Please backport the following v6.7 commit:

commit be097997a273 ("KVM: arm64: Always invalidate TLB for stage-2 permission faults")

to stable kernels v5.15 and newer to fix:

It is possible for multiple vCPUs to fault on the same IPA and attempt to resolve the fault. One of the page table walks will actually update the PTE and the rest will return -EAGAIN per our race detection scheme. KVM elides the TLB invalidation on the racing threads as the return value is nonzero.

Before commit a12ab1378a88 ("KVM: arm64: Use local TLBI on permission relaxation") KVM always used broadcast TLB invalidations when handling permission faults, which had the convenient property of making the stage-2 updates visible to all CPUs in the system. However now we do a local invalidation, and TLBI elision leads to the vCPU thread faulting again on the stale entry. Remember that the architecture permits the TLB to cache translations that precipitate a permission fault.

Invalidate the TLB entry responsible for the permission fault if the stage-2 descriptor has been relaxed, regardless of which thread actually did the job.

Thank you! doug rady