Re: [libvirt] [PATCH v3 15/18] qemu: auto-add pcie-root-port/dmi-to-pci-bridge controllers as needed

On Tue, 2016-09-20 at 15:14 -0400, Laine Stump wrote: > 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. Finally, although I > fail to see the utility of it, it is legal to have something like > this in the xml: > > <controller type='pci' model='pcie-root' index='0'/> > <controller type='pci' model='pci-bridge' index='2'/> > > and that will lead to an automatically added dmi-to-pci-bridge at > index=1 (to give the unaddressed pci-bridge a proper place to plug > in): > > <controller type='pci' model='dmi-to-pci-bridge' index='1'/> > > (for example, see the existing test case > "usb-controller-default-q35"). This is handled in > qemuDomainPCIAddressSetCreate() when it's adding in controllers to > fill holes in the indexes. I wonder how this "feature" came to be... It seems to be the reason for quite a bit of convoluted code down below, which we could avoid if this had never worked at all. As is so often the case, too late for that :(

> 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 the next > 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. > --- > src/conf/domain_addr.c | 88 ++++++++++-- > src/qemu/qemu_domain_address.c | 91 ++++++++++--- > .../qemuxml2argv-q35-pcie-autoadd.args | 57 ++++++++ > .../qemuxml2argv-q35-pcie-autoadd.xml | 51 +++++++ > tests/qemuxml2argvtest.c | 23 ++++ > .../qemuxml2xmlout-q35-pcie-autoadd.xml | 147 +++++++++++++++++++++ > tests/qemuxml2xmltest.c | 23 ++++ > 7 files changed, 448 insertions(+), 32 deletions(-) > create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-q35-pcie-autoadd.args > create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-q35-pcie-autoadd.xml > create mode 100644 tests/qemuxml2xmloutdata/qemuxml2xmlout-q35-pcie-autoadd.xml > > diff --git a/src/conf/domain_addr.c b/src/conf/domain_addr.c > index 12b5cb2..5f6f6f7 100644 > --- a/src/conf/domain_addr.c > +++ b/src/conf/domain_addr.c > @@ -82,6 +82,30 @@ virDomainPCIControllerModelToConnectType(virDomainControllerModelPCI model) > return 0; > } > > + > +static int s/int/virDomainControllerModelPCI/

> +virDomainPCIControllerConnectTypeToModel(virDomainPCIConnectFlags flags) > +{ > + if (flags & VIR_PCI_CONNECT_TYPE_PCIE_ROOT_PORT) > + return VIR_DOMAIN_CONTROLLER_MODEL_PCIE_ROOT_PORT; > + if (flags & VIR_PCI_CONNECT_TYPE_PCIE_SWITCH_UPSTREAM_PORT) > + return VIR_DOMAIN_CONTROLLER_MODEL_PCIE_SWITCH_UPSTREAM_PORT; > + if (flags & VIR_PCI_CONNECT_TYPE_PCIE_SWITCH_DOWNSTREAM_PORT) > + return VIR_DOMAIN_CONTROLLER_MODEL_PCIE_SWITCH_DOWNSTREAM_PORT; > + if (flags & VIR_PCI_CONNECT_TYPE_DMI_TO_PCI_BRIDGE) > + return VIR_DOMAIN_CONTROLLER_MODEL_DMI_TO_PCI_BRIDGE; > + if (flags & VIR_PCI_CONNECT_TYPE_PCI_EXPANDER_BUS) > + return VIR_DOMAIN_CONTROLLER_MODEL_PCI_EXPANDER_BUS; > + if (flags & VIR_PCI_CONNECT_TYPE_PCIE_EXPANDER_BUS) > + return VIR_DOMAIN_CONTROLLER_MODEL_PCIE_EXPANDER_BUS; > + if (flags & VIR_PCI_CONNECT_TYPE_PCI_BRIDGE) > + return VIR_DOMAIN_CONTROLLER_MODEL_PCI_BRIDGE; > + > + /* some connect types don't correspond to a controller model */ > + return -1; > +} > + > + > bool > virDomainPCIAddressFlagsCompatible(virPCIDeviceAddressPtr addr, > const char *addrStr, The comment right above the function states: /* Ensure addr fits in the address set, by expanding it if needed. * This will only grow if the flags say that we need a normal * hot-pluggable PCI slot. If we need a different type of slot, it * will fail. The bit about it only working when the connect flags indicate we need a hotpluggable legacy PCI slot is of course no longer accurate and should be updated, or possibly even removed altogether.

