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From: "Tian, Kevin" <kevin.tian@intel.com>
To: Kenneth Lee <nek.in.cn@gmail.com>,
	Jonathan Corbet <corbet@lwn.net>,
	Herbert Xu <herbert@gondor.apana.org.au>,
	"David S . Miller" <davem@davemloft.net>,
	Joerg Roedel <joro@8bytes.org>,
	Alex Williamson <alex.williamson@redhat.com>,
	Kenneth Lee <liguozhu@hisilicon.com>,
	Hao Fang <fanghao11@huawei.com>,
	Zhou Wang <wangzhou1@hisilicon.com>,
	Zaibo Xu <xuzaibo@huawei.com>,
	Philippe Ombredanne <pombredanne@nexb.com>,
	"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	"linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-crypto@vger.kernel.org" <linux-crypto@vger.kernel.org>,
	"iommu@lists.linux-foundation.org"
	<iommu@lists.linux-foundation.org>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	"linux-accelerators@lists.ozlabs.org" 
	<linux-accelerators@lists.ozlabs.org>,
	Lu Baolu <baolu.lu@linux.intel.com>,
	"Kumar, Sanjay K" <sanjay.k.kumar@intel.com>
Cc: "linuxarm@huawei.com" <linuxarm@huawei.com>
Subject: RE: [RFC PATCH 2/7] iommu: Add share domain interface in iommu for spimdev
Date: Thu, 2 Aug 2018 03:17:03 +0000
Message-ID: <AADFC41AFE54684AB9EE6CBC0274A5D191290F49@SHSMSX101.ccr.corp.intel.com> (raw)
In-Reply-To: <20180801102221.5308-3-nek.in.cn@gmail.com>

> From: Kenneth Lee
> Sent: Wednesday, August 1, 2018 6:22 PM
> 
> From: Kenneth Lee <liguozhu@hisilicon.com>
> 
> This patch add sharing interface for a iommu_group. The new interface:
> 
> 	iommu_group_share_domain()
> 	iommu_group_unshare_domain()
> 
> can be used by some virtual iommu_group (such as iommu_group for
> spimdev)
> to share their parent's iommu_group.
> 
> When the domain of the group is shared, it cannot be changed before
> unshared.  In the future, notification can be added if update is required.

Is it necessary or just asking VFIO to use parent domain directly? 

> 
> Signed-off-by: Kenneth Lee <liguozhu@hisilicon.com>
> ---
>  drivers/iommu/iommu.c | 28 +++++++++++++++++++++++++++-
>  include/linux/iommu.h |  2 ++
>  2 files changed, 29 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> index 63b37563db7e..a832aafe660d 100644
> --- a/drivers/iommu/iommu.c
> +++ b/drivers/iommu/iommu.c
> @@ -54,6 +54,9 @@ struct iommu_group {
>  	int id;
>  	struct iommu_domain *default_domain;
>  	struct iommu_domain *domain;
> +	atomic_t domain_shared_ref; /* Number of user of current domain.
> +				     * The domain cannot be modified if ref >
> 0
> +				     */
>  };
> 
>  struct group_device {
> @@ -353,6 +356,7 @@ struct iommu_group *iommu_group_alloc(void)
>  		return ERR_PTR(ret);
>  	}
>  	group->id = ret;
> +	atomic_set(&group->domain_shared_ref, 0);
> 
>  	ret = kobject_init_and_add(&group->kobj, &iommu_group_ktype,
>  				   NULL, "%d", group->id);
> @@ -482,6 +486,25 @@ int iommu_group_set_name(struct iommu_group
> *group, const char *name)
>  }
>  EXPORT_SYMBOL_GPL(iommu_group_set_name);
> 
> +struct iommu_domain *iommu_group_share_domain(struct
> iommu_group *group)
> +{
> +	/* the domain can be shared only when the default domain is used
> */
> +	/* todo: more shareable check */
> +	if (group->domain != group->default_domain)
> +		return ERR_PTR(-EINVAL);
> +
> +	atomic_inc(&group->domain_shared_ref);
> +	return group->domain;
> +}
> +EXPORT_SYMBOL_GPL(iommu_group_share_domain);
> +
> +void iommu_group_unshare_domain(struct iommu_group *group)
> +{
> +	atomic_dec(&group->domain_shared_ref);
> +	WARN_ON(atomic_read(&group->domain_shared_ref) < 0);
> +}
> +EXPORT_SYMBOL_GPL(iommu_group_unshare_domain);
> +
>  static int iommu_group_create_direct_mappings(struct iommu_group
> *group,
>  					      struct device *dev)
>  {
> @@ -1401,7 +1424,8 @@ static int __iommu_attach_group(struct
> iommu_domain *domain,
>  {
>  	int ret;
> 
> -	if (group->default_domain && group->domain != group-
> >default_domain)
> +	if ((group->default_domain && group->domain != group-
> >default_domain) ||
> +	     atomic_read(&group->domain_shared_ref) > 0)
>  		return -EBUSY;
> 
>  	ret = __iommu_group_for_each_dev(group, domain,
> @@ -1438,6 +1462,8 @@ static void __iommu_detach_group(struct
> iommu_domain *domain,
>  {
>  	int ret;
> 
> +	WARN_ON(atomic_read(&group->domain_shared_ref) > 0);
> +
>  	if (!group->default_domain) {
>  		__iommu_group_for_each_dev(group, domain,
>  					   iommu_group_do_detach_device);
> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> index 19938ee6eb31..278d60e3ec39 100644
> --- a/include/linux/iommu.h
> +++ b/include/linux/iommu.h
> @@ -349,6 +349,8 @@ extern int iommu_domain_get_attr(struct
> iommu_domain *domain, enum iommu_attr,
>  				 void *data);
>  extern int iommu_domain_set_attr(struct iommu_domain *domain, enum
> iommu_attr,
>  				 void *data);
> +extern struct iommu_domain *iommu_group_share_domain(struct
> iommu_group *group);
> +extern void iommu_group_unshare_domain(struct iommu_group *group);
> 
>  /* Window handling function prototypes */
>  extern int iommu_domain_window_enable(struct iommu_domain
> *domain, u32 wnd_nr,
> --
> 2.17.1


