linux-stable.git/include/xen, branch linux-4.10.y

xen: Revert commits da72ff5bfcb0 and 72a9b186292d

2017-05-14T12:08:30+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

Merge tag 'for-linus-4.10-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

2016-12-14T00:07:55+00:00

Pull xen updates from Juergen Gross:
 "Xen features and fixes for 4.10

  These are some fixes, a move of some arm related headers to share them
  between arm and arm64 and a series introducing a helper to make code
  more readable.

  The most notable change is David stepping down as maintainer of the
  Xen hypervisor interface. This results in me sending you the pull
  requests for Xen related code from now on"

* tag 'for-linus-4.10-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (29 commits)
  xen/balloon: Only mark a page as managed when it is released
  xenbus: fix deadlock on writes to /proc/xen/xenbus
  xen/scsifront: don't request a slot on the ring until request is ready
  xen/x86: Increase xen_e820_map to E820_X_MAX possible entries
  x86: Make E820_X_MAX unconditionally larger than E820MAX
  xen/pci: Bubble up error and fix description.
  xen: xenbus: set error code on failure
  xen: set error code on failures
  arm/xen: Use alloc_percpu rather than __alloc_percpu
  arm/arm64: xen: Move shared architecture headers to include/xen/arm
  xen/events: use xen_vcpu_id mapping for EVTCHNOP_status
  xen/gntdev: Use VM_MIXEDMAP instead of VM_IO to avoid NUMA balancing
  xen-scsifront: Add a missing call to kfree
  MAINTAINERS: update XEN HYPERVISOR INTERFACE
  xenfs: Use proc_create_mount_point() to create /proc/xen
  xen-platform: use builtin_pci_driver
  xen-netback: fix error handling output
  xen: make use of xenbus_read_unsigned() in xenbus
  xen: make use of xenbus_read_unsigned() in xen-pciback
  xen: make use of xenbus_read_unsigned() in xen-fbfront
  ...

Merge branch 'stable/for-linus-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb

2016-12-13T23:52:23+00:00

Pull swiotlb updates from Konrad Rzeszutek Wilk:

 - minor fixes (rate limiting), remove certain functions

 - support for DMA_ATTR_SKIP_CPU_SYNC which is an optimization
   in the DMA API

* 'stable/for-linus-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb:
  swiotlb: Minor fix-ups for DMA_ATTR_SKIP_CPU_SYNC support
  swiotlb: Add support for DMA_ATTR_SKIP_CPU_SYNC
  swiotlb-xen: Enforce return of DMA_ERROR_CODE in mapping function
  swiotlb: Drop unused functions swiotlb_map_sg and swiotlb_unmap_sg
  swiotlb: Rate-limit printing when running out of SW-IOMMU space

arm/arm64: xen: Move shared architecture headers to include/xen/arm

2016-12-02T19:49:55+00:00

ARM and arm64 Xen ports share a number of headers, leading to
packaging issues when these headers needs to be exported, as it
breaks the reasonable requirement that an architecture port
has self-contained headers.

Fix the issue by moving the 5 header files to include/xen/arm,
and keep local placeholders to include the relevant files.

Signed-off-by: Marc Zyngier 
Reviewed-by: Stefano Stabellini

swiotlb-xen: Enforce return of DMA_ERROR_CODE in mapping function

2016-11-07T20:06:32+00:00

The mapping function should always return DMA_ERROR_CODE when a mapping has
failed as this is what the DMA API expects when a DMA error has occurred.
The current function for mapping a page in Xen was returning either
DMA_ERROR_CODE or 0 depending on where it failed.

On x86 DMA_ERROR_CODE is 0, but on other architectures such as ARM it is
~0. We need to make sure we return the same error value if either the
mapping failed or the device is not capable of accessing the mapping.

If we are returning DMA_ERROR_CODE as our error value we can drop the
function for checking the error code as the default is to compare the
return value against DMA_ERROR_CODE if no function is defined.

Cc: Konrad Rzeszutek Wilk 
Signed-off-by: Alexander Duyck 
Signed-off-by: Konrad Rzeszutek Wilk

xen: introduce xenbus_read_unsigned()

2016-11-07T12:55:02+00:00

There are multiple instances of code reading an optional unsigned
parameter from Xenstore via xenbus_scanf(). Instead of repeating the
same code over and over add a service function doing the job.

Signed-off-by: Juergen Gross 
Reviewed-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: Remove event channel notification through Xen PCI platform device

2016-09-30T10:44:34+00:00

Ever since commit 254d1a3f02eb ("xen/pv-on-hvm kexec: shutdown watches
from old kernel") using the INTx interrupt from Xen PCI platform
device for event channel notification would just lockup the guest
during bootup.  postcore_initcall now calls xs_reset_watches which
will eventually try to read a value from XenStore and will get stuck
on read_reply at XenBus forever since the platform driver is not
probed yet and its INTx interrupt handler is not registered yet. That
means that the guest can not be notified at this moment of any pending
event channels and none of the per-event handlers will ever be invoked
(including the XenStore one) and the reply will never be picked up by
the kernel.

The exact stack where things get stuck during xenbus_init:

-xenbus_init
 -xs_init
  -xs_reset_watches
   -xenbus_scanf
    -xenbus_read
     -xs_single
      -xs_single
       -xs_talkv

Vector callbacks have always been the favourite event notification
mechanism since their introduction in commit 38e20b07efd5 ("x86/xen:
event channels delivery on HVM.") and the vector callback feature has
always been advertised for quite some time by Xen that's why INTx was
broken for several years now without impacting anyone.

Luckily this also means that event channel notification through INTx
is basically dead-code which can be safely removed without impacting
anybody since it has been effectively disabled for more than 4 years
with nobody complaining about it (at least as far as I'm aware of).

This commit removes event channel notification through Xen PCI
platform device.

Cc: Boris Ostrovsky 
Cc: David Vrabel 
Cc: Juergen Gross 
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 
Signed-off-by: KarimAllah Ahmed 
Reviewed-by: Boris Ostrovsky 
Signed-off-by: David Vrabel

xen: Sync xen header

2016-09-05T11:52:37+00:00

Import the actual version of include/xen/interface/sched.h from Xen.

Signed-off-by: Juergen Gross 
Signed-off-by: Peter Zijlstra (Intel) 
Acked-by: David Vrabel 
Cc: Douglas_Warzecha@dell.com
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: akataria@vmware.com
Cc: boris.ostrovsky@oracle.com
Cc: chrisw@sous-sol.org
Cc: hpa@zytor.com
Cc: jdelvare@suse.com
Cc: jeremy@goop.org
Cc: linux@roeck-us.net
Cc: pali.rohar@gmail.com
Cc: rusty@rustcorp.com.au
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1472453327-19050-2-git-send-email-jgross@suse.com
Signed-off-by: Ingo Molnar

xen: change the type of xen_vcpu_id to uint32_t

2016-08-24T17:17:27+00:00

We pass xen_vcpu_id mapping information to hypercalls which require
uint32_t type so it would be cleaner to have it as uint32_t. The
initializer to -1 can be dropped as we always do the mapping before using
it and we never check the 'not set' value anyway.

Signed-off-by: Vitaly Kuznetsov 
Signed-off-by: David Vrabel