boot-qemu.sh: Use different CPU for arm64 with new QEMU + old kernel#61
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nathanchance merged 1 commit intoApr 6, 2022
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nathanchance
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From that thread, it sounds like there's perhaps a missing backport we should take into stable instead? |
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Maybe, I'll see. |
After FEAT_LPA was implemented in QEMU's TCG, kernels without
commit 787fd1d019b2 ("arm64: limit PA size to supported range") fail to
boot; this change first showed up in 4.16.
We already have a workaround for FEAT_LPA2 not working with kernels
older than 5.12, which is known. Reporting this to QEMU upstream
resulted in the recommendation to use one of the ARMv8.0 CPUs for these
older kernels. Use 'cortex-a72' for booting anything older than 4.16
with QEMU 6.2.50 (master) and newer.
Link: https://gitlab.com/qemu-project/qemu/-/issues/964
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
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I've updated the kernel check and commit message based on my analysis at https://gitlab.com/qemu-project/qemu/-/issues/964#note_903403849. |
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thanks for running the bisection to identify the change, the asses the risks in backporting it. Looks like this is the way to go. 🆔 ⛲
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Thanks for double checking my analysis as always! |
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After FEAT_LPA was implemented in QEMU's TCG, kernels older than 4.19,
namely 4.9 and 4.14, fail to boot. We already have a workaround for
FEAT_LPA2 not working with kernels older than 5.12, which is known.
Reporting this to QEMU upstream resulted in the recommendation to use
one of the ARMv8.0 CPUs for these older kernels. Use 'cortex-a72' for
booting anything older than 4.19 with QEMU 6.2.50 (master) and newer.
Link: https://gitlab.com/qemu-project/qemu/-/issues/964