>-----Original Message-----
>From: Steven Sistare <[email protected]>
>Subject: Re: [PATCH V4 04/43] vfio/pci: vfio_pci_put_device on failure
>
>On 6/3/2025 11:55 PM, Duan, Zhenzhong wrote:
>>> -----Original Message-----
>>> From: Steven Sistare <[email protected]>
>>> Subject: Re: [PATCH V4 04/43] vfio/pci: vfio_pci_put_device on failure
>>>
>>> On 6/3/2025 6:40 AM, Duan, Zhenzhong wrote:
>>>>> -----Original Message-----
>>>>> From: Steve Sistare <[email protected]>
>>>>> Subject: [PATCH V4 04/43] vfio/pci: vfio_pci_put_device on failure
>>>>>
>>>>> If vfio_realize fails after vfio_device_attach, it should call
>>>>> vfio_device_detach during error recovery. If it fails after
>>>>> vfio_device_get_name, it should free vbasedev->name. If it fails
>>>>> after vfio_pci_config_setup, it should free vdev->msix.
>>>>>
>>>>> To fix all, call vfio_pci_put_device().
>>>>>
>>>>> Signed-off-by: Steve Sistare <[email protected]>
>>>>> ---
>>>>> hw/vfio/pci.c | 1 +
>>>>> 1 file changed, 1 insertion(+)
>>>>>
>>>>> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
>>>>> index a1bfdfe..7d3b9ff 100644
>>>>> --- a/hw/vfio/pci.c
>>>>> +++ b/hw/vfio/pci.c
>>>>> @@ -3296,6 +3296,7 @@ out_teardown:
>>>>> vfio_bars_exit(vdev);
>>>>> error:
>>>>> error_prepend(errp, VFIO_MSG_PREFIX, vbasedev->name);
>>>>> + vfio_pci_put_device(vdev);
>>>>
>>>> Double free, vfio_pci_put_device() is also called in
>>>> vfio_instance_finalize().
>>>
>>> If vfio_realize fails with an error, vfio_instance_finalize is not called.
>>> I tested that.
>>
>> Have you tried with hot plugged device?
>
>Not before, but I just tried it now, thanks for the suggestion.
>Same result -- vfio_instance_finalize is not called.
That's strange, I tried below change with hotplug a device through qmp, I see
"vfio_instance_finalize called"
device_add vfio-pci,host=04:10.1,id=vfio0,bus=root0,iommufd=iommufd0
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -3167,6 +3167,9 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
trace_vfio_mdev(vbasedev->name, vbasedev->mdev);
+error_setg(errp, "faking error in vfio_realize");
+goto error;
+
if (vbasedev->ram_block_discard_allowed && !vbasedev->mdev) {
error_setg(errp, "x-balloon-allowed only potentially compatible "
"with mdev devices");
@@ -3301,6 +3304,8 @@ error:
static void vfio_instance_finalize(Object *obj)
{
VFIOPCIDevice *vdev = VFIO_PCI_BASE(obj);
+printf("vfio_instance_finalize called\n");
+exit(1);
vfio_display_finalize(vdev);
vfio_bars_finalize(vdev);
