From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 238C9C388F9 for ; Thu, 22 Oct 2020 18:59:43 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3CB9624656 for ; Thu, 22 Oct 2020 18:59:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="djzj0hUn" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3CB9624656 Authentication-Results: mail.kernel.org; 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]:50252 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kVfoL-0002YM-37 for qemu-devel@archiver.kernel.org; Thu, 22 Oct 2020 14:59:41 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:56496) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kVfgK-0006a7-Ha for qemu-devel@nongnu.org; Thu, 22 Oct 2020 14:51:24 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:20759) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kVfgH-0006l5-Jd for qemu-devel@nongnu.org; Thu, 22 Oct 2020 14:51:23 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1603392681; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=mqSdji05VzyezNfyvMtPfPWDBtwjtehJD9JR0yKy8kc=; b=djzj0hUnjsLqhc2cTBJD+jCvqF7UnSdVRZfijCcs/anGG007kaqsolgI5HzBz0M73FJNoo IONo2DCb8ucQe7OR+uspFZlbuF9a24DsjeIMhlhVwezWWase/hrtoG970SonWMmeuUybT8 YFCQIfGAll7oBvRkJv4D+ChKw9x+vwU= 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-151-Y2_iOSI5NNeRx_ner3P9kA-1; Thu, 22 Oct 2020 14:51:17 -0400 X-MC-Unique: Y2_iOSI5NNeRx_ner3P9kA-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 519D987505D; Thu, 22 Oct 2020 18:51:14 +0000 (UTC) Received: from w520.home (ovpn-112-213.phx2.redhat.com [10.3.112.213]) by smtp.corp.redhat.com (Postfix) with ESMTP id 962D919D61; Thu, 22 Oct 2020 18:51:08 +0000 (UTC) Date: Thu, 22 Oct 2020 12:51:08 -0600 From: Alex Williamson To: Kirti Wankhede Subject: Re: [PATCH v27 07/17] vfio: Register SaveVMHandlers for VFIO device Message-ID: <20201022125108.6137e462@w520.home> In-Reply-To: <1603365127-14202-8-git-send-email-kwankhede@nvidia.com> References: <1603365127-14202-1-git-send-email-kwankhede@nvidia.com> <1603365127-14202-8-git-send-email-kwankhede@nvidia.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=alex.williamson@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=216.205.24.124; envelope-from=alex.williamson@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/10/22 08:33:10 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, 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_H4=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: cohuck@redhat.com, cjia@nvidia.com, zhi.wang.linux@gmail.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, mcrossley@nvidia.com, kevin.tian@intel.com, yan.y.zhao@intel.com, dgilbert@redhat.com, changpeng.liu@intel.com, eskultet@redhat.com, Ken.Xue@amd.com, jonathan.davies@nutanix.com, pbonzini@redhat.com, dnigam@nvidia.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thu, 22 Oct 2020 16:41:57 +0530 Kirti Wankhede wrote: > Define flags to be used as delimiter in migration stream for VFIO devices. > Added .save_setup and .save_cleanup functions. Map & unmap migration > region from these functions at source during saving or pre-copy phase. > > Set VFIO device state depending on VM's state. During live migration, VM is > running when .save_setup is called, _SAVING | _RUNNING state is set for VFIO > device. During save-restore, VM is paused, _SAVING state is set for VFIO device. > > Signed-off-by: Kirti Wankhede > Reviewed-by: Neo Jia > --- > hw/vfio/migration.c | 96 ++++++++++++++++++++++++++++++++++++++++++++++++++++ > hw/vfio/trace-events | 2 ++ > 2 files changed, 98 insertions(+) > > diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c > index 7c4fa0d08ea6..2e1054bf7f43 100644 > --- a/hw/vfio/migration.c > +++ b/hw/vfio/migration.c > @@ -8,12 +8,15 @@ > */ > > #include "qemu/osdep.h" > +#include "qemu/main-loop.h" > +#include "qemu/cutils.h" > #include > > #include "sysemu/runstate.h" > #include "hw/vfio/vfio-common.h" > #include "cpu.h" > #include "migration/migration.h" > +#include "migration/vmstate.h" > #include "migration/qemu-file.h" > #include "migration/register.h" > #include "migration/blocker.h" > @@ -25,6 +28,22 @@ > #include "trace.h" > #include "hw/hw.h" > > +/* > + * Flags to be used as unique delimiters for VFIO devices in the migration > + * stream. These flags are composed as: > + * 0xffffffff => MSB 32-bit all 1s > + * 0xef10 => Magic ID, represents emulated (virtual) function IO > + * 0x0000 => 16-bits reserved for flags > + * > + * The beginning of state information is