From patchwork Mon May 4 15:58:53 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kirti Wankhede X-Patchwork-Id: 283453 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=-9.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 9B1BAC3A5A9 for ; Mon, 4 May 2020 16:40:09 +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 5724420746 for ; Mon, 4 May 2020 16:40:09 +0000 (UTC) Authentication-Results: mail.kernel.org; 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Mon, 04 May 2020 12:37:26 -0400 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate26.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Mon, 04 May 2020 09:32:09 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Mon, 04 May 2020 09:32:22 -0700 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Mon, 04 May 2020 09:32:22 -0700 Received: from HQMAIL101.nvidia.com (172.20.187.10) by HQMAIL105.nvidia.com (172.20.187.12) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Mon, 4 May 2020 16:32:21 +0000 Received: from kwankhede-dev.nvidia.com (10.124.1.5) by HQMAIL101.nvidia.com (172.20.187.10) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Mon, 4 May 2020 16:32:15 +0000 From: Kirti Wankhede To: , Subject: [PATCH Kernel v18 1/7] vfio: UAPI for migration interface for device state Date: Mon, 4 May 2020 21:28:53 +0530 Message-ID: <1588607939-26441-2-git-send-email-kwankhede@nvidia.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1588607939-26441-1-git-send-email-kwankhede@nvidia.com> References: <1588607939-26441-1-git-send-email-kwankhede@nvidia.com> X-NVConfidentiality: public MIME-Version: 1.0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1588609929; bh=s4Iv0GJDj+1bhl4jbE8YcxRvsfl81dyjXBeOzB1RdI0=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:X-NVConfidentiality:MIME-Version: Content-Type; b=ovmFnVyohig/KuDQa0HbHvS3tH9giqkbs+jnwIAumdMc+gtv0Pay7ojojQjiXfbYc V+K1I093YciTBciEAX1IwFZyY1FC3zBtoWA5u9bdVGnIYmcUAvdOdqJSdtooFGZYdg bi6VPuPvkyxZcC59zAk+pGF4lH+bEs/Y/oKUKHVW/s5jz/7HX71ox0ptP7ZO+wvw6R DQ/3z2njIEa8gLCovOTlECn0PRhUXjO9mEadLMJ0pPmxNUqK9I4LiaBnT8tyMQYKuc jONXh3kiHRP9P3GdWQvZ+QQ0eJX/XijHBC3psDQfNytAf+vOIXDCdVAnmummCVcx35 NzN/Sc92dFLAQ== Received-SPF: pass client-ip=216.228.121.65; envelope-from=kwankhede@nvidia.com; helo=hqnvemgate26.nvidia.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/05/04 12:32:22 X-ACL-Warn: Detected OS = Windows 7 or 8 [fuzzy] X-Spam_score_int: -70 X-Spam_score: -7.1 X-Spam_bar: ------- X-Spam_report: (-7.1 / 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_HI=-5, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN 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: Zhengxiao.zx@Alibaba-inc.com, kevin.tian@intel.com, yi.l.liu@intel.com, yan.y.zhao@intel.com, kvm@vger.kernel.org, eskultet@redhat.com, ziye.yang@intel.com, qemu-devel@nongnu.org, cohuck@redhat.com, shuangtai.tst@alibaba-inc.com, dgilbert@redhat.com, zhi.a.wang@intel.com, mlevitsk@redhat.com, pasic@linux.ibm.com, aik@ozlabs.ru, Kirti Wankhede , eauger@redhat.com, felipe@nutanix.com, jonathan.davies@nutanix.com, changpeng.liu@intel.com, Ken.Xue@amd.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" - Defined MIGRATION region type and sub-type. - Defined vfio_device_migration_info structure which will be placed at the 0th offset of migration region to get/set VFIO device related information. Defined members of structure and usage on read/write access. - Defined device states and state transition details. - Defined sequence to be followed while saving and resuming VFIO device. Signed-off-by: Kirti Wankhede Reviewed-by: Neo Jia --- include/uapi/linux/vfio.h | 228 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 228 insertions(+) diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h index 015516bcfaa3..ad9bb5af3463 100644 --- a/include/uapi/linux/vfio.h +++ b/include/uapi/linux/vfio.h @@ -305,6 +305,7 @@ struct vfio_region_info_cap_type { #define VFIO_REGION_TYPE_PCI_VENDOR_MASK (0xffff) #define VFIO_REGION_TYPE_GFX (1) #define VFIO_REGION_TYPE_CCW (2) +#define VFIO_REGION_TYPE_MIGRATION (3) /* sub-types for VFIO_REGION_TYPE_PCI_* */ @@ -379,6 +380,233 @@ struct vfio_region_gfx_edid { /* sub-types for VFIO_REGION_TYPE_CCW */ #define VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD (1) +/* sub-types for VFIO_REGION_TYPE_MIGRATION */ +#define VFIO_REGION_SUBTYPE_MIGRATION (1) + +/* + * The structure vfio_device_migration_info is placed at the 0th offset of + * the VFIO_REGION_SUBTYPE_MIGRATION region to get and set VFIO device related + * migration information. Field accesses from this structure are only supported + * at their native width and alignment. Otherwise, the result is undefined and + * vendor drivers should return an error. + * + * device_state: (read/write) + * - The user application writes to this field to inform the vendor driver + * about the device state to be transitioned to. + * - The vendor driver should take the necessary actions to change the + * device state. After successful transition to a given state, the + * vendor driver should return success on write(device_state, state) + * system call. If the device state transition fails, the vendor driver + * should return an appropriate -errno for the fault condition. + * - On the user application side, if the device state transition fails, + * that is, if write(device_state, state) returns an error, read + * device_state again to determine the current state of the device from + * the vendor driver. + * - The vendor driver should return previous state of the device unless + * the vendor driver has encountered an internal error, in which case + * the vendor driver may report the device_state VFIO_DEVICE_STATE_ERROR. + * - The user application must use the device reset ioctl to recover the + * device from VFIO_DEVICE_STATE_ERROR state. If the device is + * indicated to be in a valid device state by reading device_state, the + * user application may attempt to transition the device to any valid + * state reachable from the current state or terminate itself. + * + * device_state consists of 3 bits: + * - If bit 0 is set, it indicates the _RUNNING state. If bit 0 is clear, + * it indicates the _STOP state. When the device state is changed to + * _STOP, driver should stop the device before write() returns. + * - If bit 1 is set, it indicates the _SAVING state, which means that the + * driver should start gathering device state information that will be + * provided to the VFIO user application to save the device's state. + * - If bit 2 is set, it indicates the _RESUMING state, which means that + * the driver should prepare to resume the device. Data provided through + * the migration region should be used to resume the device. + * Bits 3 - 31 are reserved for future use. To preserve them, the user + * application should perform a read-modify-write operation on this + * field when modifying the specified bits. + * + * +------- _RESUMING + * |+------ _SAVING + * ||+----- _RUNNING + * ||| + * 000b => Device Stopped, not saving or resuming + * 001b => Device running, which is the default state + * 010b => Stop the device & save the device state, stop-and-copy state + * 011b => Device running and save the device state, pre-copy state + * 100b => Device stopped and the device state is resuming + * 101b => Invalid state + * 110b => Error state + * 111b => Invalid state + * + * State transitions: + * + * _RESUMING _RUNNING Pre-copy Stop-and-copy _STOP + * (100b) (001b) (011b) (010b) (000b) + * 0. Running or default state + * | + * + * 1. Normal Shutdown (optional) + * |------------------------------------->| + * + * 2. Save the state or suspend + * |------------------------->|---------->| + * + * 3. Save the state during live migration + * |----------->|------------>|---------->| + * + * 4. Resuming + * |<---------| + * + * 5. Resumed + * |--------->| + * + * 0. Default state of VFIO device is _RUNNNG when the user application starts. + * 1. During normal shutdown of the user application, the user application may + * optionally change the VFIO device state from _RUNNING to _STOP. This + * transition is optional. The vendor driver must support this transition but + * must not require it. + * 2. When the user application saves state or suspends the application, the + * device state transitions from _RUNNING to stop-and-copy and then to _STOP. + * On state transition from _RUNNING to stop-and-copy, driver must stop the + * device, save the device state and send it to the application through the + * migration region. The sequence to be followed for such transition is given + * below. + * 3. In live migration of user application, the state transitions from _RUNNING + * to pre-copy, to stop-and-copy, and to _STOP. + * On state transition from _RUNNING to pre-copy, the driver should start + * gathering the device state while the application is still running and send + * the device state data to application through the migration region. + * On state transition from pre-copy to stop-and-copy, the driver must stop + * the device, save the device