[PATCH 0/3] KVM: arm64: Handle CCSIDR associativity mismatches

Akihiko Odaki akihiko.odaki at daynix.com
Thu Dec 1 02:49:11 PST 2022


M2 MacBook Air has mismatched CCSIDR associativity bits, which makes the
bits a KVM vCPU sees inconsistent when migrating.

It also makes QEMU fail restoring the vCPU registers because QEMU saves
and restores all of the registers including CCSIDRs, and if the vCPU
migrated among physical CPUs between saving and restoring, it tries to
restore CCSIDR values that mismatch with the current physical CPU, which
causes EFAULT.

Trap CCSIDRs if there are CCSIDR value msimatches, and override the
associativity bits when handling the trap.

Akihiko Odaki (3):
  KVM: arm64: Make CCSIDRs consistent
  arm64: errata: Check for mismatched cache associativity
  KVM: arm64: Handle CCSIDR associativity mismatches

 arch/arm64/include/asm/cache.h       |  3 ++
 arch/arm64/include/asm/cpu.h         |  1 +
 arch/arm64/include/asm/cpufeature.h  |  8 +++++
 arch/arm64/include/asm/kvm_emulate.h | 10 ++++--
 arch/arm64/include/asm/sysreg.h      |  7 ++++
 arch/arm64/kernel/cacheinfo.c        |  4 +--
 arch/arm64/kernel/cpu_errata.c       | 52 ++++++++++++++++++++++++++++
 arch/arm64/kernel/cpufeature.c       |  4 +++
 arch/arm64/kernel/cpuinfo.c          | 30 ++++++++++++++++
 arch/arm64/kvm/sys_regs.c            | 50 ++++++++++++++------------
 arch/arm64/tools/cpucaps             |  1 +
 11 files changed, 144 insertions(+), 26 deletions(-)

-- 
2.38.1




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