Re: [PATCH 23/32] drm/amdkfd: add debug wave launch override operation

[Felix Kuehling <felix.kuehling@xxxxxxx>]

On 2023-01-25 14:53, Jonathan Kim wrote:
> This operation allows the debugger to override the enabled HW
> exceptions on the device.
>
> On debug devices that only support the debugging of a single process,
> the HW exceptions are global and set through the SPI_GDBG_TRAP_MASK
> register.
> Because they are global, only address watch exceptions are allowed to
> be enabled.  In other words, the debugger must preserve all non-address
> watch exception states in normal mode operation by barring a full
> replacement override or a non-address watch override request.
>
> For multi-process debugging, all HW exception overrides are per-VMID so
> all exceptions can be overridden or fully replaced.
>
> In order for the debugger to know what is permissible, returned the
> supported override mask back to the debugger along with the previously
> enable overrides.
>
> v3: v2 was reviewed but requesting re-review for GFX11 added supported.
>
> v2: switch unsupported override mode return from EPERM to EINVAL to
> support unique EPERM on PTRACE failure.
>
> Signed-off-by: Jonathan Kim <jonathan.kim@xxxxxxx>
> ---
>   .../drm/amd/amdgpu/amdgpu_amdkfd_aldebaran.c  | 47 ++++++++++
>   .../drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c   |  2 +
>   .../drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10.c    | 55 ++++++++++++
>   .../drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10.h    | 10 +++
>   .../drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10_3.c  |  5 +-
>   .../drm/amd/amdgpu/amdgpu_amdkfd_gfx_v11.c    | 86 ++++++++++++++++++-
>   .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.c | 55 ++++++++++++
>   .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.h | 10 +++
>   drivers/gpu/drm/amd/amdkfd/kfd_chardev.c      |  7 ++
>   drivers/gpu/drm/amd/amdkfd/kfd_debug.c        | 69 +++++++++++++++
>   drivers/gpu/drm/amd/amdkfd/kfd_debug.h        |  6 ++
>   11 files changed, 350 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_aldebaran.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_aldebaran.c
> index a64a53f9efe6..84a9d9391ea4 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_aldebaran.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_aldebaran.c
> @@ -25,6 +25,7 @@
>   #include "amdgpu_amdkfd_gfx_v9.h"
>   #include "gc/gc_9_4_2_offset.h"
>   #include "gc/gc_9_4_2_sh_mask.h"
> +#include <uapi/linux/kfd_ioctl.h>
>   
>   /**
>    * Returns TRAP_EN, EXCP_EN and EXCP_REPLACE.
> @@ -62,6 +63,50 @@ static uint32_t kgd_aldebaran_disable_debug_trap(struct amdgpu_device *adev,
>   	return data;
>   }
>   
> +static int kgd_aldebaran_validate_trap_override_request(struct amdgpu_device *adev,
> +							uint32_t trap_override,
> +							uint32_t *trap_mask_supported)
> +{
> +	*trap_mask_supported &= KFD_DBG_TRAP_MASK_FP_INVALID |
> +				KFD_DBG_TRAP_MASK_FP_INPUT_DENORMAL |
> +				KFD_DBG_TRAP_MASK_FP_DIVIDE_BY_ZERO |
> +				KFD_DBG_TRAP_MASK_FP_OVERFLOW |
> +				KFD_DBG_TRAP_MASK_FP_UNDERFLOW |
> +				KFD_DBG_TRAP_MASK_FP_INEXACT |
> +				KFD_DBG_TRAP_MASK_INT_DIVIDE_BY_ZERO |
> +				KFD_DBG_TRAP_MASK_DBG_ADDRESS_WATCH |
> +				KFD_DBG_TRAP_MASK_DBG_MEMORY_VIOLATION;
> +
> +	if (trap_override != KFD_DBG_TRAP_OVERRIDE_OR &&
> +			trap_override != KFD_DBG_TRAP_OVERRIDE_REPLACE)
> +		return -EPERM;
> +
> +	return 0;
> +}
> +
> +/* returns TRAP_EN, EXCP_EN and EXCP_RPLACE. */
> +static uint32_t kgd_aldebaran_set_wave_launch_trap_override(struct amdgpu_device *adev,
> +					uint32_t vmid,
> +					uint32_t trap_override,
> +					uint32_t trap_mask_bits,
> +					uint32_t trap_mask_request,
> +					uint32_t *trap_mask_prev,
> +					uint32_t kfd_dbg_trap_cntl_prev)
> +
> +{
> +	uint32_t data = 0;
> +
> +	*trap_mask_prev = REG_GET_FIELD(kfd_dbg_trap_cntl_prev, SPI_GDBG_PER_VMID_CNTL, EXCP_EN);
> +	trap_mask_bits = (trap_mask_bits & trap_mask_request) |
> +		(*trap_mask_prev & ~trap_mask_request);
> +
> +	data = REG_SET_FIELD(data, SPI_GDBG_PER_VMID_CNTL, TRAP_EN, 1);
> +	data = REG_SET_FIELD(data, SPI_GDBG_PER_VMID_CNTL, EXCP_EN, trap_mask_bits);
> +	data = REG_SET_FIELD(data, SPI_GDBG_PER_VMID_CNTL, EXCP_REPLACE, trap_override);
> +
> +	return data;
> +}
> +
>   const struct kfd2kgd_calls aldebaran_kfd2kgd = {
>   	.program_sh_mem_settings = kgd_gfx_v9_program_sh_mem_settings,
>   	.set_pasid_vmid_mapping = kgd_gfx_v9_set_pasid_vmid_mapping,
> @@ -81,6 +126,8 @@ const struct kfd2kgd_calls aldebaran_kfd2kgd = {
>   	.set_vm_context_page_table_base = kgd_gfx_v9_set_vm_context_page_table_base,
>   	.enable_debug_trap = kgd_aldebaran_enable_debug_trap,
>   	.disable_debug_trap = kgd_aldebaran_disable_debug_trap,
> +	.validate_trap_override_request = kgd_aldebaran_validate_trap_override_request,
> +	.set_wave_launch_trap_override = kgd_aldebaran_set_wave_launch_trap_override,
>   	.get_iq_wait_times = kgd_gfx_v9_get_iq_wait_times,
>   	.build_grace_period_packet_info = kgd_gfx_v9_build_grace_period_packet_info,
>   	.program_trap_handler_settings = kgd_gfx_v9_program_trap_handler_settings,
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c
> index ef8befc31fc6..0405725e95e3 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c
> @@ -410,6 +410,8 @@ const struct kfd2kgd_calls arcturus_kfd2kgd = {
>   				kgd_gfx_v9_set_vm_context_page_table_base,
>   	.enable_debug_trap = kgd_arcturus_enable_debug_trap,
>   	.disable_debug_trap = kgd_arcturus_disable_debug_trap,
> +	.validate_trap_override_request = kgd_gfx_v9_validate_trap_override_request,
> +	.set_wave_launch_trap_override = kgd_gfx_v9_set_wave_launch_trap_override,
>   	.get_iq_wait_times = kgd_gfx_v9_get_iq_wait_times,
>   	.build_grace_period_packet_info = kgd_gfx_v9_build_grace_period_packet_info,
>   	.get_cu_occupancy = kgd_gfx_v9_get_cu_occupancy,
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10.c
> index 2491402afd58..32a6e5fbeacd 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10.c
> @@ -31,6 +31,7 @@
>   #include "v10_structs.h"
>   #include "nv.h"
>   #include "nvd.h"
> +#include <uapi/linux/kfd_ioctl.h>
>   
>   enum hqd_dequeue_request_type {
>   	NO_ACTION = 0,
> @@ -801,6 +802,58 @@ uint32_t kgd_gfx_v10_disable_debug_trap(struct amdgpu_device *adev,
>   	return 0;
>   }
>   
> +int kgd_gfx_v10_validate_trap_override_request(struct amdgpu_device *adev,
> +					      uint32_t trap_override,
> +					      uint32_t *trap_mask_supported)
> +{
> +	*trap_mask_supported &= KFD_DBG_TRAP_MASK_DBG_ADDRESS_WATCH;
> +
> +	/* The SPI_GDBG_TRAP_MASK register is global and affects all
> +	 * processes. Only allow OR-ing the address-watch bit, since
> +	 * this only affects processes under the debugger. Other bits
> +	 * should stay 0 to avoid the debugger interfering with other
> +	 * processes.
