After Commit 3499ba8198 ("xen: Fix event channel callback via
INTX/GSI"), xenbus_probe() will be called too early on Arm. This will
recent to a guest hang during boot.
If the hang wasn't there, we would have ended up to call
xenbus_probe() twice (the second time is in xenbus_probe_initcall()).
We don't need to initialize xenbus_probe() early for Arm guest.
Therefore, the call in xen_guest_init() is now removed.
After this change, there is no more external caller for xenbus_probe().
So the function is turned to a static one. Interestingly there were two
prototypes for it.
Cc: stable@vger.kernel.org
Fixes: 3499ba8198 ("xen: Fix event channel callback via INTX/GSI")
Reported-by: Ian Jackson <iwj@xenproject.org>
Signed-off-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Link: https://lore.kernel.org/r/20210210170654.5377-1-julien@xen.org
Signed-off-by: Juergen Gross <jgross@suse.com>
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>
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>
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>
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>
Commit 9e2369c06c ("xen: add helpers to allocate unpopulated
memory") introduced usage of ZONE_DEVICE memory for foreign memory
mappings.
Unfortunately this collides with using page->lru for Xen backend
private page caches.
Fix that by using page->zone_device_data instead.
Cc: <stable@vger.kernel.org> # 5.9
Fixes: 9e2369c06c ("xen: add helpers to allocate unpopulated memory")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovksy@oracle.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Instead of having similar helpers in multiple backend drivers use
common helpers for caching pages allocated via gnttab_alloc_pages().
Make use of those helpers in blkback and scsiback.
Cc: <stable@vger.kernel.org> # 5.9
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovksy@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Pull more xen updates from Juergen Gross:
- a series for the Xen pv block drivers adding module parameters for
better control of resource usge
- a cleanup series for the Xen event driver
* tag 'for-linus-5.10b-rc1c-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
Documentation: add xen.fifo_events kernel parameter description
xen/events: unmask a fifo event channel only if it was masked
xen/events: only register debug interrupt for 2-level events
xen/events: make struct irq_info private to events_base.c
xen: remove no longer used functions
xen-blkfront: Apply changed parameter name to the document
xen-blkfront: add a parameter for disabling of persistent grants
xen-blkback: add a parameter for disabling of persistent grants
Pull more xen updates from Juergen Gross:
- A single patch to fix the Xen security issue XSA-331 (malicious
guests can DoS dom0 by triggering NULL-pointer dereferences or access
to stale data).
- A larger series to fix the Xen security issue XSA-332 (malicious
guests can DoS dom0 by sending events at high frequency leading to
dom0's vcpus being busy in IRQ handling for elongated times).
* tag 'for-linus-5.10b-rc1b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen/events: block rogue events for some time
xen/events: defer eoi in case of excessive number of events
xen/events: use a common cpu hotplug hook for event channels
xen/events: switch user event channels to lateeoi model
xen/pciback: use lateeoi irq binding
xen/pvcallsback: use lateeoi irq binding
xen/scsiback: use lateeoi irq binding
xen/netback: use lateeoi irq binding
xen/blkback: use lateeoi irq binding
xen/events: add a new "late EOI" evtchn framework
xen/events: fix race in evtchn_fifo_unmask()
xen/events: add a proper barrier to 2-level uevent unmasking
xen/events: avoid removing an event channel while handling it
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>
Pull xen updates from Juergen Gross:
"A small series for fixing a problem with Xen PVH guests when running
as backends (e.g. as dom0).
Mapping other guests' memory is now working via ZONE_DEVICE, thus not
requiring to abuse the memory hotplug functionality for that purpose"
* tag 'for-linus-5.9-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen: add helpers to allocate unpopulated memory
memremap: rename MEMORY_DEVICE_DEVDAX to MEMORY_DEVICE_GENERIC
xen/balloon: add header guard
Pull xen fixes from Juergen Gross:
"Two fixes for Xen: one needed for ongoing work to support virtio with
Xen, and one for a corner case in IRQ handling with Xen"
* tag 'for-linus-5.9-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
arm/xen: Add misuse warning to virt_to_gfn
xen/xenbus: Fix granting of vmalloc'd memory
XEN uses irqdesc::irq_data_common::handler_data to store a per interrupt XEN data pointer which contains XEN specific information.
Pull more xen updates from Juergen Gross:
- Remove support for running as 32-bit Xen PV-guest.
32-bit PV guests are rarely used, are lacking security fixes for
Meltdown, and can be easily replaced by PVH mode. Another series for
doing more cleanup will follow soon (removal of 32-bit-only pvops
functionality).
