On Wed, Jul 22, 2015 at 04:44:14PM +0100, Ian Jackson wrote:
> From: Tiejun Chen <tiejun.c...@intel.com>
>
> While building a VM, HVM domain builder provides struct hvm_info_table{}
> to help hvmloader. Currently it includes two fields to construct guest
> e820 table by hvmloader, low_mem_pgend and high_mem_pgend. So we should
> check them to fix any conflict with RDM.
>
> RMRR can reside in address space beyond 4G theoretically, but we never
> see this in real world. So in order to avoid breaking highmem layout
> we don't solve highmem conflict. Note this means highmem rmrr could still
> be supported if no conflict.
>
> But in the case of lowmem, RMRR probably scatter the whole RAM space.
> Especially multiple RMRR entries would worsen this to lead a complicated
> memory layout. And then its hard to extend hvm_info_table{} to work
> hvmloader out. So here we're trying to figure out a simple solution to
> avoid breaking existing layout. So when a conflict occurs,
>
> #1. Above a predefined boundary (2G)
> - move lowmem_end below reserved region to solve conflict;
>
> #2. Below a predefined boundary (2G)
> - Check strict/relaxed policy.
> "strict" policy leads to fail libxl. Note when both policies
> are specified on a given region, 'strict' is always preferred.
> "relaxed" policy issue a warning message and also mask this entry
> INVALID
> to indicate we shouldn't expose this entry to hvmloader.
>
> Note later we need to provide a parameter to set that predefined boundary
> dynamically.
>
> CC: Ian Jackson <ian.jack...@eu.citrix.com>
> CC: Stefano Stabellini <stefano.stabell...@eu.citrix.com>
> CC: Ian Campbell <ian.campb...@citrix.com>
> CC: Wei Liu <wei.l...@citrix.com>
> Signed-off-by: Tiejun Chen <tiejun.c...@intel.com>
> Reviewed-by: Kevin Tian <kevin.t...@intel.com>
Ian, you forgot your S-o-B.
Acked-by: Wei Liu <wei.l...@citrix.com>
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