Re: [PATCH v5 7/8] iommu/amd: Don't update domain info to dte entry at iommu init stage

[Baoquan He]

On 09/21/16 at 06:26pm, Baoquan He wrote:
> On 09/20/16 at 02:50pm, Joerg Roedel wrote:
> > On Thu, Sep 15, 2016 at 11:03:25PM +0800, Baoquan He wrote:
> > > AMD iommu creates protection domain and assign each device to it during
> > > iommu driver initialization stage. This happened just after system pci
> > > bus scanning stage, and much earlier than device driver init stage. So
> > > at this time if in kdump kernel the domain info, especially pte_root,
> > > can't be updated to dte entry. We should wait until device driver init
> > > stage.
> > > 
> > > Signed-off-by: Baoquan He 
> > > ---
> > >  drivers/iommu/amd_iommu.c | 18 ++
> > >  1 file changed, 18 insertions(+)
> > > 
> > > diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
> > > index fcb69ff..6c37300 100644
> > > --- a/drivers/iommu/amd_iommu.c
> > > +++ b/drivers/iommu/amd_iommu.c
> > > @@ -137,6 +137,7 @@ struct iommu_dev_data {
> > >   bool pri_tlp; /* PASID TLB required for
> > >PPR completions */
> > >   u32 errata;   /* Bitmap for errata to apply */
> > > + bool domain_updated;
> > >  };
> > >  
> > >  /*
> > > @@ -1708,6 +1709,15 @@ static void set_dte_entry(u16 devid, struct 
> > > protection_domain *domain, bool ats)
> > >  {
> > >   u64 pte_root = 0;
> > >   u64 flags = 0;
> > > + struct iommu_dev_data *dev_data;
> > > + struct amd_iommu *iommu = amd_iommu_rlookup_table[devid];
> > > +
> > > + dev_data = find_dev_data(devid);
> > > +if (!dev_data)
> > > +return;
> > > +
> > > + if (translation_pre_enabled(iommu) && !dev_data->domain_updated)
> > > + return;
> > >  
> > >   if (domain->mode != PAGE_MODE_NONE)
> > >   pte_root = virt_to_phys(domain->pt_root);
> > > @@ -1756,6 +1766,14 @@ static void set_dte_entry(u16 devid, struct 
> > > protection_domain *domain, bool ats)
> > >  
> > >  static void clear_dte_entry(u16 devid)
> > >  {
> > > + struct iommu_dev_data *dev_data;
> > > + struct amd_iommu *iommu = amd_iommu_rlookup_table[devid];
> > > +
> > > + dev_data = find_dev_data(devid);
> > > +if (!dev_data)
> > > +return;
> > > + if (translation_pre_enabled(iommu) && !dev_data->domain_updated)
> > > + return;
> > 
> > This should be moved to do_attach/do_detach. There you also already have
> > the dev_data you need here.
> 
> For amd-vi v1, checking in do_attach/do_detach is enough. But for v2
> amd_iommu_domain_direct_map and amd_iommu_domain_enable_v2 also call it
Here I means amd_iommu_domain_direct_map and amd_iommu_domain_enable_v2
will call set_dte_entry to change pte_root setting.

> to install pte_root into dev table. So finally, I move them into these
> two lowest level functions to prevent any pte_root changing during iommu
> init stage. It involves the least code change.
> 
> > 
> > >   /* remove entry from the device table seen by the hardware */
> > >   amd_iommu_dev_table[devid].data[0]  = DTE_FLAG_V | DTE_FLAG_TV;
> > >   amd_iommu_dev_table[devid].data[1] &= DTE_FLAG_MASK;
> > > -- 
> > > 2.5.5
> > > 

Re: [PATCH v5 7/8] iommu/amd: Don't update domain info to dte entry at iommu init stage

[Baoquan He]

