KarimAllah Ahmed 72a9b18629 xen: Remove event channel notification through Xen PCI platform device ... Ever since commit 254d1a3f02 ("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 38e20b07ef ("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 <boris.ostrovsky@oracle.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Juergen Gross <jgross@suse.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 <stefano.stabellini@eu.citrix.com> Cc: Julien Grall <julien.grall@citrix.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> Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>		2016-09-30 11:44:34 +01:00
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alpha
arc
arm	DeviceTree fixes for 4.8:	2016-08-18 19:31:08 -07:00
arm64	arm64: Fix shift warning in arch/arm64/mm/dump.c	2016-08-18 12:38:11 +01:00
avr32
blackfin
c6x
cris
frv
h8300	h8300: Add missing include file to asm/io.h	2016-08-13 08:53:56 -07:00
hexagon
ia64	Implements HARDENED_USERCOPY verification of copy_to_user/copy_from_user	2016-08-08 14:48:14 -07:00
m32r
m68k	m68knommu: fix user a5 register being overwritten	2016-08-08 12:38:47 +10:00
metag	metag: Drop show_mem() from mem_init()	2016-08-09 13:41:30 +01:00
microblaze
mips	MIPS: KVM: Propagate kseg0/mapped tlb fault errors	2016-08-12 12:01:30 +02:00
mn10300
nios2
openrisc
parisc	parisc: Fix order of EREFUSED define in errno.h	2016-08-20 13:33:53 +02:00
powerpc	KVM locks kvm_device list to prevent corruption on device creation.	2016-08-13 10:11:14 -07:00
s390	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux	2016-08-16 15:50:22 -07:00
score
sh
sparc	Implements HARDENED_USERCOPY verification of copy_to_user/copy_from_user	2016-08-08 14:48:14 -07:00
tile
um
unicore32	unicore32: mm: Add missing parameter to arch_vma_access_permitted	2016-08-13 08:53:18 -07:00
x86	xen: Remove event channel notification through Xen PCI platform device	2016-09-30 11:44:34 +01:00
xtensa
.gitignore
Kconfig	Implements HARDENED_USERCOPY verification of copy_to_user/copy_from_user	2016-08-08 14:48:14 -07:00