| Message ID | 20210910153627.1060858-17-daniele.ceraolospurio@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/i915: Introduce Intel PXP | expand |
On Fri, Sep 10, 2021 at 08:36:26AM -0700, Daniele Ceraolo Spurio wrote: > Now that all the pieces are in place we can add a description of how the > feature works. Also modify the comments in struct intel_pxp into > kerneldoc. > > v2: improve doc (Rodrigo) > > Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com> > Cc: Daniel Vetter <daniel.vetter@intel.com> > Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com> > --- > Documentation/gpu/i915.rst | 8 ++++ > drivers/gpu/drm/i915/pxp/intel_pxp.c | 28 +++++++++++++ > drivers/gpu/drm/i915/pxp/intel_pxp_types.h | 47 ++++++++++++++++------ > 3 files changed, 71 insertions(+), 12 deletions(-) > > diff --git a/Documentation/gpu/i915.rst b/Documentation/gpu/i915.rst > index 101dde3eb1ea..78ecb9d5ec20 100644 > --- a/Documentation/gpu/i915.rst > +++ b/Documentation/gpu/i915.rst > @@ -471,6 +471,14 @@ Object Tiling IOCTLs > .. kernel-doc:: drivers/gpu/drm/i915/gem/i915_gem_tiling.c > :doc: buffer object tiling > > +Protected Objects > +----------------- > + > +.. kernel-doc:: drivers/gpu/drm/i915/pxp/intel_pxp.c > + :doc: PXP > + > +.. kernel-doc:: drivers/gpu/drm/i915/pxp/intel_pxp_types.h > + > Microcontrollers > ================ > > diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp.c b/drivers/gpu/drm/i915/pxp/intel_pxp.c > index 97c6368fddc3..5610634f8929 100644 > --- a/drivers/gpu/drm/i915/pxp/intel_pxp.c > +++ b/drivers/gpu/drm/i915/pxp/intel_pxp.c > @@ -11,6 +11,34 @@ > #include "gt/intel_context.h" > #include "i915_drv.h" > > +/** > + * DOC: PXP > + * > + * PXP (Protected Xe Path) is a feature available in Gen12 and newer platforms. > + * It allows execution and flip to display of protected (i.e. encrypted) > + * objects. The SW support is enabled via the CONFIG_DRM_I915_PXP kconfig. > + * > + * Objects can opt-in to PXP encryption at creation time via the > + * I915_GEM_CREATE_EXT_PROTECTED_CONTENT create_ext flag. For objects to be > + * correctly protected they must be used in conjunction with a context created > + * with the I915_CONTEXT_PARAM_PROTECTED_CONTENT flag. See the documentation > + * of those two uapi flags for details and restrictions. > + * > + * Protected objects are tied to a pxp session; currently we only support one > + * session, which i915 manages and whose index is available in the uapi > + * (I915_PROTECTED_CONTENT_DEFAULT_SESSION) for use in instructions targeting > + * protected objects. > + * The session is invalidated by the HW when certain events occur (e.g. > + * suspend/resume). When this happens, all the objects that were used with the > + * session are marked as invalid and all contexts marked as using protected > + * content are banned. Any further attempt at using them in an execbuf call is > + * rejected, while flips are converted to black frames. > + * > + * Some of the PXP setup operations are performed by the Management Engine, > + * which is handled by the mei driver; communication between i915 and mei is > + * performed via the mei_pxp component module. > + */ > + > /* KCR register definitions */ > #define KCR_INIT _MMIO(0x320f0) > > diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_types.h b/drivers/gpu/drm/i915/pxp/intel_pxp_types.h > index ae24064bb57e..73ef7d1754e1 100644 > --- a/drivers/gpu/drm/i915/pxp/intel_pxp_types.h > +++ b/drivers/gpu/drm/i915/pxp/intel_pxp_types.h > @@ -16,42 +16,65 @@ > struct intel_context; > struct i915_pxp_component; > > +/** > + * struct intel_pxp - pxp state > + */ > struct intel_pxp { > + /** > + * @pxp_component: i915_pxp_component struct of the bound mei_pxp > + * module. Only set and cleared inside component bind/unbind functions, > + * which are protected by &tee_mutex. > + */ > struct i915_pxp_component *pxp_component; > + /** > + * @pxp_component_added: track if the pxp component has been added. > + * Set and cleared in tee init and fini functions respectively. > + */ > bool