From 093fe7d6bde7f224200e7f2877949f3196002bd7 Mon Sep 17 00:00:00 2001

Message-Id: <093fe7d6bde7f224200e7f2877949f3196002bd7@dist-git>

From: Laine Stump <laine@laine.org>

Date: Wed, 10 Aug 2016 11:00:12 -0400

Subject: [PATCH] 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

(cherry picked from commit b70e54342bbd1756234e07ed6b22bdd3cd12b689)

---

 docs/formatdomain.html.in | 20 +++++++++++---------

 src/conf/domain_addr.c    |  7 ++-----

 2 files changed, 13 insertions(+), 14 deletions(-)

diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in

index c2e261d..b74057f 100644

--- a/docs/formatdomain.html.in

+++ b/docs/formatdomain.html.in

@@ -3333,15 +3333,17 @@

           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-port 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).

       
node

diff --git a/src/conf/domain_addr.c b/src/conf/domain_addr.c

index 61c4074..c22329d 100644

--- a/src/conf/domain_addr.c

+++ b/src/conf/domain_addr.c

@@ -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;

-- 

2.9.2