Hi Michal,
On Tue, Aug 29, 2023 at 10:05:55AM +0200, Michal Orzel wrote:
>
>
> On 25/08/2023 10:02, Vikram Garhwal wrote:
> > Rename iommu_dt_device_is_assigned() to
> > iommu_dt_device_is_assigned_locked().
> >
> > Moving spin_lock to caller was done to prevent the concurrent access to
> > iommu_dt_device_is_assigned while doing add/remove/assign/deassign.
> > Follow-up
> > patches in this series introduces node add/remove feature.
> >
> > Signed-off-by: Vikram Garhwal <vikram.garh...@amd.com>
> >
> > ---
> > Changes from v9:
> > Make iommu_dt_device_is_assigned_locked() static and delete header.
> > Move dtdevs_lock before iommu_dt_device_is_assigned_locked().
> > Changes from v7:
> > Update commit message.
> > Add ASSERT().
> > ---
> > ---
> > xen/drivers/passthrough/device_tree.c | 16 ++++++++++++----
> > 1 file changed, 12 insertions(+), 4 deletions(-)
> >
> > diff --git a/xen/drivers/passthrough/device_tree.c
> > b/xen/drivers/passthrough/device_tree.c
> > index 1c32d7b50c..5d84c07b50 100644
> > --- a/xen/drivers/passthrough/device_tree.c
> > +++ b/xen/drivers/passthrough/device_tree.c
> > @@ -83,16 +83,17 @@ fail:
> > return rc;
> > }
> >
> > -static bool_t iommu_dt_device_is_assigned(const struct dt_device_node *dev)
> > +static bool_t
> > +iommu_dt_device_is_assigned_locked(const struct dt_device_node *dev)
> This does not apply cleanly due to recent change from bool_t to bool. Please
> rebase for v11 (the function
> should then fit in a single line I think).
Fixed the changes here and made it one-line.
>
> > {
> > bool_t assigned = 0;
> >
> > + ASSERT(spin_is_locked(&dtdevs_lock));
> > +
> > if ( !dt_device_is_protected(dev) )
> > return 0;
> >
> > - spin_lock(&dtdevs_lock);
> > assigned = !list_empty(&dev->domain_list);
> > - spin_unlock(&dtdevs_lock);
> >
> > return assigned;
> > }
> > @@ -223,17 +224,24 @@ int iommu_do_dt_domctl(struct xen_domctl *domctl,
> > struct domain *d,
> > if ( ret )
> > break;
> >
> > + spin_lock(&dtdevs_lock);
> Why is this lock placed here instead of ...
> > +
> > if ( domctl->cmd == XEN_DOMCTL_test_assign_device )
> > {
> > - if ( iommu_dt_device_is_assigned(dev) )
> > +
> ... here, right before iommu_dt_device_is_assigned_locked()?
Moved the lock before iommu_dt_device_is_assigned_locked().
> > + if ( iommu_dt_device_is_assigned_locked(dev) )
> > {
> > printk(XENLOG_G_ERR "%s already assigned.\n",
> > dt_node_full_name(dev));
> > ret = -EINVAL;
> > }
> > +
> > + spin_unlock(&dtdevs_lock);
> > break;
> > }
> >
> > + spin_unlock(&dtdevs_lock);
> You could then remove this one.
Ok!
>
> With the remarks addressed:
> Reviewed-by: Michal Orzel <michal.or...@amd.com>
>
> ~Michal
