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path: root/drivers/vdpa/vdpa_user
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2022-08-11vduse: Support querying information of IOVA regionsXie Yongji
This introduces a new ioctl: VDUSE_IOTLB_GET_INFO to support querying some information of IOVA regions. Now it can be used to query whether the IOVA region supports userspace memory registration. Signed-off-by: Xie Yongji <xieyongji@bytedance.com> Message-Id: <20220803045523.23851-6-xieyongji@bytedance.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com>
2022-08-11vduse: Support registering userspace memory for IOVA regionsXie Yongji
Introduce two ioctls: VDUSE_IOTLB_REG_UMEM and VDUSE_IOTLB_DEREG_UMEM to support registering and de-registering userspace memory for IOVA regions. Now it only supports registering userspace memory for bounce buffer region in virtio-vdpa case. Signed-off-by: Xie Yongji <xieyongji@bytedance.com> Acked-by: Jason Wang <jasowang@redhat.com> Message-Id: <20220803045523.23851-5-xieyongji@bytedance.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-08-11vduse: Support using userspace pages as bounce bufferXie Yongji
Introduce two APIs: vduse_domain_add_user_bounce_pages() and vduse_domain_remove_user_bounce_pages() to support adding and removing userspace pages for bounce buffers. During adding and removing, the DMA data would be copied from the kernel bounce pages to the userspace bounce pages and back. Signed-off-by: Xie Yongji <xieyongji@bytedance.com> Acked-by: Jason Wang <jasowang@redhat.com> Message-Id: <20220803045523.23851-4-xieyongji@bytedance.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-08-11vduse: Use memcpy_{to,from}_page() in do_bounce()Xie Yongji
kmap_atomic() is being deprecated in favor of kmap_local_page(). The use of kmap_atomic() in do_bounce() is all thread local therefore kmap_local_page() is a sufficient replacement. Convert to kmap_local_page() but, instead of open coding it, use the helpers memcpy_to_page() and memcpy_from_page(). Signed-off-by: Xie Yongji <xieyongji@bytedance.com> Acked-by: Jason Wang <jasowang@redhat.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Message-Id: <20220803045523.23851-3-xieyongji@bytedance.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-08-11vduse: Remove unnecessary spin lock protectionXie Yongji
Now we use domain->iotlb_lock to protect two different variables: domain->bounce_maps->bounce_page and domain->iotlb. But for domain->bounce_maps->bounce_page, we actually don't need any synchronization between vduse_domain_get_bounce_page() and vduse_domain_free_bounce_pages() since vduse_domain_get_bounce_page() will only be called in page fault handler and vduse_domain_free_bounce_pages() will be called during file release. So let's remove the unnecessary spin lock protection in vduse_domain_get_bounce_page(). Then the usage of domain->iotlb_lock could be more clear: the lock will be only used to protect the domain->iotlb. Signed-off-by: Xie Yongji <xieyongji@bytedance.com> Acked-by: Jason Wang <jasowang@redhat.com> Message-Id: <20220803045523.23851-2-xieyongji@bytedance.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-06-24vduse: Tie vduse mgmtdev and its deviceParav Pandit
vduse devices are not backed by any real devices such as PCI. Hence it doesn't have any parent device linked to it. Kernel driver model in [1] suggests to avoid an empty device release callback. Hence tie the mgmtdevice object's life cycle to an allocate dummy struct device instead of static one. [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/core-api/kobject.rst?h=v5.18-rc7#n284 Signed-off-by: Parav Pandit <parav@nvidia.com> Message-Id: <20220613195223.473966-1-parav@nvidia.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Xie Yongji <xieyongji@bytedance.com> Acked-by: Jason Wang <jasowang@redhat.com>
2022-06-08vduse: Fix NULL pointer dereference on sysfs accessXie Yongji
The control device has no drvdata. So we will get a NULL pointer dereference when accessing control device's msg_timeout attribute via sysfs: [ 132.841881][ T3644] BUG: kernel NULL pointer dereference, address: 00000000000000f8 [ 132.850619][ T3644] RIP: 0010:msg_timeout_show (drivers/vdpa/vdpa_user/vduse_dev.c:1271) [ 132.869447][ T3644] dev_attr_show (drivers/base/core.c:2094) [ 132.870215][ T3644] sysfs_kf_seq_show (fs/sysfs/file.c:59) [ 132.871164][ T3644] ? device_remove_bin_file (drivers/base/core.c:2088) [ 132.872082][ T3644] kernfs_seq_show (fs/kernfs/file.c:164) [ 132.872838][ T3644] seq_read_iter (fs/seq_file.c:230) [ 132.873578][ T3644] ? __vmalloc_area_node (mm/vmalloc.c:3041) [ 132.874532][ T3644] kernfs_fop_read_iter (fs/kernfs/file.c:238) [ 132.875513][ T3644] __kernel_read (fs/read_write.c:440 (discriminator 1)) [ 132.876319][ T3644] kernel_read (fs/read_write.c:459) [ 132.877129][ T3644] kernel_read_file (fs/kernel_read_file.c:94) [ 132.877978][ T3644] kernel_read_file_from_fd (include/linux/file.h:45 fs/kernel_read_file.c:186) [ 132.879019][ T3644] __do_sys_finit_module (kernel/module.c:4207) [ 132.879930][ T3644] __ia32_sys_finit_module (kernel/module.c:4189) [ 132.880930][ T3644] do_int80_syscall_32 (arch/x86/entry/common.c:112 arch/x86/entry/common.c:132) [ 132.881847][ T3644] entry_INT80_compat (arch/x86/entry/entry_64_compat.S:419) To fix it, don't create the unneeded attribute for control device anymore. Fixes: c8a6153b6c59 ("vduse: Introduce VDUSE - vDPA Device in Userspace") Reported-by: kernel test robot <oliver.sang@intel.com> Cc: stable@vger.kernel.org Signed-off-by: Xie Yongji <xieyongji@bytedance.com> Message-Id: <20220426073656.229-1-xieyongji@bytedance.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-05-31vdpa: multiple address spaces supportGautam Dawar
This patches introduces the multiple address spaces support for vDPA device. This idea is to identify a specific address space via an dedicated identifier - ASID. During vDPA device allocation, vDPA device driver needs to report the number of address spaces supported by the device then the DMA mapping ops of the vDPA device needs to be extended to support ASID. This helps to isolate the environments for the virtqueue that will not be assigned directly. E.g in the case of virtio-net, the control virtqueue will not be assigned directly to guest. As a start, simply claim 1 virtqueue groups and 1 address spaces for all vDPA devices. And vhost-vDPA will simply reject the device with more than 1 virtqueue groups or address spaces. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Gautam Dawar <gdawar@xilinx.com> Message-Id: <20220330180436.24644-7-gdawar@xilinx.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-05-31vdpa: introduce virtqueue groupsGautam Dawar
This patch introduces virtqueue groups to vDPA device. The virtqueue group is the minimal set of virtqueues that must share an address space. And the address space identifier could only be attached to a specific virtqueue group. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Gautam Dawar <gdawar@xilinx.com> Message-Id: <20220330180436.24644-6-gdawar@xilinx.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-03-24Merge tag 'iommu-updates-v5.18' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu Pull iommu updates from Joerg Roedel: - IOMMU Core changes: - Removal of aux domain related code as it is basically dead and will be replaced by iommu-fd framework - Split of iommu_ops to carry domain-specific call-backs separatly - Cleanup to remove useless ops->capable implementations - Improve 32-bit free space estimate in iova allocator - Intel VT-d updates: - Various cleanups of the driver - Support for ATS of SoC-integrated devices listed in ACPI/SATC table - ARM SMMU updates: - Fix SMMUv3 soft lockup during continuous stream of events - Fix error path for Qualcomm SMMU probe() - Rework SMMU IRQ setup to prepare the ground for PMU support - Minor cleanups and refactoring - AMD IOMMU driver: - Some minor cleanups and error-handling fixes - Rockchip IOMMU driver: - Use standard driver registration - MSM IOMMU driver: - Minor cleanup and change to standard driver registration - Mediatek IOMMU driver: - Fixes for IOTLB flushing logic * tag 'iommu-updates-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (47 commits) iommu/amd: Improve amd_iommu_v2_exit() iommu/amd: Remove unused struct fault.devid iommu/amd: Clean up function declarations iommu/amd: Call memunmap in error path iommu/arm-smmu: Account for PMU interrupts iommu/vt-d: Enable ATS for the devices in SATC table iommu/vt-d: Remove unused function intel_svm_capable() iommu/vt-d: Add missing "__init" for rmrr_sanity_check() iommu/vt-d: Move intel_iommu_ops to header file iommu/vt-d: Fix indentation of goto labels iommu/vt-d: Remove unnecessary prototypes iommu/vt-d: Remove unnecessary includes iommu/vt-d: Remove DEFER_DEVICE_DOMAIN_INFO iommu/vt-d: Remove domain and devinfo mempool iommu/vt-d: Remove iova_cache_get/put() iommu/vt-d: Remove finding domain in dmar_insert_one_dev_info() iommu/vt-d: Remove intel_iommu::domains iommu/mediatek: Always tlb_flush_all when each PM resume iommu/mediatek: Add tlb_lock in tlb_flush_all iommu/mediatek: Remove the power status checking in tlb flush all ...
