On Thu, Jul 15, 2021 at 09:10:26PM -0700, Daniele Ceraolo Spurio wrote:
> From: "Huang, Sean Z" <sean.z.huang@xxxxxxxxx>
>
> Create the arbitrary session, with the fixed session id 0xf, after
> system boot, for the case that application allocates the protected
> buffer without establishing any protection session. Because the
> hardware requires at least one alive session for protected buffer
> creation. This arbitrary session will need to be re-created after
> teardown or power event because hardware encryption key won't be
> valid after such cases.
>
> The session ID is exposed as part of the uapi so it can be used as part
> of userspace commands.
>
> v2: use gt->uncore->rpm (Chris)
> v3: s/arb_is_in_play/arb_is_valid (Chris), move set-up to the new
> init_hw function
> v4: move interface defs to separate header, set arb_is valid to false
> on fini (Rodrigo)
> v5: handle async component binding
>
> Signed-off-by: Huang, Sean Z <sean.z.huang@xxxxxxxxx>
> Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@xxxxxxxxx>
> Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
> Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
> Reviewed-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> #v4
> ---
> drivers/gpu/drm/i915/Makefile | 1 +
> drivers/gpu/drm/i915/pxp/intel_pxp.c | 7 ++
> drivers/gpu/drm/i915/pxp/intel_pxp.h | 5 ++
> drivers/gpu/drm/i915/pxp/intel_pxp_session.c | 74 ++++++++++++++++
> drivers/gpu/drm/i915/pxp/intel_pxp_session.h | 15 ++++
> drivers/gpu/drm/i915/pxp/intel_pxp_tee.c | 87 +++++++++++++++++++
> drivers/gpu/drm/i915/pxp/intel_pxp_tee.h | 3 +
> .../drm/i915/pxp/intel_pxp_tee_interface.h | 37 ++++++++
> drivers/gpu/drm/i915/pxp/intel_pxp_types.h | 12 +++
> include/uapi/drm/i915_drm.h | 3 +
> 10 files changed, 244 insertions(+)
> create mode 100644 drivers/gpu/drm/i915/pxp/intel_pxp_session.c
> create mode 100644 drivers/gpu/drm/i915/pxp/intel_pxp_session.h
> create mode 100644 drivers/gpu/drm/i915/pxp/intel_pxp_tee_interface.h
>
> diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
> index 05eb6b7753cc..946b56cff9cf 100644
> --- a/drivers/gpu/drm/i915/Makefile
> +++ b/drivers/gpu/drm/i915/Makefile
> @@ -278,6 +278,7 @@ i915-y += i915_perf.o
> # Protected execution platform (PXP) support
> i915-$(CONFIG_DRM_I915_PXP) += \
> pxp/intel_pxp.o \
> + pxp/intel_pxp_session.o \
> pxp/intel_pxp_tee.o
>
> # Post-mortem debug and GPU hang state capture
> diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp.c b/drivers/gpu/drm/i915/pxp/intel_pxp.c
> index 66a98feb33ab..e1370f323126 100644
> --- a/drivers/gpu/drm/i915/pxp/intel_pxp.c
> +++ b/drivers/gpu/drm/i915/pxp/intel_pxp.c
> @@ -3,6 +3,7 @@
> * Copyright(c) 2020 Intel Corporation.
> */
> #include "intel_pxp.h"
> +#include "intel_pxp_session.h"
> #include "intel_pxp_tee.h"
> #include "gt/intel_context.h"
> #include "i915_drv.h"
> @@ -65,6 +66,8 @@ void intel_pxp_init(struct intel_pxp *pxp)
> if (!HAS_PXP(gt->i915))
> return;
>
> + mutex_init(&pxp->tee_mutex);
> +
> ret = create_vcs_context(pxp);
> if (ret)
> return;
> @@ -86,6 +89,8 @@ void intel_pxp_fini(struct intel_pxp *pxp)
> if (!intel_pxp_is_enabled(pxp))
> return;
>
> + pxp->arb_is_valid = false;
> +
> intel_pxp_tee_component_fini(pxp);
>
> destroy_vcs_context(pxp);
> @@ -94,6 +99,8 @@ void intel_pxp_fini(struct intel_pxp *pxp)
> void intel_pxp_init_hw(struct intel_pxp *pxp)
> {
> kcr_pxp_enable(pxp_to_gt(pxp));
> +
> + intel_pxp_create_arb_session(pxp);
> }
>
> void intel_pxp_fini_hw(struct intel_pxp *pxp)
> diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp.h b/drivers/gpu/drm/i915/pxp/intel_pxp.h
> index 5427c3b28aa9..8eeb65af78b1 100644
> --- a/drivers/gpu/drm/i915/pxp/intel_pxp.h
> +++ b/drivers/gpu/drm/i915/pxp/intel_pxp.h
> @@ -19,6 +19,11 @@ static inline bool intel_pxp_is_enabled(const struct intel_pxp *pxp)
> return pxp->ce;
> }
>
> +static inline bool intel_pxp_is_active(const struct intel_pxp *pxp)
> +{
> + return pxp->arb_is_valid;
> +}
> +
> #ifdef CONFIG_DRM_I915_PXP
> void intel_pxp_init(struct intel_pxp *pxp);
> void intel_pxp_fini(struct intel_pxp *pxp);
> diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_session.c b/drivers/gpu/drm/i915/pxp/intel_pxp_session.c
> new file mode 100644
> index 000000000000..3331868f354c
> --- /dev/null
> +++ b/drivers/gpu/drm/i915/pxp/intel_pxp_session.c
> @@ -0,0 +1,74 @@
> +// SPDX-License-Identifier: MIT
> +/*
> + * Copyright(c) 2020, Intel Corporation. All rights reserved.
