse.com Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-09xen/xenbus: Fix granting of vmalloc'd memorySimon Leiner
[ Upstream commit d742db70033c745e410523e00522ee0cfe2aa416 ] On some architectures (like ARM), virt_to_gfn cannot be used for vmalloc'd memory because of its reliance on virt_to_phys. This patch introduces a check for vmalloc'd addresses and obtains the PFN using vmalloc_to_pfn in that case. Signed-off-by: Simon Leiner <simon@leiner.me> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Link: https://lore.kernel.org/r/20200825093153.35500-1-simon@leiner.me Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-03XEN uses irqdesc::irq_data_common::handler_data to store a per interrupt XEN ↵Thomas Gleixner
data pointer which contains XEN specific information. commit c330fb1ddc0a922f044989492b7fcca77ee1db46 upstream. handler data is meant for interrupt handlers and not for storing irq chip specific information as some devices require handler data to store internal per interrupt information, e.g. pinctrl/GPIO chained interrupt handlers. This obviously creates a conflict of interests and crashes the machine because the XEN pointer is overwritten by the driver pointer. As the XEN data is not handler specific it should be stored in irqdesc::irq_data::chip_data instead. A simple sed s/irq_[sg]et_handler_data/irq_[sg]et_chip_data/ cures that. Cc: stable@vger.kernel.org Reported-by: Roman Shaposhnik <roman@zededa.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Roman Shaposhnik <roman@zededa.com> Reviewed-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/87lfi2yckt.fsf@nanos.tec.linutronix.de Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-26xen: don't reschedule in preemption off sectionsJuergen Gross
For support of long running hypercalls xen_maybe_preempt_hcall() is calling cond_resched() in case a hypercall marked as preemptible has been interrupted. Normally this is no problem, as only hypercalls done via some ioctl()s are marked to be preemptible. In rare cases when during such a preemptible hypercall an interrupt occurs and any softirq action is started from irq_exit(), a further hypercall issued by the softirq handler will be regarded to be preemptible, too. This might lead to rescheduling in spite of the softirq handler potentially having set preempt_disable(), leading to splats like: BUG: sleeping function called from invalid context at drivers/xen/preempt.c:37 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 20775, name: xl INFO: lockdep is turned off. CPU: 1 PID: 20775 Comm: xl Tainted: G D W 5.4.46-1_prgmr_debug.el7.x86_64 #1 Call Trace: <IRQ> dump_stack+0x8f/0xd0 ___might_sleep.cold.76+0xb2/0x103 xen_maybe_preempt_hcall+0x48/0x70 xen_do_hypervisor_callback+0x37/0x40 RIP: e030:xen_hypercall_xen_version+0xa/0x20 Code: ... RSP: e02b:ffffc900400dcc30 EFLAGS: 00000246 RAX: 000000000004000d RBX: 0000000000000200 RCX: ffffffff8100122a RDX: ffff88812e788000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffffff83ee3ad0 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000246 R12: ffff8881824aa0b0 R13: 0000000865496000 R14: 0000000865496000 R15: ffff88815d040000 ? xen_hypercall_xen_version+0xa/0x20 ? xen_force_evtchn_callback+0x9/0x10 ? check_events+0x12/0x20 ? xen_restore_fl_direct+0x1f/0x20 ? _raw_spin_unlock_irqrestore+0x53/0x60 ? debug_dma_sync_single_for_cpu+0x91/0xc0 ? _raw_spin_unlock_irqrestore+0x53/0x60 ? xen_swiotlb_sync_single_for_cpu+0x3d/0x140 ? mlx4_en_process_rx_cq+0x6b6/0x1110 [mlx4_en] ? mlx4_en_poll_rx_cq+0x64/0x100 [mlx4_en] ? net_rx_action+0x151/0x4a0 ? __do_softirq+0xed/0x55b ? irq_exit+0xea/0x100 ? xen_evtchn_do_upcall+0x2c/0x40 ? xen_do_hypervisor_callback+0x29/0x40 </IRQ> ? xen_hypercall_domctl+0xa/0x20 ? xen_hypercall_domctl+0x8/0x20 ? privcmd_ioctl+0x221/0x990 [xen_privcmd] ? do_vfs_ioctl+0xa5/0x6f0 ? ksys_ioctl+0x60/0x90 ? trace_hardirqs_off_thunk+0x1a/0x20 ? __x64_sys_ioctl+0x16/0x20 ? do_syscall_64+0x62/0x250 ? entry_SYSCALL_64_after_hwframe+0x49/0xbe Fix that by testing preempt_count() before calling cond_resched(). In kernel 5.8 this can't happen any more due to the entry code rework (more than 100 patches, so not a candidate for backporting). The issue was introduced in kernel 4.3, so this patch should go into all stable kernels in [4.3 ... 5.7]. Reported-by: Sarah Newman <srn@prgmr.com> Fixes: 0fa2f5cb2b0ecd8 ("sched/preempt, xen: Use need_resched() instead of should_resched()") Cc: Sarah Newman <srn@prgmr.com> Cc: stable@vger.kernel.org Signed-off-by: Juergen Gross <jgross@suse.com> Tested-by: Chris Brannon <cmb@prgmr.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-26swiotlb-xen: use vmalloc_to_page on vmalloc virt addressesBoris Ostrovsky
