From 5c74cf1f440b19c05dd9dbd2ab22c217db959fcf Mon Sep 17 00:00:00 2001
From: Michal Privoznik <mprivozn@redhat.com>
Date: Thu, 9 Feb 2017 17:53:53 +0100
Subject: [PATCH] qemu: Allow @rendernode for virgl domains

When enabling virgl, qemu opens /dev/dri/render*. So far, we are
not allowing that in devices CGroup nor creating the file in
domain's namespace and thus requiring users to set the paths in
qemu.conf. This, however, is suboptimal as it allows access to
ALL qemu processes even those which don't have virgl configured.
Now that we have a way to specify render node that qemu will use
we can be more cautious and enable just that.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
---
 src/qemu/qemu_cgroup.c | 27 +++++++++++++++++++++++++++
 src/qemu/qemu_domain.c | 39 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 66 insertions(+)

diff --git a/src/qemu/qemu_cgroup.c b/src/qemu/qemu_cgroup.c
index 209cbc275a..f0729743ab 100644
--- a/src/qemu/qemu_cgroup.c
+++ b/src/qemu/qemu_cgroup.c
@@ -335,6 +335,28 @@ qemuTeardownHostdevCgroup(virDomainObjPtr vm,
     return ret;
 }
 
+
+static int
+qemuSetupGraphicsCgroup(virDomainObjPtr vm,
+                        virDomainGraphicsDefPtr gfx)
+{
+    qemuDomainObjPrivatePtr priv = vm->privateData;
+    const char *rendernode = gfx->data.spice.rendernode;
+    int ret;
+
+    if (gfx->type != VIR_DOMAIN_GRAPHICS_TYPE_SPICE ||
+        gfx->data.spice.gl != VIR_TRISTATE_BOOL_YES ||
+        !rendernode)
+        return 0;
+
+    ret = virCgroupAllowDevicePath(priv->cgroup, rendernode,
+                                   VIR_CGROUP_DEVICE_RW, false);
+    virDomainAuditCgroupPath(vm, priv->cgroup, "allow", rendernode,
+                             "rw", ret == 0);
+    return ret;
+}
+
+
 static int
 qemuSetupBlkioCgroup(virDomainObjPtr vm)
 {
@@ -604,6 +626,11 @@ qemuSetupDevicesCgroup(virQEMUDriverPtr driver,
             goto cleanup;
     }
 
+    for (i = 0; i < vm->def->ngraphics; i++) {
+        if (qemuSetupGraphicsCgroup(vm, vm->def->graphics[i]) < 0)
+            goto cleanup;
+    }
+
     for (i = 0; i < vm->def->ninputs; i++) {
         if (qemuSetupInputCgroup(vm, vm->def->inputs[i]) < 0)
             goto cleanup;
diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index 92a9a105c3..ea4b28288e 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -7526,6 +7526,42 @@ qemuDomainSetupTPM(virQEMUDriverPtr driver ATTRIBUTE_UNUSED,
 }
 
 
+static int
+qemuDomainSetupGraphics(virQEMUDriverPtr driver ATTRIBUTE_UNUSED,
+                        virDomainGraphicsDefPtr gfx,
+                        const char *devPath)
+{
+    const char *rendernode = gfx->data.spice.rendernode;
+
+    if (gfx->type != VIR_DOMAIN_GRAPHICS_TYPE_SPICE ||
+        gfx->data.spice.gl != VIR_TRISTATE_BOOL_YES ||
+        !rendernode)
+        return 0;
+
+    return qemuDomainCreateDevice(rendernode, devPath, false);
+}
+
+
+static int
+qemuDomainSetupAllGraphics(virQEMUDriverPtr driver,
+                           virDomainObjPtr vm,
+                           const char *devPath)
+{
+    size_t i;
+
+    VIR_DEBUG("Setting up graphics");
+    for (i = 0; i < vm->def->ngraphics; i++) {
+        if (qemuDomainSetupGraphics(driver,
+                                    vm->def->graphics[i],
+                                    devPath) < 0)
+            return -1;
+    }
+
+    VIR_DEBUG("Setup all graphics");
+    return 0;
+}
+
+
 static int
 qemuDomainSetupInput(virQEMUDriverPtr driver ATTRIBUTE_UNUSED,
                      virDomainInputDefPtr input,
@@ -7679,6 +7715,9 @@ qemuDomainBuildNamespace(virQEMUDriverPtr driver,
     if (qemuDomainSetupTPM(driver, vm, devPath) < 0)
         goto cleanup;
 
+    if (qemuDomainSetupAllGraphics(driver, vm, devPath) < 0)
+        goto cleanup;
+
     if (qemuDomainSetupAllInputs(driver, vm, devPath) < 0)
         goto cleanup;