diff options
| author |   Juergen Gross <jgross@suse.com> | 2015-07-17 06:51:36 +0200 |
|---|---|---|
| committer |   David Vrabel <david.vrabel@citrix.com> | 2015-08-20 12:24:24 +0100 |
| commit | c70727a5bc18a5a233fddc6056d1de9144d7a293 (patch) | |
| tree | 98c09e90e78f0d3bb79be2592e3bed5e5c847f83 /arch/x86/xen/Kconfig | |
| parent | xen: move p2m list if conflicting with e820 map (diff) | |
| download | wireguard-linux-c70727a5bc18a5a233fddc6056d1de9144d7a293.tar.xz wireguard-linux-c70727a5bc18a5a233fddc6056d1de9144d7a293.zip | |
xen: allow more than 512 GB of RAM for 64 bit pv-domains
64 bit pv-domains under Xen are limited to 512 GB of RAM today. The
main reason has been the 3 level p2m tree, which was replaced by the
virtual mapped linear p2m list. Parallel to the p2m list which is
being used by the kernel itself there is a 3 level mfn tree for usage
by the Xen tools and eventually for crash dump analysis. For this tree
the linear p2m list can serve as a replacement, too. As the kernel
can't know whether the tools are capable of dealing with the p2m list
instead of the mfn tree, the limit of 512 GB can't be dropped in all
cases.
This patch replaces the hard limit by a kernel parameter which tells
the kernel to obey the 512 GB limit or not. The default is selected by
a configuration parameter which specifies whether the 512 GB limit
should be active per default for domUs (domain save/restore/migration
and crash dump analysis are affected).
Memory above the domain limit is returned to the hypervisor instead of
being identity mapped, which was wrong anyway.
The kernel configuration parameter to specify the maximum size of a
domain can be deleted, as it is not relevant any more.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Diffstat (limited to 'arch/x86/xen/Kconfig')
| -rw-r--r-- | arch/x86/xen/Kconfig | 20 |
1 files changed, 12 insertions, 8 deletions
diff --git a/arch/x86/xen/Kconfig b/arch/x86/xen/Kconfig index e88fda867a33..7bcf21b865d1 100644 --- a/arch/x86/xen/Kconfig +++ b/arch/x86/xen/Kconfig @@ -23,14 +23,18 @@ config XEN_PVHVM def_bool y depends on XEN && PCI && X86_LOCAL_APIC -config XEN_MAX_DOMAIN_MEMORY - int - default 500 if X86_64 - default 64 if X86_32 - depends on XEN - help - This only affects the sizing of some bss arrays, the unused - portions of which are freed. +config XEN_512GB + bool "Limit Xen pv-domain memory to 512GB" + depends on XEN && X86_64 + default y + help + Limit paravirtualized user domains to 512GB of RAM. + + The Xen tools and crash dump analysis tools might not support + pv-domains with more than 512 GB of RAM. This option controls the + default setting of the kernel to use only up to 512 GB or more. + It is always possible to change the default via specifying the + boot parameter "xen_512gb_limit". config XEN_SAVE_RESTORE bool |