Re: [libvirt] [PATCH 2/3] conf: don't allow connecting upstream-port directly to pce-expander-bus

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 ---   docs/formatdomain.html.in | 24 +++++++++++++-----------   src/conf/domain_addr.c    |  9 +++------   2 files changed, 16 insertions(+), 17 deletions(-)   diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in index 5acb3b9..eddb8dd 100644 --- a/docs/formatdomain.html.in +++ b/docs/formatdomain.html.in @@ -3346,8 +3346,8 @@           this expander bus, and bus numbers less than the specified           value will be available to the next lower expander-bus (or the           root-bus if there are no lower expander buses). If you do not -        specify a busNumber, libvirt will find the lowest existing -        busNumber in all other expander buses (or use 256 if there are +        specify a busNr, libvirt will find the lowest existing +        busNr in all other expander buses (or use 256 if there are           no others) and auto-assign the busNr of that found bus - 2,           which provides one bus number for the pci-expander-bus and one           for the pci-bridge that is automatically attached to it (if

@@ -3360,15 +3360,17 @@             2nd bus-number is just being reserved for the pcie-root-port             that must necessarily be connected to the bus in order to             actually plug in an endpoint device. If you intend to plug -          multiple devices into a pcie-expander-bus, you must instead -          connect a pcie-switch-upstream-port to the -          pcie-expander-bus, and multiple pcie-switch-downstream-ports -          to the pcie-switch-downstream-port, and of course for this -          to work properly, you will need to decrease the -          pcie-expander-bus' busNr accordingly so that there are -          enough unused bus numbers above it to accomodate giving out -          one bus number for the upstream-port and one for each -          downstream-port). +          multiple devices into a pcie-expander-bus, you must connect +          a pcie-switch-upstream-port to the pcie-root-bus that is

+          plugged into the pcie-expander-bus, and multiple +          pcie-switch-downstream-ports to the +          pcie-switch-upstream-port, and of course for this to work +          properly, you will need to decrease the pcie-expander-bus' +          busNr accordingly so that there are enough unused bus +          numbers above it to accomodate giving out one bus number for +          the upstream-port and one for each downstream-port (in +          addition to the pcie-root-port and the pcie-expander-bus +          itself).           </p>         </dd>         <dt><code>node</code></dt> diff --git a/src/conf/domain_addr.c b/src/conf/domain_addr.c index 98176e2..faf5a5a 100644 --- a/src/conf/domain_addr.c +++ b/src/conf/domain_addr.c @@ -161,7 +161,7 @@ virDomainPCIAddressFlagsCompatible(virPCIDeviceAddressPtr addr,           }           return false;       } -    return true; +   return true;   }    

@@ -291,11 +291,8 @@ virDomainPCIAddressBusSetModel(virDomainPCIAddressBusPtr bus,           bus->maxSlot = VIR_PCI_ADDRESS_SLOT_LAST;           break;       case VIR_DOMAIN_CONTROLLER_MODEL_PCIE_EXPANDER_BUS: -        /* single slot, no hotplug, only accepts pcie-root-port or -         * pcie-switch-upstream-port. -         */ -        bus->flags = (VIR_PCI_CONNECT_TYPE_PCIE_ROOT_PORT -                      | VIR_PCI_CONNECT_TYPE_PCIE_SWITCH_UPSTREAM_PORT); +        /* single slot, no hotplug, only accepts pcie-root-port */ +        bus->flags = VIR_PCI_CONNECT_TYPE_PCIE_ROOT_PORT;           bus->minSlot = 0;           bus->maxSlot = 0;           break;