pxp_component_added; > > + /** @ce: kernel-owned context used for PXP operations */ > struct intel_context *ce; > > - /* > + /** @arb_mutex: protects arb session start */ > + struct mutex arb_mutex; > + /** > + * @arb_is_valid: tracks arb session status. > * After a teardown, the arb session can still be in play on the HW > * even if the keys are gone, so we can't rely on the HW state of the > * session to know if it's valid and need to track the status in SW. > */ > - struct mutex arb_mutex; /* protects arb session start */ > bool arb_is_valid; > > - /* > - * Keep track of which key instance we're on, so we can use it to > - * determine if an object was created using the current key or a > + /** > + * @key_instance: tracks which key instance we're on, so we can use it > + * to determine if an object was created using the current key or a > * previous one. > */ > u32 key_instance; > > - struct mutex tee_mutex; /* protects the tee channel binding */ > + /** @tee_mutex: protects the tee channel binding and messaging. */ > + struct mutex tee_mutex; > > - /* > - * If the HW perceives an attack on the integrity of the encryption it > - * will invalidate the keys and expect SW to re-initialize the session. > - * We keep track of this state to make sure we only re-start the arb > - * session when required. > + /** > + * @hw_state_invalidated: if the HW perceives an attack on the integrity > + * of the encryption it will invalidate the keys and expect SW to > + * re-initialize the session. We keep track of this state to make sure > + * we only re-start the arb session when required. > */ > bool hw_state_invalidated; > > + /** @irq_enabled: tracks the status of the kcr irqs */ > bool irq_enabled; > + /** > + * @termination: tracks the status of a pending termination. Only > + * re-initialized under gt->irq_lock and completed in &session_work. > + */ > struct completion termination; > > + /** @session_work: worker that manages session events. */ > struct work_struct session_work; > - u32 session_events; /* protected with gt->irq_lock */ > + /** @session_events: pending session events, protected with gt->irq_lock. */ > + u32 session_events; > #define PXP_TERMINATION_REQUEST BIT(0) > #define PXP_TERMINATION_COMPLETE BIT(1) > #define PXP_INVAL_REQUIRED BIT(2) > -- > 2.25.1 >
diff --git a/Documentation/gpu/i915.rst b/Documentation/gpu/i915.rst index 101dde3eb1ea..78ecb9d5ec20 100644 --- a/Documentation/gpu/i915.rst +++ b/Documentation/gpu/i915.rst @@ -471,6 +471,14 @@ Object Tiling IOCTLs .. kernel-doc:: drivers/gpu/drm/i915/gem/i915_gem_tiling.c :doc: buffer object tiling +Protected Objects +----------------- + +.. kernel-doc:: drivers/gpu/drm/i915/pxp/intel_pxp.c + :doc: PXP + +.. kernel-doc:: drivers/gpu/drm/i915/pxp/intel_pxp_types.h + Microcontrollers ================ diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp.c b/drivers/gpu/drm/i915/pxp/intel_pxp.c index 97c6368fddc3..5610634f8929 100644 --- a/drivers/gpu/drm/i915/pxp/intel_pxp.c +++ b/drivers/gpu/drm/i915/pxp/intel_pxp.c @@ -11,6 +11,34 @@ #include "gt/intel_context.h" #include "i915_drv.h" +/** + * DOC: PXP + * + * PXP (Protected Xe Path) is a feature available in Gen12 and newer platforms. + * It allows execution and flip to display of protected (i.e. encrypted) + * objects. The SW support is enabled via the CONFIG_DRM_I915_PXP kconfig. + * + * Objects can opt-in to PXP encryption at creation time via the + * I915_GEM_CREATE_EXT_PROTECTED_CONTENT create_ext flag. For objects to be + * correctly protected they must be used in conjunction with a context created + * with the I915_CONTEXT_PARAM_PROTECTED_CONTENT flag. See the documentation + * of those two uapi flags for details and restrictions. + * + * Protected objects are tied to a pxp session; currently we only support one + * session, which i915 manages and whose index is available in the uapi + * (I915_PROTECTED_CONTENT_DEFAULT_SESSION) for use in instructions targeting + * protected objects. + * The session is invalidated by the HW when certain events occur (e.g. + * suspend/resume). When this happens, all the objects that were used with the + * session are marked as invalid and all contexts marked as using protected + * content are banned. Any further attempt at using them in an execbuf call is + * rejected, while flips are converted to black frames. + * + * Some of the PXP setup operations are performed by the Management Engine, + * which is handled by the mei driver; communication between i915 and mei is + * performed via the mei_pxp component module. + */ + /* KCR register definitions */ #define KCR_INIT _MMIO(0x320f0) diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_types.h b/drivers/gpu/drm/i915/pxp/intel_pxp_types.h index ae24064bb57e..73ef7d1754e1 100644 --- a/drivers/gpu/drm/i915/pxp/intel_pxp_types.h +++ b/drivers/gpu/drm/i915/pxp/intel_pxp_types.h @@ -16,42 +16,65 @@ struct intel_context; struct i915_pxp_component; +/** + * struct intel_pxp - pxp state + */ struct intel_pxp { + /** + * @pxp_component: i915_pxp_component struct of the bound mei_pxp + * module. Only set and cleared inside component bind/unbind functions, + * which are protected by &tee_mutex. + */ struct i915_pxp_component *pxp_component; + /** + * @pxp_component_added: track if the pxp component has been added. + * Set and cleared in tee init and fini functions respectively. + */ bool pxp_component_added; + /** @ce: kernel-owned context used for PXP operations */ struct intel_context *ce; - /* + /** @arb_mutex: protects arb session start */ + struct mutex arb_mutex; + /** + * @arb_is_valid: tracks arb session status. * After a teardown, the arb session can still be in play on the HW * even if the keys are gone, so we can't rely on the HW state of the * session to know if it's valid and need to track the status in SW. */ - struct mutex arb_mutex; /* protects arb session start */ bool arb_is_valid; - /* - * Keep track of which key instance we're on, so we can use it to - * determine if an object was created using the current key or a + /** + * @key_instance: tracks which key instance we're on, so we can use it + * to determine if an object was created using the current key or a * previous one. */ u32 key_instance; - struct mutex tee_mutex; /* protects the tee channel binding */ + /** @tee_mutex: protects the tee channel binding and messaging. */ + struct mutex tee_mutex; - /* - * If the HW perceives an attack on the integrity of the encryption it - * will invalidate the keys and expect SW to re-initialize the session. - * We keep track of this state to make sure we only re-start the arb - * session when required. + /** + * @hw_state_invalidated: if the HW perceives an attack on the integrity + * of the encryption it will invalidate the keys and expect SW to + * re-initialize the session. We keep track of this state to make sure + * we only re-start the arb session when required. */ bool hw_state_invalidated; + /** @irq_enabled: tracks the status of the kcr irqs */ bool irq_enabled; + /** + * @termination: tracks the status of a pending termination. Only + * re-initialized under gt->irq_lock and completed in &session_work. + */ struct completion termination; + /** @session_work: worker that manages session events. */ struct work_struct session_work; - u32 session_events; /* protected with gt->irq_lock */ + /** @session_events: pending session events, protected with gt->irq_lock. */ + u32 session_events; #define PXP_TERMINATION_REQUEST BIT(0) #define PXP_TERMINATION_COMPLETE BIT(1) #define PXP_INVAL_REQUIRED BIT(2)
Now that all the pieces are in place we can add a description of how the feature works. Also modify the comments in struct intel_pxp into kerneldoc. v2: improve doc (Rodrigo) Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com> Cc: Daniel Vetter <daniel.vetter@intel.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> --- Documentation/gpu/i915.rst | 8 ++++ drivers/gpu/drm/i915/pxp/intel_pxp.c | 28 +++++++++++++ drivers/gpu/drm/i915/pxp/intel_pxp_types.h | 47 ++++++++++++++++------ 3 files changed, 71 insertions(+), 12 deletions(-)