Re: [Qemu-devel] [PATCH v2 4/5] vmxnet3: The vmxnet3 device is a PCIE endpoint

[Jason Wang <jasowang@redhat.com>]

On 12/02/2015 11:26 PM, Shmulik Ladkani wrote:
> Report the 'express endpoint' capability if on a PCIE bus.
>
> The 'x-disable-pcie' property is used for backwards compatability.
>
> Signed-off-by: Shmulik Ladkani <shmulik.ladkani@ravellosystems.com>
> ---
>  hw/net/vmxnet3.c    | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
>  include/hw/compat.h |  4 ++++
>  2 files changed, 58 insertions(+), 1 deletion(-)
>
> diff --git a/hw/net/vmxnet3.c b/hw/net/vmxnet3.c
> index d007314..1d0fb66 100644
> --- a/hw/net/vmxnet3.c
> +++ b/hw/net/vmxnet3.c
> @@ -40,7 +40,11 @@
>  #define VMXNET3_COMPAT_FLAG_OLD_MSI_OFFSETS_BIT 0
>  #define VMXNET3_COMPAT_FLAG_OLD_MSI_OFFSETS \
>      (1 << VMXNET3_COMPAT_FLAG_OLD_MSI_OFFSETS_BIT)
> +#define VMXNET3_COMPAT_FLAG_DISABLE_PCIE_BIT 1
> +#define VMXNET3_COMPAT_FLAG_DISABLE_PCIE \
> +    (1 << VMXNET3_COMPAT_FLAG_DISABLE_PCIE_BIT)
>  
> +#define VMXNET3_EXP_EP_OFFSET (0x48)
>  #define VMXNET3_MSI_OFFSET(s) \
>      ((s)->compat_flags & VMXNET3_COMPAT_FLAG_OLD_MSI_OFFSETS ? 0x50 : 0x84)
>  #define VMXNET3_MSIX_OFFSET(s) \
> @@ -121,6 +125,7 @@
>  
>  typedef struct VMXNET3Class {
>      PCIDeviceClass parent_class;
> +    DeviceRealize parent_dc_realize;
>  } VMXNET3Class;
>  
>  #define TYPE_VMXNET3 "vmxnet3"
> @@ -2257,6 +2262,10 @@ static void vmxnet3_pci_realize(PCIDevice *pci_dev, Error **errp)
>  
>      vmxnet3_net_init(s);
>  
> +    if (pci_is_express(pci_dev) && pci_bus_is_express(pci_dev->bus)) {

Looks like pci_bus_is_express() has been checked in
pcie_endpoint_cap_init().

> +        pcie_endpoint_cap_init(pci_dev, VMXNET3_EXP_EP_OFFSET);
> +    }
> +
>      register_savevm(dev, "vmxnet3-msix", -1, 1,
>                      vmxnet3_msix_save, vmxnet3_msix_load, s);
>  }
> @@ -2526,6 +2535,29 @@ static const VMStateInfo int_state_info = {
>      .put = vmxnet3_put_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_PCIE_DEVICE(parent_obj, VMXNET3State),
> +        VMSTATE_END_OF_LIST()
> +    }
> +};
> +
>  static const VMStateDescription vmstate_vmxnet3 = {
>      .name = "vmxnet3",
>      .version_id = 1,
> @@ -2533,7 +2565,9 @@ static const VMStateDescription vmstate_vmxnet3 = {
>      .pre_save = vmxnet3_pre_save,
>      .post_load = vmxnet3_post_load,
>      .fields = (VMStateField[]) {
> -            VMSTATE_PCI_DEVICE(parent_obj, VMXNET3State),
> +            VMSTATE_STRUCT_TEST(parent_obj, VMXNET3State,
> +                                vmxnet3_vmstate_test_pci_device, 0,
> +                                vmstate_pci_device, PCIDevice),
>              VMSTATE_BOOL(rx_packets_compound, VMXNET3State),
>              VMSTATE_BOOL(rx_vlan_stripping, VMXNET3State),
>              VMSTATE_BOOL(lro_supported, VMXNET3State),
> @@ -2568,6 +2602,7 @@ static const VMStateDescription vmstate_vmxnet3 = {
>      },
>      .subsections = (const VMStateDescription*[]) {
>          &vmxstate_vmxnet3_mcast_list,
> +        &vmstate_vmxnet3_pcie_device,
>          NULL
>      }
>  };
> @@ -2576,13 +2611,29 @@ static Property vmxnet3_properties[] = {
>      DEFINE_NIC_PROPERTIES(VMXNET3State, conf),	
>      DEFINE_PROP_BIT("x-old-msi-offsets", VMXNET3State, compat_flags,
>                      VMXNET3_COMPAT_FLAG_OLD_MSI_OFFSETS_BIT, false),
> +    DEFINE_PROP_BIT("x-disable-pcie", VMXNET3State, compat_flags,
> +                    VMXNET3_COMPAT_FLAG_DISABLE_PCIE_BIT, false),
>      DEFINE_PROP_END_OF_LIST(),
>  };
>  
> +static void vmxnet3_realize(DeviceState *qdev, Error **errp)
> +{
> +    VMXNET3Class *vc = VMXNET3_DEVICE_GET_CLASS(qdev);
> +    PCIDevice *pci_dev = PCI_DEVICE(qdev);
> +    VMXNET3State *s = VMXNET3(qdev);
> +
> +    if (!(s->compat_flags & VMXNET3_COMPAT_FLAG_DISABLE_PCIE)) {
> +        pci_dev->cap_present |= QEMU_PCI_CAP_EXPRESS;
> +    }
> +
> +    vc->parent_dc_realize(qdev, errp);
> +}

It's not clear that how the class helps here. Why not simply do
everthing in vmxnet3_pci_realize()?

> +
>  static void vmxnet3_class_init(ObjectClass *class, void *data)
>  {
>      DeviceClass *dc = DEVICE_CLASS(class);
>      PCIDeviceClass *c = PCI_DEVICE_CLASS(class);
> +    VMXNET3Class *vc = VMXNET3_DEVICE_CLASS(class);
>  
>      c->realize = vmxnet3_pci_realize;
>      c->exit = vmxnet3_pci_uninit;
> @@ -2592,6 +2643,8 @@ static void vmxnet3_class_init(ObjectClass *class, void *data)
>      c->class_id = PCI_CLASS_NETWORK_ETHERNET;
>      c->subsystem_vendor_id = PCI_VENDOR_ID_VMWARE;
>      c->subsystem_id = PCI_DEVICE_ID_VMWARE_VMXNET3;
> +    vc->parent_dc_realize = dc->realize;
> +    dc->realize = vmxnet3_realize;
>      dc->desc = "VMWare Paravirtualized Ethernet v3";
>      dc->reset = vmxnet3_qdev_reset;
>      dc->vmsd = &vmstate_vmxnet3;
> diff --git a/include/hw/compat.h b/include/hw/compat.h
> index 01e326d..642b082 100644
> --- a/include/hw/compat.h
> +++ b/include/hw/compat.h
> @@ -22,6 +22,10 @@
>              .driver   = "vmxnet3",\
>              .property = "x-old-msi-offsets",\
>              .value    = "on",\
> +        },{\
> +            .driver   = "vmxnet3",\
> +            .property = "x-disable-pcie",\
> +            .value    = "on",\
>          },

To have a better bisection behavior, we'd better enable and compat this
in next patch.

>  
>  #define HW_COMPAT_2_3 \