From: Michal Privoznik Date: Fri, 11 May 2018 13:08:53 +0000 (+0200) Subject: conf: Introduce memoryBacking/discard X-Git-Tag: v4.4.0-rc1~205 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2300c92fe0d596258ed2f7da1b867d0ce2112f90;p=thirdparty%2Flibvirt.git conf: Introduce memoryBacking/discard QEMU has possibility to call madvise(.., MADV_REMOVE) in some cases. Expose this feature to users by new element/attribute discard. Signed-off-by: Michal Privoznik Reviewed-by: Ján Tomko --- diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in index 072f9a0fdc..80172c18d0 100644 --- a/docs/formatdomain.html.in +++ b/docs/formatdomain.html.in @@ -1016,6 +1016,7 @@ <source type="file|anonymous"/> <access mode="shared|private"/> <allocation mode="immediate|ondemand"/> + <discard/> </memoryBacking> ... </domain> @@ -1070,6 +1071,14 @@ numa node by memAccess
allocation
Specify when allocate the memory
+
discard
+
When set and supported by hypervisor the memory + content is discarded just before guest shuts down (or + when DIMM module is unplugged). Please note that this is + just an optimization and is not guaranteed to work in + all cases (e.g. when hypervisor crashes). + Since 4.4.0 (QEMU/KVM only) +
@@ -1608,7 +1617,7 @@ <cpu> ... <numa> - <cell id='0' cpus='0-3' memory='512000' unit='KiB'/> + <cell id='0' cpus='0-3' memory='512000' unit='KiB' discard='yes'/> <cell id='1' cpus='4-7' memory='512000' unit='KiB' memAccess='shared'/> </numa> ... @@ -1634,6 +1643,13 @@ memAccess can control whether the memory is to be mapped as "shared" or "private". This is valid only for hugepages-backed memory and nvdimm modules. + + Each cell element can have an optional + discard attribute which fine tunes the discard + feature for given numa node as described under + Memory Backing. + Accepted values are yes and no. + Since 4.4.0

@@ -7883,7 +7899,7 @@ qemu-kvm -net nic,model=? /dev/null 

 ...
 <devices>
-  <memory model='dimm' access='private'>
+  <memory model='dimm' access='private' discard='yes'>
     <target>
       <size unit='KiB'>524287</size>
       <node>0</node>
@@ -7937,6 +7953,20 @@ qemu-kvm -net nic,model=? /dev/null
         

       
 
+      
discard

+      

+        

+          An optional attribute discard
+          (since 4.4.0) that provides
+          capability to fine tune discard of data on per module
+          basis. Accepted values are yes and
+          no. The feature is described here:
+          Memory Backing.
+          This attribute is allowed only for
+          model='dimm'.
+        

+      

+
       
source

       

         

diff --git a/docs/schemas/cputypes.rng b/docs/schemas/cputypes.rng
index c45b6dfb28..1f1e0e36d5 100644
--- a/docs/schemas/cputypes.rng
+++ b/docs/schemas/cputypes.rng
@@ -129,6 +129,11 @@
           
         
       
+      
+        
+          
+        
+      
       
         
           
diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
index 8c446ca418..13af5b74a4 100644
--- a/docs/schemas/domaincommon.rng
+++ b/docs/schemas/domaincommon.rng
@@ -633,6 +633,11 @@
                 
               
             
+            
+              
+                
+              
+            
           
         
       
@@ -5124,6 +5129,11 @@
           
         
       
+      
+        
+          
+        
+      
       
         
           
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 6786d81c9b..86229db654 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -5516,6 +5516,20 @@ virDomainVideoDefValidate(const virDomainVideoDef *video)
 }
 
 
+static int
+virDomainMemoryDefValidate(const virDomainMemoryDef *mem)
+{
+    if (mem->model == VIR_DOMAIN_MEMORY_MODEL_NVDIMM &&
+        mem->discard == VIR_TRISTATE_BOOL_YES) {
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                       _("discard is not supported for nvdimms"));
+        return -1;
+    }
+
+    return 0;
+}
+
+
 static int
 virDomainDeviceDefValidateInternal(const virDomainDeviceDef *dev,
                                    const virDomainDef *def)
@@ -5548,6 +5562,9 @@ virDomainDeviceDefValidateInternal(const virDomainDeviceDef *dev,
     case VIR_DOMAIN_DEVICE_VIDEO:
         return virDomainVideoDefValidate(dev->data.video);
 
+    case VIR_DOMAIN_DEVICE_MEMORY:
+        return virDomainMemoryDefValidate(dev->data.memory);
+
     case VIR_DOMAIN_DEVICE_LEASE:
     case VIR_DOMAIN_DEVICE_FS:
     case VIR_DOMAIN_DEVICE_INPUT:
@@ -5560,7 +5577,6 @@ virDomainDeviceDefValidateInternal(const virDomainDeviceDef *dev,
     case VIR_DOMAIN_DEVICE_SHMEM:
     case VIR_DOMAIN_DEVICE_TPM:
     case VIR_DOMAIN_DEVICE_PANIC:
-    case VIR_DOMAIN_DEVICE_MEMORY:
     case VIR_DOMAIN_DEVICE_IOMMU:
     case VIR_DOMAIN_DEVICE_NONE:
     case VIR_DOMAIN_DEVICE_LAST:
@@ -15673,6 +15689,16 @@ virDomainMemoryDefParseXML(virDomainXMLOptionPtr xmlopt,
     }
     VIR_FREE(tmp);
 
