Re: [Qemu-devel] [PATCH 1/3] pcie: remove mmconfig memory leak and wrap mmconfig update with transaction

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

On Fri, Feb 13, 2015 at 03:57:09PM +0100, Paolo Bonzini wrote:
> This memory leak was introduced inadvertently by omitting object_unparent.
> A better fix is to use the new memory_region_set_size instead of destroying
> and recreating the MMIO region on the fly.
> 
> Also, ensure that unmapping and remapping the region is done atomically.
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Reviewed-by: Michael S. Tsirkin <mst@redhat.com>

> ---
>  hw/pci/pcie_host.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/pci/pcie_host.c b/hw/pci/pcie_host.c
> index dfb4a2b..d8afba8 100644
> --- a/hw/pci/pcie_host.c
> +++ b/hw/pci/pcie_host.c
> @@ -88,6 +88,8 @@ static void pcie_host_init(Object *obj)
>      PCIExpressHost *e = PCIE_HOST_BRIDGE(obj);
>  
>      e->base_addr = PCIE_BASE_ADDR_UNMAPPED;
> +    memory_region_init_io(&e->mmio, OBJECT(e), &pcie_mmcfg_ops, e, "pcie-mmcfg-mmio",
> +                          PCIE_MMCFG_SIZE_MAX);
>  }
>  
>  void pcie_host_mmcfg_unmap(PCIExpressHost *e)
> @@ -104,8 +106,7 @@ void pcie_host_mmcfg_init(PCIExpressHost *e, uint32_t size)
>      assert(size >= PCIE_MMCFG_SIZE_MIN);
>      assert(size <= PCIE_MMCFG_SIZE_MAX);
>      e->size = size;
> -    memory_region_init_io(&e->mmio, OBJECT(e), &pcie_mmcfg_ops, e,
> -                          "pcie-mmcfg", e->size);
> +    memory_region_set_size(&e->mmio, e->size);
>  }
>  
>  void pcie_host_mmcfg_map(PCIExpressHost *e, hwaddr addr,
> @@ -121,10 +122,12 @@ void pcie_host_mmcfg_update(PCIExpressHost *e,
>                              hwaddr addr,
>                              uint32_t size)
>  {
> +    memory_region_transaction_begin();
>      pcie_host_mmcfg_unmap(e);
>      if (enable) {
>          pcie_host_mmcfg_map(e, addr, size);
>      }
> +    memory_region_transaction_commit();
>  }
>  
>  static const TypeInfo pcie_host_type_info = {
> -- 
> 1.8.3.1
>