Re: [PATCH v3 2/6] vfio/type1: Check reserve region conflict and update iova list

2018-02-19 Thread Alex Williamson 
On Mon, 19 Feb 2018 10:00:53 +
Shameerali Kolothum Thodi  wrote:

> > -Original Message-
> > From: Alex Williamson [mailto:alex.william...@redhat.com]
> > Sent: Friday, February 16, 2018 9:18 PM
> > 
> > On Thu, 15 Feb 2018 09:45:00 +
> > Shameer Kolothum  wrote:
> > > + iommu_get_group_resv_regions(iommu_group, _resv_regions);
> > > +
> > > + if (vfio_iommu_resv_conflict(iommu, _resv_regions)) {
> > > + ret = -EINVAL;
> > > + goto out_detach;
> > > + }
> > > +
> > >   /* Get a copy of the current iova list and work on it */
> > >   INIT_LIST_HEAD(_copy);
> > >   ret = vfio_iommu_get_iova_copy(iommu, _copy);
> > > @@ -1437,6 +1512,10 @@ static int vfio_iommu_type1_attach_group(void  
> > *iommu_data,  
> > >   if (ret)
> > >   goto out_detach;
> > >
> > > + ret = vfio_iommu_resv_exclude(_copy, _resv_regions);
> > > + if (ret)
> > > + goto out_detach;
> > > +
> > >   resv_msi = vfio_iommu_has_sw_msi(iommu_group, _msi_base);
> > >
> > >   INIT_LIST_HEAD(>group_list);
> > > @@ -1497,6 +1576,9 @@ static int vfio_iommu_type1_attach_group(void  
> > *iommu_data,  
> > >   /* Delete the old one and insert new iova list */
> > >   vfio_iommu_insert_iova_copy(iommu, _copy);
> > >
> > > + list_for_each_entry_safe(resv, resv_next, _resv_regions, list)
> > > + kfree(resv);  
> > 
> > list_del() here and below, also this can be done after the mutex unlock.  
> 
> Ok. I thought that as the reserved regions are local to this function, 
> list_del() is
> not required.  Same for the iova_copy in the first patch as well(which I 
> missed to
> comment there).

What you have works (afaik), it just seems sloppy to me to have free'd
entries in the list, even as the destructor, as this is not a
performance critical path.  Is this more common elsewhere in the kernel
than I suspect?  Thanks,

Alex

Re: [PATCH v3 2/6] vfio/type1: Check reserve region conflict and update iova list

2018-02-19 Thread Alex Williamson 
On Mon, 19 Feb 2018 10:00:53 +
Shameerali Kolothum Thodi  wrote:

> > -Original Message-
> > From: Alex Williamson [mailto:alex.william...@redhat.com]
> > Sent: Friday, February 16, 2018 9:18 PM
> > 
> > On Thu, 15 Feb 2018 09:45:00 +
> > Shameer Kolothum  wrote:
> > > + iommu_get_group_resv_regions(iommu_group, _resv_regions);
> > > +
> > > + if (vfio_iommu_resv_conflict(iommu, _resv_regions)) {
> > > + ret = -EINVAL;
> > > + goto out_detach;
> > > + }
> > > +
> > >   /* Get a copy of the current iova list and work on it */
> > >   INIT_LIST_HEAD(_copy);
> > >   ret = vfio_iommu_get_iova_copy(iommu, _copy);
> > > @@ -1437,6 +1512,10 @@ static int vfio_iommu_type1_attach_group(void  
> > *iommu_data,  
> > >   if (ret)
> > >   goto out_detach;
> > >
> > > + ret = vfio_iommu_resv_exclude(_copy, _resv_regions);
> > > + if (ret)
> > > + goto out_detach;
> > > +
> > >   resv_msi = vfio_iommu_has_sw_msi(iommu_group, _msi_base);
> > >
> > >   INIT_LIST_HEAD(>group_list);
> > > @@ -1497,6 +1576,9 @@ static int vfio_iommu_type1_attach_group(void  
> > *iommu_data,  
> > >   /* Delete the old one and insert new iova list */
> > >   vfio_iommu_insert_iova_copy(iommu, _copy);
> > >
> > > + list_for_each_entry_safe(resv, resv_next, _resv_regions, list)
> > > + kfree(resv);  
> > 
> > list_del() here and below, also this can be done after the mutex unlock.  
> 
> Ok. I thought that as the reserved regions are local to this function, 
> list_del() is
> not required.  Same for the iova_copy in the first patch as well(which I 
> missed to
> comment there).