+    if ((tmp = virXMLPropString(memdevNode, "discard"))) {
+        if ((val = virTristateBoolTypeFromString(tmp)) <= 0) {
+            virReportError(VIR_ERR_XML_ERROR,
+                           _("invalid discard value '%s'"), tmp);
+            goto error;
+        }
+
+        def->discard = val;
+    }
+
     /* source */
     if ((node = virXPathNode("./source", ctxt)) &&
         virDomainMemorySourceDefParseXML(node, ctxt, def) < 0)
@@ -18999,6 +19025,9 @@ virDomainDefParseXML(xmlDocPtr xml,
     if (virXPathBoolean("boolean(./memoryBacking/locked)", ctxt))
         def->mem.locked = true;
 
+    if (virXPathBoolean("boolean(./memoryBacking/discard)", ctxt))
+        def->mem.discard = VIR_TRISTATE_BOOL_YES;
+
     /* Extract blkio cgroup tunables */
     if (virXPathUInt("string(./blkiotune/weight)", ctxt,
                      &def->blkio.weight) < 0)
@@ -25259,6 +25288,9 @@ virDomainMemoryDefFormat(virBufferPtr buf,
     if (def->access)
         virBufferAsprintf(buf, " access='%s'",
                           virDomainMemoryAccessTypeToString(def->access));
+    if (def->discard)
+        virBufferAsprintf(buf, " discard='%s'",
+                          virTristateBoolTypeToString(def->discard));
     virBufferAddLit(buf, ">\n");
     virBufferAdjustIndent(buf, 2);
 
@@ -26605,6 +26637,8 @@ virDomainMemtuneFormat(virBufferPtr buf,
     if (mem->allocation)
         virBufferAsprintf(&childBuf, "\n",
                           virDomainMemoryAllocationTypeToString(mem->allocation));
+    if (mem->discard)
+        virBufferAddLit(&childBuf, "\n");
 
     if (virXMLFormatElement(buf, "memoryBacking", NULL, &childBuf) < 0)
         goto cleanup;
diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index 15d228ba9e..07d04fb2f9 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -2105,6 +2105,7 @@ typedef enum {
 
 struct _virDomainMemoryDef {
     virDomainMemoryAccess access;
+    virTristateBool discard;
 
     /* source */
     virBitmapPtr sourceNodes;
@@ -2267,6 +2268,8 @@ struct _virDomainMemtune {
     int source; /* enum virDomainMemorySource */
     int access; /* enum virDomainMemoryAccess */
     int allocation; /* enum virDomainMemoryAllocation */
+
+    virTristateBool discard;
 };
 
 typedef struct _virDomainPowerManagement virDomainPowerManagement;
diff --git a/src/conf/numa_conf.c b/src/conf/numa_conf.c
index 9307dd93d3..97a3ca485d 100644
--- a/src/conf/numa_conf.c
+++ b/src/conf/numa_conf.c
@@ -77,6 +77,7 @@ struct _virDomainNuma {
         virBitmapPtr nodeset;   /* host memory nodes where this guest node resides */
         virDomainNumatuneMemMode mode;  /* memory mode selection */
         virDomainMemoryAccess memAccess; /* shared memory access configuration */
+        virTristateBool discard; /* discard-data for memory-backend-file */
 
         struct _virDomainNumaDistance {
             unsigned int value; /* locality value for node i->j or j->i */
@@ -947,6 +948,18 @@ virDomainNumaDefCPUParseXML(virDomainNumaPtr def,
             VIR_FREE(tmp);
         }
 
+        if ((tmp = virXMLPropString(nodes[i], "discard"))) {
+            if ((rc = virTristateBoolTypeFromString(tmp)) <= 0) {
+                virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                               _("Invalid 'discard' attribute value '%s'"),
+                               tmp);
+                goto cleanup;
+            }
+
+            def->mem_nodes[cur_cell].discard = rc;
+            VIR_FREE(tmp);
+        }
+
         /* Parse NUMA distances info */
         if (virDomainNumaDefNodeDistanceParseXML(def, ctxt, cur_cell) < 0)
                 goto cleanup;
@@ -967,6 +980,7 @@ virDomainNumaDefCPUFormatXML(virBufferPtr buf,
                              virDomainNumaPtr def)
 {
     virDomainMemoryAccess memAccess;
+    virTristateBool discard;
     char *cpustr;
     size_t ncells = virDomainNumaGetNodeCount(def);
     size_t i;
@@ -980,6 +994,7 @@ virDomainNumaDefCPUFormatXML(virBufferPtr buf,
         int ndistances;
 
         memAccess = virDomainNumaGetNodeMemoryAccessMode(def, i);
+        discard = virDomainNumaGetNodeDiscard(def, i);
 
         if (!(cpustr = virBitmapFormat(virDomainNumaGetNodeCpumask(def, i))))
             return -1;
@@ -994,6 +1009,10 @@ virDomainNumaDefCPUFormatXML(virBufferPtr buf,
             virBufferAsprintf(buf, " memAccess='%s'",
                               virDomainMemoryAccessTypeToString(memAccess));
 
