| Message ID | 20230825080222.14247-10-vikram.garhwal@amd.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | dynamic node programming using overlay dtbo | expand |
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.garhwal@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). > { > 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()? > + 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. With the remarks addressed: Reviewed-by: Michal Orzel <michal.orzel@amd.com> ~Michal
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.garhwal@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.orzel@amd.com> > > ~Michal
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) { 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); + if ( domctl->cmd == XEN_DOMCTL_test_assign_device ) { - if ( iommu_dt_device_is_assigned(dev) ) + + 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); + if ( d == dom_io ) return -EINVAL;
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.garhwal@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(-)