From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Fedin Subject: [PATCH] KVM: arm/arm64: Revert to old way of checking for device mapping in stage2_flush_ptes(). Date: Tue, 01 Dec 2015 16:03:52 +0300 Message-ID: <1448975032-7156-1-git-send-email-p.fedin@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: marc.zyngier@arm.com, stable@vger.kernel.org, Ard Biesheuvel To: kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Return-path: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu List-Id: kvm.vger.kernel.org This function takes stage-II physical addresses (A.K.A. IPA), on input, not real physical addresses. This causes kvm_is_device_pfn() to return wrong values, depending on how much guest and host memory maps match. This results in completely broken KVM on some boards. The problem has been caught on Samsung proprietary hardware. Cc: stable@vger.kernel.org Fixes: e6fab5442345 ("ARM/arm64: KVM: test properly for a PTE's uncachedness") Signed-off-by: Pavel Fedin --- arch/arm/kvm/mmu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c index 7dace90..51ad98f 100644 --- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -310,7 +310,8 @@ 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) && + (pte_val(*pte) & PAGE_S2_DEVICE) != PAGE_S2_DEVICE) kvm_flush_dcache_pte(*pte); } while (pte++, addr += PAGE_SIZE, addr != end); } -- 2.4.4