Re: [RFC PATCH v8 09/10] vmapple, gicv2m: add macOS compat quirk

[Mohamed Mediouni]

> On 16. Sep 2026, at 12:51, Peter Maydell <peter.mayd...@linaro.org> wrote:
> 
> On Wed, 16 Sept 2026 at 11:00, Mohamed Mediouni
> <moha...@unpredictable.fr> wrote:
>> 
>> macOS expects bit 31 of MSI_TYPER to be set.
>> 
>> Signed-off-by: Mohamed Mediouni <moha...@unpredictable.fr>
>> ---
> 
> This is a macos bug -- the Arm Base System Architecture
> spec which defines what the GICv2M registers are is clear
> that MSI_TYPER bits [31:26] are RES0. I'm not keen on working
> around guest bugs here, especially of the "random proprietary
> guest has mysterious undocumented requirement" kind: insisting
> on bit 31 being set would presumably break on a real hardware
> GICv2M as well.
> 
> If there's some documented "Apple GICv2m" variant of this
> hardware, then we could potentially model it, but I'd
> rather do that as a "here's the spec we're modelling,
> implement it" than a one-off point hack.
> 
> — PMM

Hi,

vmapple as a whole is a reverse-engineered target without a public 
specification of any kind…

other than this patch the system is happy, but without it, there’s a kernel 
panic really
early on during boot…

There are no specific Apple GICv2m registers.