Before now, all the qemu hotplug functions assumed that all devices to
be hotplugged were legacy PCI endpoint devices
(VIR_PCI_CONNECT_TYPE_PCI_DEVICE). This worked out "okay", because all
devices *are* legacy PCI endpoint devices on x86/440fx machinetypes,
and hotplug didn't work properly on machinetypes using PCIe anyway
(hotplugging onto a legacy PCI slot doesn't work, and until commit
b87703cf any attempt to manually specify a PCIe address for a
hotplugged device would be erroneously rejected).

This patch makes all qemu hotplug operations honor the pciConnectFlags
set by the single all-knowing function
qemuDomainDeviceCalculatePCIConnectFlags(). This is done in 3 steps,
but in a single commit since we would have to touch the other points
at each step anyway:

1) add a flags argument to the hypervisor-agnostic
virDomainPCIAddressEnsureAddr() (previously it hardcoded
..._PCI_DEVICE)

2) add a new qemu-specific function qemuDomainEnsurePCIAddress() which
gets the correct pciConnectFlags for the device from
qemuDomainDeviceConnectFlags(), then calls
virDomainPCIAddressEnsureAddr().

3) in qemu_hotplug.c replace all calls to
virDomainPCIAddressEnsureAddr() with calls to
qemuDomainEnsurePCIAddress()

So in effect, we're putting a "shim" on top of all calls to
virDomainPCIAddressEnsureAddr() that sets the right pciConnectFlags.

When starting a new domain, we allocate the USB addresses and keep
an address cache in the domain object's private data.

However this data is lost on libvirtd restart.

Also generate the address cache if all the addresses have been
specified, so that devices hotplugged after libvirtd restart
also get theirs assigned.

https://bugzilla.redhat.com/show_bug.cgi?id=1387666

This time do not require an address cache as a parameter.

Simplify qemuDomainAttachChrDeviceAssignAddr to not generate
the virtio serial address cache for devices of other types.

Partially reverts commit 925fa4b9.

Commit 19a148b7 dropped the cache from QEMU's private domain object.
Assume the callers do not have the cache by default and use
a longer name for the internal ones that do.

This makes the shorter 'virDomainVirtioSerialAddrAutoAssign'
name availabe for a function that will not require the cache.

This function is no longer needed outside of domain_addr.c.

There is an existing virDomainPCIAddressReserveNextSlot() which will
reserve all functions of the next available PCI slot. One place in the
qemu PCI address assignment code requires reserving a *single*
function of the next available PCI slot. This patch modifies and
renames virDomainPCIAddressReserveNextSlot() so that it can fulfill
both the original purpose and the need to reserve a single function.

(This is being done so that the abovementioned code in qemu can have
its "kind of open coded" solution replaced with a call to this new
function).

A pci-bridge has *almost* the same rules as a legacy PCI endpoint
device for where it can be automatically connected, and until now both
had been considered identical. There is one pairing that is okay when
specifically requested by the user (i.e. manual assignment), but we
want to avoid it when auto-assigning addresses - plugging a pci-bridge
directly into pcie-root (it is cleaner to plug in a dmi-to-pci-bridge,
then plug the pci-bridge into that).

In order to allow that difference, this patch makes a separate
CONNECT_TYPE for pci-bridge, and uses it to restrict auto-assigned
addresses for pci-bridges to be only on pci-root, pci-expander-bus,
dmi-to-pci-bridge, or on another pci-bridge.

NB: As with other discouraged-but-seem-to-work configurations
(e.g. plugging a legacy PCI device into a pcie-root-port) if someone
*really* wants to, they can still force a pci-bridge to be plugged
into pcie-root (by manually specifying its PCI address.)

