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dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:54962 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kNDUx-0002RD-6U for qemu-devel@archiver.kernel.org; Tue, 29 Sep 2020 07:08:43 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:57248) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kNDQ1-0005FK-9D for qemu-devel@nongnu.org; Tue, 29 Sep 2020 07:03:37 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:38079) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kNDPz-0002rf-BG for qemu-devel@nongnu.org; Tue, 29 Sep 2020 07:03:36 -0400 Dkim-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1601377414; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=8iVaPevfbtqr+4yOyxmAPVmCMQ7qa9hFmw6lRqdlNYw=; b=Z6WE945045Zvg89ezP89y/VlpJ8EevRFnVCNCOU/b3S1GonXoveR2K5vvDzMxfXvOy9/9c 9loS+/xkeehjCgW+znFj2Au1uPQbPEGKlOIgqzmeJTNBYjs6rP5VMMQJRxiqm7YQs8XIZW dxVhbEsWKNQ+5j/uMoeGs/TyfXs/WTo= 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-391-bM_UNyZ-Ok226yUSle0OSQ-1; Tue, 29 Sep 2020 07:03:30 -0400 X-MC-Unique: bM_UNyZ-Ok226yUSle0OSQ-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 62520186842D; Tue, 29 Sep 2020 11:03:28 +0000 (UTC) Received: from work-vm (ovpn-114-253.ams2.redhat.com [10.36.114.253]) by smtp.corp.redhat.com (Postfix) with ESMTPS id BA6E85D9CA; Tue, 29 Sep 2020 11:03:14 +0000 (UTC) Date: Tue, 29 Sep 2020 12:03:12 +0100 From: "Dr. David Alan Gilbert" To: Cornelia Huck Subject: Re: [PATCH v26 05/17] vfio: Add VM state change handler to know state of VM Message-ID: <20200929110312.GF2826@work-vm> References: <1600817059-26721-1-git-send-email-kwankhede@nvidia.com> <1600817059-26721-6-git-send-email-kwankhede@nvidia.com> <20200924170220.0a9836fe.cohuck@redhat.com> MIME-Version: 1.0 In-Reply-To: <20200924170220.0a9836fe.cohuck@redhat.com> User-Agent: Mutt/1.14.6 (2020-07-11) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dgilbert@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Received-SPF: pass client-ip=216.205.24.124; envelope-from=dgilbert@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/09/29 02:22:44 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.687, 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, Kirti Wankhede , 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, 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" * Cornelia Huck (cohuck@redhat.com) wrote: > 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? I think you can call qemu_file_set_error on the migration stream to force an error. Dave > > + */ > > + 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) > > { > > (...) -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK