[Qemu-devel] [PATCH] vfio: Fix BAR->VFIODevice translation in vfio_bar_read/write

[Jan Kiszka <jan.kiszka@siemens.com>]

DO_UPCAST is supposed to translate from the first member of a struct to
that struct, not from arbitrary ones. And it (usually) breaks the build
when neglecting this rule. Use container_of to fix the build breakage
and likely also the runtime behavior.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 hw/vfio_pci.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/hw/vfio_pci.c b/hw/vfio_pci.c
index a1eeced..d36d50e 100644
--- a/hw/vfio_pci.c
+++ b/hw/vfio_pci.c
@@ -601,7 +601,7 @@ static void vfio_bar_write(void *opaque, target_phys_addr_t addr,
      * which access will service the interrupt, so we're potentially
      * getting quite a few host interrupts per guest interrupt.
      */
-    vfio_eoi(DO_UPCAST(VFIODevice, bars[bar->nr], bar));
+    vfio_eoi(container_of(bar, VFIODevice, bars[bar->nr]));
 }
 
 static uint64_t vfio_bar_read(void *opaque,
@@ -641,7 +641,7 @@ static uint64_t vfio_bar_read(void *opaque,
             __func__, bar->nr, addr, size, data);
 
     /* Same as write above */
-    vfio_eoi(DO_UPCAST(VFIODevice, bars[bar->nr], bar));
+    vfio_eoi(container_of(bar, VFIODevice, bars[bar->nr]));
 
     return data;
 }
-- 
1.7.3.4