> +	 */
> +	if (trap_override != KFD_DBG_TRAP_OVERRIDE_OR)
> +		return -EINVAL;
> +
> +	return 0;
> +}
> +
> +uint32_t kgd_gfx_v10_set_wave_launch_trap_override(struct amdgpu_device *adev,
> +					      uint32_t vmid,
> +					      uint32_t trap_override,
> +					      uint32_t trap_mask_bits,
> +					      uint32_t trap_mask_request,
> +					      uint32_t *trap_mask_prev,
> +					      uint32_t kfd_dbg_trap_cntl_prev)
> +{
> +	uint32_t data, wave_cntl_prev;
> +
> +	mutex_lock(&adev->grbm_idx_mutex);
> +
> +	wave_cntl_prev = RREG32(SOC15_REG_OFFSET(GC, 0, mmSPI_GDBG_WAVE_CNTL));
> +
> +	kgd_gfx_v10_set_wave_launch_stall(adev, vmid, true);
> +
> +	data = RREG32(SOC15_REG_OFFSET(GC, 0, mmSPI_GDBG_TRAP_MASK));
> +	*trap_mask_prev = REG_GET_FIELD(data, SPI_GDBG_TRAP_MASK, EXCP_EN);
> +
> +	trap_mask_bits = (trap_mask_bits & trap_mask_request) |
> +		(*trap_mask_prev & ~trap_mask_request);
> +
> +	data = REG_SET_FIELD(data, SPI_GDBG_TRAP_MASK, EXCP_EN, trap_mask_bits);
> +	data = REG_SET_FIELD(data, SPI_GDBG_TRAP_MASK, REPLACE, trap_override);
> +	WREG32(SOC15_REG_OFFSET(GC, 0, mmSPI_GDBG_TRAP_MASK), data);
> +
> +	/* We need to preserve wave launch mode stall settings. */
> +	WREG32(SOC15_REG_OFFSET(GC, 0, mmSPI_GDBG_WAVE_CNTL), wave_cntl_prev);
> +
> +	mutex_unlock(&adev->grbm_idx_mutex);
> +
> +	return 0;
> +}
> +
>   /* kgd_gfx_v10_get_iq_wait_times: Returns the mmCP_IQ_WAIT_TIME1/2 values
>    * The values read are:
>    *     ib_offload_wait_time     -- Wait Count for Indirect Buffer Offloads.
> @@ -886,6 +939,8 @@ const struct kfd2kgd_calls gfx_v10_kfd2kgd = {
>   	.set_vm_context_page_table_base = set_vm_context_page_table_base,
>   	.enable_debug_trap = kgd_gfx_v10_enable_debug_trap,
>   	.disable_debug_trap = kgd_gfx_v10_disable_debug_trap,
> +	.validate_trap_override_request = kgd_gfx_v10_validate_trap_override_request,
> +	.set_wave_launch_trap_override = kgd_gfx_v10_set_wave_launch_trap_override,
>   	.get_iq_wait_times = kgd_gfx_v10_get_iq_wait_times,
>   	.build_grace_period_packet_info = kgd_gfx_v10_build_grace_period_packet_info,
>   	.program_trap_handler_settings = program_trap_handler_settings,
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10.h
> index 0abc1e805180..85c929fc2926 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10.h
> @@ -26,6 +26,16 @@ uint32_t kgd_gfx_v10_enable_debug_trap(struct amdgpu_device *adev,
>   uint32_t kgd_gfx_v10_disable_debug_trap(struct amdgpu_device *adev,
>   					bool keep_trap_enabled,
>   					uint32_t vmid);
> +int kgd_gfx_v10_validate_trap_override_request(struct amdgpu_device *adev,
> +					     uint32_t trap_override,
> +					     uint32_t *trap_mask_supported);
> +uint32_t kgd_gfx_v10_set_wave_launch_trap_override(struct amdgpu_device *adev,
> +					     uint32_t vmid,
> +					     uint32_t trap_override,
> +					     uint32_t trap_mask_bits,
> +					     uint32_t trap_mask_request,
> +					     uint32_t *trap_mask_prev,
> +					     uint32_t kfd_dbg_trap_cntl_prev);
>   void kgd_gfx_v10_get_iq_wait_times(struct amdgpu_device *adev, uint32_t *wait_times);
>   void kgd_gfx_v10_build_grace_period_packet_info(struct amdgpu_device *adev,
>   					       uint32_t wait_times,
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10_3.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10_3.c
> index c57f2a6b6e23..ae3ead207df4 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10_3.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10_3.c
> @@ -673,5 +673,8 @@ const struct kfd2kgd_calls gfx_v10_3_kfd2kgd = {
