Re: [PATCH 1/3] KVM: arm64: vgic: Add Apple M2 cpus to the list of broken SEIS implementations

Nathan Chancellor
2023-01-03T17:59:45Z

Hi Marc,

I have only been lurking on the kvmarm mailing list for a little bit and
it has mainly just been reading patches/review to get more familiar with
various virtualization concepts so I apologize if the following review
is rather shallow but...

On Tue, Jan 03, 2023 at 09:50:20AM +0000, Marc Zyngier wrote:
> I really hoped that Apple had fixed their not-quite-a-vgic implementation
> when moving from M1 to M2. Alas, it seems they didn't, and running
> a buggy EFI version results in the vgic generating SErrors outside
> of the guest and taking the host down.
>
> Apply the same workaround as for M1. Yes, this is all a bit crap.
>
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
> arch/arm64/include/asm/cputype.h | 4 ++++
> arch/arm64/kvm/vgic/vgic-v3.c | 3 ++-
> 2 files changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h
> index 4e8b66c74ea2..683ca3af4084 100644
> --- a/arch/arm64/include/asm/cputype.h
> +++ b/arch/arm64/include/asm/cputype.h
> @@ -124,6 +124,8 @@
> #define APPLE_CPU_PART_M1_FIRESTORM_PRO 0x025
> #define APPLE_CPU_PART_M1_ICESTORM_MAX 0x028
> #define APPLE_CPU_PART_M1_FIRESTORM_MAX 0x029
> +#define APPLE_CPU_PART_M2_BLIZZARD 0x032
> +#define APPLE_CPU_PART_M2_AVALANCHE 0x033
>
> #define AMPERE_CPU_PART_AMPERE1 0xAC3
>
> @@ -177,6 +179,8 @@
> #define MIDR_APPLE_M1_FIRESTORM_PRO MIDR_CPU_MODEL(ARM_CPU_IMP_APPLE, APPLE_CPU_PART_M1_FIRESTORM_PRO)
> #define MIDR_APPLE_M1_ICESTORM_MAX MIDR_CPU_MODEL(ARM_CPU_IMP_APPLE, APPLE_CPU_PART_M1_ICESTORM_MAX)
> #define MIDR_APPLE_M1_FIRESTORM_MAX MIDR_CPU_MODEL(ARM_CPU_IMP_APPLE, APPLE_CPU_PART_M1_FIRESTORM_MAX)
> +#define MIDR_APPLE_M2_BLIZZARD MIDR_CPU_MODEL(ARM_CPU_IMP_APPLE, APPLE_CPU_PART_M2_BLIZZARD)
> +#define MIDR_APPLE_M2_AVALANCHE MIDR_CPU_MODEL(ARM_CPU_IMP_APPLE, APPLE_CPU_PART_M2_AVALANCHE)
> #define MIDR_AMPERE1 MIDR_CPU_MODEL(ARM_CPU_IMP_AMPERE, AMPERE_CPU_PART_AMPERE1)
>
> /* Fujitsu Erratum 010001 affects A64FX 1.0 and 1.1, (v0r0 and v1r0) */
> diff --git a/arch/arm64/kvm/vgic/vgic-v3.c b/arch/arm64/kvm/vgic/vgic-v3.c
> index 826ff6f2a4e7..c6442b08fe80 100644
> --- a/arch/arm64/kvm/vgic/vgic-v3.c
> +++ b/arch/arm64/kvm/vgic/vgic-v3.c
> @@ -615,7 +615,8 @@ static const struct midr_range broken_seis[] = {
> MIDR_ALL_VERSIONS(MIDR_APPLE_M1_ICESTORM_PRO),
> MIDR_ALL_VERSIONS(MIDR_APPLE_M1_FIRESTORM_PRO),
> MIDR_ALL_VERSIONS(MIDR_APPLE_M1_ICESTORM_MAX),
> - MIDR_ALL_VERSIONS(MIDR_APPLE_M1_FIRESTORM_MAX),

The commit message makes no note of this removal, was it intentional?
MIDR_APPLE_M1_FIRESTORM_MAX is only used here so I assume it is not.

> + MIDR_ALL_VERSIONS(MIDR_APPLE_M2_BLIZZARD),
> + MIDR_ALL_VERSIONS(MIDR_APPLE_M2_AVALANCHE),
> {},
> };
>
> --
> 2.34.1
>

Cheers,
Nathan