> @@ -349,32 +373,72 @@ virDomainPCIAddressSetGrow(virDomainPCIAddressSetPtr addrs, > { > int add; > size_t i; > + int model; s/int/virDomainControllerModelPCI/ > + bool needDMIToPCIBridge = false; > > add = addr->bus - addrs->nbuses + 1; > - i = addrs->nbuses; > if (add <= 0) > return 0; > > /* auto-grow only works when we're adding plain PCI devices */ No longer accurate.

> - if (!(flags & VIR_PCI_CONNECT_TYPE_PCI_DEVICE)) { > - virReportError(VIR_ERR_INTERNAL_ERROR, "%s", > - _("Cannot automatically add a new PCI bus for a " > - "device requiring a slot other than standard PCI.")); > + if (flags & VIR_PCI_CONNECT_TYPE_PCI_DEVICE) { > + model = VIR_DOMAIN_CONTROLLER_MODEL_PCI_BRIDGE; > + > + /* if there aren't yet any buses that will accept a > + * pci-bridge, and the caller is asking for one, we'll need to > + * add a dmi-to-pci-bridge first. > + */ > + needDMIToPCIBridge = true; > + for (i = 0; i < addrs->nbuses && needDMIToPCIBridge; i++) { > + if (addrs->buses[i].flags & > + VIR_PCI_CONNECT_TYPE_PCI_BRIDGE) Join those two lines.

> + needDMIToPCIBridge = false; > + } I feel like needDMIToPCIBridge = true; for (i = 0; i < addrs->nbuses; i++) { if (addrs->buses[i].flags & VIR_PCI_CONNECT_TYPE_PCI_BRIDGE) { needDMIToPCIBridge = false; break; } } would be slightly more readable, but either way is fine. > + if (needDMIToPCIBridge && add == 1) { > + /* we need to add at least two buses - one dmi-to-pci, > + * and the other the requested pci-bridge > + */ > + add++; > + addr->bus++; > + } > + } else if (flags & VIR_PCI_CONNECT_TYPE_PCI_BRIDGE) { > + model = VIR_DOMAIN_CONTROLLER_MODEL_DMI_TO_PCI_BRIDGE; I'm not so clear on this bit: if we're growing the address set to plug in a pci-bridge, can we just go ahead and assume a dmi-to-pci-bridge is what we need? What about eg. pseries machine types, where dmi-to-pci-bridge is not usable? > + } else if (flags & (VIR_PCI_CONNECT_TYPE_PCIE_DEVICE || > + VIR_PCI_CONNECT_TYPE_PCIE_SWITCH_UPSTREAM_PORT)) { Bitwise operations tend to trip me up, but shouldn't you be using | instead of || here?

Alternatively you could turn it into if ((flags & VIR_PCI_CONNECT_PCIE_DEVICE) || (flags & VIR_PCI_CONNECT_PCIE_SWITCH_UPSTREAM_PORT)) which is more obviously correct and also nicer to look at :)

> + model = VIR_DOMAIN_CONTROLLER_MODEL_PCIE_ROOT_PORT; > + } else { > + int existingContModel = virDomainPCIControllerConnectTypeToModel(flags); s/int/virDomainControllerModelPCI/

