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AJvYcCVEDvd5ggHd3Eb3n3dmce69RMedqRqQpqUL5hf3RqjTQLd3UJ0pYpEecCY0st4DW/sm2stJqPXOcg/1y3s=@vger.kernel.org X-Gm-Message-State: AOJu0YyuF2Yc+6g8OGrvWOVNyFujoC5ZdPh/pbEJS04DwoBkgwNaMOXD EKjJbvXQ5ul4oU+VhF7W/vKhLhErV7FA5z0bwYi+2CX+CCwWEWhDmOtYM4c0fTAMvz8nHYrRm1G 3NNXUTw== X-Google-Smtp-Source: AGHT+IEyipb6CSG32fPdkBnIH7AX3Zq2Z2jB0QyZC6+PFK6cFG6DODigZnV9KthZcAYR6p98mMBWNxQJtN0= X-Received: from pjqq12.prod.google.com ([2002:a17:90b:584c:b0:312:ea08:fa64]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:903:18c:b0:234:c8cf:a0e6 with SMTP id d9443c01a7336-23641b199c4mr70063175ad.24.1749682022639; Wed, 11 Jun 2025 15:47:02 -0700 (PDT) Reply-To: Sean Christopherson Date: Wed, 11 Jun 2025 15:45:07 -0700 In-Reply-To: <20250611224604.313496-2-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250611224604.313496-2-seanjc@google.com> X-Mailer: git-send-email 2.50.0.rc1.591.g9c95f17f64-goog Message-ID: <20250611224604.313496-6-seanjc@google.com> Subject: [PATCH v3 04/62] KVM: SVM: Track per-vCPU IRTEs using kvm_kernel_irqfd structure From: Sean Christopherson To: Marc Zyngier , Oliver Upton , Sean Christopherson , Paolo Bonzini , Joerg Roedel , David Woodhouse , Lu Baolu Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, kvm@vger.kernel.org, iommu@lists.linux.dev, linux-kernel@vger.kernel.org, Sairaj Kodilkar , Vasant Hegde , Maxim Levitsky , Joao Martins , Francesco Lavra , David Matlack Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Track the IRTEs that are posting to an SVM vCPU via the associated irqfd structure and GSI routing instead of dynamically allocating a separate data structure. In addition to eliminating an atomic allocation, this will allow hoisting much of the IRTE update logic to common x86. Cc: Sairaj Kodilkar Signed-off-by: Sean Christopherson --- arch/x86/kvm/svm/avic.c | 71 +++++++++++++++------------------------ arch/x86/kvm/svm/svm.h | 10 +++--- include/linux/kvm_irqfd.h | 3 ++ 3 files changed, 36 insertions(+), 48 deletions(-) diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c index adacf00d6664..d33c01379421 100644 --- a/arch/x86/kvm/svm/avic.c +++ b/arch/x86/kvm/svm/avic.c @@ -75,14 +75,6 @@ static bool next_vm_id_wrapped =3D 0; static DEFINE_SPINLOCK(svm_vm_data_hash_lock); bool x2avic_enabled; =20 -/* - * This is a wrapper of struct amd_iommu_ir_data. - */ -struct amd_svm_iommu_ir { - struct list_head node; /* Used by SVM for per-vcpu ir_list */ - void *data; /* Storing pointer to struct amd_ir_data */ -}; - static void avic_activate_vmcb(struct vcpu_svm *svm) { struct vmcb *vmcb =3D svm->vmcb01.ptr; @@ -746,8 +738,8 @@ static int avic_set_pi_irte_mode(struct kvm_vcpu *vcpu,= bool activate) { int ret =3D 0; unsigned long flags; - struct amd_svm_iommu_ir *ir; struct vcpu_svm *svm =3D to_svm(vcpu); + struct kvm_kernel_irqfd *irqfd; =20 if (!kvm_arch_has_assigned_device(vcpu->kvm)) return 0; @@ -761,11 +753,11 @@ static int avic_set_pi_irte_mode(struct kvm_vcpu *vcp= u, bool activate) if (list_empty(&svm->ir_list)) goto out; =20 - list_for_each_entry(ir, &svm->ir_list, node) { + list_for_each_entry(irqfd, &svm->ir_list, vcpu_list) { if (activate) - ret =3D amd_iommu_activate_guest_mode(ir->data); + ret =3D amd_iommu_activate_guest_mode(irqfd->irq_bypass_data); else - ret =3D amd_iommu_deactivate_guest_mode(ir->data); + ret =3D amd_iommu_deactivate_guest_mode(irqfd->irq_bypass_data); if (ret) break; } @@ -774,27 +766,30 @@ static int avic_set_pi_irte_mode(struct kvm_vcpu *vcp= u, bool activate) return ret; } =20 -static void svm_ir_list_del(struct vcpu_svm *svm, struct amd_iommu_pi_data= *pi) +static void svm_ir_list_del(struct vcpu_svm *svm, + struct kvm_kernel_irqfd *irqfd, + struct amd_iommu_pi_data *pi) { unsigned long flags; - struct amd_svm_iommu_ir *cur; + struct kvm_kernel_irqfd *cur; =20 spin_lock_irqsave(&svm->ir_list_lock, flags); - list_for_each_entry(cur, &svm->ir_list, node) { - if (cur->data !=3D pi->ir_data) + list_for_each_entry(cur, &svm->ir_list, vcpu_list) { + if (cur->irq_bypass_data !=3D pi->ir_data) continue; - list_del(&cur->node); - kfree(cur); + if (WARN_ON_ONCE(cur !