From 1c729ca8860a5197da62d1fa68d6085a6ec0acd3 Mon Sep 17 00:00:00 2001 From: Zhenzhong Duan Date: Wed, 21 May 2025 19:03:01 +0800 Subject: [PATCH] vfio/iommufd: Add comment emphasizing no movement of hiod->realize() call MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The nested IOMMU support needs device and hwpt id which are generated only after attachment. Hiod encapsulates these information in realize() and passes to vIOMMU. Suggested-by: Cédric Le Goater Signed-off-by: Zhenzhong Duan Reviewed-by: Cédric Le Goater Link: https://lore.kernel.org/qemu-devel/20250521110301.3313877-1-zhenzhong.duan@intel.com Signed-off-by: Cédric Le Goater --- hw/vfio/iommufd.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/hw/vfio/iommufd.c b/hw/vfio/iommufd.c index af1c7ab10a..6b2696793f 100644 --- a/hw/vfio/iommufd.c +++ b/hw/vfio/iommufd.c @@ -592,6 +592,10 @@ found_container: goto err_listener_register; } + /* + * Do not move this code before attachment! The nested IOMMU support + * needs device and hwpt id which are generated only after attachment. + */ if (!vfio_device_hiod_create_and_realize(vbasedev, TYPE_HOST_IOMMU_DEVICE_IOMMUFD_VFIO, errp)) { goto err_listener_register; -- 2.39.5