[libvirt] [PATCH v2] virt-aa-helper: generate rules for gl enabled graphics devices

[Christian Ehrhardt]

This adds the virt-aa-helper support for gl enabled graphics devices to
generate rules for the needed rendernode paths.

Example in domain xml:
<graphics type='spice'>
  <gl enable='yes' rendernode='/dev/dri/bar'/>
</graphics>

results in:
  "/dev/dri/bar" rw,

Special cases are:
- multiple devices with rendernodes -> all are added
- non explicit rendernodes -> follow recently added virHostGetDRMRenderNode
- rendernode without opengl (in egl-headless for example) -> still add
  the node

Updates in V2:
- avoid leaking rendernode
- logically group patch hunks
- drop base /dev/dri access
- simplify detection of the need for a default rendernode
- add tests in tests/virt-aa-helper-test
- rebased to recent master

Fixes: https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/1757085

Signed-off-by: Christian Ehrhardt <christian.ehrhardt at canonical.com>
---
 src/security/virt-aa-helper.c | 12 ++++++++++++
 tests/virt-aa-helper-test     |  6 ++++++
 2 files changed, 18 insertions(+)

diff --git a/src/security/virt-aa-helper.c b/src/security/virt-aa-helper.c
index 64a425671d..a84dd5a8c9 100644
--- a/src/security/virt-aa-helper.c
+++ b/src/security/virt-aa-helper.c
@@ -1062,6 +1062,18 @@ get_files(vahControl * ctl)
     for (i = 0; i < ctl->def->ngraphics; i++) {
         virDomainGraphicsDefPtr graphics = ctl->def->graphics[i];
         size_t n;
+        const char *rendernode = virDomainGraphicsGetRenderNode(graphics);
+
+        if (rendernode)
+            vah_add_file(&buf, rendernode, "rw");
+        else
+            if (virDomainGraphicsNeedsAutoRenderNode(graphics)) {
+                char * defaultRenderNode = virHostGetDRMRenderNode();
+                if (defaultRenderNode) {
+                    vah_add_file(&buf, defaultRenderNode, "rw");
+                    VIR_FREE(defaultRenderNode);
+            }
+        }
 
         for (n = 0; n < graphics->nListens; n++) {
             virDomainGraphicsListenDef listenObj = graphics->listens[n];
diff --git a/tests/virt-aa-helper-test b/tests/virt-aa-helper-test
index fb400574dc..6e674bfe5c 100755
--- a/tests/virt-aa-helper-test
+++ b/tests/virt-aa-helper-test
@@ -378,6 +378,12 @@ testme "0" "input dev passthrough" "-r -u $valid_uuid" "$test_xml" "$disk2.*rw,$
 sed -e "s,###UUID###,$uuid,g" -e "s,###DISK###,$disk1,g" -e "s,<memory>524288</memory>,<memory>1048576</memory>,g" -e "s,</devices>,<memory model='nvdimm'><source><path>$disk2</path></source><target><size unit='KiB'>524288</size><node>0</node></target></memory></devices>,g" "$template_xml" > "$test_xml"
 testme "0" "nvdimm" "-r -u $valid_uuid" "$test_xml" "$disk2.*rw,$"
 
+sed -e "s,###UUID###,$uuid,g" -e "s,###DISK###,$disk1,g" -e "s,</devices>,<graphics type='egl-headless'><gl rendernode='/dev/dri/testegl1'/></graphics></devices>,g" "$template_xml" > "$test_xml"
+testme "0" "dri egl" "-r -u $valid_uuid" "$test_xml" "/dev/dri/testegl1.*rw,$"
+
+sed -e "s,###UUID###,$uuid,g" -e "s,###DISK###,$disk1,g" -e "s,</devices>,<graphics type='spice'><gl enable='yes' rendernode='/dev/dri/testegl2'/></graphics></devices>,g" "$template_xml" > "$test_xml"
+testme "0" "dri spice" "-r -u $valid_uuid" "$test_xml" "/dev/dri/testegl2.*rw,$"
+
 testme "0" "help" "-h"
 
 echo "" >$output
-- 
2.17.1