From: Cornelia Huck <cohuck@redhat.com>
To: Pierre Morel <pmorel@linux.ibm.com>
Cc: Tony Krowiak <akrowiak@linux.vnet.ibm.com>,
linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org,
kvm@vger.kernel.org, freude@de.ibm.com, schwidefsky@de.ibm.com,
heiko.carstens@de.ibm.com, borntraeger@de.ibm.com,
kwankhede@nvidia.com, bjsdjshi@linux.vnet.ibm.com,
pbonzini@redhat.com, alex.williamson@redhat.com,
pmorel@linux.vnet.ibm.com, alifm@linux.vnet.ibm.com,
mjrosato@linux.vnet.ibm.com, jjherne@linux.vnet.ibm.com,
thuth@redhat.com, pasic@linux.vnet.ibm.com, berrange@redhat.com,
fiuczy@linux.vnet.ibm.com, buendgen@de.ibm.com
Subject: Re: [PATCH v5 04/13] s390: vfio-ap: base implementation of VFIO AP device driver
Date: Wed, 13 Jun 2018 14:12:21 +0200 [thread overview]
Message-ID: <20180613141221.5b924348.cohuck@redhat.com> (raw)
In-Reply-To: <7237751c-66b5-d14c-5b71-cc1cfc79db87@linux.ibm.com>
On Wed, 13 Jun 2018 14:01:54 +0200
Pierre Morel <pmorel@linux.ibm.com> wrote:
> On 13/06/2018 13:14, Cornelia Huck wrote:
> > On Wed, 13 Jun 2018 12:54:40 +0200
> > Pierre Morel <pmorel@linux.ibm.com> wrote:
> >
> >> On 13/06/2018 09:48, Cornelia Huck wrote:
> >>> On Wed, 13 Jun 2018 09:41:16 +0200
> >>> Pierre Morel <pmorel@linux.ibm.com> wrote:
> >>>
> >>>> On 07/05/2018 17:11, Tony Krowiak wrote:
> >>>>> Introduces a new AP device driver. This device driver
> >>>>> is built on the VFIO mediated device framework. The framework
> >>>>> provides sysfs interfaces that facilitate passthrough
> >>>>> access by guests to devices installed on the linux host.
> >>>> ...snip...
> >>>>
> >>>>> +static int vfio_ap_matrix_dev_create(void)
> >>>>> +{
> >>>>> + int ret;
> >>>>> +
> >>>>> + vfio_ap_root_device = root_device_register(VFIO_AP_ROOT_NAME);
> >>>>> +
> >>>>> + if (IS_ERR(vfio_ap_root_device)) {
> >>>>> + ret = PTR_ERR(vfio_ap_root_device);
> >>>>> + goto done;
> >>>>> + }
> >>>>> +
> >>>>> + ap_matrix = kzalloc(sizeof(*ap_matrix), GFP_KERNEL);
> >>>>> + if (!ap_matrix) {
> >>>>> + ret = -ENOMEM;
> >>>>> + goto matrix_alloc_err;
> >>>>> + }
> >>>>> +
> >>>>> + ap_matrix->device.type = &vfio_ap_dev_type;
> >>>>> + dev_set_name(&ap_matrix->device, "%s", VFIO_AP_DEV_NAME);
> >>>>> + ap_matrix->device.parent = vfio_ap_root_device;
> >>>>> + ap_matrix->device.release = vfio_ap_matrix_dev_release;
> >>>>> + ap_matrix->device.driver = &vfio_ap_drv.driver;
> >>>>> +
> >>>>> + ret = device_register(&ap_matrix->device);
> >>>>> + if (ret)
> >>>>> + goto matrix_reg_err;
> >>>>> +
> >>>>> + goto done;
> >>>>> +
> >>>>> +matrix_reg_err:
> >>>>> + put_device(&ap_matrix->device);
> >>>> Did not see this before but here you certainly want to
> >>>> do a kfree and not a put_device.
> >>> No, this must not be a kfree. Once you've tried to register something
> >>> embedding a struct device with the driver core, you need to use
> >>> put_device, as another path may have acquired a reference, even if
> >>> registering ultimately failed. See the comment for device_register().
> >>> IOW, the code is correct.
> >> learned something again :) ,
> >> but still, a kfree is needed for the kzalloc.
> >> Does'nt it?
> > No, the put callback for the embedding structure needs to take care of
> > freeing things. Otherwise it is buggy.
>
> Seems buggy to me.
> How does the put_device knows if it is embedded and then in what it is
> embedded ?
It does not need to know; the code registering the structure needs to
set up device->release correctly.
>
> >
> >>>
> >>>>
> >>>>> +
> >>>>> +matrix_alloc_err:
> >>>>> + root_device_unregister(vfio_ap_root_device);
> >>>>> +
> >>>>> +done:
> >>>>> + return ret;
> >>>>> +}
> >>>>> +
> >>>>> +static void vfio_ap_matrix_dev_destroy(struct ap_matrix *ap_matrix)
> >>>>> +{
> >>>>> + device_unregister(&ap_matrix->device);
> >>>>> + root_device_unregister(vfio_ap_root_device);
> >>>> Also here you need a kfree(ap_matrix) too .
> >>> Same here.
