We have agreed that OpenFirmware device paths in the "bootorder" fw_cfg
file should follow the pattern
/pci@i0cf8,%x/...
for devices that live behind an extra root bus. The extra root bus in
question is the %x'th among the extra root buses. (In other words, %x
gives the position of the affected extra root bus relative to the other
extra root buses, in bus_nr order.) %x starts at 1, and is formatted in
hex.
The portion of the unit address that comes before the comma is dynamically
taken from the main host bridge, similarly to sysbus_get_fw_dev_path().
Cc: Kevin O'Connor <kevin@koconnor.net>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Marcel Apfelbaum <marcel@redhat.com>
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
OVMF downloads the ACPI linker/loader script from QEMU when the edk2 PCI
Bus driver globally signals the firmware that PCI enumeration and resource
allocation have completed. At this point QEMU regenerates the ACPI payload
in an fw_cfg read callback, and this is when the PXB's _CRS gets
populated.
Unfortunately, when this happens, the PCI_COMMAND_MEMORY bit is clear in
the root bus's command register, *unlike* under SeaBIOS. The consequences
unfold as follows:
- When build_crs() fetches dev->io_regions[i].addr, it is all-bits-one,
because pci_update_mappings() --> pci_bar_address() calculated it as
PCI_BAR_UNMAPPED, due to the PCI_COMMAND_MEMORY bit being clear.
- Consequently, the SHPC MMIO BAR (bar 0) of the bridge is not added to
the _CRS, *despite* having been programmed in PCI config space.
- Similarly, the SHPC MMIO BAR of the PXB is not removed from the main
root bus's DWordMemory descriptor.
- Guest OSes (Linux and Windows alike) notice the pre-programmed SHPC BAR
within the PXB's config space, and notice that it conflicts with the
main root bus's memory resource descriptors. Linux reports
pci 0000:04:00.0: BAR 0: can't assign mem (size 0x100)
pci 0000:04:00.0: BAR 0: trying firmware assignment [mem
0x88200000-0x882000ff 64bit]
pci 0000:04:00.0: BAR 0: [mem 0x88200000-0x882000ff 64bit] conflicts
with PCI Bus 0000:00 [mem
0x88200000-0xfebfffff]
While Windows Server 2012 R2 reports
https://technet.microsoft.com/en-us/library/cc732199%28v=ws.10%29.aspx
This device cannot find enough free resources that it can use. If you
want to use this device, you will need to disable one of the other
devices on this system. (Code 12)
This issue was apparently encountered earlier, see the "hack" in:
https://lists.nongnu.org/archive/html/qemu-devel/2015-01/msg02983.html
and the current hole-punching logic in build_crs() and build_ssdt() is
probably supposed to remedy exactly that problem -- however, for OVMF they
don't work, because at the end of the PCI enumeration and resource
allocation, which cues the ACPI linker/loader client, the command register
is clear.
The "shpc" property of "pci-bridge", introduced in the previous patches,
allows us to disable the standard hotplug controller cleanly, eliminating
the SHPC bar and the conflict.
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Marcel Apfelbaum <marcel@redhat.com>
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This should help catch property name typos at compile time.
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Marcel Apfelbaum <marcel@redhat.com>
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The pxb can be attach to and existing numa node by specifying
numa_node option that equals the desired numa nodeid.
Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
The bios does not index the pxb slot number when
it computes the IRQ because it resides on bus 0
and not on the current bus.
However Qemu routes the irq through bus 0 and adds
the pxb slot to the IRQ computation of the PXB device.
Synchronize between bios and Qemu by canceling
pxb's effect.
Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
PXB is a "light-weight" host bridge whose purpose is to enable
the main host bridge to support multiple PCI root buses
for pc machines.
As oposed to PCI-2-PCI bridge's secondary bus, PXB's bus
is a primary bus and can be associated with a NUMA node
(different from the main host bridge) allowing the guest OS
to recognize the proximity of a pass-through device to
other resources as RAM and CPUs.
The PXB is composed from:
- A primary PCI bus (can be associated with a NUMA node)
Acts like a normal pci bus and from the functionality point
of view is an "expansion" of the bus behind the
main host bridge.
- A pci-2-pci bridge behind the primary PCI bus where the actual
devices will be attached.
- A host-bridge PCI device
Situated on the bus behind the main host bridge, allows
the BIOS to configure the bus number and IO/mem resources.
It does not have its own config/data register for configuration
cycles, this being handled by the main host bridge.
- A host-bridge sysbus to comply with QEMU current design.
Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Laszlo Ersek
Marcel Apfelbaum
Marcel Apfelbaum