With module option to override.
Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
---
drivers/virtio/virtio_pci_legacy.c | 20 +++++++++++++++++++-
include/linux/virtio_pci.h | 16 ++++++++++++++++
2 files changed, 35 insertions(+), 1 deletion(-)
diff --git a/drivers/virtio/virtio_pci_legacy.c b/drivers/virtio/virtio_pci_legacy.c
index c75eb39..501fa79 100644
--- 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 <aliguori@xxxxxxxxxx>");
MODULE_DESCRIPTION("virtio-pci-legacy");
MODULE_LICENSE("GPL");
@@ -711,7 +715,7 @@ static int virtio_pci_probe(struct pci_dev *pci_dev,
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)
@@ -723,6 +727,20 @@ static int virtio_pci_probe(struct pci_dev *pci_dev,
return -ENODEV;
}
+ /* 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");
+ return -ENODEV;
+ }
+ }
+
/* allocate our structure and fill it out */
vp_dev = kzalloc(sizeof(struct virtio_pci_device), GFP_KERNEL);
if (vp_dev == NULL)
diff --git a/include/linux/virtio_pci.h b/include/linux/virtio_pci.h
index af5b9ab..2714160 100644
--- a/include/linux/virtio_pci.h
+++ b/include/linux/virtio_pci.h
@@ -4,4 +4,20 @@
#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)
+{
+ 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 /* _LINUX_VIRTIO_PCI_H */
--
1.7.10.4
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