Re: [PATCH v4 1/4] xen/arm: vgic-v2: Report the correct GICC size to the guest

[Ian Campbell <ian.campbell@citrix.com>]

On Thu, 2015-10-08 at 19:23 +0100, Julien Grall wrote:
> The GICv2 DT node is usually used by the guest to know the address/size
> of the regions (GICD, GICC...) to map into their virtual memory.
> 
> While the GICv2 spec requires the size of the GICC to be 8KB, we
> correctly do an 8KB stage-2 mapping but errornously report 256 in the
> device tree (based on GUEST_GICC_SIZE).

"erroneously"

> 
> I bet we didn't see any issue so far because all the registers except
> GICC_DIR lives in the first 256 bytes of the GICC region and all the guest

"guests"

> I have seen so far are driving the GIC with GICC_CTLR.EIOmode =
> 0.
> 
> Signed-off-by: Julien Grall <julien.grall@citrix.com>

Acked-by: Ian Campbell <ian.campbell@citrix.com>

(typo's fixable on commit).

> ---
>     This patch is a good candidate to backport for Xen 4.6 - 4.4.
>     Without it a guest relying on the DT can't use GICC_DIR.

Noted, but just to check: This patch (and none of the other fixes in this
series) are all which are required for a guest to be able to use GICC_DIR,
right?