> + */
> +
> +#include "drm/i915_drm.h"
> +#include "i915_drv.h"
> +
> +#include "intel_pxp.h"
> +#include "intel_pxp_session.h"
> +#include "intel_pxp_tee.h"
> +#include "intel_pxp_types.h"
> +
> +#define ARB_SESSION I915_PROTECTED_CONTENT_DEFAULT_SESSION /* shorter define */
> +
> +#define GEN12_KCR_SIP _MMIO(0x32260) /* KCR hwdrm session in play 0-31 */
> +
> +static bool intel_pxp_session_is_in_play(struct intel_pxp *pxp, u32 id)
> +{
> + struct intel_gt *gt = pxp_to_gt(pxp);
> + intel_wakeref_t wakeref;
> + u32 sip = 0;
> +
> + with_intel_runtime_pm(gt->uncore->rpm, wakeref)
> + sip = intel_uncore_read(gt->uncore, GEN12_KCR_SIP);
> +
> + return sip & BIT(id);
> +}
> +
> +static int pxp_wait_for_session_state(struct intel_pxp *pxp, u32 id, bool in_play)
> +{
> + struct intel_gt *gt = pxp_to_gt(pxp);
> + intel_wakeref_t wakeref;
> + u32 mask = BIT(id);
> + int ret;
> +
> + with_intel_runtime_pm(gt->uncore->rpm, wakeref)
> + ret = intel_wait_for_register(gt->uncore,
> + GEN12_KCR_SIP,
> + mask,
> + in_play ? mask : 0,
> + 100);
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
> +
> + return ret;
> +}
> +
> +int intel_pxp_create_arb_session(struct intel_pxp *pxp)
> +{
> + struct intel_gt *gt = pxp_to_gt(pxp);
> + int ret;
> +
> + pxp->arb_is_valid = false;
> +
> + if (intel_pxp_session_is_in_play(pxp, ARB_SESSION)) {
> + drm_err(>->i915->drm, "arb session already in play at creation time\n");
> + return -EEXIST;
> + }
> +
> + ret = intel_pxp_tee_cmd_create_arb_session(pxp, ARB_SESSION);
> + if (ret) {
> + drm_err(>->i915->drm, "tee cmd for arb session creation failed\n");
> + return ret;
> + }
> +
> + ret = pxp_wait_for_session_state(pxp, ARB_SESSION, true);
> + if (ret) {
> + drm_err(>->i915->drm, "arb session failed to go in play\n");
> + return ret;
> + }
> +
> + pxp->arb_is_valid = true;
> +
> + return 0;
> +}
> diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_session.h b/drivers/gpu/drm/i915/pxp/intel_pxp_session.h
> new file mode 100644
> index 000000000000..316c3bebed9c
> --- /dev/null
> +++ b/drivers/gpu/drm/i915/pxp/intel_pxp_session.h
> @@ -0,0 +1,15 @@
> +/* SPDX-License-Identifier: MIT */
> +/*
> + * Copyright(c) 2020, Intel Corporation. All rights reserved.
