[PATCH 0/4] KVM: arm64: A510 errata workaround and fixes for fixup_guest_exit()

[James Morse]

Hello!

Early Cortex-A510 parts have a nasty erratum where two ERETs,
pointer-auth and software step conspire to corrupt SPSR_EL2. A
guest can only trigger this when it is being stepped by EL2, which
gives EL2 the opportunity to work around the erratum. Patch 4 does
this, the SDEN is available from:
https://developer.arm.com/documentation/SDEN2397239/900

Patches 2 and 3 fix two issues with the adjacent code where a stale
esr value could be used to alter the ELR_EL2 when an IRQ synchronises
an SError, and when an HVC synchronises an SError, the HVC may be
handled twice, (not just execute twice).


There are three series that would add the Cortex-A510 part macros. I've picked
Anshuman's patch that does this, on the assumption that makes someone's life
easier. I haven't spotted that patch on the arm64/for-next/fixes branch, so
I've not included the hash in the prerequisite field of the CC-stable.

Let me know if you want this reposted once that value is known.

This series is based on v5.17-rc1 and can be retrieved from:
https://git.gitlab.arm.com/linux-arm/linux-jm.git a510_errata/kvm_bits/v1


Thanks,

James

Anshuman Khandual (1):
  arm64: Add Cortex-A510 CPU part definition

James Morse (3):
  KVM: arm64: Avoid consuming a stale esr value when SError occur
  KVM: arm64: Stop handle_exit() from handling HVC twice when an SError
    occurs
  KVM: arm64: Workaround Cortex-A510's single-step and PAC trap errata

 Documentation/arm64/silicon-errata.rst  |  2 ++
 arch/arm64/Kconfig                      | 16 +++++++++++++++
 arch/arm64/include/asm/cputype.h        |  2 ++
 arch/arm64/kernel/cpu_errata.c          |  8 ++++++++
 arch/arm64/kvm/handle_exit.c            |  8 ++++++++
 arch/arm64/kvm/hyp/include/hyp/switch.h | 27 +++++++++++++++++++++----
 arch/arm64/tools/cpucaps                |  1 +
 7 files changed, 60 insertions(+), 4 deletions(-)

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2.30.2