linux/include/xen
Boris Ostrovsky 5d7ab8339a xen: Revert commits da72ff5bfc and 72a9b18629
commit 84d582d236 upstream.

Recent discussion (http://marc.info/?l=xen-devel&m=149192184523741)
established that commit 72a9b18629 ("xen: Remove event channel
notification through Xen PCI platform device") (and thus commit
da72ff5bfc ("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 (72a9b18629):

  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 (72a9b18629) we were
  in much better position from a user point of view.

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Julien Grall <julien.grall@arm.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Ross Lagerwall <ross.lagerwall@citrix.com>
Cc: xen-devel@lists.xenproject.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: Anthony Liguori <aliguori@amazon.com>
Cc: KarimAllah Ahmed <karahmed@amazon.de>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2017-05-14 14:00:22 +02:00
..
interface xen: Sync xen header 2016-09-05 13:52:37 +02:00
acpi.h xen / ACPI: notify xen when reduced hardware sleep is available 2013-07-31 14:22:35 +02:00
balloon.h xen/balloon: use hotplugged pages for foreign mappings etc. 2015-10-23 14:20:05 +01:00
events.h xen/events: Support event channel rebind on ARM 2015-08-20 12:24:15 +01:00
features.h xen: Core Xen implementation 2007-07-18 08:47:42 -07:00
grant_table.h xen/grant-table: Add an helper to iterate over a specific number of grants 2015-10-23 14:20:46 +01:00
hvc-console.h treewide: use __printf not __attribute__((format(printf,...))) 2011-10-31 17:30:54 -07:00
hvm.h xen: Convert printks to pr_<level> 2013-06-28 11:19:58 -04:00
page.h xen: Fix page <-> pfn conversion on 32 bit systems 2016-04-06 11:18:17 +01:00
platform_pci.h xen/pvhvm: Remove the xen_platform_pci int. 2014-01-03 14:54:53 -05:00
swiotlb-xen.h dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
tmem.h xen: tmem: enable Xen tmem shim to be built/loaded as a module 2013-04-30 17:04:01 -07:00
xen-ops.h xen: change the type of xen_vcpu_id to uint32_t 2016-08-24 18:17:27 +01:00
xen.h xen: Revert commits da72ff5bfc and 72a9b18629 2017-05-14 14:00:22 +02:00
xenbus.h xen/xenbus: Rename *RING_PAGE* to *RING_GRANT* 2015-10-23 14:20:46 +01:00
xenbus_dev.h xenbus: Add support for xenbus backend in stub domain 2012-05-21 09:53:18 -04:00