On 3/18/26 08:36, Duan, Zhenzhong wrote:
-----Original Message-----
From: Pierrick Bouvier <[email protected]>
Subject: [PATCH 1/2] backends/iommufd.c: report error when /dev/iommu is not
available
In case current kernel does not support /dev/iommu, qemu will probably
fail first because /sys/bus/pci/devices/*/vfio-dev/ is not present,
since QEMU opens it before /dev/iommu.
Instead, report an error directly when initializing iommufd object, to
inform user that kernel does not support it, with a hint about missing
CONFIG_IOMMUFD.
Signed-off-by: Pierrick Bouvier <[email protected]>
---
backends/iommufd.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/backends/iommufd.c b/backends/iommufd.c
index acfab907c03..c4eb3de1307 100644
--- a/backends/iommufd.c
+++ b/backends/iommufd.c
@@ -32,6 +32,11 @@ static void iommufd_backend_init(Object *obj)
{
IOMMUFDBackend *be = IOMMUFD_BACKEND(obj);
+ if (!g_file_test("/dev/iommu", G_FILE_TEST_EXISTS)) {
+ error_setg(&error_fatal, "/dev/iommu does not exist"
+ " (is your kernel config missing
CONFIG_IOMMUFD?)");
If hot add an iommufd object with object_add QMP, may this kill QEMU instance?
yes.
Unfortunately, backends are Objects. So we don't have a realize
handler and a 'Error **' parameter :/
Thanks,
C.
Thanks
Zhenzhong
+ }
+
be->fd = -1;
be->users = 0;
be->owned = true;
--
2.47.3
