[PATCH] KVM: arm/arm64: vgic: Fix GICC_PMR uaccess on GICv3 and clarify ABI

Marc Zyngier marc.zyngier at arm.com
Wed Mar 22 02:58:36 PDT 2017


On 21/03/17 21:05, Christoffer Dall wrote:
> As an oversight, for GICv2, we accidentally export the GICC_PMR register
> in the format of the GICH_VMCR.VMPriMask field in the lower 5 bits of a
> word, meaning that userspace must always use the lower 5 bits to
> communicate with the KVM device and must shift the value left by 3
> places to obtain the actual priority mask level.
> 
> Since GICv3 supports the full 8 bits of priority masking in the ICH_VMCR,
> we have to fix the value we export when emulating a GICv2 on top of a
> hardware GICv3 and exporting the emulated GICv2 state to userspace.
> 
> Take the chance to clarify this aspect of the ABI.
> 
> Signed-off-by: Christoffer Dall <cdall at linaro.org>

Reviewed-by: Marc Zyngier <marc.zyngier at arm.com>

	M.
-- 
Jazz is not dead. It just smells funny...



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