From mboxrd@z Thu Jan 1 00:00:00 1970 From: eric.auger@linaro.org (Eric Auger) Date: Fri, 31 Jul 2015 15:22:00 +0200 Subject: [PATCH v2 14/15] KVM: arm64: implement MSI injection in ITS emulation In-Reply-To: <1436538111-4294-15-git-send-email-andre.przywara@arm.com> References: <1436538111-4294-1-git-send-email-andre.przywara@arm.com> <1436538111-4294-15-git-send-email-andre.przywara@arm.com> Message-ID: <55BB7678.5080105@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Andre, On 07/10/2015 04:21 PM, Andre Przywara wrote: > When userland wants to inject a MSI into the guest, we have to use > our data structures to find the LPI number and the VCPU to receive > the interrupt. > Use the wrapper functions to iterate the linked lists and find the > proper Interrupt Translation Table Entry. Then set the pending bit > in this ITTE to be later picked up by the LR handling code. Kick > the VCPU which is meant to handle this interrupt. > We provide a VGIC emulation model specific routine for the actual > MSI injection. The wrapper functions return an error for models not > (yet) implementing MSIs (like the GICv2 emulation). > We also provide the handler for the ITS "INT" command, which allows a > guest to trigger an MSI via the ITS command queue. > > Signed-off-by: Andre Przywara > --- > include/kvm/arm_vgic.h | 1 + > virt/kvm/arm/its-emul.c | 65 +++++++++++++++++++++++++++++++++++++++++++++ > virt/kvm/arm/its-emul.h | 2 ++ > virt/kvm/arm/vgic-v3-emul.c | 1 + > 4 files changed, 69 insertions(+) > > diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h > index 323c33a..9e1abf9 100644 > --- a/include/kvm/arm_vgic.h > +++ b/include/kvm/arm_vgic.h > @@ -149,6 +149,7 @@ struct vgic_vm_ops { > int (*map_resources)(struct kvm *, const struct vgic_params *); > bool (*queue_lpis)(struct kvm_vcpu *); > void (*unqueue_lpi)(struct kvm_vcpu *, int irq); > + int (*inject_msi)(struct kvm *, struct kvm_msi *); > }; > > struct vgic_io_device { > diff --git a/virt/kvm/arm/its-emul.c b/virt/kvm/arm/its-emul.c > index 89534c6..a1c12bb 100644 > --- a/virt/kvm/arm/its-emul.c > +++ b/virt/kvm/arm/its-emul.c > @@ -323,6 +323,55 @@ static bool handle_mmio_gits_idregs(struct kvm_vcpu *vcpu, > } > > /* > + * Translates an incoming MSI request into the redistributor (=VCPU) and > + * the associated LPI number. Sets the LPI pending bit and also marks the > + * VCPU as having a pending interrupt. > + */ > +int vits_inject_msi(struct kvm *kvm, struct kvm_msi *msi) > +{ > + struct vgic_dist *dist = &kvm->arch.vgic; > + struct vgic_its *its = &dist->its; > + struct its_itte *itte; > + int cpuid; > + bool inject = false; > + int ret = 0; > + > + if (!vgic_has_its(kvm)) > + return -ENODEV; > + > + if (!