conf: cpu: add limit for maxphysaddr

Add a limit attribute to restrict the maximum physical address bits
that would be used for the guest CPU:

   <cpu mode='host-passthrough'>
     <maxphysaddr mode='passthrough' limit='39'/>
   </cpu>

https://gitlab.com/libvirt/libvirt/-/issues/450
https://bugzilla.redhat.com/show_bug.cgi?id=2171860

Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>

diff --git a/docs/formatdomain.rst b/docs/formatdomain.rst
index cb3fe3dc1c33b95a621ad0c3ea826431c0bb3267..f5bbfdc20aef651cdae8210d7524260eb22d30bb 100644 (file)
--- a/docs/formatdomain.rst
+++ b/docs/formatdomain.rst
@@ -1374,7 +1374,7 @@ following collection of elements. :since:`Since 0.7.5`
 
    <cpu mode='host-passthrough' migratable='off'>
      <cache mode='passthrough'/>
-     <maxphysaddr mode='passthrough'/>
+     <maxphysaddr mode='passthrough' limit='39'/>
      <feature policy='disable' name='lahf_lm'/>
    ...
 
@@ -1644,6 +1644,11 @@ In case no restrictions need to be put on CPU model and its features, a simpler
       The ``bits`` attribute is mandatory if the ``mode`` attribute is set to
       ``emulate`` and specifies the virtual CPU address size in bits.
 
+   ``limit``
+     The ``limit`` attribute can be used to restrict the maximum value of
+     address bits for ``passthrough`` mode, i.e. in case the host CPU reports
+     more bits than that, ``limit`` is used. :since:`Since 9.3.0`
+
 Guest NUMA topology can be specified using the ``numa`` element. :since:`Since
 0.9.8`
 

diff --git a/src/conf/cpu_conf.c b/src/conf/cpu_conf.c
index 2b361d2c68dda5e7c1f8429a7b7cb3c73bfdd058..98adb0e5d5047f05c58b62ab3b722ceb1eb4e796 100644 (file)
--- a/src/conf/cpu_conf.c
+++ b/src/conf/cpu_conf.c
@@ -668,6 +668,17 @@ virCPUDefParseXML(xmlXPathContextPtr ctxt,
                           VIR_XML_PROP_NONNEGATIVE,
                           &def->addr->bits, -1) < 0)
             return -1;
+
+        if ((rv = virXMLPropUInt(maxphysaddrNode, "limit", 10,
+                                 VIR_XML_PROP_NONZERO,
+                                 &def->addr->limit)) < 0) {
+            return -1;
+        } else if (rv > 0 && def->addr->mode != VIR_CPU_MAX_PHYS_ADDR_MODE_PASSTHROUGH) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                           _("attribute 'limit' is only supported for maxphysaddr mode 'passthrough'"));
+            return -1;
+        }
+
     }
 
     *cpu = g_steal_pointer(&def);
@@ -843,6 +854,8 @@ virCPUDefFormatBuf(virBuffer *buf,
                           virCPUMaxPhysAddrModeTypeToString(def->addr->mode));
         if (def->addr->bits != -1)
             virBufferAsprintf(buf, " bits='%d'", def->addr->bits);
+        if (def->addr->limit > 0)
+            virBufferAsprintf(buf, " limit='%d'", def->addr->limit);
         virBufferAddLit(buf, "/>\n");
     }
 

diff --git a/src/conf/cpu_conf.h b/src/conf/cpu_conf.h
index 82083d668cf14b4d301e3cf12fecb0738e66efa1..3e4c53675c8610bcc292c27e3b41b0cf78241426 100644 (file)
--- a/src/conf/cpu_conf.h
+++ b/src/conf/cpu_conf.h
@@ -128,6 +128,7 @@ VIR_ENUM_DECL(virCPUMaxPhysAddrMode);
 typedef struct _virCPUMaxPhysAddrDef virCPUMaxPhysAddrDef;
 struct _virCPUMaxPhysAddrDef {
     int bits;           /* -1 for unspecified */
+    unsigned int limit; /* 0 for unspecified */
     virCPUMaxPhysAddrMode mode;
 };
 

diff --git a/src/conf/schemas/cputypes.rng b/src/conf/schemas/cputypes.rng
index 3e79bdd563e5f1dcf755eec8c1c7163d45b9ad9b..db1aa571582079a2680dc543e70f218fcda43b36 100644 (file)
--- a/src/conf/schemas/cputypes.rng
+++ b/src/conf/schemas/cputypes.rng
@@ -318,6 +318,11 @@
           <ref name="unsignedInt"/>
         </attribute>
       </optional>
+      <optional>
+        <attribute name="limit">
+          <ref name="unsignedInt"/>
+        </attribute>
+      </optional>
     </element>
   </define>
 

diff --git a/tests/qemuxml2argvdata/cpu-phys-bits-limit.xml b/tests/qemuxml2argvdata/cpu-phys-bits-limit.xml
new file mode 100644 (file)
index 0000000..aabfb77
--- /dev/null
+++ b/tests/qemuxml2argvdata/cpu-phys-bits-limit.xml
@@ -0,0 +1,20 @@
+<domain type='kvm'>
+  <name>foo</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>219136</memory>
+  <currentMemory unit='KiB'>219136</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='x86_64' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <cpu mode='host-passthrough'>
+    <maxphysaddr mode='passthrough' limit='39'/>
+  </cpu>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+  </devices>
+</domain>

diff --git a/tests/qemuxml2xmloutdata/cpu-phys-bits-limit.x86_64-latest.xml b/tests/qemuxml2xmloutdata/cpu-phys-bits-limit.x86_64-latest.xml
new file mode 100644 (file)
index 0000000..ced2d9c
--- /dev/null
+++ b/tests/qemuxml2xmloutdata/cpu-phys-bits-limit.x86_64-latest.xml
@@ -0,0 +1,31 @@
+<domain type='kvm'>
+  <name>foo</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>219136</memory>
+  <currentMemory unit='KiB'>219136</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='x86_64' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <cpu mode='host-passthrough' check='none' migratable='on'>
+    <maxphysaddr mode='passthrough' limit='39'/>
+  </cpu>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/bin/qemu-system-x86_64</emulator>
+    <controller type='usb' index='0' model='piix3-uhci'>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/>
+    </controller>
+    <controller type='pci' index='0' model='pci-root'/>
+    <input type='mouse' bus='ps2'/>
+    <input type='keyboard' bus='ps2'/>
+    <audio id='1' type='none'/>
+    <memballoon model='virtio'>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
+    </memballoon>
+  </devices>
+</domain>

diff --git a/tests/qemuxml2xmltest.c b/tests/qemuxml2xmltest.c
index b1bc6e9216d05513336965d615461d0c311dcb9f..598a8d90654a97bccef4c43855a5693df9102ac0 100644 (file)
--- a/tests/qemuxml2xmltest.c
+++ b/tests/qemuxml2xmltest.c
@@ -1247,6 +1247,8 @@ mymain(void)
 
     DO_TEST_CAPS_LATEST("crypto-builtin");
 
+    DO_TEST_CAPS_LATEST("cpu-phys-bits-limit");
+
  cleanup:
     qemuTestDriverFree(&driver);
     virFileWrapperClearPrefixes();