[RFC PATCH 5/7] qemu: add support to TDVF firmware loader

[Zhenzhong Duan <zhenzhong.duan@xxxxxxxxx>]

TDX guest need a specific firmware TDVF to bootup, add a new element
in TrustDomain element for that purpose, like below:

<TrustDomain type='tdx'>
   <policy>0x0001</policy>
   <loader>/path/to/TDVF-binary</loader>
</TrustDomain>

Qemu command line looks like:

$QEMU ... \
  -device loader,file= /path/to/TDVF-binary,id=fd0

Signed-off-by: Zhenzhong Duan <zhenzhong.duan@xxxxxxxxx>
---
 docs/schemas/domaincommon.rng                   | 3 +++
 src/conf/domain_conf.c                          | 6 ++++++
 src/conf/domain_conf.h                          | 1 +
 src/qemu/qemu_command.c                         | 4 ++++
 tests/genericxml2xmlindata/trust-domain-tdx.xml | 1 +
 tests/qemuxml2argvdata/trust-domain-tdx.xml     | 1 +
 6 files changed, 16 insertions(+)

diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
index 2b39a01e84..b439012648 100644
--- a/docs/schemas/domaincommon.rng
+++ b/docs/schemas/domaincommon.rng
@@ -530,6 +530,9 @@
         <element name="policy">
           <ref name="hexuint"/>
         </element>
+        <element name="loader">
+          <data type="string"/>
+        </element>
       </interleave>
     </element>
   </define>
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index a51db088c1..0513d6d016 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -3515,6 +3515,7 @@ virDomainTDXDefFree(virDomainTDXDef *def)
     if (!def)
         return;
 
+    g_free(def->loader);
     g_free(def);
 }
 
@@ -14849,6 +14850,7 @@ virDomainTDXDefParseXML(xmlNodePtr tdxNode,
     }
 
     def->policy = policy;
+    def->loader = virXPathString("string(./loader)", ctxt);
 
     return def;
 
@@ -26950,6 +26952,10 @@ virDomainTDXDefFormat(virBuffer *buf, virDomainTDXDef *tdx)
     virBufferAsprintf(buf, "<TrustDomain type='tdx'>\n");
     virBufferAdjustIndent(buf, 2);
     virBufferAsprintf(buf, "<policy>0x%04x</policy>\n", tdx->policy);
+
+    if (tdx->loader)
+        virBufferEscapeString(buf, "<loader>%s</loader>\n", tdx->loader);
+
     virBufferAdjustIndent(buf, -2);
     virBufferAddLit(buf, "</TrustDomain>\n");
 }
diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index 7cb5061c8c..cabfc80b4b 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -2671,6 +2671,7 @@ typedef enum {
 struct _virDomainTDXDef {
     int sectype; /* enum virDomainTrustDomain */
     unsigned int policy; /* bit 0 set hint debug enabled, other bit reserved */
+    char *loader; /* patch for TDX TDVF firmware */
 };
 
 typedef enum {
diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 1e14c95a49..891d795b02 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -9885,6 +9885,10 @@ qemuBuildTDXCommandLine(virDomainObj *vm, virCommand *cmd,
 
     virCommandAddArg(cmd, "-object");
     virCommandAddArgBuffer(cmd, &buf);
+
+    virCommandAddArg(cmd, "-device");
+    virCommandAddArgFormat(cmd, "loader,id=fd0,file=%s", tdx->loader);
+
     return 0;
 }
 
diff --git a/tests/genericxml2xmlindata/trust-domain-tdx.xml b/tests/genericxml2xmlindata/trust-domain-tdx.xml
index 7a56cf0e92..7422f0c06f 100644
--- a/tests/genericxml2xmlindata/trust-domain-tdx.xml
+++ b/tests/genericxml2xmlindata/trust-domain-tdx.xml
@@ -16,6 +16,7 @@
   </devices>
   <TrustDomain type='tdx'>
     <policy>0x0001</policy>
+    <loader>/path/to/TDVF-binary</loader>
   </TrustDomain>
 </domain>
 
diff --git a/tests/qemuxml2argvdata/trust-domain-tdx.xml b/tests/qemuxml2argvdata/trust-domain-tdx.xml
index e0f0b77866..1d8ad45c4c 100644
--- a/tests/qemuxml2argvdata/trust-domain-tdx.xml
+++ b/tests/qemuxml2argvdata/trust-domain-tdx.xml
@@ -32,5 +32,6 @@
   </devices>
   <TrustDomain type='tdx'>
     <policy>0x0001</policy>
+    <loader>/path/to/TDVF-binary</loader>
   </TrustDomain>
 </domain>
-- 
2.25.1