Re: [Qemu-devel] [PATCH v3] ivshmem: Fix 64 bit memory bar configuration

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, Nov 17, 2016 at 08:31:03PM +0800, Zhuangyanying wrote:
> From: Zhuang Yanying <ann.zhuangyanying@huawei.com>
> 
>     Device ivshmem property use64=0 is designed to make the device
>     expose a 32 bit shared memory BAR instead of 64 bit one.  The
>     default is a 64 bit BAR, except pc-1.2 and older retain a 32 bit
>     BAR.  A 32 bit BAR can support only up to 1 GiB of shared memory.
> 
>     This worked as designed until commit 5400c02 accidentally flipped
>     its sense: since then, we misinterpret use64=0 as use64=1 and vice
>     versa.  Worse, the default got flipped as well.  Devices
>     ivshmem-plain and ivshmem-doorbell are not affected.
> 
>     Fix by restoring the test of IVShmemState member not_legacy_32bit
>     that got messed up in commit 5400c02.  Also update its
>     initialization for devices ivhsmem-plain and ivshmem-doorbell.
>     Without that, they'd regress to 32 bit BARs.
> 
>     Cc: qemu-stable@nongnu.org
>     Signed-off-by: Zhuang Yanying <ann.zhuangyanying@huawei.com>
>     Reviewed-by: Gonglei <arei.gonglei@huawei.com>
>     Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>

this is malformed, pls shift it left to start at beginning of the line.

> ---
>  hw/misc/ivshmem.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c
> index 230e51b..abeaf3d 100644
> --- a/hw/misc/ivshmem.c
> +++ b/hw/misc/ivshmem.c
> @@ -858,7 +858,7 @@ static void ivshmem_common_realize(PCIDevice *dev, Error **errp)
>      pci_register_bar(dev, 0, PCI_BASE_ADDRESS_SPACE_MEMORY,
>                       &s->ivshmem_mmio);
>  
> -    if (!s->not_legacy_32bit) {
> +    if (s->not_legacy_32bit) {
>          attr |= PCI_BASE_ADDRESS_MEM_TYPE_64;
>      }
>  
> @@ -1045,6 +1045,7 @@ static void ivshmem_plain_init(Object *obj)
>                               ivshmem_check_memdev_is_busy,
>                               OBJ_PROP_LINK_UNREF_ON_RELEASE,
>                               &error_abort);
> +    s->not_legacy_32bit = 1;
>  }
>  
>  static void ivshmem_plain_realize(PCIDevice *dev, Error **errp)
> @@ -1116,6 +1117,7 @@ static void ivshmem_doorbell_init(Object *obj)
>  
>      s->features |= (1 << IVSHMEM_MSI);
>      s->legacy_size = SIZE_MAX;  /* whatever the server sends */
> +    s->not_legacy_32bit = 1;
>  }
>  
>  static void ivshmem_doorbell_realize(PCIDevice *dev, Error **errp)
> -- 
> 1.8.3.1
>