This patches are based on ppc-next, and can also be obtained from: https://github.com/mdroth/qemu/commits/spapr-pci-hotplug-r4-ppc-next
OVERVIEW These patches add support for PCI hotplug for SPAPR guests. We advertise each PHB as DR-capable (as defined by PAPR 13.5/13.6) with 32 hotpluggable PCI slots per PHB, which models a standard PCI expansion device for Power machines where the DRC name/loc-code/index for each slot are generated based on bus/slot number. This is compatible with existing guest kernel's via the rpaphp hotplug module, and existing userspace tools such as drmgr/librtas/rtas_errd for managing devices, in theory... NOTES / ADDITIONAL DEPENDENCIES Due to an issue with rpaphp, a workaround must be used for older guest kernels which relies on using bus rescan / remove sysfs interfaces instead of rpaphp-provided hotplug interfaces. Guest kernel fixes for rpaphp are in progress and available for testing here (there's still currently a benign issue with duplicate eeh sysfs entries with these, but the full guest-driven hotplug workflow is functional): https://github.com/mdroth/linux/commits/pci-hotplug-fixes Alternatively, there are updated userspace tools which add a "-v" option to drmgr to utilize bus rescan/remove instead of relying on rpaphp: https://github.com/tyreld/powerpc-utils/commits/hotplug It's possible to test guest-driven hotplug without either of these using a workaround (see USAGE below), but not recommended. PAPR does not currently define a mechanism for generating PCI hotplug/unplug events, and relies on guest-driven management of devices, so as part of this series we also introduce an extension to the existing EPOW power event reporting mechanism (where a guest will query for events via check-exception RTAS calls in response to an external interrupt) to surface hotplug/unplug events with the information needed to manage the devices automatically via the rtas_errd guest service. In order to enable this qemu-driven hotplug/unplug workflow (for parity with ACPI/SHPC-based guests), updated versions of librtas/ppc64-diag are required, which are available here: https://github.com/tyreld/ppc64-diag/commits/hotplug https://github.com/tyreld/librtas/commits/hotplug Lacking those, users must manage device hotplug/unplug manually. Additionally, PAPR requires the presence of additional OF properties (ibm,my-drc-index and loc-code) for hotpluggable slots that have already been populated at the time of boot to support unplug, so an updated SLOF is required to allow for device unplug after a guest reboot. (these properties cannot currently be added to boot-time FDT, since they will conflict with SLOF-generated device nodes, so we either need to teach SLOF to re-use/merge existing entries, or simply have it generate the required properties values for board-qemu, which is the approach taken here). A patch for SLOF is available below, along with a pre-built SLOF binary which includes it (for testing): https://github.com/mdroth/SLOF/commit/2e09a2950db0ce8ed464b80cccfea56dccf85d66 https://github.com/mdroth/qemu/blob/19a390e3270a7defc7158ce29e52ff2b27d666ae/pc-bios/slof.bin PATCH LAYOUT Patches 1-4 add RTAS interfaces required for device configuration 5-6 advertise PHBs and associated slots as hotpluggable to guests 8-10 add helpers and a possible fix for BAR-assignment handling 11 enables device_add/device_del for spapr machines and guest-driven hotplug 12-14 define hotplug event structure and emit them in response to device_add/device_del USAGE With unmodified guests: hotplug: qemu: device_add e1000,id=slot0 guest: drmgr -c pci -s "Slot 0" -n -a echo 1 >/sys/bus/pci/rescan unplug: guest: drmgr -c pci -s "Slot 0" -n -r echo 1 >/sys/bus/pci/devices/0000:00:00.0/remove qemu: device_del slot0 With only updated guest kernel: hotplug: qemu: device_add e1000,id=slot0 guest: modprobe rpaphp drmgr -c pci -s "Slot 0" -n -a unplug: guest: drmgr -c pci -s "Slot 0" -n -r qemu: device_del slot0 With only updated powerpc-utils/drmgr: hotplug: qemu: device_add e1000,id=slot0 guest: drmgr -c pci -s "Slot 0" -n -v -a unplug: guest: drmgr -c pci -s "Slot 0" -n -v -r qemu: device_del slot0 With updated librtas/ppc64-diag and either an updated guest kernel or drmgr: hotplug: qemu: device_add e1000,id=slot0 unplug: qemu: device_del slot0 hw/pci/pci.c | 5 +- hw/ppc/spapr.c | 174 +++++++++- hw/ppc/spapr_events.c | 228 ++++++++++--- hw/ppc/spapr_pci.c | 768 ++++++++++++++++++++++++++++++++++++++++++- include/exec/memory.h | 34 ++ include/hw/pci-host/spapr.h | 1 + include/hw/pci/pci.h | 1 + include/hw/ppc/spapr.h | 77 ++++- memory.c | 50 +++ 9 files changed, 1286 insertions(+), 52 deletions(-)
