linux-stable.git/drivers/xen, branch v5.10

xen: don't use page->lru for ZONE_DEVICE memory

2020-12-09T09:31:41+00:00

Commit 9e2369c06c8a18 ("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:  # 5.9
Fixes: 9e2369c06c8a18 ("xen: add helpers to allocate unpopulated memory")
Signed-off-by: Juergen Gross 
Reviewed-by: Boris Ostrovsky 
Reviewed-by: Jason Andryuk 
Signed-off-by: Juergen Gross

xen: add helpers for caching grant mapping pages

2020-12-09T09:31:37+00:00

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:  # 5.9
Signed-off-by: Juergen Gross 
Reviewed-by: Boris Ostrovsky 
Signed-off-by: Juergen Gross

swiotlb: remove the tbl_dma_addr argument to swiotlb_tbl_map_single

2020-11-02T15:10:39+00:00

The tbl_dma_addr argument is used to check the DMA boundary for the
allocations, and thus needs to be a dma_addr_t.  swiotlb-xen instead
passed a physical address, which could lead to incorrect results for
strange offsets.  Fix this by removing the parameter entirely and hard
code the DMA address for io_tlb_start instead.

Fixes: 91ffe4ad534a ("swiotlb-xen: introduce phys_to_dma/dma_to_phys translations")
Signed-off-by: Christoph Hellwig 
Reviewed-by: Stefano Stabellini 
Signed-off-by: Konrad Rzeszutek Wilk

Merge tag 'for-linus-5.10b-rc1c-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

2020-10-25T17:55:35+00:00

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

xen/events: unmask a fifo event channel only if it was masked

2020-10-23T10:41:25+00:00

Unmasking an event channel with fifo events channels being used can
require a hypercall to be made, so try to avoid that by checking
whether the event channel was really masked.

Suggested-by: Jan Beulich 
Signed-off-by: Juergen Gross 
Reviewed-by: Jan Beulich 
Link: https://lore.kernel.org/r/20201022094907.28560-5-jgross@suse.com
Signed-off-by: Boris Ostrovsky

xen/events: only register debug interrupt for 2-level events

2020-10-23T10:41:25+00:00

xen_debug_interrupt() is specific to 2-level event handling. So don't
register it with fifo event handling being active.

Signed-off-by: Juergen Gross 
Reviewed-by: Jan Beulich 
Link: https://lore.kernel.org/r/20201022094907.28560-4-jgross@suse.com
Signed-off-by: Boris Ostrovsky

xen/events: make struct irq_info private to events_base.c

2020-10-23T10:41:25+00:00

The struct irq_info of Xen's event handling is used only for two
evtchn_ops functions outside of events_base.c. Those two functions
can easily be switched to avoid that usage.

This allows to make struct irq_info and its related access functions
private to events_base.c.

Signed-off-by: Juergen Gross 
Reviewed-by: Jan Beulich 
Link: https://lore.kernel.org/r/20201022094907.28560-3-jgross@suse.com
Signed-off-by: Boris Ostrovsky

xen: remove no longer used functions

2020-10-23T10:41:25+00:00

With the switch to the lateeoi model for interdomain event channels
some functions are no longer in use. Remove them.

Suggested-by: Jan Beulich 
Signed-off-by: Juergen Gross 
Reviewed-by: Jan Beulich 
Link: https://lore.kernel.org/r/20201022094907.28560-2-jgross@suse.com
Signed-off-by: Boris Ostrovsky

Merge tag 'for-linus-5.10b-rc1b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

2020-10-20T16:24:01+00:00

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

xen/events: block rogue events for some time

2020-10-20T08:22:19+00:00

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 
Reviewed-by: Jan Beulich 
Reviewed-by: Stefano Stabellini 
Reviewed-by: Wei Liu