[PATCH v2 4/8] domain_conf.c: XML parsing for VIR_DOMAIN_TPM_MODEL_SPAPR_PROXY

[Daniel Henrique Barboza]

Aside from trivial XML parsing/format changes, this patch adds
additional rules for TPM device support to better accomodate
all the available scenarios with the new TPM Proxy.

The changes make no impact to existing domains. This means that
the scenario of a domain with a single TPM device is still
supported in the same way.  The restriction of multiple TPM devices
got alleviated to allow a TPM Proxy device to be added together
with a TPM device in the same domain. All other combinations
are still forbidden.

To summarize, after this patch, the following combinations in the same
domain are valid:

- a single TPM device
- a single TPM Proxy device
- a single TPM + single TPM Proxy devices

These combinations in the same domain are NOT allowed:

- 2 or more TPM devices
- 2 or more TPM Proxy devices

Signed-off-by: Daniel Henrique Barboza <danielhb413 at gmail.com>
---
 src/conf/domain_conf.c | 47 ++++++++++++++++++++++++++++++++++++++----
 1 file changed, 43 insertions(+), 4 deletions(-)

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 01a32f62d1..33b7d69318 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -13730,6 +13730,14 @@ virDomainTPMDefParseXML(virDomainXMLOptionPtr xmlopt,
         goto error;
     }
 
+    /* TPM Proxy devices have 'passthrough' backend */
+    if (def->model == VIR_DOMAIN_TPM_MODEL_SPAPR_PROXY &&
+        def->type != VIR_DOMAIN_TPM_TYPE_PASSTHROUGH) {
+        virReportError(VIR_ERR_XML_ERROR, "%s",
+                       _("'Passthrough' backend is required for TPM Proxy devices"));
+        goto error;
+    }
+
     if (virDomainDeviceInfoParseXML(xmlopt, node, &def->info, flags) < 0)
         goto error;
 
@@ -21972,15 +21980,41 @@ virDomainDefParseXML(xmlDocPtr xml,
     if ((n = virXPathNodeSet("./devices/tpm", ctxt, &nodes)) < 0)
         goto error;
 
-    if (n > 1) {
+    if (n > 2) {
         virReportError(VIR_ERR_XML_ERROR, "%s",
-                       _("only a single TPM device is supported"));
+                       _("a maximum of two TPM devices is supported, one of "
+                         "them being a TPM Proxy device"));
         goto error;
     }
 
     if (n > 0) {
-        if (!(def->tpm = virDomainTPMDefParseXML(xmlopt, nodes[0], ctxt, flags)))
-            goto error;
+        for (i = 0; i < n; i++) {
+            virDomainTPMDefPtr dev = virDomainTPMDefParseXML(xmlopt, nodes[i], ctxt, flags);
+
+            if (!dev)
+                goto error;
+
+            /* TPM Proxy devices must be held in def->tpmproxy. Error
+             * out if there's a TPM Proxy declared already */
+            if (dev->model == VIR_DOMAIN_TPM_MODEL_SPAPR_PROXY) {
+                if (def->tpmproxy) {
+                    virReportError(VIR_ERR_XML_ERROR, "%s",
+                                   _("only a single TPM Proxy device is supported"));
+                    VIR_FREE(dev);
+                    goto error;
+                }
+                def->tpmproxy = g_steal_pointer(&dev);
+            } else {
+                /* all other TPM devices goes to def->tpm */
+                if (def->tpm) {
+                    virReportError(VIR_ERR_XML_ERROR, "%s",
+                                   _("only a single TPM non-proxy device is supported"));
+                    VIR_FREE(dev);
+                    goto error;
+                }
+                def->tpm = g_steal_pointer(&dev);
+            }
+        }
     }
     VIR_FREE(nodes);
 
@@ -29807,6 +29841,11 @@ virDomainDefFormatInternalSetRootName(virDomainDefPtr def,
             goto error;
     }
 
+    if (def->tpmproxy) {
+        if (virDomainTPMDefFormat(buf, def->tpmproxy, flags) < 0)
+            goto error;
+    }
+
     for (n = 0; n < def->ngraphics; n++) {
         if (virDomainGraphicsDefFormat(buf, def->graphics[n], flags) < 0)
             goto error;
-- 
2.26.2