| Message ID | 20210114013003.297050-2-baolu.lu@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add platform check for subdevice irq domain | expand |
On Thu, Jan 14, 2021 at 09:30:02AM +0800, Lu Baolu wrote: > Some vendor IOMMU drivers are able to declare that it is running in a VM > context. This is very valuable for the features that only want to be > supported on bare metal. Add a capability bit so that it could be used. And how is it used? Who and how will set it? > > Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> > --- > drivers/iommu/intel/iommu.c | 20 ++++++++++++++++++++ > drivers/iommu/virtio-iommu.c | 9 +++++++++ > include/linux/iommu.h | 1 + > 3 files changed, 30 insertions(+) > > diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c > index cb205a04fe4c..8eb022d0e8aa 100644 > --- a/drivers/iommu/intel/iommu.c > +++ b/drivers/iommu/intel/iommu.c > @@ -5738,12 +5738,32 @@ static inline bool nested_mode_support(void) > return ret; > } > > +static inline bool caching_mode_enabled(void) > +{ Kernel coding style is not in favour of inline functions in *.c files. > + struct dmar_drhd_unit *drhd; > + struct intel_iommu *iommu; > + bool ret = false; > + > + rcu_read_lock(); > + for_each_active_iommu(iommu, drhd) { > + if (cap_caching_mode(iommu->cap)) { > + ret = true; > + break; > + } > + } > + rcu_read_unlock(); > + > + return ret; > +} > + > static bool intel_iommu_capable(enum iommu_cap cap) > { > if (cap == IOMMU_CAP_CACHE_COHERENCY) > return domain_update_iommu_snooping(NULL) == 1; > if (cap == IOMMU_CAP_INTR_REMAP) > return irq_remapping_enabled == 1; > + if (cap == IOMMU_CAP_VIOMMU) > + return caching_mode_enabled(); > > return false; > } > diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c > index 2bfdd5734844..719793e103db 100644 > --- a/drivers/iommu/virtio-iommu.c > +++ b/drivers/iommu/virtio-iommu.c > @@ -931,7 +931,16 @@ static int viommu_of_xlate(struct device *dev, struct of_phandle_args *args) > return iommu_fwspec_add_ids(dev, args->args, 1); > } > > +static bool viommu_capable(enum iommu_cap cap) > +{ > + if (cap == IOMMU_CAP_VIOMMU) > + return true; > + > + return false; > +} > + > static struct iommu_ops viommu_ops = { > + .capable = viommu_capable, > .domain_alloc = viommu_domain_alloc, > .domain_free = viommu_domain_free, > .attach_dev = viommu_attach_dev, > diff --git a/include/linux/iommu.h b/include/linux/iommu.h > index b95a6f8db6ff..1d24be667a03 100644 > --- a/include/linux/iommu.h > +++ b/include/linux/iommu.h > @@ -94,6 +94,7 @@ enum iommu_cap { > transactions */ > IOMMU_CAP_INTR_REMAP, /* IOMMU supports interrupt isolation */ > IOMMU_CAP_NOEXEC, /* IOMMU_NOEXEC flag */ > + IOMMU_CAP_VIOMMU, /* IOMMU can declar running in a VM */ > }; > > /* > -- > 2.25.1 >
Hi Leon, On 1/14/21 9:26 PM, Leon Romanovsky wrote: > On Thu, Jan 14, 2021 at 09:30:02AM +0800, Lu Baolu wrote: >> Some vendor IOMMU drivers are able to declare that it is running in a VM >> context. This is very valuable for the features that only want to be >> supported on bare metal. Add a capability bit so that it could be used. > > And how is it used? Who and how will set it? Use the existing iommu_capable(). I should add more descriptions about who and how to use it. > >> >> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> >> --- >> drivers/iommu/intel/iommu.c | 20 ++++++++++++++++++++ >> drivers/iommu/virtio-iommu.c | 9 +++++++++ >> include/linux/iommu.h | 1 + >> 3 files changed, 30 insertions(+) >> >> diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c >> index cb205a04fe4c..8eb022d0e8aa 100644 >> --- a/drivers/iommu/intel/iommu.c >> +++ b/drivers/iommu/intel/iommu.c >> @@ -5738,12 +5738,32 @@ static inline bool nested_mode_support(void) >> return ret; >> } >> >> +static inline bool caching_mode_enabled(void) >> +{ > > Kernel coding style is not in favour of inline functions in *.c files. Yes, agreed. Best regards, baolu > >> + struct dmar_drhd_unit *drhd; >> + struct intel_iommu *iommu; >> + bool ret = false; >> + >> + rcu_read_lock(); >> + for_each_active_iommu(iommu, drhd) { >> + if (cap_caching_mode(iommu->cap)) { >> + ret = true; >> + break; >> + } >> + } >> + rcu_read_unlock(); >> + >> + return ret; >> +} >> + >> static bool intel_iommu_capable(enum iommu_cap cap) >> { >> if (cap == IOMMU_CAP_CACHE_COHERENCY) >> return domain_update_iommu_snooping(NULL) == 1; >> if (cap == IOMMU_CAP_INTR_REMAP) >> return irq_remapping_enabled == 1; >> + if (cap == IOMMU_CAP_VIOMMU) >> + return caching_mode_enabled(); >> >> return false; >> } >> diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c >> index 2bfdd5734844..719793e103db 100644 >> --- a/drivers/iommu/virtio-iommu.c >> +++ b/drivers/iommu/virtio-iommu.c >> @@ -931,7 +931,16 @@ static int viommu_of_xlate(struct device *dev, struct of_phandle_args *args) >> return iommu_fwspec_add_ids(dev, args->args, 1); >> } >> >> +static bool viommu_capable(enum iommu_cap cap) >> +{ >> + if (cap == IOMMU_CAP_VIOMMU) >> + return true; >> + >> + return false; >> +} >> + >> static struct iommu_ops viommu_ops = { >> + .capable = viommu_capable, >> .domain_alloc = viommu_domain_alloc, >> .domain_free = viommu_domain_free, >> .attach_dev = viommu_attach_dev, >> diff --git a/include/linux/iommu.h b/include/linux/iommu.h >> index b95a6f8db6ff..1d24be667a03 100644 >> --- a/include/linux/iommu.h >> +++ b/include/linux/iommu.h >> @@ -94,6 +94,7 @@ enum iommu_cap { >> transactions */ >> IOMMU_CAP_INTR_REMAP, /* IOMMU supports interrupt isolation */ >> IOMMU_CAP_NOEXEC, /* IOMMU_NOEXEC flag */ >> + IOMMU_CAP_VIOMMU, /* IOMMU can declar running in a VM */ >> }; >> >> /* >> -- >> 2.25.1 >>
On 2021/1/14 上午9:30, Lu Baolu wrote: > Some vendor IOMMU drivers are able to declare that it is running in a VM > context. This is very valuable for the features that only want to be > supported on bare metal. Add a capability bit so that it could be used. > > Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> > --- > drivers/iommu/intel/iommu.c | 20 ++++++++++++++++++++ > drivers/iommu/virtio-iommu.c | 9 +++++++++ > include/linux/iommu.h | 1 + > 3 files changed, 30 insertions(+) > > diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c > index cb205a04fe4c..8eb022d0e8aa 100644 > --- a/drivers/iommu/intel/iommu.c > +++ b/drivers/iommu/intel/iommu.c > @@ -5738,12 +5738,32 @@ static inline bool nested_mode_support(void) > return ret; > } > > +static inline bool caching_mode_enabled(void) > +{ > + struct dmar_drhd_unit *drhd; > + struct intel_iommu *iommu; > + bool ret = false; > + > + rcu_read_lock(); > + for_each_active_iommu(iommu, drhd) { > + if (cap_caching_mode(iommu->cap)) { > + ret = true; > + break; > + } > + } > + rcu_read_unlock(); > + > + return ret; > +} > + > static bool intel_iommu_capable(enum iommu_cap cap) > { > if (cap == IOMMU_CAP_CACHE_COHERENCY) > return domain_update_iommu_snooping(NULL) == 1; > if (cap == IOMMU_CAP_INTR_REMAP) > return irq_remapping_enabled == 1; > + if (cap == IOMMU_CAP_VIOMMU) > + return caching_mode_enabled(); This part I don't understand. Does it mean Intel IOMMU can't be used in VM without caching mode? Thanks > > return false; > } > diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c > index 2bfdd5734844..719793e103db 100644 > --- a/drivers/iommu/virtio-iommu.c > +++ b/drivers/iommu/virtio-iommu.c > @@ -931,7 +931,16 @@ static int viommu_of_xlate(struct device *dev, struct of_phandle_args *args) > return iommu_fwspec_add_ids(dev, args->args, 1); > } > > +static bool viommu_capable(enum iommu_cap cap) > +{ > + if (cap == IOMMU_CAP_VIOMMU) > + return true; > + > + return false; > +} > + > static struct iommu_ops viommu_ops = { > + .capable = viommu_capable, > .domain_alloc = viommu_domain_alloc, > .domain_free = viommu_domain_free, > .attach_dev = viommu_attach_dev, > diff --git a/include/linux/iommu.h b/include/linux/iommu.h > index b95a6f8db6ff..1d24be667a03 100644 > --- a/include/linux/iommu.h > +++ b/include/linux/iommu.h > @@ -94,6 +94,7 @@ enum iommu_cap { > transactions */ > IOMMU_CAP_INTR_REMAP, /* IOMMU supports interrupt isolation */ > IOMMU_CAP_NOEXEC, /* IOMMU_NOEXEC flag */ > + IOMMU_CAP_VIOMMU, /* IOMMU can declar running in a VM */ > }; > > /*
On Fri, Jan 15, 2021 at 07:49:47AM +0800, Lu Baolu wrote: > Hi Leon, > > On 1/14/21 9:26 PM, Leon Romanovsky wrote: > > On Thu, Jan 14, 2021 at 09:30:02AM +0800, Lu Baolu wrote: > > > Some vendor IOMMU drivers are able to declare that it is running in a VM > > > context. This is very valuable for the features that only want to be > > > supported on bare metal. Add a capability bit so that it could be used. > > > > And how is it used? Who and how will set it? > > Use the existing iommu_capable(). I should add more descriptions about > who and how to use it. I want to see the code that sets this capability. Thanks
Hi, On 2021/1/15 14:31, Leon Romanovsky wrote: > On Fri, Jan 15, 2021 at 07:49:47AM +0800, Lu Baolu wrote: >> Hi Leon, >> >> On 1/14/21 9:26 PM, Leon Romanovsky wrote: >>> On Thu, Jan 14, 2021 at 09:30:02AM +0800, Lu Baolu wrote: >>>> Some vendor IOMMU drivers are able to declare that it is running in a VM >>>> context. This is very valuable for the features that only want to be >>>> supported on bare metal. Add a capability bit so that it could be used. >>> >>> And how is it used? Who and how will set it? >> >> Use the existing iommu_capable(). I should add more descriptions about >> who and how to use it. > > I want to see the code that sets this capability. Currently we have Intel VT-d and the virt-iommu setting this capability. static bool intel_iommu_capable(enum iommu_cap cap) { if (cap == IOMMU_CAP_CACHE_COHERENCY) return domain_update_iommu_snooping(NULL) == 1; if (cap == IOMMU_CAP_INTR_REMAP) return irq_remapping_enabled == 1; + if (cap == IOMMU_CAP_VIOMMU) + return caching_mode_enabled(); return false; } And, +static bool viommu_capable(enum iommu_cap cap) +{ + if (cap == IOMMU_CAP_VIOMMU) + return true; + + return false; +} Best regards, baolu
On Sat, Jan 16, 2021 at 09:20:16AM +0800, Lu Baolu wrote: > Hi, > > On 2021/1/15 14:31, Leon Romanovsky wrote: > > On Fri, Jan 15, 2021 at 07:49:47AM +0800, Lu Baolu wrote: > > > Hi Leon, > > > > > > On 1/14/21 9:26 PM, Leon Romanovsky wrote: > > > > On Thu, Jan 14, 2021 at 09:30:02AM +0800, Lu Baolu wrote: > > > > > Some vendor IOMMU drivers are able to declare that it is running in a VM > > > > > context. This is very valuable for the features that only want to be > > > > > supported on bare metal. Add a capability bit so that it could be used. > > > > > > > > And how is it used? Who and how will set it? > > > > > > Use the existing iommu_capable(). I should add more descriptions about > > > who and how to use it. > > > > I want to see the code that sets this capability. > > Currently we have Intel VT-d and the virt-iommu setting this capability. > > static bool intel_iommu_capable(enum iommu_cap cap) > { > if (cap == IOMMU_CAP_CACHE_COHERENCY) > return domain_update_iommu_snooping(NULL) == 1; > if (cap == IOMMU_CAP_INTR_REMAP) > return irq_remapping_enabled == 1; > + if (cap == IOMMU_CAP_VIOMMU) > + return caching_mode_enabled(); > > return false; > } > > And, > > +static bool viommu_capable(enum iommu_cap cap) > +{ > + if (cap == IOMMU_CAP_VIOMMU) > + return true; > + > + return false; > +} These two functions are reading this cap and not setting. Where can I see code that does "cap = IOMMU_CAP_VIOMMU" and not "=="? > > Best regards, > baolu