2022-03-04vduse: Fix returning wrong type in vduse_domain_alloc_iova()Xie Yongji
This fixes the following smatch warnings: drivers/vdpa/vdpa_user/iova_domain.c:305 vduse_domain_alloc_iova() warn: should 'iova_pfn << shift' be a 64 bit type? Fixes: 8c773d53fb7b ("vduse: Implement an MMU-based software IOTLB") Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Xie Yongji <xieyongji@bytedance.com> Link: https://lore.kernel.org/r/20220121083940.102-1-xieyongji@bytedance.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com>
2022-02-14iommu/iova: Separate out rcache initJohn Garry
Currently the rcache structures are allocated for all IOVA domains, even if they do not use "fast" alloc+free interface. This is wasteful of memory. In addition, fails in init_iova_rcaches() are not handled safely, which is less than ideal. Make "fast" users call a separate rcache init explicitly, which includes error checking. Signed-off-by: John Garry <john.garry@huawei.com> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Link: https://lore.kernel.org/r/1643882360-241739-1-git-send-email-john.garry@huawei.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2022-01-18Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhostLinus Torvalds
Pull virtio updates from Michael Tsirkin: "virtio,vdpa,qemu_fw_cfg: features, cleanups, and fixes. - partial support for < MAX_ORDER - 1 granularity for virtio-mem - driver_override for vdpa - sysfs ABI documentation for vdpa - multiqueue config support for mlx5 vdpa - and misc fixes, cleanups" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (42 commits) vdpa/mlx5: Fix tracking of current number of VQs vdpa/mlx5: Fix is_index_valid() to refer to features vdpa: Protect vdpa reset with cf_mutex vdpa: Avoid taking cf_mutex lock on get status vdpa/vdpa_sim_net: Report max device capabilities vdpa: Use BIT_ULL for bit operations vdpa/vdpa_sim: Configure max supported virtqueues vdpa/mlx5: Report max device capabilities vdpa: Support reporting max device capabilities vdpa/mlx5: Restore cur_num_vqs in case of failure in change_num_qps() vdpa: Add support for returning device configuration information vdpa/mlx5: Support configuring max data virtqueue vdpa/mlx5: Fix config_attr_mask assignment vdpa: Allow to configure max data virtqueues vdpa: Read device configuration only if FEATURES_OK vdpa: Sync calls set/get config/status with cf_mutex vdpa/mlx5: Distribute RX virtqueues in RQT object vdpa: Provide interface to read driver features vdpa: clean up get_config_size ret value handling virtio_ring: mark ring unused on error ...
