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

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* 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>


Queued

> ---
>  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 / dgilbert@redhat.com / Manchester, UK