From 0de58f852875a0f0dcfb120bb8433e4e73c7803b Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Thu, 3 Dec 2015 09:25:22 +0100 Subject: [PATCH] ARM/arm64: KVM: correct PTE uncachedness check Commit e6fab5442345 ("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: e6fab5442345 ("ARM/arm64: KVM: test properly for a PTE's uncachedness") Cc: stable@vger.kernel.org Tested-by: Pavel Fedin Signed-off-by: Ard Biesheuvel Signed-off-by: Marc Zyngier --- arch/arm/kvm/mmu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c index 7dace909d5cf..61d96a645ff3 100644 --- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -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); } -- 2.20.1