From c471ad0e9bd46ca5f5c9c796e727230e043a091d Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Wed, 11 Jan 2017 12:32:12 +0800 Subject: vhost_net: device IOTLB support This patches implements Device IOTLB support for vhost kernel. This is done through: 1) switch to use dma helpers when map/unmap vrings from vhost codes 2) introduce a set of VhostOps to: - setting up device IOTLB request callback - processing device IOTLB request - processing device IOTLB invalidation 2) kernel support for Device IOTLB API: - allow vhost-net to query the IOMMU IOTLB entry through eventfd - enable the ability for qemu to update a specified mapping of vhost - through ioctl. - enable the ability to invalidate a specified range of iova for the device IOTLB of vhost through ioctl. In x86/intel_iommu case this is triggered through iommu memory region notifier from device IOTLB invalidation descriptor processing routine. With all the above, kernel vhost_net can co-operate with userspace IOMMU. For vhost-user, the support could be easily done on top by implementing the VhostOps. Cc: Michael S. Tsirkin Signed-off-by: Jason Wang Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/virtio/vhost-backend.c | 99 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 99 insertions(+) (limited to 'hw/virtio/vhost-backend.c') diff --git a/hw/virtio/vhost-backend.c b/hw/virtio/vhost-backend.c index 272a5ec584..be927b891e 100644 --- a/hw/virtio/vhost-backend.c +++ b/hw/virtio/vhost-backend.c @@ -185,6 +185,102 @@ static int vhost_kernel_vsock_set_running(struct vhost_dev *dev, int start) } #endif /* CONFIG_VHOST_VSOCK */ +static void vhost_kernel_iotlb_read(void *opaque) +{ + struct vhost_dev *dev = opaque; + struct vhost_msg msg; + ssize_t len; + + while ((len = read((uintptr_t)dev->opaque, &msg, sizeof msg)) > 0) { + struct vhost_iotlb_msg *imsg = &msg.iotlb; + if (len < sizeof msg) { + error_report("Wrong vhost message len: %d", (int)len); + break; + } + if (msg.type != VHOST_IOTLB_MSG) { + error_report("Unknown vhost iotlb message type"); + break; + } + switch (imsg->type) { + case VHOST_IOTLB_MISS: + vhost_device_iotlb_miss(dev, imsg->iova, + imsg->perm != VHOST_ACCESS_RO); + break; + case VHOST_IOTLB_UPDATE: + case VHOST_IOTLB_INVALIDATE: + error_report("Unexpected IOTLB message type"); + break; + case VHOST_IOTLB_ACCESS_FAIL: + /* FIXME: report device iotlb error */ + break; + default: + break; + } + } +} + +static int vhost_kernel_update_device_iotlb(struct vhost_dev *dev, + uint64_t iova, uint64_t uaddr, + uint64_t len, + IOMMUAccessFlags perm) +{ + struct vhost_msg msg; + msg.type = VHOST_IOTLB_MSG; + msg.iotlb.iova = iova; + msg.iotlb.uaddr = uaddr; + msg.iotlb.size = len; + msg.iotlb.type = VHOST_IOTLB_UPDATE; + + switch (perm) { + case IOMMU_RO: + msg.iotlb.perm = VHOST_ACCESS_RO; + break; + case IOMMU_WO: + msg.iotlb.perm = VHOST_ACCESS_WO; + break; + case IOMMU_RW: + msg.iotlb.perm = VHOST_ACCESS_RW; + break; + default: + g_assert_not_reached(); + } + + if (write((uintptr_t)dev->opaque, &msg, sizeof msg) != sizeof msg) { + error_report("Fail to update device iotlb"); + return -EFAULT; + } + + return 0; +} + +static int vhost_kernel_invalidate_device_iotlb(struct vhost_dev *dev, + uint64_t iova, uint64_t len) +{ + struct vhost_msg msg; + + msg.type = VHOST_IOTLB_MSG; + msg.iotlb.iova = iova; + msg.iotlb.size = len; + msg.iotlb.type = VHOST_IOTLB_INVALIDATE; + + if (write((uintptr_t)dev->opaque, &msg, sizeof msg) != sizeof msg) { + error_report("Fail to invalidate device iotlb"); + return -EFAULT; + } + + return 0; +} + +static void vhost_kernel_set_iotlb_callback(struct vhost_dev *dev, + int enabled) +{ + if (enabled) + qemu_set_fd_handler((uintptr_t)dev->opaque, + vhost_kernel_iotlb_read, NULL, dev); + else + qemu_set_fd_handler((uintptr_t)dev->opaque, NULL, NULL, NULL); +} + static const VhostOps kernel_ops = { .backend_type = VHOST_BACKEND_TYPE_KERNEL, .vhost_backend_init = vhost_kernel_init, @@ -214,6 +310,9 @@ static const VhostOps kernel_ops = { .vhost_vsock_set_guest_cid = vhost_kernel_vsock_set_guest_cid, .vhost_vsock_set_running = vhost_kernel_vsock_set_running, #endif /* CONFIG_VHOST_VSOCK */ + .vhost_set_iotlb_callback = vhost_kernel_set_iotlb_callback, + .vhost_update_device_iotlb = vhost_kernel_update_device_iotlb, + .vhost_invalidate_device_iotlb = vhost_kernel_invalidate_device_iotlb, }; int vhost_set_backend_type(struct vhost_dev *dev, VhostBackendType backend_type) -- cgit v1.2.3