[libvirt] [PATCH 2/2] virConnectCompareCPU: Introduce FAIL_INCOMPATIBLE flag

[Jiri Denemark]

The new VIR_CONNECT_COMPARE_CPU_FAIL_INCOMPATIBLE flag for
virConnectCompareCPU can be used to get an error
(VIR_ERR_CPU_INCOMPATIBLE) describing the incompatibility instead of the
usual VIR_CPU_COMPARE_INCOMPATIBLE return code.

Signed-off-by: Jiri Denemark <jdenemar at redhat.com>
---
 include/libvirt/libvirt.h.in |  5 +++++
 src/bhyve/bhyve_driver.c     | 17 +++++++++++++----
 src/libvirt.c                |  9 +++++++--
 src/qemu/qemu_driver.c       | 17 +++++++++++++----
 tools/virsh-domain.c         | 11 +++++++++--
 5 files changed, 47 insertions(+), 12 deletions(-)

diff --git a/include/libvirt/libvirt.h.in b/include/libvirt/libvirt.h.in
index 3f7a201..594521e 100644
--- a/include/libvirt/libvirt.h.in
+++ b/include/libvirt/libvirt.h.in
@@ -4122,6 +4122,11 @@ typedef enum {
 #endif
 } virCPUCompareResult;
 
+typedef enum {
+    VIR_CONNECT_COMPARE_CPU_FAIL_INCOMPATIBLE = (1 << 0), /* treat incompatible
+                                                             CPUs as failure */
+} virConnectCompareCPUFlags;
+
 int virConnectCompareCPU(virConnectPtr conn,
                          const char *xmlDesc,
                          unsigned int flags);
diff --git a/src/bhyve/bhyve_driver.c b/src/bhyve/bhyve_driver.c
index 9bece84..d784ed1 100644
--- a/src/bhyve/bhyve_driver.c
+++ b/src/bhyve/bhyve_driver.c
@@ -1318,21 +1318,30 @@ bhyveConnectCompareCPU(virConnectPtr conn,
     bhyveConnPtr driver = conn->privateData;
     int ret = VIR_CPU_COMPARE_ERROR;
     virCapsPtr caps = NULL;
+    bool failIncompatible;
 
-    virCheckFlags(0, VIR_CPU_COMPARE_ERROR);
+    virCheckFlags(VIR_CONNECT_COMPARE_CPU_FAIL_INCOMPATIBLE,
+                  VIR_CPU_COMPARE_ERROR);
 
     if (virConnectCompareCPUEnsureACL(conn) < 0)
         goto cleanup;
 
+    failIncomaptible = !!(flags & VIR_CONNECT_COMPARE_CPU_FAIL_INCOMPATIBLE);
+
     if (!(caps = bhyveDriverGetCapabilities(driver)))
         goto cleanup;
 
     if (!caps->host.cpu ||
         !caps->host.cpu->model) {
-        VIR_WARN("cannot get host CPU capabilities");
-        ret = VIR_CPU_COMPARE_INCOMPATIBLE;
+        if (failIncomaptible) {
+            virReportError(VIR_ERR_CPU_INCOMPATIBLE, "%s",
+                           _("cannot get host CPU capabilities"));
+        } else {
+            VIR_WARN("cannot get host CPU capabilities");
+            ret = VIR_CPU_COMPARE_INCOMPATIBLE;
+        }
     } else {
-        ret = cpuCompareXML(caps->host.cpu, xmlDesc, false);
+        ret = cpuCompareXML(caps->host.cpu, xmlDesc, failIncomaptible);
     }
 
