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bh=e11hdfMAsAbqthJjnlCkunOgeb+RzNMnNwXR8nO0SPE=; b=eqCBhgE+yYulorcvrBssorQG7LYlSpSf3SbaQr0gxsSTOoq4TWLqq6ML+Y/5HylMr/WifZ o5bQKI3Jh++aoppaV02t0ofqbnWTDbGplJA1tCjnL3nPgsbwuUpOgh7Nn5+6CmmkUxXnwd d37IcWTB8JWdtXhpCdj7ihdiCuUVbHY= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-152-NZ6kUGCXNiKZ9Szb4vs4Og-1; Thu, 24 Sep 2020 11:02:39 -0400 X-MC-Unique: NZ6kUGCXNiKZ9Szb4vs4Og-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A11C2801E53; Thu, 24 Sep 2020 15:02:37 +0000 (UTC) Received: from gondolin (ovpn-112-247.ams2.redhat.com [10.36.112.247]) by smtp.corp.redhat.com (Postfix) with ESMTP id 897C75D9D2; Thu, 24 Sep 2020 15:02:22 +0000 (UTC) Date: Thu, 24 Sep 2020 17:02:19 +0200 From: Cornelia Huck To: Kirti Wankhede Subject: Re: [PATCH v26 05/17] vfio: Add VM state change handler to know state of VM Message-ID: <20200924170220.0a9836fe.cohuck@redhat.com> In-Reply-To: <1600817059-26721-6-git-send-email-kwankhede@nvidia.com> References: <1600817059-26721-1-git-send-email-kwankhede@nvidia.com> <1600817059-26721-6-git-send-email-kwankhede@nvidia.com> Organization: Red Hat GmbH MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=cohuck@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=63.128.21.124; envelope-from=cohuck@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/09/24 01:10:00 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -32 X-Spam_score: -3.3 X-Spam_bar: --- X-Spam_report: (-3.3 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1.199, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: cjia@nvidia.com, aik@ozlabs.ru, Zhengxiao.zx@Alibaba-inc.com, shuangtai.tst@alibaba-inc.com, qemu-devel@nongnu.org, peterx@redhat.com, eauger@redhat.com, yi.l.liu@intel.com, quintela@redhat.com, ziye.yang@intel.com, armbru@redhat.com, mlevitsk@redhat.com, pasic@linux.ibm.com, felipe@nutanix.com, zhi.a.wang@intel.com, kevin.tian@intel.com, yan.y.zhao@intel.com, dgilbert@redhat.com, alex.williamson@redhat.com, changpeng.liu@intel.com, eskultet@redhat.com, Ken.Xue@amd.com, jonathan.davies@nutanix.com, pbonzini@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, 23 Sep 2020 04:54:07 +0530 Kirti Wankhede wrote: > VM state change handler gets called on change in VM's state. This is used to set > VFIO device state to _RUNNING. > > Signed-off-by: Kirti Wankhede > Reviewed-by: Neo Jia > Reviewed-by: Dr. David Alan Gilbert > --- > hw/vfio/migration.c | 136 ++++++++++++++++++++++++++++++++++++++++++ > hw/vfio/trace-events | 3 +- > include/hw/vfio/vfio-common.h | 4 ++ > 3 files changed, 142 insertions(+), 1 deletion(-) > (...) > +static int vfio_migration_set_state(VFIODevice *vbasedev, uint32_t mask, > + uint32_t value) I think I've mentioned that before, but this function could really benefit from a comment what mask and value mean. > +{ > + VFIOMigration *migration = vbasedev->migration; > + VFIORegion *region = &migration->region; > + off_t dev_state_off = region->fd_offset + > + offsetof(struct vfio_device_migration_info, device_state); > + uint32_t device_state; > + int ret; > + > + ret = vfio_mig_read(vbasedev, &device_state, sizeof(device_state), > + dev_state_off); > + if (ret < 0) { > + return ret; > + } > + > + device_state = (device_state & mask) | value; > + > + if (!VFIO_DEVICE_STATE_VALID(device_state)) { > + return -EINVAL; > + } > + > + ret = vfio_mig_write(vbasedev, &device_state, sizeof(device_state), > + dev_state_off); > + if (ret < 0) { > + ret = vfio_mig_read(vbasedev, &device_state, sizeof(device_state), > + dev_state_off); > + if (ret < 0) { > + return ret; > + } > + > + if (VFIO_DEVICE_STATE_IS_ERROR(device_state)) { > + hw_error("%s: Device is in error state 0x%x", > + vbasedev->name, device_state); > + return -EFAULT; Is -EFAULT a good return value here? Maybe -EIO? > + } > + } > + > + vbasedev->device_state = device_state; > + trace_vfio_migration_set_state(vbasedev->name, device_state); > + return 0; > +} > + > +static void vfio_vmstate_change(void *opaque, int running, RunState state) > +{ > + VFIODevice *vbasedev = opaque; > + > + if ((vbasedev->vm_running != running)) { > + int ret; > + uint32_t value = 0, mask = 0; > + > + if (running) { > + value = VFIO_DEVICE_STATE_RUNNING; > + if (vbasedev->device_state & VFIO_DEVICE_STATE_RESUMING) { > + mask = ~VFIO_DEVICE_STATE_RESUMING; I've been staring at this for some time and I think that the desired result is - set _RUNNING - if _RESUMING was set, clear it, but leave the other bits intact - if _RESUMING was not set, clear everything previously set This would really benefit from a comment (or am I the only one struggling here?) > + } > + } else { > + mask = ~VFIO_DEVICE_STATE_RUNNING; > + } > + > + ret = vfio_migration_set_state(vbasedev, mask, value); > + if (ret) { > + /* > + * vm_state_notify() doesn't support reporting failure. If such > + * error reporting support added in furure, migration should be > + * aborted. "We should abort the migration in this case, but vm_state_notify() currently does not support reporting failures." ? Can/should we mark the failing device in some way? > + */ > + error_report("%s: Failed to set device state 0x%x", > + vbasedev->name, value & mask); > + } > + vbasedev->vm_running = running; > + trace_vfio_vmstate_change(vbasedev->name, running, RunState_str(state), > + value & mask); > + } > +} > + > static int vfio_migration_init(VFIODevice *vbasedev, > struct vfio_region_info *info) > { (...)