From a9c0e12ebee56ef06b7eccdbc73bab71d0018df8 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Mon, 23 Oct 2017 17:11:20 +0100 Subject: [PATCH] KVM: arm/arm64: Only clean the dcache on translation fault The only case where we actually need to perform a dcache maintenance is when we map the page for the first time, and subsequent permission faults do not require cache maintenance. Let's make it conditional on not being a permission fault (and thus a translation fault). Reviewed-by: Christoffer Dall Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall --- virt/kvm/arm/mmu.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c index 0417c8e2a81c..f956efbd933d 100644 --- a/virt/kvm/arm/mmu.c +++ b/virt/kvm/arm/mmu.c @@ -1400,7 +1400,9 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, new_pmd = kvm_s2pmd_mkwrite(new_pmd); kvm_set_pfn_dirty(pfn); } - clean_dcache_guest_page(vcpu, pfn, PMD_SIZE); + + if (fault_status != FSC_PERM) + clean_dcache_guest_page(vcpu, pfn, PMD_SIZE); if (exec_fault) { new_pmd = kvm_s2pmd_mkexec(new_pmd); @@ -1416,7 +1418,9 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, kvm_set_pfn_dirty(pfn); mark_page_dirty(kvm, gfn); } - clean_dcache_guest_page(vcpu, pfn, PAGE_SIZE); + + if (fault_status != FSC_PERM) + clean_dcache_guest_page(vcpu, pfn, PAGE_SIZE); if (exec_fault) { new_pte = kvm_s2pte_mkexec(new_pte);