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

[Marcel Apfelbaum <marcel.apfelbaum@gmail.com>]

On 7/5/19 2:14 PM, Sukrit Bhatnagar wrote:
> On Fri, 5 Jul 2019 at 16:29, Dmitry Fleytman <dmitry.fleytman@gmail.com> wrote:
>>
>>> On 5 Jul 2019, at 4:07, Marcel Apfelbaum <marcel.apfelbaum@gmail.com> 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 <marcel.apfelbaum@gmail.com>
>>
>> Reviewed-by: Dmitry Fleytman <dmitry.fleytman@gmail.com>
>>
> Tested-by: Sukrit Bhatnagar <skrtbhtngr@gmail.com>

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?

If so, can you merge it using your migration tree?

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
>>>