* Re: [PATCH] intel-iommu: Don't be too aggressive when clearing one context entry
2017-08-28 14:16 [PATCH] intel-iommu: Don't be too aggressive when clearing one context entry Filippo Sironi
@ 2017-08-30 13:31 ` Joerg Roedel
2017-08-31 8:41 ` Sironi, Filippo
2017-08-30 15:50 ` Jacob Pan
2017-08-31 8:58 ` [PATCH v2] iommu/vt-d: " Filippo Sironi
2 siblings, 1 reply; 7+ messages in thread
From: Joerg Roedel @ 2017-08-30 13:31 UTC (permalink / raw)
To: Filippo Sironi; +Cc: iommu, linux-kernel, David Woodhouse, David Woodhouse
Hi Filippo,
please change the subject to:
iommu/vt-d: Don't be too aggressive when clearing one context entry
to follow the convention used in the iommu-tree. Another comment below.
On Mon, Aug 28, 2017 at 04:16:29PM +0200, Filippo Sironi wrote:
> static void domain_context_clear_one(struct intel_iommu *iommu, u8 bus, u8 devfn)
> {
> + unsigned long flags;
> + struct context_entry *context;
> + u16 did_old;
> +
> if (!iommu)
> return;
>
> + spin_lock_irqsave(&iommu->lock, flags);
> + context = iommu_context_addr(iommu, bus, devfn, 0);
> + if (!context) {
> + spin_unlock_irqrestore(&iommu->lock, flags);
> + return;
> + }
> + did_old = context_domain_id(context);
> + spin_unlock_irqrestore(&iommu->lock, flags);
> clear_context_table(iommu, bus, devfn);
This function is the only caller of clear_context_table(), which does
similar things (like fetching the context-entry) as you are adding
above.
So you can either make clear_context_table() return the old domain-id
so that you don't need to do it here, or you get rid of the function
entirely and add the context_clear_entry() and __iommu_flush_cache()
calls into this code-path.
Regards,
Joerg
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH] intel-iommu: Don't be too aggressive when clearing one context entry
2017-08-30 13:31 ` Joerg Roedel
@ 2017-08-31 8:41 ` Sironi, Filippo
0 siblings, 0 replies; 7+ messages in thread
From: Sironi, Filippo @ 2017-08-31 8:41 UTC (permalink / raw)
To: Joerg Roedel; +Cc: iommu, linux-kernel, Woodhouse, David, David Woodhouse
Hi Joerg,
> On 30. Aug 2017, at 15:31, Joerg Roedel <joro@8bytes.org> wrote:
>
> Hi Filippo,
>
> please change the subject to:
>
> iommu/vt-d: Don't be too aggressive when clearing one context entry
>
> to follow the convention used in the iommu-tree. Another comment below.
Will do.
> On Mon, Aug 28, 2017 at 04:16:29PM +0200, Filippo Sironi wrote:
>> static void domain_context_clear_one(struct intel_iommu *iommu, u8 bus, u8 devfn)
>> {
>> + unsigned long flags;
>> + struct context_entry *context;
>> + u16 did_old;
>> +
>> if (!iommu)
>> return;
>>
>> + spin_lock_irqsave(&iommu->lock, flags);
>> + context = iommu_context_addr(iommu, bus, devfn, 0);
>> + if (!context) {
>> + spin_unlock_irqrestore(&iommu->lock, flags);
>> + return;
>> + }
>> + did_old = context_domain_id(context);
>> + spin_unlock_irqrestore(&iommu->lock, flags);
>> clear_context_table(iommu, bus, devfn);
>
> This function is the only caller of clear_context_table(), which does
> similar things (like fetching the context-entry) as you are adding
> above.
>
> So you can either make clear_context_table() return the old domain-id
> so that you don't need to do it here, or you get rid of the function
> entirely and add the context_clear_entry() and __iommu_flush_cache()
> calls into this code-path.
>
> Regards,
>
> Joerg
I went for merging domain_context_clear_one() with context_clear_one().
