[Qemu-devel] [PATCH V1 0/2] Versioning ARM virt machine types

[Qemu-devel] [PATCH V1 0/2] Versioning ARM virt machine types

[Wei Huang]

We start to see more features been added to ARM virtual machine models.
For the purpose of backward compatibility (e.g. migration), it is time
to consider versioning machine types for ARM VMs. As a beginning step, this
patchset defines an abstract machine type for ARM VMs. The current
"virt" machine is re-written based on this new abstract type accordingly.
These patches have been verified by booting existing VMs.

RFC->V1:
 * Rename the machine type to "virt-2.6", matching the imminent QEMU version
 * Remove mc->is_default (Peter's comment)

Thanks,
-Wei

Wei Huang (2):
  arm: virt: Add an abstract ARM virt machine type
  arm: virt: Move machine class init code to the abstract machine type

 hw/arm/virt.c | 57 ++++++++++++++++++++++++++++++++++++++-------------------
 1 file changed, 38 insertions(+), 19 deletions(-)

-- 
1.8.3.1

[Qemu-devel] [PATCH V1 1/2] arm: virt: Add an abstract ARM virt machine type

[Wei Huang]

In preparation for future ARM virt machine types, this patch creates
an abstract type for all ARM machines. The current machine type in
QEMU (i.e. "virt") is renamed to "virt-2.6", whose naming scheme is
similar to other architectures. For the purpose of backward compatibility,
"virt" is converted to an alias, pointing to "virt-2.6". With this patch,
"qemu -M ?" lists the following virtual machine types along with others:

virt                 QEMU 2.6 ARM Virtual Machine (alias of virt-2.6)
virt-2.6             QEMU 2.6 ARM Virtual Machine

Signed-off-by: Wei Huang <wei@redhat.com>
---
 hw/arm/virt.c | 23 ++++++++++++++++++-----
 1 file changed, 18 insertions(+), 5 deletions(-)

diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 8c6c996..be9bbfb 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -1345,6 +1345,19 @@ static void virt_set_gic_version(Object *obj, const char *value, Error **errp)
     }
 }
 
+static void virt_machine_class_init(ObjectClass *oc, void *data)
+{
+}
+
+static const TypeInfo virt_machine_info = {
+    .name          = TYPE_VIRT_MACHINE,
+    .parent        = TYPE_MACHINE,
+    .abstract      = true,
+    .instance_size = sizeof(VirtMachineState),
+    .class_size    = sizeof(VirtMachineClass),
+    .class_init    = virt_machine_class_init,
+};
+
 static void virt_instance_init(Object *obj)
 {
     VirtMachineState *vms = VIRT_MACHINE(obj);
@@ -1382,7 +1395,8 @@ static void virt_class_init(ObjectClass *oc, void *data)
 {
     MachineClass *mc = MACHINE_CLASS(oc);
 
-    mc->desc = "ARM Virtual Machine",
+    mc->desc = "QEMU 2.6 ARM Virtual Machine";
+    mc->alias = "virt";
     mc->init = machvirt_init;
     /* Start max_cpus at the maximum QEMU supports. We'll further restrict
      * it later in machvirt_init, where we have more information about the
@@ -1396,16 +1410,15 @@ static void virt_class_init(ObjectClass *oc, void *data)
 }
 
 static const TypeInfo machvirt_info = {
-    .name = TYPE_VIRT_MACHINE,
-    .parent = TYPE_MACHINE,
-    .instance_size = sizeof(VirtMachineState),
+    .name = MACHINE_TYPE_NAME("virt-2.6"),
+    .parent = TYPE_VIRT_MACHINE,
     .instance_init = virt_instance_init,
-    .class_size = sizeof(VirtMachineClass),
     .class_init = virt_class_init,
 };
 
 static void machvirt_machine_init(void)
 {
+    type_register_static(&virt_machine_info);
     type_register_static(&machvirt_info);
 }
 
-- 
1.8.3.1

[Qemu-devel] [PATCH V1 2/2] arm: virt: Move machine class init code to the abstract machine type

[Wei Huang]

This patch moves the common class initialization code from
"virt-2.6" to the new abstract class. An empty property is added to
"virt-2.6" machine. In the meanwhile, related funtions are renamed
to "virt_2_6_*" for consistency.

