Re: [Qemu-devel] [PATCH] ivshmem: add 64bit option

[Cam Macdonell <cam@cs.ualberta.ca>]

Thanks Gerd,

might need another rebase.  I have had some users request larger memory regions.

Quoting Gerd Hoffmann <kraxel@redhat.com>:
> This patch adds a "use64" property which will make the ivshmem driver
> register a 64bit memory bar when set, so you have something to play with
> when testing 64bit pci bits.  It also allows to have quite big shared
> memory regions, like this:
> 
> [root@fedora ~]# lspci -vs1:1
> 01:01.0 RAM memory: Red Hat, Inc Device 1110
>         Subsystem: Red Hat, Inc Device 1100
>         Physical Slot: 1-1
>         Flags: fast devsel
>         Memory at fd400000 (32-bit, non-prefetchable) [disabled] [size=256]
>         Memory at 8040000000 (64-bit, prefetchable) [size=1G]
> 
> [ v3: rebase & adapt to latest master ]
> [ v2: default to on as suggested by avi,
>       turn off for pc-$old using compat property ]
> 
> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Tested-by: Cam Macdonell <cam@cs.ualberta.ca>
> ---
>  hw/ivshmem.c |   13 ++++++++++---
>  hw/pc_piix.c |    4 ++++
>  2 files changed, 14 insertions(+), 3 deletions(-)
> 
> diff --git a/hw/ivshmem.c b/hw/ivshmem.c
> index 05559b6..8a776e2 100644
> --- a/hw/ivshmem.c
> +++ b/hw/ivshmem.c
> @@ -72,6 +72,8 @@ typedef struct IVShmemState {
>      MemoryRegion ivshmem;
>      MemoryRegion msix_bar;
>      uint64_t ivshmem_size; /* size of shared memory region */
> +    uint32_t ivshmem_attr;
> +    uint32_t ivshmem_64bit;
>      int shm_fd; /* shared memory file descriptor */
>  
>      Peer *peers;
> @@ -344,7 +346,7 @@ static void create_shared_memory_BAR(IVShmemState *s, int fd) {
>      memory_region_add_subregion(&s->bar, 0, &s->ivshmem);
>  
>      /* region for shared memory */
> -    pci_register_bar(&s->dev, 2, PCI_BASE_ADDRESS_SPACE_MEMORY, &s->bar);
> +    pci_register_bar(&s->dev, 2, s->ivshmem_attr, &s->bar);
>  }
>  
>  static void close_guest_eventfds(IVShmemState *s, int posn)
> @@ -693,6 +695,11 @@ static int pci_ivshmem_init(PCIDevice *dev)
>                       &s->ivshmem_mmio);
>  
>      memory_region_init(&s->bar, "ivshmem-bar2-container", s->ivshmem_size);
> +    s->ivshmem_attr = PCI_BASE_ADDRESS_SPACE_MEMORY |
> +        PCI_BASE_ADDRESS_MEM_PREFETCH;
> +    if (s->ivshmem_64bit) {
> +        s->ivshmem_attr |= PCI_BASE_ADDRESS_MEM_TYPE_64;
> +    }
>  
>      if ((s->server_chr != NULL) &&
>                          (strncmp(s->server_chr->filename, "unix:", 5) == 0)) {
> @@ -718,8 +725,7 @@ static int pci_ivshmem_init(PCIDevice *dev)
>          /* allocate/initialize space for interrupt handling */
>          s->peers = g_malloc0(s->nb_peers * sizeof(Peer));
>  
> -        pci_register_bar(&s->dev, 2,
> -                         PCI_BASE_ADDRESS_SPACE_MEMORY, &s->bar);
> +        pci_register_bar(&s->dev, 2, s->ivshmem_attr, &s->bar);
>  
>          s->eventfd_chr = g_malloc0(s->vectors * sizeof(CharDriverState *));
>  
> @@ -791,6 +797,7 @@ static Property ivshmem_properties[] = {
>      DEFINE_PROP_BIT("msi", IVShmemState, features, IVSHMEM_MSI, true),
>      DEFINE_PROP_STRING("shm", IVShmemState, shmobj),
>      DEFINE_PROP_STRING("role", IVShmemState, role),
> +    DEFINE_PROP_UINT32("use64", IVShmemState, ivshmem_64bit, 1),
>      DEFINE_PROP_END_OF_LIST(),
>  };
>  
> diff --git a/hw/pc_piix.c b/hw/pc_piix.c
> index 0c0096f..5101f5d 100644
> --- a/hw/pc_piix.c
> +++ b/hw/pc_piix.c
> @@ -375,6 +375,10 @@ static QEMUMachine pc_machine_v1_2 = {
>              .driver   = "qxl",\
>              .property = "vgamem_mb",\
>              .value    = stringify(8),\
> +        },{\
> +            .driver   = "ivshmem",\
> +            .property = "use64",\
> +            .value    = "0",\
>          }
>  
>  static QEMUMachine pc_machine_v1_1 = {
> -- 
> 1.7.1
> 
>