Regards,
Filippo
Amazon Development Center Germany GmbH
Berlin - Dresden - Aachen
main office: Krausenstr. 38, 10117 Berlin
Geschaeftsfuehrer: Dr. Ralf Herbrich, Christian Schlaeger
Ust-ID: DE289237879
Eingetragen am Amtsgericht Charlottenburg HRB 149173 B
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] intel-iommu: Don't be too aggressive when clearing one context entry
2017-08-28 14:16 [PATCH] intel-iommu: Don't be too aggressive when clearing one context entry Filippo Sironi
2017-08-30 13:31 ` Joerg Roedel
@ 2017-08-30 15:50 ` Jacob Pan
2017-08-31 8:47 ` Sironi, Filippo
2017-08-31 8:58 ` [PATCH v2] iommu/vt-d: " Filippo Sironi
2 siblings, 1 reply; 7+ messages in thread
From: Jacob Pan @ 2017-08-30 15:50 UTC (permalink / raw)
To: Filippo Sironi via iommu
Cc: linux-kernel, Filippo Sironi, David Woodhouse, David Woodhouse,
jacob.jun.pan
On Mon, 28 Aug 2017 16:16:29 +0200
Filippo Sironi via iommu <iommu@lists.linux-foundation.org> wrote:
> Previously, we were invalidating context cache and IOTLB globally when
> clearing one context entry. This is a tad too aggressive.
> Invalidate the context cache and IOTLB for the interested device only.
>
> Signed-off-by: Filippo Sironi <sironi@amazon.de>
> Cc: David Woodhouse <dwmw@amazon.co.uk>
> Cc: David Woodhouse <dwmw2@infradead.org>
> Cc: Joerg Roedel <joro@8bytes.org>
> Cc: iommu@lists.linux-foundation.org
> Cc: linux-kernel@vger.kernel.org
> ---
> drivers/iommu/intel-iommu.c | 25 ++++++++++++++++++++++---
> 1 file changed, 22 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
> index 3e8636f1220e..4bf3e59b0929 100644
> --- a/drivers/iommu/intel-iommu.c
> +++ b/drivers/iommu/intel-iommu.c
> @@ -2351,13 +2351,32 @@ static inline int domain_pfn_mapping(struct
> dmar_domain *domain, unsigned long i
> static void domain_context_clear_one(struct intel_iommu *iommu, u8
> bus, u8 devfn) {
> + unsigned long flags;
> + struct context_entry *context;
> + u16 did_old;
> +
> if (!iommu)
> return;
>
> + spin_lock_irqsave(&iommu->lock, flags);
> + context = iommu_context_addr(iommu, bus, devfn, 0);
> + if (!context) {
> + spin_unlock_irqrestore(&iommu->lock, flags);
> + return;
> + }
perhaps check with device_context_mapped()?
> + did_old = context_domain_id(context);
> + spin_unlock_irqrestore(&iommu->lock, flags);
> clear_context_table(iommu, bus, devfn);
> - iommu->flush.flush_context(iommu, 0, 0, 0,
> - DMA_CCMD_GLOBAL_INVL);
> - iommu->flush.flush_iotlb(iommu, 0, 0, 0,
> DMA_TLB_GLOBAL_FLUSH);
> + iommu->flush.flush_context(iommu,
> + did_old,
> + (((u16)bus) << 8) | devfn,
> + DMA_CCMD_MASK_NOBIT,
> + DMA_CCMD_DEVICE_INVL);
> + iommu->flush.flush_iotlb(iommu,
> + did_old,
> + 0,
> + 0,
> + DMA_TLB_DSI_FLUSH);
> }
>
> static inline void unlink_domain_info(struct device_domain_info
> *info)
[Jacob Pan]
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH] intel-iommu: Don't be too aggressive when clearing one context entry
2017-08-30 15:50 ` Jacob Pan
@ 2017-08-31 8:47 ` Sironi, Filippo
0 siblings, 0 replies; 7+ messages in thread
From: Sironi, Filippo @ 2017-08-31 8:47 UTC (permalink / raw)
To: Jacob Pan
Cc: Filippo Sironi via iommu, linux-kernel, David Woodhouse,
Woodhouse, David
Hi Jacob,
> On 30. Aug 2017, at 17:50, Jacob Pan <jacob.jun.pan@linux.intel.com> wrote:
>
> On Mon, 28 Aug 2017 16:16:29 +0200
> Filippo Sironi via iommu <iommu@lists.linux-foundation.org> wrote:
>
>> Previously, we were invalidating context cache and IOTLB globally when
>> clearing one context entry. This is a tad too aggressive.
