> -----Original Message----- > From: Jason Gunthorpe [mailto:jgg@xxxxxxxxxx] > Sent: 28 February 2022 14:58 > To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@xxxxxxxxxx> > Cc: kvm@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > linux-crypto@xxxxxxxxxxxxxxx; alex.williamson@xxxxxxxxxx; > cohuck@xxxxxxxxxx; mgurtovoy@xxxxxxxxxx; yishaih@xxxxxxxxxx; Linuxarm > <linuxarm@xxxxxxxxxx>; liulongfang <liulongfang@xxxxxxxxxx>; Zengtao (B) > <prime.zeng@xxxxxxxxxxxxx>; Jonathan Cameron > <jonathan.cameron@xxxxxxxxxx>; Wangzhou (B) <wangzhou1@xxxxxxxxxxxxx> > Subject: Re: [PATCH v6 09/10] hisi_acc_vfio_pci: Add support for VFIO live > migration > > On Mon, Feb 28, 2022 at 09:01:20AM +0000, Shameer Kolothum wrote: > > > +static int hisi_acc_vf_stop_copy(struct hisi_acc_vf_core_device > *hisi_acc_vdev, > > + struct hisi_acc_vf_migration_file *migf) > > +{ > > + struct acc_vf_data *vf_data = &migf->vf_data; > > This now needs to hold the migf->lock > > > + > > + if ((cur == VFIO_DEVICE_STATE_STOP || cur == > VFIO_DEVICE_STATE_PRE_COPY) && > > + new == VFIO_DEVICE_STATE_RUNNING) { > > + hisi_acc_vf_start_device(hisi_acc_vdev); > > This should be two stanzas STOP->RUNNING should do start_device > > And PRE_COPY->RUNNING should do disable_fds, and presumably nothing > else - the device was never stopped. > Ok. I will take care of all the above. > > + } else if (cmd == VFIO_DEVICE_MIG_PRECOPY) { > > + struct vfio_device_mig_precopy precopy; > > + enum vfio_device_mig_state curr_state; > > + unsigned long minsz; > > + int ret; > > + > > + minsz = offsetofend(struct vfio_device_mig_precopy, dirty_bytes); > > + > > + if (copy_from_user(&precopy, (void __user *)arg, minsz)) > > + return -EFAULT; > > + if (precopy.argsz < minsz) > > + return -EINVAL; > > + > > + ret = hisi_acc_vfio_pci_get_device_state(core_vdev, &curr_state); > > + if (!ret && curr_state == VFIO_DEVICE_STATE_PRE_COPY) { > > + precopy.initial_bytes = QM_MATCH_SIZE; > > + precopy.dirty_bytes = QM_MATCH_SIZE; > > dirty_bytes should be 0 > > initial_bytes should be calculated based on the current file > descriptor offset. > > The use of curr_state should be eliminated > > This ioctl should be on the saving file_operations, not here > > + * This ioctl is used on the migration data FD in the precopy phase of the > + * migration data transfer. It returns an estimate of the current data sizes > > I see there is a bug in the qemu version: > > @@ -215,12 +218,13 @@ static void vfio_save_precopy_pending(QEMUFile > *f, void *> > uint64_t *res_postcopy_only) > { > VFIODevice *vbasedev = opaque; > + VFIOMigration *migration = vbasedev->migration; > struct vfio_device_mig_precopy precopy = { > .argsz = sizeof(precopy), > }; > int ret; > > - ret = ioctl(vbasedev->fd, VFIO_DEVICE_MIG_PRECOPY, &precopy); > + ret = ioctl(migration->data_fd, VFIO_DEVICE_MIG_PRECOPY, &precopy); > if (ret) { > return; > } > > I'll update my github. Ok. Thanks for that. And for the VFIO_DEVICE_MIG_PRECOPY ioctl, this is what I have now, +static long hisi_acc_vf_save_unl_ioctl(struct file *filp, + unsigned int cmd, unsigned long arg) +{ + struct hisi_acc_vf_migration_file *migf = filp->private_data; + loff_t *pos = &filp->f_pos; + struct vfio_device_mig_precopy precopy; + unsigned long minsz; + + if (cmd != VFIO_DEVICE_MIG_PRECOPY) + return -EINVAL; + + minsz = offsetofend(struct vfio_device_mig_precopy, dirty_bytes); + + if (copy_from_user(&precopy, (void __user *)arg, minsz)) + return -EFAULT; + if (precopy.argsz < minsz) + return -EINVAL; + + mutex_lock(&migf->lock); + if (*pos > migf->total_length) { + mutex_unlock(&migf->lock); + return -EINVAL; + } + + precopy.dirty_bytes = 0; + precopy.initial_bytes = migf->total_length - *pos; + mutex_unlock(&migf->lock); + return copy_to_user((void __user *)arg, &precopy, minsz) ? -EFAULT : 0; +} + I had a quick run with the above Qemu changes, and looks ok. Please let me know. Thanks, Shameer