[ Upstream commit 8b1e868f66076490189a36d984fcce286cdd6295 ] xen_alloc_coherent_pages might return pages for which virt_to_phys and virt_to_page don't work, e.g. ioremap'ed pages. So in xen_swiotlb_free_coherent we can't assume that virt_to_page works. Instead add a is_vmalloc_addr check and use vmalloc_to_page on vmalloc virt addresses. This patch fixes the following crash at boot on RPi4 (the underlying issue is not RPi4 specific): https://marc.info/?l=xen-devel&m=158862573216800 Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Tested-by: Corey Minyard <cminyard@mvista.com> Tested-by: Roman Shaposhnik <roman@zededa.com> Link: https://lore.kernel.org/r/20200710223427.6897-1-sstabellini@kernel.org Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-19xen/gntdev: Fix dmabuf import with non-zero sgt offsetOleksandr Andrushchenko
commit 5fa4e6f1c2d8c9a4e47e1931b42893172d388f2b upstream. It is possible that the scatter-gather table during dmabuf import has non-zero offset of the data, but user-space doesn't expect that. Fix this by failing the import, so user-space doesn't access wrong data. Fixes: bf8dc55b1358 ("xen/gntdev: Implement dma-buf import functionality") Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Acked-by: Juergen Gross <jgross@suse.com> Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20200813062113.11030-2-andr2000@gmail.com Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-19xen/balloon: make the balloon wait interruptibleRoger Pau Monne
commit 88a479ff6ef8af7f07e11593d58befc644244ff7 upstream. So it can be killed, or else processes can get hung indefinitely waiting for balloon pages. Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Reviewed-by: Juergen Gross <jgross@suse.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200727091342.52325-3-roger.pau@citrix.com Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-19xen/balloon: fix accounting in alloc_xenballooned_pages error pathRoger Pau Monne
commit 1951fa33ec259abdf3497bfee7b63e7ddbb1a394 upstream. target_unpopulated is incremented with nr_pages at the start of the function, but the call to free_xenballooned_pages will only subtract pgno number of pages, and thus the rest need to be subtracted before returning or else accounting will be skewed. Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Reviewed-by: Juergen Gross <jgross@suse.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200727091342.52325-2-roger.pau@citrix.com Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-17xen/pvcalls-back: test for errors when calling backend_connect()Juergen Gross
commit c8d70a29d6bbc956013f3401f92a4431a9385a3c upstream. backend_connect() can fail, so switch the device to connected only if no error occurred. Fixes: 0a9c75c2c7258f2 ("xen/pvcalls: xenbus state handling") Cc: stable@vger.kernel.org Signed-off-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/20200511074231.19794-1-jgross@suse.com Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-02xen/xenbus: ensure xenbus_map_ring_valloc() returns proper grant statusJuergen Gross
[ Upstream commit 6b51fd3f65a22e3d1471b18a1d56247e246edd46 ] xenbus_map_ring_valloc() maps a ring page and returns the status of the used grant (0 meaning success). There are Xen hypervisors which might return the value 1 for the status of a failed grant mapping due to a bug. Some callers of xenbus_map_ring_valloc() test for errors by testing the returned status to be less than zero, resulting in no error detected and crashing later due to a not available ring page. Set the return value of xenbus_map_ring_valloc() to GNTST_general_error in case the grant status reported by Xen is greater than zero. This is part of XSA-316. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Wei Liu <wl@xen.org> Link: https://lore.kernel.org/r/20200326080358.1018-1-jgross@suse.com Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-03-25xenbus: req->err should be updated before req->stateDongli Zhang