What you have works (afaik), it just seems sloppy to me to have free'd
entries in the list, even as the destructor, as this is not a
performance critical path.  Is this more common elsewhere in the kernel
than I suspect?  Thanks,

Alex

RE: [PATCH v3 2/6] vfio/type1: Check reserve region conflict and update iova list

2018-02-19 Thread Shameerali Kolothum Thodi 


> -Original Message-
> From: Alex Williamson [mailto:alex.william...@redhat.com]
> Sent: Friday, February 16, 2018 9:18 PM
> To: Shameerali Kolothum Thodi <shameerali.kolothum.th...@huawei.com>
> Cc: eric.au...@redhat.com; pmo...@linux.vnet.ibm.com;
> k...@vger.kernel.org; linux-kernel@vger.kernel.org; Linuxarm
> <linux...@huawei.com>; John Garry <john.ga...@huawei.com>; xuwei (O)
> <xuw...@huawei.com>
> Subject: Re: [PATCH v3 2/6] vfio/type1: Check reserve region conflict and
> update iova list
> 
> On Thu, 15 Feb 2018 09:45:00 +
> Shameer Kolothum <shameerali.kolothum.th...@huawei.com> wrote:
> 
> > This retrieves the reserved regions associated with dev group and
> > checks for conflicts with any existing dma mappings. Also update
> > the iova list excluding the reserved regions.
> >
> > Signed-off-by: Shameer Kolothum <shameerali.kolothum.th...@huawei.com>
> > ---
> >  drivers/vfio/vfio_iommu_type1.c | 86
> -
> >  1 file changed, 85 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/vfio/vfio_iommu_type1.c
> b/drivers/vfio/vfio_iommu_type1.c
> > index 4726f55..4db87a9 100644
> > --- a/drivers/vfio/vfio_iommu_type1.c
> > +++ b/drivers/vfio/vfio_iommu_type1.c
> > @@ -1303,6 +1303,72 @@ static int vfio_iommu_aper_resize(struct
> list_head *iova,
> > return 0;
> >  }
> >
> > +/*
> > + * Check reserved region conflicts with existing dma mappings
> > + */
> > +static bool vfio_iommu_resv_conflict(struct vfio_iommu *iommu,
> > +   struct list_head *resv_regions)
> > +{
> > +   struct iommu_resv_region *region;
> > +
> > +   /* Check for conflict with existing dma mappings */
> > +   list_for_each_entry(region, resv_regions, list) {
> > +   if (vfio_find_dma(iommu, region->start, region->length))
> > +   return true;
> > +   }
> > +
> > +   return false;
> > +}
> > +
> > +/*
> > + * Check iova region overlap with  reserved regions and
> > + * exclude them from the iommu iova range
> > + */
> > +static int vfio_iommu_resv_exclude(struct list_head *iova,
> > +   struct list_head *resv_regions)
> > +{
> > +   struct iommu_resv_region *resv;
> > +   struct vfio_iova *n, *next;
> > +
> > +   list_for_each_entry(resv, resv_regions, list) {
> > +   phys_addr_t start, end;
> > +
> > +   start = resv->start;
> > +   end = resv->start + resv->length - 1;
> > +
> > +   list_for_each_entry_safe(n, next, iova, list) {
> > +   int ret = 0;
> > +
> > +   /* No overlap */
> > +   if ((start > n->end) || (end < n->start))
> > +   continue;
> > +   /*
> > +* Insert a new node if current node overlaps with the
> > +* reserve region to exlude that from valid iova range.
> > +* Note that, new node is inserted before the current
> > +* node and finally the current node is deleted keeping
> > +* the list updated and sorted.
> > +*/
> > +   if (start > n->start)
> > +   ret = vfio_insert_iova(n->start, start - 1,
> > +>list);
> > +   if (!ret && end < n->end)
> > +   ret = vfio_insert_iova(end + 1, n->end,
> > +>list);
> > +   if (ret)
> > +   return ret;
> > +
> > +   list_del(>list);
> > +   kfree(n);
> > +   }
> > +   }
> > +
> > +   if (list_empty(iova))
> > +   return -EINVAL;
> > +
> > +   return 0;
> > +}
> > +
> >  static int vfio_iommu_get_iova_copy(struct vfio_iommu *iommu,
> > struct list_head *iova_copy)
> >  {
> > @@ -1346,7 +1412,8 @@ static int vfio_iommu_type1_attach_group(void
> *iommu_data,
> > bool resv_msi, msi_remap;
> > phys_addr_t resv_msi_base;
> > struct iommu_domain_geometry geo;
> > -   struct list_head iova_copy;
> > +   struct list_head iova_copy, group_resv_regions;
> > +   struct iommu_resv_region *resv, *resv

