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From: Jacob Pan <jacob.jun.pan@linux.intel.com>
To: "Tian, Kevin" <kevin.tian@intel.com>
Cc: "Raj, Ashok" <ashok.raj@intel.com>,
	Jean-Philippe Brucker <jean-philippe@linaro.com>,
	LKML <linux-kernel@vger.kernel.org>,
	"iommu@lists.linux-foundation.org"
	<iommu@lists.linux-foundation.org>,
	Alex Williamson <alex.williamson@redhat.com>,
	David Woodhouse <dwmw2@infradead.org>,
	Jonathan Cameron <jic23@kernel.org>
Subject: Re: [PATCH 09/10] iommu/ioasid: Support ioasid_set quota adjustment
Date: Fri, 27 Mar 2020 16:30:57 -0700	[thread overview]
Message-ID: <20200327163057.75a0e154@jacob-builder> (raw)
In-Reply-To: <AADFC41AFE54684AB9EE6CBC0274A5D19D7ED605@SHSMSX104.ccr.corp.intel.com>

On Fri, 27 Mar 2020 10:09:04 +0000
"Tian, Kevin" <kevin.tian@intel.com> wrote:

> > From: Jacob Pan <jacob.jun.pan@linux.intel.com>
> > Sent: Thursday, March 26, 2020 1:56 AM
> > 
> > IOASID set is allocated with an initial quota, at runtime there may
> > be needs to balance IOASID resources among different VMs/sets.
> >   
> 
> I may overlook previous patches but I didn't see any place setting the
> initial quota...
> 
Initial quota is in place when the ioasid_set is allocated.

> > This patch adds a new API to adjust per set quota.  
> 
> since this is purely an internal kernel API, implies that the
> publisher (e.g. VFIO) is responsible for exposing its own uAPI to set
> the quota?
> 
yes, VFIO will do the adjustment. I think Alex suggested module
parameters.

> > 
> > Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
> > ---
> >  drivers/iommu/ioasid.c | 44
> > ++++++++++++++++++++++++++++++++++++++++++++
> >  include/linux/ioasid.h |  6 ++++++
> >  2 files changed, 50 insertions(+)
> > 
> > diff --git a/drivers/iommu/ioasid.c b/drivers/iommu/ioasid.c
> > index 27dce2cb5af2..5ac28862a1db 100644
> > --- a/drivers/iommu/ioasid.c
> > +++ b/drivers/iommu/ioasid.c
> > @@ -578,6 +578,50 @@ void ioasid_free_set(int sid, bool destroy_set)
> >  }
> >  EXPORT_SYMBOL_GPL(ioasid_free_set);
> > 
> > +/**
> > + * ioasid_adjust_set - Adjust the quota of an IOASID set
> > + * @quota:	Quota allowed in this set
> > + * @sid:	IOASID set ID to be assigned
> > + *
> > + * Return 0 on success. If the new quota is smaller than the
> > number of
> > + * IOASIDs already allocated, -EINVAL will be returned. No change
> > will be
> > + * made to the existing quota.
> > + */
> > +int ioasid_adjust_set(int sid, int quota)
> > +{
> > +	struct ioasid_set_data *sdata;
> > +	int ret = 0;
> > +
> > +	mutex_lock(&ioasid_allocator_lock);
> > +	sdata = xa_load(&ioasid_sets, sid);
> > +	if (!sdata || sdata->nr_ioasids > quota) {
> > +		pr_err("Failed to adjust IOASID set %d quota %d\n",
> > +			sid, quota);
> > +		ret = -EINVAL;
> > +		goto done_unlock;
> > +	}
> > +
> > +	if (quota >= ioasid_capacity_avail) {
> > +		ret = -ENOSPC;
> > +		goto done_unlock;
> > +	}
> > +
> > +	/* Return the delta back to system pool */
> > +	ioasid_capacity_avail += sdata->size - quota;
> > +
> > +	/*
> > +	 * May have a policy to prevent giving all available
> > IOASIDs
> > +	 * to one set. But we don't enforce here, it should be in
> > the
> > +	 * upper layers.
> > +	 */
> > +	sdata->size = quota;
> > +
> > +done_unlock:
> > +	mutex_unlock(&ioasid_allocator_lock);
> > +
> > +	return ret;
> > +}
> > +EXPORT_SYMBOL_GPL(ioasid_adjust_set);
> > 
> >  /**
> >   * ioasid_find - Find IOASID data
> > diff --git a/include/linux/ioasid.h b/include/linux/ioasid.h
> > index 32d032913828..6e7de6fb91bf 100644
> > --- a/include/linux/ioasid.h
> > +++ b/include/linux/ioasid.h
> > @@ -73,6 +73,7 @@ int ioasid_alloc_set(struct ioasid_set *token,
> > ioasid_t quota, int *sid);
> >  void ioasid_free_set(int sid, bool destroy_set);
> >  int ioasid_find_sid(ioasid_t ioasid);
> >  int ioasid_notify(ioasid_t id, enum ioasid_notify_val cmd);
> > +int ioasid_adjust_set(int sid, int quota);
> > 
> >  #else /* !CONFIG_IOASID */
> >  static inline ioasid_t ioasid_alloc(int sid, ioasid_t min,
> > @@ -136,5 +137,10 @@ static inline int ioasid_alloc_system_set(int
> > quota) return -ENOTSUPP;
> >  }
> > 
> > +static inline int ioasid_adjust_set(int sid, int quota)
> > +{
> > +	return -ENOTSUPP;
> > +}
> > +
> >  #endif /* CONFIG_IOASID */
> >  #endif /* __LINUX_IOASID_H */
> > --
> > 2.7.4  
> 

