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| author | Johannes Berg <johannes.berg@intel.com> | 2021-03-05 13:19:58 +0100 |
|---|---|---|
| committer | Richard Weinberger <richard@nod.at> | 2021-06-17 21:45:43 +0200 |
| commit | 68f5d3f3b6543266b29e047cfaf9842333019b4c (patch) | |
| tree | 29590aaf2cbe0669962f23576c3a0b106327aba9 /arch/um/drivers/Kconfig | |
| parent | um: irqs: allow invoking time-travel handler multiple times (diff) | |
| download | linux-68f5d3f3b6543266b29e047cfaf9842333019b4c.tar.xz linux-68f5d3f3b6543266b29e047cfaf9842333019b4c.zip | |
um: add PCI over virtio emulation driver
To support testing of PCI/PCIe drivers in UML, add a PCI bus
support driver. This driver uses virtio, which in UML is really
just vhost-user, to talk to devices, and adds the devices to
the virtual PCI bus in the system.
Since virtio already allows DMA/bus mastering this really isn't
all that hard, of course we need the logic_iomem infrastructure
that was added by a previous patch.
The protocol to talk to the device is has a few fairly simple
messages for reading to/writing from config and IO spaces, and
messages for the device to send the various interrupts (INT#,
MSI/MSI-X and while suspended PME#).
Note that currently no offical virtio device ID is assigned for
this protocol, as a consequence this patch requires defining it
in the Kconfig, with a default that makes the driver refuse to
work at all.
Finally, in order to add support for MSI/MSI-X interrupts, some
small changes are needed in the UML IRQ code, it needs to have
more interrupts, changing NR_IRQS from 64 to 128 if this driver
is enabled, but not actually use them for anything so that the
generic IRQ domain/MSI infrastructure can allocate IRQ numbers.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Diffstat (limited to 'arch/um/drivers/Kconfig')
| -rw-r--r-- | arch/um/drivers/Kconfig | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/arch/um/drivers/Kconfig b/arch/um/drivers/Kconfig index 03ba34b61115..f145842c40b9 100644 --- a/arch/um/drivers/Kconfig +++ b/arch/um/drivers/Kconfig @@ -357,3 +357,23 @@ config UML_RTC rtcwake, especially in time-travel mode. This driver enables that by providing a fake RTC clock that causes a wakeup at the right time. + +config UML_PCI_OVER_VIRTIO + bool "Enable PCI over VIRTIO device simulation" + # in theory, just VIRTIO is enough, but that causes recursion + depends on VIRTIO_UML + select FORCE_PCI + select UML_IOMEM_EMULATION + select UML_DMA_EMULATION + select PCI_MSI + select PCI_MSI_IRQ_DOMAIN + select PCI_LOCKLESS_CONFIG + +config UML_PCI_OVER_VIRTIO_DEVICE_ID + int "set the virtio device ID for PCI emulation" + default -1 + depends on UML_PCI_OVER_VIRTIO + help + There's no official device ID assigned (yet), set the one you + wish to use for experimentation here. The default of -1 is + not valid and will cause the driver to fail at probe. |