ARM/arm64: KVM: correct PTE uncachedness check

Commit e6fab54423 ("ARM/arm64: KVM: test properly for a PTE's
uncachedness") modified the logic to test whether a HYP or stage-2
mapping needs flushing, from [incorrectly] interpreting the page table
attributes to [incorrectly] checking whether the PFN that backs the
mapping is covered by host system RAM. The PFN number is part of the
output of the translation, not the input, so we have to use pte_pfn()
on the contents of the PTE, not __phys_to_pfn() on the HYP virtual
address or stage-2 intermediate physical address.

Fixes: e6fab54423 ("ARM/arm64: KVM: test properly for a PTE's uncachedness")
Cc: stable@vger.kernel.org
Tested-by: Pavel Fedin <p.fedin@samsung.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
This commit is contained in:
Ard Biesheuvel 2015-12-03 09:25:22 +01:00 committed by Marc Zyngier
parent f6be563abb
commit 0de58f8528

View file

@ -218,7 +218,7 @@ static void unmap_ptes(struct kvm *kvm, pmd_t *pmd,
kvm_tlb_flush_vmid_ipa(kvm, addr);
/* No need to invalidate the cache for device mappings */
if (!kvm_is_device_pfn(__phys_to_pfn(addr)))
if (!kvm_is_device_pfn(pte_pfn(old_pte)))
kvm_flush_dcache_pte(old_pte);
put_page(virt_to_page(pte));
@ -310,7 +310,7 @@ static void stage2_flush_ptes(struct kvm *kvm, pmd_t *pmd,
pte = pte_offset_kernel(pmd, addr);
do {
if (!pte_none(*pte) && !kvm_is_device_pfn(__phys_to_pfn(addr)))
if (!pte_none(*pte) && !kvm_is_device_pfn(pte_pfn(*pte)))
kvm_flush_dcache_pte(*pte);
} while (pte++, addr += PAGE_SIZE, addr != end);
}