Re: [PATCH for-5.0] xen: fixup RAM memory region initialization

[Anthony PERARD]

On Fri, Mar 27, 2020 at 06:48:28AM -0400, Igor Mammedov wrote:
> Since bd457782b3b0 ("x86/pc: use memdev for RAM") Xen
> machine fails to start with:
>    qemu-system-i386: xen: failed to populate ram at 0
> 
> The reason is that xen_ram_alloc() which is called by
> memory_region_init_ram(), compares memory region with
> statically allocated 'global' ram_memory memory region
> that it uses for RAM, and does nothing in case it matches.
> 
> While it's possible feed machine->ram to xen_ram_alloc()
> in the same manner to keep that hack working, I'd prefer
> not to keep that circular dependency and try to untangle that.
> 
> However it doesn't look trivial to fix, so as temporary
> fixup opt out Xen machine from memdev based RAM allocation,
> and let xen_ram_alloc() do its trick for now.
> 
> Reported-by: Anthony PERARD <address@hidden>
> Signed-off-by: Igor Mammedov <address@hidden>

Reviewed-by: Anthony PERARD <address@hidden>

That should work on most configs. But we also sometime use the "pc"
machine with accel=xen, to run without the "xen-platform" pci device,
but that would be less common.

Thanks,

-- 
Anthony PERARD