These rules will make it possible for libvirt to
automatically assign PCI addresses in a way that
respects any isolation constraints devices might
have.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Laine Stump <laine@laine.org>
Isolation groups will eventually allow us to make sure certain
devices, eg. PCI hostdevs, are assigned to guest PCI buses in
a way that guarantees improved isolation, error detection and
recovery for machine types and hypervisors that support it,
eg. pSeries guest on QEMU.
This patch merely defines storage for the new information
we're going to need later on and makes sure it is passed from
the hypervisor driver (QEMU / bhyve) down to the generic PCI
address allocation code.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Laine Stump <laine@laine.org>
When looking for slots suitable for a PCI device, libvirt
might need to add an extra PCI controller: for pSeries guests,
we want that extra controller to be a PHB (pci-root) rather
than a PCI bridge.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Laine Stump <laine@laine.org>
The current algorithm for slot allocation tries to be clever
and avoid looking at buses / slots more than once unless it's
necessary. Unfortunately that makes the code more complex,
and it will cause problem later on in some situations unless
even more complex code is added.
Since the performance gains are going to be pretty modest
anyway, we can just get rid of the extra complexity and use a
completely straighforward implementation instead.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Laine Stump <laine@laine.org>
Move @function after @flags to match other functions in the
same module like virDomainPCIAddressReserveNextAddr().
Also move virDomainPCIAddressReserveNextAddr() closer to
virDomainPCIAddressReserveAddr() in the header file.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Laine Stump <laine@laine.org>
This function was private to the QEMU driver and was,
accordingly, called qemuDomainPCIBusFullyReserved().
However the function is really not QEMU-specific at
all, so it makes sense to move it closer to the
virDomainPCIAddressBus struct it operates on.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Laine Stump <laine@laine.org>
When switching over the values in the virDomainControllerModelPCI
enumeration, make sure the proper cast is in place so that the
compiler can warn us when the coverage is not exaustive.
For the same reason, remove the 'default' case from one of the
existing switch statements.
The switch in virDomainPCIControllerModelToConnectType()
had some code that, while techically part of the
_PCIE_SWITCH_DOWNSTREAM_PORT case, was in fact dead due
to the early return.
Get rid of the dead code, and fix the inaccurate function
description while at it.
Move the range check introduced by commit 2650d5e into
virDomainUSBAddressFindPort. That way both virDomainUSBAddressRelease
and virDomainUSBAddressSetAddHub can benefit from it.
Reported-by: Michal Privoznik <mprivozn@redhat.com>
Surprisingly there was a virDomainPCIAddressReleaseAddr() function
already, but it was completely unused. Since we don't reserve entire
slots at once any more, there is no need to release entire slots
either, so we just replace the single call to
virDomainPCIAddressReleaseSlot() with a call to
virDomainPCIAddressReleaseAddr() and remove the now unused function.
The keen observer may be concerned that ...Addr() doesn't call
virDomainPCIAddressValidate(), as ...Slot() did. But really the
validation was pointless anyway - if the device hadn't been suitable
to be connected at that address, it would have failed validation
before every being reserved in the first place, so by definition it
will pass validation when it is being unplugged. (And anyway, even if
something "bad" happened and we managed to have a device incorrectly
at the given address, we would still want to be able to free it up for
use by a device that *did* validate properly).
This is in preparation for renaming virDomainPCIAddressReserveSlot()
to virDomainPCIAddressReserveAddr(), which is a better description of
what it does.
Since we don't actually reserve an entire slot at a time anymore, the
name of this function is just confusing, and it's almost identical in
operation to virDomainPCIAddressReserveNextAddr() anyway, so remove
the *Slot() function and replace calls to it with calls to *Addr(...,
-1).