- Fixes and additional features for the Xen display frontend driver.
* tag 'for-linus-5.9-rc1b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
drm/xen-front: Pass dumb buffer data offset to the backend
xen: Sync up with the canonical protocol definition in Xen
drm/xen-front: Add YUYV to supported formats
drm/xen-front: Fix misused IS_ERR_OR_NULL checks
xen/gntdev: Fix dmabuf import with non-zero sgt offset
x86/xen: drop tests for highmem in pv code
x86/xen: eliminate xen-asm_64.S
x86/xen: remove 32-bit Xen PV guest support
This is the sync up with the canonical definition of the
display protocol in Xen.
1. Add protocol version as an integer
Version string, which is in fact an integer, is hard to handle in the
code that supports different protocol versions. To simplify that
also add the version as an integer.
2. Pass buffer offset with XENDISPL_OP_DBUF_CREATE
There are cases when display data buffer is created with non-zero
offset to the data start. Handle such cases and provide that offset
while creating a display buffer.
3. Add XENDISPL_OP_GET_EDID command
Add an optional request for reading Extended Display Identification
Data (EDID) structure which allows better configuration of the
display connectors over the configuration set in XenStore.
With this change connectors may have multiple resolutions defined
with respect to detailed timing definitions and additional properties
normally provided by displays.
If this request is not supported by the backend then visible area
is defined by the relevant XenStore's "resolution" property.
If backend provides extended display identification data (EDID) with
XENDISPL_OP_GET_EDID request then EDID values must take precedence
over the resolutions defined in XenStore.
4. Bump protocol version to 2.
Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20200813062113.11030-5-andr2000@gmail.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Pull xen updates from Juergen Gross:
- two trivial comment fixes
- a small series for the Xen balloon driver fixing some issues
- a series of the Xen privcmd driver targeting elimination of using
get_user_pages*() in this driver
- a series for the Xen swiotlb driver cleaning it up and adding support
for letting the kernel run as dom0 on Rpi4
* tag 'for-linus-5.9-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen/arm: call dma_to_phys on the dma_addr_t parameter of dma_cache_maint
xen/arm: introduce phys/dma translations in xen_dma_sync_for_*
swiotlb-xen: introduce phys_to_dma/dma_to_phys translations
swiotlb-xen: remove XEN_PFN_PHYS
swiotlb-xen: add struct device * parameter to is_xen_swiotlb_buffer
swiotlb-xen: add struct device * parameter to xen_dma_sync_for_device
swiotlb-xen: add struct device * parameter to xen_dma_sync_for_cpu
swiotlb-xen: add struct device * parameter to xen_bus_to_phys
swiotlb-xen: add struct device * parameter to xen_phys_to_bus
swiotlb-xen: remove start_dma_addr
swiotlb-xen: use vmalloc_to_page on vmalloc virt addresses
Revert "xen/balloon: Fix crash when ballooning on x86 32 bit PAE"
xen/balloon: make the balloon wait interruptible
xen/balloon: fix accounting in alloc_xenballooned_pages error path
xen: hypercall.h: fix duplicated word
xen/gntdev: gntdev.h: drop a duplicated word
xen/privcmd: Convert get_user_pages*() to pin_user_pages*()
xen/privcmd: Mark pages as dirty
xen/privcmd: Corrected error handling path
xen_dma_sync_for_cpu, xen_dma_sync_for_device, xen_arch_need_swiotlb are
getting called passing dma addresses. On some platforms dma addresses
could be different from physical addresses. Before doing any operations
on these addresses we need to convert them back to physical addresses
using dma_to_phys.
Move the arch_sync_dma_for_cpu and arch_sync_dma_for_device calls from
xen_dma_sync_for_cpu/device to swiotlb-xen.c, and add a call dma_to_phys
to do address translations there.
dma_cache_maint is fixed by the next patch.
Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com>
Tested-by: Corey Minyard <cminyard@mvista.com>
Tested-by: Roman Shaposhnik <roman@zededa.com>
Acked-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20200710223427.6897-10-sstabellini@kernel.org
Signed-off-by: Juergen Gross <jgross@suse.com>
The patch adds a new extra type to be able to diffirentiate
between RX responses on xen-netfront side with the adjusted offset
required for XDP processing.
The offset value from a guest is passed via xenstore.
Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Julien Grall
David Woodhouse
SeongJae Park
Juergen Gross
Linus Torvalds
Masami Hiramatsu
Roger Pau Monne
Simon Leiner
Oleksandr Andrushchenko
Stefano Stabellini
Denis Kirjanov