[ Upstream commit 8130b9d5b5abf26f9927b487c15319a187775f34 ] This patch adds the barrier to guarantee that req->err is always updated before req->state. Otherwise, read_reply() would not return ERR_PTR(req->err) but req->body, when process_writes()->xb_write() is failed. Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com> Link: https://lore.kernel.org/r/20200303221423.21962-2-dongli.zhang@oracle.com Reviewed-by: Julien Grall <jgrall@amazon.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-03-25xenbus: req->body should be updated before req->stateDongli Zhang
[ Upstream commit 1b6a51e86cce38cf4d48ce9c242120283ae2f603 ] The req->body should be updated before req->state is updated and the order should be guaranteed by a barrier. Otherwise, read_reply() might return req->body = NULL. Below is sample callstack when the issue is reproduced on purpose by reordering the updates of req->body and req->state and adding delay in code between updates of req->state and req->body. [ 22.356105] general protection fault: 0000 [#1] SMP PTI [ 22.361185] CPU: 2 PID: 52 Comm: xenwatch Not tainted 5.5.0xen+ #6 [ 22.366727] Hardware name: Xen HVM domU, BIOS ... [ 22.372245] RIP: 0010:_parse_integer_fixup_radix+0x6/0x60 ... ... [ 22.392163] RSP: 0018:ffffb2d64023fdf0 EFLAGS: 00010246 [ 22.395933] RAX: 0000000000000000 RBX: 75746e7562755f6d RCX: 0000000000000000 [ 22.400871] RDX: 0000000000000000 RSI: ffffb2d64023fdfc RDI: 75746e7562755f6d [ 22.405874] RBP: 0000000000000000 R08: 00000000000001e8 R09: 0000000000cdcdcd [ 22.410945] R10: ffffb2d6402ffe00 R11: ffff9d95395eaeb0 R12: ffff9d9535935000 [ 22.417613] R13: ffff9d9526d4a000 R14: ffff9d9526f4f340 R15: ffff9d9537654000 [ 22.423726] FS: 0000000000000000(0000) GS:ffff9d953bc80000(0000) knlGS:0000000000000000 [ 22.429898] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 22.434342] CR2: 000000c4206a9000 CR3: 00000001ea3fc002 CR4: 00000000001606e0 [ 22.439645] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 22.444941] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 22.450342] Call Trace: [ 22.452509] simple_strtoull+0x27/0x70 [ 22.455572] xenbus_transaction_start+0x31/0x50 [ 22.459104] netback_changed+0x76c/0xcc1 [xen_netfront] [ 22.463279] ? find_watch+0x40/0x40 [ 22.466156] xenwatch_thread+0xb4/0x150 [ 22.469309] ? wait_woken+0x80/0x80 [ 22.472198] kthread+0x10e/0x130 [ 22.474925] ? kthread_park+0x80/0x80 [ 22.477946] ret_from_fork+0x35/0x40 [ 22.480968] Modules linked in: xen_kbdfront xen_fbfront(+) xen_netfront xen_blkfront [ 22.486783] ---[ end trace a9222030a747c3f7 ]--- [ 22.490424] RIP: 0010:_parse_integer_fixup_radix+0x6/0x60 The virt_rmb() is added in the 'true' path of test_reply(). The "while" is changed to "do while" so that test_reply() is used as a read memory barrier. Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com> Link: https://lore.kernel.org/r/20200303221423.21962-1-dongli.zhang@oracle.com Reviewed-by: Julien Grall <jgrall@amazon.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-28xen: Enable interrupts when calling _cond_resched()Thomas Gleixner
commit 8645e56a4ad6dcbf504872db7f14a2f67db88ef2 upstream. xen_maybe_preempt_hcall() is called from the exception entry point xen_do_hypervisor_callback with interrupts disabled. _cond_resched() evades the might_sleep() check in cond_resched() which would have caught that and schedule_debug() unfortunately lacks a check for irqs_disabled(). Enable interrupts around the call and use cond_resched() to catch future issues. Fixes: fdfd811ddde3 ("x86/xen: allow privcmd hypercalls to be preempted") Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/878skypjrh.fsf@nanos.tec.linutronix.de Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11xen/balloon: Support xend-based toolstack take twoJuergen Gross