state and send it to the user application + * through the migration region. + * Vendor drivers must support the pre-copy state even for implementations + * where no data is provided to the user before the stop-and-copy state. The + * user must not be required to consume all migration data before the device + * transitions to a new state, including the stop-and-copy state. + * The sequence to be followed for above two transitions is given below. + * 4. To start the resuming phase, the device state should be transitioned from + * the _RUNNING to the _RESUMING state. + * In the _RESUMING state, the driver should use the device state data + * received through the migration region to resume the device. + * 5. After providing saved device data to the driver, the application should + * change the state from _RESUMING to _RUNNING. + * + * reserved: + * Reads on this field return zero and writes are ignored. + * + * pending_bytes: (read only) + * The number of pending bytes still to be migrated from the vendor driver. + * + * data_offset: (read only) + * The user application should read data_offset field from the migration + * region. The user application should read the device data from this + * offset within the migration region during the _SAVING state or write + * the device data during the _RESUMING state. See below for details of + * sequence to be followed. + * + * data_size: (read/write) + * The user application should read data_size to get the size in bytes of + * the data copied in the migration region during the _SAVING state and + * write the size in bytes of the data copied in the migration region + * during the _RESUMING state. + * + * The format of the migration region is as follows: + * ------------------------------------------------------------------ + * |vfio_device_migration_info| data section | + * | | /////////////////////////////// | + * ------------------------------------------------------------------ + * ^ ^ + * offset 0-trapped part data_offset + * + * The structure vfio_device_migration_info is always followed by the data + * section in the region, so data_offset will always be nonzero. The offset + * from where the data is copied is decided by the kernel driver. The data + * section can be trapped, mmapped, or partitioned, depending on how the kernel + * driver defines the data section. The data section partition can be defined + * as mapped by the sparse mmap capability. If mmapped, data_offset must be + * page aligned, whereas initial section which contains the + * vfio_device_migration_info structure, might not end at the offset, which is + * page aligned. The user is not required to access through mmap regardless + * of the capabilities of the region mmap. + * The vendor driver should determine whether and how to partition the data + * section. The vendor driver should return data_offset accordingly. + * + * The sequence to be followed while in pre-copy state and stop-and-copy state + * is as follows: + * a. Read pending_bytes, indicating the start of a new iteration to get device + * data. Repeated read on pending_bytes at this stage should have no side + * effects. + * If pending_bytes == 0, the user application should not iterate to get data + * for that device. + * If pending_bytes > 0, perform the following steps. + * b. Read data_offset, indicating that the vendor driver should make data + * available through the data section. The vendor driver should return this + * read operation only after data is available from (region + data_offset) + * to (region + data_offset + data_size). + * c. Read data_size, which is the amount of data in bytes available through + * the migration region. + * Read on data_offset and data_size should return the offset and size of + * the current buffer if the user application reads data_offset and + * data_size more than once here. + * d. Read data_size bytes of data from (region + data_offset) from the + * migration region. + * e. Process the data. + * f. Read pending_bytes, which indicates that the data from the previous + * iteration has been read. If pending_bytes > 0, go to step b. + * + * The user application can transition from the _SAVING|_RUNNING + * (pre-copy state) to the _SAVING (stop-and-copy) state regardless of the + * number of pending bytes. The user application should iterate in _SAVING + * (stop-and-copy) until pending_bytes is 0. + * + * The sequence to be followed while _RESUMING device state is as follows: + * While data for this device is available, repeat the following steps: + * a. Read data_offset from where the user application should write data. + * b. Write migration data starting at the migration region + data_offset for + * the length determined by data_size from the migration source. + * c. Write data_size, which indicates to the vendor driver that data is + * written in the migration region. Vendor driver must return this write + * operations on consuming data. Vendor driver should apply the + * user-provided migration region data to the device resume state. + * + * If an error occurs during the above sequences, the vendor driver can return + * an error code for next read() or write() operation, which will terminate the + * loop. The user application should then take the next necessary action, for + * example, failing migration or terminating the user application. + * + * For the user application, data is opaque. The user application should write + * data in the same order as the data is received and the data should be of + * same transaction size at the source. + */ + +struct vfio_device_migration_info { + __u32 device_state; /* VFIO device state */ +#define VFIO_DEVICE_STATE_STOP (0) +#define VFIO_DEVICE_STATE_RUNNING (1 << 0) +#define VFIO_DEVICE_STATE_SAVING (1 << 1) +#define VFIO_DEVICE_STATE_RESUMING (1 << 2) +#define VFIO_DEVICE_STATE_MASK (VFIO_DEVICE_STATE_RUNNING | \ + VFIO_DEVICE_STATE_SAVING | \ + VFIO_DEVICE_STATE_RESUMING) + +#define VFIO_DEVICE_STATE_VALID(state) \ + (state & VFIO_DEVICE_STATE_RESUMING ? \ + (state & VFIO_DEVICE_STATE_MASK) == VFIO_DEVICE_STATE_RESUMING : 1) + +#define VFIO_DEVICE_STATE_IS_ERROR(state) \ + ((state & VFIO_DEVICE_STATE_MASK) == (VFIO_DEVICE_STATE_SAVING | \ + VFIO_DEVICE_STATE_RESUMING)) + +#define VFIO_DEVICE_STATE_SET_ERROR(state) \ + ((state & ~VFIO_DEVICE_STATE_MASK) | VFIO_DEVICE_SATE_SAVING | \ + VFIO_DEVICE_STATE_RESUMING) + + __u32 reserved; + __u64 pending_bytes; + __u64 data_offset; + __u64 data_size; +}; + /* * The MSIX mappable capability informs that MSIX data of a BAR can be mmapped * which allows direct access to non-MSIX registers which happened to be within From patchwork Mon May 4 15:58:56 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kirti Wankhede X-Patchwork-Id: 283452 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=-9.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 B0A7CC4724C for ; Mon, 4 May 2020 16:41:36 +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 6AF7E206D9 for ; Mon, 4 May 2020 16:41:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="Ldjs7jkQ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6AF7E206D9 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=nvidia.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:49000 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jVe9v-0004kh-Jc for qemu-devel@archiver.kernel.org; Mon, 04 May 2020 12:41:35 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:47478) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jVe6E-0006J0-4o for qemu-devel@nongnu.org; Mon, 04 May 2020 12:37:46 -0400 Received: from hqnvemgate24.nvidia.com ([216.228.121.143]:17309) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jVe6C-0000CH-Od for qemu-devel@nongnu.org; Mon, 04 May 2020 12:37:45 -0400 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate24.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Mon, 04 May 2020 09:30:35 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Mon, 04 May 2020 09:32:42 -0700 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Mon, 04 May 2020 09:32:42 -0700 Received: from HQMAIL101.nvidia.com (172.20.187.10) by HQMAIL111.nvidia.com (172.20.187.18) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Mon, 4 May 2020 16:32:42 +0000 Received: from kwankhede-dev.nvidia.com (10.124.1.5) by HQMAIL101.nvidia.com (172.20.187.10) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Mon, 4 May 2020 16:32:35 +0000 From: Kirti Wankhede To: , Subject: [PATCH Kernel v18 4/7] vfio iommu: Implementation of ioctl for dirty pages tracking. Date: Mon, 4 May 2020 21:28:56 +0530 Message-ID: <1588607939-26441-5-git-send-email-kwankhede@nvidia.