From 725fe06bebb3f2be2ff685064eccab320ff8aa4c Mon Sep 17 00:00:00 2001

Message-Id: <725fe06bebb3f2be2ff685064eccab320ff8aa4c.1380703761.git.jdenemar@redhat.com>

From: Laine Stump <laine@laine.org>

Date: Fri, 27 Sep 2013 05:19:41 -0600

Subject: [PATCH] qemu: allow some PCI devices to be attached to PCIe slots

Part of the resolution to:

   https://bugzilla.redhat.com/show_bug.cgi?id=1003983

Although most devices available in qemu area defined as PCI devices,

and strictly speaking should only be attached via a PCI slot, in

practice qemu allows them to be attached to a PCIe slot and sometimes

this makes sense.

For example, The UHCI and EHCI USB controllers are usually attached

directly to the PCIe "root complex" (i.e. PCIe slots) on real

hardware, so that should be possible for a Q35-based qemu virtual

machine as well.

We still want to prefer a standard PCI slot when auto-assigning

addresses, though, and in general to disallow attaching PCI devices

via PCIe slots.

This patch makes that possible by adding a new

QEMU_PCI_CONNECT_TYPE_EITHER_IF_CONFIG flag. Three things are done

with this flag:

1) It is set for the "pcie-root" controller

2) qemuCollectPCIAddress() now has a set of nested switches that set

this "EITHER" flag for devices that we want to allow connecting to

pcie-root when specifically requested in the config.

3) qemuDomainPCIAddressFlagsCompatible() adds this new flag to the

"flagsMatchMask" if the address being checked came from config rather

than being newly auto-allocated by libvirt (this knowledge is

conveniently already available in the "fromConfig" arg).

Now any device having the EITHER flag set can be connected to

pcie-root if explicitly requested, but auto-allocated addresses for

those devices will still be standard PCI slots instead.

This patch only loosens the restrictions on devices that have been

specifically requested, but the setup is such that it should be fairly

easy to add new devices.

(cherry picked from commit 07af519298996f4341f62542c31c1c01969eeceb)

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>

---

 src/qemu/qemu_command.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++---

 src/qemu/qemu_command.h |  4 ++++

 2 files changed, 51 insertions(+), 3 deletions(-)

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c

index 85eedd5..f025e8c 100644

--- a/src/qemu/qemu_command.c

+++ b/src/qemu/qemu_command.c

@@ -1454,12 +1454,16 @@ qemuDomainPCIAddressFlagsCompatible(virDevicePCIAddressPtr addr,

 {

     virErrorNumber errType = (fromConfig

                               ? VIR_ERR_XML_ERROR : VIR_ERR_INTERNAL_ERROR);

+    qemuDomainPCIConnectFlags flagsMatchMask = QEMU_PCI_CONNECT_TYPES_MASK;

+

+    if (fromConfig)

+       flagsMatchMask |= QEMU_PCI_CONNECT_TYPE_EITHER_IF_CONFIG;

     /* If this bus doesn't allow the type of connection (PCI

      * vs. PCIe) required by the device, or if the device requires

      * hot-plug and this bus doesn't have it, return false.

      */

-    if (!(devFlags & busFlags & QEMU_PCI_CONNECT_TYPES_MASK)) {

+    if (!(devFlags & busFlags & flagsMatchMask)) {

         if (reportError) {

             if (devFlags & QEMU_PCI_CONNECT_TYPE_PCI) {

                 virReportError(errType,

@@ -1578,8 +1582,12 @@ qemuDomainPCIAddressBusSetModel(qemuDomainPCIAddressBusPtr bus,

         bus->maxSlot = QEMU_PCI_ADDRESS_SLOT_LAST;

         break;

     case VIR_DOMAIN_CONTROLLER_MODEL_PCIE_ROOT:

-        /* slots 1 - 31, PCIe devices only, no hotplug */

-        bus->flags = QEMU_PCI_CONNECT_TYPE_PCIE;

+        /* slots 1 - 31, no hotplug, PCIe only unless the address was

+         * specified in user config *and* the particular device being

+         * attached also allows it

+         */

+        bus->flags = (QEMU_PCI_CONNECT_TYPE_PCIE |

+                      QEMU_PCI_CONNECT_TYPE_EITHER_IF_CONFIG);

         bus->minSlot = 1;

         bus->maxSlot = QEMU_PCI_ADDRESS_SLOT_LAST;

         break;

@@ -1717,6 +1725,42 @@ qemuCollectPCIAddress(virDomainDefPtr def ATTRIBUTE_UNUSED,

              */

             flags = QEMU_PCI_CONNECT_TYPE_PCI | QEMU_PCI_CONNECT_TYPE_PCIE;

             break;

+

+        case VIR_DOMAIN_CONTROLLER_TYPE_USB:

+           /* allow UHCI and EHCI controllers to be manually placed on

+            * the PCIe bus (but don't put them there automatically)

+            */

+           switch (device->data.controller->model) {

+           case VIR_DOMAIN_CONTROLLER_MODEL_USB_EHCI:

+           case VIR_DOMAIN_CONTROLLER_MODEL_USB_ICH9_EHCI1:

+           case VIR_DOMAIN_CONTROLLER_MODEL_USB_ICH9_UHCI1:

+           case VIR_DOMAIN_CONTROLLER_MODEL_USB_ICH9_UHCI2:

+           case VIR_DOMAIN_CONTROLLER_MODEL_USB_ICH9_UHCI3:

+           case VIR_DOMAIN_CONTROLLER_MODEL_USB_VT82C686B_UHCI:

+              flags = (QEMU_PCI_CONNECT_TYPE_PCI |

+                       QEMU_PCI_CONNECT_TYPE_EITHER_IF_CONFIG);

+              break;

+           case VIR_DOMAIN_CONTROLLER_MODEL_USB_NEC_XHCI:

+              /* should this be PCIE-only? Or do we need to allow PCI

+               * for backward compatibility?

+               */

+              flags = QEMU_PCI_CONNECT_TYPE_PCI | QEMU_PCI_CONNECT_TYPE_PCIE;

+              break;

+           case VIR_DOMAIN_CONTROLLER_MODEL_USB_PCI_OHCI:

+           case VIR_DOMAIN_CONTROLLER_MODEL_USB_PIIX3_UHCI:

+           case VIR_DOMAIN_CONTROLLER_MODEL_USB_PIIX4_UHCI:

+              /* Allow these for PCI only */

+              break;

+           }

+        }

+        break;

+

+    case VIR_DOMAIN_DEVICE_SOUND:

+        switch (device->data.sound->model) {

+        case VIR_DOMAIN_SOUND_MODEL_ICH6:

+            flags = (QEMU_PCI_CONNECT_TYPE_PCI |

+                     QEMU_PCI_CONNECT_TYPE_EITHER_IF_CONFIG);

+            break;

         }

         break;

diff --git a/src/qemu/qemu_command.h b/src/qemu/qemu_command.h

index a9854a3..47022e6 100644

--- a/src/qemu/qemu_command.h

+++ b/src/qemu/qemu_command.h

@@ -246,6 +246,10 @@ typedef enum {

    /* PCI devices can connect to this bus */

    QEMU_PCI_CONNECT_TYPE_PCIE    = 1 << 3,

    /* PCI Express devices can connect to this bus */

+   QEMU_PCI_CONNECT_TYPE_EITHER_IF_CONFIG = 1 << 4,

+   /* PCI *and* PCIe devices allowed, if the address

+    * was specified in the config by the user

+    */

 } qemuDomainPCIConnectFlags;

 /* a combination of all bit that describe the type of connections

-- 

1.8.3.2