From 0d210c47f94e91da09bb1a4acd7e651f8bc7601f Mon Sep 17 00:00:00 2001
From: Laine Stump <laine@laine.org>
Date: Mon, 23 Nov 2015 14:50:31 -0500
Subject: [PATCH] conf: support reporting maxCount attribute for
 virtual_functions cap

Report the maximum possible number of VFs for an SRIOV PF, like this:

   <capability type='virtual_functions' maxCount='7'>
      ...
   </capability>

I've just discovered that the virtual_functions and physical_functions
capabilities are not supported in the virNodeDeviceParse functions,
only in virNodeDeviceFormat (I suppose because they are only reported,
not set from XML). This should probably be remedied, but is less
immediately useful than the current patch.
---
 docs/formatnode.html.in     | 11 ++++++++++-
 src/conf/node_device_conf.c | 32 ++++++++++++++++++++------------
 src/conf/node_device_conf.h |  1 +
 3 files changed, 31 insertions(+), 13 deletions(-)

diff --git a/docs/formatnode.html.in b/docs/formatnode.html.in
index ed00af59d4..6c12227b89 100644
--- a/docs/formatnode.html.in
+++ b/docs/formatnode.html.in
@@ -108,7 +108,16 @@
                 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.
+                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>numa</code></dt>
               <dd>
diff --git a/src/conf/node_device_conf.c b/src/conf/node_device_conf.c
index e6f3f272e0..c04739f901 100644
--- a/src/conf/node_device_conf.c
+++ b/src/conf/node_device_conf.c
@@ -361,19 +361,27 @@ char *virNodeDeviceDefFormat(const virNodeDeviceDef *def)
                 virBufferAddLit(&buf, "</capability>\n");
             }
             if (data->pci_dev.flags & VIR_NODE_DEV_CAP_FLAG_PCI_VIRTUAL_FUNCTION) {
-                virBufferAddLit(&buf, "<capability type='virt_functions'>\n");
-                virBufferAdjustIndent(&buf, 2);
-                for (i = 0; i < data->pci_dev.num_virtual_functions; i++) {
-                    virBufferAsprintf(&buf,
-                                      "<address domain='0x%.4x' bus='0x%.2x' "
-                                      "slot='0x%.2x' function='0x%.1x'/>\n",
-                                      data->pci_dev.virtual_functions[i]->domain,
-                                      data->pci_dev.virtual_functions[i]->bus,
-                                      data->pci_dev.virtual_functions[i]->slot,
-                                      data->pci_dev.virtual_functions[i]->function);
+                virBufferAddLit(&buf, "<capability type='virt_functions'");
+                if (data->pci_dev.max_virtual_functions)
+                    virBufferAsprintf(&buf, " maxCount='%u'",
+                                      data->pci_dev.max_virtual_functions);
+                if (data->pci_dev.num_virtual_functions == 0) {
+                    virBufferAddLit(&buf, "/>\n");
+                } else {
+                    virBufferAddLit(&buf, ">\n");
+                    virBufferAdjustIndent(&buf, 2);
+                    for (i = 0; i < data->pci_dev.num_virtual_functions; i++) {
+                        virBufferAsprintf(&buf,
+                                          "<address domain='0x%.4x' bus='0x%.2x' "
+                                          "slot='0x%.2x' function='0x%.1x'/>\n",
+                                          data->pci_dev.virtual_functions[i]->domain,
+                                          data->pci_dev.virtual_functions[i]->bus,
+                                          data->pci_dev.virtual_functions[i]->slot,
+                                          data->pci_dev.virtual_functions[i]->function);
+                    }
+                    virBufferAdjustIndent(&buf, -2);
+                    virBufferAddLit(&buf, "</capability>\n");
                 }
-                virBufferAdjustIndent(&buf, -2);
-                virBufferAddLit(&buf, "</capability>\n");
             }
             if (data->pci_dev.nIommuGroupDevices) {
                 virBufferAsprintf(&buf, "<iommuGroup number='%d'>\n",
diff --git a/src/conf/node_device_conf.h b/src/conf/node_device_conf.h
index 7dd39ca963..d0071867cc 100644
--- a/src/conf/node_device_conf.h
+++ b/src/conf/node_device_conf.h
@@ -112,6 +112,7 @@ typedef struct _virNodeDevCapData {
             virPCIDeviceAddressPtr physical_function;
             virPCIDeviceAddressPtr *virtual_functions;
             size_t num_virtual_functions;
+            unsigned int max_virtual_functions;
             unsigned int flags;
             virPCIDeviceAddressPtr *iommuGroupDevices;
             size_t nIommuGroupDevices;
-- 
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