[PATCH v3 1/7] KVM: api: pass the devid in the msi routing entry
From: Eric Auger <hidden>
Date: 2015-08-03 15:32:24
Also in:
kvm, kvmarm, lkml
Subsystem:
documentation, kernel virtual machine (kvm), the rest · Maintainers:
Jonathan Corbet, Paolo Bonzini, Linus Torvalds
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 <redacted> --- 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 | 18 ++++++++++++++++-- include/uapi/linux/kvm.h | 5 ++++- 2 files changed, 20 insertions(+), 3 deletions(-)
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 1b53155..d4b29df 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt@@ -1454,7 +1454,10 @@ struct kvm_irq_routing_entry { #define KVM_IRQ_ROUTING_MSI 2 #define KVM_IRQ_ROUTING_S390_ADAPTER 3 -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, it tells the msi devid contains a valid value. +- zero otherwise struct kvm_irq_routing_irqchip { __u32 irqchip;
@@ -1465,9 +1468,20 @@ 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 need 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 1c48def..3c865b9 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h@@ -830,7 +830,10 @@ 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