It would be also neat if you could make the variable name shorter. With a scope this limited, pretty much anything would do. > + if (existingContModel >= 0) { > + virReportError(VIR_ERR_INTERNAL_ERROR, > + _("a PCI slot is needed to connect a PCI controller " > + "model='%s', but none is available, and it " > + "cannot be automatically added"), > + virDomainControllerModelPCITypeToString(existingContModel)); > + } else { > + virReportError(VIR_ERR_INTERNAL_ERROR, > + _("Cannot automatically add a new PCI bus for a " > + "device with connect Flags %.2x"), flags); s/Flags/flags/ > + } > return -1; > } > > + i = addrs->nbuses; > + > if (VIR_EXPAND_N(addrs->buses, addrs->nbuses, add) < 0) > return -1; > > - for (; i < addrs->nbuses; i++) { > - /* Any time we auto-add a bus, we will want a multi-slot > - * bus. Currently the only type of bus we will auto-add is a > - * pci-bridge, which is hot-pluggable and provides standard > - * PCI slots. > + if (needDMIToPCIBridge) { > + /* first of the new buses is dmi-to-pci-bridge, the > + * rest are of the requested type > */ > - virDomainPCIAddressBusSetModel(&addrs->buses[i], > - VIR_DOMAIN_CONTROLLER_MODEL_PCI_BRIDGE); > + virDomainPCIAddressBusSetModel(&addrs->buses[i++], > + VIR_DOMAIN_CONTROLLER_MODEL_DMI_TO_PCI_BRIDGE); > } > + > + for (; i < addrs->nbuses; i++) > + virDomainPCIAddressBusSetModel(&addrs->buses[i], model); > + > return add; > } > > diff --git a/src/qemu/qemu_domain_address.c b/src/qemu/qemu_domain_address.c > index 1ff80e3..a9c4c32 100644 > --- a/src/qemu/qemu_domain_address.c > +++ b/src/qemu/qemu_domain_address.c > @@ -797,6 +797,11 @@ qemuDomainPCIAddressSetCreate(virDomainDefPtr def, > { > virDomainPCIAddressSetPtr addrs; > size_t i; > + bool hasPCIeRoot = false; > + int lowestDMIToPCIBridge = nbuses; > + int lowestUnaddressedPCIBridge = nbuses; > + int lowestAddressedPCIBridge = nbuses; s/int/unsigned int/g > + virDomainControllerModelPCI defaultModel; > > if ((addrs = virDomainPCIAddressSetAlloc(nbuses)) == NULL) > return NULL; > @@ -804,38 +809,84 @@ qemuDomainPCIAddressSetCreate(virDomainDefPtr def, > addrs->nbuses = nbuses; > addrs->dryRun = dryRun; > > - /* As a safety measure, set default model='pci-root' for first pci > - * controller and 'pci-bridge' for all subsequent. After setting > - * those defaults, then scan the config and set the actual model > - * for all addrs[idx]->bus that already have a corresponding > - * controller in the config. > - * > - */ > - if (nbuses > 0) > - virDomainPCIAddressBusSetModel(&addrs->buses[0], > - VIR_DOMAIN_CONTROLLER_MODEL_PCI_ROOT); > - for (i = 1; i < nbuses; i++) { > - virDomainPCIAddressBusSetModel(&addrs->buses[i], > - VIR_DOMAIN_CONTROLLER_MODEL_PCI_BRIDGE); > - } > - > for (i = 0; i < def->ncontrollers; i++) { > - size_t idx = def->controllers[i]->idx; > + virDomainControllerDefPtr cont = def->controllers[i]; Again, love this, but it should really be its own separate commit :) > + size_t idx = cont->idx; > > - if (def->controllers[i]->type != VIR_DOMAIN_CONTROLLER_TYPE_PCI) > + if (cont->type != VIR_DOMAIN_CONTROLLER_TYPE_PCI) > continue; > > if (idx >= addrs->nbuses) { > virReportError(VIR_ERR_INTERNAL_ERROR, > _("Inappropriate new pci controller index %zu " > - "not found in addrs"), idx); > + "exceeds addrs array length"), idx); ... And this as well, I