linux/arch
Jeremy Fitzhardinge 9f79991d41 xen: deal with stale cr3 values when unpinning pagetables
When a pagetable is no longer in use, it must be unpinned so that its
pages can be freed.  However, this is only possible if there are no
stray uses of the pagetable.  The code currently deals with all the
usual cases, but there's a rare case where a vcpu is changing cr3, but
is doing so lazily, and the change hasn't actually happened by the time
the pagetable is unpinned, even though it appears to have been completed.

This change adds a second per-cpu cr3 variable - xen_current_cr3 -
which tracks the actual state of the vcpu cr3.  It is only updated once
the actual hypercall to set cr3 has been completed.  Other processors
wishing to unpin a pagetable can check other vcpu's xen_current_cr3
values to see if any cross-cpu IPIs are needed to clean things up.

[ Stable folks: 2.6.23 bugfix ]

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Stable Kernel <stable@kernel.org>
2007-10-16 11:51:30 -07:00
..
alpha alpha: -Werror fixes for sys_titan.c 2007-08-11 15:47:42 -07:00
arm Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/cpufreq 2007-10-12 15:42:01 -07:00
avr32 [AVR32] Fix random segfault with preemption 2007-10-11 13:32:56 +02:00
blackfin Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/usb-2.6 2007-10-12 15:49:10 -07:00
cris ide: fix hidden dependencies on CONFIG_IDE_GENERIC 2007-08-20 22:42:54 +02:00
frv FRV: connect up fallocate 2007-08-11 15:47:40 -07:00
h8300 H8/300: Fix misnamed "CONFIG_BLKDEV_RESERVE_ADDRESS" Kconfig variable 2007-09-11 17:21:20 -07:00
i386 Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/pci-2.6 2007-10-12 15:50:23 -07:00
ia64 Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/driver-2.6 2007-10-12 15:49:37 -07:00
m32r m32r: Rename STI/CLI macros 2007-09-06 11:10:56 +09:00
m68k m68k(nommu): add missing syscalls 2007-09-11 17:21:20 -07:00
m68knommu m68k(nommu): add missing syscalls 2007-09-11 17:21:20 -07:00
mips Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6 2007-10-11 19:40:14 -07:00
parisc [PARISC] Add NOTES section 2007-08-27 00:29:25 -04:00
powerpc Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/driver-2.6 2007-10-12 15:49:37 -07:00
ppc [POWERPC] Remove redundant reference to non-existent CONFIG_BOOTIMG 2007-10-09 21:02:00 +10:00
s390 [S390] pfault: Fix alignment of parameter list. 2007-10-12 16:13:11 +02:00
sh Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/cpufreq 2007-10-12 15:42:01 -07:00
sh64 sh64: arch/sh64/kernel/setup.c: duplicate include removal. 2007-08-12 12:18:54 +09:00
sparc [SPARC]: Fix EBUS use of uninitialized variable. 2007-09-27 13:09:28 -07:00
sparc64 Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/cpufreq 2007-10-12 15:42:01 -07:00
um i386/x86_64: move headers to include/asm-x86 2007-10-11 11:20:03 +02:00
v850 PTRACE_POKEDATA consolidation 2007-07-17 10:23:03 -07:00
x86 xen: deal with stale cr3 values when unpinning pagetables 2007-10-16 11:51:30 -07:00
x86_64 Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/pci-2.6 2007-10-12 15:50:23 -07:00
xtensa xtensa process.c must #include <linux/fs.h> 2007-08-30 09:58:22 -07:00