  cleanup:
diff --git a/src/libvirt.c b/src/libvirt.c
index a0cdfa2..48ce225 100644
--- a/src/libvirt.c
+++ b/src/libvirt.c
@@ -17245,11 +17245,16 @@ virConnectIsSecure(virConnectPtr conn)
  * virConnectCompareCPU:
  * @conn: virConnect connection
  * @xmlDesc: XML describing the CPU to compare with host CPU
- * @flags: extra flags; not used yet, so callers should always pass 0
+ * @flags: bitwise-OR of virConnectCompareCPUFlags
  *
  * Compares the given CPU description with the host CPU
  *
- * Returns comparison result according to enum virCPUCompareResult
+ * Returns comparison result according to enum virCPUCompareResult. If
+ * VIR_CONNECT_COMPARE_CPU_FAIL_INCOMPATIBLE is used and @xmlDesc CPU is
+ * incompatible with host CPU, this function will return VIR_CPU_COMPARE_ERROR
+ * (instead of VIR_CPU_COMPARE_INCOMPATIBLE) and the error will use
+ * VIR_ERR_CPU_INCOMPATIBLE code the error message will provide more details
+ * about the incompatibility.
  */
 int
 virConnectCompareCPU(virConnectPtr conn,
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 3c23fc7..d8cecff 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -11514,21 +11514,30 @@ qemuConnectCompareCPU(virConnectPtr conn,
     virQEMUDriverPtr driver = conn->privateData;
     int ret = VIR_CPU_COMPARE_ERROR;
     virCapsPtr caps = NULL;
+    bool failIncomaptible;
 
-    virCheckFlags(0, VIR_CPU_COMPARE_ERROR);
+    virCheckFlags(VIR_CONNECT_COMPARE_CPU_FAIL_INCOMPATIBLE,
+                  VIR_CPU_COMPARE_ERROR);
 
     if (virConnectCompareCPUEnsureACL(conn) < 0)
         goto cleanup;
 
+    failIncomaptible = !!(flags & VIR_CONNECT_COMPARE_CPU_FAIL_INCOMPATIBLE);
+
     if (!(caps = virQEMUDriverGetCapabilities(driver, false)))
         goto cleanup;
 
     if (!caps->host.cpu ||
         !caps->host.cpu->model) {
-        VIR_WARN("cannot get host CPU capabilities");
-        ret = VIR_CPU_COMPARE_INCOMPATIBLE;
+        if (failIncomaptible) {
+            virReportError(VIR_ERR_CPU_INCOMPATIBLE, "%s",
+                           _("cannot get host CPU capabilities"));
+        } else {
+            VIR_WARN("cannot get host CPU capabilities");
+            ret = VIR_CPU_COMPARE_INCOMPATIBLE;
+        }
     } else {
-        ret = cpuCompareXML(caps->host.cpu, xmlDesc, false);
+        ret = cpuCompareXML(caps->host.cpu, xmlDesc, failIncomaptible);
     }
 
  cleanup:
diff --git a/tools/virsh-domain.c b/tools/virsh-domain.c
index 0ae1538..f55dae4 100644
--- a/tools/virsh-domain.c
+++ b/tools/virsh-domain.c
@@ -6214,6 +6214,10 @@ static const vshCmdOptDef opts_cpu_compare[] = {
      .flags = VSH_OFLAG_REQ,
      .help = N_("file containing an XML CPU description")
     },
+    {.name = "error",
+     .type = VSH_OT_BOOL,
+     .help = N_("report error if CPUs are incompatible")
+    },
     {.name = NULL}
 };
 
@@ -6225,11 +6229,14 @@ cmdCPUCompare(vshControl *ctl, const vshCmd *cmd)
     char *buffer;
     int result;
     char *snippet = NULL;
-
+    unsigned int flags = 0;
     xmlDocPtr xml = NULL;
     xmlXPathContextPtr ctxt = NULL;
     xmlNodePtr node;
 
+    if (vshCommandOptBool(cmd, "error"))
+        flags |= VIR_CONNECT_COMPARE_CPU_FAIL_INCOMPATIBLE;
+
     if (vshCommandOptStringReq(ctl, cmd, "file", &from) < 0)
         return false;
 
@@ -6253,7 +6260,7 @@ cmdCPUCompare(vshControl *ctl, const vshCmd *cmd)
         goto cleanup;
     }
 
-    result = virConnectCompareCPU(ctl->conn, snippet, 0);
+    result = virConnectCompareCPU(ctl->conn, snippet, flags);
 
     switch (result) {
     case VIR_CPU_COMPARE_INCOMPATIBLE:
-- 
2.0.0