From: Jacob Pan <jacob.jun.pan@linux.intel.com>
To: Lu Baolu <baolu.lu@linux.intel.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
iommu@lists.linux-foundation.org, Joerg Roedel <joro@8bytes.org>,
David Woodhouse <dwmw2@infradead.org>,
Raj Ashok <ashok.raj@intel.com>, Yi Liu <yi.l.liu@intel.com>,
jacob.jun.pan@linux.intel.com
Subject: Re: [PATCH 1/3] iommu/vt-d: Remove redundant IOTLB flush
Date: Fri, 20 Mar 2020 09:20:47 -0700 [thread overview]
Message-ID: <20200320092047.4a4cf551@jacob-builder> (raw)
In-Reply-To: <26ab1917-f087-aafa-e861-6a2478000a6f@linux.intel.com>
On Fri, 20 Mar 2020 21:45:26 +0800
Lu Baolu <baolu.lu@linux.intel.com> wrote:
> On 2020/3/20 12:32, Jacob Pan wrote:
> > IOTLB flush already included in the PASID tear down process. There
> > is no need to flush again.
>
> It seems that intel_pasid_tear_down_entry() doesn't flush the pasid
> based device TLB?
>
I saw this code in intel_pasid_tear_down_entry(). Isn't the last line
flush the devtlb? Not in guest of course since the passdown tlb flush
is inclusive.
pasid_cache_invalidation_with_pasid(iommu, did, pasid);
iotlb_invalidation_with_pasid(iommu, did, pasid);
/* Device IOTLB doesn't need to be flushed in caching mode. */
if (!cap_caching_mode(iommu->cap))
devtlb_invalidation_with_pasid(iommu, dev, pasid);
> Best regards,
> baolu
>
> >
> > Cc: Lu Baolu <baolu.lu@linux.intel.com>
> > Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
> > ---
> > drivers/iommu/intel-svm.c | 6 ++----
> > 1 file changed, 2 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
> > index 8f42d717d8d7..1483f1845762 100644
> > --- a/drivers/iommu/intel-svm.c
> > +++ b/drivers/iommu/intel-svm.c
> > @@ -268,10 +268,9 @@ static void intel_mm_release(struct
> > mmu_notifier *mn, struct mm_struct *mm)
> > * *has* to handle gracefully without affecting other
> > processes. */
> > rcu_read_lock();
> > - list_for_each_entry_rcu(sdev, &svm->devs, list) {
> > + list_for_each_entry_rcu(sdev, &svm->devs, list)
> > intel_pasid_tear_down_entry(svm->iommu,
> > sdev->dev, svm->pasid);
> > - intel_flush_svm_range_dev(svm, sdev, 0, -1, 0);
> > - }
> > +
> > rcu_read_unlock();
> >
> > }
> > @@ -731,7 +730,6 @@ int intel_svm_unbind_mm(struct device *dev, int
> > pasid)
> > * large and has to be physically
> > contiguous. So it's
> > * hard to be as defensive as we might
> > like. */ intel_pasid_tear_down_entry(iommu, dev, svm->pasid);
> > - intel_flush_svm_range_dev(svm, sdev, 0,
> > -1, 0); kfree_rcu(sdev, rcu);
> >
> > if (list_empty(&svm->devs)) {
> >
[Jacob Pan]
next prev parent reply other threads:[~2020-03-20 16:15 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-20 4:32 [PATCH 0/3] Misc bug fixes for VT-d SVM Jacob Pan
2020-03-20 4:32 ` [PATCH 1/3] iommu/vt-d: Remove redundant IOTLB flush Jacob Pan
2020-03-20 13:45 ` Lu Baolu
2020-03-20 16:20 ` Jacob Pan [this message]
2020-03-21 1:32 ` Lu Baolu
2020-03-24 15:31 ` Jacob Pan
2020-03-25 0:48 ` Lu Baolu
2020-03-20 4:32 ` [PATCH 2/3] iommu/vt-d: Fix mm reference leak Jacob Pan
2020-03-20 13:49 ` Lu Baolu
2020-03-20 4:32 ` [PATCH 3/3] iommu/vt-d: Add build dependency on IOASID Jacob Pan
2020-03-20 13:57 ` Lu Baolu
2020-03-27 10:04 ` [PATCH 0/3] Misc bug fixes for VT-d SVM Joerg Roedel
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