Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752825AbaDCP0T (ORCPT ); Thu, 3 Apr 2014 11:26:19 -0400 Received: from fw-tnat.austin.arm.com ([217.140.110.23]:47481 "EHLO collaborate-mta1.arm.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752489AbaDCP0P (ORCPT ); Thu, 3 Apr 2014 11:26:15 -0400 Message-ID: <533D7D8B.2030806@arm.com> Date: Thu, 03 Apr 2014 16:26:03 +0100 From: Marc Zyngier User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130330 Thunderbird/17.0.5 MIME-Version: 1.0 To: Eric Auger CC: "eric.auger@st.com" , "christoffer.dall@linaro.org" , "linux-arm-kernel@lists.infradead.org" , "kvmarm@lists.cs.columbia.edu" , "kvm@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "patches@linaro.org" , "christophe.barnichon@st.com" Subject: Re: [PATCH] ARM: KVM: Handle IPA unmapping on memory region deletion References: <1396538266-13245-1-git-send-email-eric.auger@linaro.org> In-Reply-To: <1396538266-13245-1-git-send-email-eric.auger@linaro.org> X-Enigmail-Version: 1.4.6 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Eric, On 03/04/14 16:17, Eric Auger wrote: > Currently when a KVM region is removed using > kvm_vm_ioctl_set_memory_region (with memory region size equal to 0), the > corresponding intermediate physical memory is not unmapped. > > This patch unmaps the region's IPA range in > kvm_arch_commit_memory_region using unmap_stage2_range. > > The patch was tested on QEMU VFIO based use case where RAM memory region > creation/deletion frequently happens for IRQ handling. > > Notes: > - the KVM_MR_MOVE case shall request some similar addition but I cannot test > this currently I think you should try to handle it anyway. I'm sure you could hack QEMU to do this test it, but even if you don't, better plug that hole right now. > Signed-off-by: Eric Auger > --- > arch/arm/include/asm/kvm_mmu.h | 2 ++ > arch/arm/kvm/arm.c | 8 ++++++++ > arch/arm/kvm/mmu.c | 2 +- > 3 files changed, 11 insertions(+), 1 deletion(-) > > diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h > index 2d122ad..a91c863 100644 > --- a/arch/arm/include/asm/kvm_mmu.h > +++ b/arch/arm/include/asm/kvm_mmu.h > @@ -52,6 +52,8 @@ void kvm_free_stage2_pgd(struct kvm *kvm); > int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa, > phys_addr_t pa, unsigned long size); > > +void unmap_stage2_range(struct kvm *kvm, phys_addr_t guest_ipa, u64 size); > + > int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run); > > void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu); > diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c > index bd18bb8..9a4bc10 100644 > --- a/arch/arm/kvm/arm.c > +++ b/arch/arm/kvm/arm.c > @@ -241,6 +241,14 @@ void kvm_arch_commit_memory_region(struct kvm *kvm, > const struct kvm_memory_slot *old, > enum kvm_mr_change change) > { > + if (change == KVM_MR_DELETE) { > + gpa_t gpa = old->base_gfn << PAGE_SHIFT; > + u64 size = old->npages << PAGE_SHIFT; > + > + spin_lock(&kvm->mmu_lock); > + unmap_stage2_range(kvm, gpa, size); > + spin_unlock(&kvm->mmu_lock); > + } > } Just move the whole function to mmu.c, as it makes more sense to have it there. And while you're at it, how about moving the other memslot/memory_region stubs? > void kvm_arch_flush_shadow_all(struct kvm *kvm) > diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c > index 7789857..e8580e2 100644 > --- a/arch/arm/kvm/mmu.c > +++ b/arch/arm/kvm/mmu.c > @@ -443,7 +443,7 @@ int kvm_alloc_stage2_pgd(struct kvm *kvm) > * destroying the VM), otherwise another faulting VCPU may come in and mess > * with things behind our backs. > */ > -static void unmap_stage2_range(struct kvm *kvm, phys_addr_t start, u64 size) > +void unmap_stage2_range(struct kvm *kvm, phys_addr_t start, u64 size) > { > unmap_range(kvm, kvm->arch.pgd, start, size); > } > Looks sensible otherwise. Thanks! M. -- Jazz is not dead. It just smells funny... -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/