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 ee0d97a and parts of commits 16db8d2
and d6d54cd1.
This controller can be connected only to a port on a
pcie-switch-upstream-port. It provides a single hotpluggable port that
will accept any PCI or PCIe device, as well as any device requiring a
pcie-*-port (the only current example of such a device is the
pcie-switch-upstream-port).
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.
The function that auto-assigns PCI addresses was written with the
hardcoded assumptions that any PCI bus would have slots available
starting at 1 and ending at 31. This isn't true for many types of
controllers (some have a single slot/port at 0, some have slots/ports
from 0 to 31). This patch updates that function to remove the
hardcoded assumptions. It will properly find/assign addresses for
devices that can only connect to pcie-(root|downstream)-port (which
have minSlot/maxSlot of 0/0) or a pcie-switch-upstream-port (0/31).
It still will not auto-create a new bus of the proper kind for these
connections when one doesn't exist, that task is for another day.
Certain PCI buses don't support hotplug, and when automatically
assigning PCI addresses for devices, libvirt is very conservative in
its assumptions about whether or not a device will need to be
hotplugged/unplugged in the future. But if the user manually assigns
an address, they likely are aware of any hotplug requirements of the
device (or at least they should be).
In short, after this patch, automatically PCI address assignment will
assume that the device must be plugged in to a hot-pluggable slot, but
manually assignment can place the device in any bus that is
compatible, regardless of whether or not it supports hotplug. If the
user makes a mistake and plugs the device into a bus that doesn't
support hotplug, then later tries to do a hot-unplug, qemu will give
an appropriate error.
(in the future we may want to add a "hotpluggable" attribute to all
devices, with default being "yes" for autoassign, and "no" for manual
assign).
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).
==19015== 8 bytes in 1 blocks are definitely lost in loss record 34 of 1,049
==19015== at 0x4C29F80: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==19015== by 0x4C2C32F: realloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==19015== by 0x52AD888: virReallocN (viralloc.c:245)
==19015== by 0x52AD97E: virExpandN (viralloc.c:294)
==19015== by 0x52ADC51: virInsertElementsN (viralloc.c:436)
==19015== by 0x5335864: virDomainVirtioSerialAddrSetAddController (domain_addr.c:816)
==19015== by 0x53358E0: virDomainVirtioSerialAddrSetAddControllers (domain_addr.c:839)
==19015== by 0x1DD5513B: qemuDomainAssignVirtioSerialAddresses (qemu_command.c:1422)
==19015== by 0x1DD55A6E: qemuDomainAssignAddresses (qemu_command.c:1711)
==19015== by 0x1DDA5818: qemuProcessStart (qemu_process.c:4616)
==19015== by 0x1DDF1807: qemuDomainObjStart (qemu_driver.c:7265)
==19015== by 0x1DDF1A66: qemuDomainCreateWithFlags (qemu_driver.c:7320)
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
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.
It returns NULL on failure. Checking if the negation of it
is less than zero makes no sense. (Found by coverity after moving
the code)
In another case, the return value wasn't checked at all.
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.
