On Sat, Jun 14, 2025 at 12:14:49AM -0700, Nicolin Chen wrote:
I made some small changes:
/**
- struct tegra241_vintf - Virtual Interface
- @vsmmu: Embedded arm_vsmmu structure
- @idx: Global index in the CMDQV
- @enabled: Enable status
- @hyp_own: Owned by hypervisor (in-kernel)
- @cmdqv: Parent CMDQV pointer
- @lvcmdqs: List of logical VCMDQ pointers
Added: + * @lvcmdq_mutex: Lock to serialize user-allocated lvcmdq
for the following change:
@@ -154,19 +172,41 @@ struct tegra241_vintf { struct tegra241_cmdqv *cmdqv; struct tegra241_vcmdq **lvcmdqs;
- struct mutex lvcmdq_mutex; /* user space race */
[...]
+static void +tegra241_vintf_destroy_lvcmdq_user(struct iommufd_hw_queue *hw_queue) +{
- struct tegra241_vcmdq *vcmdq = hw_queue_to_vcmdq(hw_queue);
- tegra241_vcmdq_hw_deinit(vcmdq);
- tegra241_vcmdq_unmap_lvcmdq(vcmdq);
- tegra241_vintf_free_lvcmdq(vcmdq->vintf, vcmdq->lidx);
- if (vcmdq->prev)
iommufd_hw_queue_undepend(vcmdq, vcmdq->prev, core);
Added mutex to pair with tegra241_vintf_alloc_lvcmdq_user():
mutex_lock(&vcmdq->vintf->lvcmdq_mutex); ... mutex_unlock(&vcmdq->vintf->lvcmdq_mutex);
- /*
* Initialize the user-owned VINTF without a LVCMDQ, because it has to* wait for the allocation of a user-owned LVCMDQ, for security reason.* It is different than the kernel-owned VINTF0, which had pre-assigned* and pre-allocated global VCMDQs that would be mapped to the LVCMDQs* by the tegra241_vintf_hw_init() call.*/- ret = tegra241_vintf_hw_init(vintf, false);
Revised a bit: + /* + * Initialize the user-owned VINTF without a LVCMDQ, as it cannot pre- + * allocate a LVCMDQ until user space wants one, for security reasons. [...]
Thanks Nicolin