commit eda4eabf86fd6806eaabc23fb90dd056fdac037b upstream. Commit 3aa6c19d2f38be ("xen/balloon: Support xend-based toolstack") tried to fix a regression with running on rather ancient Xen versions. Unfortunately the fix was based on the assumption that xend would just use another Xenstore node, but in reality only some downstream versions of xend are doing that. The upstream xend does not write that Xenstore node at all, so the problem must be fixed in another way. The easiest way to achieve that is to fall back to the behavior before commit 96edd61dcf4436 ("xen/balloon: don't online new memory initially") in case the static memory maximum can't be read. This is achieved by setting static_max to the current number of memory pages known by the system resulting in target_diff becoming zero. Fixes: 3aa6c19d2f38be ("xen/balloon: Support xend-based toolstack") Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: <stable@vger.kernel.org> # 4.13 Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-09xen/balloon: fix ballooned page accounting without hotplug enabledJuergen Gross
[ Upstream commit c673ec61ade89bf2f417960f986bc25671762efb ] When CONFIG_XEN_BALLOON_MEMORY_HOTPLUG is not defined reserve_additional_memory() will set balloon_stats.target_pages to a wrong value in case there are still some ballooned pages allocated via alloc_xenballooned_pages(). This will result in balloon_process() no longer be triggered when ballooned pages are freed in batches. Reported-by: Nicholas Tsirakis <niko.tsirakis@gmail.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-31xen/gntdev: Use select for DMA_SHARED_BUFFERJason Gunthorpe
[ Upstream commit fa6614d8ef13c63aac52ad7c07c5e69ce4aba3dd ] DMA_SHARED_BUFFER can not be enabled by the user (it represents a library set in the kernel). The kconfig convention is to use select for such symbols so they are turned on implicitly when the user enables a kconfig that needs them. Otherwise the XEN_GNTDEV_DMABUF kconfig is overly difficult to enable. Fixes: 932d6562179e ("xen/gntdev: Add initial support for dma-buf UAPI") Cc: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: xen-devel@lists.xenproject.org Cc: Juergen Gross <jgross@suse.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Reviewed-by: Juergen Gross <jgross@suse.com> Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-19Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netLinus Torvalds
Pull networking fixes from David Miller: "I was battling a cold after some recent trips, so quite a bit piled up meanwhile, sorry about that. Highlights: 1) Fix fd leak in various bpf selftests, from Brian Vazquez. 2) Fix crash in xsk when device doesn't support some methods, from Magnus Karlsson. 3) Fix various leaks and use-after-free in rxrpc, from David Howells. 4) Fix several SKB leaks due to confusion of who owns an SKB and who should release it in the llc code. From Eric Biggers. 5) Kill a bunc of KCSAN warnings in TCP, from Eric Dumazet. 6) Jumbo packets don't work after resume on r8169, as the BIOS resets the chip into non-jumbo mode during suspend. From Heiner Kallweit. 7) Corrupt L2 header during MPLS push, from Davide Caratti. 8) Prevent possible infinite loop in tc_ctl_action, from Eric Dumazet. 9) Get register bits right in bcmgenet driver, based upon chip version. From Florian Fainelli. 10) Fix mutex problems in microchip DSA driver, from Marek Vasut. 11) Cure race between route lookup and invalidation in ipv4, from Wei Wang. 12) Fix performance regression due to false sharing in 'net' structure, from Eric Dumazet" * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (145 commits) net: reorder 'struct net' fields to avoid false sharing net: dsa: fix switch tree list net: ethernet: dwmac-sun8i: show message only when switching to promisc net: aquantia: add an error handling in aq_nic_set_multicast_list net: netem: correct the parent's backlog when corrupted packet was dropped net: netem: fix error path for corrupted GSO frames macb: propagate errors when getting optional clocks xen/netback: fix error path of xenvif_connect_data() net: hns3: fix mis-counting IRQ vector numbers issue net: usb: lan78xx: Connect PHY before registering MAC vsock/virtio: discard packets if credit is not respected vsock/virtio: send a credit update when buffer size is changed mlxsw: spectrum_trap: Push Ethernet header before reporting trap net: ensure correct skb->tstamp in various fragmenters net: bcmgenet: reset 40nm EPHY on energy detect net: bcmgenet: soft reset 40nm EPHYs before MAC init net: phy: bcm7xxx: define soft_reset for 40nm EPHY net: bcmgenet: don't set phydev->link from MAC net: Update address for MediaTek ethernet driver in MAINTAINERS ipv4: fix race condition between route lookup and invalidation ...
