From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:28770 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2502451AbgLNTkH (ORCPT ); Mon, 14 Dec 2020 14:40:07 -0500 Subject: Re: [PATCH v3] s390/vfio-ap: clean up vfio_ap resources when KVM pointer invalidated References: <20201214165617.28685-1-akrowiak@linux.ibm.com> From: Tony Krowiak Message-ID: <237fe6d3-ebcc-1046-b295-a0154ce1158e@linux.ibm.com> Date: Mon, 14 Dec 2020 14:39:17 -0500 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US List-ID: To: Greg KH Cc: linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, stable@vger.kernel.org, sashal@kernel.org, borntraeger@de.ibm.com, cohuck@redhat.com, kwankhede@nvidia.com, pbonzini@redhat.com, alex.williamson@redhat.com, pasic@linux.vnet.ibm.com On 12/14/20 12:07 PM, Greg KH wrote: > On Mon, Dec 14, 2020 at 11:56:17AM -0500, Tony Krowiak wrote: >> The vfio_ap device driver registers a group notifier with VFIO when the >> file descriptor for a VFIO mediated device for a KVM guest is opened to >> receive notification that the KVM pointer is set (VFIO_GROUP_NOTIFY_SET_KVM >> event). When the KVM pointer is set, the vfio_ap driver takes the >> following actions: >> 1. Stashes the KVM pointer in the vfio_ap_mdev struct that holds the state >> of the mediated device. >> 2. Calls the kvm_get_kvm() function to increment its reference counter. >> 3. Sets the function pointer to the function that handles interception of >> the instruction that enables/disables interrupt processing. >> 4. Sets the masks in the KVM guest's CRYCB to pass AP resources through to >> the guest. >> >> In order to avoid memory leaks, when the notifier is called to receive >> notification that the KVM pointer has been set to NULL, the vfio_ap device >> driver should reverse the actions taken when the KVM pointer was set. >> >> Fixes: 258287c994de ("s390: vfio-ap: implement mediated device open callback") >> Signed-off-by: Tony Krowiak >> --- >> drivers/s390/crypto/vfio_ap_ops.c | 29 ++++++++++++++++++++--------- >> 1 file changed, 20 insertions(+), 9 deletions(-) > > > This is not the correct way to submit patches for inclusion in the > stable kernel tree. Please read: > https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html > for how to do this properly. > > I read the document on the correct way to submit patches for inclusion in the stable kernel. I apologize for my ignorance, but I don't see the problem. Can you help me out here? Does a patch that fixes a memory leak not qualify or is it something else?