  reply index

Thread overview: 61+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-08-01 10:22 [RFC PATCH 0/7] A General Accelerator Framework, WarpDrive Kenneth Lee
2018-08-01 10:22 ` [RFC PATCH 1/7] vfio/spimdev: Add documents for WarpDrive framework Kenneth Lee
2018-08-02  3:14   ` Tian, Kevin
2018-08-02  4:22     ` Kenneth Lee
2018-08-02  4:41       ` Tian, Kevin
2018-08-06 12:27   ` Pavel Machek
2018-08-08  1:43     ` Kenneth Lee
2018-08-01 10:22 ` [RFC PATCH 2/7] iommu: Add share domain interface in iommu for spimdev Kenneth Lee
2018-08-02  3:17   ` Tian, Kevin [this message]
2018-08-02  4:15     ` Kenneth Lee
2018-08-02  4:39       ` Tian, Kevin
2018-08-08  9:13   ` Joerg Roedel
2018-08-09  1:09     ` Kenneth Lee
2018-08-01 10:22 ` [RFC PATCH 3/7] vfio: add spimdev support Kenneth Lee
2018-08-01 16:23   ` Randy Dunlap
2018-08-02  3:07     ` Kenneth Lee
2018-08-02  3:21   ` Tian, Kevin
2018-08-02  3:47     ` Kenneth Lee
2018-08-02  4:24       ` Tian, Kevin
2018-08-02  7:34         ` Kenneth Lee
     [not found]           ` <20180802103528.0b863030.cohuck@redhat.com>
     [not found]             ` <20180802124327.403b10ab@t450s.home>
2018-08-06  1:40               ` Kenneth Lee
2018-08-06 15:49                 ` Alex Williamson
2018-08-06 16:34                   ` Raj, Ashok
2018-08-06 17:05                     ` Alex Williamson
2018-08-08  1:32                       ` Kenneth Lee
2018-08-01 10:22 ` [RFC PATCH 4/7] crypto: add hisilicon Queue Manager driver Kenneth Lee
2018-08-01 10:22 ` [RFC PATCH 5/7] crypto: Add Hisilicon Zip driver Kenneth Lee
2018-08-01 10:22 ` [RFC PATCH 6/7] crypto: add spimdev support to Hisilicon QM Kenneth Lee
2018-08-01 10:22 ` [RFC PATCH 7/7] vfio/spimdev: add user sample for spimdev Kenneth Lee
2018-08-01 16:56 ` [RFC PATCH 0/7] A General Accelerator Framework, WarpDrive Jerome Glisse
2018-08-02  2:33   ` Tian, Kevin
2018-08-02  4:05     ` Kenneth Lee
2018-08-02 14:22       ` Jerome Glisse
2018-08-03  3:47         ` Kenneth Lee
2018-08-03 14:39           ` Jerome Glisse
2018-08-06  3:12             ` Kenneth Lee
2018-08-06 15:32               ` Jerome Glisse
2018-08-08  1:08                 ` Kenneth Lee
2018-08-08 15:18                   ` Jerome Glisse
2018-08-09  8:03                     ` Kenneth Lee
2018-08-09  8:31                       ` Tian, Kevin
2018-08-10  1:37                         ` Kenneth Lee
2018-08-09 14:46                       ` Jerome Glisse
2018-08-10  3:39                         ` Kenneth Lee
2018-08-10 13:12                           ` Jean-Philippe Brucker
2018-08-11 15:26                             ` Kenneth Lee
2018-08-13  9:29                               ` Kenneth Lee
2018-08-13 19:23                                 ` Jerome Glisse
2018-08-14  3:46                                   ` Kenneth Lee
2018-08-10 14:32                           ` Jerome Glisse
2018-08-11 14:44                             ` Kenneth Lee
2018-08-02 10:10     ` Alan Cox
2018-08-02 12:24       ` Xu Zaibo
2018-08-02 14:46       ` Jerome Glisse
2018-08-03 14:20         ` Alan Cox
2018-08-03 14:55           ` Jerome Glisse
2018-08-06  1:26           ` Kenneth Lee
2018-08-02  2:59 ` Tian, Kevin
2018-08-02  3:40   ` Kenneth Lee
2018-08-02  4:36     ` Tian, Kevin
2018-08-02  5:35       ` Kenneth Lee

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