2019-10-12Merge tag 'for-linus-5.4-rc3-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen fixes from Juergen Gross: - correct panic handling when running as a Xen guest - cleanup the Xen grant driver to remove printing a pointer being always NULL - remove a soon to be wrong call of of_dma_configure() * tag 'for-linus-5.4-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen: Stop abusing DT of_dma_configure API xen/grant-table: remove unnecessary printing x86/xen: Return from panic notifier
2019-10-10xen: Stop abusing DT of_dma_configure APIRob Herring
As the removed comments say, these aren't DT based devices. of_dma_configure() is going to stop allowing a NULL DT node and calling it will no longer work. The comment is also now out of date as of commit 9ab91e7c5c51 ("arm64: default to the direct mapping in get_arch_dma_ops"). Direct mapping is now the default rather than dma_dummy_ops. According to Stefano and Oleksandr, the only other part needed is setting the DMA masks and there's no reason to restrict the masks to 32-bits. So set the masks to 64 bits. Cc: Robin Murphy <robin.murphy@arm.com> Cc: Julien Grall <julien.grall@arm.com> Cc: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Cc: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Christoph Hellwig <hch@lst.de> Cc: xen-devel@lists.xenproject.org Signed-off-by: Rob Herring <robh@kernel.org> Acked-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2019-10-10xen/grant-table: remove unnecessary printingFuqian Huang
xen_auto_xlat_grant_frames.vaddr is definitely NULL in this case. So the address printing is unnecessary. Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2019-10-09net: add {READ|WRITE}_ONCE() annotations on ->rskq_accept_headEric Dumazet
reqsk_queue_empty() is called from inet_csk_listen_poll() while other cpus might write ->rskq_accept_head value. Use {READ|WRITE}_ONCE() to avoid compiler tricks and potential KCSAN splats. Fixes: fff1f3001cc5 ("tcp: add a spinlock to protect struct request_sock_queue") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-10-04Merge tag 'for-linus-5.4-rc2-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen fixes and cleanups from Juergen Gross: - a fix in the Xen balloon driver avoiding hitting a BUG_ON() in some cases, plus a follow-on cleanup series for that driver - a patch for introducing non-blocking EFI callbacks in Xen's EFI driver, plu a cleanup patch for Xen EFI handling merging the x86 and ARM arch specific initialization into the Xen EFI driver - a fix of the Xen xenbus driver avoiding a self-deadlock when cleaning up after a user process has died - a fix for Xen on ARM after removal of ZONE_DMA - a cleanup patch for avoiding build warnings for Xen on ARM * tag 'for-linus-5.4-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen/xenbus: fix self-deadlock after killing user process xen/efi: have a common runtime setup function arm: xen: mm: use __GPF_DMA32 for arm64 xen/balloon: Clear PG_offline in balloon_retrieve() xen/balloon: Mark pages PG_offline in balloon_append() xen/balloon: Drop __balloon_append() xen/balloon: Set pages PageOffline() in balloon_add_region() ARM: xen: unexport HYPERVISOR_platform_op function xen/efi: Set nonblocking callbacks
2019-10-02xen/xenbus: fix self-deadlock after killing user processJuergen Gross
