[libvirt] [PATCH RFC 3/7] libxl: implement virDomainInterfaceStats

[Joao Martins]

Introduce support for domainInterfaceStats API call for querying
network interface statistics. Consequently it also enables the
use of `virsh domifstat <dom> <interface name>` command.

For getting statistics we resort to virNetInterfaceStats and let
libvirt handle the platform specific nits. Note that the latter
is not yet supported in FreeBSD.

Signed-off-by: Joao Martins <joao.m.martins at oracle.com>
---
 src/libxl/libxl_driver.c | 53 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)

diff --git a/src/libxl/libxl_driver.c b/src/libxl/libxl_driver.c
index 43e9e47..dc83083 100644
--- a/src/libxl/libxl_driver.c
+++ b/src/libxl/libxl_driver.c
@@ -58,6 +58,7 @@
 #include "virhostdev.h"
 #include "network/bridge_driver.h"
 #include "locking/domain_lock.h"
+#include "virstats.h"
 
 #define VIR_FROM_THIS VIR_FROM_LIBXL
 
@@ -4640,6 +4641,57 @@ libxlDomainIsUpdated(virDomainPtr dom)
 }
 
 static int
+libxlDomainInterfaceStats(virDomainPtr dom,
+                          const char *path,
+                          virDomainInterfaceStatsPtr stats)
+{
+    libxlDriverPrivatePtr driver = dom->conn->privateData;
+    virDomainObjPtr vm;
+    int ret = -1;
+    int domid, devid;
+
+    if (!(vm = libxlDomObjFromDomain(dom)))
+        goto cleanup;
+
+    if (virDomainInterfaceStatsEnsureACL(dom->conn, vm->def) < 0)
+        goto cleanup;
+
+    if (libxlDomainObjBeginJob(driver, vm, LIBXL_JOB_QUERY) < 0)
+        goto cleanup;
+
+    if (!virDomainObjIsActive(vm)) {
+        virReportError(VIR_ERR_OPERATION_INVALID,
+                       "%s", _("domain is not running"));
+        goto endjob;
+    }
+
+    if (sscanf(path, "vif%d.%d", &domid, &devid) != 2) {
+            virReportError(VIR_ERR_INVALID_ARG, "%s",
+                           _("invalid path, unknown device"));
+            goto endjob;
+    }
+
+    if (domid != vm->def->id) {
+            virReportError(VIR_ERR_INVALID_ARG, "%s",
+                           _("invalid path, domid doesn't match"));
+            goto endjob;
+    }
+
+    ret = virNetInterfaceStats(path, stats);
+
+ endjob:
+    if (!libxlDomainObjEndJob(driver, vm)) {
+        virObjectUnlock(vm);
+        vm = NULL;
+    }
+
+ cleanup:
+    if (vm)
+        virObjectUnlock(vm);
+    return ret;
+}
+
+static int
 libxlDomainGetTotalCPUStats(libxlDriverPrivatePtr driver,
                             virDomainObjPtr vm,
                             virTypedParameterPtr params,
@@ -5407,6 +5459,7 @@ static virHypervisorDriver libxlHypervisorDriver = {
 #endif
     .nodeGetFreeMemory = libxlNodeGetFreeMemory, /* 0.9.0 */
     .nodeGetCellsFreeMemory = libxlNodeGetCellsFreeMemory, /* 1.1.1 */
+    .domainInterfaceStats = libxlDomainInterfaceStats, /* 1.2.20 */
     .domainMemoryStats = libxlDomainMemoryStats, /* 1.2.20 */
     .domainGetCPUStats = libxlDomainGetCPUStats, /* 1.2.20 */
     .connectDomainEventRegister = libxlConnectDomainEventRegister, /* 0.9.0 */
-- 
2.1.4