On 09/21/16 at 06:26pm, Baoquan He wrote:
> On 09/20/16 at 02:50pm, Joerg Roedel wrote:
> > On Thu, Sep 15, 2016 at 11:03:25PM +0800, Baoquan He wrote:
> > > AMD iommu creates protection domain and assign each device to it during
> > > iommu driver initialization stage. This happened just after system pci
> > > bus scanning stage, and much earlier than device driver init stage. So
> > > at this time if in kdump kernel the domain info, especially pte_root,
> > > can't be updated to dte entry. We should wait until device driver init
> > > stage.
> > > 
> > > Signed-off-by: Baoquan He 
> > > ---
> > >  drivers/iommu/amd_iommu.c | 18 ++
> > >  1 file changed, 18 insertions(+)
> > > 
> > > diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
> > > index fcb69ff..6c37300 100644
> > > --- a/drivers/iommu/amd_iommu.c
> > > +++ b/drivers/iommu/amd_iommu.c
> > > @@ -137,6 +137,7 @@ struct iommu_dev_data {
> > >   bool pri_tlp; /* PASID TLB required for
> > >PPR completions */
> > >   u32 errata;   /* Bitmap for errata to apply */
> > > + bool domain_updated;
> > >  };
> > >  
> > >  /*
> > > @@ -1708,6 +1709,15 @@ static void set_dte_entry(u16 devid, struct 
> > > protection_domain *domain, bool ats)
> > >  {
> > >   u64 pte_root = 0;
> > >   u64 flags = 0;
> > > + struct iommu_dev_data *dev_data;
> > > + struct amd_iommu *iommu = amd_iommu_rlookup_table[devid];
> > > +
> > > + dev_data = find_dev_data(devid);
> > > +if (!dev_data)
> > > +return;
> > > +
> > > + if (translation_pre_enabled(iommu) && !dev_data->domain_updated)
> > > + return;
> > >  
> > >   if (domain->mode != PAGE_MODE_NONE)
> > >   pte_root = virt_to_phys(domain->pt_root);
> > > @@ -1756,6 +1766,14 @@ static void set_dte_entry(u16 devid, struct 
> > > protection_domain *domain, bool ats)
> > >  
> > >  static void clear_dte_entry(u16 devid)
> > >  {
> > > + struct iommu_dev_data *dev_data;
> > > + struct amd_iommu *iommu = amd_iommu_rlookup_table[devid];
> > > +
> > > + dev_data = find_dev_data(devid);
> > > +if (!dev_data)
> > > +return;
> > > + if (translation_pre_enabled(iommu) && !dev_data->domain_updated)
> > > + return;
> > 
> > This should be moved to do_attach/do_detach. There you also already have
> > the dev_data you need here.
> 
> For amd-vi v1, checking in do_attach/do_detach is enough. But for v2
> amd_iommu_domain_direct_map and amd_iommu_domain_enable_v2 also call it
Here I means amd_iommu_domain_direct_map and amd_iommu_domain_enable_v2
will call set_dte_entry to change pte_root setting.

> to install pte_root into dev table. So finally, I move them into these
> two lowest level functions to prevent any pte_root changing during iommu
> init stage. It involves the least code change.
> 
> > 
> > >   /* remove entry from the device table seen by the hardware */
> > >   amd_iommu_dev_table[devid].data[0]  = DTE_FLAG_V | DTE_FLAG_TV;
> > >   amd_iommu_dev_table[devid].data[1] &= DTE_FLAG_MASK;
> > > -- 
> > > 2.5.5
> > > 

Re: [PATCH v5 7/8] iommu/amd: Don't update domain info to dte entry at iommu init stage

[Baoquan He]

On 09/20/16 at 02:50pm, Joerg Roedel wrote:
> On Thu, Sep 15, 2016 at 11:03:25PM +0800, Baoquan He wrote:
> > AMD iommu creates protection domain and assign each device to it during
> > iommu driver initialization stage. This happened just after system pci
> > bus scanning stage, and much earlier than device driver init stage. So
> > at this time if in kdump kernel the domain info, especially pte_root,
> > can't be updated to dte entry. We should wait until device driver init
> > stage.
> > 
> > Signed-off-by: Baoquan He 
> > ---
> >  drivers/iommu/amd_iommu.c | 18 ++
> >  1 file changed, 18 insertions(+)
> > 
> > diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
> > index fcb69ff..6c37300 100644
> > --- a/drivers/iommu/amd_iommu.c
> > +++ b/drivers/iommu/amd_iommu.c
> > @@ -137,6 +137,7 @@ struct iommu_dev_data {
> > bool pri_tlp; /* PASID TLB required for
> >  PPR completions */
> > u32 errata;   /* Bitmap for errata to apply */
> > +   bool domain_updated;
> >  };
> >  
> >  /*
> > @@ -1708,6 +1709,15 @@ static void set_dte_entry(u16 devid, struct 
> > protection_domain *domain, bool ats)
> >  {
> > u64 pte_root = 0;
> > u64 flags = 0;
> > +   struct iommu_dev_data *dev_data;
> > +   struct amd_iommu *iommu = amd_iommu_rlookup_table[devid];
> > +
> > +   dev_data = find_dev_data(devid);
> > +if (!dev_data)
> > +return;
> > +
> > +   if (translation_pre_enabled(iommu) && !dev_data->domain_updated)
> > +   return;
> >  
> > if (domain->mode != PAGE_MODE_NONE)
> > pte_root = virt_to_phys(domain->pt_root);
> > @@ -1756,6 +1766,14 @@ static void set_dte_entry(u16 devid, struct 
> > protection_domain *domain, bool ats)
> >  
> >  static void clear_dte_entry(u16 devid)
> >  {
> > +   struct iommu_dev_data *dev_data;
> > +   struct amd_iommu *iommu = amd_iommu_rlookup_table[devid];
> > +
> > +   dev_data = find_dev_data(devid);
> > +if (!dev_data)
> > +return;
> > +   if (translation_pre_enabled(iommu) && !dev_data->domain_updated)
> > +   return;
> 
> This should be moved to do_attach/do_detach. There you also already have
> the dev_data you need here.

