linux.git/drivers/xen, branch v4.9.30

xen: Revert commits da72ff5bfcb0 and 72a9b186292d

2017-05-14T12:00:22+00:00

commit 84d582d236dc1f9085e741affc72e9ba061a67c2 upstream.

Recent discussion (http://marc.info/?l=xen-devel&m=149192184523741)
established that commit 72a9b186292d ("xen: Remove event channel
notification through Xen PCI platform device") (and thus commit
da72ff5bfcb0 ("partially revert "xen: Remove event channel
notification through Xen PCI platform device"")) are unnecessary and,
in fact, prevent HVM guests from booting on Xen releases prior to 4.0

Therefore we revert both of those commits.

The summary of that discussion is below:

  Here is the brief summary of the current situation:

  Before the offending commit (72a9b186292):

  1) INTx does not work because of the reset_watches path.
  2) The reset_watches path is only taken if you have Xen > 4.0
  3) The Linux Kernel by default will use vector inject if the hypervisor
     support. So even INTx does not work no body running the kernel with
     Xen > 4.0 would notice. Unless he explicitly disabled this feature
     either in the kernel or in Xen (and this can only be disabled by
     modifying the code, not user-supported way to do it).

  After the offending commit (+ partial revert):

  1) INTx is no longer support for HVM (only for PV guests).
  2) Any HVM guest The kernel will not boot on Xen < 4.0 which does
     not have vector injection support. Since the only other mode
     supported is INTx which.

  So based on this summary, I think before commit (72a9b186292) we were
  in much better position from a user point of view.

Signed-off-by: Boris Ostrovsky 
Reviewed-by: Juergen Gross 
Cc: Boris Ostrovsky 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: "H. Peter Anvin" 
Cc: x86@kernel.org
Cc: Konrad Rzeszutek Wilk 
Cc: Bjorn Helgaas 
Cc: Stefano Stabellini 
Cc: Julien Grall 
Cc: Vitaly Kuznetsov 
Cc: Paul Gortmaker 
Cc: Ross Lagerwall 
Cc: xen-devel@lists.xenproject.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: Anthony Liguori 
Cc: KarimAllah Ahmed 
Signed-off-by: Juergen Gross 
Signed-off-by: Greg Kroah-Hartman

xen/acpi: upload PM state from init-domain to Xen

2017-03-30T07:41:26+00:00

commit 1914f0cd203c941bba72f9452c8290324f1ef3dc upstream.

This was broken in commit cd979883b9ed ("xen/acpi-processor:
fix enabling interrupts on syscore_resume"). do_suspend (from
xen/manage.c) and thus xen_resume_notifier never get called on
the initial-domain at resume (it is if running as guest.)

The rationale for the breaking change was that upload_pm_data()
potentially does blocking work in syscore_resume(). This patch
addresses the original issue by scheduling upload_pm_data() to
execute in workqueue context.

Cc: Stanislaw Gruszka 
Based-on-patch-by: Konrad Wilk 
Reviewed-by: Konrad Rzeszutek Wilk 
Reviewed-by: Stanislaw Gruszka 
Signed-off-by: Ankur Arora 
Signed-off-by: Boris Ostrovsky 
Signed-off-by: Greg Kroah-Hartman

swiotlb: Convert swiotlb_force from int to enum

2017-01-26T07:24:44+00:00

commit ae7871be189cb41184f1e05742b4a99e2c59774d upstream.

Convert the flag swiotlb_force from an int to an enum, to prepare for
the advent of more possible values.

Suggested-by: Konrad Rzeszutek Wilk 
Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Konrad Rzeszutek Wilk 
Signed-off-by: Greg Kroah-Hartman

xen/gntdev: Use VM_MIXEDMAP instead of VM_IO to avoid NUMA balancing

2017-01-06T09:40:17+00:00

commit 30faaafdfa0c754c91bac60f216c9f34a2bfdf7e upstream.

Commit 9c17d96500f7 ("xen/gntdev: Grant maps should not be subject to
NUMA balancing") set VM_IO flag to prevent grant maps from being
subjected to NUMA balancing.

It was discovered recently that this flag causes get_user_pages() to
always fail with -EFAULT.

check_vma_flags
__get_user_pages
__get_user_pages_locked
__get_user_pages_unlocked
get_user_pages_fast
iov_iter_get_pages
dio_refill_pages
do_direct_IO
do_blockdev_direct_IO
do_blockdev_direct_IO
ext4_direct_IO_read
generic_file_read_iter
aio_run_iocb

(which can happen if guest's vdisk has direct-io-safe option).

