Juergen Gross ab24507cfa xen: avoid another early crash of memory limited dom0 ... Commit b1c9f169047b ("xen: split counting of extra memory pages...") introduced an error when dom0 was started with limited memory occurring only on some hardware. The problem arises in case dom0 is started with initial memory and maximum memory being the same. The kernel must be configured without CONFIG_XEN_BALLOON_MEMORY_HOTPLUG for the problem to happen. If all of this is true and the E820 map of the machine is sparse (some areas are not covered) then the machine might crash early in the boot process. An example E820 map triggering the problem looks like this: [ 0.000000] e820: BIOS-provided physical RAM map: [ 0.000000] BIOS-e820: [mem 0x0000000000000000-0x000000000009d7ff] usable [ 0.000000] BIOS-e820: [mem 0x000000000009d800-0x000000000009ffff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000000e0000-0x00000000000fffff] reserved [ 0.000000] BIOS-e820: [mem 0x0000000000100000-0x00000000cf7fafff] usable [ 0.000000] BIOS-e820: [mem 0x00000000cf7fb000-0x00000000cf95ffff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000cf960000-0x00000000cfb62fff] ACPI NVS [ 0.000000] BIOS-e820: [mem 0x00000000cfb63000-0x00000000cfd14fff] usable [ 0.000000] BIOS-e820: [mem 0x00000000cfd15000-0x00000000cfd61fff] ACPI NVS [ 0.000000] BIOS-e820: [mem 0x00000000cfd62000-0x00000000cfd6cfff] ACPI data [ 0.000000] BIOS-e820: [mem 0x00000000cfd6d000-0x00000000cfd6ffff] ACPI NVS [ 0.000000] BIOS-e820: [mem 0x00000000cfd70000-0x00000000cfd70fff] usable [ 0.000000] BIOS-e820: [mem 0x00000000cfd71000-0x00000000cfea8fff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000cfea9000-0x00000000cfeb9fff] ACPI NVS [ 0.000000] BIOS-e820: [mem 0x00000000cfeba000-0x00000000cfecafff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000cfecb000-0x00000000cfecbfff] ACPI NVS [ 0.000000] BIOS-e820: [mem 0x00000000cfecc000-0x00000000cfedbfff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000cfedc000-0x00000000cfedcfff] ACPI NVS [ 0.000000] BIOS-e820: [mem 0x00000000cfedd000-0x00000000cfeddfff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000cfede000-0x00000000cfee3fff] ACPI NVS [ 0.000000] BIOS-e820: [mem 0x00000000cfee4000-0x00000000cfef6fff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000cfef7000-0x00000000cfefffff] usable [ 0.000000] BIOS-e820: [mem 0x00000000e0000000-0x00000000efffffff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000fec00000-0x00000000fec00fff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000fec10000-0x00000000fec10fff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000fed00000-0x00000000fed00fff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000fed40000-0x00000000fed44fff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000fed61000-0x00000000fed70fff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000fed80000-0x00000000fed8ffff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000ff000000-0x00000000ffffffff] reserved [ 0.000000] BIOS-e820: [mem 0x0000000100001000-0x000000020effffff] usable In this case the area a0000-dffff isn't present in the map. This will confuse the memory setup of the domain when remapping the memory from such holes to populated areas. To avoid the problem the accounting of to be remapped memory has to count such holes in the E820 map as well. Reported-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>		2015-09-08 16:28:04 +01:00
..
apic.c	xen/PMU: Intercept PMU-related MSR and APIC accesses	2015-08-20 12:25:25 +01:00
debugfs.c
debugfs.h
efi.c
enlighten.c	xen/x86: Don't try to set PCE bit in CR4	2015-08-20 12:25:26 +01:00
grant-table.c
irq.c
Kconfig	xen/PMU: Sysfs interface for setting Xen PMU mode	2015-08-20 12:24:26 +01:00
Makefile	xen/PMU: Initialization code for Xen PMU	2015-08-20 12:25:20 +01:00
mmu.c	xen: move p2m list if conflicting with e820 map	2015-08-20 12:24:24 +01:00
mmu.h
multicalls.c
multicalls.h
p2m.c	xen: remove no longer needed p2m.h	2015-08-20 12:24:25 +01:00
pci-swiotlb-xen.c
platform-pci-unplug.c	x86/xen: fix non-ANSI declaration of xen_has_pv_devices()	2015-08-20 12:24:13 +01:00
pmu.c	xen/PMU: PMU emulation code	2015-08-20 12:25:26 +01:00
pmu.h	xen/PMU: Intercept PMU-related MSR and APIC accesses	2015-08-20 12:25:25 +01:00
setup.c	xen: avoid another early crash of memory limited dom0	2015-09-08 16:28:04 +01:00
smp.c	xen/PMU: Initialization code for Xen PMU	2015-08-20 12:25:20 +01:00
smp.h
spinlock.c	locking/pvqspinlock: Rename QUEUED_SPINLOCK to QUEUED_SPINLOCKS	2015-05-11 09:52:09 +02:00
suspend.c	xen/PMU: Initialization code for Xen PMU	2015-08-20 12:25:20 +01:00
time.c
trace.c	xen: use generated hypervisor symbols in arch/x86/xen/trace.c	2015-03-16 14:49:13 +00:00
vdso.h
vga.c
xen-asm_32.S
xen-asm_64.S	x86/asm/entry: Untangle 'system_call' into two entry points: entry_SYSCALL_64 and entry_INT80_32	2015-06-08 09:14:21 +02:00
xen-asm.h
xen-asm.S
xen-head.S	xen: eliminate scalability issues from initial mapping setup	2015-08-20 12:24:18 +01:00
xen-ops.h	xen: move p2m list if conflicting with e820 map	2015-08-20 12:24:24 +01:00