[Jacob Pan]
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  reply	other threads:[~2020-03-27 23:25 UTC|newest]

Thread overview: 57+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-25 17:55 [PATCH 00/10] IOASID extensions for guest SVA Jacob Pan
2020-03-25 17:55 ` [PATCH 01/10] iommu/ioasid: Introduce system-wide capacity Jacob Pan
2020-03-27  8:07   ` Tian, Kevin
2020-03-27 16:08     ` Jacob Pan
2020-04-01 13:45   ` Jean-Philippe Brucker
2020-04-01 22:50     ` Jacob Pan
2020-03-25 17:55 ` [PATCH 02/10] iommu/vt-d: Set IOASID capacity when SVM is enabled Jacob Pan
2020-03-27  8:08   ` Tian, Kevin
2020-03-25 17:55 ` [PATCH 03/10] iommu/ioasid: Introduce per set allocation APIs Jacob Pan
2020-03-26  2:12   ` Lu Baolu
2020-03-26 21:30     ` Jacob Pan
2020-03-27  8:38   ` Tian, Kevin
2020-03-27 16:59     ` Jacob Pan
2020-03-28  6:32       ` Tian, Kevin
2020-04-01 13:47   ` Jean-Philippe Brucker
2020-04-06 20:02     ` Jacob Pan
2020-04-07 11:01       ` Jean-Philippe Brucker
2020-04-21 21:51         ` Jacob Pan
2020-03-25 17:55 ` [PATCH 04/10] iommu/ioasid: Rename ioasid_set_data to avoid confusion with ioasid_set Jacob Pan
2020-03-27  9:35   ` Tian, Kevin
2020-03-25 17:55 ` [PATCH 05/10] iommu/ioasid: Create an IOASID set for host SVA use Jacob Pan
2020-03-27  9:41   ` Tian, Kevin
2020-03-27 17:28     ` Jacob Pan
2020-03-28  6:33       ` Tian, Kevin
2020-04-01 13:53   ` Jean-Philippe Brucker
2020-04-06 15:33     ` Jacob Pan
2020-04-07 11:01       ` Jean-Philippe Brucker
2020-04-13 22:06         ` Jacob Pan
2020-04-15 15:10           ` Jean-Philippe Brucker
2020-03-25 17:55 ` [PATCH 06/10] iommu/ioasid: Convert to set aware allocations Jacob Pan
2020-03-27  9:54   ` Tian, Kevin
2020-03-27 17:41     ` Jacob Pan
2020-03-28  6:40       ` Tian, Kevin
2020-04-06 20:07         ` Jacob Pan
2020-04-01 13:55   ` Jean-Philippe Brucker
2020-04-01 22:45     ` Jacob Pan
2020-03-25 17:55 ` [PATCH 07/10] iommu/ioasid: Use mutex instead of spinlock Jacob Pan
2020-03-27  9:55   ` Tian, Kevin
2020-04-01 13:58   ` Jean-Philippe Brucker
2020-03-25 17:55 ` [PATCH 08/10] iommu/ioasid: Introduce notifier APIs Jacob Pan
2020-03-27 10:03   ` Tian, Kevin
2020-03-27 18:36     ` Jacob Pan
2020-03-28  6:43       ` Tian, Kevin
2020-03-31 15:13         ` Jacob Pan
2020-04-01 14:00   ` Jean-Philippe Brucker
2020-04-10 15:43     ` Jacob Pan
2020-03-25 17:55 ` [PATCH 09/10] iommu/ioasid: Support ioasid_set quota adjustment Jacob Pan
2020-03-27 10:09   ` Tian, Kevin
2020-03-27 23:30     ` Jacob Pan [this message]
2020-03-28  6:44       ` Tian, Kevin
2020-03-25 17:55 ` [PATCH 10/10] iommu/vt-d: Register PASID notifier for status change Jacob Pan
2020-03-27 10:22   ` Tian, Kevin
2020-03-27 23:47     ` Jacob Pan
2020-04-01 14:03 ` [PATCH 00/10] IOASID extensions for guest SVA Jean-Philippe Brucker
2020-04-01 23:38   ` Jacob Pan
2020-04-02 12:26     ` Jean-Philippe Brucker
2020-04-02 16:09       ` Jacob Pan

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