(msi->flags & KVM_MSI_VALID_DEVID)) > + return -EINVAL; I am currently reworking the GSI routing series according to latest comments (flag usage on userside and removal of EXTENDED_MSI type on kernel side as you suggested). Given the data path, kvm_send_userspace_msi (kvm_msi*) |_ kvm_set_msi (kvm_kernel_irq_routing_entry *) |_ kvm->arch.vgic.vm_ops.inject_msi (kvm_msi *) the above check is useless I think since in kvm_set_msi I need to populate a kvm_msi struct from a kernel routing entry struct. The kernel routing entry struct has no info about the validity of devid so I systematically sets the flag in kvm_msi. I am still dubious about not storing the KVM_MSI_VALID_DEVID info somewhere in the kernel routing entry struct. Best Regards Eric > + > + spin_lock(&its->lock); > + > + if (!its->enabled || !dist->lpis_enabled) { > + ret = -EAGAIN; > + goto out_unlock; > + } > + > + itte = find_itte(kvm, msi->devid, msi->data); > + /* Triggering an unmapped IRQ gets silently dropped. */ > + if (!itte || !itte->collection) > + goto out_unlock; > + > + cpuid = itte->collection->target_addr; > + __set_bit(cpuid, itte->pending); > + inject = itte->enabled; > + > +out_unlock: > + spin_unlock(&its->lock); > + > + if (inject) { > + spin_lock(&dist->lock); > + __set_bit(cpuid, dist->irq_pending_on_cpu); > + spin_unlock(&dist->lock); > + kvm_vcpu_kick(kvm_get_vcpu(kvm, cpuid)); > + } > + > + return ret; > +} > + > +/* > * Find all enabled and pending LPIs and queue them into the list > * registers. > * The dist lock is held by the caller. > @@ -787,6 +836,19 @@ static int vits_cmd_handle_movall(struct kvm *kvm, u64 *its_cmd) > return 0; > } > > +/* The INT command injects the LPI associated with that DevID/EvID pair. */ > +static int vits_cmd_handle_int(struct kvm *kvm, u64 *its_cmd) > +{ > + struct kvm_msi msi = { > + .data = its_cmd_get_id(its_cmd), > + .devid = its_cmd_get_deviceid(its_cmd), > + .flags = KVM_MSI_VALID_DEVID, > + }; > + > + vits_inject_msi(kvm, &msi); > + return 0; > +} > + > static int vits_handle_command(struct kvm_vcpu *vcpu, u64 *its_cmd) > { > u8 cmd = its_cmd_get_command(its_cmd); > @@ -817,6 +879,9 @@ static int vits_handle_command(struct kvm_vcpu *vcpu, u64 *its_cmd) > case GITS_CMD_MOVALL: > ret = vits_cmd_handle_movall(vcpu->kvm, its_cmd); > break; > + case GITS_CMD_INT: > + ret = vits_cmd_handle_int(vcpu->kvm, its_cmd); > + break; > case GITS_CMD_INV: > ret = vits_cmd_handle_inv(vcpu->kvm, its_cmd); > break; > diff --git a/virt/kvm/arm/its-emul.h b/virt/kvm/arm/its-emul.h > index 830524a..95e56a7 100644 > --- a/virt/kvm/arm/its-emul.h > +++ b/virt/kvm/arm/its-emul.h > @@ -36,6 +36,8 @@ void vgic_enable_lpis(struct kvm_vcpu *vcpu); > int vits_init(struct kvm *kvm); > void vits_destroy(struct kvm *kvm); > > +int vits_inject_msi(struct kvm *kvm, struct kvm_msi *msi); > + > bool vits_queue_lpis(struct kvm_vcpu *vcpu); > void vits_unqueue_lpi(struct kvm_vcpu *vcpu, int irq); > > diff --git a/virt/kvm/arm/vgic-v3-emul.c b/virt/kvm/arm/vgic-v3-emul.c > index 4132c26..30bf7035 100644 > --- a/virt/kvm/arm/vgic-v3-emul.c > +++ b/virt/kvm/arm/vgic-v3-emul.c > @@ -948,6 +948,7 @@ void vgic_v3_init_emulation(struct kvm *kvm) > dist->vm_ops.init_model = vgic_v3_init_model; > dist->vm_ops.destroy_model = vgic_v3_destroy_model; > dist->vm_ops.map_resources = vgic_v3_map_resources; > + dist->vm_ops.inject_msi = vits_inject_msi; > dist->vm_ops.queue_lpis = vits_queue_lpis; > dist->vm_ops.unqueue_lpi = vits_unqueue_lpi; > >