In case a user process using xenbus has open transactions and is killed e.g. via ctrl-C the following cleanup of the allocated resources might result in a deadlock due to trying to end a transaction in the xenbus worker thread: [ 2551.474706] INFO: task xenbus:37 blocked for more than 120 seconds. [ 2551.492215] Tainted: P OE 5.0.0-29-generic #5 [ 2551.510263] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 2551.528585] xenbus D 0 37 2 0x80000080 [ 2551.528590] Call Trace: [ 2551.528603] __schedule+0x2c0/0x870 [ 2551.528606] ? _cond_resched+0x19/0x40 [ 2551.528632] schedule+0x2c/0x70 [ 2551.528637] xs_talkv+0x1ec/0x2b0 [ 2551.528642] ? wait_woken+0x80/0x80 [ 2551.528645] xs_single+0x53/0x80 [ 2551.528648] xenbus_transaction_end+0x3b/0x70 [ 2551.528651] xenbus_file_free+0x5a/0x160 [ 2551.528654] xenbus_dev_queue_reply+0xc4/0x220 [ 2551.528657] xenbus_thread+0x7de/0x880 [ 2551.528660] ? wait_woken+0x80/0x80 [ 2551.528665] kthread+0x121/0x140 [ 2551.528667] ? xb_read+0x1d0/0x1d0 [ 2551.528670] ? kthread_park+0x90/0x90 [ 2551.528673] ret_from_fork+0x35/0x40 Fix this by doing the cleanup via a workqueue instead. Reported-by: James Dingwall <james@dingwall.me.uk> Fixes: fd8aa9095a95c ("xen: optimize xenbus driver for multiple concurrent xenstore accesses") Cc: <stable@vger.kernel.org> # 4.11 Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2019-10-02xen/efi: have a common runtime setup functionJuergen Gross
Today the EFI runtime functions are setup in architecture specific code (x86 and arm), with the functions themselves living in drivers/xen as they are not architecture dependent. As the setup is exactly the same for arm and x86 move the setup to drivers/xen, too. This at once removes the need to make the single functions global visible. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> [boris: "Dropped EXPORT_SYMBOL_GPL(xen_efi_runtime_setup)"] Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2019-10-01xen/balloon: Clear PG_offline in balloon_retrieve()David Hildenbrand
Let's move the clearing to balloon_retrieve(). In bp_state increase_reservation(), we now clear the flag a little earlier than before, however, this should not matter for XEN. Suggested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2019-10-01xen/balloon: Mark pages PG_offline in balloon_append()David Hildenbrand
Let's move the __SetPageOffline() call which all callers perform into balloon_append(). In bp_state decrease_reservation(), pages are now marked PG_offline a little later than before, however, this should not matter for XEN. Suggested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2019-10-01xen/balloon: Drop __balloon_append()David Hildenbrand
Let's simply use balloon_append() directly. Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2019-10-01xen/balloon: Set pages PageOffline() in balloon_add_region()David Hildenbrand
We are missing a __SetPageOffline(), which is why we can get !PageOffline() pages onto the balloon list, where alloc_xenballooned_pages() will complain: page:ffffea0003e7ffc0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0xffffe00001000(reserved) raw: 000ffffe00001000 dead000000000100 dead000000000200 0000000000000000 raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000 page dumped because: VM_BUG_ON_PAGE(!PageOffline(page)) ------------[ cut here ]------------ kernel BUG at include/linux/page-flags.h:744! invalid opcode: 0000 [#1] SMP NOPTI Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> Tested-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> Fixes: 77c4adf6a6df ("xen/balloon: mark inflated pages PG_offline") Cc: stable@vger.kernel.org # v5.1+ Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2019-09-26Merge tag 'for-linus-5.4-rc1-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen update from Juergen Gross: "Only two small patches this time: - a small cleanup for swiotlb-xen - a fix for PCI initialization for some platforms" * tag 'for-linus-5.4-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen/pci: reserve MCFG areas earlier swiotlb-xen: Convert to use macro
2019-09-26xen/events: remove unlikely() from WARN() conditionDenis Efremov
"unlikely(WARN(x))" is excessive. WARN() already uses unlikely() internally. Link: http://lkml.kernel.org/r/20190829165025.15750-4-efremov@linux.com Signed-off-by: Denis Efremov <efremov@linux.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Joe Perches <joe@perches.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>