Re: [Qemu-devel] [PATCH] hw/net: fix vmxnet3 live migration

[Dmitry Fleytman]

> On 8 Jul 2019, at 19:03, Dr. David Alan Gilbert <address@hidden> wrote:
> 
> * Marcel Apfelbaum (address@hidden) wrote:
>> 
>> 
>>> On 7/5/19 2:14 PM, Sukrit Bhatnagar wrote:
>>>> On Fri, 5 Jul 2019 at 16:29, Dmitry Fleytman <address@hidden> wrote:
>>>> 
>>>>> On 5 Jul 2019, at 4:07, Marcel Apfelbaum <address@hidden> wrote:
>>>>> 
>>>>> At some point vmxnet3 live migration stopped working and git-bisect
>>>>> didn't help finding a working version.
>>>>> The issue is the PCI configuration space is not being migrated
>>>>> successfully and MSIX remains masked at destination.
>>>>> 
>>>>> Remove the migration differentiation between PCI and PCIe since
>>>>> the logic resides now inside VMSTATE_PCI_DEVICE.
>>>>> Remove also the VMXNET3_COMPAT_FLAG_DISABLE_PCIE based differentiation
>>>>> since at 'realize' time is decided if the device is PCI or PCIe,
>>>>> then the above macro is enough.
>>>>> 
>>>>> Use the opportunity to move to the standard VMSTATE_MSIX
>>>>> instead of the deprecated SaveVMHandlers.
>>>>> 
>>>>> Signed-off-by: Marcel Apfelbaum <address@hidden>
>>>> 
>>>> Reviewed-by: Dmitry Fleytman <address@hidden>
>>>> 
>>> Tested-by: Sukrit Bhatnagar <address@hidden>
>> 
>> Thanks for the fast testing and review!
>> 
>> David, since the live migration was broken long before this patch,
>> I don't need  to add any compatibility code, right?
> 
> Right, although we should probably bump the version_id field, that way
> you'll get a nice clean error if you try and migrate from the old<->new.
> 
> (It's nice to get rid of the old msix oddity).
> 
>> If so, can you merge it using your migration tree?
> 
> I could do; or since it's entirely in vmxnet3 Dmitry can take it.

Dave, please take it to your migration tree.
Thanks, Dmitry.

