Should set the SSADE (Second Stage Access/Dirty bit Enable) bit of the
pasid entry when attaching a device to a nested domain if its parent
has already enabled dirty tracking.
Fixes: 111bf85c68f6 ("iommu/vt-d: Add helper to setup pasid nested translation")
Signed-off-by: Yi Liu <[email protected]>
---
base commit: 547ab8fc4cb04a1a6b34377dd8fad34cd2c8a8e3
---
drivers/iommu/intel/pasid.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c
index 3239cefa4c33..9be24bb762cf 100644
--- a/drivers/iommu/intel/pasid.c
+++ b/drivers/iommu/intel/pasid.c
@@ -658,6 +658,8 @@ int intel_pasid_setup_nested(struct intel_iommu *iommu, struct device *dev,
pasid_set_domain_id(pte, did);
pasid_set_address_width(pte, s2_domain->agaw);
pasid_set_page_snoop(pte, !!ecap_smpwc(iommu->ecap));
+ if (s2_domain->dirty_tracking)
+ pasid_set_ssade(pte);
pasid_set_translation_type(pte, PASID_ENTRY_PGTT_NESTED);
pasid_set_present(pte);
spin_unlock(&iommu->lock);
--
2.34.1
On 08/02/2024 09:14, Yi Liu wrote:
> Should set the SSADE (Second Stage Access/Dirty bit Enable) bit of the
> pasid entry when attaching a device to a nested domain if its parent
> has already enabled dirty tracking.
>
> Fixes: 111bf85c68f6 ("iommu/vt-d: Add helper to setup pasid nested translation")
> Signed-off-by: Yi Liu <[email protected]>
Reviewed-by: Joao Martins <[email protected]>
> ---
> base commit: 547ab8fc4cb04a1a6b34377dd8fad34cd2c8a8e3
> ---
> drivers/iommu/intel/pasid.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c
> index 3239cefa4c33..9be24bb762cf 100644
> --- a/drivers/iommu/intel/pasid.c
> +++ b/drivers/iommu/intel/pasid.c
> @@ -658,6 +658,8 @@ int intel_pasid_setup_nested(struct intel_iommu *iommu, struct device *dev,
> pasid_set_domain_id(pte, did);
> pasid_set_address_width(pte, s2_domain->agaw);
> pasid_set_page_snoop(pte, !!ecap_smpwc(iommu->ecap));
> + if (s2_domain->dirty_tracking)
> + pasid_set_ssade(pte);
> pasid_set_translation_type(pte, PASID_ENTRY_PGTT_NESTED);
> pasid_set_present(pte);
> spin_unlock(&iommu->lock);
On 2024/2/8 17:14, Yi Liu wrote:
> Should set the SSADE (Second Stage Access/Dirty bit Enable) bit of the
> pasid entry when attaching a device to a nested domain if its parent
> has already enabled dirty tracking.
>
> Fixes: 111bf85c68f6 ("iommu/vt-d: Add helper to setup pasid nested translation")
> Signed-off-by: Yi Liu <[email protected]>
> ---
> base commit: 547ab8fc4cb04a1a6b34377dd8fad34cd2c8a8e3
> ---
> drivers/iommu/intel/pasid.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c
> index 3239cefa4c33..9be24bb762cf 100644
> --- a/drivers/iommu/intel/pasid.c
> +++ b/drivers/iommu/intel/pasid.c
> @@ -658,6 +658,8 @@ int intel_pasid_setup_nested(struct intel_iommu *iommu, struct device *dev,
> pasid_set_domain_id(pte, did);
> pasid_set_address_width(pte, s2_domain->agaw);
> pasid_set_page_snoop(pte, !!ecap_smpwc(iommu->ecap));
> + if (s2_domain->dirty_tracking)
> + pasid_set_ssade(pte);
> pasid_set_translation_type(pte, PASID_ENTRY_PGTT_NESTED);
> pasid_set_present(pte);
> spin_unlock(&iommu->lock);
The same fix should also be applied to the intel_pasid_setup_second()
path. Specifically, if a second-stage domain with dirty tracking enabled
attaches to a device, the corresponding entry in the pasid table should
also have the SSADE bit set.
Best regards,
baolu
On 09/02/2024 02:40, Baolu Lu wrote:
> On 2024/2/8 17:14, Yi Liu wrote:
>> Should set the SSADE (Second Stage Access/Dirty bit Enable) bit of the
>> pasid entry when attaching a device to a nested domain if its parent
>> has already enabled dirty tracking.