> >>>
>
>
next prev parent reply other threads:[~2018-06-13 12:12 UTC|newest]
Thread overview: 92+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-07 15:11 [PATCH v5 00/13] s390: vfio-ap: guest dedicated crypto adapters Tony Krowiak
2018-05-07 15:11 ` [PATCH v5 01/13] KVM: s390: Interface to test whether APXA installed Tony Krowiak
2018-05-16 10:21 ` Cornelia Huck
2018-05-16 10:45 ` Tony Krowiak
2018-05-17 9:11 ` Harald Freudenberger
2018-05-17 9:44 ` Cornelia Huck
2018-05-07 15:11 ` [PATCH v5 02/13] KVM: s390: refactor crypto initialization Tony Krowiak
2018-05-16 8:51 ` Pierre Morel
2018-05-16 11:14 ` Tony Krowiak
2018-05-16 12:17 ` Pierre Morel
2018-05-16 12:21 ` Cornelia Huck
2018-05-07 15:11 ` [PATCH v5 03/13] KVM: s390: CPU model support for AP virtualization Tony Krowiak
2018-05-07 15:11 ` [PATCH v5 04/13] s390: vfio-ap: base implementation of VFIO AP device driver Tony Krowiak
2018-05-16 8:21 ` Pierre Morel
2018-05-16 11:29 ` Tony Krowiak
2018-05-16 11:45 ` Tony Krowiak
2018-06-07 8:57 ` Pierre Morel
2018-06-13 7:41 ` Pierre Morel
2018-06-13 7:48 ` Cornelia Huck
2018-06-13 10:54 ` Pierre Morel
2018-06-13 11:14 ` Cornelia Huck
2018-06-13 12:01 ` Pierre Morel
2018-06-13 12:12 ` Cornelia Huck [this message]
2018-06-13 12:16 ` Pierre Morel
2018-06-14 13:04 ` Tony Krowiak
2018-05-07 15:11 ` [PATCH v5 05/13] s390: vfio-ap: register matrix device with VFIO mdev framework Tony Krowiak
2018-05-11 17:18 ` Halil Pasic
2018-05-14 19:42 ` Tony Krowiak
2018-05-15 14:17 ` Pierre Morel
2018-05-15 15:16 ` Tony Krowiak
2018-05-15 15:48 ` Halil Pasic
2018-05-15 16:11 ` Tony Krowiak
2018-05-17 7:44 ` Cornelia Huck
2018-05-21 15:13 ` Tony Krowiak
2018-05-22 8:19 ` Cornelia Huck
2018-05-22 21:41 ` Tony Krowiak
2018-05-16 10:42 ` Cornelia Huck
2018-05-16 12:48 ` Tony Krowiak
2018-05-16 12:58 ` Tony Krowiak
2018-05-07 15:11 ` [PATCH v5 06/13] KVM: s390: interfaces to manage guest's AP matrix Tony Krowiak
2018-05-11 16:08 ` Halil Pasic
2018-05-16 14:29 ` Tony Krowiak
2018-05-16 14:41 ` Pierre Morel
2018-05-21 15:23 ` Tony Krowiak
2018-05-15 14:55 ` Pierre Morel
2018-05-15 16:07 ` Tony Krowiak
2018-05-16 7:48 ` Pierre Morel
2018-05-16 13:12 ` Tony Krowiak
2018-05-16 13:15 ` Pierre Morel
2018-05-16 13:48 ` Tony Krowiak
2018-05-18 8:55 ` Pierre Morel
2018-05-23 14:29 ` Tony Krowiak
2018-05-24 7:46 ` Pierre Morel
2018-05-07 15:11 ` [PATCH v5 07/13] s390: vfio-ap: sysfs interfaces to configure adapters Tony Krowiak
2018-05-07 15:11 ` [PATCH v5 08/13] s390: vfio-ap: sysfs interfaces to configure domains Tony Krowiak
2018-05-07 15:11 ` [PATCH v5 09/13] s390: vfio-ap: sysfs interfaces to configure control domains Tony Krowiak
2018-05-07 15:11 ` [PATCH v5 10/13] s390: vfio-ap: sysfs interface to view matrix mdev matrix Tony Krowiak
2018-05-16 7:55 ` Pierre Morel
2018-05-23 14:38 ` Tony Krowiak
2018-05-24 9:10 ` Pierre Morel
2018-05-30 14:28 ` Tony Krowiak
2018-06-05 12:40 ` Pierre Morel
2018-06-06 14:24 ` Tony Krowiak
2018-06-06 15:10 ` Pierre Morel
2018-06-07 12:53 ` Tony Krowiak
2018-06-07 13:16 ` Halil Pasic
2018-06-07 14:33 ` Tony Krowiak
2018-05-07 15:11 ` [PATCH v5 11/13] KVM: s390: implement mediated device open callback Tony Krowiak
2018-05-16 8:03 ` Pierre Morel
2018-05-23 14:45 ` Tony Krowiak
2018-05-24 9:08 ` Pierre Morel
2018-05-30 14:33 ` Tony Krowiak
2018-06-05 12:19 ` Pierre Morel
2018-06-06 14:28 ` Tony Krowiak
2018-06-06 16:08 ` Pierre Morel
2018-06-06 17:40 ` Pierre Morel
2018-06-07 13:54 ` Tony Krowiak
2018-06-07 15:20 ` Pierre Morel
2018-06-07 16:30 ` Tony Krowiak
2018-06-07 17:15 ` Pierre Morel
2018-06-08 21:59 ` Tony Krowiak
2018-06-11 9:23 ` Pierre Morel
2018-06-11 11:32 ` Halil Pasic
2018-06-11 11:49 ` Janosch Frank
2018-06-11 16:26 ` Tony Krowiak
2018-06-11 16:50 ` Halil Pasic
2018-06-11 16:54 ` Tony Krowiak
2018-06-11 12:50 ` Tony Krowiak
2018-06-11 12:56 ` Tony Krowiak
2018-06-07 13:52 ` Tony Krowiak
2018-05-07 15:11 ` [PATCH v5 12/13] s390: vfio-ap: implement VFIO_DEVICE_GET_INFO ioctl Tony Krowiak
2018-05-07 15:11 ` [PATCH v5 13/13] s390: doc: detailed specifications for AP virtualization Tony Krowiak
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