xml: allow scaled memory on input

Output is still in kibibytes, but input can now be in different
scales for ease of typing.

* src/conf/domain_conf.c (virDomainParseMemory): New helper.
(virDomainDefParseXML): Use it when parsing.
* docs/schemas/domaincommon.rng: Expand XML; rename memoryKBElement
to memoryElement and update callers.
* docs/formatdomain.html.in (elementsMemoryAllocation): Document
scaling.
* tests/qemuxml2argvdata/qemuxml2argv-memtune.xml: Adjust test.
* tests/qemuxml2xmltest.c: Likewise.
* tests/qemuxml2xmloutdata/qemuxml2xmlout-memtune.xml: New file.

docs/formatdomain.html.in

@@ -415,8 +415,8 @@
 <pre>
 &lt;domain&gt;
   ...
-  &lt;memory&gt;524288&lt;/memory&gt;
+  &lt;memory unit='KiB'&gt;524288&lt;/memory&gt;
-  &lt;currentMemory&gt;524288&lt;/currentMemory&gt;
+  &lt;currentMemory unit='KiB'&gt;524288&lt;/currentMemory&gt;
   ...
 &lt;/domain&gt;
 </pre>
@@ -424,12 +424,31 @@
     <dl>
       <dt><code>memory</code></dt>
       <dd>The maximum allocation of memory for the guest at boot time.
-        The units for this value are kibibytes (i.e. blocks of 1024 bytes)</dd>
+        The units for this value are determined by the optional
+        atttribute <code>unit</code>, which defaults to "KiB"
+        (kibibytes, 2<sup>10</sup> or blocks of 1024 bytes).  Valid
+        units are "b" or "bytes" for bytes, "KB" for kilobytes
+        (10<sup>3</sup> or 1,000 bytes), "k" or "KiB" for kibibytes
+        (1024 bytes), "MB" for megabytes (10<sup>6</sup> or 1,000,000
+        bytes), "M" or "MiB" for mebibytes (2<sup>20</sup> or
+        1,048,576 bytes), "GB" for gigabytes (10<sup>9</sup> or
+        1,000,000,000 bytes), "G" or "GiB" for gibibytes
+        (2<sup>30</sup> or 1,073,741,824 bytes), "TB" for terabytes
+        (10<sup>12</sup> or 1,000,000,000,000 bytes), or "T" or "TiB"
+        for tebibytes (2<sup>40</sup> or 1,099,511,627,776 bytes).
+        However, the value will be rounded up to the nearest kibibyte
+        by libvirt, and may be further rounded to the granularity
+        supported by the hypervisor.  Some hypervisors also enforce a
+        minimum, such as
+        4000KiB. <span class='since'><code>unit</code> since
+        0.9.11</span></dd>
       <dt><code>currentMemory</code></dt>
       <dd>The actual allocation of memory for the guest. This value can
         be less than the maximum allocation, to allow for ballooning
         up the guests memory on the fly. If this is omitted, it defaults
-        to the same value as the <code>memory</code> element</dd>
+        to the same value as the <code>memory</code> element.
+        The <code>unit</code> attribute behaves the same as
+        for <code>memory</code>.</dd>
     </dl>
 
 
@@ -460,10 +479,10 @@
 &lt;domain&gt;
   ...
   &lt;memtune&gt;
-    &lt;hard_limit&gt;1048576&lt;/hard_limit&gt;
+    &lt;hard_limit unit='G'&gt;1&lt;/hard_limit&gt;
-    &lt;soft_limit&gt;131072&lt;/soft_limit&gt;
+    &lt;soft_limit unit='M'&gt;128&lt;/soft_limit&gt;
-    &lt;swap_hard_limit&gt;2097152&lt;/swap_hard_limit&gt;
+    &lt;swap_hard_limit unit='G'&gt;2&lt;/swap_hard_limit&gt;
-    &lt;min_guarantee&gt;65536&lt;/min_guarantee&gt;
+    &lt;min_guarantee unit='bytes'&gt;67108864&lt;/min_guarantee&gt;
   &lt;/memtune&gt;
   ...
 &lt;/domain&gt;
@@ -477,7 +496,13 @@
         parameters are applied to the QEMU process as a whole. Thus, when
         counting them, one needs to add up guest RAM, guest video RAM, and
         some memory overhead of QEMU itself. The last piece is hard to
-        determine so one needs guess and try.</dd>
+        determine so one needs guess and try.  For each tunable, it
+        is possible to designate which unit the number is in on
+        input, using the same values as
+        for <code>&lt;memory&gt;</code>.  For backwards
+        compatibility, output is always in
+        KiB.  <span class='since'><code>unit</code>
+        since 0.9.11</span></dd>
       <dt><code>hard_limit</code></dt>
       <dd> The optional <code>hard_limit</code> element is the maximum memory
         the guest can use. The units for this value are kibibytes (i.e. blocks

