nodedev: Expose PCI header type

If we expose this information, which is one byte in every PCI config file, we let all mgmt apps know whether the device itself is an endpoint or not so it's easier for them to decide whether such device can be passed through into a VM (endpoint) or not (*-bridge). Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1317531 Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
2024-12-22 05:35:25 +00:00 · 2016-03-15 12:22:03 +01:00 · 2016-03-15 12:22:03 +01:00 · d77ffb6876
commit d77ffb6876
parent 0d8f45246a
11 changed files with 152 additions and 21 deletions
--- a/docs/formatnode.html.in
+++ b/docs/formatnode.html.in
@ -97,27 +97,38 @@
              <dd>
                This optional element can occur multiple times. If it
                exists, it has a mandatory <code>type</code> attribute
-                which will be set to
-                either <code>physical_function</code>
-                or <code>virtual_functions</code>. If the type
-                is <code>physical_function</code>, there will be a
-                single <code>address</code> subelement which contains
-                the PCI address of the SRIOV Physical Function (PF)
-                that is the parent of this device (and this device is,
-                by implication, an SRIOV Virtual Function (VF)). If
-                the type is <code>virtual_functions</code>, then this
-                device is an SRIOV PF, and the capability element will
-                have a list of <code>address</code> subelements, one
-                for each VF on this PF. If the host system supports
-                reporting it (via the "sriov_maxvfs" file in the
-                device's sysfs directory) the capability element will
-                also have an attribute named <code>maxCount</code>
-                which is the maximum number of SRIOV VFs supported by
-                this device, which could be higher than the number of
-                VFs that are curently active <span class="since">since
-                1.3.0</span>; in this case, even if there are
-                currently no active VFs the virtual_functions
-                capabililty will still be shown.
+                which will be set to:
+                <dl>
+                  <dt><code>physical_function</code></dt>
+                  <dd>
+                    That means there will be a single <code>address</code>
+                    subelement which contains the PCI address of the SRIOV
+                    Physical Function (PF) that is the parent of this device
+                    (and this device is, by implication, an SRIOV Virtual
+                    Function (VF)).
+                  </dd>
+                  <dt><code>virtual_function</code></dt>
+                  <dd>
+                    In this case this device is an SRIOV PF, and the capability
+                    element will have a list of <code>address</code>
+                    subelements, one for each VF on this PF. If the host system
+                    supports reporting it (via the "sriov_maxvfs" file in the
+                    device's sysfs directory) the capability element will also
+                    have an attribute named <code>maxCount</code> which is the
+                    maximum number of SRIOV VFs supported by this device, which
+                    could be higher than the number of VFs that are curently
+                    active <span class="since">since 1.3.0</span>; in this case,
+                    even if there are currently no active VFs the
+                    virtual_functions capabililty will still be shown.
+                  </dd>
+                  <dt><code>pci-bridge</code> or <code>cardbus-bridge</code></dt>
+                  <dd>
+                    This shows merely that the lower 7 bits of PCI header type
+                    have either value of 1 or 2 respectively.  Usually this
+                    means such device cannot be used for PCI passthrough.
+                    <span class="since">Since 1.3.3</span>
+                  </dd>
+                </dl>
              </dd>
              <dt><code>numa</code></dt>
              <dd>
--- a/docs/schemas/nodedev.rng
+++ b/docs/schemas/nodedev.rng
@ -168,6 +168,17 @@
      </element>
    </optional>

+    <optional>
+      <element name='capability'>
+        <attribute name='type'>
+          <choice>
+            <value>pci-bridge</value>
+            <value>cardbus-bridge</value>
+          </choice>
+        </attribute>
+      </element>
+    </optional>
+
    <optional>
      <element name='pci-express'>
        <zeroOrMore>
--- a/src/conf/node_device_conf.c
+++ b/src/conf/node_device_conf.c
@ -402,6 +402,12 @@ char *virNodeDeviceDefFormat(const virNodeDeviceDef *def)
            if (data->pci_dev.numa_node >= 0)
                virBufferAsprintf(&buf, "<numa node='%d'/>\n",
                                  data->pci_dev.numa_node);
+
+            if (data->pci_dev.hdrType) {
+                virBufferAsprintf(&buf, "<capability type='%s'/>\n",
+                                  virPCIHeaderTypeToString(data->pci_dev.hdrType));
+            }
+
            if (data->pci_dev.flags & VIR_NODE_DEV_CAP_FLAG_PCIE)
                virPCIEDeviceInfoFormat(&buf, data->pci_dev.pci_express);
            break;
@ -1272,6 +1278,7 @@ virNodeDevCapPCIDevParseXML(xmlXPathContextPtr ctxt,
    xmlNodePtr orignode, iommuGroupNode, pciExpress;
    int ret = -1;
    virPCIEDeviceInfoPtr pci_express = NULL;
+    char *tmp = NULL;

