Re: [PATCH v2 4/5] arm64: Use __tlbi_dsb() macros in KVM code

From: Mark Rutland
Date: Tue Jan 03 2017 - 11:01:29 EST


On Thu, Dec 29, 2016 at 05:43:34PM -0500, Christopher Covington wrote:
> Refactor the KVM code to use the newly introduced __tlbi_dsb macros, which
> will allow an errata workaround that repeats tlbi dsb sequences to only
> change one location. This is not intended to change the generated assembly
> and comparing before and after vmlinux objdump shows no functional changes.

> @@ -40,9 +41,7 @@ void __hyp_text __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)
> * complete (S1 + S2) walk based on the old Stage-2 mapping if
> * the Stage-1 invalidation happened first.
> */
> - dsb(ish);

Looks like this got accidentally removed. AFAICT it is still necessary.

> - asm volatile("tlbi vmalle1is" : : );
> - dsb(ish);
> + __tlbi_dsb(vmalle1is, ish);
> isb();

Thanks,
Mark.