linux_dsm_epyc7002/arch/x86/xen
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: 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
efi.c xen/efi: Directly include needed headers 2014-09-23 13:36:20 +00:00
enlighten.c xen/x86: Don't try to set PCE bit in CR4 2015-08-20 12:25:26 +01:00
grant-table.c x86/xen: use vmap() to map grant table pages in PVH guests 2014-08-11 11:59:35 +01:00
irq.c asmlinkage, x86: Add explicit __visible to arch/x86/* 2014-05-05 16:07:44 -07:00
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 xen: make a pile of mmu pvop functions static 2011-05-20 14:25:24 -07:00
multicalls.c x86: Replace __get_cpu_var uses 2014-08-26 13:45:49 -04:00
multicalls.h xen: use this_cpu_xxx replace percpu_xxx funcs 2012-01-24 12:20:24 -05:00
p2m.c xen: remove no longer needed p2m.h 2015-08-20 12:24:25 +01:00
pci-swiotlb-xen.c pci-swiotlb-xen: call pci_request_acs only ifdef CONFIG_PCI 2013-11-08 15:21:44 -05:00
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 x86/xen: Set EFER.NX and EFER.SCE in PVH guests 2014-10-06 10:27:47 +01:00
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 x86/xen: prefer TSC over xen clocksource for dom0 2015-01-20 18:44:24 +00:00
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/vga: add the xen EFI video mode support 2012-09-24 09:28:57 -04:00
xen-asm_32.S x86/xen: Fix 32-bit PV guests's usage of kernel_stack 2014-04-15 15:00:14 +01:00
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: 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: 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