2022-01-14vdpa: Provide interface to read driver featuresEli Cohen
Provide an interface to read the negotiated features. This is needed when building the netlink message in vdpa_dev_net_config_fill(). Also fix the implementation of vdpa_dev_net_config_fill() to use the negotiated features instead of the device features. To make APIs clearer, make the following name changes to struct vdpa_config_ops so they better describe their operations: get_features -> get_device_features set_features -> set_driver_features Finally, add get_driver_features to return the negotiated features and add implementation to all the upstream drivers. Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Eli Cohen <elic@nvidia.com> Link: https://lore.kernel.org/r/20220105114646.577224-2-elic@nvidia.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-01-14vduse: moving kvfree into callerGuanjun
This free action should be moved into caller 'vduse_ioctl' in concert with the allocation. No functional change. Signed-off-by: Guanjun <guanjun@linux.alibaba.com> Link: https://lore.kernel.org/r/1638780498-55571-1-git-send-email-guanjun@linux.alibaba.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-01-04Merge branches 'arm/smmu', 'virtio', 'x86/amd', 'x86/vt-d' and 'core' into nextJoerg Roedel
2021-12-17iommu/iova: Move fast alloc size roundup into alloc_iova_fast()John Garry via iommu
It really is a property of the IOVA rcache code that we need to alloc a power-of-2 size, so relocate the functionality to resize into alloc_iova_fast(), rather than the callsites. Signed-off-by: John Garry <john.garry@huawei.com> Acked-by: Will Deacon <will@kernel.org> Reviewed-by: Xie Yongji <xieyongji@bytedance.com> Acked-by: Jason Wang <jasowang@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Robin Murphy <robin.murphy@arm.com> Link: https://lore.kernel.org/r/1638875846-23993-1-git-send-email-john.garry@huawei.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2021-12-08vduse: check that offset is within bounds in get_config()Dan Carpenter
This condition checks "len" but it does not check "offset" and that could result in an out of bounds read if "offset > dev->config_size". The problem is that since both variables are unsigned the "dev->config_size - offset" subtraction would result in a very high unsigned value. I think these checks might not be necessary because "len" and "offset" are supposed to already have been validated using the vhost_vdpa_config_validate() function. But I do not know the code perfectly, and I like to be safe. Fixes: c8a6153b6c59 ("vduse: Introduce VDUSE - vDPA Device in Userspace") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Link: https://lore.kernel.org/r/20211208150956.GA29160@kili Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Cc: stable@vger.kernel.org
2021-12-08vduse: fix memory corruption in vduse_dev_ioctl()Dan Carpenter
The "config.offset" comes from the user. There needs to a check to prevent it being out of bounds. The "config.offset" and "dev->config_size" variables are both type u32. So if the offset if out of bounds then the "dev->config_size - config.offset" subtraction results in a very high u32 value. The out of bounds offset can result in memory corruption. Fixes: c8a6153b6c59 ("vduse: Introduce VDUSE - vDPA Device in Userspace") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Link: https://lore.kernel.org/r/20211208103307.GA3778@kili Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Cc: stable@vger.kernel.org
2021-11-01vdpa: Enable user to set mac and mtu of vdpa deviceParav Pandit
$ vdpa dev add name bar mgmtdev vdpasim_net mac 00:11:22:33:44:55 mtu 9000 $ vdpa dev config show bar: mac 00:11:22:33:44:55 link up link_announce false mtu 9000 $ vdpa dev config show -jp { "config": { "bar": { "mac": "00:11:22:33:44:55", "link ": "up", "link_announce ": false, "mtu": 9000, } } } Signed-off-by: Parav Pandit <parav@nvidia.com> Reviewed-by: Eli Cohen <elic@nvidia.com> Acked-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20211026175519.87795-5-parav@nvidia.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
2021-10-22vduse: Fix race condition between resetting and irq injectingXie Yongji
The interrupt might be triggered after a reset since there is no synchronization between resetting and irq injecting. And it might break something if the interrupt is delayed until a new round of device initialization. Fixes: c8a6153b6c59 ("vduse: Introduce VDUSE - vDPA Device in Userspace") Signed-off-by: Xie Yongji <xieyongji@bytedance.com> Link: https://lore.kernel.org/r/20210929083050.88-1-xieyongji@bytedance.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-10-22vduse: Disallow injecting interrupt before DRIVER_OK is setXie Yongji
The interrupt callback should not be triggered before DRIVER_OK is set. Otherwise, it might break the virtio device driver. So let's add a check to avoid the unexpected behavior. Fixes: c8a6153b6c59 ("vduse: Introduce VDUSE - vDPA Device in Userspace") Signed-off-by: Xie Yongji <xieyongji@bytedance.com> Link: https://lore.kernel.org/r/20210923075722.98-1-xieyongji@bytedance.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-09-14vduse: Cleanup the old kernel states after reset failureXie Yongji
