[v6] vfio: Adopt iommufd

[PATCH v6 03/21] vfio/common: return early if space isn't empty

Posted by Zhenzhong Duan 1 year ago

This is a trivial optimization. If there is active container in space,
vfio_reset_handler will never be unregistered. So revert the check of
space->containers and return early.

Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
---
 hw/vfio/common.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 572ae7c934..934f4f5446 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -1462,10 +1462,13 @@ VFIOAddressSpace *vfio_get_address_space(AddressSpace *as)
 
 void vfio_put_address_space(VFIOAddressSpace *space)
 {
-    if (QLIST_EMPTY(&space->containers)) {
-        QLIST_REMOVE(space, list);
-        g_free(space);
+    if (!QLIST_EMPTY(&space->containers)) {
+        return;
     }
+
+    QLIST_REMOVE(space, list);
+    g_free(space);
+
     if (QLIST_EMPTY(&vfio_address_spaces)) {
         qemu_unregister_reset(vfio_reset_handler, NULL);
     }
-- 
2.34.1

Re: [PATCH v6 03/21] vfio/common: return early if space isn't empty

Posted by Eric Auger 1 year ago


On 11/14/23 11:09, Zhenzhong Duan wrote:
> This is a trivial optimization. If there is active container in space,
> vfio_reset_handler will never be unregistered. So revert the check of
> space->containers and return early.
>
> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>

Thanks

Eric
> ---
>  hw/vfio/common.c | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
> index 572ae7c934..934f4f5446 100644
> --- a/hw/vfio/common.c
> +++ b/hw/vfio/common.c
> @@ -1462,10 +1462,13 @@ VFIOAddressSpace *vfio_get_address_space(AddressSpace *as)
>  
>  void vfio_put_address_space(VFIOAddressSpace *space)
>  {
> -    if (QLIST_EMPTY(&space->containers)) {
> -        QLIST_REMOVE(space, list);
> -        g_free(space);
> +    if (!QLIST_EMPTY(&space->containers)) {
> +        return;
>      }
> +
> +    QLIST_REMOVE(space, list);
> +    g_free(space);
> +
>      if (QLIST_EMPTY(&vfio_address_spaces)) {
>          qemu_unregister_reset(vfio_reset_handler, NULL);
>      }

Re: [PATCH v6 03/21] vfio/common: return early if space isn't empty

Posted by Cédric Le Goater 1 year ago

On 11/14/23 11:09, Zhenzhong Duan wrote:
> This is a trivial optimization. If there is active container in space,
> vfio_reset_handler will never be unregistered. So revert the check of
> space->containers and return early.
> 
> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>


Reviewed-by: Cédric Le Goater <clg@redhat.com>

Thanks,

C.


> ---
>   hw/vfio/common.c | 9 ++++++---
>   1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
> index 572ae7c934..934f4f5446 100644
> --- a/hw/vfio/common.c
> +++ b/hw/vfio/common.c
> @@ -1462,10 +1462,13 @@ VFIOAddressSpace *vfio_get_address_space(AddressSpace *as)
>   
>   void vfio_put_address_space(VFIOAddressSpace *space)
>   {
> -    if (QLIST_EMPTY(&space->containers)) {
> -        QLIST_REMOVE(space, list);
> -        g_free(space);
> +    if (!QLIST_EMPTY(&space->containers)) {
> +        return;
>       }
> +
> +    QLIST_REMOVE(space, list);
> +    g_free(space);
> +
>       if (QLIST_EMPTY(&vfio_address_spaces)) {
>           qemu_unregister_reset(vfio_reset_handler, NULL);
>       }