From 82af8ce84ed65d2fb6d8c017d3f2bbbf161061fb Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Thu, 14 May 2009 13:55:41 +0300 Subject: virtio_pci: optional MSI-X support This implements optional MSI-X support in virtio_pci. MSI-X is used whenever the host supports at least 2 MSI-X vectors: 1 for configuration changes and 1 for virtqueues. Per-virtqueue vectors are allocated if enough vectors available. Signed-off-by: Michael S. Tsirkin Acked-by: Anthony Liguori Signed-off-by: Rusty Russell (+ whitespace, style) --- include/linux/virtio_pci.h | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/virtio_pci.h b/include/linux/virtio_pci.h index cd0fd5d181a..9a3d7c48c62 100644 --- a/include/linux/virtio_pci.h +++ b/include/linux/virtio_pci.h @@ -47,9 +47,17 @@ /* The bit of the ISR which indicates a device configuration change. */ #define VIRTIO_PCI_ISR_CONFIG 0x2 +/* MSI-X registers: only enabled if MSI-X is enabled. */ +/* A 16-bit vector for configuration changes. */ +#define VIRTIO_MSI_CONFIG_VECTOR 20 +/* A 16-bit vector for selected queue notifications. */ +#define VIRTIO_MSI_QUEUE_VECTOR 22 +/* Vector value used to disable MSI for queue */ +#define VIRTIO_MSI_NO_VECTOR 0xffff + /* The remaining space is defined by each driver as the per-driver * configuration space */ -#define VIRTIO_PCI_CONFIG 20 +#define VIRTIO_PCI_CONFIG(dev) ((dev)->msix_enabled ? 24 : 20) /* Virtio ABI version, this must match exactly */ #define VIRTIO_PCI_ABI_VERSION 0 -- cgit v1.2.3