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1588607939-26441-1-git-send-email-kwankhede@nvidia.com> References: <1588607939-26441-1-git-send-email-kwankhede@nvidia.com> X-NVConfidentiality: public MIME-Version: 1.0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1588609835; bh=RtMEdw/Zt4Iz9FJRpB/oSAZXrCq1hLZzjyqt21YqIEc=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:X-NVConfidentiality:MIME-Version: Content-Type; b=Ldjs7jkQn+iqZnHgYUkyGrbAg3fytio+rHstinIbavoYLBIsYxIgRCrAKIdLb+5Vu 30AqCBkeMIawY+XrsUJE4lpyH5wklmvVsU/6OeniupQaLUiaQmoneBfdyPWvIgjCEj cwQJUd9HwWKCw8LtLWPtOS3SMWzrstTQis7m410NPY5t0Sq0XY26XFtcqjD/jEM69N kjT50cotuvv9j+ki1ASh7Ezxc4R16Ez+Ov9Ss0efYhPPwiWLhzgFOEWm0sY2c06J6w px6edmVDyH8mNgNuMWqdcOxy01CSfTbL90oQX8bLOnoXYGxhFGkNIabI0tWDSmfZP7 baU9W0YKFUuFQ== Received-SPF: pass client-ip=216.228.121.143; envelope-from=kwankhede@nvidia.com; helo=hqnvemgate24.nvidia.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/05/04 12:32:29 X-ACL-Warn: Detected OS = Windows 7 or 8 [fuzzy] X-Spam_score_int: -70 X-Spam_score: -7.1 X-Spam_bar: ------- X-Spam_report: (-7.1 / 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_HI=-5, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN 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: Zhengxiao.zx@Alibaba-inc.com, kevin.tian@intel.com, yi.l.liu@intel.com, yan.y.zhao@intel.com, kvm@vger.kernel.org, eskultet@redhat.com, ziye.yang@intel.com, qemu-devel@nongnu.org, cohuck@redhat.com, shuangtai.tst@alibaba-inc.com, dgilbert@redhat.com, zhi.a.wang@intel.com, mlevitsk@redhat.com, pasic@linux.ibm.com, aik@ozlabs.ru, Kirti Wankhede , eauger@redhat.com, felipe@nutanix.com, jonathan.davies@nutanix.com, changpeng.liu@intel.com, Ken.Xue@amd.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" VFIO_IOMMU_DIRTY_PAGES ioctl performs three operations: - Start dirty pages tracking while migration is active - Stop dirty pages tracking. - Get dirty pages bitmap. Its user space application's responsibility to copy content of dirty pages from source to destination during migration. To prevent DoS attack, memory for bitmap is allocated per vfio_dma structure. Bitmap size is calculated considering smallest supported page size. Bitmap is allocated for all vfio_dmas when dirty logging is enabled Bitmap is populated for already pinned pages when bitmap is allocated for a vfio_dma with the smallest supported page size. Update bitmap from pinning functions when tracking is enabled. When user application queries bitmap, check if requested page size is same as page size used to populated bitmap. If it is equal, copy bitmap, but if not equal, return error. Fixed below error by changing pgsize type from uint64_t to size_t. Reported-by: kbuild test robot All errors: drivers/vfio/vfio_iommu_type1.c:197: undefined reference to `__udivdi3' drivers/vfio/vfio_iommu_type1.c:225: undefined reference to `__udivdi3' Signed-off-by: Kirti Wankhede Reviewed-by: Neo Jia --- drivers/vfio/vfio_iommu_type1.c | 266 +++++++++++++++++++++++++++++++++++++++- 1 file changed, 260 insertions(+), 6 deletions(-) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index fa735047b04d..01dcb417836f 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -71,6 +71,7 @@ struct vfio_iommu { unsigned int dma_avail; bool v2; bool nesting; + bool dirty_page_tracking; }; struct vfio_domain { @@ -91,6 +92,7 @@ struct vfio_dma { bool lock_cap; /* capable(CAP_IPC_LOCK) */ struct task_struct *task; struct rb_root pfn_list; /* Ex-user pinned pfn list */ + unsigned long *bitmap; }; struct vfio_group { @@ -125,7 +127,21 @@ struct vfio_regions { #define IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu) \ (!list_empty(&iommu->domain_list)) +#define DIRTY_BITMAP_BYTES(n) (ALIGN(n, BITS_PER_TYPE(u64)) / BITS_PER_BYTE) + +/* + * Input argument of number of bits to bitmap_set() is unsigned integer, which + * further casts to signed integer for unaligned multi-bit operation, + * __bitmap_set(). + * Then maximum bitmap size supported is 2^31 bits divided by 2^3 bits/byte, + * that is 2^28 (256 MB) which maps to 2^31 * 2^12 = 2^43 (8TB) on 4K page + * system. + */ +#define DIRTY_BITMAP_PAGES_MAX ((u64)INT_MAX) +#define DIRTY_BITMAP_SIZE_MAX DIRTY_BITMAP_BYTES(DIRTY_BITMAP_PAGES_MAX) + static int put_pfn(unsigned long pfn, int prot); +static unsigned long vfio_pgsize_bitmap(struct vfio_iommu *iommu); /* * This code handles mapping and unmapping of user data buffers @@ -175,6 +191,77 @@ static void vfio_unlink_dma(struct vfio_iommu *iommu, struct vfio_dma *old) rb_erase(&old->node, &iommu->dma_list); } + +static int vfio_dma_bitmap_alloc(struct vfio_dma *dma, size_t pgsize) +{ + uint64_t npages = dma->size / pgsize; + + if (npages > DIRTY_BITMAP_PAGES_MAX) + return -EINVAL; + + dma->bitmap = kvzalloc(DIRTY_BITMAP_BYTES(npages), GFP_KERNEL); + if (!dma->bitmap) + return -ENOMEM; + + return 0; +} + +static void vfio_dma_bitmap_free(struct vfio_dma *dma) +{ + kfree(dma->bitmap); + dma->bitmap = NULL; +} + +static void vfio_dma_populate_bitmap(struct vfio_dma *dma, size_t pgsize) +{ + struct rb_node *p; + + if (RB_EMPTY_ROOT(&dma->pfn_list)) + return; + + for (p = rb_first(&dma->pfn_list); p; p = rb_next(p)) { + struct vfio_pfn *vpfn = rb_entry(p, struct vfio_pfn, node); + + bitmap_set(dma->bitmap, (vpfn->iova - dma->iova) / pgsize, 1); + } +} + +static int vfio_dma_bitmap_alloc_all(struct vfio_iommu *iommu, size_t pgsize) +{ + struct rb_node *n = rb_first(&iommu->dma_list); + + for (; n; n = rb_next(n)) { + struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node); + int ret; + + ret = vfio_dma_bitmap_alloc(dma, pgsize); + if (ret) { + struct rb_node *p = rb_prev(n); + + for (; p; p = rb_prev(p)) { + struct vfio_dma *dma = rb_entry(n, + struct vfio_dma, node); + + vfio_dma_bitmap_free(dma); + } + return ret; + } + vfio_dma_populate_bitmap(dma, pgsize); + } + return 0; +} + +static void vfio_dma_bitmap_free_all(struct vfio_iommu *iommu) +{ + struct rb_node *n = rb_first(&iommu->dma_list); + + for (; n; n = rb_next(n)) { + struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node); + + vfio_dma_bitmap_free(dma); + } +} + /* * Helper Functions for host iova-pfn list */ @@ -567,6 +654,18 @@ static int vfio_iommu_type1_pin_pages(void *iommu_data, vfio_unpin_page_external(dma, iova, do_accounting); goto pin_unwind; } + + if (iommu->dirty_page_tracking) { + unsigned long pgshift = + __ffs(vfio_pgsize_bitmap(iommu)); + + /* + * Bitmap populated with the smallest supported page + * size + */ + bitmap_set(dma->bitmap, + (vpfn->iova - dma->iova) >> pgshift, 1); + } } ret = i; @@ -801,6 +900,7 @@ static void vfio_remove_dma(struct vfio_iommu *iommu, struct vfio_dma *dma) vfio_unmap_unpin(iommu, dma, true); vfio_unlink_dma(iommu, dma); put_task_struct(dma->task); + vfio_dma_bitmap_free(dma); kfree(dma); iommu->dma_avail++; } @@ -831,6 +931,57 @@ static unsigned long vfio_pgsize_bitmap(struct vfio_iommu *iommu) return bitmap; } +static int vfio_iova_dirty_bitmap(struct vfio_iommu *iommu, dma_addr_t iova, + size_t size, size_t pgsize, + u64 __user *bitmap) +{ + struct vfio_dma *dma; + unsigned long pgshift = __ffs(pgsize); + unsigned int npages, bitmap_size; + + dma = vfio_find_dma(iommu, iova, 1); + + if (!dma) + return -EINVAL; + + if (dma->iova != iova || dma->size != size) + return -EINVAL; + + npages = dma->size >> pgshift; + bitmap_size = DIRTY_BITMAP_BYTES(npages); + + /* mark all pages dirty if all pages are pinned and mapped. */ + if (dma->iommu_mapped) + bitmap_set(dma->bitmap, 0, npages); + + if (copy_to_user((void __user *)bitmap, dma->bitmap, bitmap_size)) + return -EFAULT; + + /* + * Re-populate bitmap to include all pinned pages which are considered + * as dirty but exclude pages which are unpinned and pages which are + * marked dirty by vfio_dma_rw() + */ + bitmap_clear(dma->bitmap, 0, npages); + vfio_dma_populate_bitmap(dma, pgsize); + return 0; +} + +static int verify_bitmap_size(uint64_t npages, uint64_t bitmap_size) +{ + uint64_t bsize; + + if (!npages || !bitmap_size || (bitmap_size > DIRTY_BITMAP_SIZE_MAX)) + return -EINVAL; + + bsize = DIRTY_BITMAP_BYTES(npages); + + if (bitmap_size < bsize) + return -EINVAL; + + return 0; +} + static int vfio_dma_do_unmap(struct vfio_iommu *iommu, struct vfio_iommu_type1_dma_unmap *unmap) { @@ -1038,16 +1189,16 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu, unsigned long vaddr = map->vaddr; size_t size = map->size; int ret = 0, prot = 0; - uint64_t mask; + size_t pgsize; struct vfio_dma *dma; /* Verify that none of our __u64 fields overflow */ if (map->size != size || map->vaddr != vaddr || map->iova != iova) return -EINVAL; - mask = ((uint64_t)1 << __ffs(vfio_pgsize_bitmap(iommu))) - 1; + pgsize = (size_t)1 << __ffs(vfio_pgsize_bitmap(iommu)); - WARN_ON(mask & PAGE_MASK); + WARN_ON((pgsize - 1) & PAGE_MASK); /* READ/WRITE from device perspective */ if (map->flags & VFIO_DMA_MAP_FLAG_WRITE) @@ -1055,7 +1206,7 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu, if (map->flags & VFIO_DMA_MAP_FLAG_READ) prot |= IOMMU_READ; - if (!prot || !size || (size | iova | vaddr) & mask) + if (!prot || !size || (size | iova | vaddr) & (pgsize - 1)) return -EINVAL; /* Don't allow IOVA or virtual address wrap */ @@ -1130,6 +1281,12 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu, else ret = vfio_pin_map_dma(iommu, dma, size); + if (!ret && iommu->dirty_page_tracking) { + ret = vfio_dma_bitmap_alloc(dma, pgsize); + if (ret) + vfio_remove_dma(iommu, dma); + } + out_unlock: mutex_unlock(&iommu->lock); return