qmp: add QMP interface "query-cpu-model-expansion"

Let's provide a standardized interface to expand CPU models. This interface
can be used by tooling to get details about a specific CPU model in a
certain configuration, e.g. about the "host" model.

To take care of all architectures, two detail levels for an expansion
are introduced. Certain architectures might not support all detail levels.
While "full" will expand and indicate all relevant properties/features
of a CPU model, "static" expands to a static base CPU model, that will
never change between QEMU versions and therefore have the same features
when used under different compatibility machines.

Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Message-Id: <20160905085244.99980-26-dahi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>

diff --git a/include/sysemu/arch_init.h b/include/sysemu/arch_init.h
index d690dfabdfb548fbed9ab2e708610b5d6d8de650..37b2e8675ed780271756f451bcbd0257b91c409c 100644 (file)
--- a/include/sysemu/arch_init.h
+++ b/include/sysemu/arch_init.h
@@ -35,5 +35,8 @@ int kvm_available(void);
 int xen_available(void);
 
 CpuDefinitionInfoList *arch_query_cpu_definitions(Error **errp);
+CpuModelExpansionInfo *arch_query_cpu_model_expansion(CpuModelExpansionType type,
+                                                      CpuModelInfo *mode,
+                                                      Error **errp);
 
 #endif

diff --git a/qapi-schema.json b/qapi-schema.json
index 1c3533caacc36418d8c6b0e892cff0b588f958d1..1c2daad08737ca903ab8fb56b84977fa5d26d7cc 100644 (file)
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -3066,6 +3066,98 @@
 ##
 { 'command': 'query-cpu-definitions', 'returns': ['CpuDefinitionInfo'] }
 
+##
+# @CpuModelInfo:
+#
+# Virtual CPU model.
+#
+# A CPU model consists of the name of a CPU definition, to which
+# delta changes are applied (e.g. features added/removed). Most magic values
+# that an architecture might require should be hidden behind the name.
+# However, if required, architectures can expose relevant properties.
+#
+# @name: the name of the CPU definition the model is based on
+# @props: #optional a dictionary of QOM properties to be applied
+#
+# Since: 2.8.0
+##
+{ 'struct': 'CpuModelInfo',
+  'data': { 'name': 'str',
+            '*props': 'any' } }
+
+##
+# @CpuModelExpansionType
+#
+# An enumeration of CPU model expansion types.
+#
+# @static: Expand to a static CPU model, a combination of a static base
+#          model name and property delta changes. As the static base model will
+#          never change, the expanded CPU model will be the same, independant of
+#          independent of QEMU version, machine type, machine options, and
+#          accelerator options. Therefore, the resulting model can be used by
+#          tooling without having to specify a compatibility machine - e.g. when
+#          displaying the "host" model. static CPU models are migration-safe.
+#
+# @full: Expand all properties. The produced model is not guaranteed to be
+#        migration-safe, but allows tooling to get an insight and work with
+#        model details.
+#
+# Since: 2.8.0
+##
+{ 'enum': 'CpuModelExpansionType',
+  'data': [ 'static', 'full' ] }
+
+
+##
+# @CpuModelExpansionInfo
+#
+# The result of a cpu model expansion.
+#
+# @model: the expanded CpuModelInfo.
+#
+# Since: 2.8.0
+##
+{ 'struct': 'CpuModelExpansionInfo',
+  'data': { 'model': 'CpuModelInfo' } }
+
+
+##
+# @query-cpu-model-expansion:
+#
+# Expands a given CPU model (or a combination of CPU model + additional options)
+# to different granularities, allowing tooling to get an understanding what a
+# specific CPU model looks like in QEMU under a certain configuration.
+#
+# This interface can be used to query the "host" CPU model.
+#
+# The data returned by this command may be affected by:
+#
+# * QEMU version: CPU models may look different depending on the QEMU version.
+#   (Except for CPU models reported as "static" in query-cpu-definitions.)
+# * machine-type: CPU model  may look different depending on the machine-type.
+#   (Except for CPU models reported as "static" in query-cpu-definitions.)
+# * machine options (including accelerator): in some architectures, CPU models
+#   may look different depending on machine and accelerator options. (Except for
+#   CPU models reported as "static" in query-cpu-definitions.)
+# * "-cpu" arguments and global properties: arguments to the -cpu option and
+#   global properties may affect expansion of CPU models. Using
+#   query-cpu-model-expansion while using these is not advised.
+#
+# Some architectures may not support all expansion types.
+#
+# Returns: a CpuModelExpansionInfo. Returns an error if expanding CPU models is
+#          not supported, if the model cannot be expanded, if the model contains
+#          an unknown CPU definition name, unknown properties or properties
+#          with a wrong type. Also returns an error if an expansion type is
+#          not supported.
+#
+# Since: 2.8.0
+##
+{ 'command': 'query-cpu-model-expansion',
+  'data': { 'type': 'CpuModelExpansionType',
+            'model': 'CpuModelInfo' },
+  'returns': 'CpuModelExpansionInfo' }
+
 # @AddfdInfo:
 #
 # Information about a file descriptor that was added to an fd set.

