Messages in this thread | | | Subject | Re: [PATCH V2] arm64/mm: Fix __enable_mmu() for new TGRAN range values | From | Zenghui Yu <> | Date | Fri, 28 Oct 2022 10:18:41 +0800 |
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On 2022/8/26 20:00, Anders Roxell wrote: > On 2021-03-10 11:23, Anshuman Khandual wrote: >> From: James Morse <james.morse@arm.com> >> >> As per ARM ARM DDI 0487G.a, when FEAT_LPA2 is implemented, ID_AA64MMFR0_EL1 >> might contain a range of values to describe supported translation granules >> (4K and 16K pages sizes in particular) instead of just enabled or disabled >> values. This changes __enable_mmu() function to handle complete acceptable >> range of values (depending on whether the field is signed or unsigned) now >> represented with ID_AA64MMFR0_TGRAN_SUPPORTED_[MIN..MAX] pair. While here, >> also fix similar situations in EFI stub and KVM as well. >> >> Cc: Catalin Marinas <catalin.marinas@arm.com> >> Cc: Will Deacon <will@kernel.org> >> Cc: Marc Zyngier <maz@kernel.org> >> Cc: James Morse <james.morse@arm.com> >> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> >> Cc: Ard Biesheuvel <ardb@kernel.org> >> Cc: Mark Rutland <mark.rutland@arm.com> >> Cc: linux-arm-kernel@lists.infradead.org >> Cc: kvmarm@lists.cs.columbia.edu >> Cc: linux-efi@vger.kernel.org >> Cc: linux-kernel@vger.kernel.org >> Acked-by: Marc Zyngier <maz@kernel.org> >> Signed-off-by: James Morse <james.morse@arm.com> >> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> > > Hi, > > When building an arm64 defconfig kernel from stable/linux-5.10.y and > booting that in QEMU (version: 1:7.0+dfsg-2~bpo11+2) with '-cpu max' the > kernel doesn't boot. I don't get any output. The kernel boots fine if I > change to '-cpu cortex-a72'. > > If I cherry-pick this patch to stable/linux-5.10.y I'm able too boot the > kernel with '-cpu max'.
You can workaround the kernel boot failure by specifying '-cpu max,lpa2=off' [*] in the QEMU command line.
> However, I'm not comfortable to backport this patch to older kernels > since there are a lot of conflicts. > Can someone help out to do the packport?
Upstream commit 26f55386f964 ("arm64/mm: Fix __enable_mmu() for new TGRAN range values") can still be applied cleanly on top of linux-5.10.y. I can send it to <stable@vger.kernel.org> if maintainers are okay with the stable-5.10 backport.
[*] https://gitlab.com/qemu-project/qemu/-/commit/69b2265d5fe8
Zenghui
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