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authorEric Auger <eric.auger@redhat.com>2016-07-22 19:20:37 +0300
committerMarc Zyngier <marc.zyngier@arm.com>2016-07-22 20:51:49 +0300
commit76a10b86785c5e3fc49bcee355502d035b07e47a (patch)
treee7f27dfa1b3c6c79a60eab55040be1745ce71903 /Documentation/virtual
parent3a88bded203591d4683aacdbb65cd0f549bc58cb (diff)
downloadlinux-76a10b86785c5e3fc49bcee355502d035b07e47a.tar.xz
KVM: api: Pass the devid in the msi routing entry
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 <eric.auger@redhat.com> Reviewed-by: Andre Przywara <andre.przywara@arm.com> Acked-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'Documentation/virtual')
-rw-r--r--Documentation/virtual/kvm/api.txt19
1 files changed, 17 insertions, 2 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 07049eadb124..415cde1647e9 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;