Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754934Ab3JDOxo (ORCPT ); Fri, 4 Oct 2013 10:53:44 -0400 Received: from mx1.redhat.com ([209.132.183.28]:39832 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754224Ab3JDOxn (ORCPT ); Fri, 4 Oct 2013 10:53:43 -0400 Message-ID: <1380898420.2673.192.camel@ul30vt.home> Subject: Re: [PATCH 3/4] kvm: Create non-coherent DMA registeration From: Alex Williamson To: Alexey Kardashevskiy Cc: gleb@redhat.com, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Date: Fri, 04 Oct 2013 08:53:40 -0600 In-Reply-To: <524E9250.4030904@ozlabs.ru> References: <20131001200757.31715.22994.stgit@bling.home> <20131001201518.31715.50233.stgit@bling.home> <524E9250.4030904@ozlabs.ru> 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: 5284 Lines: 153 On Fri, 2013-10-04 at 20:02 +1000, Alexey Kardashevskiy wrote: > 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. D'oh. Thanks > > +{ > > +} > > + > > +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; > > } > > > > > > -- 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/