Hi Leon, On 2021/1/16 16:39, Leon Romanovsky wrote: > On Sat, Jan 16, 2021 at 09:20:16AM +0800, Lu Baolu wrote: >> Hi, >> >> On 2021/1/15 14:31, Leon Romanovsky wrote: >>> On Fri, Jan 15, 2021 at 07:49:47AM +0800, Lu Baolu wrote: >>>> Hi Leon, >>>> >>>> On 1/14/21 9:26 PM, Leon Romanovsky wrote: >>>>> On Thu, Jan 14, 2021 at 09:30:02AM +0800, Lu Baolu wrote: >>>>>> Some vendor IOMMU drivers are able to declare that it is running in a VM >>>>>> context. This is very valuable for the features that only want to be >>>>>> supported on bare metal. Add a capability bit so that it could be used. >>>>> >>>>> And how is it used? Who and how will set it? >>>> >>>> Use the existing iommu_capable(). I should add more descriptions about >>>> who and how to use it. >>> >>> I want to see the code that sets this capability. >> >> Currently we have Intel VT-d and the virt-iommu setting this capability. >> >> static bool intel_iommu_capable(enum iommu_cap cap) >> { >> if (cap == IOMMU_CAP_CACHE_COHERENCY) >> return domain_update_iommu_snooping(NULL) == 1; >> if (cap == IOMMU_CAP_INTR_REMAP) >> return irq_remapping_enabled == 1; >> + if (cap == IOMMU_CAP_VIOMMU) >> + return caching_mode_enabled(); >> >> return false; >> } >> >> And, >> >> +static bool viommu_capable(enum iommu_cap cap) >> +{ >> + if (cap == IOMMU_CAP_VIOMMU) >> + return true; >> + >> + return false; >> +} > > These two functions are reading this cap and not setting. > Where can I see code that does "cap = IOMMU_CAP_VIOMMU" and not "=="? The iommu_capable() is a generic IOMMU interface to query IOMMU capabilities. It takes @bus and @cap as input, and calls the callback of vendor iommu. If the vendor iommu driver supports the specific capability, it returns true. Otherwise, it returns false. bool iommu_capable(struct bus_type *bus, enum iommu_cap cap) { if (!bus->iommu_ops || !bus->iommu_ops->capable) return false; return bus->iommu_ops->capable(cap); } EXPORT_SYMBOL_GPL(iommu_capable); In the vendor iommu's callback, it checks the capability and returns a value according to its capability, just as showed above. Best regards, baolu
On Sat, Jan 16, 2021 at 04:47:40PM +0800, Lu Baolu wrote: > Hi Leon, > > On 2021/1/16 16:39, Leon Romanovsky wrote: > > On Sat, Jan 16, 2021 at 09:20:16AM +0800, Lu Baolu wrote: > > > Hi, > > > > > > On 2021/1/15 14:31, Leon Romanovsky wrote: > > > > On Fri, Jan 15, 2021 at 07:49:47AM +0800, Lu Baolu wrote: > > > > > Hi Leon, > > > > > > > > > > On 1/14/21 9:26 PM, Leon Romanovsky wrote: > > > > > > On Thu, Jan 14, 2021 at 09:30:02AM +0800, Lu Baolu wrote: > > > > > > > Some vendor IOMMU drivers are able to declare that it is running in a VM > > > > > > > context. This is very valuable for the features that only want to be > > > > > > > supported on bare metal. Add a capability bit so that it could be used. > > > > > > > > > > > > And how is it used? Who and how will set it? > > > > > > > > > > Use the existing iommu_capable(). I should add more descriptions about > > > > > who and how to use it. > > > > > > > > I want to see the code that sets this capability. > > > > > > Currently we have Intel VT-d and the virt-iommu