guess? > goto error; > } > > - if (virDomainPCIAddressBusSetModel(&addrs->buses[idx], > - def->controllers[i]->model) < 0) > + if (virDomainPCIAddressBusSetModel(&addrs->buses[idx], cont->model) < 0) > goto error; > + > + /* we'll use all this info later to determine if we need > + * to add a dmi-to-pci-bridge due to unaddressed pci-bridge controllers > + */ > + if (cont->model == VIR_DOMAIN_CONTROLLER_MODEL_PCIE_ROOT) { > + hasPCIeRoot = true; > + } else if (cont->model == > + VIR_DOMAIN_CONTROLLER_MODEL_DMI_TO_PCI_BRIDGE) { These can be a single line - we apparently don't really care about enforcing the 80 column limit :) > + if (lowestDMIToPCIBridge > idx) > + lowestDMIToPCIBridge = idx; > + } else if (cont->model == VIR_DOMAIN_CONTROLLER_MODEL_PCI_BRIDGE) { > + if (virDeviceInfoPCIAddressWanted(&cont->info)) { > + if (lowestUnaddressedPCIBridge > idx) > + lowestUnaddressedPCIBridge = idx; > + } else { > + if (lowestAddressedPCIBridge > idx) > + lowestAddressedPCIBridge = idx; > + } > } > + } > + > + if (nbuses > 0 && !addrs->buses[0].model) { > + if (virDomainPCIAddressBusSetModel(&addrs->buses[0], > + VIR_DOMAIN_CONTROLLER_MODEL_PCI_ROOT) < 0) > + goto error; > + } Shouldn't we use either PCI_ROOT or PCIE_ROOT based on the machine type here? And set hasPCIeRoot *after* doing so? Sorry for the questions, I guess this is the point in the patch where I got a bit lost :( > + /* Now fill in a reasonable model for all the buses in the set > + * that don't yet have a corresponding controller in the domain > + * config. In the rare (and actually fairly idiotic, but still > + * allowed for some reason) case that a domain has 1) a pcie-root > + * at index 0, 2) *no* dmi-to-pci-bridge (or pci-bridge that was > + * manually addressed to sit directly on pcie-root), and 3) does > + * have an unaddressed pci-bridge at an index > 1, then we need to > + * add a dmi-to-pci-bridge. > + */ > + > + if (!hasPCIeRoot) > + defaultModel = VIR_DOMAIN_CONTROLLER_MODEL_PCI_BRIDGE; Add curly braces here as well as below. > + else if (lowestUnaddressedPCIBridge < MIN(lowestAddressedPCIBridge, > + lowestDMIToPCIBridge)) > + defaultModel = VIR_DOMAIN_CONTROLLER_MODEL_DMI_TO_PCI_BRIDGE; Again, a bit lost here, sorry :( Basically if we've found a PCI bridge without address that can't be plugged into any existing PCI bridge or DMI-to-PCI bridge, we want to add a DMI-to-PCI bridge so that we have somewhere to plug it in, right? > + else > + defaultModel = VIR_DOMAIN_CONTROLLER_MODEL_PCIE_ROOT_PORT; > + > + for (i = 1; i < addrs->nbuses; i++) { > + > + if (addrs->buses[i].model) > + continue; > + > + if (virDomainPCIAddressBusSetModel(&addrs->buses[i], defaultModel) < 0) > + goto error; > + > + VIR_DEBUG("Auto-adding <controller type='pci' model='%s' index='%zu'/>", > + virDomainControllerModelPCITypeToString(defaultModel), i); > + /* only add a single dmi-to-pci-bridge, then add pcie-root-port > + * for any other unspecified controller indexes. > + */ > + if (hasPCIeRoot) > + defaultModel = VIR_DOMAIN_CONTROLLER_MODEL_PCIE_ROOT_PORT; Okay, so * if the machine has a PCIe Root Bus and we have a PCI bridge that we don't know where to plug (no existing legacy PCI hierarchy below it), we add a single DMI-to-PCI bridge and then plug PCIe Root Ports into PCIe Root Ports until we have as many buses as we need