+        if (discard)
+            virBufferAsprintf(buf, " discard='%s'",
+                              virTristateBoolTypeToString(discard));
+
         ndistances = def->mem_nodes[i].ndistances;
         if (ndistances == 0) {
             virBufferAddLit(buf, "/>\n");
@@ -1304,6 +1323,14 @@ virDomainNumaGetNodeMemoryAccessMode(virDomainNumaPtr numa,
 }
 
 
+virTristateBool
+virDomainNumaGetNodeDiscard(virDomainNumaPtr numa,
+                            size_t node)
+{
+    return numa->mem_nodes[node].discard;
+}
+
+
 unsigned long long
 virDomainNumaGetNodeMemorySize(virDomainNumaPtr numa,
                                size_t node)
diff --git a/src/conf/numa_conf.h b/src/conf/numa_conf.h
index 7947fdb219..85269be565 100644
--- a/src/conf/numa_conf.h
+++ b/src/conf/numa_conf.h
@@ -102,6 +102,9 @@ virBitmapPtr virDomainNumaGetNodeCpumask(virDomainNumaPtr numa,
 virDomainMemoryAccess virDomainNumaGetNodeMemoryAccessMode(virDomainNumaPtr numa,
                                                       size_t node)
     ATTRIBUTE_NONNULL(1);
+virTristateBool virDomainNumaGetNodeDiscard(virDomainNumaPtr numa,
+                                            size_t node)
+    ATTRIBUTE_NONNULL(1);
 unsigned long long virDomainNumaGetNodeMemorySize(virDomainNumaPtr numa,
                                                   size_t node)
     ATTRIBUTE_NONNULL(1);
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 5fea1bca41..d28a751ebd 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -750,6 +750,7 @@ virDomainNumaGetMaxCPUID;
 virDomainNumaGetMemorySize;
 virDomainNumaGetNodeCount;
 virDomainNumaGetNodeCpumask;
+virDomainNumaGetNodeDiscard;
 virDomainNumaGetNodeDistance;
 virDomainNumaGetNodeMemoryAccessMode;
 virDomainNumaGetNodeMemorySize;
diff --git a/tests/qemuxml2argvdata/hugepages-pages.xml b/tests/qemuxml2argvdata/hugepages-pages.xml
index f9270782d4..cba83e754c 100644
--- a/tests/qemuxml2argvdata/hugepages-pages.xml
+++ b/tests/qemuxml2argvdata/hugepages-pages.xml
@@ -8,6 +8,7 @@
       
       
     
+    
   
   4
   
@@ -21,7 +22,7 @@
   
     
       
-      
+      
       
       
     
diff --git a/tests/qemuxml2argvdata/hugepages-pages3.xml b/tests/qemuxml2argvdata/hugepages-pages3.xml
index 3d3b3f3cc3..147acc4c95 100644
--- a/tests/qemuxml2argvdata/hugepages-pages3.xml
+++ b/tests/qemuxml2argvdata/hugepages-pages3.xml
@@ -15,8 +15,8 @@
   
   
     
-      
-      
+      
+      
     
   
   
diff --git a/tests/qemuxml2argvdata/hugepages-pages7.xml b/tests/qemuxml2argvdata/hugepages-pages7.xml
index d75cf5afa3..28c72f85a7 100644
--- a/tests/qemuxml2argvdata/hugepages-pages7.xml
+++ b/tests/qemuxml2argvdata/hugepages-pages7.xml
@@ -43,7 +43,7 @@
     
       

     
-    
+    
       
         1-3
         1048576
@@ -54,7 +54,7 @@
       
       

     
-    
+    
       
         524287
         0
diff --git a/tests/qemuxml2xmloutdata/hugepages-pages.xml b/tests/qemuxml2xmloutdata/hugepages-pages.xml
index 498610a217..292454588e 100644
--- a/tests/qemuxml2xmloutdata/hugepages-pages.xml
+++ b/tests/qemuxml2xmloutdata/hugepages-pages.xml
@@ -8,6 +8,7 @@
       
       
     
+    
   
   4
   
@@ -21,7 +22,7 @@
   
     
       
-      
+      
       
       
     
diff --git a/tests/qemuxml2xmloutdata/hugepages-pages3.xml b/tests/qemuxml2xmloutdata/hugepages-pages3.xml
index be21c3eddd..90e6efa5ea 100644
--- a/tests/qemuxml2xmloutdata/hugepages-pages3.xml
+++ b/tests/qemuxml2xmloutdata/hugepages-pages3.xml
@@ -15,8 +15,8 @@
   
   
     
-      
-      
+      
+