    orignode = ctxt->node;
    ctxt->node = node;
@ -1329,6 +1336,18 @@ virNodeDevCapPCIDevParseXML(xmlXPathContextPtr ctxt,
                                          _("invalid NUMA node ID supplied for '%s'")) < 0)
        goto out;

+    if ((tmp = virXPathString("string(./capability[1]/@type)", ctxt))) {
+        int hdrType = virPCIHeaderTypeFromString(tmp);
+
+        if (hdrType <= 0) {
+            virReportError(VIR_ERR_INTERNAL_ERROR,
+                           _("Unknown PCI header type '%s'"), tmp);
+            goto out;
+        }
+
+        data->pci_dev.hdrType = hdrType;
+    }
+
    if ((pciExpress = virXPathNode("./pci-express[1]", ctxt))) {
        if (VIR_ALLOC(pci_express) < 0)
            goto out;
@ -1343,6 +1362,7 @@ virNodeDevCapPCIDevParseXML(xmlXPathContextPtr ctxt,

    ret = 0;
 out:
+    VIR_FREE(tmp);
    virPCIEDeviceInfoFree(pci_express);
    ctxt->node = orignode;
    return ret;
--- a/src/conf/node_device_conf.h
+++ b/src/conf/node_device_conf.h
@ -119,6 +119,7 @@ typedef struct _virNodeDevCapData {
            unsigned int iommuGroupNumber;
            int numa_node;
            virPCIEDeviceInfoPtr pci_express;
+            int hdrType; /* enum virPCIHeaderType or -1 */
        } pci_dev;
        struct {
            unsigned int bus;
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@ -2010,11 +2010,14 @@ virPCIDeviceSetUsedBy;
 virPCIDeviceUnbind;
 virPCIDeviceWaitForCleanup;
 virPCIEDeviceInfoFree;
+virPCIGetHeaderType;
 virPCIGetNetName;
 virPCIGetPhysicalFunction;
 virPCIGetVirtualFunctionIndex;
 virPCIGetVirtualFunctionInfo;
 virPCIGetVirtualFunctions;
+virPCIHeaderTypeFromString;
+virPCIHeaderTypeToString;
 virPCIIsVirtualFunction;
 virPCIStubDriverTypeFromString;
 virPCIStubDriverTypeToString;
--- a/src/node_device/node_device_udev.c
+++ b/src/node_device/node_device_udev.c
@ -506,6 +506,9 @@ static int udevProcessPCI(struct udev_device *device,

    /* We need to be root to read PCI device configs */
    if (priv->privileged) {
+        if (virPCIGetHeaderType(pciDev, &data->pci_dev.hdrType) < 0)
+            goto out;
+
        if (virPCIDeviceIsPCIExpress(pciDev) > 0) {
            if (VIR_ALLOC(pci_express) < 0)
                goto out;
--- a/src/util/virpci.c
+++ b/src/util/virpci.c
@ -62,6 +62,12 @@ VIR_ENUM_IMPL(virPCIStubDriver, VIR_PCI_STUB_DRIVER_LAST,
              "vfio-pci", /* VFIO */
 );

+VIR_ENUM_IMPL(virPCIHeader, VIR_PCI_HEADER_LAST,
+              "endpoint",
+              "pci-bridge",
+              "cardbus-bridge",
+);
+
 struct _virPCIDevice {
    virPCIDeviceAddress address;