* if the machine has a PCIe Root Bus and we're not in the situation above when it comes to PCI bridges (there is an existing legacy PCI hierarchy below it), we plug PCIe Root Ports into PCIe Root Ports until we have as many buses as we need * otherwise (no PCIe Root Bus) we just plug PCI bridges into PCI bridges until we have as many buses as we need Does that sound about right?

> diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c > index a7e21fd..cfa522c 100644 > --- a/tests/qemuxml2argvtest.c > +++ b/tests/qemuxml2argvtest.c > @@ -1739,6 +1739,29 @@ mymain(void) > QEMU_CAPS_PCI_MULTIFUNCTION, QEMU_CAPS_ICH9_USB_EHCI1, > QEMU_CAPS_NEC_USB_XHCI, > QEMU_CAPS_DEVICE_VIDEO_PRIMARY); > + /* same as q35-pcie, but all PCI controllers are added automatically */ > + DO_TEST("q35-pcie-autoadd", > + QEMU_CAPS_VIRTIO_PCI_DISABLE_LEGACY, > + QEMU_CAPS_DEVICE_VIRTIO_RNG, > + QEMU_CAPS_OBJECT_RNG_RANDOM, > + QEMU_CAPS_NETDEV, > + QEMU_CAPS_DEVICE_VIRTIO_NET, > + QEMU_CAPS_DEVICE_VIRTIO_GPU, > + QEMU_CAPS_DEVICE_VIRTIO_GPU_VIRGL, > + QEMU_CAPS_VIRTIO_KEYBOARD, > + QEMU_CAPS_VIRTIO_MOUSE, > + QEMU_CAPS_VIRTIO_TABLET, > + QEMU_CAPS_VIRTIO_INPUT_HOST, > + QEMU_CAPS_VIRTIO_SCSI, > + QEMU_CAPS_FSDEV, > + QEMU_CAPS_FSDEV_WRITEOUT, > + QEMU_CAPS_DEVICE_PCI_BRIDGE, > + QEMU_CAPS_DEVICE_DMI_TO_PCI_BRIDGE, > + QEMU_CAPS_DEVICE_IOH3420, > + QEMU_CAPS_ICH9_AHCI, > + QEMU_CAPS_PCI_MULTIFUNCTION, QEMU_CAPS_ICH9_USB_EHCI1, You've used one line per capability everywhere except for this line. Same for test cases added earlier in the series, now that I look at it. Weird :)

