Re: [Xen-devel] [PATCH] xen: arm: remove hardcoded gnttab location from dom0

[Chen Baozi <baozich@xxxxxxxxx>]

On Dec 3, 2013, at 23:04, Ian Campbell <Ian.Campbell@xxxxxxxxxx> wrote:

> The DT provided to guests (including dom0) includes a Xen node which, among
> other things, describes an MMIO region which can be safely used for grant
> table mappings (i.e. it is a hole in the physical address space). For domU we
> provide a hardcoded values based on our hardcoded guest virtual machine
> layout. However for dom0 we need to fit in with the underlying platform.
> Leaving this hardcoded was an oversight which on some platforms could result
> in the grant table overlaying RAM or MMIO regions which are in use by domain
> 0.
> 
> For the 4.4 release do as we did with the dom0 evtchn PPI and provide a hook
> for the platform code to supply a suitable hardcoded address for the platform
> (derived from reading the data sheet). Platforms which do not provide the hook
> get the existing address as a default.
> 
> After 4.4 we should switch to selecting a region of host RAM which is not RAM
> in the guest address map. This should be more flexible and safer but the patch
> was looking too complex for 4.4.
> 
> Platform        Gnttab Address
> ========        ==============
> exynos5.c       0xb0000000, confirmed with Julien.
> sunxi.c         0x01d00000, confirmed in data sheet.
> midway.c        0xff800000, confirmed with Andre, boot tested.
> vexpress.c      0xb0000000, existing hardcoded value was selected for 
> vexpress.
> omap5.c         0xb0000000, no datasheet, looks safe in DTB.
According to OMAP5432 data sheet, 0x80000000~0xbfffffff is the DRAM 
address space. So this is Ok.

Acked-by: Chen Baozi <baozich@xxxxxxxxx>

Cheers,

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