virtio_mmio: Delete a stale #if 0'ed debug print

This was blindly moved in r360722 but the variable being printed is not
yet initialised. It's of little use and can easily be added back in the
right

virtio_mmio: Delete a stale #if 0'ed debug print

This was blindly moved in r360722 but the variable being printed is not
yet initialised. It's of little use and can easily be added back in the
right place if needed by someone debugging, so just delete it.

Reported by: bryanv

show more ...

virtio_mmio: Fix V1 device probing spec conformance (section 4.2.3.1.1)

We must check MagicValue not just Version before anything else, and then
we must check DeviceID and immediately abort if zero

virtio_mmio: Fix V1 device probing spec conformance (section 4.2.3.1.1)

We must check MagicValue not just Version before anything else, and then
we must check DeviceID and immediately abort if zero (and this must not
be an error).

Do all this when probing rather than at the start of attaching as that's
where this belongs, and provides a clear boundary between the device
detection and device initialisation parts of the specified driver
initialisation process. This also means we don't create empty device
instances for placeholder devices, reducing clutter on systems that
pre-allocate a large number, such as QEMU's AArch64 virt machine (which
provides 32).

Reviewed by: bryanv
Differential Revision: https://reviews.freebsd.org/D28070

show more ...

virtio_mmio: Fix a style(9) issue

virtio: Add VirtIO PCI modern (V1) support

Use the existing legacy PCI driver as the basis for shared code
between the legacy and modern PCI drivers. The existing virtio_pci
kernel module will conta

virtio: Add VirtIO PCI modern (V1) support

Use the existing legacy PCI driver as the basis for shared code
between the legacy and modern PCI drivers. The existing virtio_pci
kernel module will contain both the legacy and modern drivers.

Changes to the virtqueue and each device driver (network, block, etc)
for V1 support come in later commits.

Update the MMIO driver to reflect the VirtIO bus method changes, but
the modern compliance can be improved on later.

Note that the modern PCI driver requires bus_map_resource() to be
implemented, which is not the case on all archs.

The hw.virtio.pci.transitional tunable default value is zero so
transitional devices will continue to be driven via the legacy
driver.

Reviewed by: grehan (mentor)
Differential Revision: https://reviews.freebsd.org/D27856

show more ...