RE: [PATCH v3 2/6] vfio/type1: Check reserve region conflict and update iova list

2018-02-19 Thread Shameerali Kolothum Thodi 


> -Original Message-
> From: Alex Williamson [mailto:alex.william...@redhat.com]
> Sent: Friday, February 16, 2018 9:18 PM
> To: Shameerali Kolothum Thodi 
> Cc: eric.au...@redhat.com; pmo...@linux.vnet.ibm.com;
> k...@vger.kernel.org; linux-kernel@vger.kernel.org; Linuxarm
> ; John Garry ; xuwei (O)
> 
> Subject: Re: [PATCH v3 2/6] vfio/type1: Check reserve region conflict and
> update iova list
> 
> On Thu, 15 Feb 2018 09:45:00 +
> Shameer Kolothum  wrote:
> 
> > This retrieves the reserved regions associated with dev group and
> > checks for conflicts with any existing dma mappings. Also update
> > the iova list excluding the reserved regions.
> >
> > Signed-off-by: Shameer Kolothum 
> > ---
> >  drivers/vfio/vfio_iommu_type1.c | 86
> -
> >  1 file changed, 85 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/vfio/vfio_iommu_type1.c
> b/drivers/vfio/vfio_iommu_type1.c
> > index 4726f55..4db87a9 100644
> > --- a/drivers/vfio/vfio_iommu_type1.c
> > +++ b/drivers/vfio/vfio_iommu_type1.c
> > @@ -1303,6 +1303,72 @@ static int vfio_iommu_aper_resize(struct
> list_head *iova,
> > return 0;
> >  }
> >
> > +/*
> > + * Check reserved region conflicts with existing dma mappings
> > + */
> > +static bool vfio_iommu_resv_conflict(struct vfio_iommu *iommu,
> > +   struct list_head *resv_regions)
> > +{
> > +   struct iommu_resv_region *region;
> > +
> > +   /* Check for conflict with existing dma mappings */
> > +   list_for_each_entry(region, resv_regions, list) {
> > +   if (vfio_find_dma(iommu, region->start, region->length))
> > +   return true;
> > +   }
> > +
> > +   return false;
> > +}
> > +
> > +/*
> > + * Check iova region overlap with  reserved regions and
> > + * exclude them from the iommu iova range
> > + */
> > +static int vfio_iommu_resv_exclude(struct list_head *iova,
> > +   struct list_head *resv_regions)
> > +{
> > +   struct iommu_resv_region *resv;
> > +   struct vfio_iova *n, *next;
> > +
> > +   list_for_each_entry(resv, resv_regions, list) {
> > +   phys_addr_t start, end;
> > +
> > +   start = resv->start;
> > +   end = resv->start + resv->length - 1;
> > +
> > +   list_for_each_entry_safe(n, next, iova, list) {
> > +   int ret = 0;
> > +
> > +   /* No overlap */
> > +   if ((start > n->end) || (end < n->start))
> > +   continue;
> > +   /*
> > +* Insert a new node if current node overlaps with the
> > +* reserve region to exlude that from valid iova range.
> > +* Note that, new node is inserted before the current
> > +* node and finally the current node is deleted keeping
> > +* the list updated and sorted.
> > +*/
> > +   if (start > n->start)
> > +   ret = vfio_insert_iova(n->start, start - 1,
> > +>list);
> > +   if (!ret && end < n->end)
> > +   ret = vfio_insert_iova(end + 1, n->end,
> > +>list);
> > +   if (ret)
> > +   return ret;
> > +
> > +   list_del(>list);
> > +   kfree(n);
> > +   }
> > +   }
> > +
> > +   if (list_empty(iova))
> > +   return -EINVAL;
> > +
> > +   return 0;
> > +}
> > +
> >  static int vfio_iommu_get_iova_copy(struct vfio_iommu *iommu,
> > struct list_head *iova_copy)
> >  {
> > @@ -1346,7 +1412,8 @@ static int vfio_iommu_type1_attach_group(void
> *iommu_data,
> > bool resv_msi, msi_remap;
> > phys_addr_t resv_msi_base;
> > struct iommu_domain_geometry geo;
> > -   struct list_head iova_copy;
> > +   struct list_head iova_copy, group_resv_regions;
> > +   struct iommu_resv_region *resv, *resv_next;
> > struct vfio_iova *iova, *iova_next;
> >
> > mutex_lock(>lock);
> > @@ -1426,6 +1493,14 @@ static int vfio_iommu_type1_attach_group(void
> *iommu_data,
> >