>> Invalidate the context cache and IOTLB for the interested device only.
>>
>> Signed-off-by: Filippo Sironi <sironi@amazon.de>
>> Cc: David Woodhouse <dwmw@amazon.co.uk>
>> Cc: David Woodhouse <dwmw2@infradead.org>
>> Cc: Joerg Roedel <joro@8bytes.org>
>> Cc: iommu@lists.linux-foundation.org
>> Cc: linux-kernel@vger.kernel.org
>> ---
>> drivers/iommu/intel-iommu.c | 25 ++++++++++++++++++++++---
>> 1 file changed, 22 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
>> index 3e8636f1220e..4bf3e59b0929 100644
>> --- a/drivers/iommu/intel-iommu.c
>> +++ b/drivers/iommu/intel-iommu.c
>> @@ -2351,13 +2351,32 @@ static inline int domain_pfn_mapping(struct
>> dmar_domain *domain, unsigned long i
>> static void domain_context_clear_one(struct intel_iommu *iommu, u8
>> bus, u8 devfn) {
>> + unsigned long flags;
>> + struct context_entry *context;
>> + u16 did_old;
>> +
>> if (!iommu)
>> return;
>>
>> + spin_lock_irqsave(&iommu->lock, flags);
>> + context = iommu_context_addr(iommu, bus, devfn, 0);
>> + if (!context) {
>> + spin_unlock_irqrestore(&iommu->lock, flags);
>> + return;
>> + }
> perhaps check with device_context_mapped()?
Using device_context_mapped() wouldn't simplify the code since it
would just tell me that at the time of check there was a context.
I would still need to lock, get the context, check if the context
is valid, do the work, and unlock.
Modifying device_context_mapped() to return the context isn't
going to work either because it may go away in the meantime since
I wouldn't hold the lock.
>> + did_old = context_domain_id(context);
>> + spin_unlock_irqrestore(&iommu->lock, flags);
>> clear_context_table(iommu, bus, devfn);
>> - iommu->flush.flush_context(iommu, 0, 0, 0,
>> - DMA_CCMD_GLOBAL_INVL);
>> - iommu->flush.flush_iotlb(iommu, 0, 0, 0,
>> DMA_TLB_GLOBAL_FLUSH);
>> + iommu->flush.flush_context(iommu,
>> + did_old,
>> + (((u16)bus) << 8) | devfn,
>> + DMA_CCMD_MASK_NOBIT,
>> + DMA_CCMD_DEVICE_INVL);
>> + iommu->flush.flush_iotlb(iommu,
>> + did_old,
>> + 0,
>> + 0,
>> + DMA_TLB_DSI_FLUSH);
>> }
>>
>> static inline void unlink_domain_info(struct device_domain_info
>> *info)
>
> [Jacob Pan]
Regards,
Filippo
Amazon Development Center Germany GmbH
Berlin - Dresden - Aachen
main office: Krausenstr. 38, 10117 Berlin
Geschaeftsfuehrer: Dr. Ralf Herbrich, Christian Schlaeger
Ust-ID: DE289237879
Eingetragen am Amtsgericht Charlottenburg HRB 149173 B
^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH v2] iommu/vt-d: Don't be too aggressive when clearing one context entry
2017-08-28 14:16 [PATCH] intel-iommu: Don't be too aggressive when clearing one context entry Filippo Sironi
2017-08-30 13:31 ` Joerg Roedel
2017-08-30 15:50 ` Jacob Pan
@ 2017-08-31 8:58 ` Filippo Sironi
2017-09-01 9:31 ` Joerg Roedel
2 siblings, 1 reply; 7+ messages in thread
From: Filippo Sironi @ 2017-08-31 8:58 UTC (permalink / raw)
To: iommu, linux-kernel
Cc: Filippo Sironi, David Woodhouse, David Woodhouse, Joerg Roedel,
Jacob Pan
Previously, we were invalidating context cache and IOTLB globally when
clearing one context entry. This is a tad too aggressive.