> + */
> +
> +#ifndef __INTEL_PXP_SESSION_H__
> +#define __INTEL_PXP_SESSION_H__
> +
> +#include <linux/types.h>
> +
> +struct intel_pxp;
> +
> +int intel_pxp_create_arb_session(struct intel_pxp *pxp);
> +
> +#endif /* __INTEL_PXP_SESSION_H__ */
> diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_tee.c b/drivers/gpu/drm/i915/pxp/intel_pxp_tee.c
> index 33130fb7113b..3662bf67407a 100644
> --- a/drivers/gpu/drm/i915/pxp/intel_pxp_tee.c
> +++ b/drivers/gpu/drm/i915/pxp/intel_pxp_tee.c
> @@ -8,13 +8,63 @@
> #include "drm/i915_component.h"
> #include "i915_drv.h"
> #include "intel_pxp.h"
> +#include "intel_pxp_session.h"
> #include "intel_pxp_tee.h"
> +#include "intel_pxp_tee_interface.h"
>
> static inline struct intel_pxp *i915_dev_to_pxp(struct device *i915_kdev)
> {
> return &kdev_to_i915(i915_kdev)->gt.pxp;
> }
>
> +static int intel_pxp_tee_io_message(struct intel_pxp *pxp,
> + void *msg_in, u32 msg_in_size,
> + void *msg_out, u32 msg_out_max_size,
> + u32 *msg_out_rcv_size)
> +{
> + struct drm_i915_private *i915 = pxp_to_gt(pxp)->i915;
> + struct i915_pxp_component *pxp_component = pxp->pxp_component;
> + int ret = 0;
> +
> + mutex_lock(&pxp->tee_mutex);
> +
> + /*
> + * The binding of the component is asynchronous from i915 probe, so we
> + * can't be sure it has happened.
> + */
> + if (!pxp_component) {
> + ret = -ENODEV;
> + goto unlock;
> + }
> +
> + ret = pxp_component->ops->send(pxp_component->tee_dev, msg_in, msg_in_size);
> + if (ret) {
> + drm_err(&i915->drm, "Failed to send PXP TEE message\n");
> + goto unlock;
> + }
> +
> + ret = pxp_component->ops->recv(pxp_component->tee_dev, msg_out, msg_out_max_size);
> + if (ret < 0) {
> + drm_err(&i915->drm, "Failed to receive PXP TEE message\n");
> + goto unlock;
> + }
> +
> + if (ret > msg_out_max_size) {
> + drm_err(&i915->drm,
> + "Failed to receive PXP TEE message due to unexpected output size\n");
> + ret = -ENOSPC;
> + goto unlock;
> + }
> +
> + if (msg_out_rcv_size)
> + *msg_out_rcv_size = ret;
> +
> + ret = 0;
> +unlock:
> + mutex_unlock(&pxp->tee_mutex);
> + return ret;
> +}
> +
> /**
> * i915_pxp_tee_component_bind - bind function to pass the function pointers to pxp_tee
> * @i915_kdev: pointer to i915 kernel device
> @@ -28,14 +78,24 @@ static inline struct intel_pxp *i915_dev_to_pxp(struct device *i915_kdev)
> static int i915_pxp_tee_component_bind(struct device *i915_kdev,
> struct device *tee_kdev, void *data)
> {
> + struct drm_i915_private *i915 = kdev_to_i915(i915_kdev);
> struct intel_pxp *pxp = i915_dev_to_pxp(i915_kdev);
>
> + mutex_lock(&pxp->tee_mutex);
> pxp->pxp_component = data;
> pxp->pxp_component->tee_dev = tee_kdev;
> + mutex_unlock(&pxp->tee_mutex);
>
> /* the component is required to fully start the PXP HW */
> intel_pxp_init_hw(pxp);
>
> + if (!pxp->arb_is_valid) {
> + drm_err(&i915->drm, "Failed to create arb session during bind\n");
> + intel_pxp_fini_hw(pxp);
> + pxp->pxp_component = NULL;
> + return -EIO;
> + }
> +
> return 0;
> }
>
> @@ -46,7 +106,9 @@ static void i915_pxp_tee_component_unbind(struct device *i915_kdev,
>
> intel_pxp_fini_hw(pxp);
>
> + mutex_lock(&pxp->tee_mutex);
> pxp->pxp_component = NULL;
> + mutex_unlock(&pxp->tee_mutex);
> }
>
> static const struct component_ops i915_pxp_tee_component_ops = {
> @@ -80,3 +142,28 @@ void intel_pxp_tee_component_fini(struct intel_pxp *pxp)
>
> component_del(i915->drm.dev, &i915_pxp_tee_component_ops);
> }
> +
> +int intel_pxp_tee_cmd_create_arb_session(struct intel_pxp *pxp,
> + int arb_session_id)
> +{
> + struct drm_i915_private *i915 = pxp_to_gt(pxp)->i915;
