Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752588AbaKWSj2 (ORCPT ); Sun, 23 Nov 2014 13:39:28 -0500 Received: from mail-wi0-f178.google.com ([209.85.212.178]:52399 "EHLO mail-wi0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752265AbaKWShj (ORCPT ); Sun, 23 Nov 2014 13:37:39 -0500 From: Eric Auger To: eric.auger@st.com, eric.auger@linaro.org, christoffer.dall@linaro.org, marc.zyngier@arm.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, alex.williamson@redhat.com, joel.schopp@amd.com, kim.phillips@freescale.com, paulus@samba.org, gleb@kernel.org, pbonzini@redhat.com, agraf@suse.de Cc: linux-kernel@vger.kernel.org, patches@linaro.org, will.deacon@arm.com, a.motakis@virtualopensystems.com, a.rigo@virtualopensystems.com, john.liuli@huawei.com, ming.lei@canonical.com, feng.wu@intel.com Subject: [PATCH v3 4/8] KVM: kvm-vfio: User API for IRQ forwarding Date: Sun, 23 Nov 2014 19:35:56 +0100 Message-Id: <1416767760-14487-5-git-send-email-eric.auger@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1416767760-14487-1-git-send-email-eric.auger@linaro.org> References: <1416767760-14487-1-git-send-email-eric.auger@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch adds and document a new KVM_DEV_VFIO_DEVICE group and 2 device attributes: KVM_DEV_VFIO_DEVICE_FORWARD_IRQ, KVM_DEV_VFIO_DEVICE_UNFORWARD_IRQ. The purpose is to be able to set a VFIO device IRQ as forwarded or not forwarded. the command takes as argument a handle to a new struct named kvm_arch_forwarded_irq. Signed-off-by: Eric Auger --- v2 -> v3: - rework vfio kvm device documentation - reword commit message and title - add subindex in kvm_arch_forwarded_irq to be closer to VFIO API - forwarding state can only be changed with VFIO IRQ signaling is off v1 -> v2: - struct kvm_arch_forwarded_irq moved from arch/arm/include/uapi/asm/kvm.h to include/uapi/linux/kvm.h also irq_index renamed into index and guest_irq renamed into gsi - ASSIGN/DEASSIGN renamed into FORWARD/UNFORWARD --- Documentation/virtual/kvm/devices/vfio.txt | 34 ++++++++++++++++++++++++------ include/uapi/linux/kvm.h | 10 +++++++++ 2 files changed, 38 insertions(+), 6 deletions(-) diff --git a/Documentation/virtual/kvm/devices/vfio.txt b/Documentation/virtual/kvm/devices/vfio.txt index ef51740..f7aff29 100644 --- a/Documentation/virtual/kvm/devices/vfio.txt +++ b/Documentation/virtual/kvm/devices/vfio.txt @@ -4,15 +4,24 @@ VFIO virtual device Device types supported: KVM_DEV_TYPE_VFIO -Only one VFIO instance may be created per VM. The created device -tracks VFIO groups in use by the VM and features of those groups -important to the correctness and acceleration of the VM. As groups -are enabled and disabled for use by the VM, KVM should be updated -about their presence. When registered with KVM, a reference to the -VFIO-group is held by KVM. +Only one VFIO instance may be created per VM. + +The created device tracks VFIO groups in use by the VM and features +of those groups important to the correctness and acceleration of +the VM. As groups are enabled and disabled for use by the VM, KVM +should be updated about their presence. When registered with KVM, +a reference to the VFIO-group is held by KVM. + +The device also tracks & enable VFIO device forwarded IRQs, if any. +A physical forwarded IRQ is directly completed by the guest. This +requires HW support in the interrupt controller which must be able +to automatically complete the physical IRQ when it detects the guest +has completed the corresponding virtual IRQ. The modality sometimes +is named direct EOI. Groups: KVM_DEV_VFIO_GROUP + KVM_DEV_VFIO_DEVICE KVM_DEV_VFIO_GROUP attributes: KVM_DEV_VFIO_GROUP_ADD: Add a VFIO group to VFIO-KVM device tracking @@ -20,3 +29,16 @@ KVM_DEV_VFIO_GROUP attributes: For each, kvm_device_attr.addr points to an int32_t file descriptor for the VFIO group. + +KVM_DEV_VFIO_DEVICE attributes: + KVM_DEV_VFIO_DEVICE_FORWARD_IRQ: set a VFIO device IRQ as forwarded + KVM_DEV_VFIO_DEVICE_UNFORWARD_IRQ: set a VFIO device IRQ as not forwarded + +For each, kvm_device_attr.addr points to a kvm_arch_forwarded_irq struct. + +The forwarded state can only be changed when the VFIO signaling mechanism +for this physical IRQ is not set. In other words, forwarding must be +activated before VFIO_DEVICE_SET_IRQS has been called to trigger the IRQ +or associate an eventfd to it. Unforwarding can only be called while the +signaling has been disabled with VFIO_DEVICE_SET_IRQS. If this condition is +not satisfied, the command returns an -EBUSY. diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 6076882..a269a42 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -946,6 +946,9 @@ struct kvm_device_attr { #define KVM_DEV_VFIO_GROUP 1 #define KVM_DEV_VFIO_GROUP_ADD 1 #define KVM_DEV_VFIO_GROUP_DEL 2 +#define KVM_DEV_VFIO_DEVICE 2 +#define KVM_DEV_VFIO_DEVICE_FORWARD_IRQ 1 +#define KVM_DEV_VFIO_DEVICE_UNFORWARD_IRQ 2 enum kvm_device_type { KVM_DEV_TYPE_FSL_MPIC_20 = 1, @@ -963,6 +966,13 @@ enum kvm_device_type { KVM_DEV_TYPE_MAX, }; +struct kvm_arch_forwarded_irq { + __u32 fd; /* file desciptor of the VFIO device */ + __u32 index; /* VFIO device IRQ index */ + __u32 subindex; /* VFIO device IRQ subindex */ + __u32 gsi; /* gsi, ie. virtual IRQ number */ +}; + /* * ioctls for VM fds */ -- 1.9.1 -- 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/