Invalidate the context cache and IOTLB for the interested device only.
Signed-off-by: Filippo Sironi <sironi@amazon.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: iommu@lists.linux-foundation.org
Cc: linux-kernel@vger.kernel.org
---
drivers/iommu/intel-iommu.c | 42 ++++++++++++++++++++++++------------------
1 file changed, 24 insertions(+), 18 deletions(-)
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 3e8636f1220e..1aa4ad7974b9 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -974,20 +974,6 @@ static int device_context_mapped(struct intel_iommu *iommu, u8 bus, u8 devfn)
return ret;
}
-static void clear_context_table(struct intel_iommu *iommu, u8 bus, u8 devfn)
-{
- struct context_entry *context;
- unsigned long flags;
-
- spin_lock_irqsave(&iommu->lock, flags);
- context = iommu_context_addr(iommu, bus, devfn, 0);
- if (context) {
- context_clear_entry(context);
- __iommu_flush_cache(iommu, context, sizeof(*context));
- }
- spin_unlock_irqrestore(&iommu->lock, flags);
-}
-
static void free_context_table(struct intel_iommu *iommu)
{
int i;
@@ -2351,13 +2337,33 @@ static inline int domain_pfn_mapping(struct dmar_domain *domain, unsigned long i
static void domain_context_clear_one(struct intel_iommu *iommu, u8 bus, u8 devfn)
{
+ unsigned long flags;
+ struct context_entry *context;
+ u16 did_old;
+
if (!iommu)
return;
- clear_context_table(iommu, bus, devfn);
- iommu->flush.flush_context(iommu, 0, 0, 0,
- DMA_CCMD_GLOBAL_INVL);
- iommu->flush.flush_iotlb(iommu, 0, 0, 0, DMA_TLB_GLOBAL_FLUSH);
+ spin_lock_irqsave(&iommu->lock, flags);
+ context = iommu_context_addr(iommu, bus, devfn, 0);
+ if (!context) {
+ spin_unlock_irqrestore(&iommu->lock, flags);
+ return;
+ }
+ did_old = context_domain_id(context);
+ context_clear_entry(context);
+ __iommu_flush_cache(iommu, context, sizeof(*context));
+ spin_unlock_irqrestore(&iommu->lock, flags);
+ iommu->flush.flush_context(iommu,
+ did_old,
+ (((u16)bus) << 8) | devfn,
+ DMA_CCMD_MASK_NOBIT,
+ DMA_CCMD_DEVICE_INVL);
+ iommu->flush.flush_iotlb(iommu,
+ did_old,
+ 0,
+ 0,
+ DMA_TLB_DSI_FLUSH);
}
static inline void unlink_domain_info(struct device_domain_info *info)
--
2.7.4
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH v2] iommu/vt-d: Don't be too aggressive when clearing one context entry
2017-08-31 8:58 ` [PATCH v2] iommu/vt-d: " Filippo Sironi
@ 2017-09-01 9:31 ` Joerg Roedel
0 siblings, 0 replies; 7+ messages in thread
From: Joerg Roedel @ 2017-09-01 9:31 UTC (permalink / raw)
To: Filippo Sironi
Cc: iommu, linux-kernel, David Woodhouse, David Woodhouse, Jacob Pan
On Thu, Aug 31, 2017 at 10:58:11AM +0200, Filippo Sironi wrote:
> Previously, we were invalidating context cache and IOTLB globally when
> clearing one context entry. This is a tad too aggressive.
> Invalidate the context cache and IOTLB for the interested device only.
>
> Signed-off-by: Filippo Sironi <sironi@amazon.de>
> Cc: David Woodhouse <dwmw@amazon.co.uk>
> Cc: David Woodhouse <dwmw2@infradead.org>
> Cc: Joerg Roedel <joro@8bytes.org>
> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
> Cc: iommu@lists.linux-foundation.org
> Cc: linux-kernel@vger.kernel.org
> ---
> drivers/iommu/intel-iommu.c | 42 ++++++++++++++++++++++++------------------
> 1 file changed, 24 insertions(+), 18 deletions(-)
Applied, thanks.
^ permalink raw reply [flat|nested] 7+ messages in thread