Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753549Ab3JDKDJ (ORCPT ); Fri, 4 Oct 2013 06:03:09 -0400 Received: from mail-pb0-f54.google.com ([209.85.160.54]:54617 "EHLO mail-pb0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750974Ab3JDKDH (ORCPT ); Fri, 4 Oct 2013 06:03:07 -0400 Message-ID: <524E9250.4030904@ozlabs.ru> Date: Fri, 04 Oct 2013 20:02:56 +1000 From: Alexey Kardashevskiy User-Agent: Mozilla/5.0 (X11; Linux i686 on x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.0 MIME-Version: 1.0 To: Alex Williamson , gleb@redhat.com CC: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Subject: Re: [PATCH 3/4] kvm: Create non-coherent DMA registeration References: <20131001200757.31715.22994.stgit@bling.home> <20131001201518.31715.50233.stgit@bling.home> In-Reply-To: <20131001201518.31715.50233.stgit@bling.home> Content-Type: text/plain; charset=KOI8-R Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4933 Lines: 150 On 10/02/2013 06:15 AM, Alex Williamson wrote: > We currently use some ad-hoc arch variables tied to legacy KVM device > assignment to manage emulation of instructions that depend on whether > non-coherent DMA is present. Create an interface for this so that we > can register coherency for other devices, like vfio assigned devices. > > Signed-off-by: Alex Williamson > --- > arch/x86/include/asm/kvm_host.h | 2 ++ > arch/x86/kvm/vmx.c | 3 +-- > arch/x86/kvm/x86.c | 21 +++++++++++++++++++-- > include/linux/kvm_host.h | 19 +++++++++++++++++++ > virt/kvm/iommu.c | 6 ++++++ > 5 files changed, 47 insertions(+), 4 deletions(-) > > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > index 1b6b5f9..50c1e9c1 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -558,6 +558,8 @@ struct kvm_arch { > struct list_head assigned_dev_head; > struct iommu_domain *iommu_domain; > bool iommu_noncoherent; > +#define __KVM_HAVE_ARCH_NONCOHERENT_DMA > + atomic_t noncoherent_dma_count; > struct kvm_pic *vpic; > struct kvm_ioapic *vioapic; > struct kvm_pit *vpit; > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index 8b2270a..a982c9e 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -7404,8 +7404,7 @@ static u64 vmx_get_mt_mask(struct kvm_vcpu *vcpu, gfn_t gfn, bool is_mmio) > */ > if (is_mmio) > ret = MTRR_TYPE_UNCACHABLE << VMX_EPT_MT_EPTE_SHIFT; > - else if (vcpu->kvm->arch.iommu_domain && > - vcpu->kvm->arch.iommu_noncoherent) > + else if (kvm_arch_has_noncoherent_dma(vcpu->kvm)) > ret = kvm_get_guest_memory_type(vcpu, gfn) << > VMX_EPT_MT_EPTE_SHIFT; > else > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index b1231b0..feec86d 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -2715,8 +2715,7 @@ static void wbinvd_ipi(void *garbage) > > static bool need_emulate_wbinvd(struct kvm_vcpu *vcpu) > { > - return vcpu->kvm->arch.iommu_domain && > - vcpu->kvm->arch.iommu_noncoherent; > + return kvm_arch_has_noncoherent_dma(vcpu->kvm); > } > > void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) > @@ -7420,6 +7419,24 @@ bool kvm_arch_can_inject_async_page_present(struct kvm_vcpu *vcpu) > kvm_x86_ops->interrupt_allowed(vcpu); > } > > +void kvm_arch_register_noncoherent_dma(struct kvm *kvm) > +{ > + atomic_inc(&kvm->arch.noncoherent_dma_count); > +} > +EXPORT_SYMBOL_GPL(kvm_arch_register_noncoherent_dma); > + > +void kvm_arch_unregister_noncoherent_dma(struct kvm *kvm) > +{ > + atomic_dec(&kvm->arch.noncoherent_dma_count); > +} > +EXPORT_SYMBOL_GPL(kvm_arch_unregister_noncoherent_dma); > + > +bool kvm_arch_has_noncoherent_dma(struct kvm *kvm) > +{ > + return atomic_read(&kvm->arch.noncoherent_dma_count); > +} > +EXPORT_SYMBOL_GPL(kvm_arch_has_noncoherent_dma); > + > EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_exit); > EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_inj_virq); > EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_page_fault); > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h > index f46da56..e239c93 100644 > --- a/include/linux/kvm_host.h > +++ b/include/linux/kvm_host.h > @@ -671,6 +671,25 @@ static inline void kvm_arch_free_vm(struct kvm *kvm) > } > #endif > > +#ifdef __KVM_HAVE_ARCH_NONCOHERENT_DMA > +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); > +#else > +static inline void kvm_arch_register_noncoherent_dma(void) Wrong prototype here and below, must include *kvm. > +{ > +} > + > +static inline void kvm_arch_unregister_noncoherent_dma(void) > +{ > +} > + > +static inline bool kvm_arch_has_noncoherent_dma(void) > +{ > + return false; > +} > +#endif > + > static inline wait_queue_head_t *kvm_arch_vcpu_wq(struct kvm_vcpu *vcpu) > { > #ifdef __KVM_HAVE_ARCH_WQP > diff --git a/virt/kvm/iommu.c b/virt/kvm/iommu.c > index 9cde444..0a54456 100644 > --- a/virt/kvm/iommu.c > +++ b/virt/kvm/iommu.c > @@ -140,6 +140,9 @@ static int kvm_iommu_map_memslots(struct kvm *kvm) > struct kvm_memslots *slots; > struct kvm_memory_slot *memslot; > > + if (kvm->arch.iommu_noncoherent) > + kvm_arch_register_noncoherent_dma(kvm); > + > idx = srcu_read_lock(&kvm->srcu); > slots = kvm_memslots(kvm); > > @@ -335,6 +338,9 @@ static int kvm_iommu_unmap_memslots(struct kvm *kvm) > > srcu_read_unlock(&kvm->srcu, idx); > > + if (kvm->arch.iommu_noncoherent) > + kvm_arch_unregister_noncoherent_dma(kvm); > + > return 0; > } > > -- Alexey -- 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/