Re: [PATCH v2 for 6.2?] gicv3: fix ICH_MISR's LRENP computation

[Peter Maydell]

On Tue, 7 Dec 2021 at 09:44, Damien Hedde <damien.hedde@greensocs.com> wrote:
>
> According to the "Arm Generic Interrupt Controller Architecture
> Specification GIC architecture version 3 and 4" (version G: page 345
> for aarch64 or 509 for aarch32):
> LRENP bit of ICH_MISR is set when ICH_HCR.LRENPIE==1 and
> ICH_HCR.EOIcount is non-zero.
>
> When only LRENPIE was set (and EOI count was zero), the LRENP bit was
> wrongly set and MISR value was wrong.
>
> As an additional consequence, if an hypervisor set ICH_HCR.LRENPIE,
> the maintenance interrupt was constantly fired. It happens since patch
> 9cee1efe92 ("hw/intc: Set GIC maintenance interrupt level to only 0 or 1")
> which fixed another bug about maintenance interrupt (most significant
> bits of misr, including this one, were ignored in the interrupt trigger).
>
> Fixes: 83f036fe3d ("hw/intc/arm_gicv3: Add accessors for ICH_ system 
> registers")
> Signed-off-by: Damien Hedde <damien.hedde@greensocs.com>
> ---
> The gic doc is available here:
> https://developer.arm.com/documentation/ihi0069/g
>
> v2: identical resend because subject screw-up (sorry)

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

I won't try to put this into 6.2 unless you have a common guest
that runs into this bug.

thanks
-- PMM