On 2024-02-19 14:46, Zenghui Yu wrote:
> On 2024/2/19 19:32, Marc Zyngier wrote:
>> For what it is worth, I've just tested both defconfig and my own
>> configuration with both 4k (kvmtool, QEMU+KVM and on SynQuacer) and
>> 16k (kvmtool), without any obvious problem.
>
> I had a quick test on top of next-20240219 with defconfig. I can
> reproduce it with QEMU parameter '-cpu max -accel tcg', but things are
> fine with '-cpu max,lpa2=off -accel tcg'.
>
> Bisection shows that the problem happens when we start putting the
> latest arm64 and kvmarm changes together. The following hack fixes the
> problem for me (but I **only** write it for kernel built with defconfig
> with ARM64_4K_PAGES=y atm).
>
> I can investigate it further tomorrow (as it's too late now ;-) ). Or
> maybe Marc or Catalin can help fix it with a proper approach.
>
> diff --git a/arch/arm64/kernel/cpufeature.c
> b/arch/arm64/kernel/cpufeature.c
> index 4f7662008ede..babdc3f4721b 100644
> --- a/arch/arm64/kernel/cpufeature.c
> +++ b/arch/arm64/kernel/cpufeature.c
> @@ -2798,6 +2798,7 @@ static const struct arm64_cpu_capabilities
> arm64_features[] = {
> | .sign = FTR_SIGNED,
> | .field_pos = ID_AA64MMFR0_EL1_TGRAN4_SHIFT,
> | .min_field_value = ID_AA64MMFR0_EL1_TGRAN4_52_BIT,
> |+ .max_field_value = BIT(ID_AA64MMFR0_EL1_TGRAN4_WIDTH - 1) - 1,
> | #else
> | .sign = FTR_UNSIGNED,
> | .field_pos = ID_AA64MMFR0_EL1_TGRAN16_SHIFT,
Yup, got to that point too.
Working on a slightly more elaborate fix.
Thanks,
M.
--
Jazz is not dead. It just smells funny...