Commit 8442d653 authored by Marc Zyngier's avatar Marc Zyngier
Browse files

KVM: arm64: pkvm: Document the side effects of kvm_flush_dcache_to_poc() 



We rely on the presence of a DSB at the end of kvm_flush_dcache_to_poc()
that, on top of ensuring completion of the cache clean, also covers
the speculative page table walk started from EL1.

Document this dependency.

Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Reviewed-by: default avatarOliver Upton <oliver.upton@linux.dev>
parent 7e1b2329

arch/arm64/kvm/hyp/nvhe/mem_protect.c

+7 −0
Original line number Diff line number Diff line
@@ -297,6 +297,13 @@ int __pkvm_prot_finalize(void) 
	params->vttbr = kvm_get_vttbr(mmu);

	params->vtcr = host_mmu.arch.vtcr;

	params->hcr_el2 |= HCR_VM;



	/*

	 * The CMO below not only cleans the updated params to the

	 * PoC, but also provides the DSB that ensures ongoing

	 * page-table walks that have started before we trapped to EL2

	 * have completed.

	 */

	kvm_flush_dcache_to_poc(params, sizeof(*params));



	write_sysreg(params->hcr_el2, hcr_el2);