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[PATCH 6/6] hw/ide/piix: Move registration of VMStateDescription to DeviceClass

Bernhard Beschow posted 6 patches 2 years, 8 months ago
Maintainers: John Snow <jsnow@redhat.com>, BALATON Zoltan <balaton@eik.bme.hu>, Huacai Chen <chenhuacai@kernel.org>, "Philippe Mathieu-Daudé" <philmd@linaro.org>, Jiaxun Yang <jiaxun.yang@flygoat.com>
There is a newer version of this series
[PATCH 6/6] hw/ide/piix: Move registration of VMStateDescription to DeviceClass
Posted by Bernhard Beschow 2 years, 8 months ago 
The modern, declarative way to set up VM state handling is to assign to
DeviceClass::vmsd attribute.

There shouldn't be any change in behavior since dc->vmsd causes
vmstate_register_with_alias_id() to be called on the instance during
the instance init phase. vmstate_register() was also called during the
instance init phase which forwards to vmstate_register_with_alias_id()
internally. Checking the migration schema before and after this patch confirms:

before:
> qemu-system-x86_64 -S
> qemu > migrate -d exec:cat>before.mig

after:
> qemu-system-x86_64 -S
> qemu > migrate -d exec:cat>after.mig

> analyze-migration.py -d desc -f before.mig > before.json
> analyze-migration.py -d desc -f after.mig > after.json
> diff before.json after.json
-> empty
---
 hw/ide/piix.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/hw/ide/piix.c b/hw/ide/piix.c
index 47e0b474c3..151f206046 100644
--- a/hw/ide/piix.c
+++ b/hw/ide/piix.c
@@ -28,7 +28,6 @@
  */
 
 #include "qemu/osdep.h"
-#include "migration/vmstate.h"
 #include "qapi/error.h"
 #include "hw/pci/pci.h"
 #include "hw/ide/piix.h"
@@ -159,8 +158,6 @@ static void pci_piix_ide_realize(PCIDevice *dev, Error **errp)
     bmdma_setup_bar(d);
     pci_register_bar(dev, 4, PCI_BASE_ADDRESS_SPACE_IO, &d->bmdma_bar);
 
-    vmstate_register(VMSTATE_IF(dev), 0, &vmstate_ide_pci, d);
-
     for (unsigned i = 0; i < 2; i++) {
         if (!pci_piix_init_bus(d, i, errp)) {
             return;
@@ -186,6 +183,7 @@ static void piix3_ide_class_init(ObjectClass *klass, void *data)
     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
 
     dc->reset = piix_ide_reset;
+    dc->vmsd = &vmstate_ide_pci;
     k->realize = pci_piix_ide_realize;
     k->exit = pci_piix_ide_exitfn;
     k->vendor_id = PCI_VENDOR_ID_INTEL;
@@ -208,6 +206,7 @@ static void piix4_ide_class_init(ObjectClass *klass, void *data)
     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
 
     dc->reset = piix_ide_reset;
+    dc->vmsd = &vmstate_ide_pci;
     k->realize = pci_piix_ide_realize;
     k->exit = pci_piix_ide_exitfn;
     k->vendor_id = PCI_VENDOR_ID_INTEL;
-- 
2.40.1
Re: [PATCH 6/6] hw/ide/piix: Move registration of VMStateDescription to DeviceClass
Posted by Mark Cave-Ayland 2 years, 8 months ago 
On 21/05/2023 12:15, Bernhard Beschow wrote:

> The modern, declarative way to set up VM state handling is to assign to
> DeviceClass::vmsd attribute.
> 
> There shouldn't be any change in behavior since dc->vmsd causes
> vmstate_register_with_alias_id() to be called on the instance during
> the instance init phase. vmstate_register() was also called during the
> instance init phase which forwards to vmstate_register_with_alias_id()
> internally. Checking the migration schema before and after this patch confirms:
> 
> before:
>> qemu-system-x86_64 -S
>> qemu > migrate -d exec:cat>before.mig
> 
> after:
>> qemu-system-x86_64 -S
>> qemu > migrate -d exec:cat>after.mig
> 
>> analyze-migration.py -d desc -f before.mig > before.json
>> analyze-migration.py -d desc -f after.mig > after.json
>> diff before.json after.json
> -> empty
> ---
>   hw/ide/piix.c | 5 ++---
>   1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/hw/ide/piix.c b/hw/ide/piix.c
> index 47e0b474c3..151f206046 100644
> --- a/hw/ide/piix.c
> +++ b/hw/ide/piix.c
> @@ -28,7 +28,6 @@
>    */
>   
>   #include "qemu/osdep.h"
> -#include "migration/vmstate.h"
>   #include "qapi/error.h"
>   #include "hw/pci/pci.h"
>   #include "hw/ide/piix.h"
> @@ -159,8 +158,6 @@ static void pci_piix_ide_realize(PCIDevice *dev, Error **errp)
>       bmdma_setup_bar(d);
>       pci_register_bar(dev, 4, PCI_BASE_ADDRESS_SPACE_IO, &d->bmdma_bar);
>   
> -    vmstate_register(VMSTATE_IF(dev), 0, &vmstate_ide_pci, d);
> -
>       for (unsigned i = 0; i < 2; i++) {
>           if (!pci_piix_init_bus(d, i, errp)) {
>               return;
> @@ -186,6 +183,7 @@ static void piix3_ide_class_init(ObjectClass *klass, void *data)
>       PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
>   
>       dc->reset = piix_ide_reset;
> +    dc->vmsd = &vmstate_ide_pci;
>       k->realize = pci_piix_ide_realize;
>       k->exit = pci_piix_ide_exitfn;
>       k->vendor_id = PCI_VENDOR_ID_INTEL;
> @@ -208,6 +206,7 @@ static void piix4_ide_class_init(ObjectClass *klass, void *data)
>       PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
>   
>       dc->reset = piix_ide_reset;
> +    dc->vmsd = &vmstate_ide_pci;
>       k->realize = pci_piix_ide_realize;
>       k->exit = pci_piix_ide_exitfn;
>       k->vendor_id = PCI_VENDOR_ID_INTEL;

Thanks for confirming that the migration still works!

Reviewed-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>


ATB,

Mark.
Re: [PATCH 6/6] hw/ide/piix: Move registration of VMStateDescription to DeviceClass
Posted by BALATON Zoltan 2 years, 8 months ago 
On Sun, 21 May 2023, Bernhard Beschow wrote:
> The modern, declarative way to set up VM state handling is to assign to
> DeviceClass::vmsd attribute.
>
> There shouldn't be any change in behavior since dc->vmsd causes
> vmstate_register_with_alias_id() to be called on the instance during
> the instance init phase. vmstate_register() was also called during the
> instance init phase which forwards to vmstate_register_with_alias_id()
> internally. Checking the migration schema before and after this patch confirms:
>
> before:
>> qemu-system-x86_64 -S
>> qemu > migrate -d exec:cat>before.mig
>
> after:
>> qemu-system-x86_64 -S
>> qemu > migrate -d exec:cat>after.mig
>
>> analyze-migration.py -d desc -f before.mig > before.json
>> analyze-migration.py -d desc -f after.mig > after.json
>> diff before.json after.json
> -> empty

Missing Signed-off-by line.

Regards,
BALATON Zoltah

> ---
> hw/ide/piix.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/hw/ide/piix.c b/hw/ide/piix.c
> index 47e0b474c3..151f206046 100644
> --- a/hw/ide/piix.c
> +++ b/hw/ide/piix.c
> @@ -28,7 +28,6 @@
>  */
>
> #include "qemu/osdep.h"
> -#include "migration/vmstate.h"
> #include "qapi/error.h"
> #include "hw/pci/pci.h"
> #include "hw/ide/piix.h"
> @@ -159,8 +158,6 @@ static void pci_piix_ide_realize(PCIDevice *dev, Error **errp)
>     bmdma_setup_bar(d);
>     pci_register_bar(dev, 4, PCI_BASE_ADDRESS_SPACE_IO, &d->bmdma_bar);
>
> -    vmstate_register(VMSTATE_IF(dev), 0, &vmstate_ide_pci, d);
> -
>     for (unsigned i = 0; i < 2; i++) {
>         if (!pci_piix_init_bus(d, i, errp)) {
>             return;
> @@ -186,6 +183,7 @@ static void piix3_ide_class_init(ObjectClass *klass, void *data)
>     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
>
>     dc->reset = piix_ide_reset;
> +    dc->vmsd = &vmstate_ide_pci;
>     k->realize = pci_piix_ide_realize;
>     k->exit = pci_piix_ide_exitfn;
>     k->vendor_id = PCI_VENDOR_ID_INTEL;
> @@ -208,6 +206,7 @@ static void piix4_ide_class_init(ObjectClass *klass, void *data)
>     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
>
>     dc->reset = piix_ide_reset;
> +    dc->vmsd = &vmstate_ide_pci;
>     k->realize = pci_piix_ide_realize;
>     k->exit = pci_piix_ide_exitfn;
>     k->vendor_id = PCI_VENDOR_ID_INTEL;
>

Patchew 2.1-devel-b67e4c2

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