More misunderstanding/mistaken assumptions on my part - I had thought
that a pci-expander-bus could be plugged into any legacy PCI slot, and
that pcie-expander-bus could be plugged into any PCIe slot. This isn't
correct - they can both be plugged ontly into their respective root
buses. This patch adds that restriction.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1358712

libvirt had allowed a dmi-to-pci-bridge to be plugged in anywhere a
normal PCIe endpoint can be connected, but this is wrong - it will
only work if it's plugged into pcie-root (the PCIe root complex) or a
pcie-expander-bus (the qemu device pxb-pcie). This patch adjusts the
connection flags accordingly.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1363648

The address sets (pci, ccw, virtio serial) are currently cached
in qemu private data, but all the information required to recreate
these sets is in the domain definition. Therefore I am removing
the redundant data and adding a way to recalculate these sets.

Add a function that calculates the virtio serial address set
from the domain definition.

Credit goes to Cole Robinson.

When parsing a command line with USB devices that have
no address specified, QEMU automatically adds a USB hub
if the device would fill up all the available USB ports.

To help most of the users, add one hub if there are more
USB devices than available ports. For wilder configurations,
expect the user to provide us with more hubs and/or controllers.

USB disks, redirected devices, host devices and serial devices
are supported.

Automatically assign addresses to USB devices.

Just like reserving, this is only done for newly defined domains.

https://bugzilla.redhat.com/show_bug.cgi?id=1215968

Check if they fit on the USB controllers the domain has,
and error out if two devices try to use the same address.

Walk through all the usb controllers in the domain definition
and create the corresponding structures in the virDomainUSBAddressSet.

A new type to track USB addresses.

Every <controller type='usb' index='i'/> is represented by an
object of type virDomainUSBAddressHub located at buses[i].

Each of these hubs has up to 'nports' ports.
If a port is occupied, it has the corresponding bit set in
the 'ports' bitmap, e.g. port 1 would have the 0th bit set.
If there is a hub on this port, then hubs[i] will point
to this hub.

In preparation to tracking which USB addresses are occupied.
Introduce two helper functions for printing the port path
as a string and appending it to a virBuffer.

We had both and the only difference was that the latter also included
information about multifunction setting.  The problem with that was that
we couldn't use functions made for only one of the structs (e.g.
parsing).  To consolidate those two structs, use the one in virpci.h,
include that in domain_conf.h and add the multifunction member in it.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

There are two places in qemu_domain_address.c where we have a switch
statement to convert PCI controller models
(VIR_DOMAIN_CONTROLLER_MODEL_PCI*) into the connection type flag that
is matched when looking for an upstream connection for that model of
controller (VIR_PCI_CONNECT_TYPE_*). This patch makes a utility
function in conf/domain_addr.c to do that, so that when a new PCI
controller is added, we only need to add the new model-->connect-type
in a single place.

The flags used to determine which devices could be plugged into which
controllers were quite confusing, as they tried to create classes of
connections, then put particular devices into possibly multiple
classes, while sometimes setting multiple flags for the controllers
themselves. The attempt to have a single flag indicate, e.g. that a
root-port or a switch-downstream-port could connect was not only
confusing, it was leading to a situation where it would be impossible
to specify exactly the right combinations for a new controller.

The solution is for the VIR_PCI_CONNECT_TYPE_* flags to have a 1:1
correspondence with each type of PCI controller, plus a flag for a PCI
endpoint device and another for a PCIe endpoint device (the only
exception to this is that pci-bridge and pcie-expander-bus controllers
have their upstream connection classified as
VIR_PCI_CONNECT_TYPE_PCI_DEVICE since they can be plugged into
*exactly* the same ports as any endpoint device).  Each device then
has a single flag for connect type (plus the HOTPLUG flag if that
device can e hotplugged), and each controller sets the CONNECT bits
for all controllers that can be plugged into it, as well as for either
type of endpoint device that can be plugged in (and the HOTPLUG flag
if it can accept hotplugged devices).

With this change, it is *slightly* easier to understand the matching
of connections (as long as you remember that the flag for a
device/upstream-facing connection of a controller is the same as that
device's type, while the flags for a controller's downstream
connections is the OR of all device types that can be plugged into
that controller). More importantly, it will be possible to correctly
specify what can be plugged into a pcie-switch-expander-bus, when
support for it is added.