For amd-vi v1, checking in do_attach/do_detach is enough. But for v2
amd_iommu_domain_direct_map and amd_iommu_domain_enable_v2 also call it
to install pte_root into dev table. So finally, I move them into these
two lowest level functions to prevent any pte_root changing during iommu
init stage. It involves the least code change.

> 
> > /* remove entry from the device table seen by the hardware */
> > amd_iommu_dev_table[devid].data[0]  = DTE_FLAG_V | DTE_FLAG_TV;
> > amd_iommu_dev_table[devid].data[1] &= DTE_FLAG_MASK;
> > -- 
> > 2.5.5
> > 

Re: [PATCH v5 7/8] iommu/amd: Don't update domain info to dte entry at iommu init stage

[Baoquan He]

On 09/20/16 at 02:50pm, Joerg Roedel wrote:
> On Thu, Sep 15, 2016 at 11:03:25PM +0800, Baoquan He wrote:
> > AMD iommu creates protection domain and assign each device to it during
> > iommu driver initialization stage. This happened just after system pci
> > bus scanning stage, and much earlier than device driver init stage. So
> > at this time if in kdump kernel the domain info, especially pte_root,
> > can't be updated to dte entry. We should wait until device driver init
> > stage.
> > 
> > Signed-off-by: Baoquan He 
> > ---
> >  drivers/iommu/amd_iommu.c | 18 ++
> >  1 file changed, 18 insertions(+)
> > 
> > diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
> > index fcb69ff..6c37300 100644
> > --- a/drivers/iommu/amd_iommu.c
> > +++ b/drivers/iommu/amd_iommu.c
> > @@ -137,6 +137,7 @@ struct iommu_dev_data {
> > bool pri_tlp; /* PASID TLB required for
> >  PPR completions */
> > u32 errata;   /* Bitmap for errata to apply */
> > +   bool domain_updated;
> >  };
> >  
> >  /*
> > @@ -1708,6 +1709,15 @@ static void set_dte_entry(u16 devid, struct 
> > protection_domain *domain, bool ats)
> >  {
> > u64 pte_root = 0;
> > u64 flags = 0;
> > +   struct iommu_dev_data *dev_data;
> > +   struct amd_iommu *iommu = amd_iommu_rlookup_table[devid];
> > +
> > +   dev_data = find_dev_data(devid);
> > +if (!dev_data)
> > +return;
> > +
> > +   if (translation_pre_enabled(iommu) && !dev_data->domain_updated)
> > +   return;
> >  
> > if (domain->mode != PAGE_MODE_NONE)
> > pte_root = virt_to_phys(domain->pt_root);
> > @@ -1756,6 +1766,14 @@ static void set_dte_entry(u16 devid, struct 
> > protection_domain *domain, bool ats)
> >  
> >  static void clear_dte_entry(u16 devid)
> >  {
> > +   struct iommu_dev_data *dev_data;
> > +   struct amd_iommu *iommu = amd_iommu_rlookup_table[devid];
> > +
> > +   dev_data = find_dev_data(devid);
> > +if (!dev_data)
> > +return;
> > +   if (translation_pre_enabled(iommu) && !dev_data->domain_updated)
> > +   return;
> 
> This should be moved to do_attach/do_detach. There you also already have
> the dev_data you need here.

For amd-vi v1, checking in do_attach/do_detach is enough. But for v2
amd_iommu_domain_direct_map and amd_iommu_domain_enable_v2 also call it
to install pte_root into dev table. So finally, I move them into these
two lowest level functions to prevent any pte_root changing during iommu
init stage. It involves the least code change.

> 
> > /* remove entry from the device table seen by the hardware */
> > amd_iommu_dev_table[devid].data[0]  = DTE_FLAG_V | DTE_FLAG_TV;
> > amd_iommu_dev_table[devid].data[1] &= DTE_FLAG_MASK;
> > -- 
> > 2.5.5
> > 

Re: [PATCH v5 7/8] iommu/amd: Don't update domain info to dte entry at iommu init stage

[Joerg Roedel]