diff --git a/qmp-commands.hx b/qmp-commands.hx
index 6866264e64fcb476406198fc8ccb0b67c9dd5556..26b91e41d2153b3148cfd1364f01a805ba1e584a 100644 (file)
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -3941,6 +3941,12 @@ EQMP
         .mhandler.cmd_new = qmp_marshal_query_cpu_definitions,
     },
 
+    {
+        .name       = "query-cpu-model-expansion",
+        .args_type  = "type:s,model:q",
+        .mhandler.cmd_new = qmp_marshal_query_cpu_model_expansion,
+    },
+
     {
         .name       = "query-target",
         .args_type  = "",

diff --git a/qmp.c b/qmp.c
index b6d531ebe2d722fdf50dd994bbe4eb6c62adc2fb..29fbfb811c4427b9ad773b6e73f376548a709dd0 100644 (file)
--- a/qmp.c
+++ b/qmp.c
@@ -607,6 +607,13 @@ CpuDefinitionInfoList *qmp_query_cpu_definitions(Error **errp)
     return arch_query_cpu_definitions(errp);
 }
 
+CpuModelExpansionInfo *qmp_query_cpu_model_expansion(CpuModelExpansionType type,
+                                                     CpuModelInfo *model,
+                                                     Error **errp)
+{
+    return arch_query_cpu_model_expansion(type, model, errp);
+}
+
 void qmp_add_client(const char *protocol, const char *fdname,
                     bool has_skipauth, bool skipauth, bool has_tls, bool tls,
                     Error **errp)

diff --git a/stubs/Makefile.objs b/stubs/Makefile.objs
index 55edd15d718e2264bcc0b2c0fd99acfffc101466..4929842d0b760ec5829694d393cc79b61bc4a652 100644 (file)
--- a/stubs/Makefile.objs
+++ b/stubs/Makefile.objs
@@ -1,4 +1,5 @@
 stub-obj-y += arch-query-cpu-def.o
+stub-obj-y += arch-query-cpu-model-expansion.o
 stub-obj-y += bdrv-next-monitor-owned.o
 stub-obj-y += blk-commit-all.o
 stub-obj-y += blockdev-close-all-bdrv-states.o

diff --git a/stubs/arch-query-cpu-model-expansion.c b/stubs/arch-query-cpu-model-expansion.c
new file mode 100644 (file)
index 0000000..ae7cf55
--- /dev/null
+++ b/stubs/arch-query-cpu-model-expansion.c
@@ -0,0 +1,12 @@
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+#include "sysemu/arch_init.h"
+#include "qapi/qmp/qerror.h"
+
+CpuModelExpansionInfo *arch_query_cpu_model_expansion(CpuModelExpansionType type,
+                                                      CpuModelInfo *mode,
+                                                      Error **errp)
+{
+    error_setg(errp, QERR_UNSUPPORTED);
+    return NULL;
+}