Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752924AbaDCQc0 (ORCPT ); Thu, 3 Apr 2014 12:32:26 -0400 Received: from mail-we0-f175.google.com ([74.125.82.175]:39518 "EHLO mail-we0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752702AbaDCQcU (ORCPT ); Thu, 3 Apr 2014 12:32:20 -0400 Message-ID: <533D8D10.7070909@linaro.org> Date: Thu, 03 Apr 2014 18:32:16 +0200 From: Eric Auger User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: Marc Zyngier 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> <533D7D8B.2030806@arm.com> In-Reply-To: <533D7D8B.2030806@arm.com> 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 On 04/03/2014 05:26 PM, Marc Zyngier wrote: > 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. Hi Marc, OK I will proceed > >> 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? OK I will move: kvm_arch_free_memslot, kvm_arch_create_memslot, kvm_arch_prepare_memory_region, kvm_arch_commit_memory_region, kvm_arch_shadow_all and kvm_arch_shadow_memslot then. Best Regards Eric > >> 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. > -- 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/