Hi all: This series introduce basic functionality of doorbell mapping support for vhost-vDPA. Userspace program may use mmap() to map a the doorbell of a specific virtqueue into its address space. This is help to reudce the syscall or vmexit overhead. A new vdpa_config_ops was introduced to report the location of the doorbell, vhost_vdpa may then choose to map the doorbell when: - The doorbell register is localted at page boundary - The doorbell register does not share page with non doorbell registers. With these two requriements, doorbells layout could be modelled more easily from guest (e.g Qemu's page-per-vq model) and it would be more safe to avoid exposing other registers to userspace directly. IFCVF was reported to support this feature but unfortuantely the one I used does not meet those requirements. So a new virtio-pci driver for vDPA bus is introduced, and I verify this with page-per-vq=on with a userspace vhost-vdpa driver in guest. Please review. Thanks Jason Wang (6): vhost: allow device that does not depend on vhost worker vhost: use mmgrab() instead of mmget() for non worker device vdpa: introduce get_vq_notification method vhost_vdpa: support doorbell mapping via mmap vdpa: introduce virtio pci driver vdpa: vp_vdpa: report doorbell location drivers/vdpa/Kconfig | 6 + drivers/vdpa/Makefile | 1 + drivers/vdpa/vp_vdpa/Makefile | 2 + drivers/vdpa/vp_vdpa/vp_vdpa.c | 604 +++++++++++++++++++++++++++++++++ drivers/vhost/net.c | 2 +- drivers/vhost/scsi.c | 2 +- drivers/vhost/vdpa.c | 61 +++- drivers/vhost/vhost.c | 80 +++-- drivers/vhost/vhost.h | 2 + drivers/vhost/vsock.c | 2 +- include/linux/vdpa.h | 16 + 11 files changed, 753 insertions(+), 25 deletions(-) create mode 100644 drivers/vdpa/vp_vdpa/Makefile create mode 100644 drivers/vdpa/vp_vdpa/vp_vdpa.c -- 2.20.1
