From 36871fb92b70599e6755d92ebdfcba7baa3d4f85 Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Thu, 19 Jan 2023 14:15:25 +0800 Subject: [PATCH] vdpa: mlx5: support per virtqueue dma device This patch implements per virtqueue dma device for mlx5_vdpa. This is needed for virtio_vdpa to work for CVQ which is backed by vringh but not DMA. We simply advertise the vDPA device itself as the DMA device for CVQ then DMA API can simply use PA so the identical mapping for CVQ can still be used. Otherwise the identical (1:1) mapping won't work when platform IOMMU is enabled since the IOVA is allocated on demand which is not necessarily the PA. This fixes the following crash when mlx5 vDPA device is bound to virtio-vdpa with platform IOMMU enabled but not in passthrough mode: BUG: unable to handle page fault for address: ff2fb3063deb1002 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 1393001067 P4D 1393002067 PUD 0 Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 55 PID: 8923 Comm: kworker/u112:3 Kdump: loaded Not tainted 6.1.0+ #7 Hardware name: Dell Inc. PowerEdge R750/0PJ80M, BIOS 1.5.4 12/17/2021 Workqueue: mlx5_vdpa_wq mlx5_cvq_kick_handler [mlx5_vdpa] RIP: 0010:vringh_getdesc_iotlb+0x93/0x1d0 [vringh] Code: 14 25 40 ef 01 00 83 82 c0 0a 00 00 01 48 2b 05 93 5a 1b ea 8b 4c 24 14 48 c1 f8 06 48 c1 e0 0c 48 03 05 90 5a 1b ea 48 01 c8 <0f> b7 00 83 aa c0 0a 00 00 01 65 ff 0d bc e4 41 3f 0f 84 05 01 00 RSP: 0018:ff46821ba664fdf8 EFLAGS: 00010282 RAX: ff2fb3063deb1002 RBX: 0000000000000a20 RCX: 0000000000000002 RDX: ff2fb318d2f94380 RSI: 0000000000000002 RDI: 0000000000000001 RBP: ff2fb3065e832410 R08: ff46821ba664fe00 R09: 0000000000000001 R10: 0000000000000000 R11: 000000000000000d R12: ff2fb3065e832488 R13: ff2fb3065e8324a8 R14: ff2fb3065e8324c8 R15: ff2fb3065e8324a8 FS: 0000000000000000(0000) GS:ff2fb3257fac0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ff2fb3063deb1002 CR3: 0000001392010006 CR4: 0000000000771ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: mlx5_cvq_kick_handler+0x89/0x2b0 [mlx5_vdpa] process_one_work+0x1e2/0x3b0 ? rescuer_thread+0x390/0x390 worker_thread+0x50/0x3a0 ? rescuer_thread+0x390/0x390 kthread+0xd6/0x100 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork+0x1f/0x30 Reviewed-by: Eli Cohen Tested-by: Eli Cohen Signed-off-by: Jason Wang Message-Id: <20230119061525.75068-6-jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin --- drivers/vdpa/mlx5/net/mlx5_vnet.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c index 75f8006856775..8f06026517b82 100644 --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c @@ -2681,6 +2681,16 @@ static int mlx5_vdpa_set_map(struct vdpa_device *vdev, unsigned int asid, return err; } +static struct device *mlx5_get_vq_dma_dev(struct vdpa_device *vdev, u16 idx) +{ + struct mlx5_vdpa_dev *mvdev = to_mvdev(vdev); + + if (is_ctrl_vq_idx(mvdev, idx)) + return &vdev->dev; + + return mvdev->vdev.dma_dev; +} + static void mlx5_vdpa_free(struct vdpa_device *vdev) { struct mlx5_vdpa_dev *mvdev = to_mvdev(vdev); @@ -2896,6 +2906,7 @@ static const struct vdpa_config_ops mlx5_vdpa_ops = { .get_generation = mlx5_vdpa_get_generation, .set_map = mlx5_vdpa_set_map, .set_group_asid = mlx5_set_group_asid, + .get_vq_dma_dev = mlx5_get_vq_dma_dev, .free = mlx5_vdpa_free, .suspend = mlx5_vdpa_suspend, };