>>
>> Fixes: 111bf85c68f6 ("iommu/vt-d: Add helper to setup pasid nested translation")
>> Signed-off-by: Yi Liu <[email protected]>
>> ---
>> base commit: 547ab8fc4cb04a1a6b34377dd8fad34cd2c8a8e3
>> ---
>> drivers/iommu/intel/pasid.c | 2 ++
>> 1 file changed, 2 insertions(+)
>>
>> diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c
>> index 3239cefa4c33..9be24bb762cf 100644
>> --- a/drivers/iommu/intel/pasid.c
>> +++ b/drivers/iommu/intel/pasid.c
>> @@ -658,6 +658,8 @@ int intel_pasid_setup_nested(struct intel_iommu *iommu,
>> struct device *dev,
>> pasid_set_domain_id(pte, did);
>> pasid_set_address_width(pte, s2_domain->agaw);
>> pasid_set_page_snoop(pte, !!ecap_smpwc(iommu->ecap));
>> + if (s2_domain->dirty_tracking)
>> + pasid_set_ssade(pte);
>> pasid_set_translation_type(pte, PASID_ENTRY_PGTT_NESTED);
>> pasid_set_present(pte);
>> spin_unlock(&iommu->lock);
>
> The same fix should also be applied to the intel_pasid_setup_second()
> path. Specifically, if a second-stage domain with dirty tracking enabled
> attaches to a device, the corresponding entry in the pasid table should
> also have the SSADE bit set.
>
I think that's already done, see below.
/*
* Set up the scalable mode pasid entry for second only translation type.
*/
int intel_pasid_setup_second_level(struct intel_iommu *iommu,
struct dmar_domain *domain,
struct device *dev, u32 pasid)
{
(...)
pasid_clear_entry(pte);
pasid_set_domain_id(pte, did);
pasid_set_slptr(pte, pgd_val);
pasid_set_address_width(pte, agaw);
pasid_set_translation_type(pte, PASID_ENTRY_PGTT_SL_ONLY);
pasid_set_fault_enable(pte);
pasid_set_page_snoop(pte, !!ecap_smpwc(iommu->ecap));
if (domain->dirty_tracking)
pasid_set_ssade(pte);
(...)
}
On 08/02/2024 10:31, Joao Martins wrote:
> On 08/02/2024 09:14, Yi Liu wrote:
>> Should set the SSADE (Second Stage Access/Dirty bit Enable) bit of the
>> pasid entry when attaching a device to a nested domain if its parent
>> has already enabled dirty tracking.
>>
>> Fixes: 111bf85c68f6 ("iommu/vt-d: Add helper to setup pasid nested translation")
>> Signed-off-by: Yi Liu <[email protected]>
>
> Reviewed-by: Joao Martins <[email protected]>
>
On a second thought, while the patch looks fine if this is what we wanna do,
just a quick clarification on the why (that's also applicable to the last patch
of your other series[0]). I am sure I am missing something :)
Shouldn't the nested domain be subdued to whatever features guest idea of
ecap/cap instead of host's view? Or is this because guest first-stage page table
on Intel is supposed to be always-enabled dirty tracking (per SDM) ? If it's the
latter, it probably should be sprinkled in the commit message(s).
[0] https://lore.kernel.org/linux-iommu/[email protected]/
>> ---
>> base commit: 547ab8fc4cb04a1a6b34377dd8fad34cd2c8a8e3
>> ---
>> drivers/iommu/intel/pasid.c | 2 ++
>> 1 file changed, 2 insertions(+)
>>
>> diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c
>> index 3239cefa4c33..9be24bb762cf 100644
>> --- a/drivers/iommu/intel/pasid.c
>> +++ b/drivers/iommu/intel/pasid.c
>> @@ -658,6 +658,8 @@ int intel_pasid_setup_nested(struct intel_iommu *iommu, struct device *dev,
>> pasid_set_domain_id(pte, did);
>> pasid_set_address_width(pte, s2_domain->agaw);
>> pasid_set_page_snoop(pte, !!ecap_smpwc(iommu->ecap));
>> + if (s2_domain->dirty_tracking)
>> + pasid_set_ssade(pte);
>> pasid_set_translation_type(pte, PASID_ENTRY_PGTT_NESTED);
>> pasid_set_present(pte);
>> spin_unlock(&iommu->lock);
>
> From: Joao Martins <[email protected]>
> Sent: Friday, February 9, 2024 6:36 PM
>
> On 08/02/2024 10:31, Joao Martins wrote:
> > On 08/02/2024 09:14, Yi Liu wrote:
> >> Should set the SSADE (Second Stage Access/Dirty bit Enable) bit of the
> >> pasid entry when attaching a device to a nested domain if its parent
> >> has already enabled dirty tracking.
> >>
> >> Fixes: 111bf85c68f6 ("iommu/vt-d: Add helper to setup pasid nested
> translation")
> >> Signed-off-by: Yi Liu <[email protected]>
> >
> > Reviewed-by: Joao Martins <[email protected]>
> >
> On a second thought, while the patch looks fine if this is what we wanna do,
> just a quick clarification on the why (that's also applicable to the last patch
> of your other series[0]). I am sure I am missing something :)
>
> Shouldn't the nested domain be subdued to whatever features guest idea of
> ecap/cap instead of host's view? Or is this because guest first-stage page
> table
> on Intel is supposed to be always-enabled dirty tracking (per SDM) ? If it's the
> latter, it probably should be sprinkled in the commit message(s).
>
> [0] https://lore.kernel.org/linux-iommu/20240208082307.15759-9-
> [email protected]/
>
first-stage dirty tracking is always enabled. but the real point here is
that the host has enabled dirty-tracking in second-stage so when
a device is attached to a nested domain on top of that second-stage
we should set SSADE in the pasid entry for that device.
even if there is a guest ecap/cap for first-stage dirty tracking that
shouldn't affect the host setting for second-stage which is invisible
to the guest.