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Herne" , linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: borntraeger@de.ibm.com, mjrosato@linux.ibm.com, pasic@linux.ibm.com, alex@shazbot.org, kwankhede@nvidia.com, fiuczy@linux.ibm.com, pbonzini@redhat.com, frankja@linux.ibm.com, imbrenda@linux.ibm.com, agordeev@linux.ibm.com, hca@linux.ibm.com, gor@linux.ibm.com References: <20260807221834.562851-1-akrowiak@linux.ibm.com> <20260807221834.562851-15-akrowiak@linux.ibm.com> <8b8dc348-ac31-4dbe-a518-9563d5414f09@linux.ibm.com> Content-Language: en-US From: Anthony Krowiak In-Reply-To: <8b8dc348-ac31-4dbe-a518-9563d5414f09@linux.ibm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-Spam-Info: AW1haW4tMjYxMDA3MDA0OCBTYWx0ZWRfXyWGCSb1DwN4B W43Me398UhcyI1+tt/pyMh3PDkvI20RcpiOOKamD783aPQMQlErKwHFSD/3T9FFJ3TvD4X/z0vE eKxM8qekhtiBuivO4StsiwU94DPfbb8= X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYxMDA3MDA0OCBTYWx0ZWRfX1pZr28jah2fO SGA78iSjdQdtYcpso/efUJR3++MMXWDZPIKiSskHr6HqIIThJ07kRR2lyfJOX4yXBu9zuBTAQtM SwrULto+sKOwRMnIoW9/HqjcPrxvwVfToJoQj3Xrcy6zmXtX4IL3PMy4gfnLEY6Qde5J0NddZ4p YllUIOCwBG9RAlcI1VswWnDcR8Bt00M/KodaGgkGiO4YDYwo6BKtRPKcdqTGWtmIjY1VOQkoKXk +urqu32Z0B2tXhL6in9hwAXxLldmn+tD22/JLPRfL5BC7XTx43XQ7+PLIOwe3IxcVbyMCM7DPKr lqE2pBbquk/VqQBF+dRbrEUT/8Comfs2Xw/Eb3hnrNHfdN15n92dVi6193M4WiMvV/cF1X0iab9 9N+rv4zsGH5mQXTyd8gwrJRCVFTTm8yIyNjfWiBBr95VYSGMLlMkNgEi8WVJ1+KBwfY8MyjVYFv EGRnfdNdhexYDSZN+BQ== X-Proofpoint-GUID: F7R09YOK10rAc8pjJIWzD_wfBnm8eEAm X-Proofpoint-ORIG-GUID: F7R09YOK10rAc8pjJIWzD_wfBnm8eEAm X-Authority-Analysis: v=2.4 cv=B7osQ+tM c=1 sm=1 tr=0 ts=6ac635c5 cx=c_pps a=5BHTudwdYE3Te8bg5FgnPg==:117 a=5BHTudwdYE3Te8bg5FgnPg==:17 a=IkcTkHD0fZMA:10 a=660iZSQnnn4A:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=uAbxVGIbfxUO_5tXvNgY:22 a=VnNF1IyMAAAA:8 a=qnWB845URLmzp39-Ai4A:9 a=3ZKOabzyN94A:10 a=QEXdDO2ut3YA:10 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1176,Hydra:6.1.134,FMLib:17.12.100.49 definitions=2026-10-07_04,2026-10-06_03,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 bulkscore=0 malwarescore=0 impostorscore=0 phishscore=0 clxscore=1015 spamscore=0 adultscore=0 lowpriorityscore=0 suspectscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2609040000 definitions=main-2610070048 On 8/20/26 9:01 AM, Jason J. Herne wrote: > > > On 8/7/26 6:18 PM, Anthony Krowiak wrote: >> Add the 'migratable' feature to the features provided by the sysfs >> /sys/devices/vfio_ap/matrix/feature attribute to indicate that migration >> of vfio devices is supported. Since live guest migration is not >> supported >> for SE guests, the 'migratable' feature will not be included when the >> feature attribute is displayed. >> >> Signed-off-by: Anthony Krowiak >> --- >>   drivers/s390/crypto/vfio_ap_drv.c | 14 +++++++++++++- >>   1 file changed, 13 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/s390/crypto/vfio_ap_drv.c >> b/drivers/s390/crypto/vfio_ap_drv.c >> index 8e69ed286bb9..abfb34421d74 100644 >> --- a/drivers/s390/crypto/vfio_ap_drv.c >> +++ b/drivers/s390/crypto/vfio_ap_drv.c >> @@ -26,9 +26,21 @@ MODULE_LICENSE("GPL v2"); >>   struct ap_matrix_dev *matrix_dev; >>   debug_info_t *vfio_ap_dbf_info; >>   +#define VFIO_AP_DRV_FEATURES    "guest_matrix hotplug ap_config >> migratable" >> +#define SE_GUEST_FEATURES    "guest_matrix hotplug ap_config" >> + >>   static ssize_t features_show(struct device *dev, struct >> device_attribute *attr, char *buf) >>   { >> -    return sysfs_emit(buf, "guest_matrix hotplug ap_config\n"); >> +    /* >> +     * If the system running is an SE guest, it will support a >> different >> +     * set of features; for example, it will not support live guest >> +     * migration >> +     */ >> +    if (ap_is_se_guest()) >> +        return sysfs_emit(buf, "%s\n", SE_GUEST_FEATURES); > > ap_is_se_guest() is defined like this: > is_prot_virt_guest() && ap_sb_available(); > > is_prot_virt_guest() makes sense, this tells is this is actually a > secured guest. > > But ap_sb_available() "Returns 1 if secure binding facility is > available". > > What do we want to happen here if is_prot_virt_guest() = TRUE while > ap_sb_available() = FALSE? Have you considered this scenario? > > Also, the code would be a bit more extendible if you emitted the > static string of always supported features, and then if(se) emit the > string of se support features prepended with a space. Then new feature > updates only have a single string to modify, so no risk of > accidentally missing one. Is this what you had in mind? #define VFIO_AP_BASE_FEATURES "guest_matrix hotplug ap_config" #define VFIO_AP_SE_EXCLUDED_FEATURES "migration" if (ap_is_se_guest)     sysfs_emit(buf, "%s\n", VFIO_AP_BASE_FEATURES); else     sysfs_emit(buf, "%s %s\n", VFIO_AP_SE_EXCLUDED_FEATURES); > > Also, I'd consider using "migrate" or "migration" as they match > existing feature designations better. We did not use hotpluggable :) > >> + >> +    /* Return all features supported by the vfio_ap device driver */ >> +    return sysfs_emit(buf, "%s\n", VFIO_AP_DRV_FEATURES); >>   } >>   static DEVICE_ATTR_RO(features); > >