KVM: Extend struct kvm_msi to hold a 32-bit device ID (2b8ddd93) · Commits · 戴 / test

The ARM GICv3 ITS MSI controller requires a device ID to be able to assign the proper interrupt vector. On real hardware, this ID is sampled from the bus. To be able to emulate an ITS controller, extend the KVM MSI interface to let userspace provide such a device ID. For PCI devices, the device ID is simply the 16-bit bus-device-function triplet, which should be easily available to the userland tool. Also there is a new KVM capability which advertises whether the current VM requires a device ID to be set along with the MSI data. This flag is still reported as not available everywhere, later we will enable it when ITS emulation is used. Signed-off-by:

Andre Przywara <andre.przywara@arm.com> Reviewed-by:

Eric Auger <eric.auger@linaro.org> Reviewed-by:

Marc Zyngier <marc.zyngier@arm.com> Acked-by:

Christoffer Dall <christoffer.dall@linaro.org> Acked-by:

Paolo Bonzini <pbonzini@redhat.com> Tested-by:

Eric Auger <eric.auger@redhat.com> Signed-off-by:

Marc Zyngier <marc.zyngier@arm.com>

Documentation/virtual/kvm/api.txt

+10 −2

Original line number	Diff line number	Diff line
		@@ -2175,10 +2175,18 @@ struct kvm_msi {
		__u32 address_hi;
		__u32 data;
		__u32 flags;
		__u8 pad[16];
		__u32 devid;
		__u8 pad[12];
		};

		No flags are defined so far. The corresponding field must be 0.
		flags: KVM_MSI_VALID_DEVID: devid contains a valid value
		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.


		4.71 KVM_CREATE_PIT2

include/uapi/linux/kvm.h

+4 −1

Original line number	Diff line number	Diff line
		@@ -866,6 +866,7 @@ struct kvm_ppc_smmu_info {
		#define KVM_CAP_ARM_PMU_V3 126
		#define KVM_CAP_VCPU_ATTRIBUTES 127
		#define KVM_CAP_MAX_VCPU_ID 128
		#define KVM_CAP_MSI_DEVID 129

		#ifdef KVM_CAP_IRQ_ROUTING

		@@ -1024,12 +1025,14 @@ struct kvm_one_reg {
		__u64 addr;
		};

		#define KVM_MSI_VALID_DEVID (1U << 0)
		struct kvm_msi {
		__u32 address_lo;
		__u32 address_hi;
		__u32 data;
		__u32 flags;
		__u8 pad[16];
		__u32 devid;
		__u8 pad[12];
		};

		struct kvm_arm_device_addr {

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