> 
> Dave
> 
>> Thanks,
>> Marcel
>> 
>> 
>>>>> ---
>>>>> hw/net/vmxnet3.c | 52 ++----------------------------------------------
>>>>> 1 file changed, 2 insertions(+), 50 deletions(-)
>>>>> 
>>>>> diff --git a/hw/net/vmxnet3.c b/hw/net/vmxnet3.c
>>>>> index 10d01d0058..8b17548b02 100644
>>>>> --- a/hw/net/vmxnet3.c
>>>>> +++ b/hw/net/vmxnet3.c
>>>>> @@ -2141,21 +2141,6 @@ vmxnet3_cleanup_msi(VMXNET3State *s)
>>>>>     msi_uninit(d);
>>>>> }
>>>>> 
>>>>> -static void
>>>>> -vmxnet3_msix_save(QEMUFile *f, void *opaque)
>>>>> -{
>>>>> -    PCIDevice *d = PCI_DEVICE(opaque);
>>>>> -    msix_save(d, f);
>>>>> -}
>>>>> -
>>>>> -static int
>>>>> -vmxnet3_msix_load(QEMUFile *f, void *opaque, int version_id)
>>>>> -{
>>>>> -    PCIDevice *d = PCI_DEVICE(opaque);
>>>>> -    msix_load(d, f);
>>>>> -    return 0;
>>>>> -}
>>>>> -
>>>>> static const MemoryRegionOps b0_ops = {
>>>>>     .read = vmxnet3_io_bar0_read,
>>>>>     .write = vmxnet3_io_bar0_write,
>>>>> @@ -2176,11 +2161,6 @@ static const MemoryRegionOps b1_ops = {
>>>>>     },
>>>>> };
>>>>> 
>>>>> -static SaveVMHandlers savevm_vmxnet3_msix = {
>>>>> -    .save_state = vmxnet3_msix_save,
>>>>> -    .load_state = vmxnet3_msix_load,
>>>>> -};
>>>>> -
>>>>> static uint64_t vmxnet3_device_serial_num(VMXNET3State *s)
>>>>> {
>>>>>     uint64_t dsn_payload;
>>>>> @@ -2203,7 +2183,6 @@ static uint64_t 
>>>>> vmxnet3_device_serial_num(VMXNET3State *s)
>>>>> 
>>>>> static void vmxnet3_pci_realize(PCIDevice *pci_dev, Error **errp)
>>>>> {
>>>>> -    DeviceState *dev = DEVICE(pci_dev);
>>>>>     VMXNET3State *s = VMXNET3(pci_dev);
>>>>>     int ret;
>>>>> 
>>>>> @@ -2249,8 +2228,6 @@ static void vmxnet3_pci_realize(PCIDevice *pci_dev, 
>>>>> Error **errp)
>>>>>         pcie_dev_ser_num_init(pci_dev, VMXNET3_DSN_OFFSET,
>>>>>                               vmxnet3_device_serial_num(s));
>>>>>     }
>>>>> -
>>>>> -    register_savevm_live(dev, "vmxnet3-msix", -1, 1, 
>>>>> &savevm_vmxnet3_msix, s);
>>>>> }
>>>>> 
>>>>> static void vmxnet3_instance_init(Object *obj)
>>>>> @@ -2440,29 +2417,6 @@ static const VMStateDescription 
>>>>> vmstate_vmxnet3_int_state = {
>>>>>     }
>>>>> };
>>>>> 
>>>>> -static bool vmxnet3_vmstate_need_pcie_device(void *opaque)
>>>>> -{
>>>>> -    VMXNET3State *s = VMXNET3(opaque);
>>>>> -
>>>>> -    return !(s->compat_flags & VMXNET3_COMPAT_FLAG_DISABLE_PCIE);
>>>>> -}
>>>>> -
>>>>> -static bool vmxnet3_vmstate_test_pci_device(void *opaque, int version_id)
>>>>> -{
>>>>> -    return !vmxnet3_vmstate_need_pcie_device(opaque);
>>>>> -}
>>>>> -
>>>>> -static const VMStateDescription vmstate_vmxnet3_pcie_device = {
>>>>> -    .name = "vmxnet3/pcie",
>>>>> -    .version_id = 1,
>>>>> -    .minimum_version_id = 1,
>>>>> -    .needed = vmxnet3_vmstate_need_pcie_device,
>>>>> -    .fields = (VMStateField[]) {
>>>>> -        VMSTATE_PCI_DEVICE(parent_obj, VMXNET3State),
>>>>> -        VMSTATE_END_OF_LIST()
>>>>> -    }
>>>>> -};
>>>>> -
>>>>> static const VMStateDescription vmstate_vmxnet3 = {
>>>>>     .name = "vmxnet3",
>>>>>     .version_id = 1,
>>>>> @@ -2470,9 +2424,8 @@ static const VMStateDescription vmstate_vmxnet3 = {
>>>>>     .pre_save = vmxnet3_pre_save,
>>>>>     .post_load = vmxnet3_post_load,
>>>>>     .fields = (VMStateField[]) {
>>>>> -            VMSTATE_STRUCT_TEST(parent_obj, VMXNET3State,
>>>>> -                                vmxnet3_vmstate_test_pci_device, 0,
>>>>> -                                vmstate_pci_device, PCIDevice),
>>>>> +            VMSTATE_PCI_DEVICE(parent_obj, VMXNET3State),
>>>>> +            VMSTATE_MSIX(parent_obj, VMXNET3State),
>>>>>             VMSTATE_BOOL(rx_packets_compound, VMXNET3State),
>>>>>             VMSTATE_BOOL(rx_vlan_stripping, VMXNET3State),
>>>>>             VMSTATE_BOOL(lro_supported, VMXNET3State),
>>>>> @@ -2508,7 +2461,6 @@ static const VMStateDescription vmstate_vmxnet3 = {
>>>>>     },
>>>>>     .subsections = (const VMStateDescription*[]) {
>>>>>         &vmxstate_vmxnet3_mcast_list,
>>>>> -        &vmstate_vmxnet3_pcie_device,
>>>>>         NULL
>>>>>     }
>>>>> };
>>>>> --
>>>>> 2.17.1
>>>>> 
>> 
> --
> Dr. David Alan Gilbert / address@hidden / Manchester, UK