Messages in this thread | | | Date | Wed, 27 May 2015 17:25:06 +0100 | From | David Vrabel <> | Subject | Re: [Xen-devel] [Patch V3 14/15] xen: allow more than 512 GB of RAM for 64 bit pv-domains |
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On 20/04/15 06:23, Juergen Gross wrote: > 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.
Something in this patch breaks the hvc console in my test domU.
kernel BUG at /local/davidvr/work/k.org/tip/drivers/tty/hvc/hvc_xen.c:153
Which suggests the hvc driver mapped the wrong console ring frame.
David
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