Re: [Qemu-devel] [PATCH v4 3/5] hw/pci: introduce bridge-only vendor-specific capability to provide some hints to firmware

[Marcel Apfelbaum <marcel@redhat.com>]

On 05/08/2017 23:27, Aleksandr Bezzubikov wrote:
> On PCI init PCI bridges may need some extra info about bus number,
> IO, memory and prefetchable memory to reserve. QEMU can provide this
> with a special vendor-specific PCI capability.
> 

Hi Aleksandr,

> Signed-off-by: Aleksandr Bezzubikov <zuban32s@gmail.com>
> ---
>   hw/pci/pci_bridge.c         | 29 +++++++++++++++++++++++++++++
>   include/hw/pci/pci_bridge.h | 21 +++++++++++++++++++++
>   2 files changed, 50 insertions(+)
> 
> diff --git a/hw/pci/pci_bridge.c b/hw/pci/pci_bridge.c
> index 720119b..889950d 100644
> --- a/hw/pci/pci_bridge.c
> +++ b/hw/pci/pci_bridge.c
> @@ -408,6 +408,35 @@ void pci_bridge_map_irq(PCIBridge *br, const char* bus_name,
>       br->bus_name = bus_name;
>   }
>   
> +
> +int pci_bridge_qemu_reserve_cap_init(PCIDevice *dev, int cap_offset,
> +                              uint32_t bus_reserve, uint64_t io_reserve,
> +                              uint64_t non_pref_mem_reserve,
> +                              uint64_t pref_mem_reserve,
> +                              Error **errp)
> +{
> +    size_t cap_len = sizeof(PCIBridgeQemuCap);
> +    PCIBridgeQemuCap cap = {
> +            .len = cap_len,
> +            .type = REDHAT_PCI_CAP_QEMU_RESERVE,

I would change the type to:
    REDHAT_PCI_CAP_RESOURCE_RESERVE

QEMU is less important here (I think) than "resource".

> +            .bus_res = bus_reserve,
> +            .io = io_reserve,
> +            .mem = non_pref_mem_reserve,
> +            .mem_pref = pref_mem_reserve
> +    };
> +
> +    int offset = pci_add_capability(dev, PCI_CAP_ID_VNDR,
> +                                    cap_offset, cap_len, errp);
> +    if (offset < 0) {
> +        return offset;
> +    }
> +
> +    memcpy(dev->config + offset + PCI_CAP_FLAGS,
> +            (char *)&cap + PCI_CAP_FLAGS,
> +            cap_len - PCI_CAP_FLAGS);
> +    return 0;
> +}
> +
>   static const TypeInfo pci_bridge_type_info = {
>       .name = TYPE_PCI_BRIDGE,
>       .parent = TYPE_PCI_DEVICE,
> diff --git a/include/hw/pci/pci_bridge.h b/include/hw/pci/pci_bridge.h
> index ff7cbaa..be565f7 100644
> --- a/include/hw/pci/pci_bridge.h
> +++ b/include/hw/pci/pci_bridge.h
> @@ -67,4 +67,25 @@ void pci_bridge_map_irq(PCIBridge *br, const char* bus_name,
>   #define  PCI_BRIDGE_CTL_DISCARD_STATUS	0x400	/* Discard timer status */
>   #define  PCI_BRIDGE_CTL_DISCARD_SERR	0x800	/* Discard timer SERR# enable */
>   
> +typedef struct PCIBridgeQemuCap {
> +    uint8_t id;     /* Standard PCI capability header field */
> +    uint8_t next;   /* Standard PCI capability header field */
> +    uint8_t len;    /* Standard PCI vendor-specific capability header field */
> +    uint8_t type;   /* Red Hat vendor-specific capability type.
> +                       Types are defined with REDHAT_PCI_CAP_ prefix */
> +
> +    uint32_t bus_res;   /* Minimum number of buses to reserve */
> +    uint64_t io;        /* IO space to reserve */
> +    uint64_t mem;       /* Non-prefetchable memory to reserve */
> +    uint64_t mem_pref;  /* Prefetchable memory to reserve */
> +} PCIBridgeQemuCap;
> +
> +#define REDHAT_PCI_CAP_QEMU_RESERVE     1
> +
> +int pci_bridge_qemu_reserve_cap_init(PCIDevice *dev, int cap_offset,
> +                              uint32_t bus_reserve, uint64_t io_reserve,
> +                              uint64_t non_pref_mem_reserve,
> +                              uint64_t pref_mem_reserve,
> +                              Error **errp);
> +
>   #endif /* QEMU_PCI_BRIDGE_H */
> 

With the name change, the layout looks good to me:

    Reviewed-by: Marcel Apfelbaum <marcel@redhat.com>

Thanks,
Marcel