With the advent of VIR_PCI_CONNECT_AGGREGATE_SLOT, the new name is
more appropriate, since the address returned may be another address
on the same slot as last time, not necessarily a new slot.
fromConfig should be true if the caller wants
virDomainPCIAddressValidate() to loosen restrictions on its
interpretation of the pciConnectFlags. In particular, either
PCI_DEVICE or PCIE_DEVICE will be counted as equivalent to both, and
HOTPLUG will be ignored. In a few cases where libvirt was manually
overriding automatic address assignment, it was setting fromConfig to
false when validating the hardcoded manual override. This patch
changes those to fromConfig=true as a preemptive strike against any
future bugs that might otherwise surface.
Although setting virDomainPCIAddressReserveAddr()'s fromConfig=true is
correct when a PCI addres is coming from a domain's config, the *true*
purpose of the fromConfig argument is to lower restrictions on what
kind of device can plug into what kind of controller - if fromConfig
is true, then a PCIE_DEVICE can plug into a slot that is marked as
only compatible with PCI_DEVICE (and vice versa), and the HOTPLUG flag
is ignored.
For a long time there have been several calls to
virDomainPCIAddressReserveAddr() that have fromConfig incorrectly set
to false - it's correct that the addresses aren't coming from user
config, but they are coming from hardcoded exceptions in libvirt that
should, if anything, pay *even less* attention to following the
pciConnectFlags (under the assumption that the libvirt programmer knew
what they were doing).
See commit b87703cf7 for an example of an actual bug caused by the
incorrect setting of the "fromConfig" argument to
virDomainPCIAddressReserveAddr(). Although they haven't resulted in
any reported bugs, this patch corrects all the other incorrect
settings of fromConfig in calls to virDomainPCIAddressReserveAddr().
Set the VIR_PCI_CONNECT_AGGREGATE_SLOT flag for pcie-root-ports so
that they will be assigned to all the functions on a slot.
Some qemu test case outputs had to be adjusted due to the
pcie-root-ports now being put on multiple functions.
If a PCI device has VIR_PCI_CONNECT_AGGREGATE_SLOT set in its
pciConnectFlags, then during address assignment we allow multiple
instances of this type of device to be auto-assigned to multiple
functions on the same device. A slot is used for aggregating multiple
devices only if the first device assigned to that slot had
VIR_PCI_CONNECT_AGGREGATE_SLOT set. but any device types that have
AGGREGATE_SLOT set might be mix/matched on the same slot.
(NB: libvirt should never set the AGGREGATE_SLOT flag for a device
type that might need to be hotplugged. Currently it is only planned
for pcie-root-port and possibly other PCI controller types, and none
of those are hotpluggable anyway)
There aren't yet any devices that use this flag. That will be in a
later patch.
This utility function iterates through all devices looking for any
with a PCI address that has function != 0 (which implies that multiple
functions are in use on that slot), then uses an inner iterator to
find the device that's on function 0 of that same slot and sets the
"multi" in its virDomainDeviceInfo (as long as it hasn't already been
set explicitly by someone who presumably has better information than
we do).
It isn't yet called from anywhere, so will have no functional effect.
There is a very slight time advantage to beginning the search for the
next unused PCI address at the slot *after* the previous find (which
is now used), but if we do that, we will miss allocating the other
functions of the same slot (when we implement a
VIR_PCI_CONNECT_AGGREGATE_SLOT flag to support that).
virDomainPCIAddressGetNextSlot() starts searching from the last
allocated address and goes to the end of all the buses, then goes back
to the first bus and searches from there up to the starting point (in
case any address has been freed since the last time an address was
allocated. The loops for these two are almost, but not exactly, the
same, so they have remained as separate loops with the same code
inside the loop. To lessen maintenance headaches, the identical code
has been moved out into the function
virDomainPCIAddressFindUnusedFunctionOnBus(), which is called in place
of the loop contents.
setting reserveEntireSlot really accomplishes nothing - instead of
going to the trouble of computing the value for reserveEntireSlot and
then possibly setting *all* functions of the slot as in-use, we can
just set the in-use bit only for the specific function being used by a
device. Later we will know from the context (the PCI connect flags,
and whether we are reserving a specific address or asking for "the
next available") whether or not it is okay to allocate other functions
on the same slot.
