[kvmtool PATCH v9 14/15] extend GSI IRQ routing to take a device ID

[Marc Zyngier]

On 02/02/17 16:32, Andre Przywara wrote:
> For ITS emulation we need the device ID along with the MSI payload
> and doorbell address to identify an MSI, so we need to put it in the
> GSI IRQ routing table too.
> There is a per-VM capability by which the kernel signals the need for
> a device ID, so check this and put the device ID into the routing
> table if needed.
> For PCI devices we take the bus/device/function triplet and and that
> to the routing setup call.
> 
> Signed-off-by: Andre Przywara <andre.przywara at arm.com>
> ---
>  hw/pci-shmem.c    |  3 ++-
>  include/kvm/irq.h |  2 +-
>  irq.c             | 24 ++++++++++++++++++++++--
>  virtio/pci.c      |  6 ++++--
>  4 files changed, 29 insertions(+), 6 deletions(-)
> 
> diff --git a/hw/pci-shmem.c b/hw/pci-shmem.c
> index 7ce98cb..512b5b0 100644
> --- a/hw/pci-shmem.c
> +++ b/hw/pci-shmem.c
> @@ -135,7 +135,8 @@ int pci_shmem__get_local_irqfd(struct kvm *kvm)
>  			return fd;
>  
>  		if (pci_shmem_pci_device.msix.ctrl & cpu_to_le16(PCI_MSIX_FLAGS_ENABLE)) {
> -			gsi = irq__add_msix_route(kvm, &msix_table[0].msg);
> +			gsi = irq__add_msix_route(kvm, &msix_table[0].msg,
> +						  pci_shmem_device.dev_num << 3);
>  			if (gsi < 0)
>  				return gsi;
>  		} else {
> diff --git a/include/kvm/irq.h b/include/kvm/irq.h
> index f35eb7e..ee059e3 100644
> --- a/include/kvm/irq.h
> +++ b/include/kvm/irq.h
> @@ -20,7 +20,7 @@ int irq__init(struct kvm *kvm);
>  int irq__exit(struct kvm *kvm);
>  
>  int irq__allocate_routing_entry(void);
> -int irq__add_msix_route(struct kvm *kvm, struct msi_msg *msg);
> +int irq__add_msix_route(struct kvm *kvm, struct msi_msg *msg, u32 device_id);
>  void irq__update_msix_route(struct kvm *kvm, u32 gsi, struct msi_msg *msg);
>  
>  #endif
> diff --git a/irq.c b/irq.c
> index 6ec71c3..9ca6b19 100644
> --- a/irq.c
> +++ b/irq.c
> @@ -66,7 +66,21 @@ static bool check_for_irq_routing(struct kvm *kvm)
>  	return has_irq_routing > 0;
>  }
>  
> -int irq__add_msix_route(struct kvm *kvm, struct msi_msg *msg)
> +static bool check_for_msi_devid(struct kvm *kvm)
> +{
> +	static int needs_devid = 0;
> +
> +	if (needs_devid == 0) {
> +		if (kvm__supports_vm_extension(kvm, KVM_CAP_MSI_DEVID))
> +			needs_devid = 1;
> +		else
> +			needs_devid = -1;
> +	}

Same remark as the previous patch. Except that you don't have a PCI
device directly here. Just store the flag in the kvm structure instead
by probing at startup time? Or even by setting that flag altogether if
you instantiate an ITS?

> +
> +	return needs_devid > 0;
> +}
> +
> +int irq__add_msix_route(struct kvm *kvm, struct msi_msg *msg, u32 device_id)
>  {
>  	int r;
>  
> @@ -77,7 +91,7 @@ int irq__add_msix_route(struct kvm *kvm, struct msi_msg *msg)
>  	if (r)
>  		return r;
>  
> -	irq_routing->entries[irq_routing->nr++] =
> +	irq_routing->entries[irq_routing->nr] =
>  		(struct kvm_irq_routing_entry) {
>  			.gsi = next_gsi,
>  			.type = KVM_IRQ_ROUTING_MSI,
> @@ -86,6 +100,12 @@ int irq__add_msix_route(struct kvm *kvm, struct msi_msg *msg)
>  			.u.msi.data = msg->data,
>  		};
>  
> +	if (check_for_msi_devid(kvm)) {
> +		irq_routing->entries[irq_routing->nr].flags = KVM_MSI_VALID_DEVID;
> +		irq_routing->entries[irq_routing->nr].u.msi.devid = device_id;
> +	}
> +	irq_routing->nr++;
> +
>  	r = ioctl(kvm->vm_fd, KVM_SET_GSI_ROUTING, irq_routing);
>  	if (r)
>  		return r;
> diff --git a/virtio/pci.c b/virtio/pci.c
> index cecfe8a..b6ef389 100644
> --- a/virtio/pci.c
> +++ b/virtio/pci.c
> @@ -192,7 +192,8 @@ static bool virtio_pci__specific_io_out(struct kvm *kvm, struct virtio_device *v
>  				break;
>  
>  			gsi = irq__add_msix_route(kvm,
> -						  &vpci->msix_table[vec].msg);
> +						  &vpci->msix_table[vec].msg,
> +						  vpci->dev_hdr.dev_num << 3);
>  			if (gsi >= 0) {
>  				vpci->config_gsi = gsi;
>  				break;
> @@ -210,7 +211,8 @@ static bool virtio_pci__specific_io_out(struct kvm *kvm, struct virtio_device *v
>  				break;
>  
>  			gsi = irq__add_msix_route(kvm,
> -						  &vpci->msix_table[vec].msg);
> +						  &vpci->msix_table[vec].msg,
> +						  vpci->dev_hdr.dev_num << 3);
>  			if (gsi < 0) {
>  				if (gsi == -ENXIO &&
>  				    vpci->features & VIRTIO_PCI_F_SIGNAL_MSI)
> 

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...