Re: [PATCH v2] hw/intc/arm_gicv3_cpuif: Tolerate spurious EOIR writes

[Philippe Mathieu-Daudé]

On 6/4/21 3:03 PM, Jean-Philippe Brucker wrote:
> Commit 382c7160d1cd ("hw/intc/arm_gicv3_cpuif: Fix EOIR write access
> check logic") added an assert_not_reached() if the guest writes the EOIR
> register while no interrupt is active.
> 
> It turns out some software does this: EDK2, in
> GicV3ExitBootServicesEvent(), unconditionally write EOIR for all
> interrupts that it manages. This now causes QEMU to abort when running
> UEFI on a VM with GICv3. Although it is UNPREDICTABLE behavior and EDK2
> does need fixing, the punishment seems a little harsh, especially since
> icc_eoir_write() already tolerates writes of nonexistent interrupt
> numbers. Display a guest error and tolerate spurious EOIR writes.
> 
> Fixes: 382c7160d1cd ("hw/intc/arm_gicv3_cpuif: Fix EOIR write access check 
> logic")
> Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
> ---
> v2: Added qemu_log_mask() (so I didn't keep the Reviewed-by tag)
> v1: 
> 20210603110012.1182530-1-jean-philippe@linaro.org/">https://lore.kernel.org/qemu-devel/20210603110012.1182530-1-jean-philippe@linaro.org/
> 
> ---
>  hw/intc/arm_gicv3_cpuif.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>