From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Auger Subject: [RFC v7 1/7] KVM: api: pass the devid in the msi routing entry Date: Mon, 18 Jul 2016 13:25:51 +0000 Message-ID: <1468848357-2331-2-git-send-email-eric.auger@redhat.com> References: <1468848357-2331-1-git-send-email-eric.auger@redhat.com> Cc: drjones@redhat.com, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, pbonzini@redhat.com To: eric.auger@redhat.com, eric.auger.pro@gmail.com, marc.zyngier@arm.com, christoffer.dall@linaro.org, andre.przywara@arm.com Return-path: Received: from mx1.redhat.com ([209.132.183.28]:51126 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751205AbcGRN0I (ORCPT ); Mon, 18 Jul 2016 09:26:08 -0400 In-Reply-To: <1468848357-2331-1-git-send-email-eric.auger@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On ARM, the MSI msg (address and data) comes along with out-of-band device ID information. The device ID encodes the device that writes the MSI msg. Let's convey the device id in kvm_irq_routing_msi and use KVM_MSI_VALID_DEVID flag value in kvm_irq_routing_entry to indicate the msi devid is populated. Signed-off-by: Eric Auger Reviewed-by: Andre Przywara --- v6 -> v7: - Added Andre's R-b v4 -> v5: - some rephrasing in api.txt according to Christoffer's comments v2 -> v3: - replace usage of KVM_IRQ_ROUTING_EXTENDED_MSI type by usage of KVM_MSI_VALID_DEVID flag - add note about KVM_CAP_MSI_DEVID capability v1 -> v2: - devid id passed in kvm_irq_routing_msi instead of in kvm_irq_routing_entry RFC -> PATCH - remove kvm_irq_routing_extended_msi and use union instead --- Documentation/virtual/kvm/api.txt | 19 +++++++++++++++++-- include/uapi/linux/kvm.h | 5 ++++- 2 files changed, 21 insertions(+), 3 deletions(-) diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index f60b137..0065c8e 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -1468,7 +1468,11 @@ struct kvm_irq_routing_entry { #define KVM_IRQ_ROUTING_S390_ADAPTER 3 #define KVM_IRQ_ROUTING_HV_SINT 4 -No flags are specified so far, the corresponding field must be set to zero. +flags: +- KVM_MSI_VALID_DEVID: used along with KVM_IRQ_ROUTING_MSI + routing entry type, specifies that the devid field contains + a valid value. +- zero otherwise struct kvm_irq_routing_irqchip { __u32 irqchip; @@ -1479,9 +1483,20 @@ struct kvm_irq_routing_msi { __u32 address_lo; __u32 address_hi; __u32 data; - __u32 pad; + union { + __u32 pad; + __u32 devid; + }; }; +devid: If KVM_MSI_VALID_DEVID is set, contains a unique device identifier + for the device that wrote the MSI message. + For PCI, this is usually a BFD identifier in the lower 16 bits. + +The per-VM KVM_CAP_MSI_DEVID capability advertises the requirement to +provide the device ID. If this capability is not set, userland cannot +rely on the kernel to allow the KVM_MSI_VALID_DEVID flag being set. + struct kvm_irq_routing_s390_adapter { __u64 ind_addr; __u64 summary_addr; diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index d8c4c32..eb22208 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -879,7 +879,10 @@ struct kvm_irq_routing_msi { __u32 address_lo; __u32 address_hi; __u32 data; - __u32 pad; + union { + __u32 pad; + __u32 devid; + }; }; struct kvm_irq_routing_s390_adapter { -- 1.9.1