Re: [Qemu-devel] [PATCH] vhost: skip RAM device memory sections

[Michael S. Tsirkin]

On Sat, Apr 08, 2017 at 09:24:10AM +0800, ZhiPeng Lu wrote:
> A RAM device represents a mapping to a physical device, such as to a PCI
> * MMIO BAR of an vfio-pci assigned device.
> Vhost listens to this region,and increases the region's reference count
> while passthrough?for?network adapters (Physical Function, PF or Virtual 
> Function, VF).
> After detaching   network adapters with  vhost backend dirver or vhost user 
> dirver,
> it unregister vhost listen function  by memory_listener_unregister.

Shouldn't that drop all references? That might be a cleaner fix.

> After detaching the passthrough pf  or vf,
> the RAM device region's reference by  vhost listener increated can not be 
> released,
> due to vhost listen function does not exist.So let's just skip RAM device 
> memory.
> 
> Signed-off-by: ZhiPeng Lu <address@hidden>
> ---
>  hw/virtio/vhost.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
> index 613494d..c1ff98f 100644
> --- a/hw/virtio/vhost.c
> +++ b/hw/virtio/vhost.c
> @@ -611,7 +611,8 @@ static void vhost_set_memory(MemoryListener *listener,
>  static bool vhost_section(MemoryRegionSection *section)
>  {
>      return memory_region_is_ram(section->mr) &&
> -        !memory_region_is_rom(section->mr);
> +        !memory_region_is_rom(section->mr) &&
> +        !memory_region_is_skip_dump(section->mr);
>  }
>  
>  static void vhost_begin(MemoryListener *listener)
> -- 
> 1.8.3.1
>