[PATCH 1/7] KVM: api: add kvm_irq_routing_extended_msi
From: Pavel Fedin <hidden>
Date: 2015-07-02 07:26:43
Also in:
kvm, kvmarm, lkml
Hello!
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-----Original Message----- From: kvm-owner at vger.kernel.org [mailto:kvm-owner at vger.kernel.org] On Behalf Of Eric Auger Sent: Monday, June 29, 2015 6:37 PM To: eric.auger at st.com; eric.auger at linaro.org; linux-arm-kernel at lists.infradead.org; marc.zyngier at arm.com; christoffer.dall at linaro.org; andre.przywara at arm.com; kvmarm at lists.cs.columbia.edu; kvm at vger.kernel.org Cc: linux-kernel at vger.kernel.org; patches at linaro.org; p.fedin at samsung.com; pbonzini at redhat.com Subject: [PATCH 1/7] KVM: api: add kvm_irq_routing_extended_msi On ARM, the MSI msg (address and data) comes along with out-of-band device ID information. The device ID encodes the device that composes the MSI msg. Let's create a new routing entry type, dubbed KVM_IRQ_ROUTING_EXTENDED_MSI and use the __u32 pad space to convey the device ID. Signed-off-by: Eric Auger <redacted> --- RFC -> PATCH - remove kvm_irq_routing_extended_msi and use union instead --- Documentation/virtual/kvm/api.txt | 9 ++++++++- include/uapi/linux/kvm.h | 6 +++++- 2 files changed, 13 insertions(+), 2 deletions(-)diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index d20fd94..6426ae9 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt@@ -1414,7 +1414,10 @@ struct kvm_irq_routing_entry { __u32 gsi; __u32 type; __u32 flags; - __u32 pad; + union { + __u32 pad; + __u32 devid; + }; union { struct kvm_irq_routing_irqchip irqchip; struct kvm_irq_routing_msi msi;
devid is actually a part of MSI bunch. Shouldn't it be a part of struct kvm_irq_routing_msi then? It also has reserved pad.
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@@ -1427,6 +1430,10 @@ struct kvm_irq_routing_entry { #define KVM_IRQ_ROUTING_IRQCHIP 1 #define KVM_IRQ_ROUTING_MSI 2 #define KVM_IRQ_ROUTING_S390_ADAPTER 3 +#define KVM_IRQ_ROUTING_EXTENDED_MSI 4 + +In case of KVM_IRQ_ROUTING_EXTENDED_MSI routing type, devid is used to convey +the device ID. No flags are specified so far, the corresponding field must be set to zero.
What if we use KVM_MSI_VALID_DEVID flag instead of new KVM_IRQ_ROUTING_EXTENDED_MSI definition? I believe this would make an API more consistent and introduce less new definitions.
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diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 2a23705..8484681 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h@@ -841,12 +841,16 @@ struct kvm_irq_routing_s390_adapter { #define KVM_IRQ_ROUTING_IRQCHIP 1 #define KVM_IRQ_ROUTING_MSI 2 #define KVM_IRQ_ROUTING_S390_ADAPTER 3 +#define KVM_IRQ_ROUTING_EXTENDED_MSI 4 struct kvm_irq_routing_entry { __u32 gsi; __u32 type; __u32 flags; - __u32 pad; + union { + __u32 pad; + __u32 devid; + }; union { struct kvm_irq_routing_irqchip irqchip; struct kvm_irq_routing_msi msi; --1.9.1 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo at vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Kind regards, Pavel Fedin Expert Engineer Samsung Electronics Research center Russia