On Tue, Aug 3, 2021 at 3:30 PM Jason Wang <jasowang@xxxxxxxxxx> wrote: > > > 在 2021/7/29 下午3:35, Xie Yongji 写道: > > 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. > > > > Signed-off-by: Xie Yongji <xieyongji@xxxxxxxxxxxxx> > > --- > > Documentation/userspace-api/ioctl/ioctl-number.rst | 1 + > > drivers/vdpa/Kconfig | 10 + > > drivers/vdpa/Makefile | 1 + > > drivers/vdpa/vdpa_user/Makefile | 5 + > > drivers/vdpa/vdpa_user/vduse_dev.c | 1541 ++++++++++++++++++++ > > include/uapi/linux/vduse.h | 220 +++ > > 6 files changed, 1778 insertions(+) > > create mode 100644 drivers/vdpa/vdpa_user/Makefile > > create mode 100644 drivers/vdpa/vdpa_user/vduse_dev.c > > create mode 100644 include/uapi/linux/vduse.h > > > > diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst > > index 1409e40e6345..293ca3aef358 100644 > > --- a/Documentation/userspace-api/ioctl/ioctl-number.rst > > +++ b/Documentation/userspace-api/ioctl/ioctl-number.rst > > @@ -300,6 +300,7 @@ Code Seq# Include File Comments > > 'z' 10-4F drivers/s390/crypto/zcrypt_api.h conflict! > > '|' 00-7F linux/media.h > > 0x80 00-1F linux/fb.h > > +0x81 00-1F linux/vduse.h > > 0x89 00-06 arch/x86/include/asm/sockios.h > > 0x89 0B-DF linux/sockios.h > > 0x89 E0-EF linux/sockios.h SIOCPROTOPRIVATE range > > diff --git a/drivers/vdpa/Kconfig b/drivers/vdpa/Kconfig > > index a503c1b2bfd9..6e23bce6433a 100644 > > --- a/drivers/vdpa/Kconfig > > +++ b/drivers/vdpa/Kconfig > > @@ -33,6 +33,16 @@ config VDPA_SIM_BLOCK > > vDPA block device simulator which terminates IO request in a > > memory buffer. > > > > +config VDPA_USER > > + tristate "VDUSE (vDPA Device in Userspace) support" > > + depends on EVENTFD && MMU && HAS_DMA > > + select DMA_OPS > > + select VHOST_IOTLB > > + select IOMMU_IOVA > > + help > > + With VDUSE it is possible to emulate a vDPA Device > > + in a userspace program. > > + > > config IFCVF > > tristate "Intel IFC VF vDPA driver" > > depends on PCI_MSI > > diff --git a/drivers/vdpa/Makefile b/drivers/vdpa/Makefile > > index 67fe7f3d6943..f02ebed33f19 100644 > > --- a/drivers/vdpa/Makefile > > +++ b/drivers/vdpa/Makefile > > @@ -1,6 +1,7 @@ > > # SPDX-License-Identifier: GPL-2.0 > > obj-$(CONFIG_VDPA) += vdpa.o > > obj-$(CONFIG_VDPA_SIM) += vdpa_sim/ > > +obj-$(CONFIG_VDPA_USER) += vdpa_user/ > > obj-$(CONFIG_IFCVF) += ifcvf/ > > obj-$(CONFIG_MLX5_VDPA) += mlx5/ > > obj-$(CONFIG_VP_VDPA) += virtio_pci/ > > diff --git a/drivers/vdpa/vdpa_user/Makefile b/drivers/vdpa/vdpa_user/Makefile > > new file mode 100644 > > index 000000000000..260e0b26af99 > > --- /dev/null > > +++ b/drivers/vdpa/vdpa_user/Makefile > > @@ -0,0 +1,5 @@ > > +# SPDX-License-Identifier: GPL-2.0 > > + > > +vduse-y := vduse_dev.o iova_domain.o > > + > > +obj-$(CONFIG_VDPA_USER) += vduse.o > > diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c > > new file mode 100644 > > index 000000000000..6addc62e7de6 > > --- /dev/null > > +++ b/drivers/vdpa/vdpa_user/vduse_dev.c > > @@ -0,0 +1,1541 @@ > > +// SPDX-License-Identifier: GPL-2.0-only > > +/* > > + * VDUSE: vDPA Device in Userspace > > + * > > + * Copyright (C) 2020-2021 Bytedance Inc. and/or its affiliates. All rights reserved. > > + * > > + * Author: Xie Yongji <xieyongji@xxxxxxxxxxxxx> > > + * > > + */ > > + > > +#include <linux/init.h> > > +#include <linux/module.h> > > +#include <linux/cdev.h> > > +#include <linux/device.h> > > +#include <linux/eventfd.h> > > +#include <linux/slab.h> > > +#include <linux/wait.h> > > +#include <linux/dma-map-ops.h> > > +#include <linux/poll.h> > > +#include <linux/file.h> > > +#include <linux/uio.h> > > +#include <linux/vdpa.h> > > +#include <linux/nospec.h> > > +#include <uapi/linux/vduse.h> > > +#include <uapi/linux/vdpa.h> > > +#include <uapi/linux/virtio_config.h> > > +#include <uapi/linux/virtio_ids.h> > > +#include <uapi/linux/virtio_blk.h> > > +#include <linux/mod_devicetable.h> > > + > > +#include "iova_domain.h" > > + > > +#define DRV_AUTHOR "Yongji Xie <xieyongji@xxxxxxxxxxxxx>" > > +#define DRV_DESC "vDPA Device in Userspace" > > +#define DRV_LICENSE "GPL v2" > > + > > +#define VDUSE_DEV_MAX (1U << MINORBITS) > > +#define VDUSE_BOUNCE_SIZE (64 * 1024 * 1024) > > +#define VDUSE_IOVA_SIZE (128 * 1024 * 1024) > > +#define VDUSE_REQUEST_TIMEOUT 30 > > > I think we need make this as a module parameter. 0 probably means we > need to wait for ever. > > This can help in the case when the userspace is attached by GDB. If > Michael is still not happy, we can find other solution (e.g only offload > the datapath). > OK, a device attribute might be better. Thanks, Yongji