docs/schemas/domaincommon.rng

@@ -412,11 +412,11 @@
   <define name="resources">
     <interleave>
       <element name="memory">
-        <ref name='memoryKBElement'/>
+        <ref name='scaledInteger'/>
       </element>
       <optional>
         <element name="currentMemory">
-          <ref name='memoryKBElement'/>
+          <ref name='scaledInteger'/>
         </element>
       </optional>
       <optional>
@@ -461,25 +461,25 @@
           <!-- Maximum memory the VM can use -->
           <optional>
             <element name="hard_limit">
-              <ref name='memoryKBElement'/>
+              <ref name='scaledInteger'/>
             </element>
           </optional>
           <!-- Minimum memory ascertained for the VM during contention -->
           <optional>
             <element name="soft_limit">
-              <ref name='memoryKBElement'/>
+              <ref name='scaledInteger'/>
             </element>
           </optional>
           <!-- Minimum amount of memory required to start the VM -->
           <optional>
             <element name="min_guarantee">
-              <ref name='memoryKBElement'/>
+              <ref name='scaledInteger'/>
             </element>
           </optional>
           <!-- Maximum swap area the VM can use -->
           <optional>
             <element name="swap_hard_limit">
-              <ref name='memoryKBElement'/>
+              <ref name='scaledInteger'/>
             </element>
           </optional>
         </element>
@@ -3132,17 +3132,6 @@
       <param name="pattern">[0-9]+</param>
     </data>
   </define>
-  <!-- Memory as an element, with optional unit attribute -->
-  <define name='memoryKBElement'>
-    <optional>
-      <attribute name='unit'>
-        <value>KiB</value>
-      </attribute>
-    </optional>
-    <data type='unsignedInt'>
-      <param name='pattern'>[0-9]+</param>
-    </data>
-  </define>
   <define name="domainName">
     <data type="string">
       <!-- Use literal newline instead of \n for bug in libxml2 2.7.6 -->

src/conf/domain_conf.c

@@ -7491,6 +7491,60 @@ static int virDomainDefMaybeAddController(virDomainDefPtr def,
     return 0;
 }
 
+
+/* Parse a memory element located at XPATH within CTXT, and store the
+ * result into MEM.  If REQUIRED, then the value must exist;
+ * otherwise, the value is optional.  The value is in blocks of 1024.
+ * Return 0 on success, -1 on failure after issuing error.  */
+static int
+virDomainParseMemory(const char *xpath, xmlXPathContextPtr ctxt,
+                     unsigned long long *mem, bool required)
+{
+    char *xpath_full = NULL;
+    char *unit = NULL;
+    int ret = -1;
+    unsigned long long bytes;
+    unsigned long long max;
+
+    *mem = 0;
+    if (virAsprintf(&xpath_full, "string(%s)", xpath) < 0) {
+        virReportOOMError();
+        goto cleanup;
+    }
+    if (virXPathULongLong(xpath_full, ctxt, &bytes) < 0) {
+        if (required)
+            virDomainReportError(VIR_ERR_XML_ERROR,
+                                 "%s", _("missing memory element"));
+        else
+            ret = 0;
+        goto cleanup;
+    }
+    VIR_FREE(xpath_full);
+
+    if (virAsprintf(&xpath_full, "string(%s/@unit)", xpath) < 0) {
+        virReportOOMError();
+        goto cleanup;
+    }
+    unit = virXPathString(xpath_full, ctxt);
+    /* On 32-bit machines, our bound is 0xffffffff * KiB. On 64-bit
+     * machines, our bound is off_t (2^63).  */
+    if (sizeof(unsigned long) < sizeof(long long))
+        max = 1024ull * ULONG_MAX;
+    else
+        max = LLONG_MAX;
+    if (virScaleInteger(&bytes, unit, 1024, max) < 0)
+        goto cleanup;
+
+    /* Yes, we really do use kibibytes for our internal sizing.  */
+    *mem = VIR_DIV_UP(bytes, 1024);
+    ret = 0;
+cleanup:
+    VIR_FREE(xpath_full);
+    VIR_FREE(unit);
+    return ret;
+}
+
+
 static virDomainDefPtr virDomainDefParseXML(virCapsPtr caps,
                                             xmlDocPtr xml,
                                             xmlNodePtr root,
@@ -7614,22 +7668,21 @@ static virDomainDefPtr virDomainDefParseXML(virCapsPtr caps,
         goto error;
 
     /* Extract domain memory */
-    if (virXPathULongLong("string(./memory[1])", ctxt,
+    if (virDomainParseMemory("./memory[1]", ctxt,
-                          &def->mem.max_balloon) < 0) {
+                             &def->mem.max_balloon, true) < 0)
-        virDomainReportError(VIR_ERR_INTERNAL_ERROR,
-                             "%s", _("missing memory element"));
         goto error;
-    }
 