marked by _DEV_CONFIG_STATE, > + * _DEV_SETUP_STATE, or _DEV_DATA_STATE, respectively. The end of a > + * certain state information is marked by _END_OF_STATE. > + */ > +#define VFIO_MIG_FLAG_END_OF_STATE (0xffffffffef100001ULL) > +#define VFIO_MIG_FLAG_DEV_CONFIG_STATE (0xffffffffef100002ULL) > +#define VFIO_MIG_FLAG_DEV_SETUP_STATE (0xffffffffef100003ULL) > +#define VFIO_MIG_FLAG_DEV_DATA_STATE (0xffffffffef100004ULL) > + > static inline int vfio_mig_access(VFIODevice *vbasedev, void *val, int count, > off_t off, bool iswrite) > { > @@ -129,6 +148,69 @@ static int vfio_migration_set_state(VFIODevice *vbasedev, uint32_t mask, > return 0; > } > > +/* ---------------------------------------------------------------------- */ > + > +static int vfio_save_setup(QEMUFile *f, void *opaque) > +{ > + VFIODevice *vbasedev = opaque; > + VFIOMigration *migration = vbasedev->migration; > + int ret; > + > + trace_vfio_save_setup(vbasedev->name); > + > + qemu_put_be64(f, VFIO_MIG_FLAG_DEV_SETUP_STATE); > + > + if (migration->region.mmaps) { > + /* > + * vfio_region_mmap() called from migration thread. Memory API called > + * from vfio_regio_mmap() need it when called from outdide the main loop > + * thread. > + */ Thanks for adding this detail, maybe refine slightly as: Calling vfio_region_mmap() from migration thread. Memory APIs called from this function require locking the iothread when called from outside the main loop thread. Does that capture the intent? > + qemu_mutex_lock_iothread(); > + ret = vfio_region_mmap(&migration->region); > + qemu_mutex_unlock_iothread(); > + if (ret) { > + error_report("%s: Failed to mmap VFIO migration region: %s", > + vbasedev->name, strerror(-ret)); > + error_report("%s: Falling back to slow path", vbasedev->name); > + } > + } > + > + ret = vfio_migration_set_state(vbasedev, VFIO_DEVICE_STATE_MASK, > + VFIO_DEVICE_STATE_SAVING); > + if (ret) { > + error_report("%s: Failed to set state SAVING", vbasedev->name); > + return ret; > + } > + > + qemu_put_be64(f, VFIO_MIG_FLAG_END_OF_STATE); > + > + ret = qemu_file_get_error(f); > + if (ret) { > + return ret; > + } > + > + return 0; > +} > + > +static void vfio_save_cleanup(void *opaque) > +{ > + VFIODevice *vbasedev = opaque; > + VFIOMigration *migration = vbasedev->migration; > + > + if (migration->region.mmaps) { > + vfio_region_unmap(&migration->region); > + } Are we in a different thread context here that we don't need that same iothread locking? > + trace_vfio_save_cleanup(vbasedev->name); > +} > + > +static SaveVMHandlers savevm_vfio_handlers = { > + .save_setup = vfio_save_setup, > + .save_cleanup = vfio_save_cleanup, > +}; > + > +/* ---------------------------------------------------------------------- */ > + > static void vfio_vmstate_change(void *opaque, int running, RunState state) > { > VFIODevice *vbasedev = opaque; > @@ -219,6 +301,8 @@ static int vfio_migration_init(VFIODevice *vbasedev, > int ret; > Object *obj; > VFIOMigration *migration; > + char id[256] = ""; > + g_autofree char *path = NULL, *oid; AIUI, oid must also be initialized as a g_autofree variable. > > if (!vbasedev->ops->vfio_get_object) { > return -EINVAL; > @@ -248,6 +332,18 @@ static int vfio_migration_init(VFIODevice *vbasedev, > > vbasedev->migration = migration; > migration->vbasedev = vbasedev; > + > + oid = vmstate_if_get_id(VMSTATE_IF(DEVICE(obj))); > + if (oid) { > + path = g_strdup_printf("%s/vfio", oid); > + } else { > + path = g_strdup("vfio"); If we get here then all vfio devices have the same id string. Isn't that a problem? Thanks, Alex > + } > + strpadcpy(id, sizeof(id), path, '\0'); > + > + register_savevm_live(id, VMSTATE_INSTANCE_ID_ANY, 1, &savevm_vfio_handlers, > + vbasedev); > + > migration->vm_state = qemu_add_vm_change_state_handler(vfio_vmstate_change, > vbasedev); > migration->migration_state.notify = vfio_migration_state_notifier; > diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events > index 78d7d83b5ef8..f148b5e828c1 100644 > --- a/hw/vfio/trace-events > +++ b/hw/vfio/trace-events > @@ -151,3 +151,5 @@ vfio_migration_probe(const char *name, uint32_t index) " (%s) Region %d" > vfio_migration_set_state(const char *name, uint32_t state) " (%s) state %d" > vfio_vmstate_change(const char *name, int running, const char *reason, uint32_t dev_state) " (%s) running %d reason %s device state %d" > vfio_migration_state_notifier(const char *name, const char *state) " (%s) state %s" > +vfio_save_setup(const char *name) " (%s)" > +vfio_save_cleanup(const char *name) " (%s)"