Re: [PATCH] KVM: arm64: Add an ISB after mapping a hyp fixmap slot

[Marc Zyngier]

On Wed, 28 Oct 2026 23:02:10 +0000, Xuheng Li wrote:
> fixmap_map_slot() installs a valid PTE for the CPU's fixmap slot (or
> the fixblock slot) and issues a DSB ISHST before returning the slot's
> VA, which the caller then accesses.  It does not issue an ISB.
> 
> The DSB guarantees that the PTE write has completed, but without a
> context synchronization event the architecture does not guarantee that
> a later access on the same CPU uses the new entry: its translation may
> have been performed speculatively while the slot was still invalid, in
> which case the access takes a translation fault.  At EL2 that fault
> ends in hyp_panic().  The clear side, fixmap_clear_slot(), already ends
> with an ISB.
> 
> [...]

Applied to fixes, thanks!

[1/1] KVM: arm64: Add an ISB after mapping a hyp fixmap slot
      commit: 0e24f9db2ebedc271add0c5dbf2821b8f8a0ab06

Cheers,

	M.
-- 
Without deviation from the norm, progress is not possible.