From 196b136498b35f1cd787b84465f235e69dbc757c Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Fri, 27 Oct 2017 15:28:39 +0100 Subject: [PATCH] KVM: arm/arm64: GICv4: Wire mapping/unmapping of VLPIs in VFIO irq bypass Let's use the irq bypass mechanism also used for x86 posted interrupts to intercept the virtual PCIe endpoint configuration and establish our LPI->VLPI mapping. Reviewed-by: Christoffer Dall Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall --- include/kvm/arm_vgic.h | 8 +++ virt/kvm/arm/arm.c | 6 ++- virt/kvm/arm/vgic/vgic-v4.c | 104 ++++++++++++++++++++++++++++++++++++ 3 files changed, 116 insertions(+), 2 deletions(-) diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h index 7eeb6c2a2f9c..2f750c770bf2 100644 --- a/include/kvm/arm_vgic.h +++ b/include/kvm/arm_vgic.h @@ -373,4 +373,12 @@ int kvm_vgic_setup_default_irq_routing(struct kvm *kvm); int kvm_vgic_set_owner(struct kvm_vcpu *vcpu, unsigned int intid, void *owner); +struct kvm_kernel_irq_routing_entry; + +int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int irq, + struct kvm_kernel_irq_routing_entry *irq_entry); + +int kvm_vgic_v4_unset_forwarding(struct kvm *kvm, int irq, + struct kvm_kernel_irq_routing_entry *irq_entry); + #endif /* __KVM_ARM_VGIC_H */ diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c index e1e947fe9bc2..34a15c0c65ab 100644 --- a/virt/kvm/arm/arm.c +++ b/virt/kvm/arm/arm.c @@ -1471,7 +1471,8 @@ int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *cons, struct kvm_kernel_irqfd *irqfd = container_of(cons, struct kvm_kernel_irqfd, consumer); - return 0; + return kvm_vgic_v4_set_forwarding(irqfd->kvm, prod->irq, + &irqfd->irq_entry); } void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons, struct irq_bypass_producer *prod) @@ -1479,7 +1480,8 @@ void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons, struct kvm_kernel_irqfd *irqfd = container_of(cons, struct kvm_kernel_irqfd, consumer); - return; + kvm_vgic_v4_unset_forwarding(irqfd->kvm, prod->irq, + &irqfd->irq_entry); } void kvm_arch_irq_bypass_stop(struct irq_bypass_consumer *cons) diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c index c794f0cef09e..2edfe23c8238 100644 --- a/virt/kvm/arm/vgic/vgic-v4.c +++ b/virt/kvm/arm/vgic/vgic-v4.c @@ -18,6 +18,7 @@ #include #include #include +#include #include "vgic.h" @@ -81,3 +82,106 @@ void vgic_v4_teardown(struct kvm *kvm) its_vm->nr_vpes = 0; its_vm->vpes = NULL; } + +static struct vgic_its *vgic_get_its(struct kvm *kvm, + struct kvm_kernel_irq_routing_entry *irq_entry) +{ + struct kvm_msi msi = (struct kvm_msi) { + .address_lo = irq_entry->msi.address_lo, + .address_hi = irq_entry->msi.address_hi, + .data = irq_entry->msi.data, + .flags = irq_entry->msi.flags, + .devid = irq_entry->msi.devid, + }; + + return vgic_msi_to_its(kvm, &msi); +} + +int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq, + struct kvm_kernel_irq_routing_entry *irq_entry) +{ + struct vgic_its *its; + struct vgic_irq *irq; + struct its_vlpi_map map; + int ret; + + if (!vgic_supports_direct_msis(kvm)) + return 0; + + /* + * Get the ITS, and escape early on error (not a valid + * doorbell for any of our vITSs). + */ + its = vgic_get_its(kvm, irq_entry); + if (IS_ERR(its)) + return 0; + + mutex_lock(&its->its_lock); + + /* Perform then actual DevID/EventID -> LPI translation. */ + ret = vgic_its_resolve_lpi(kvm, its, irq_entry->msi.devid, + irq_entry->msi.data, &irq); + if (ret) + goto out; + + /* + * Emit the mapping request. If it fails, the ITS probably + * isn't v4 compatible, so let's silently bail out. Holding + * the ITS lock should ensure that nothing can modify the + * target vcpu. + */ + map = (struct its_vlpi_map) { + .vm = &kvm->arch.vgic.its_vm, + .vpe = &irq->target_vcpu->arch.vgic_cpu.vgic_v3.its_vpe, + .vintid = irq->intid, + .properties = ((irq->priority & 0xfc) | + (irq->enabled ? LPI_PROP_ENABLED : 0) | + LPI_PROP_GROUP1), + .db_enabled = true, + }; + + ret = its_map_vlpi(virq, &map); + if (ret) + goto out; + + irq->hw = true; + irq->host_irq = virq; + +out: + mutex_unlock(&its->its_lock); + return ret; +} + +int kvm_vgic_v4_unset_forwarding(struct kvm *kvm, int virq, + struct kvm_kernel_irq_routing_entry *irq_entry) +{ + struct vgic_its *its; + struct vgic_irq *irq; + int ret; + + if (!vgic_supports_direct_msis(kvm)) + return 0; + + /* + * Get the ITS, and escape early on error (not a valid + * doorbell for any of our vITSs). + */ + its = vgic_get_its(kvm, irq_entry); + if (IS_ERR(its)) + return 0; + + mutex_lock(&its->its_lock); + + ret = vgic_its_resolve_lpi(kvm, its, irq_entry->msi.devid, + irq_entry->msi.data, &irq); + if (ret) + goto out; + + WARN_ON(!(irq->hw && irq->host_irq == virq)); + irq->hw = false; + ret = its_unmap_vlpi(virq); + +out: + mutex_unlock(&its->its_lock); + return ret; +}