=3D irqfd)) + continue; + list_del(&irqfd->vcpu_list); break; } spin_unlock_irqrestore(&svm->ir_list_lock, flags); } =20 -static int svm_ir_list_add(struct vcpu_svm *svm, struct amd_iommu_pi_data = *pi) +static int svm_ir_list_add(struct vcpu_svm *svm, + struct kvm_kernel_irqfd *irqfd, + struct amd_iommu_pi_data *pi) { - int ret =3D 0; unsigned long flags; - struct amd_svm_iommu_ir *ir; u64 entry; =20 if (WARN_ON_ONCE(!pi->ir_data)) @@ -811,25 +806,14 @@ static int svm_ir_list_add(struct vcpu_svm *svm, stru= ct amd_iommu_pi_data *pi) struct kvm_vcpu *prev_vcpu =3D kvm_get_vcpu_by_id(kvm, vcpu_id); struct vcpu_svm *prev_svm; =20 - if (!prev_vcpu) { - ret =3D -EINVAL; - goto out; - } + if (!prev_vcpu) + return -EINVAL; =20 prev_svm =3D to_svm(prev_vcpu); - svm_ir_list_del(prev_svm, pi); + svm_ir_list_del(prev_svm, irqfd, pi); } =20 - /** - * Allocating new amd_iommu_pi_data, which will get - * add to the per-vcpu ir_list. - */ - ir =3D kzalloc(sizeof(struct amd_svm_iommu_ir), GFP_ATOMIC | __GFP_ACCOUN= T); - if (!ir) { - ret =3D -ENOMEM; - goto out; - } - ir->data =3D pi->ir_data; + irqfd->irq_bypass_data =3D pi->ir_data; =20 spin_lock_irqsave(&svm->ir_list_lock, flags); =20 @@ -844,10 +828,9 @@ static int svm_ir_list_add(struct vcpu_svm *svm, struc= t amd_iommu_pi_data *pi) amd_iommu_update_ga(entry & AVIC_PHYSICAL_ID_ENTRY_HOST_PHYSICAL_ID_MASK, true, pi->ir_data); =20 - list_add(&ir->node, &svm->ir_list); + list_add(&irqfd->vcpu_list, &svm->ir_list); spin_unlock_irqrestore(&svm->ir_list_lock, flags); -out: - return ret; + return 0; } =20 /* @@ -951,7 +934,7 @@ int avic_pi_update_irte(struct kvm_kernel_irqfd *irqfd,= struct kvm *kvm, * scheduling information in IOMMU irte. */ if (!ret && pi.is_guest_mode) - svm_ir_list_add(svm, &pi); + svm_ir_list_add(svm, irqfd, &pi); } =20 if (!ret && svm) { @@ -992,7 +975,7 @@ int avic_pi_update_irte(struct kvm_kernel_irqfd *irqfd,= struct kvm *kvm, =20 vcpu =3D kvm_get_vcpu_by_id(kvm, id); if (vcpu) - svm_ir_list_del(to_svm(vcpu), &pi); + svm_ir_list_del(to_svm(vcpu), irqfd, &pi); } } out: @@ -1004,8 +987,8 @@ static inline int avic_update_iommu_vcpu_affinity(struct kvm_vcpu *vcpu, int cpu, bool r) { int ret =3D 0; - struct amd_svm_iommu_ir *ir; struct vcpu_svm *svm =3D to_svm(vcpu); + struct kvm_kernel_irqfd *irqfd; =20 lockdep_assert_held(&svm->ir_list_lock); =20 @@ -1019,8 +1002,8 @@ avic_update_iommu_vcpu_affinity(struct kvm_vcpu *vcpu= , int cpu, bool r) if (list_empty(&svm->ir_list)) return 0; =20 - list_for_each_entry(ir, &svm->ir_list, node) { - ret =3D amd_iommu_update_ga(cpu, r, ir->data); + list_for_each_entry(irqfd, &svm->ir_list, vcpu_list) { + ret =3D amd_iommu_update_ga(cpu, r, irqfd->irq_bypass_data); if (ret) return ret; } diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index b35fce30d923..cc27877d69ae 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -310,10 +310,12 @@ struct vcpu_svm { u64 *avic_physical_id_cache; =20 /* - * Per-vcpu list of struct amd_svm_iommu_ir: - * This is used mainly to store interrupt remapping information used - * when update the vcpu affinity. This avoids the need to scan for - * IRTE and try to match ga_tag in the IOMMU driver. + * Per-vCPU list of irqfds that are eligible to post IRQs directly to + * the vCPU (a.k.a. device posted IRQs, a.k.a. IRQ bypass). The list + * is used to reconfigure IRTEs when the vCPU is loaded/put (to set the + * target pCPU), when AVIC is toggled on/off (to (de)activate bypass), + * and if the irqfd becomes ineligible for posting (to put the IRTE + * back into remapped mode). */ struct list_head ir_list; spinlock_t ir_list_lock; diff --git a/include/linux/kvm_irqfd.h b/include/linux/kvm_irqfd.h index 8ad43692e3bb..6510a48e62aa 100644 --- a/include/linux/kvm_irqfd.h +++ b/include/linux/kvm_irqfd.h @@ -59,6 +59,9 @@ struct kvm_kernel_irqfd { struct work_struct shutdown; struct irq_bypass_consumer consumer; struct irq_bypass_producer *producer; + + struct list_head vcpu_list; + void *irq_bypass_data; }; =20 #endif /* __LINUX_KVM_IRQFD_H */ --=20 2.50.0.rc1.591.g9c95f17f64-goog