This function is no longer used outside domain_addr.c

We only support hotplugging SCSI controllers.
The USB and virtio-serial related code was never reachable because
this function was only called for VIR_DOMAIN_CONTROLLER_TYPE_SCSI
controllers.

This reverts commit ee0d97a7 and parts of commits 16db8d2e
and d6d54cd1.

This controller can be connected only to a pcie-root-port or a
pcie-switch-downstream-port (which will be added in a later patch),
which is the reason for the new connect type
VIR_PCI_CONNECT_TYPE_PCIE_PORT. A pcie-switch-upstream-port provides
32 ports (slot=0 to slot=31) on the downstream side, which can only
have pci controllers of model "pcie-switch-downstream-port" plugged
into them, which is the reason for the other new connect type
VIR_PCI_CONNECT_TYPE_PCIE_SWITCH.

This controller can be connected (at domain startup time only - not
hotpluggable) only to a port on the pcie root complex ("pcie-root" in
libvirt config), hence the new connect type
VIR_PCI_CONNECT_TYPE_PCIE_ROOT. It provides a hotpluggable port that
will accept any PCI or PCIe device.

New attributes must be added to the controller <target> subelement for
this - chassis and port are guest-visible option values that will be
set by libvirt with values derived from the controller's index and pci
address information.

When support for the pcie-root and dmi-to-pci-bridge buses on a Q35
machinetype was added, I was concerned that even though qemu at the
time allowed plugging a PCI device into a PCIe port, that it might not
be supported in the future. To prevent painful backtracking in the
possible future where this happened, I disallowed such connections
except in a few specific cases requested by qemu developers (indicated
in the code with the flag VIR_PCI_CONNECT_TYPE_EITHER_IF_CONFIG).

Now that a couple years have passed, there is a clear message from
qemu that there is no danger in allowing PCI devices to be plugged
into PCIe ports. This patch eliminates
VIR_PCI_CONNECT_TYPE_EITHER_IF_CONFIG and changes the code to always
allow PCI->PCIe or PCIe->PCI connection *when the PCI address is
specified in the config. (For newly added devices that haven't yet
been given a PCI address, the auto-placement still prefers using the
correct type of bus).

In virDomainVirtioSerialAddrNext, add another controller
if we've exhausted all ports of the existing controllers.

https://bugzilla.redhat.com/show_bug.cgi?id=1076708

Create a sorted array of virtio-serial controllers.
Each of the elements contains the controller index
and a bitmap of available ports.

Buses are not tracked, because they aren't supported by QEMU.

Just code movement and rename.

Move sharable PCI handling functions to domain_addr.[ch], and
change theirs prefix from 'qemu' to 'vir':

 - virDomainPCIAddressAsString;
 - virDomainPCIAddressBusSetModel;
 - virDomainPCIAddressEnsureAddr;
 - virDomainPCIAddressFlagsCompatible;
 - virDomainPCIAddressGetNextSlot;
 - virDomainPCIAddressReleaseSlot;
 - virDomainPCIAddressReserveAddr;
 - virDomainPCIAddressReserveNextSlot;
 - virDomainPCIAddressReserveSlot;
 - virDomainPCIAddressSetFree;
 - virDomainPCIAddressSetGrow;
 - virDomainPCIAddressSlotInUse;
 - virDomainPCIAddressValidate;

The only change here is function names, the implementation itself
stays untouched.

Extract common allocation code from DomainPCIAddressSetCreate
into virDomainPCIAddressSetAlloc.

Introduce new files (domain_addr.[ch]) to provide
an API for domain device handling that could be
shared across the drivers.

A list of data types were extracted and moved there:

 qemuDomainPCIAddressBus -> virDomainPCIAddressBus
 qemuDomainPCIAddressBusPtr -> virDomainPCIAddressBusPtr
 _qemuDomainPCIAddressSet -> virDomainPCIAddressSet
 qemuDomainPCIAddressSetPtr -> virDomainPCIAddressSetPtr
 qemuDomainPCIConnectFlags -> virDomainPCIConnectFlags

Also, move the related definitions and macros.