Implements kvm_vgic_[set|unset]_forward. Handle low-level VGIC programming: physical IRQ/guest IRQ mapping, list register cleanup, VGIC state machine. Also interacts with the irqchip.
Signed-off-by: Eric Auger <[email protected]> --- v2 -> v3: - on unforward, we do not compute & output the active state anymore. This means if the unforward happens while the physical IRQ is active, we will not VFIO mask the IRQ while deactiving it. If a new physical IRQ hits, the corresponding virtual IRQ might not be injected (hence lost) due to VGIC state machine. bypass rfc v2: - use irq_set_vcpu_affinity API - use irq_set_irqchip_state instead of chip->irq_eoi bypass rfc: - rename kvm_arch_{set|unset}_forward into kvm_vgic_{set|unset}_forward. Remove __KVM_HAVE_ARCH_HALT_GUEST. The function is bound to be called by ARM code only. v4 -> v5: - fix arm64 compilation issues, ie. also defines __KVM_HAVE_ARCH_HALT_GUEST for arm64 v3 -> v4: - code originally located in kvm_vfio_arm.c - kvm_arch_vfio_{set|unset}_forward renamed into kvm_arch_{set|unset}_forward - split into 2 functions (set/unset) since unset does not fail anymore - unset can be invoked at whatever time. Extra care is taken to handle transition in VGIC state machine, LR cleanup, ... v2 -> v3: - renaming of kvm_arch_set_fwd_state into kvm_arch_vfio_set_forward - takes a bool arg instead of kvm_fwd_irq_action enum - removal of KVM_VFIO_IRQ_CLEANUP - platform device check now happens here - more precise errors returned - irq_eoi handled externally to this patch (VGIC) - correct enable_irq bug done twice - reword the commit message - correct check of platform_bus_type - use raw_spin_lock_irqsave and check the validity of the handler --- include/kvm/arm_vgic.h | 6 ++ virt/kvm/arm/vgic.c | 149 +++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 155 insertions(+) diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h index 7ef9ce0..409ac0f 100644 --- a/include/kvm/arm_vgic.h +++ b/include/kvm/arm_vgic.h @@ -363,6 +363,12 @@ int kvm_vgic_unmap_phys_irq(struct kvm_vcpu *vcpu, struct irq_phys_map *map); bool kvm_vgic_get_phys_irq_active(struct irq_phys_map *map); void kvm_vgic_set_phys_irq_active(struct irq_phys_map *map, bool active); +int kvm_vgic_set_forward(struct kvm *kvm, + unsigned int host_irq, unsigned int guest_irq); + +void kvm_vgic_unset_forward(struct kvm *kvm, + unsigned int host_irq, unsigned int guest_irq); + #define irqchip_in_kernel(k) (!!((k)->arch.vgic.in_kernel)) #define vgic_initialized(k) (!!((k)->arch.vgic.nr_cpus)) #define vgic_ready(k) ((k)->arch.vgic.ready) diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c index 03a85b3..b15999a 100644 --- a/virt/kvm/arm/vgic.c +++ b/virt/kvm/arm/vgic.c @@ -2551,3 +2551,152 @@ int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e, { return 0; } + +/** + * kvm_vgic_set_forward - Set IRQ forwarding + * + * @kvm: handle to the VM + * @host_irq: physical IRQ number + * @guest_irq: virtual IRQ number + * + * This function is supposed to be called only if the IRQ + * is not in progress: ie. not active at GIC level and not + * currently under injection in the guest. The physical IRQ must + * also be disabled and the guest must have been exited and + * prevented from being re-entered. + */ +int kvm_vgic_set_forward(struct kvm *kvm, + unsigned int host_irq, + unsigned int guest_irq) +{ + struct irq_phys_map *map = NULL; + struct kvm_vcpu *vcpu = kvm_get_vcpu(kvm, 0); + int spi_id = guest_irq + VGIC_NR_PRIVATE_IRQS; + + kvm_debug("%s host_irq=%d guest_irq=%d\n", + __func__, host_irq, guest_irq); + + if (!vcpu) + return 0; + + irq_set_vcpu_affinity(host_irq, vcpu); + /* + * next physical IRQ will be be handled as forwarded + * by the host (priority drop only) + */ + + map = kvm_vgic_map_phys_irq(vcpu, spi_id, host_irq, false); + /* + * next guest_irq injection will be considered as + * forwarded and next flush will program LR + * without maintenance IRQ but with HW bit set + */ + return !map; +} + +/** + * kvm_vgic_unset_forward - Unset IRQ forwarding + * + * @kvm: handle to the VM + * @host_irq: physical IRQ number + * @guest_irq: virtual IRQ number + * + * This function must be called when the host_irq is disabled + * and guest has been exited and prevented from being re-entered. + * + */ +void kvm_vgic_unset_forward(struct kvm *kvm, + unsigned int host_irq, + unsigned int guest_irq) +{ + struct kvm_vcpu *vcpu = kvm_get_vcpu(kvm, 0); + struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu; + struct vgic_dist *dist = &kvm->arch.vgic; + int ret, lr; + struct vgic_lr vlr; + int spi_id = guest_irq + VGIC_NR_PRIVATE_IRQS; + bool queued = false, needs_deactivate = true; + struct irq_phys_map *map; + bool active; + + kvm_debug("%s host_irq=%d guest_irq=%d\n", + __func__, host_irq, guest_irq); + + spin_lock(&dist->lock); + + irq_get_irqchip_state(host_irq, IRQCHIP_STATE_ACTIVE, &active); + + if (!vcpu) + goto out; + + map = vgic_irq_map_search(vcpu, spi_id); + BUG_ON(!map); + ret = kvm_vgic_unmap_phys_irq(vcpu, map); + BUG_ON(ret); + /* + * subsequent update_irq_pending or flush will handle this + * irq as not forwarded + */ + if (likely(!(active))) { + /* + * the IRQ was not active. let's simply prepare the states + * for subsequent non forwarded injection. + */ + vgic_dist_irq_clear_level(vcpu, spi_id); + vgic_dist_irq_clear_pending(vcpu, spi_id); + vgic_irq_clear_queued(vcpu, spi_id); + needs_deactivate = false; + goto out; + } + + /* is there any list register with valid state? */ + lr = vgic_cpu->vgic_irq_lr_map[spi_id]; + if (lr != LR_EMPTY) { + vlr = vgic_get_lr(vcpu, lr); + if (vlr.state & LR_STATE_MASK) + queued = true; + } + + if (!queued) { + vgic_irq_clear_queued(vcpu, spi_id); + if (vgic_dist_irq_is_pending(vcpu, spi_id)) { + /* + * IRQ is injected but not yet queued. LR will be + * written with EOI_INT and process_maintenance will + * reset the states: queued, level(resampler). Pending + * will be reset on flush. + */ + vgic_dist_irq_set_level(vcpu, spi_id); + } else { + /* + * We are somewhere before the update_irq_pending. + * we can't be sure the virtual IRQ will ever be + * injected (due to previous disable_irq). + * Let's simply clear the level which was not correctly + * modelled in forwarded state. + */ + vgic_dist_irq_clear_level(vcpu, spi_id); + } + goto out; + } + + /* + * the virtual IRQ is queued and a valid LR exists, let's patch it so + * that when EOI happens a maintenance IRQ gets triggered + */ + vlr.state |= LR_EOI_INT; + vgic_set_lr(vcpu, lr, vlr); + + vgic_dist_irq_set_level(vcpu, spi_id); + vgic_dist_irq_set_pending(vcpu, spi_id); + vgic_irq_set_queued(vcpu, spi_id); + /* The maintenance IRQ will reset all states above */ + +out: + irq_set_irqchip_state(host_irq, IRQCHIP_STATE_ACTIVE, false); + irq_set_vcpu_affinity(host_irq, NULL); + /* next occurrence will be deactivated by the host */ + + spin_unlock(&dist->lock); +} + -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