On Thu, Sep 15, 2016 at 11:03:25PM +0800, Baoquan He wrote:
> AMD iommu creates protection domain and assign each device to it during
> iommu driver initialization stage. This happened just after system pci
> bus scanning stage, and much earlier than device driver init stage. So
> at this time if in kdump kernel the domain info, especially pte_root,
> can't be updated to dte entry. We should wait until device driver init
> stage.
> 
> Signed-off-by: Baoquan He 
> ---
>  drivers/iommu/amd_iommu.c | 18 ++
>  1 file changed, 18 insertions(+)
> 
> diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
> index fcb69ff..6c37300 100644
> --- a/drivers/iommu/amd_iommu.c
> +++ b/drivers/iommu/amd_iommu.c
> @@ -137,6 +137,7 @@ struct iommu_dev_data {
>   bool pri_tlp; /* PASID TLB required for
>PPR completions */
>   u32 errata;   /* Bitmap for errata to apply */
> + bool domain_updated;
>  };
>  
>  /*
> @@ -1708,6 +1709,15 @@ static void set_dte_entry(u16 devid, struct 
> protection_domain *domain, bool ats)
>  {
>   u64 pte_root = 0;
>   u64 flags = 0;
> + struct iommu_dev_data *dev_data;
> + struct amd_iommu *iommu = amd_iommu_rlookup_table[devid];
> +
> + dev_data = find_dev_data(devid);
> +if (!dev_data)
> +return;
> +
> + if (translation_pre_enabled(iommu) && !dev_data->domain_updated)
> + return;
>  
>   if (domain->mode != PAGE_MODE_NONE)
>   pte_root = virt_to_phys(domain->pt_root);
> @@ -1756,6 +1766,14 @@ static void set_dte_entry(u16 devid, struct 
> protection_domain *domain, bool ats)
>  
>  static void clear_dte_entry(u16 devid)
>  {
> + struct iommu_dev_data *dev_data;
> + struct amd_iommu *iommu = amd_iommu_rlookup_table[devid];
> +
> + dev_data = find_dev_data(devid);
> +if (!dev_data)
> +return;
> + if (translation_pre_enabled(iommu) && !dev_data->domain_updated)
> + return;

This should be moved to do_attach/do_detach. There you also already have
the dev_data you need here.

>   /* remove entry from the device table seen by the hardware */
>   amd_iommu_dev_table[devid].data[0]  = DTE_FLAG_V | DTE_FLAG_TV;
>   amd_iommu_dev_table[devid].data[1] &= DTE_FLAG_MASK;
> -- 
> 2.5.5
> 

Re: [PATCH v5 7/8] iommu/amd: Don't update domain info to dte entry at iommu init stage

[Joerg Roedel]

On Thu, Sep 15, 2016 at 11:03:25PM +0800, Baoquan He wrote:
> AMD iommu creates protection domain and assign each device to it during
> iommu driver initialization stage. This happened just after system pci
> bus scanning stage, and much earlier than device driver init stage. So
> at this time if in kdump kernel the domain info, especially pte_root,
> can't be updated to dte entry. We should wait until device driver init
> stage.
> 
> Signed-off-by: Baoquan He 
> ---
>  drivers/iommu/amd_iommu.c | 18 ++
>  1 file changed, 18 insertions(+)
> 
> diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
> index fcb69ff..6c37300 100644
> --- a/drivers/iommu/amd_iommu.c
> +++ b/drivers/iommu/amd_iommu.c
> @@ -137,6 +137,7 @@ struct iommu_dev_data {
>   bool pri_tlp; /* PASID TLB required for
>PPR completions */
>   u32 errata;   /* Bitmap for errata to apply */
> + bool domain_updated;
>  };
>  
>  /*
> @@ -1708,6 +1709,15 @@ static void set_dte_entry(u16 devid, struct 
> protection_domain *domain, bool ats)
>  {
>   u64 pte_root = 0;
>   u64 flags = 0;
> + struct iommu_dev_data *dev_data;
> + struct amd_iommu *iommu = amd_iommu_rlookup_table[devid];
> +
> + dev_data = find_dev_data(devid);
> +if (!dev_data)
> +return;
> +
> + if (translation_pre_enabled(iommu) && !dev_data->domain_updated)
> + return;
>  
>   if (domain->mode != PAGE_MODE_NONE)
>   pte_root = virt_to_phys(domain->pt_root);
> @@ -1756,6 +1766,14 @@ static void set_dte_entry(u16 devid, struct 
> protection_domain *domain, bool ats)
>  
>  static void clear_dte_entry(u16 devid)
>  {
> + struct iommu_dev_data *dev_data;
> + struct amd_iommu *iommu = amd_iommu_rlookup_table[devid];
> +
> + dev_data = find_dev_data(devid);
> +if (!dev_data)
> +return;
> + if (translation_pre_enabled(iommu) && !dev_data->domain_updated)
> + return;

This should be moved to do_attach/do_detach. There you also already have
the dev_data you need here.

>   /* remove entry from the device table seen by the hardware */
>   amd_iommu_dev_table[devid].data[0]  = DTE_FLAG_V | DTE_FLAG_TV;
>   amd_iommu_dev_table[devid].data[1] &= DTE_FLAG_MASK;
> -- 
> 2.5.5
>