linux-stable.git/drivers/xen, branch v5.5.8

xen: Enable interrupts when calling _cond_resched()

2020-02-28T16:23:44+00:00

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 
Link: https://lore.kernel.org/r/878skypjrh.fsf@nanos.tec.linutronix.de
Reviewed-by: Juergen Gross 
Signed-off-by: Boris Ostrovsky 
Signed-off-by: Greg Kroah-Hartman

xen/gntdev: Do not use mm notifiers with autotranslating guests

2020-02-11T12:37:06+00:00

commit 9293724192a73f49c722e9685d45649c6df67dfe upstream.

Commit d3eeb1d77c5d ("xen/gntdev: use mmu_interval_notifier_insert")
missed a test for use_ptemod when calling mmu_interval_read_begin(). Fix
that.

Fixes: d3eeb1d77c5d ("xen/gntdev: use mmu_interval_notifier_insert")
CC: stable@vger.kernel.org # 5.5
Reported-by: Ilpo Järvinen 
Tested-by: Ilpo Järvinen 
Signed-off-by: Boris Ostrovsky 
Reviewed-by: Jason Gunthorpe 
Acked-by: Juergen Gross 
Signed-off-by: Greg Kroah-Hartman

xen/balloon: Support xend-based toolstack take two

2020-02-11T12:37:06+00:00

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 
Reviewed-by: Boris Ostrovsky 
Cc:  # 4.13
Signed-off-by: Boris Ostrovsky 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'for-linus-5.5b-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

2019-12-21T14:24:56+00:00

Pull xen fixes from Juergen Gross:
 "This contains two cleanup patches and a small series for supporting
  reloading the Xen block backend driver"

* tag 'for-linus-5.5b-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/grant-table: remove multiple BUG_ON on gnttab_interface
  xen-blkback: support dynamic unbind/bind
  xen/interface: re-define FRONT/BACK_RING_ATTACH()
  xenbus: limit when state is forced to closed
  xenbus: move xenbus_dev_shutdown() into frontend code...
  xen/blkfront: Adjust indentation in xlvbd_alloc_gendisk

xen/grant-table: remove multiple BUG_ON on gnttab_interface

2019-12-20T12:54:56+00:00

gnttab_request_version() always sets the gnttab_interface variable
and the assertions to check for empty gnttab_interface is unnecessary.
The patch eliminates multiple such assertions.

Signed-off-by: Aditya Pakki 
Reviewed-by: Juergen Gross 
Signed-off-by: Juergen Gross

xenbus: limit when state is forced to closed

2019-12-20T12:44:38+00:00

If a driver probe() fails then leave the xenstore state alone. There is no
reason to modify it as the failure may be due to transient resource
allocation issues and hence a subsequent probe() may succeed.

If the driver supports re-binding then only force state to closed during
remove() only in the case when the toolstack may need to clean up. This can
be detected by checking whether the state in xenstore has been set to
closing prior to device removal.

NOTE: Re-bind support is indicated by new boolean in struct xenbus_driver,
      which defaults to false. Subsequent patches will add support to
      some backend drivers.

Signed-off-by: Paul Durrant 
Reviewed-by: Juergen Gross 
Signed-off-by: Juergen Gross

xenbus: move xenbus_dev_shutdown() into frontend code...

2019-12-20T12:44:35+00:00

...and make it static

xenbus_dev_shutdown() is seemingly intended to cause clean shutdown of PV
frontends when a guest is rebooted. Indeed the function waits for a
conpletion which is only set by a call to xenbus_frontend_closed().

This patch removes the shutdown() method from backends and moves
xenbus_dev_shutdown() from xenbus_probe.c into xenbus_probe_frontend.c,
renaming it appropriately and making it static.

NOTE: In the case where the backend is running in a driver domain, the
      toolstack should have already terminated any frontends that may be
      using it (since Xen does not support re-startable PV driver domains)
      so xenbus_dev_shutdown() should never be called.

Signed-off-by: Paul Durrant 
Reviewed-by: Juergen Gross 
Signed-off-by: Juergen Gross

Merge tag 'for-linus-5.5b-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

2019-12-15T20:24:44+00:00

Pull xen fixes from Juergen Gross:
 "Two fixes: one for a resource accounting bug in some configurations
  and a fix for another patch which went into rc1"

* tag 'for-linus-5.5b-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/balloon: fix ballooned page accounting without hotplug enabled
  xen-blkback: prevent premature module unload

xen/balloon: fix ballooned page accounting without hotplug enabled

2019-12-13T07:39:52+00:00

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

Merge tag 'for-linus-5.5b-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

2019-12-07T22:49:20+00:00

Pull more xen updates from Juergen Gross:

 - a patch to fix a build warning

 - a cleanup of no longer needed code in the Xen event handling

 - a small series for the Xen grant driver avoiding high order
   allocations and replacing an insane global limit by a per-call one

 - a small series fixing Xen frontend/backend module referencing

* tag 'for-linus-5.5b-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen-blkback: allow module to be cleanly unloaded
  xen/xenbus: reference count registered modules
  xen/gntdev: switch from kcalloc() to kvcalloc()
  xen/gntdev: replace global limit of mapped pages by limit per call
  xen/gntdev: remove redundant non-zero check on ret
  xen/events: remove event handling recursion detection