Re: [PATCH v3 2/6] vfio/type1: Check reserve region conflict and update iova list

2018-02-16 Thread Alex Williamson 
On Thu, 15 Feb 2018 09:45:00 +
Shameer Kolothum  wrote:

> This retrieves the reserved regions associated with dev group and
> checks for conflicts with any existing dma mappings. Also update
> the iova list excluding the reserved regions.
> 
> Signed-off-by: Shameer Kolothum 
> ---
>  drivers/vfio/vfio_iommu_type1.c | 86 
> -
>  1 file changed, 85 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
> index 4726f55..4db87a9 100644
> --- a/drivers/vfio/vfio_iommu_type1.c
> +++ b/drivers/vfio/vfio_iommu_type1.c
> @@ -1303,6 +1303,72 @@ static int vfio_iommu_aper_resize(struct list_head 
> *iova,
>   return 0;
>  }
>  
> +/*
> + * Check reserved region conflicts with existing dma mappings
> + */
> +static bool vfio_iommu_resv_conflict(struct vfio_iommu *iommu,
> + struct list_head *resv_regions)
> +{
> + struct iommu_resv_region *region;
> +
> + /* Check for conflict with existing dma mappings */
> + list_for_each_entry(region, resv_regions, list) {
> + if (vfio_find_dma(iommu, region->start, region->length))
> + return true;
> + }
> +
> + return false;
> +}
> +
> +/*
> + * Check iova region overlap with  reserved regions and
> + * exclude them from the iommu iova range
> + */
> +static int vfio_iommu_resv_exclude(struct list_head *iova,
> + struct list_head *resv_regions)
> +{
> + struct iommu_resv_region *resv;
> + struct vfio_iova *n, *next;
> +
> + list_for_each_entry(resv, resv_regions, list) {
> + phys_addr_t start, end;
> +
> + start = resv->start;
> + end = resv->start + resv->length - 1;
> +
> + list_for_each_entry_safe(n, next, iova, list) {
> + int ret = 0;
> +
> + /* No overlap */
> + if ((start > n->end) || (end < n->start))
> + continue;
> + /*
> +  * Insert a new node if current node overlaps with the
> +  * reserve region to exlude that from valid iova range.
> +  * Note that, new node is inserted before the current
> +  * node and finally the current node is deleted keeping
> +  * the list updated and sorted.
> +  */
> + if (start > n->start)
> + ret = vfio_insert_iova(n->start, start - 1,
> +  >list);
> + if (!ret && end < n->end)
> + ret = vfio_insert_iova(end + 1, n->end,
> +  >list);
> + if (ret)
> + return ret;
> +
> + list_del(>list);
> + kfree(n);
> + }
> + }
> +
> + if (list_empty(iova))
> + return -EINVAL;
> +
> + return 0;
> +}
> +
>  static int vfio_iommu_get_iova_copy(struct vfio_iommu *iommu,
>   struct list_head *iova_copy)
>  {
> @@ -1346,7 +1412,8 @@ static int vfio_iommu_type1_attach_group(void 
> *iommu_data,
>   bool resv_msi, msi_remap;
>   phys_addr_t resv_msi_base;
>   struct iommu_domain_geometry geo;
> - struct list_head iova_copy;
> + struct list_head iova_copy, group_resv_regions;
> + struct iommu_resv_region *resv, *resv_next;
>   struct vfio_iova *iova, *iova_next;
>  
>   mutex_lock(>lock);
> @@ -1426,6 +1493,14 @@ static int vfio_iommu_type1_attach_group(void 
> *iommu_data,
>   goto out_detach;
>   }
>  
> + INIT_LIST_HEAD(_resv_regions);