> + struct pxp_tee_create_arb_in msg_in = {0};
> + struct pxp_tee_create_arb_out msg_out = {0};
> + int ret;
> +
> + msg_in.header.api_version = PXP_TEE_APIVER;
> + msg_in.header.command_id = PXP_TEE_ARB_CMDID;
> + msg_in.header.buffer_len = sizeof(msg_in) - sizeof(msg_in.header);
> + msg_in.protection_mode = PXP_TEE_ARB_PROTECTION_MODE;
> + msg_in.session_id = arb_session_id;
> +
> + ret = intel_pxp_tee_io_message(pxp,
> + &msg_in, sizeof(msg_in),
> + &msg_out, sizeof(msg_out),
> + NULL);
> +
> + if (ret)
> + drm_err(&i915->drm, "Failed to send tee msg ret=[%d]\n", ret);
> +
> + return ret;
> +}
> diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_tee.h b/drivers/gpu/drm/i915/pxp/intel_pxp_tee.h
> index 23d050a5d3e7..c136053ce340 100644
> --- a/drivers/gpu/drm/i915/pxp/intel_pxp_tee.h
> +++ b/drivers/gpu/drm/i915/pxp/intel_pxp_tee.h
> @@ -11,4 +11,7 @@
> int intel_pxp_tee_component_init(struct intel_pxp *pxp);
> void intel_pxp_tee_component_fini(struct intel_pxp *pxp);
>
> +int intel_pxp_tee_cmd_create_arb_session(struct intel_pxp *pxp,
> + int arb_session_id);
> +
> #endif /* __INTEL_PXP_TEE_H__ */
> diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_tee_interface.h b/drivers/gpu/drm/i915/pxp/intel_pxp_tee_interface.h
> new file mode 100644
> index 000000000000..1af6c0061e11
> --- /dev/null
> +++ b/drivers/gpu/drm/i915/pxp/intel_pxp_tee_interface.h
> @@ -0,0 +1,37 @@
> +/* SPDX-License-Identifier: MIT */
> +/*
> + * Copyright(c) 2020, Intel Corporation. All rights reserved.
> + */
> +
> +#ifndef __INTEL_PXP_TEE_INTERFACE_H__
> +#define __INTEL_PXP_TEE_INTERFACE_H__
> +
> +#include <linux/types.h>
> +
> +#define PXP_TEE_APIVER 0x40002
> +#define PXP_TEE_ARB_CMDID 0x1e
> +#define PXP_TEE_ARB_PROTECTION_MODE 0x2
> +
> +/* PXP TEE message header */
> +struct pxp_tee_cmd_header {
> + u32 api_version;
> + u32 command_id;
> + u32 status;
> + /* Length of the message (excluding the header) */
> + u32 buffer_len;
> +} __packed;
> +
> +/* PXP TEE message input to create a arbitrary session */
> +struct pxp_tee_create_arb_in {
> + struct pxp_tee_cmd_header header;
> + u32 protection_mode;
> + u32 session_id;
> +} __packed;
> +
> +/* PXP TEE message output to create a arbitrary session */
> +struct pxp_tee_create_arb_out {
> + struct pxp_tee_cmd_header header;
> +} __packed;
> +
> +
> +#endif /* __INTEL_PXP_TEE_INTERFACE_H__ */
> diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_types.h b/drivers/gpu/drm/i915/pxp/intel_pxp_types.h
> index 3e95d21513e8..a4797a98c1f9 100644
> --- a/drivers/gpu/drm/i915/pxp/intel_pxp_types.h
> +++ b/drivers/gpu/drm/i915/pxp/intel_pxp_types.h
> @@ -6,6 +6,9 @@
> #ifndef __INTEL_PXP_TYPES_H__
> #define __INTEL_PXP_TYPES_H__
>
> +#include <linux/mutex.h>
> +#include <linux/types.h>
> +
> struct intel_context;
> struct i915_pxp_component;
>
> @@ -13,6 +16,15 @@ struct intel_pxp {
> struct i915_pxp_component *pxp_component;
>
> struct intel_context *ce;
> +
> + /*
> + * 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.
> + */
> + bool arb_is_valid;
> +
> + struct mutex tee_mutex; /* protects the tee channel binding */
> };
>
> #endif /* __INTEL_PXP_TYPES_H__ */
> diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
> index e54f9efaead0..5296e4f77e0a 100644
> --- a/include/uapi/drm/i915_drm.h
> +++ b/include/uapi/drm/i915_drm.h
> @@ -2898,6 +2898,9 @@ struct drm_i915_gem_create_ext_memory_regions {
> __u64 regions;
> };
>
> +/* ID of the protected content session managed by i915 when PXP is active */
> +#define I915_PROTECTED_CONTENT_DEFAULT_SESSION 0xf
> +
> #if defined(__cplusplus)
> }
> #endif
> --
> 2.32.0
>
