Another HPA suggestion: that the device be allowed to offer duplicate capabilities, particularly so it can offer a mem and an I/O bar and let the guest decide (Linux guest probably doesn't care?).
Cc: H. Peter Anvin <[email protected]> Signed-off-by: Rusty Russell <[email protected]> --- drivers/virtio/virtio_pci_legacy.c | 3 ++- include/linux/virtio_pci.h | 20 ++++++++++++++++---- 2 files changed, 18 insertions(+), 5 deletions(-) diff --git a/drivers/virtio/virtio_pci_legacy.c b/drivers/virtio/virtio_pci_legacy.c index 501fa79..c7aadcb 100644 --- a/drivers/virtio/virtio_pci_legacy.c +++ b/drivers/virtio/virtio_pci_legacy.c @@ -728,7 +728,8 @@ static int virtio_pci_probe(struct pci_dev *pci_dev, } /* We leave modern virtio-pci for the modern driver. */ - cap = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_COMMON_CFG); + cap = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_COMMON_CFG, + IORESOURCE_IO|IORESOURCE_MEM); if (cap) { if (force_nonlegacy) dev_info(&pci_dev->dev, diff --git a/include/linux/virtio_pci.h b/include/linux/virtio_pci.h index 2714160..6d2816b 100644 --- a/include/linux/virtio_pci.h +++ b/include/linux/virtio_pci.h @@ -4,18 +4,30 @@ #define VIRTIO_PCI_NO_LEGACY #include <uapi/linux/virtio_pci.h> -/* Returns offset of the capability, or 0. */ -static inline int virtio_pci_find_capability(struct pci_dev *dev, u8 cfg_type) +/** + * virtio_pci_find_capability - walk capabilities to find device info. + * @dev: the pci device + * @cfg_type: the VIRTIO_PCI_CAP_* value we seek + * @ioresource_types: IORESOURCE_MEM and/or IORESOURCE_IO. + * + * Returns offset of the capability, or 0. + */ +static inline int virtio_pci_find_capability(struct pci_dev *dev, u8 cfg_type, + u32 ioresource_types) { int pos; for (pos = pci_find_capability(dev, PCI_CAP_ID_VNDR); pos > 0; pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_VNDR)) { - u8 type; + u8 type, bar; pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap, cfg_type), &type); - if (type == cfg_type) + if (type != cfg_type) + continue; + pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap, + bar), &bar); + if (pci_resource_flags(dev, bar) & ioresource_types) return pos; } return 0; -- 1.7.10.4 _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
