[libvirt] [PATCH 0/8] aggregate multiple pcie-root-ports onto a single slot
These patches implement a reccomendation from Gerd Hoffman during
discussion of Marcel Apfelbaum's proposed "PCIe devices placement
guidelines" document on qemu-devel:
https://lists.gnu.org/archive/html/qemu-devel/2016-09/msg01381.html
The basic idea is to put up to 8 pcie-root-ports on each slot of
pcie-root, rather than libvirt's historical practice of assigning only
a single device to each slot.
This is done by defining a new pciConnectFlag -
VIR_PCI_CONNECT_AGGREGATE_SLOT - which is set for any device that can
be automatically placed together with other similarly flagged devices
on multiple functions of the same slot. In this way we can
auto-address up to 224 hotpluggable PCIe devices without needing to
figure out how to automatically add upstream/downstream ports.
Other types of devices could be given the same treatment, although it
would make no sense for anything that you wanted to be hotplugable.
In order for this all to work nicely and make sense, the PCI address
reservation code has eliminated the "reserveEntireSlot" concept - if
the first device assigned to a particular slot doesn't have the
AGGREGATE_SLOT flag set, then it will be the only device allowed on
that slot even though the address set only shows function 0 as being
in use.
After all of this change, using the term "Slot" in so many function
names no longer makes sense; there is another patchset that I will
post shortly that gets rid of all that "old inaccurate" naming. I made
it separate because it isn't strictly necessary for the AGGREGATE_SLOT
functionality.
This series needs to be applied on top of my earlier series that adds
support for plugging virtio devices into PCIe slots.
Laine Stump (8):
conf: use struct instead of int for each slot in
virDomainPCIAddressBus
conf: eliminate concept of "reserveEntireSlot"
conf: eliminate repetitive code in virDomainPCIAddressGetNextSlot()
conf: start search for next unused PCI address at same slot as
previous find
conf: new function virDomainPCIAddressIsMulti()
qemu: use virDomainPCIAddressIsMulti() to determine multifunction
setting
conf: aggregate multiple devices on a slot when assigning PCI
addresses
conf: aggregate multiple pcie-root-ports onto a single slot
src/conf/domain_addr.c | 290 ++++++++++++++-------
src/conf/domain_addr.h | 48 +++-
src/libvirt_private.syms | 1 +
src/qemu/qemu_command.c | 16 +-
src/qemu/qemu_domain_address.c | 35 ++-
.../qemuxml2argv-pcie-root-port.args | 5 +-
.../qemuxml2argv-pcie-switch-upstream-port.args | 5 +-
.../qemuxml2argv-q35-default-devices-only.args | 7 +-
.../qemuxml2argv-q35-multifunction.args | 43 +++
.../qemuxml2argv-q35-multifunction.xml | 51 ++++
.../qemuxml2argv-q35-pcie-autoadd.args | 30 ++-
tests/qemuxml2argvdata/qemuxml2argv-q35-pcie.args | 28 +-
.../qemuxml2argv-q35-virt-manager-basic.args | 13 +-
.../qemuxml2argv-q35-virtio-pci.args | 28 +-
tests/qemuxml2argvtest.c | 25 ++
.../qemuxml2xmlout-pcie-root-port.xml | 2 +-
.../qemuxml2xmlout-pcie-switch-upstream-port.xml | 4 +-
.../qemuxml2xmlout-q35-default-devices-only.xml | 8 +-
.../qemuxml2xmlout-q35-multifunction.xml | 120 +++++++++
.../qemuxml2xmlout-q35-pcie-autoadd.xml | 52 ++--
.../qemuxml2xmloutdata/qemuxml2xmlout-q35-pcie.xml | 48 ++--
.../qemuxml2xmlout-q35-virt-manager-basic.xml | 20 +-
.../qemuxml2xmlout-q35-virtio-pci.xml | 48 ++--
tests/qemuxml2xmltest.c | 25 ++
24 files changed, 676 insertions(+), 276 deletions(-)
create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-q35-multifunction.args
create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-q35-multifunction.xml
create mode 100644 tests/qemuxml2xmloutdata/qemuxml2xmlout-q35-multifunction.xml
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2.7.4