Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757837AbbGGPWN (ORCPT ); Tue, 7 Jul 2015 11:22:13 -0400 Received: from mx1.redhat.com ([209.132.183.28]:39937 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751514AbbGGPWH (ORCPT ); Tue, 7 Jul 2015 11:22:07 -0400 Message-ID: <1436282525.1391.42.camel@redhat.com> Subject: Re: [PATCH 1/4] KVM: count number of assigned devices From: Alex Williamson To: Paolo Bonzini Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, guangrong.xiao@linux.intel.com, jroedel@suse.de, ogerlitz@mellanox.com, amirv@mellanox.com Date: Tue, 07 Jul 2015 09:22:05 -0600 In-Reply-To: <1436276739-50326-2-git-send-email-pbonzini@redhat.com> References: <1436276739-50326-1-git-send-email-pbonzini@redhat.com> <1436276739-50326-2-git-send-email-pbonzini@redhat.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5797 Lines: 168 On Tue, 2015-07-07 at 15:45 +0200, Paolo Bonzini wrote: > If there are no assigned devices, the guest PAT are not providing > any useful information and can be overridden to writeback; VMX > always does this because it has the "IPAT" bit in its extended > page table entries, but SVM does not have anything similar. > Hook into VFIO and legacy device assignment so that they > provide this information to KVM. > > Signed-off-by: Paolo Bonzini > --- > arch/x86/include/asm/kvm_host.h | 3 ++- > arch/x86/kvm/iommu.c | 2 ++ > arch/x86/kvm/x86.c | 18 ++++++++++++++++++ > include/linux/kvm_host.h | 18 +++++++++++++++++- > virt/kvm/vfio.c | 5 +++++ > 5 files changed, 44 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > index 2a7f5d782c33..7fe26ba9082e 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -602,8 +602,9 @@ struct kvm_arch { > struct list_head assigned_dev_head; > struct iommu_domain *iommu_domain; > bool iommu_noncoherent; > -#define __KVM_HAVE_ARCH_NONCOHERENT_DMA > +#define __KVM_HAVE_ARCH_VFIO_HOOKS Do we really want to tie these two things together under something that's not strictly a "vfio" option? Legacy assignment also makes use of these, as shown in this patch, but even if we consider that temporary until legacy assignment is removed, I can imagine platforms that might care about one but not the other. I don't really see the harm in using a separate #define, perhaps __KVM_HAVE_ARCH_ASSIGNED_DEVICE. Thanks, Alex > atomic_t noncoherent_dma_count; > + atomic_t assigned_device_count; > struct kvm_pic *vpic; > struct kvm_ioapic *vioapic; > struct kvm_pit *vpit; > diff --git a/arch/x86/kvm/iommu.c b/arch/x86/kvm/iommu.c > index 7dbced309ddb..5c520ebf6343 100644 > --- a/arch/x86/kvm/iommu.c > +++ b/arch/x86/kvm/iommu.c > @@ -200,6 +200,7 @@ int kvm_assign_device(struct kvm *kvm, struct pci_dev *pdev) > goto out_unmap; > } > > + kvm_arch_start_assignment(kvm); > pci_set_dev_assigned(pdev); > > dev_info(&pdev->dev, "kvm assign device\n"); > @@ -224,6 +225,7 @@ int kvm_deassign_device(struct kvm *kvm, struct pci_dev *pdev) > iommu_detach_device(domain, &pdev->dev); > > pci_clear_dev_assigned(pdev); > + kvm_arch_end_assignment(kvm); > > dev_info(&pdev->dev, "kvm deassign device\n"); > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index bbaf44e8f0d3..6e455875d2e4 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -8218,6 +8218,24 @@ bool kvm_arch_can_inject_async_page_present(struct kvm_vcpu *vcpu) > kvm_x86_ops->interrupt_allowed(vcpu); > } > > +void kvm_arch_start_assignment(struct kvm *kvm) > +{ > + atomic_inc(&kvm->arch.assigned_device_count); > +} > +EXPORT_SYMBOL_GPL(kvm_arch_start_assignment); > + > +void kvm_arch_end_assignment(struct kvm *kvm) > +{ > + atomic_dec(&kvm->arch.assigned_device_count); > +} > +EXPORT_SYMBOL_GPL(kvm_arch_end_assignment); > + > +bool kvm_arch_has_assigned_device(struct kvm *kvm) > +{ > + return atomic_read(&kvm->arch.assigned_device_count); > +} > +EXPORT_SYMBOL_GPL(kvm_arch_has_assigned_device); > + > void kvm_arch_register_noncoherent_dma(struct kvm *kvm) > { > atomic_inc(&kvm->arch.noncoherent_dma_count); > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h > index 9564fd78c547..56146fdb1ff0 100644 > --- a/include/linux/kvm_host.h > +++ b/include/linux/kvm_host.h > @@ -716,10 +716,13 @@ static inline void kvm_arch_free_vm(struct kvm *kvm) > } > #endif > > -#ifdef __KVM_HAVE_ARCH_NONCOHERENT_DMA > +#ifdef __KVM_HAVE_ARCH_VFIO_HOOKS > void kvm_arch_register_noncoherent_dma(struct kvm *kvm); > void kvm_arch_unregister_noncoherent_dma(struct kvm *kvm); > bool kvm_arch_has_noncoherent_dma(struct kvm *kvm); > +void kvm_arch_start_assignment(struct kvm *kvm); > +void kvm_arch_end_assignment(struct kvm *kvm); > +bool kvm_arch_has_assigned_device(struct kvm *kvm); > #else > static inline void kvm_arch_register_noncoherent_dma(struct kvm *kvm) > { > @@ -733,6 +736,19 @@ static inline bool kvm_arch_has_noncoherent_dma(struct kvm *kvm) > { > return false; > } > + > +static inline void kvm_arch_start_assignment(struct kvm *kvm) > +{ > +} > + > +static inline void kvm_arch_end_assignment(struct kvm *kvm) > +{ > +} > + > +static inline bool kvm_arch_has_assigned_device(struct kvm *kvm) > +{ > + return false; > +} > #endif > > static inline wait_queue_head_t *kvm_arch_vcpu_wq(struct kvm_vcpu *vcpu) > diff --git a/virt/kvm/vfio.c b/virt/kvm/vfio.c > index 620e37f741b8..1dd087da6f31 100644 > --- a/virt/kvm/vfio.c > +++ b/virt/kvm/vfio.c > @@ -155,6 +155,8 @@ static int kvm_vfio_set_group(struct kvm_device *dev, long attr, u64 arg) > list_add_tail(&kvg->node, &kv->group_list); > kvg->vfio_group = vfio_group; > > + kvm_arch_start_assignment(dev->kvm); > + > mutex_unlock(&kv->lock); > > kvm_vfio_update_coherency(dev); > @@ -190,6 +192,8 @@ static int kvm_vfio_set_group(struct kvm_device *dev, long attr, u64 arg) > break; > } > > + kvm_arch_end_assignment(dev->kvm); > + > mutex_unlock(&kv->lock); > > kvm_vfio_group_put_external_user(vfio_group); > @@ -239,6 +243,7 @@ static void kvm_vfio_destroy(struct kvm_device *dev) > kvm_vfio_group_put_external_user(kvg->vfio_group); > list_del(&kvg->node); > kfree(kvg); > + kvm_arch_end_assignment(dev->kvm); > } > > kvm_vfio_update_coherency(dev); -- 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/