From: "Tian, Kevin" <kevin.tian@intel.com>
To: Nicolin Chen <nicolinc@nvidia.com>,
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Subject: RE: [PATCH v6 05/14] iommufd: Add IOMMUFD_OBJ_VEVENTQ and IOMMUFD_CMD_VEVENTQ_ALLOC
Date: Tue, 18 Feb 2025 05:13:47 +0000 [thread overview]
Message-ID: <BN9PR11MB527614EB9CBA3BAB951B0DDD8CFA2@BN9PR11MB5276.namprd11.prod.outlook.com> (raw)
In-Reply-To: <2fb8d9c7b01ad36b42849283cd33d931f11092cb.1737754129.git.nicolinc@nvidia.com>
> From: Nicolin Chen <nicolinc@nvidia.com>
> Sent: Saturday, January 25, 2025 8:31 AM
> +
> +/*
> + * An iommufd_veventq object represents an interface to deliver vIOMMU
> events to
> + * the user space. It is created/destroyed by the user space and associated
> with
> + * vIOMMU object(s) during the allocations.
s/object(s)/object/, given the eventq cannot be shared between vIOMMUs.
> +static inline void iommufd_vevent_handler(struct iommufd_veventq
> *veventq,
> + struct iommufd_vevent *vevent)
> +{
> + struct iommufd_eventq *eventq = &veventq->common;
> +
> + /*
> + * Remove the overflow node and add the new node at the same
> time. Note
> + * it is possible that vevent == &veventq->overflow for sequence
> update
> + */
> + spin_lock(&eventq->lock);
> + if (veventq->overflow.on_list) {
> + list_del(&veventq->overflow.node);
> + veventq->overflow.on_list = false;
> + }
We can save one field 'on_list' in every entry by:
if (list_is_last(&veventq->overflow.node, &eventq->deliver))
list_del(&veventq->overflow.node);
> +
> +/**
> + * struct iommufd_vevent_header - Virtual Event Header for a vEVENTQ
> Status
> + * @flags: Combination of enum iommu_veventq_flag
> + * @sequence: The sequence index of a vEVENT in the vEVENTQ, with a
> range of
> + * [0, INT_MAX] where the following index of INT_MAX is 0
> + * @__reserved: Must be 0
> + *
> + * Each iommufd_vevent_header reports a sequence index of the following
> vEVENT:
> + * ---------------------------------------------------------------------------
> + * || header0 {sequence=0} | data0 | header1 {sequence=1} | data1 |...|
> dataN ||
> + * ---------------------------------------------------------------------------
> + * And this sequence index is expected to be monotonic to the sequence
> index of
> + * the previous vEVENT. If two adjacent sequence indexes has a delta larger
> than
> + * 1, it indicates that an overflow occurred to the vEVENTQ and that delta - 1
> + * number of vEVENTs lost due to the overflow (e.g. two lost vEVENTs):
> + * ---------------------------------------------------------------------------
> + * || ... | header3 {sequence=3} | data3 | header6 {sequence=6} | data6 | ...
> ||
> + * ---------------------------------------------------------------------------
> + * If an overflow occurred to the tail of the vEVENTQ and there is no
> following
> + * vEVENT providing the next sequence index, a special overflow header
> would be
> + * added to the tail of the vEVENTQ, where there would be no more type-
> specific
> + * data following the vEVENTQ:
> + * ---------------------------------------------------------------------------
> + * ||...| header3 {sequence=3} | data4 | header4 {flags=OVERFLOW,
> sequence=4} ||
> + * ---------------------------------------------------------------------------
> + */
> +struct iommufd_vevent_header {
> + __aligned_u64 flags;
> + __u32 sequence;
> + __u32 __reserved;
> +};
Is there a reason that flags must be u64? At a glance all flags fields
(except the one in iommu_hwpt_vtd_s1) in iommufd uAPIs are u32
which can cut the size of the header by half...
> +void iommufd_veventq_abort(struct iommufd_object *obj)
> +{
> + struct iommufd_eventq *eventq =
> + container_of(obj, struct iommufd_eventq, obj);
> + struct iommufd_veventq *veventq = eventq_to_veventq(eventq);
> + struct iommufd_viommu *viommu = veventq->viommu;
> + struct iommufd_vevent *cur, *next;
> +
> + lockdep_assert_held_write(&viommu->veventqs_rwsem);
> +
> + list_for_each_entry_safe(cur, next, &eventq->deliver, node) {
> + list_del(&cur->node);
> + kfree(cur);
kfree() doesn't apply to the overflow node.