setting this capability. > > > > > > static bool intel_iommu_capable(enum iommu_cap cap) > > > { > > > if (cap == IOMMU_CAP_CACHE_COHERENCY) > > > return domain_update_iommu_snooping(NULL) == 1; > > > if (cap == IOMMU_CAP_INTR_REMAP) > > > return irq_remapping_enabled == 1; > > > + if (cap == IOMMU_CAP_VIOMMU) > > > + return caching_mode_enabled(); > > > > > > return false; > > > } > > > > > > And, > > > > > > +static bool viommu_capable(enum iommu_cap cap) > > > +{ > > > + if (cap == IOMMU_CAP_VIOMMU) > > > + return true; > > > + > > > + return false; > > > +} > > > > These two functions are reading this cap and not setting. > > Where can I see code that does "cap = IOMMU_CAP_VIOMMU" and not "=="? > > The iommu_capable() is a generic IOMMU interface to query IOMMU > capabilities. It takes @bus and @cap as input, and calls the callback > of vendor iommu. If the vendor iommu driver supports the specific > capability, it returns true. Otherwise, it returns false. > > bool iommu_capable(struct bus_type *bus, enum iommu_cap cap) > { > if (!bus->iommu_ops || !bus->iommu_ops->capable) > return false; > > return bus->iommu_ops->capable(cap); > } > EXPORT_SYMBOL_GPL(iommu_capable); > > In the vendor iommu's callback, it checks the capability and returns a > value according to its capability, just as showed above. Ohh, sorry. I missed "iommu_capable(dev->bus, IOMMU_CAP_VIOMMU)" from second patch. Thanks > > Best regards, > baolu
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index cb205a04fe4c..8eb022d0e8aa 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -5738,12 +5738,32 @@ static inline bool nested_mode_support(void) return ret; } +static inline bool caching_mode_enabled(void) +{ + struct dmar_drhd_unit *drhd; + struct intel_iommu *iommu; + bool ret = false; + + rcu_read_lock(); + for_each_active_iommu(iommu, drhd) { + if (cap_caching_mode(iommu->cap)) { + ret = true; + break; + } + } + rcu_read_unlock(); + + return ret; +} + static bool intel_iommu_capable(enum iommu_cap cap) { if (cap == IOMMU_CAP_CACHE_COHERENCY) return domain_update_iommu_snooping(NULL) == 1; if (cap == IOMMU_CAP_INTR_REMAP) return irq_remapping_enabled == 1; + if (cap == IOMMU_CAP_VIOMMU) + return caching_mode_enabled(); return false; } diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c index 2bfdd5734844..719793e103db 100644 --- a/drivers/iommu/virtio-iommu.c +++ b/drivers/iommu/virtio-iommu.c @@ -931,7 +931,16 @@ static int viommu_of_xlate(struct device *dev, struct of_phandle_args *args) return iommu_fwspec_add_ids(dev, args->args, 1); } +static bool viommu_capable(enum iommu_cap cap) +{ + if (cap == IOMMU_CAP_VIOMMU) + return true; + + return false; +} + static struct iommu_ops viommu_ops = { + .capable = viommu_capable, .domain_alloc = viommu_domain_alloc, .domain_free = viommu_domain_free, .attach_dev = viommu_attach_dev, diff --git a/include/linux/iommu.h b/include/linux/iommu.h index b95a6f8db6ff..1d24be667a03 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -94,6 +94,7 @@ enum iommu_cap { transactions */ IOMMU_CAP_INTR_REMAP, /* IOMMU supports interrupt isolation */ IOMMU_CAP_NOEXEC, /* IOMMU_NOEXEC flag */ + IOMMU_CAP_VIOMMU, /* IOMMU can declar running in a VM */ }; /*
Some vendor IOMMU drivers are able to declare that it is running in a VM context. This is very valuable for the features that only want to be supported on bare metal. Add a capability bit so that it could be used. Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> --- drivers/iommu/intel/iommu.c | 20 ++++++++++++++++++++ drivers/iommu/virtio-iommu.c | 9 +++++++++ include/linux/iommu.h | 1 + 3 files changed, 30 insertions(+)