Re: [PATCH 1/3] iommu/vt-d: Remove redundant IOTLB flush
On 2020/3/24 23:31, Jacob Pan wrote: On Sat, 21 Mar 2020 09:32:45 +0800 Lu Baolu wrote: On 2020/3/21 0:20, Jacob Pan wrote: On Fri, 20 Mar 2020 21:45:26 +0800 Lu Baolu 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); But devtlb_invalidation_with_pasid() doesn't do the right thing, it flushes the device tlb, instead of pasid-based device tlb. Hmm, you are right. But the function name is misleading, pasid argument is not used, is there a reason why? This is used for PASID based device IOTLB flush, right? Yes. I will fix and put your patch after it. Best regards, baolu ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
Re: [PATCH 1/3] iommu/vt-d: Remove redundant IOTLB flush
On Sat, 21 Mar 2020 09:32:45 +0800
Lu Baolu wrote:
> On 2020/3/21 0:20, Jacob Pan wrote:
> > On Fri, 20 Mar 2020 21:45:26 +0800
> > Lu Baolu 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);
> >
>
> But devtlb_invalidation_with_pasid() doesn't do the right thing, it
> flushes the device tlb, instead of pasid-based device tlb.
>
Hmm, you are right. But the function name is misleading, pasid argument
is not used, is there a reason why?
This is used for PASID based device IOTLB flush, right?
> static void
> devtlb_invalidation_with_pasid(struct intel_iommu *iommu,
> struct device *dev, int pasid)
> {
> struct device_domain_info *info;
> u16 sid, qdep, pfsid;
>
> info = dev->archdata.iommu;
> if (!info || !info->ats_enabled)
> return;
>
> sid = info->bus << 8 | info->devfn;
> qdep = info->ats_qdep;
> pfsid = info->pfsid;
>
> qi_flush_dev_iotlb(iommu, sid, pfsid, qdep, 0, 64 -
> VTD_PAGE_SHIFT);
> }
>
> Best regards,
> baolu
>
> >> Best regards,
> >> baolu
> >>
> >>>
> >>> Cc: Lu Baolu
> >>> Signed-off-by: Jacob Pan
> >>> ---
> >>>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, >devs, list) {
> >>> + list_for_each_entry_rcu(sdev, >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(>devs)) {
> >>>
> >
> > [Jacob Pan]
> >
[Jacob Pan]
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Re: [PATCH 1/3] iommu/vt-d: Remove redundant IOTLB flush
On 2020/3/21 0:20, Jacob Pan wrote:
On Fri, 20 Mar 2020 21:45:26 +0800
Lu Baolu 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);
But devtlb_invalidation_with_pasid() doesn't do the right thing, it
flushes the device tlb, instead of pasid-based device tlb.
static void
devtlb_invalidation_with_pasid(struct intel_iommu *iommu,
struct device *dev, int pasid)
{
struct device_domain_info *info;
u16 sid, qdep, pfsid;
info = dev->archdata.iommu;
if (!info || !info->ats_enabled)
return;
sid = info->bus << 8 | info->devfn;
qdep = info->ats_qdep;
pfsid = info->pfsid;
qi_flush_dev_iotlb(iommu, sid, pfsid, qdep, 0, 64 -
VTD_PAGE_SHIFT);
}
Best regards,
baolu
Best regards,
baolu
Cc: Lu Baolu
Signed-off-by: Jacob Pan
---
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, >devs, list) {
+ list_for_each_entry_rcu(sdev, >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(>devs)) {
[Jacob Pan]
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Re: [PATCH 1/3] iommu/vt-d: Remove redundant IOTLB flush
On Fri, 20 Mar 2020 21:45:26 +0800
Lu Baolu 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
> > Signed-off-by: Jacob Pan
> > ---
> > 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, >devs, list) {
> > + list_for_each_entry_rcu(sdev, >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(>devs)) {
> >
[Jacob Pan]
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Re: [PATCH 1/3] iommu/vt-d: Remove redundant IOTLB flush
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?
Best regards,
baolu
Cc: Lu Baolu
Signed-off-by: Jacob Pan
---
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, >devs, list) {
+ list_for_each_entry_rcu(sdev, >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(>devs)) {
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[PATCH 1/3] iommu/vt-d: Remove redundant IOTLB flush
IOTLB flush already included in the PASID tear down process. There
is no need to flush again.
Cc: Lu Baolu
Signed-off-by: Jacob Pan
---
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, >devs, list) {
+ list_for_each_entry_rcu(sdev, >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(>devs)) {
--
2.7.4
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