[libvirt] [PATCH v5 15/15] qemu_driver: improve comparison/baseline error reporting

[Collin Walling]

Providing an erroneous CPU definition in the XML file provided to the
hypervisor-cpu-compare/baseline command will result in a verbose
internal error. Let's add some sanity checking before executing the QMP
commands to provide a cleaner message if something is wrong with the
CPU model or features.

Signed-off-by: Collin Walling <walling at linux.ibm.com>
---
 src/qemu/qemu_driver.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 62 insertions(+)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 153b2f2..6298c48 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -13703,6 +13703,55 @@ qemuConnectCompareCPU(virConnectPtr conn,
 }
 
 
+static int
+qemuConnectCheckCPUModel(qemuMonitorPtr mon,
+                         virCPUDefPtr cpu,
+                         bool reportError)
+{
+    qemuMonitorCPUModelInfoPtr modelInfo = NULL;
+    qemuMonitorCPUModelExpansionType type;
+    size_t i, j;
+    int ret = -1;
+
+    /* Collect CPU model name and features known by QEMU */
+    type = QEMU_MONITOR_CPU_MODEL_EXPANSION_FULL;
+    if (qemuMonitorGetCPUModelExpansion(mon, type, cpu,
+                                        true, false, &modelInfo) < 0)
+        goto cleanup;
+
+    /* Sanity check CPU model */
+    if (!modelInfo) {
+        if (reportError)
+            virReportError(VIR_ERR_CPU_INCOMPATIBLE,
+                           _("Unknown CPU model: %s"), cpu->model);
+        goto cleanup;
+    }
+
+    /* Sanity check CPU features */
+    for (i = 0; i < cpu->nfeatures; i++) {
+        const char *feat = cpu->features[i].name;
+
+        for (j = 0; j < modelInfo->nprops; j++) {
+            const char *prop = modelInfo->props[j].name;
+            if (STREQ(feat, prop))
+                break;
+        }
+
+        if (j == modelInfo->nprops) {
+            if (reportError)
+                virReportError(VIR_ERR_CPU_INCOMPATIBLE,
+                               _("Unknown CPU feature: %s"), feat);
+            goto cleanup;
+        }
+    }
+    ret = 0;
+
+ cleanup:
+    qemuMonitorCPUModelInfoFree(modelInfo);
+    return ret;
+}
+
+
 static virCPUCompareResult
 qemuConnectCPUModelComparison(virQEMUCapsPtr qemuCaps,
                               const char *libDir,
@@ -13723,6 +13772,13 @@ qemuConnectCPUModelComparison(virQEMUCapsPtr qemuCaps,
     if (qemuProcessQMPStart(proc) < 0)
         goto cleanup;
 
+    if (qemuConnectCheckCPUModel(proc->mon, cpu_a, failIncompatible) ||
+        qemuConnectCheckCPUModel(proc->mon, cpu_b, failIncompatible)) {
+        if (!failIncompatible)
+            ret = VIR_CPU_COMPARE_INCOMPATIBLE;
+        goto cleanup;
+    }
+
     if (qemuMonitorGetCPUModelComparison(proc->mon, cpu_a, cpu_b, &result) < 0)
         goto cleanup;
 
@@ -13913,6 +13969,9 @@ qemuConnectCPUModelBaseline(virQEMUCapsPtr qemuCaps,
     if (qemuProcessQMPStart(proc) < 0)
         goto cleanup;
 
+    if (qemuConnectCheckCPUModel(proc->mon, cpus[0], true))
+        goto cleanup;
+
     if (VIR_ALLOC(baseline) < 0)
         goto error;
 
@@ -13921,6 +13980,9 @@ qemuConnectCPUModelBaseline(virQEMUCapsPtr qemuCaps,
 
     for (i = 1; i < ncpus; i++) {
 
+        if (qemuConnectCheckCPUModel(proc->mon, cpus[i], true))
+            goto error;
+
         if (qemuMonitorGetCPUModelBaseline(proc->mon, baseline,
                                            cpus[i], &result) < 0)
             goto error;
-- 
2.7.4