With module option to override. I assume I can call
pci_find_capability() before pci_request_regions?
---
drivers/virtio/virtio_pci_legacy.c | 20 +++++++++++++++++++-
include/linux/virtio_pci.h | 19 +++++++++++++++++++
2 files changed, 38 insertions(+), 1 deletion(-)
diff --git a/drivers/virtio/virtio_pci_legacy.c
b/drivers/virtio/virtio_pci_legacy.c
--- a/drivers/virtio/virtio_pci_legacy.c
+++ b/drivers/virtio/virtio_pci_legacy.c
@@ -26,6 +26,10 @@
#include <linux/highmem.h>
#include <linux/spinlock.h>
+static bool force_nonlegacy;
+module_param(force_nonlegacy, bool, 0644);
+MODULE_PARM_DESC(force_nonlegacy, "Take over non-legacy virtio devices too");
+
MODULE_AUTHOR("Anthony Liguori <[email protected]>");
MODULE_DESCRIPTION("virtio-pci-legacy");
MODULE_LICENSE("GPL");
@@ -622,7 +626,7 @@ static int __devinit virtio_pci_probe(st
const struct pci_device_id *id)
{
struct virtio_pci_device *vp_dev;
- int err;
+ int err, cap;
/* We only own devices >= 0x1000 and <= 0x103f: leave the rest. */
if (pci_dev->device < 0x1000 || pci_dev->device > 0x103f)
@@ -654,6 +658,21 @@ static int __devinit virtio_pci_probe(st
if (err)
goto out;
+ /* We leave modern virtio-pci for the modern driver. */
+ cap = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_COMMON_CFG);
+ if (cap) {
+ if (force_nonlegacy)
+ dev_info(&pci_dev->dev,
+ "virtio_pci_legacy: forcing legacy mode!\n");
+ else {
+ dev_info(&pci_dev->dev,
+ "virtio_pci_legacy: leaving to"
+ " non-legacy driver\n");
+ err = -ENODEV;
+ goto out_enable_device;
+ }
+ }
+
err = pci_request_regions(pci_dev, "virtio-pci-legacy");
if (err)
goto out_enable_device;
diff --git a/include/linux/virtio_pci.h b/include/linux/virtio_pci.h
--- a/include/linux/virtio_pci.h
+++ b/include/linux/virtio_pci.h
@@ -152,4 +152,23 @@ struct virtio_pci_common_cfg {
__le16 queue_msix_vector;/* read-write */
__le64 queue_address; /* read-write: 0xFFFFFFFFFFFFFFFF == DNE. */
};
+
+#ifdef __KERNEL__
+/* Returns offset of the capability, or 0. */
+static inline int virtio_pci_find_capability(struct pci_dev *dev, u8 cfg_type)
+{
+ 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;
+ pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
+ cfg_type), &type);
+ if (type == cfg_type)
+ return pos;
+ }
+ return 0;
+}
+#endif /* __KERNEL__ */
#endif
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