Re: [PATCH] stubdom: foreignmemory: Fix build after 0dbb4be739c5

[Juergen Gross]

On 13.07.21 16:38, Julien Grall wrote:

Hi Juergen,

On 13/07/2021 15:23, Juergen Gross wrote:

On 13.07.21 16:19, Julien Grall wrote:

Hi Jan,

On 13/07/2021 15:14, Jan Beulich wrote:

And I don't think it should be named XC_PAGE_*, but rather XEN_PAGE_*.

runtime query to the hypervisor would be needed instead.

Even that doesn't seem right to me, at least in principle. There shouldn't be a build time setting when it may vary at runtime. IOW on Arm I think a

Yes, we want to be able to use the same userspace/OS without rebuilding to a specific hypervisor page size.

This define is used for accessing data of other domains. See the define
for XEN_PAGE_SIZE in xen/include/public/io/ring.h

So it should be a constant (minimal) page size for all hypervisors and
guests of an architecture.

Do you mean the maximum rather than minimal? If you use the minimal (4KB), then you would not be able to map the page in the stage-2 if the hypervisor is using 64KB.

But this would mean that the current solution to use XC_PAGE_SIZE is
wrong, as this is 4k.


Juergen

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