@ -2883,6 +2889,33 @@ virPCIDeviceGetLinkCapSta(virPCIDevicePtr dev,
 }


+int virPCIGetHeaderType(virPCIDevicePtr dev, int *hdrType)
+{
+    int fd;
+    uint8_t type;
+
+    *hdrType = -1;
+
+    if ((fd = virPCIDeviceConfigOpen(dev, true)) < 0)
+        return -1;
+
+    type = virPCIDeviceRead8(dev, fd, PCI_HEADER_TYPE);
+
+    virPCIDeviceConfigClose(dev, fd);
+
+    type &= PCI_HEADER_TYPE_MASK;
+    if (type >= VIR_PCI_HEADER_LAST) {
+        virReportError(VIR_ERR_INTERNAL_ERROR,
+                       _("Unknown PCI header type '%d'"), type);
+        return -1;
+    }
+
+    *hdrType = type;
+
+    return 0;
+}
+
+
 void
 virPCIEDeviceInfoFree(virPCIEDeviceInfoPtr dev)
 {
--- a/src/util/virpci.h
+++ b/src/util/virpci.h
@ -62,6 +62,16 @@ typedef enum {

 VIR_ENUM_DECL(virPCIELinkSpeed)

+typedef enum {
+    VIR_PCI_HEADER_ENDPOINT = 0,
+    VIR_PCI_HEADER_PCI_BRIDGE,
+    VIR_PCI_HEADER_CARDBUS_BRIDGE,
+
+    VIR_PCI_HEADER_LAST
+} virPCIHeaderType;
+
+VIR_ENUM_DECL(virPCIHeader)
+
 typedef struct _virPCIELink virPCIELink;
 typedef virPCIELink *virPCIELinkPtr;
 struct _virPCIELink {
@ -223,6 +233,8 @@ int virPCIDeviceGetLinkCapSta(virPCIDevicePtr dev,
                              unsigned int *sta_speed,
                              unsigned int *sta_width);

+int virPCIGetHeaderType(virPCIDevicePtr dev, int *hdrType);
+
 void virPCIEDeviceInfoFree(virPCIEDeviceInfoPtr dev);

 #endif /* __VIR_PCI_H__ */
--- a/tests/nodedevschemadata/pci_0000_00_02_0_header_type.xml
+++ b/tests/nodedevschemadata/pci_0000_00_02_0_header_type.xml
@ -0,0 +1,15 @@
+<device>
+  <name>pci_0000_00_02_0</name>
+  <parent>computer</parent>
+  <capability type='pci'>
+    <domain>0</domain>
+    <bus>0</bus>
+    <slot>2</slot>
+    <function>0</function>
+    <product id='0x0416'>4th Gen Core Processor Integrated Graphics Controller</product>
+    <vendor id='0x8086'>Intel Corporation</vendor>
+    <iommuGroup number='1'>
+      <address domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
+    </iommuGroup>
+  </capability>
+</device>
--- a/tests/nodedevschemadata/pci_0000_00_1c_0_header_type.xml
+++ b/tests/nodedevschemadata/pci_0000_00_1c_0_header_type.xml
@ -0,0 +1,20 @@
+<device>
+  <name>pci_0000_00_1c_0</name>
+  <parent>computer</parent>
+  <capability type='pci'>
+    <domain>0</domain>
+    <bus>0</bus>
+    <slot>28</slot>
+    <function>0</function>
+    <product id='0x8c10'>8 Series/C220 Series Chipset Family PCI Express Root Port #1</product>
+    <vendor id='0x8086'>Intel Corporation</vendor>
+    <iommuGroup number='8'>
+      <address domain='0x0000' bus='0x00' slot='0x1c' function='0x0'/>
+    </iommuGroup>
+    <capability type='pci-bridge'/>
+    <pci-express>
+      <link validity='cap' port='1' speed='5' width='1'/>
+      <link validity='sta' speed='2.5' width='1'/>
+    </pci-express>
+  </capability>
+</device>
--- a/tests/nodedevxml2xmltest.c
+++ b/tests/nodedevxml2xmltest.c
@ -91,6 +91,8 @@ mymain(void)
    DO_TEST("usb_device_1d6b_1_0000_00_1d_0");
    DO_TEST("pci_8086_4238_pcie_wireless");
    DO_TEST("pci_8086_0c0c_snd_hda_intel");
+    DO_TEST("pci_0000_00_02_0_header_type");
+    DO_TEST("pci_0000_00_1c_0_header_type");

    return ret == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
 }