Although it's not used yet, we allow specifying "-1" for the function
number when looking for the "next available slot" - this is going to
end up meaning "return the lowest available function in the slot, but
since we currently only provide a function from an otherwise unused
slot, "-1" ends up meaning "0".
When keeping track of which functions of which slots are allocated, we
will need to have more information than just the current bitmap with a
bit for each function that is currently stored for each slot in a
virDomainPCIAddressBus. To prepare for adding more per-slot info, this
patch changes "uint8_t slots" into "virDomainPCIAddressSlot slot", which
currently has a single member named "functions" that serves the same
purpose previously served directly by "slots".
Previously libvirt would only add pci-bridge devices automatically
when an address was requested for a device that required a legacy PCI
slot and none was available. This patch expands that support to
dmi-to-pci-bridge (which is needed in order to add a pci-bridge on a
machine with a pcie-root), and pcie-root-port (which is needed to add
a hotpluggable PCIe device). It does *not* automatically add
pcie-switch-upstream-ports or pcie-switch-downstream-ports (and
currently there are no plans for that).
Given the existing code to auto-add pci-bridge devices, automatically
adding pcie-root-ports is fairly straightforward. The
dmi-to-pci-bridge support is a bit tricky though, for a few reasons:
1) Although the only reason to add a dmi-to-pci-bridge is so that
there is a reasonable place to plug in a pci-bridge controller,
most of the time it's not the presence of a pci-bridge *in the
config* that triggers the requirement to add a dmi-to-pci-bridge.
Rather, it is the presence of a legacy-PCI device in the config,
which triggers auto-add of a pci-bridge, which triggers auto-add of
a dmi-to-pci-bridge (this is handled in
virDomainPCIAddressSetGrow() - if there's a request to add a
pci-bridge we'll check if there is a suitable bus to plug it into;
if not, we first add a dmi-to-pci-bridge).
2) Once there is already a single dmi-to-pci-bridge on the system,
there won't be a need for any more, even if it's full, as long as
there is a pci-bridge with an open slot - you can also plug
pci-bridges into existing pci-bridges. So we have to make sure we
don't add a dmi-to-pci-bridge unless there aren't any
dmi-to-pci-bridges *or* any pci-bridges.
3) Although it is strongly discouraged, it is legal for a pci-bridge
to be directly plugged into pcie-root, and we don't want to
auto-add a dmi-to-pci-bridge if there is already a pci-bridge
that's been forced directly into pcie-root.
Although libvirt will now automatically create a dmi-to-pci-bridge
when it's needed, the code still remains for now that forces a
dmi-to-pci-bridge on all domains with pcie-root (in
qemuDomainDefAddDefaultDevices()). That will be removed in a future
patch.
For now, the pcie-root-ports are added one to a slot, which is a bit
wasteful and means it will fail after 31 total PCIe devices (30 if
there are also some PCI devices), but helps keep the changeset down
for this patch. A future patch will have 8 pcie-root-ports sharing the
functions on a single slot.
This patch cleans up the connect flags for certain types/models of
devices that aren't PCI to return 0. In the future that may be used as
an indicator to the caller about whether or not a device needs a PCI
address. For now it's just ignored, except for in
virDomainPCIAddressEnsureAddr() - called during device hotplug - (and
in some cases actually needs to be re-set to PCI|HOTPLUGGABLE just in
case someone (in some old config) has manually set a PCI address for a
device that isn't PCI.
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 925fa4b.
Commit 19a148b 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.
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).
The code is entirely correct, but it still managed to trip me
up when I first ran into it because I did not realize right away
that VIR_PCI_CONNECT_TYPES_ENDPOINT was not a single flag, but
rather a mask including both VIR_PCI_CONNECT_TYPE_PCI_DEVICE and
VIR_PCI_CONNECT_TYPE_PCIE_DEVICE.