ret; @@ -2278,6 +2435,93 @@ static long vfio_iommu_type1_ioctl(void *iommu_data, return copy_to_user((void __user *)arg, &unmap, minsz) ? -EFAULT : 0; + } else if (cmd == VFIO_IOMMU_DIRTY_PAGES) { + struct vfio_iommu_type1_dirty_bitmap dirty; + uint32_t mask = VFIO_IOMMU_DIRTY_PAGES_FLAG_START | + VFIO_IOMMU_DIRTY_PAGES_FLAG_STOP | + VFIO_IOMMU_DIRTY_PAGES_FLAG_GET_BITMAP; + int ret = 0; + + if (!iommu->v2) + return -EACCES; + + minsz = offsetofend(struct vfio_iommu_type1_dirty_bitmap, + flags); + + if (copy_from_user(&dirty, (void __user *)arg, minsz)) + return -EFAULT; + + if (dirty.argsz < minsz || dirty.flags & ~mask) + return -EINVAL; + + /* only one flag should be set at a time */ + if (__ffs(dirty.flags) != __fls(dirty.flags)) + return -EINVAL; + + if (dirty.flags & VFIO_IOMMU_DIRTY_PAGES_FLAG_START) { + size_t pgsize = 1 << __ffs(vfio_pgsize_bitmap(iommu)); + + mutex_lock(&iommu->lock); + if (!iommu->dirty_page_tracking) { + ret = vfio_dma_bitmap_alloc_all(iommu, pgsize); + if (!ret) + iommu->dirty_page_tracking = true; + } + mutex_unlock(&iommu->lock); + return ret; + } else if (dirty.flags & VFIO_IOMMU_DIRTY_PAGES_FLAG_STOP) { + mutex_lock(&iommu->lock); + if (iommu->dirty_page_tracking) { + iommu->dirty_page_tracking = false; + vfio_dma_bitmap_free_all(iommu); + } + mutex_unlock(&iommu->lock); + return 0; + } else if (dirty.flags & + VFIO_IOMMU_DIRTY_PAGES_FLAG_GET_BITMAP) { + struct vfio_iommu_type1_dirty_bitmap_get range; + unsigned long pgshift; + size_t data_size = dirty.argsz - minsz; + size_t iommu_pgsize = + (size_t)1 << __ffs(vfio_pgsize_bitmap(iommu)); + + if (!data_size || data_size < sizeof(range)) + return -EINVAL; + + if (copy_from_user(&range, (void __user *)(arg + minsz), + sizeof(range))) + return -EFAULT; + + /* allow only smallest supported pgsize */ + if (range.bitmap.pgsize != iommu_pgsize) + return -EINVAL; + if (range.iova & (iommu_pgsize - 1)) + return -EINVAL; + if (!range.size || range.size & (iommu_pgsize - 1)) + return -EINVAL; + if (range.iova + range.size < range.iova) + return -EINVAL; + if (!access_ok((void __user *)range.bitmap.data, + range.bitmap.size)) + return -EINVAL; + + pgshift = __ffs(range.bitmap.pgsize); + ret = verify_bitmap_size(range.size >> pgshift, + range.bitmap.size); + if (ret) + return ret; + + mutex_lock(&iommu->lock); + if (iommu->dirty_page_tracking) + ret = vfio_iova_dirty_bitmap(iommu, range.iova, + range.size, range.bitmap.pgsize, + range.bitmap.data); + else + ret = -EINVAL; + mutex_unlock(&iommu->lock); + + return ret; + } } return -ENOTTY; @@ -2345,10 +2589,20 @@ static int vfio_iommu_type1_dma_rw_chunk(struct vfio_iommu *iommu, vaddr = dma->vaddr + offset; - if (write) + if (write) { *copied = copy_to_user((void __user *)vaddr, data, count) ? 0 : count; - else + if (*copied && iommu->dirty_page_tracking) { + unsigned long pgshift = + __ffs(vfio_pgsize_bitmap(iommu)); + /* + * Bitmap populated with the smallest supported page + * size + */ + bitmap_set(dma->bitmap, offset >> pgshift, + *copied >> pgshift); + } + } else *copied = copy_from_user(data, (void __user *)vaddr, count) ? 0 : count; if (kthread) From patchwork Mon May 4 15:58:57 2020 Content-Type: text/plain; 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For example, in pre-copy phase while guest driver could access those pages, host device or vendor driver can dirty these mapped pages. Such pages should be marked dirty so as to maintain memory consistency for a user making use of dirty page tracking. To get bitmap during unmap, user should allocate memory for bitmap, set size of allocated memory, set page size to be considered for bitmap and set flag VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP. Signed-off-by: Kirti Wankhede Reviewed-by: Neo Jia --- drivers/vfio/vfio_iommu_type1.c | 84 +++++++++++++++++++++++++++++++++++++++-- include/uapi/linux/vfio.h | 10 +++++ 2 files changed, 90 insertions(+), 4 deletions(-) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index 01dcb417836f..8b27faf1ec38 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -983,12 +983,14 @@ static int verify_bitmap_size(uint64_t npages, uint64_t bitmap_size) } static int vfio_dma_do_unmap(struct vfio_iommu *iommu, - struct vfio_iommu_type1_dma_unmap *unmap) + struct vfio_iommu_type1_dma_unmap *unmap, + struct vfio_bitmap *bitmap) { uint64_t mask; struct vfio_dma *dma, *dma_last = NULL; size_t unmapped = 0; int ret = 0, retries = 0; + unsigned long *final_bitmap = NULL, *temp_bitmap = NULL; mask = ((uint64_t)1 << __ffs(vfio_pgsize_bitmap(iommu))) - 1; @@ -1041,6 +1043,7 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, ret = -EINVAL; goto unlock; } + dma = vfio_find_dma(iommu, unmap->iova + unmap->size - 1, 0); if (dma && dma->iova + dma->size != unmap->iova + unmap->size) { ret = -EINVAL; @@ -1048,6 +1051,22 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, } } + if ((unmap->flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) && + iommu->dirty_page_tracking) { + final_bitmap = kvzalloc(bitmap->size, GFP_KERNEL); + if (!final_bitmap) { + ret = -ENOMEM; + goto unlock; + } + + temp_bitmap = kvzalloc(bitmap->size, GFP_KERNEL); + if (!temp_bitmap) { + ret = -ENOMEM; + kfree(final_bitmap); + goto unlock; + } + } + while ((dma = vfio_find_dma(iommu, unmap->iova, unmap->size))) { if (!iommu->v2 && unmap->iova > dma->iova) break; @@ -1058,6 +1077,24 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, if (dma->task->mm != current->mm) break; + if ((unmap->flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) && + iommu->dirty_page_tracking) { + unsigned long pgshift = __ffs(bitmap->pgsize); + unsigned int npages = dma->size >> pgshift; + unsigned int shift; + + vfio_iova_dirty_bitmap(iommu, dma->iova, dma->size, + bitmap->pgsize, (u64 *)temp_bitmap); + + shift = (dma->iova - unmap->iova) >> pgshift; + if (shift) + bitmap_shift_left(temp_bitmap, temp_bitmap, + shift, npages); + bitmap_or(final_bitmap, final_bitmap, temp_bitmap, + shift + npages); + memset(temp_bitmap, 0, bitmap->size); + } + if (!RB_EMPTY_ROOT(&dma->pfn_list)) { struct vfio_iommu_type1_dma_unmap nb_unmap; @@ -1088,6 +1125,16 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, } unlock: + if ((unmap->flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) && + iommu->dirty_page_tracking && final_bitmap) { + if (copy_to_user((void __user *)bitmap->data, final_bitmap, + bitmap->size)) + ret = -EFAULT; + + kfree(final_bitmap); + kfree(temp_bitmap); + } + mutex_unlock(&iommu->lock); /* Report how much was unmapped */ @@ -2419,17 +2466,46 @@ static long vfio_iommu_type1_ioctl(void *iommu_data, } else if (cmd == VFIO_IOMMU_UNMAP_DMA) { struct vfio_iommu_type1_dma_unmap unmap; - long ret; + struct vfio_bitmap bitmap = { 0 }; + int ret; minsz = offsetofend(struct vfio_iommu_type1_dma_unmap, size); if (copy_from_user(&unmap, (void __user *)arg, minsz)) return -EFAULT; - if (unmap.argsz < minsz || unmap.flags) + if (unmap.argsz < minsz || + unmap.flags & ~VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) return -EINVAL; - ret = vfio_dma_do_unmap(iommu, &unmap); + if (unmap.flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) { + unsigned long pgshift; + size_t iommu_pgsize = + (size_t)1 << __ffs(vfio_pgsize_bitmap(iommu)); + + if (unmap.argsz < (minsz + sizeof(bitmap))) + return -EINVAL; + + if (copy_from_user(&bitmap, + (void __user *)(arg + minsz), + sizeof(bitmap))) + return -EFAULT; + + /* allow only min supported pgsize */ + if (bitmap.pgsize != iommu_pgsize) + return -EINVAL; + if (!access_ok((void __user *)bitmap.data, bitmap.size)) + return -EINVAL; + + pgshift = __ffs(bitmap.pgsize); + ret = verify_bitmap_size(unmap.size >> pgshift, + bitmap.size); + if (ret) + return ret; + + } + + ret = vfio_dma_do_unmap(iommu, &unmap, &bitmap); if (ret) return ret; diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h index 5f359c63f5ef..e3cbf8b78623 100644 --- a/include/uapi/linux/vfio.h +++ b/include/uapi/linux/vfio.h @@ -1048,12 +1048,22 @@ struct vfio_bitmap { * field. No guarantee is made to the user that arbitrary unmaps of iova * or size different from those used in the original mapping call will * succeed. + * VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP should be set to get dirty bitmap + * before unmapping IO virtual addresses. When this flag is set, user must + * provide data[] as structure vfio_bitmap. User must allocate memory to get + * bitmap and must set size of allocated memory in vfio_bitmap.size field. + * A bit in bitmap represents one page of user provided page size in 'pgsize', + * consecutively starting from iova offset. Bit set indicates page at that + * offset from iova is dirty. Bitmap of pages in the range of unmapped size is + * returned in vfio_bitmap.data */ struct vfio_iommu_type1_dma_unmap { __u32 argsz; __u32 flags; +#define VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP (1 << 0) __u64 iova; /* IO virtual address */ __u64 size; /* Size of mapping (bytes) */ + __u8 data[]; }; #define VFIO_IOMMU_UNMAP_DMA _IO(VFIO_TYPE, VFIO_BASE + 14)