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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/Kconfig | |
| parent | a5ab7c8467f1934236e33d5fa1c3c6de831a6648 (diff) | |
| download | linux-68f5d3f3b6543266b29e047cfaf9842333019b4c.tar.gz | |
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/Kconfig')
| -rw-r--r-- | arch/um/Kconfig | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/arch/um/Kconfig b/arch/um/Kconfig index e72b4b393367..328ba973c07d 100644 --- a/arch/um/Kconfig +++ b/arch/um/Kconfig @@ -15,7 +15,7 @@ config UML select HAVE_FUTEX_CMPXCHG if FUTEX select HAVE_DEBUG_KMEMLEAK select HAVE_DEBUG_BUGVERBOSE - select NO_DMA + select NO_DMA if !UML_DMA_EMULATION select GENERIC_IRQ_SHOW select GENERIC_CPU_DEVICES select HAVE_GCC_PLUGINS @@ -26,10 +26,21 @@ config MMU bool default y +config UML_DMA_EMULATION + bool + config NO_IOMEM bool "disable IOMEM" if EXPERT + depends on !INDIRECT_IOMEM default y +config UML_IOMEM_EMULATION + bool + select INDIRECT_IOMEM + select GENERIC_PCI_IOMAP + select GENERIC_IOMAP + select NO_GENERIC_PCI_IOPORT_MAP + config NO_IOPORT_MAP def_bool y |