Signed-off-by: Wei Huang <wei@redhat.com>
---
 hw/arm/virt.c | 34 ++++++++++++++++++++--------------
 1 file changed, 20 insertions(+), 14 deletions(-)

diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index be9bbfb..8c3ac0d 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -1347,6 +1347,18 @@ static void virt_set_gic_version(Object *obj, const char *value, Error **errp)
 
 static void virt_machine_class_init(ObjectClass *oc, void *data)
 {
+    MachineClass *mc = MACHINE_CLASS(oc);
+
+    mc->init = machvirt_init;
+    /* Start max_cpus at the maximum QEMU supports. We'll further restrict
+     * it later in machvirt_init, where we have more information about the
+     * configuration of the particular instance.
+     */
+    mc->max_cpus = MAX_CPUMASK_BITS;
+    mc->has_dynamic_sysbus = true;
+    mc->block_default_type = IF_VIRTIO;
+    mc->no_cdrom = 1;
+    mc->pci_allow_0_address = true;
 }
 
 static const TypeInfo virt_machine_info = {
@@ -1358,7 +1370,7 @@ static const TypeInfo virt_machine_info = {
     .class_init    = virt_machine_class_init,
 };
 
-static void virt_instance_init(Object *obj)
+static void virt_2_6_instance_init(Object *obj)
 {
     VirtMachineState *vms = VIRT_MACHINE(obj);
 
@@ -1391,29 +1403,23 @@ static void virt_instance_init(Object *obj)
                                     "Valid values are 2, 3 and host", NULL);
 }
 
-static void virt_class_init(ObjectClass *oc, void *data)
+static void virt_2_6_class_init(ObjectClass *oc, void *data)
 {
     MachineClass *mc = MACHINE_CLASS(oc);
+    static GlobalProperty compat_props[] = {
+        { /* end of list */ }
+    };
 
     mc->desc = "QEMU 2.6 ARM Virtual Machine";
     mc->alias = "virt";
-    mc->init = machvirt_init;
-    /* Start max_cpus at the maximum QEMU supports. We'll further restrict
-     * it later in machvirt_init, where we have more information about the
-     * configuration of the particular instance.
-     */
-    mc->max_cpus = MAX_CPUMASK_BITS;
-    mc->has_dynamic_sysbus = true;
-    mc->block_default_type = IF_VIRTIO;
-    mc->no_cdrom = 1;
-    mc->pci_allow_0_address = true;
+    mc->compat_props = compat_props;
 }
 
 static const TypeInfo machvirt_info = {
     .name = MACHINE_TYPE_NAME("virt-2.6"),
     .parent = TYPE_VIRT_MACHINE,
-    .instance_init = virt_instance_init,
-    .class_init = virt_class_init,
+    .instance_init = virt_2_6_instance_init,
+    .class_init = virt_2_6_class_init,
 };
 
 static void machvirt_machine_init(void)
-- 
1.8.3.1

Re: [Qemu-devel] [PATCH V1 0/2] Versioning ARM virt machine types

[Peter Maydell]

On 11 March 2016 at 17:36, Wei Huang <wei@redhat.com> wrote:
> We start to see more features been added to ARM virtual machine models.
> For the purpose of backward compatibility (e.g. migration), it is time
> to consider versioning machine types for ARM VMs. As a beginning step, this
> patchset defines an abstract machine type for ARM VMs. The current
> "virt" machine is re-written based on this new abstract type accordingly.
> These patches have been verified by booting existing VMs.
>
> RFC->V1:
>  * Rename the machine type to "virt-2.6", matching the imminent QEMU version
>  * Remove mc->is_default (Peter's comment)



Applied to target-arm.next, thanks.

