linux/arch/x86/xen
Olaf Hering 9d02b43dee xen PVonHVM: use E820_Reserved area for shared_info
This is a respin of 00e37bdb01
("xen PVonHVM: move shared_info to MMIO before kexec").

Currently kexec in a PVonHVM guest fails with a triple fault because the
new kernel overwrites the shared info page. The exact failure depends on
the size of the kernel image. This patch moves the pfn from RAM into an
E820 reserved memory area.

The pfn containing the shared_info is located somewhere in RAM. This will
cause trouble if the current kernel is doing a kexec boot into a new
kernel. The new kernel (and its startup code) can not know where the pfn
is, so it can not reserve the page. The hypervisor will continue to update
the pfn, and as a result memory corruption occours in the new kernel.

The toolstack marks the memory area FC000000-FFFFFFFF as reserved in the
E820 map. Within that range newer toolstacks (4.3+) will keep 1MB
starting from FE700000 as reserved for guest use. Older Xen4 toolstacks
will usually not allocate areas up to FE700000, so FE700000 is expected
to work also with older toolstacks.

In Xen3 there is no reserved area at a fixed location. If the guest is
started on such old hosts the shared_info page will be placed in RAM. As
a result kexec can not be used.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-11-02 11:04:01 -04:00
..
apic.c xen/apic/xenbus/swiotlb/pcifront/grant/tmem: Make functions or variables static. 2012-08-21 14:50:03 -04:00
debugfs.c debugfs: Add support to print u32 array in debugfs 2012-04-17 00:18:36 -04:00
debugfs.h debugfs: Add support to print u32 array in debugfs 2012-04-17 00:18:36 -04:00
enlighten.c xen PVonHVM: use E820_Reserved area for shared_info 2012-11-02 11:04:01 -04:00
grant-table.c Merge commit 'v3.2-rc3' into stable/for-linus-3.3 2011-12-20 17:01:18 -05:00
irq.c xen/arm: receive Xen events on ARM 2012-09-14 13:37:32 +00:00
Kconfig xen: Make XEN_MAX_DOMAIN_MEMORY have more sensible defaults 2011-11-21 17:14:46 -05:00
Makefile xen/x86: Implement x86_apic_ops 2012-05-01 14:50:33 -04:00
mmu.c Feature: 2012-10-12 22:20:28 +09:00
mmu.h xen: make a pile of mmu pvop functions static 2011-05-20 14:25:24 -07:00
multicalls.c xen/multicall: move *idx fields to start of mc_buffer 2011-07-18 15:43:46 -07:00
multicalls.h xen: use this_cpu_xxx replace percpu_xxx funcs 2012-01-24 12:20:24 -05:00
p2m.c Features: 2012-10-02 22:09:10 -07:00
pci-swiotlb-xen.c Merge branch 'stable/late-swiotlb.v3.3' into stable/for-linus-3.7 2012-09-22 20:01:24 -04:00
platform-pci-unplug.c xen/apic/xenbus/swiotlb/pcifront/grant/tmem: Make functions or variables static. 2012-08-21 14:50:03 -04:00
setup.c Features: 2012-10-02 22:09:10 -07:00
smp.c x86/smp: Don't ever patch back to UP if we unplug cpus 2012-08-23 10:45:13 +02:00
smp.h xen: implement apic ipi interface 2012-05-07 15:33:15 -04:00
spinlock.c debugfs: Add support to print u32 array in debugfs 2012-04-17 00:18:36 -04:00
suspend.c xen PVonHVM: use E820_Reserved area for shared_info 2012-11-02 11:04:01 -04:00
time.c Merge branch 'upstream/xen-settime' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen 2011-11-06 20:15:05 -08:00
trace.c xen/trace: Fix compile error when CONFIG_XEN_PRIVILEGED_GUEST is not set 2011-08-05 09:43:02 -04:00
vdso.h
vga.c xen/vga: add the xen EFI video mode support 2012-09-24 09:28:57 -04:00
xen-asm_32.S x86, extable: Remove open-coded exception table entries in arch/x86/xen/xen-asm_32.S 2012-04-20 13:51:39 -07:00
xen-asm_64.S xen: use iret for return from 64b kernel to 32b usermode 2009-12-03 11:14:54 -08:00
xen-asm.h xen: make direct versions of irq_enable/disable/save/restore to common code 2009-02-04 16:59:04 -08:00
xen-asm.S xen: correctly check for pending events when restoring irq flags 2012-04-27 16:04:21 -04:00
xen-head.S xen/perf: Define .glob for the different hypercalls. 2012-07-30 14:27:48 -04:00
xen-ops.h xen PVonHVM: use E820_Reserved area for shared_info 2012-11-02 11:04:01 -04:00