-    if (virXPathULongLong("string(./currentMemory[1])", ctxt,
+    if (virDomainParseMemory("./currentMemory[1]", ctxt,
-                          &def->mem.cur_balloon) < 0)
+                             &def->mem.cur_balloon, false) < 0)
-        def->mem.cur_balloon = def->mem.max_balloon;
+        goto error;
 
     if (def->mem.cur_balloon > def->mem.max_balloon) {
         virDomainReportError(VIR_ERR_XML_ERROR,
                              _("current memory '%lluk' exceeds maximum '%lluk'"),
                              def->mem.cur_balloon, def->mem.max_balloon);
         goto error;
+    } else if (def->mem.cur_balloon == 0) {
+        def->mem.cur_balloon = def->mem.max_balloon;
     }
 
     node = virXPathNode("./memoryBacking/hugepages", ctxt);
@@ -7668,21 +7721,21 @@ static virDomainDefPtr virDomainDefParseXML(virCapsPtr caps,
     VIR_FREE(nodes);
 
     /* Extract other memory tunables */
-    if (virXPathULongLong("string(./memtune/hard_limit)", ctxt,
+    if (virDomainParseMemory("./memtune/hard_limit[1]", ctxt,
-                          &def->mem.hard_limit) < 0)
+                             &def->mem.hard_limit, false) < 0)
-        def->mem.hard_limit = 0;
+        goto error;
 
-    if (virXPathULongLong("string(./memtune/soft_limit[1])", ctxt,
+    if (virDomainParseMemory("./memtune/soft_limit[1]", ctxt,
-                          &def->mem.soft_limit) < 0)
+                             &def->mem.soft_limit, false) < 0)
-        def->mem.soft_limit = 0;
+        goto error;
 
-    if (virXPathULongLong("string(./memtune/min_guarantee[1])", ctxt,
+    if (virDomainParseMemory("./memtune/min_guarantee[1]", ctxt,
-                          &def->mem.min_guarantee) < 0)
+                             &def->mem.min_guarantee, false) < 0)
-        def->mem.min_guarantee = 0;
+        goto error;
 
-    if (virXPathULongLong("string(./memtune/swap_hard_limit[1])", ctxt,
+    if (virDomainParseMemory("./memtune/swap_hard_limit[1]", ctxt,
-                          &def->mem.swap_hard_limit) < 0)
+                             &def->mem.swap_hard_limit, false) < 0)
-        def->mem.swap_hard_limit = 0;
+        goto error;
 
     n = virXPathULong("string(./vcpu[1])", ctxt, &count);
     if (n == -2) {

tests/qemuxml2argvdata/qemuxml2argv-memtune.xml

@@ -1,12 +1,12 @@
 <domain type='qemu'>
   <name>QEMUGuest1</name>
   <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
-  <memory unit='KiB'>219136</memory>
+  <memory unit='MiB'>214</memory>
   <currentMemory unit='KiB'>219136</currentMemory>
   <memtune>
     <hard_limit unit='KiB'>512000</hard_limit>
-    <soft_limit unit='KiB'>128000</soft_limit>
+    <soft_limit unit='bytes'>131071999</soft_limit>
-    <swap_hard_limit unit='KiB'>1024000</swap_hard_limit>
+    <swap_hard_limit unit='KB'>1048576</swap_hard_limit>
   </memtune>
   <vcpu>1</vcpu>
   <os>

tests/qemuxml2xmloutdata/qemuxml2xmlout-memtune.xml

@@ -0,0 +1,31 @@
+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>219136</memory>
+  <currentMemory unit='KiB'>219136</currentMemory>
+  <memtune>
+    <hard_limit unit='KiB'>512000</hard_limit>
+    <soft_limit unit='KiB'>128000</soft_limit>
+    <swap_hard_limit unit='KiB'>1024000</swap_hard_limit>
+  </memtune>
+  <vcpu>1</vcpu>
+  <os>
+    <type arch='i686' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/bin/qemu</emulator>
+    <disk type='block' device='disk'>
+      <source dev='/dev/HostVG/QEMUGuest1'/>
+      <target dev='hda' bus='ide'/>
+      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
+    </disk>
+    <controller type='usb' index='0'/>
+    <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
+  </devices>
+</domain>

tests/qemuxml2xmltest.c

@@ -195,7 +195,7 @@ mymain(void)
     DO_TEST("pci-rom");
 
     DO_TEST("encrypted-disk");
-    DO_TEST("memtune");
+    DO_TEST_DIFFERENT("memtune");
     DO_TEST("blkiotune");
     DO_TEST("blkiotune-device");
     DO_TEST("cputune");