Re: [Xen-devel] [PATCH v2 09/18] mini-os: modify virtual memory layout for support of ballooning

[Samuel Thibault <samuel.thibault@xxxxxxxxxxxx>]

Juergen Gross, on Fri 05 Aug 2016 19:35:53 +0200, wrote:
> In order to be able to support ballooning the virtual memory layout
> of Mini-OS has to be modified: instead of a (nearly) consecutive
> area used for physical memory mapping, on demand mappings, and heap
> we need enough spare place for adding new memory.
> 
> So instead of dynamically place the different regions based on found
> memory size locate them statically at fixed virtual addresses:
> 
> area                           x86-64               x86-32
> ------------------------------------------------------------
> mapped physical memory       00000000             00000000
> kernel virtual mappings    8000000000             3f000000
> demand mappings          100000000000             40000000
> heap                     200000000000             b0000000
> 
> This will enable Mini-OS to support up to 512GB of domain memory with
> a 64 bit kernel and nearly 1GB with a 32 bit kernel.
> 
> For a 32 bit Mini-OS we have to avoid a conflict between heap and
> m2p table which the hypervisor maps at f5600000. So the demand mapping
> size is reduced by 256MB in order to keep the heap at about 1GB.
> 
> The kernel virtual mappings are a new area needed for being able to
> grow the p2m list without having to relocate it in physical memory.
> 
> Modify the placement of the demand mappings and heap and adjust the
> memory layout description.
> 
> Signed-off-by: Juergen Gross <jgross@xxxxxxxx>

Reviewed-by: Samuel Thibault <samuel.thibault@xxxxxxxxxxxx>

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
https://lists.xen.org/xen-devel