[PATCH] ch: Support RNG device

[Stefan Kober]

Cloud Hypervisor supports virtio-rng devices and the configuration of
the randomness source (e.g. /dev/random or /dev/urandom).

This commit adds support for configuring the RNG device via libvirt for
the ch driver.

Signed-off-by: Stefan Kober <stefan.ko...@cyberus-technology.de>
---
 src/ch/ch_domain.c  |  8 +++++++-
 src/ch/ch_monitor.c | 41 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/src/ch/ch_domain.c b/src/ch/ch_domain.c
index c0c9acd85b..7231fdc49f 100644
--- a/src/ch/ch_domain.c
+++ b/src/ch/ch_domain.c
@@ -163,6 +163,7 @@ chValidateDomainDeviceDef(const virDomainDeviceDef *dev,
     case VIR_DOMAIN_DEVICE_CONTROLLER:
     case VIR_DOMAIN_DEVICE_CHR:
     case VIR_DOMAIN_DEVICE_HOSTDEV:
+    case VIR_DOMAIN_DEVICE_RNG:
         break;
 
     case VIR_DOMAIN_DEVICE_LEASE:
@@ -177,7 +178,6 @@ chValidateDomainDeviceDef(const virDomainDeviceDef *dev,
     case VIR_DOMAIN_DEVICE_SMARTCARD:
     case VIR_DOMAIN_DEVICE_MEMBALLOON:
     case VIR_DOMAIN_DEVICE_NVRAM:
-    case VIR_DOMAIN_DEVICE_RNG:
     case VIR_DOMAIN_DEVICE_SHMEM:
     case VIR_DOMAIN_DEVICE_TPM:
     case VIR_DOMAIN_DEVICE_PANIC:
@@ -218,6 +218,12 @@ chValidateDomainDeviceDef(const virDomainDeviceDef *dev,
         return -1;
     }
 
+    if (def->nrngs > 1) {
+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                       _("Only a single RNG device can be configured for this 
domain"));
+        return -1;
+    }
+
     if (def->nserials > 1) {
         virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
                        _("Only a single serial can be configured for this 
domain"));
diff --git a/src/ch/ch_monitor.c b/src/ch/ch_monitor.c
index 5a490b75f6..3d3b4cb87d 100644
--- a/src/ch/ch_monitor.c
+++ b/src/ch/ch_monitor.c
@@ -302,6 +302,44 @@ virCHMonitorBuildDisksJson(virJSONValue *content, 
virDomainDef *vmdef)
     return 0;
 }
 
+static int
+virCHMonitorBuildRngJson(virJSONValue *content, virDomainDef *vmdef)
+{
+    g_autoptr(virJSONValue) rng = virJSONValueNewObject();
+
+    if (vmdef->nrngs == 0) {
+        return 0;
+    }
+
+    if (vmdef->rngs[0]->model != VIR_DOMAIN_RNG_MODEL_VIRTIO) {
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                       _("Only virtio model is supported for RNG devices"));
+        return -1;
+    }
+
+    switch (vmdef->rngs[0]->backend) {
+    case VIR_DOMAIN_RNG_BACKEND_RANDOM:
+        if (virJSONValueObjectAppendString(rng, "src", 
vmdef->rngs[0]->source.file) < 0)
+            return -1;
+
+        if (virJSONValueObjectAppend(content, "rng", &rng) < 0)
+            return -1;
+
+        break;
+
+    case VIR_DOMAIN_RNG_BACKEND_EGD:
+    case VIR_DOMAIN_RNG_BACKEND_BUILTIN:
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                       _("Only RANDOM backend is supported for RNG devices"));
+        return -1;
+
+    case VIR_DOMAIN_RNG_BACKEND_LAST:
+        break;
+    }
+
+    return 0;
+}
+
 /**
  * virCHMonitorBuildNetJson:
  * @net: pointer to a guest network definition
@@ -501,6 +539,9 @@ virCHMonitorBuildVMJson(virCHDriver *driver, virDomainDef 
*vmdef,
     if (virCHMonitorBuildDisksJson(content, vmdef) < 0)
         return -1;
 
+    if (virCHMonitorBuildRngJson(content, vmdef) < 0)
+        return -1;
+
     if (virCHMonitorBuildDevicesJson(content, vmdef) < 0)
         return -1;
 
-- 
2.49.0