In order to save the next distracted traveler in PCI Address Land
some time, document this fact with a comment. Add a test case for
the behavior as well.
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.)
When I added support for the pcie-expander-bus controller in commit
bc07251f, I incorrectly thought that it only had a single slot
available. Actually it has 32 slots, just like the root complex aka
pcie-root (the part that I *did* get correct is that unlike pcie-root
a pcie-expander-bus doesn't allow any integrated endpoint devices -
only pcie-root-ports and dmi-to-pci-controllers are allowed).
In a full domain config, libvirt allows overriding the normal PCI
vs. PCI Express rules when a device address is explicitly provided
(so, e.g., you can force a legacy PCI device to plug into a PCIe port,
although libvirt would never do that on its own). However, due to a
bug libvirt doesn't give this same leeway when hotplugging devices. On
top of that, current libvirt assumes that *all* devices are legacy
PCI. The result of all this is that it's impossible to hotplug a
device into a PCIe port, even if you manually add the PCI address.
This can all be traced to the function
virDomainPCIAddressEnsureAddr(), and the fact that it calls
virDomainPCIaddressReserveSlot() for manually set addresses, and that
function hardcodes the argument "fromConfig" to false (meaning "this
address was auto-assigned, so it should be subject to stricter
validation").
Since virDomainPCIAddressReserveSlot() is just a one line simple
wrapper around virDomainPCIAddressReserveAddr() (adding in a hardcoded
reserveEntireSlot = true and fromConfig = false), all that's needed to
solve the problem with no unwanted side effects is to replace that
call for virDomainPCIAddressReserveSlot() with a direct call to
virDomainPCIAddressReserveAddr(), but with reserveEntireSlot = true,
fromConfig = true. That's what this patch does.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1337490
The 'multi' element in PCI address struct used as 'virTristateSwitch',
and its default value is 'VIR_TRISTATE_SWITCH_ABSENT'. Current PCI
process use 'false' to initialization 'multi', which is ambiguously
for assignment or comparison. This patch use '{0}' to initialize
the whole PCI address struct, which fix the 'multi' initialization
and makes code more simplify and explicitly.
Signed-off-by: Xian Han Yu <xhyubj@linux.vnet.ibm.com>
If any of the devices referenced a USB hub that does not exist,
defining the domain would either fail with:
error: An error occurred, but the cause is unknown
(if only the last hub in the path is missing)
or crash.
Return a proper error instead of crashing.
https://bugzilla.redhat.com/show_bug.cgi?id=1367130
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
I apparently misunderstood Marcel's description of what could and
couldn't be plugged into qemu's pxb-pcie controller (known as
pcie-expander-bus in libvirt) - I specifically allowed directly
connecting a pcie-switch-upstream-port, and it turns out that causes
the guest kernel to crash.
This patch forbids such a connection, and updates the xml docs
appropriately.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1361172
The virDomainPCIAddressFlagsCompatible() error logs report that a
device required a controller that accepted standard PCI endpoint
devices, or PCI Express endpoint devices, and if hotplug was required
by the configuration but not provided by the selected controller. But
the wording of the error messages was apparently confusing (according
to the bugzilla report referenced below). On top of that, if the
device was something other than an endpoint device (e.g. a
pcie-switch-downstream-port) the error message was a complete punt -
it would just say that the flags were incorrect.
This patch makes the messages for PCI/PCIe endpoint and hotplug
requirements more clear, and also specifically indicates what was the
device type when it is other than an endpoint device.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1363627
According to libxl implementation, it supports pvusb
controller of version 1.1 and version 2.0, and it
supports two types of backend, 'pvusb' (dom0 backend)
and 'qusb' (qemu backend). But currently pvusb backend
is not checked in yet.
To match libxl support, extend usb controller schema
to support two more models: qusb1 (qusb, version 1.1)
and 'qusb2' (qusb version 2.0).
Signed-off-by: Chunyan Liu <cyliu@suse.com>