To avoid this let's use VM_MIXEDMAP flag instead --- it prevents
NUMA balancing just as VM_IO does and has no effect on
check_vma_flags().


Reported-by: Olaf Hering 
Suggested-by: Hugh Dickins 
Signed-off-by: Boris Ostrovsky 
Acked-by: Hugh Dickins 
Tested-by: Olaf Hering 
Signed-off-by: Juergen Gross 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'for-linus-4.9-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

2016-10-25T02:52:24+00:00

Pull xen fixes from David Vrabel:

 - advertise control feature flags in xenstore

 - fix x86 build when XEN_PVHVM is disabled

* tag 'for-linus-4.9-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xenbus: check return value of xenbus_scanf()
  xenbus: prefer list_for_each()
  x86: xen: move cpu_up functions out of ifdef
  xenbus: advertise control feature flags

xenbus: check return value of xenbus_scanf()

2016-10-24T15:08:21+00:00

Don't ignore errors here: Set backend state to unknown when
unsuccessful.

Signed-off-by: Jan Beulich 
Signed-off-by: David Vrabel

xenbus: prefer list_for_each()

2016-10-24T15:08:04+00:00

This is more efficient than list_for_each_safe() when list modification
is accompanied by breaking out of the loop.

Signed-off-by: Jan Beulich 
Reviewed-by: Juergen Gross 
Signed-off-by: David Vrabel

xenbus: advertise control feature flags

2016-10-24T14:48:40+00:00

The Xen docs specify several flags which a guest can set to advertise
which values of the xenstore control/shutdown key it will recognize.
This patch adds code to write all the relevant feature-flag keys.

Based-on-patch-by: Paul Durrant 
Signed-off-by: Juergen Gross 
Reviewed-by: David Vrabel 
Reviewed-by: Paul Durrant 
Signed-off-by: David Vrabel

Merge tag 'for-linus-4.9-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

2016-10-06T18:19:10+00:00

Pull xen updates from David Vrabel:
 "xen features and fixes for 4.9:

   - switch to new CPU hotplug mechanism

   - support driver_override in pciback

   - require vector callback for HVM guests (the alternate mechanism via
     the platform device has been broken for ages)"

* tag 'for-linus-4.9-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/x86: Update topology map for PV VCPUs
  xen/x86: Initialize per_cpu(xen_vcpu, 0) a little earlier
  xen/pciback: support driver_override
  xen/pciback: avoid multiple entries in slot list
  xen/pciback: simplify pcistub device handling
  xen: Remove event channel notification through Xen PCI platform device
  xen/events: Convert to hotplug state machine
  xen/x86: Convert to hotplug state machine
  x86/xen: add missing \n at end of printk warning message
  xen/grant-table: Use kmalloc_array() in arch_gnttab_valloc()
  xen: Make VPMU init message look less scary
  xen: rename xen_pmu_init() in sys-hypervisor.c
  hotplug: Prevent alloc/free of irq descriptors during cpu up/down (again)
  xen/x86: Move irq allocation from Xen smp_op.cpu_up()

xen/pciback: support driver_override

2016-09-30T10:49:02+00:00

Support the driver_override scheme introduced with commit 782a985d7af2
("PCI: Introduce new device binding path using pci_dev.driver_override")

As pcistub_probe() is called for all devices (it has to check for a
match based on the slot address rather than device type) it has to
check for driver_override set to "pciback" itself.

Up to now for assigning a pci device to pciback you need something like:

echo 0000:07:10.0 > /sys/bus/pci/devices/0000\:07\:10.0/driver/unbind
echo 0000:07:10.0 > /sys/bus/pci/drivers/pciback/new_slot
echo 0000:07:10.0 > /sys/bus/pci/drivers_probe

while with the patch you can use the same mechanism as for similar
drivers like pci-stub and vfio-pci:

echo pciback > /sys/bus/pci/devices/0000\:07\:10.0/driver_override
echo 0000:07:10.0 > /sys/bus/pci/devices/0000\:07\:10.0/driver/unbind
echo 0000:07:10.0 > /sys/bus/pci/drivers_probe

So e.g. libvirt doesn't need special handling for pciback.

Signed-off-by: Juergen Gross 
Signed-off-by: David Vrabel