> + QEMU_CAPS_NEC_USB_XHCI, > + QEMU_CAPS_DEVICE_VIDEO_PRIMARY); > DO_TEST("pcie-root-port", > QEMU_CAPS_DEVICE_PCI_BRIDGE, > QEMU_CAPS_DEVICE_DMI_TO_PCI_BRIDGE, > diff --git a/tests/qemuxml2xmloutdata/qemuxml2xmlout-q35-pcie-autoadd.xml b/tests/qemuxml2xmloutdata/qemuxml2xmlout-q35-pcie-autoadd.xml > new file mode 100644 > index 0000000..b27dbe7 > --- /dev/null > +++ b/tests/qemuxml2xmloutdata/qemuxml2xmlout-q35-pcie-autoadd.xml > @@ -0,0 +1,147 @@ > +<domain type='qemu'> > + <name>q35-test</name> > + <uuid>11dbdcdd-4c3b-482b-8903-9bdb8c0a2774</uuid> > + <memory unit='KiB'>2097152</memory> > + <currentMemory unit='KiB'>2097152</currentMemory> > + <vcpu placement='static' cpuset='0-1'>2</vcpu> > + <os> > + <type arch='x86_64' machine='q35'>hvm</type> > + <boot dev='hd'/> > + </os> > + <clock offset='utc'/> > + <on_poweroff>destroy</on_poweroff> > + <on_reboot>restart</on_reboot> > + <on_crash>destroy</on_crash> > + <devices> > + <emulator>/usr/libexec/qemu-kvm</emulator> > + <disk type='block' device='disk'> > + <source dev='/dev/HostVG/QEMUGuest1'/> > + <target dev='vdb' bus='virtio'/> > + <address type='pci' domain='0x0000' bus='0x08' slot='0x00' function='0x0'/> > + </disk> > + <controller type='virtio-serial' index='0'> > + <address type='pci' domain='0x0000' bus='0x05' slot='0x00' function='0x0'/> > + </controller> > + <controller type='scsi' index='0' model='virtio-scsi'> > + <address type='pci' domain='0x0000' bus='0x06' slot='0x00' function='0x0'/> > + </controller> > + <controller type='usb' index='0' model='nec-xhci'> > + <address type='pci' domain='0x0000' bus='0x07' slot='0x00' function='0x0'/> > + </controller> > + <controller type='sata' index='0'> > + <address type='pci' domain='0x0000' bus='0x00' slot='0x1f' function='0x2'/> > + </controller> > + <controller type='pci' index='0' model='pcie-root'/> > + <controller type='pci' index='1' model='dmi-to-pci-bridge'> > + <model name='i82801b11-bridge'/> > + <address type='pci' domain='0x0000' bus='0x00' slot='0x1e' function='0x0'/> > + </controller> A DMI-to-PCI bridge with index='1' has been added automatically here... > + <controller type='pci' index='2' model='pcie-root-port'> > + <model name='ioh3420'/> > + <target chassis='2' port='0x10'/> > + <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/> > + </controller> > + <controller type='pci' index='3' model='pcie-root-port'> > + <model name='ioh3420'/> > + <target chassis='3' port='0x18'/> > + <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/> > + </controller> > + <controller type='pci' index='4' model='pcie-root-port'> > + <model name='ioh3420'/> > + <target chassis='4' port='0x20'/> > + <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/> > + </controller> > + <controller type='pci' index='5' model='pcie-root-port'> > + <model name='ioh3420'/> > + <target chassis='5' port='0x28'/> > + <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/> > + </controller> > + <controller type='pci' index='6' model='pcie-root-port'> > + <model name='ioh3420'/> > + <target chassis='6' port='0x30'/> > + <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/> > + </controller> > + <controller type='pci' index='7' model='pcie-root-port'> > + <model name='ioh3420'/> > + <target chassis='7' port='0x38'/> > + <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/> > + </controller> > + <controller type='pci' index='8' model='pcie-root-port'> > + <model name='ioh3420'/> > + <target chassis='8' port='0x40'/> > + <address type='pci' domain='0x0000' bus='0x00' slot='0x08' function='0x0'/> > + </controller> > + <controller type='pci' index='9' model='pcie-root-port'> > + <model name='ioh3420'/> > + <target chassis='9' port='0x48'/> > + <address type='pci' domain='0x0000' bus='0x00' slot='0x09' function='0x0'/> > + </controller> > + <controller type='pci' index='10' model='pcie-root-port'> > + <model name='ioh3420'/> > + <target chassis='10' port='0x50'/> > + <address type='pci' domain='0x0000' bus='0x00' slot='0x0a' function='0x0'/> > + </controller> > + <controller type='pci' index='11' model='pcie-root-port'> > + <model name='ioh3420'/> > + <target chassis='11' port='0x58'/> > + <address type='pci' domain='0x0000' bus='0x00' slot='0x0b' function='0x0'/> > + </controller> > + <controller type='pci' index='12' model='pcie-root-port'> > + <model name='ioh3420'/> > + <target chassis='12' port='0x60'/> > + <address type='pci' domain='0x0000' bus='0x00' slot='0x0c' function='0x0'/> > + </controller> > + <controller type='pci' index='13' model='pcie-root-port'> > + <model name='ioh3420'/> > + <target chassis='13' port='0x68'/> > + <address type='pci' domain='0x0000' bus='0x00' slot='0x0d' function='0x0'/> > + </controller> > + <controller type='pci' index='14' model='pcie-root-port'> > + <model name='ioh3420'/> > + <target chassis='14' port='0x70'/> > + <address type='pci' domain='0x0000' bus='0x00' slot='0x0e' function='0x0'/> > + </controller> > + <filesystem type='mount' accessmode='passthrough'> > + <source dir='/export/to/guest'/> > + <target dir='/import/from/host'/> > + <address type='pci' domain='0x0000' bus='0x02' slot='0x00' function='0x0'/> > + </filesystem> > + <interface type='user'> > + <mac address='00:11:22:33:44:55'/> > + <model type='virtio'/> > + <address type='pci' domain='0x0000' bus='0x03' slot='0x00' function='0x0'/> > + </interface> > + <interface type='user'> > + <mac address='00:11:22:33:44:66'/> > + <model type='e1000e'/> > + <address type='pci' domain='0x0000' bus='0x04' slot='0x00' function='0x0'/> > + </interface> > + <input type='passthrough' bus='virtio'> > + <source evdev='/dev/input/event1234'/> > + <address type='pci' domain='0x0000' bus='0x0b' slot='0x00' function='0x0'/> > + </input> > + <input type='mouse' bus='virtio'> > + <address type='pci' domain='0x0000' bus='0x0c' slot='0x00' function='0x0'/> > + </input> > + <input type='keyboard' bus='virtio'> > + <address type='pci' domain='0x0000' bus='0x0d' slot='0x00' function='0x0'/> > + </input> > + <input type='tablet' bus='virtio'> > + <address type='pci' domain='0x0000' bus='0x0e' slot='0x00' function='0x0'/> > + </input> > + <input type='mouse' bus='ps2'/> > + <input type='keyboard' bus='ps2'/> > + <video> > + <model type='virtio' heads='1' primary='yes'/> > + <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x0'/> > + </video> > + <memballoon model='virtio'> > + <address type='pci' domain='0x0000' bus='0x09' slot='0x00' function='0x0'/> > + </memballoon> > + <rng model='virtio'> > + <rate bytes='123' period='1234'/> > + <backend model='random'>/dev/urandom</backend> > + <address type='pci' domain='0x0000' bus='0x0a' slot='0x00' function='0x0'/> > + </rng> ... but it's not being used by any of the devices. So why would it be added in the first place?

-- Andrea Bolognani / Red Hat / Virtualization