-- PMM

Re: [Qemu-devel] [PATCH V1 0/2] Versioning ARM virt machine types

[Peter Maydell]

On 11 March 2016 at 17:36, Wei Huang <wei@redhat.com> wrote:
> We start to see more features been added to ARM virtual machine models.
> For the purpose of backward compatibility (e.g. migration), it is time
> to consider versioning machine types for ARM VMs. As a beginning step, this
> patchset defines an abstract machine type for ARM VMs. The current
> "virt" machine is re-written based on this new abstract type accordingly.
> These patches have been verified by booting existing VMs.
>
> RFC->V1:
>  * Rename the machine type to "virt-2.6", matching the imminent QEMU version
>  * Remove mc->is_default (Peter's comment)

So is there a plan to provide a virt-2.7 for the next release?

thanks
-- PMM

Re: [Qemu-devel] [PATCH V1 0/2] Versioning ARM virt machine types

[Andrew Jones]

On Tue, Jun 07, 2016 at 04:17:09PM +0100, Peter Maydell wrote:
> On 11 March 2016 at 17:36, Wei Huang <wei@redhat.com> wrote:
> > We start to see more features been added to ARM virtual machine models.
> > For the purpose of backward compatibility (e.g. migration), it is time
> > to consider versioning machine types for ARM VMs. As a beginning step, this
> > patchset defines an abstract machine type for ARM VMs. The current
> > "virt" machine is re-written based on this new abstract type accordingly.
> > These patches have been verified by booting existing VMs.
> >
> > RFC->V1:
> >  * Rename the machine type to "virt-2.6", matching the imminent QEMU version
> >  * Remove mc->is_default (Peter's comment)
> 
> So is there a plan to provide a virt-2.7 for the next release?

Yup. I was planning to send it as part of a small "hw/arm/virt: add
cpu-map" series I pretty much have ready, but didn't finish and send
yet because I got distracted working on the larger plan (among other
things). The motivation (larger plan) for cpu-map is full cpu-topology
configuration, but working on that has led to an smp parameter rework
RFC (hoping to send this week...) Wei or I can just send the virt-2.7
patch now though to get it done sooner than later.

Thanks,
drew

Re: [Qemu-devel] [PATCH V1 0/2] Versioning ARM virt machine types

[Wei Huang]

On 06/07/2016 11:51 PM, Andrew Jones wrote:
> On Tue, Jun 07, 2016 at 04:17:09PM +0100, Peter Maydell wrote:
>> On 11 March 2016 at 17:36, Wei Huang <wei@redhat.com> wrote:
>>> We start to see more features been added to ARM virtual machine models.
>>> For the purpose of backward compatibility (e.g. migration), it is time
>>> to consider versioning machine types for ARM VMs. As a beginning step, this
>>> patchset defines an abstract machine type for ARM VMs. The current
>>> "virt" machine is re-written based on this new abstract type accordingly.
>>> These patches have been verified by booting existing VMs.
>>>
>>> RFC->V1:
>>>  * Rename the machine type to "virt-2.6", matching the imminent QEMU version
>>>  * Remove mc->is_default (Peter's comment)
>>
>> So is there a plan to provide a virt-2.7 for the next release?
> 
> Yup. I was planning to send it as part of a small "hw/arm/virt: add
> cpu-map" series I pretty much have ready, but didn't finish and send
> yet because I got distracted working on the larger plan (among other
> things). The motivation (larger plan) for cpu-map is full cpu-topology
> configuration, but working on that has led to an smp parameter rework
> RFC (hoping to send this week...) Wei or I can just send the virt-2.7
> patch now though to get it done sooner than later.

It makes sense to go with Drew's patches, so he doesn't need to re-base
his existing current implementation.

> 
> Thanks,
> drew
>