LIST_HEAD()

> + iommu_get_group_resv_regions(iommu_group, _resv_regions);
> +
> + if (vfio_iommu_resv_conflict(iommu, _resv_regions)) {
> + ret = -EINVAL;
> + goto out_detach;
> + }
> +
>   /* Get a copy of the current iova list and work on it */
>   INIT_LIST_HEAD(_copy);
>   ret = vfio_iommu_get_iova_copy(iommu, _copy);
> @@ -1437,6 +1512,10 @@ static int vfio_iommu_type1_attach_group(void 
> *iommu_data,
>   if (ret)
>   goto out_detach;
>  
> + ret = vfio_iommu_resv_exclude(_copy, _resv_regions);
> + if (ret)
> + goto out_detach;
> +
>   resv_msi = vfio_iommu_has_sw_msi(iommu_group, _msi_base);
>  
>   INIT_LIST_HEAD(>group_list);
> @@ -1497,6 +1576,9 @@ static int vfio_iommu_type1_attach_group(void 
> *iommu_data,
>   /* Delete the old one and insert new iova list */
>   vfio_iommu_insert_iova_copy(iommu, _copy);
>  
> + list_for_each_entry_safe(resv, resv_next, _resv_regions, list)
> + kfree(resv);

list_del() here and

Re: [PATCH v3 2/6] vfio/type1: Check reserve region conflict and update iova list

2018-02-16 Thread Alex Williamson 
On Thu, 15 Feb 2018 09:45:00 +
Shameer Kolothum  wrote:

> This retrieves the reserved regions associated with dev group and
> checks for conflicts with any existing dma mappings. Also update
> the iova list excluding the reserved regions.
> 
> Signed-off-by: Shameer Kolothum 
> ---
>  drivers/vfio/vfio_iommu_type1.c | 86 
> -
>  1 file changed, 85 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
> index 4726f55..4db87a9 100644
> --- a/drivers/vfio/vfio_iommu_type1.c
> +++ b/drivers/vfio/vfio_iommu_type1.c
> @@ -1303,6 +1303,72 @@ static int vfio_iommu_aper_resize(struct list_head 
> *iova,
>   return 0;
>  }
>  
> +/*
> + * Check reserved region conflicts with existing dma mappings
> + */
> +static bool vfio_iommu_resv_conflict(struct vfio_iommu *iommu,
> + struct list_head *resv_regions)
> +{
> + struct iommu_resv_region *region;
> +
> + /* Check for conflict with existing dma mappings */
> + list_for_each_entry(region, resv_regions, list) {
> + if (vfio_find_dma(iommu, region->start, region->length))
> + return true;
> + }
> +
> + return false;
> +}
> +
> +/*
> + * Check iova region overlap with  reserved regions and
> + * exclude them from the iommu iova range
> + */
> +static int vfio_iommu_resv_exclude(struct list_head *iova,
> + struct list_head *resv_regions)
> +{
> + struct iommu_resv_region *resv;
> + struct vfio_iova *n, *next;
> +
> + list_for_each_entry(resv, resv_regions, list) {
> + phys_addr_t start, end;
> +
> + start = resv->start;
> + end = resv->start + resv->length - 1;
> +
> + list_for_each_entry_safe(n, next, iova, list) {
> + int ret = 0;
> +
> + /* No overlap */
> + if ((start > n->end) || (end < n->start))
> + continue;
> + /*
> +  * Insert a new node if current node overlaps with the
> +  * reserve region to exlude that from valid iova range.
> +  * Note that, new node is inserted before the current
> +  * node and finally the current node is deleted keeping
> +  * the list updated and sorted.
> +  */
> + if (start > n->start)
> + ret = vfio_insert_iova(n->start, start - 1,
> +  >list);
> + if (!ret && end < n->end)
> + ret = vfio_insert_iova(end + 1, n->end,
> +  >list);
> + if (ret)
> + return ret;
> +
> + list_del(>list);
> + kfree(n);
> + }
> + }
> +
> + if (list_empty(iova))
> + return -EINVAL;
> +
> + return 0;
> +}
> +
>  static int vfio_iommu_get_iova_copy(struct vfio_iommu *iommu,
>   struct list_head *iova_copy)
>  {
> @@ -1346,7 +1412,8 @@ static int vfio_iommu_type1_attach_group(void 
> *iommu_data,
>   bool resv_msi, msi_remap;
>   phys_addr_t resv_msi_base;
>   struct iommu_domain_geometry geo;
> - struct list_head iova_copy;
> + struct list_head iova_copy, group_resv_regions;
> + struct iommu_resv_region *resv, *resv_next;
>   struct vfio_iova *iova, *iova_next;
>  
>   mutex_lock(>lock);
> @@ -1426,6 +1493,14 @@ static int vfio_iommu_type1_attach_group(void 
> *iommu_data,
>   goto out_detach;
>   }
>  
> + INIT_LIST_HEAD(_resv_regions);

LIST_HEAD()

> + iommu_get_group_resv_regions(iommu_group, _resv_regions);
> +
> + if (vfio_iommu_resv_conflict(iommu, _resv_regions)) {
> + ret = -EINVAL;
> + goto out_detach;
> + }
> +
>   /* Get a copy of the current iova list and work on it */
>   INIT_LIST_HEAD(_copy);
>   ret = vfio_iommu_get_iova_copy(iommu, _copy);
> @@ -1437,6 +1512,10 @@ static int vfio_iommu_type1_attach_group(void 
> *iommu_data,
>   if (ret)
>   goto out_detach;
>  
> + ret = vfio_iommu_resv_exclude(_copy, _resv_regions);
> + if (ret)
> + goto out_detach;
> +
>   resv_msi = vfio_iommu_has_sw_msi(iommu_group, _msi_base);
>  
>   INIT_LIST_HEAD(>group_list);
> @@ -1497,6 +1576,9 @@ static int vfio_iommu_type1_attach_group(void 
> *iommu_data,
>   /* Delete the old one and insert new iova list */
>   vfio_iommu_insert_iova_copy(iommu, _copy);
>  
> + list_for_each_entry_safe(resv, resv_next, _resv_regions, list)
> + kfree(resv);

list_del() here and below, also this can be done after the mutex unlock.

> +
>