otherwise it looks good to me:
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
next prev parent reply other threads:[~2025-02-18 5:14 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-01-25 0:30 [PATCH v6 00/14] iommufd: Add vIOMMU infrastructure (Part-3: vEVENTQ) Nicolin Chen
2025-01-25 0:30 ` [PATCH v6 01/14] iommufd/fault: Move two fault functions out of the header Nicolin Chen
2025-02-14 20:15 ` Jason Gunthorpe
2025-02-18 5:05 ` Tian, Kevin
2025-01-25 0:30 ` [PATCH v6 02/14] iommufd/fault: Add an iommufd_fault_init() helper Nicolin Chen
2025-01-25 0:30 ` [PATCH v6 03/14] iommufd: Abstract an iommufd_eventq from iommufd_fault Nicolin Chen
2025-02-14 20:23 ` Jason Gunthorpe
2025-01-25 0:30 ` [PATCH v6 04/14] iommufd: Rename fault.c to eventq.c Nicolin Chen
2025-01-25 0:30 ` [PATCH v6 05/14] iommufd: Add IOMMUFD_OBJ_VEVENTQ and IOMMUFD_CMD_VEVENTQ_ALLOC Nicolin Chen
2025-02-18 5:13 ` Tian, Kevin [this message]
2025-02-18 17:53 ` Nicolin Chen
2025-02-18 15:29 ` Jason Gunthorpe
2025-02-18 17:47 ` Nicolin Chen
2025-02-18 18:08 ` Jason Gunthorpe
2025-02-18 18:15 ` Nicolin Chen
2025-01-25 0:30 ` [PATCH v6 06/14] iommufd/viommu: Add iommufd_viommu_get_vdev_id helper Nicolin Chen
2025-02-18 15:31 ` Jason Gunthorpe
2025-02-20 5:17 ` Nicolin Chen
2025-02-20 16:19 ` Jason Gunthorpe
2025-01-25 0:30 ` [PATCH v6 07/14] iommufd/viommu: Add iommufd_viommu_report_event helper Nicolin Chen
2025-02-18 5:14 ` Tian, Kevin
2025-02-18 15:35 ` Jason Gunthorpe
2025-02-19 6:58 ` Tian, Kevin
2025-02-20 21:16 ` Nicolin Chen
2025-02-21 4:27 ` Tian, Kevin
2025-02-21 13:39 ` Jason Gunthorpe
2025-01-25 0:30 ` [PATCH v6 08/14] iommufd/selftest: Require vdev_id when attaching to a nested domain Nicolin Chen
2025-02-18 5:15 ` Tian, Kevin
2025-01-25 0:30 ` [PATCH v6 09/14] iommufd/selftest: Add IOMMU_TEST_OP_TRIGGER_VEVENT for vEVENTQ coverage Nicolin Chen
2025-02-18 5:16 ` Tian, Kevin
2025-01-25 0:30 ` [PATCH v6 10/14] iommufd/selftest: Add IOMMU_VEVENTQ_ALLOC test coverage Nicolin Chen
2025-02-18 5:19 ` Tian, Kevin
2025-01-25 0:30 ` [PATCH v6 11/14] Documentation: userspace-api: iommufd: Update FAULT and VEVENTQ Nicolin Chen
2025-01-28 8:21 ` Bagas Sanjaya
2025-02-18 17:02 ` Jason Gunthorpe
2025-01-25 0:30 ` [PATCH v6 12/14] iommu/arm-smmu-v3: Introduce struct arm_smmu_vmaster Nicolin Chen
2025-02-18 17:08 ` Jason Gunthorpe
2025-02-20 7:16 ` Nicolin Chen
2025-01-25 0:30 ` [PATCH v6 13/14] iommu/arm-smmu-v3: Report events that belong to devices attached to vIOMMU Nicolin Chen
2025-02-18 5:21 ` Tian, Kevin
2025-02-18 17:18 ` Jason Gunthorpe
2025-02-18 18:28 ` Nicolin Chen
2025-02-18 18:50 ` Jason Gunthorpe
2025-02-18 19:02 ` Nicolin Chen
2025-02-18 19:08 ` Jason Gunthorpe
2025-02-18 19:27 ` Nicolin Chen
2025-02-20 20:45 ` Nicolin Chen
2025-02-20 23:24 ` Jason Gunthorpe
2025-02-21 8:10 ` Nicolin Chen
2025-01-25 0:30 ` [PATCH v6 14/14] iommu/arm-smmu-v3: Set MEV bit in nested STE for DoS mitigations Nicolin Chen
2025-02-18 5:24 ` Tian, Kevin
2025-02-18 18:17 ` Pranjal Shrivastava
2025-02-18 18:52 ` Jason Gunthorpe
2025-02-20 7:12 ` Nicolin Chen
2025-02-18 18:53 ` Nicolin Chen
2025-02-20 16:15 ` Pranjal Shrivastava
2025-02-18 17:21 ` Jason Gunthorpe
2025-02-18 18:14 ` Nicolin Chen
2025-02-20 9:09 ` Nicolin Chen
2025-02-14 8:03 ` [PATCH v6 00/14] iommufd: Add vIOMMU infrastructure (Part-3: vEVENTQ) Nicolin Chen
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