We should cleanup the old kernel states e.g. interrupt callback no matter whether the userspace handle the reset correctly or not since virtio-vdpa can't handle the reset failure now. Otherwise, the old state might be used after reset which might break something, e.g. the old interrupt callback might be triggered by userspace after reset, which can break the virtio device driver. Signed-off-by: Xie Yongji <xieyongji@bytedance.com> Link: https://lore.kernel.org/r/20210906142158.181-1-xieyongji@bytedance.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com>
2021-09-14vduse: missing error code in vduse_init()Dan Carpenter
This should return -ENOMEM if alloc_workqueue() fails. Currently it returns success. Fixes: b66219796563 ("vduse: Introduce VDUSE - vDPA Device in Userspace") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Link: https://lore.kernel.org/r/20210907073223.GA18254@kili Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Xie Yongji <xieyongji@bytedance.com> Acked-by: Jason Wang <jasowang@redhat.com>
2021-09-11Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhostLinus Torvalds
Pull virtio updates from Michael Tsirkin: - vduse driver ("vDPA Device in Userspace") supporting emulated virtio block devices - virtio-vsock support for end of record with SEQPACKET - vdpa: mac and mq support for ifcvf and mlx5 - vdpa: management netlink for ifcvf - virtio-i2c, gpio dt bindings - misc fixes and cleanups * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (39 commits) Documentation: Add documentation for VDUSE vduse: Introduce VDUSE - vDPA Device in Userspace vduse: Implement an MMU-based software IOTLB vdpa: Support transferring virtual addressing during DMA mapping vdpa: factor out vhost_vdpa_pa_map() and vhost_vdpa_pa_unmap() vdpa: Add an opaque pointer for vdpa_config_ops.dma_map() vhost-iotlb: Add an opaque pointer for vhost IOTLB vhost-vdpa: Handle the failure of vdpa_reset() vdpa: Add reset callback in vdpa_config_ops vdpa: Fix some coding style issues file: Export receive_fd() to modules eventfd: Export eventfd_wake_count to modules iova: Export alloc_iova_fast() and free_iova_fast() virtio-blk: remove unneeded "likely" statements virtio-balloon: Use virtio_find_vqs() helper vdpa: Make use of PFN_PHYS/PFN_UP/PFN_DOWN helper macro vsock_test: update message bounds test for MSG_EOR af_vsock: rename variables in receive loop virtio/vsock: support MSG_EOR bit processing vhost/vsock: support MSG_EOR bit processing ...
2021-09-06Documentation: Add documentation for VDUSEXie Yongji
VDUSE (vDPA Device in Userspace) is a framework to support implementing software-emulated vDPA devices in userspace. This document is intended to clarify the VDUSE design and usage. Signed-off-by: Xie Yongji <xieyongji@bytedance.com> Acked-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20210831103634.33-14-xieyongji@bytedance.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-09-06vduse: Introduce VDUSE - vDPA Device in UserspaceXie Yongji
This VDUSE driver enables implementing software-emulated vDPA devices in userspace. The vDPA device is created by ioctl(VDUSE_CREATE_DEV) on /dev/vduse/control. Then a char device interface (/dev/vduse/$NAME) is exported to userspace for device emulation. In order to make the device emulation more secure, the device's control path is handled in kernel. A message mechnism is introduced to forward some dataplane related control messages to userspace. And in the data path, the DMA buffer will be mapped into userspace address space through different ways depending on the vDPA bus to which the vDPA device is attached. In virtio-vdpa case, the MMU-based software IOTLB is used to achieve that. And in vhost-vdpa case, the DMA buffer is reside in a userspace memory region which can be shared to the VDUSE userspace processs via transferring the shmfd. For more details on VDUSE design and usage, please see the follow-on Documentation commit. NB(mst): when merging this with b542e383d8c0 ("eventfd: Make signal recursion protection a task bit") replace eventfd_signal_count with eventfd_signal_allowed, and drop the previous ("eventfd: Export eventfd_wake_count to modules"). Signed-off-by: Xie Yongji <xieyongji@bytedance.com> Acked-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20210831103634.33-13-xieyongji@bytedance.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-09-06vduse: Implement an MMU-based software IOTLBXie Yongji
This implements an MMU-based software IOTLB to support mapping kernel dma buffer into userspace dynamically. The basic idea behind it is treating MMU (VA->PA) as IOMMU (IOVA->PA). The software IOTLB will set up MMU mapping instead of IOMMU mapping for the DMA transfer so that the userspace process is able to use its virtual address to access the dma buffer in kernel. To avoid security issue, a bounce-buffering mechanism is introduced to prevent userspace accessing the original buffer directly which may contain other kernel data. During the mapping, unmapping, the software IOTLB will copy the data from the original buffer to the bounce buffer and back, depending on the direction of the transfer. And the bounce-buffer addresses will be mapped into the user address space instead of the original one. Signed-off-by: Xie Yongji <xieyongji@bytedance.com> Acked-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20210831103634.33-12-xieyongji@bytedance.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>