>   	.get_iq_wait_times = kgd_gfx_v10_get_iq_wait_times,
>   	.build_grace_period_packet_info = kgd_gfx_v10_build_grace_period_packet_info,
>   	.enable_debug_trap = kgd_gfx_v10_enable_debug_trap,
> -	.disable_debug_trap = kgd_gfx_v10_disable_debug_trap
> +	.disable_debug_trap = kgd_gfx_v10_disable_debug_trap,
> +	.validate_trap_override_request = kgd_gfx_v10_validate_trap_override_request,
> +	.set_wave_launch_trap_override = kgd_gfx_v10_set_wave_launch_trap_override
> +
>   };
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v11.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v11.c
> index 34aeff692eba..3fb81e6e9422 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v11.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v11.c
> @@ -643,6 +643,88 @@ static uint32_t kgd_gfx_v11_disable_debug_trap(struct amdgpu_device *adev,
>   	return data;
>   }
>   
> +static int kgd_gfx_v11_validate_trap_override_request(struct amdgpu_device *adev,
> +							uint32_t trap_override,
> +							uint32_t *trap_mask_supported)
> +{
> +	*trap_mask_supported &= KFD_DBG_TRAP_MASK_FP_INVALID |
> +				KFD_DBG_TRAP_MASK_FP_INPUT_DENORMAL |
> +				KFD_DBG_TRAP_MASK_FP_DIVIDE_BY_ZERO |
> +				KFD_DBG_TRAP_MASK_FP_OVERFLOW |
> +				KFD_DBG_TRAP_MASK_FP_UNDERFLOW |
> +				KFD_DBG_TRAP_MASK_FP_INEXACT |
> +				KFD_DBG_TRAP_MASK_INT_DIVIDE_BY_ZERO |
> +				KFD_DBG_TRAP_MASK_DBG_ADDRESS_WATCH |
> +				KFD_DBG_TRAP_MASK_DBG_MEMORY_VIOLATION;
> +
> +	if (adev->ip_versions[GC_HWIP][0] >= IP_VERSION(11, 0, 4))
> +		*trap_mask_supported |= KFD_DBG_TRAP_MASK_TRAP_ON_WAVE_START |
> +					KFD_DBG_TRAP_MASK_TRAP_ON_WAVE_END;
> +
> +	if (trap_override != KFD_DBG_TRAP_OVERRIDE_OR &&
> +			trap_override != KFD_DBG_TRAP_OVERRIDE_REPLACE)
> +		return -EPERM;
> +
> +	return 0;
> +}
> +
> +static uint32_t trap_mask_map_sw_to_hw(uint32_t mask)
> +{
> +	uint32_t trap_on_start = (mask & KFD_DBG_TRAP_MASK_TRAP_ON_WAVE_START) ? 1 : 0;
> +	uint32_t trap_on_end = (mask & KFD_DBG_TRAP_MASK_TRAP_ON_WAVE_END) ? 1 : 0;
> +	uint32_t excp_en = mask & (KFD_DBG_TRAP_MASK_FP_INVALID |
> +			KFD_DBG_TRAP_MASK_FP_INPUT_DENORMAL |
> +			KFD_DBG_TRAP_MASK_FP_DIVIDE_BY_ZERO |
> +			KFD_DBG_TRAP_MASK_FP_OVERFLOW |
> +			KFD_DBG_TRAP_MASK_FP_UNDERFLOW |
> +			KFD_DBG_TRAP_MASK_FP_INEXACT |
> +			KFD_DBG_TRAP_MASK_INT_DIVIDE_BY_ZERO |
> +			KFD_DBG_TRAP_MASK_DBG_ADDRESS_WATCH |
> +			KFD_DBG_TRAP_MASK_DBG_MEMORY_VIOLATION);
> +	uint32_t ret;
> +
> +	ret = REG_SET_FIELD(0, SPI_GDBG_PER_VMID_CNTL, EXCP_EN, excp_en);
> +	ret = REG_SET_FIELD(ret, SPI_GDBG_PER_VMID_CNTL, TRAP_ON_START, trap_on_start);
> +	ret = REG_SET_FIELD(ret, SPI_GDBG_PER_VMID_CNTL, TRAP_ON_END, trap_on_end);
> +
> +	return ret;
> +}
> +
> +static uint32_t trap_mask_map_hw_to_sw(uint32_t mask)
> +{
> +	uint32_t ret = REG_GET_FIELD(mask, SPI_GDBG_PER_VMID_CNTL, EXCP_EN);
> +
> +	if (REG_GET_FIELD(mask, SPI_GDBG_PER_VMID_CNTL, TRAP_ON_START))
> +		ret |= KFD_DBG_TRAP_MASK_TRAP_ON_WAVE_START;
> +
> +	if (REG_GET_FIELD(mask, SPI_GDBG_PER_VMID_CNTL, TRAP_ON_END))
> +		ret |= KFD_DBG_TRAP_MASK_TRAP_ON_WAVE_END;
> +
> +	return ret;
> +}
> +
> +/* Returns TRAP_EN, EXCP_EN and EXCP_REPLACE. */
> +static uint32_t kgd_gfx_v11_set_wave_launch_trap_override(struct amdgpu_device *adev,
> +					uint32_t vmid,
> +					uint32_t trap_override,
> +					uint32_t trap_mask_bits,
> +					uint32_t trap_mask_request,
> +					uint32_t *trap_mask_prev,
> +					uint32_t kfd_dbg_trap_cntl_prev)
> +{
> +	uint32_t data = 0;
> +
> +	*trap_mask_prev = trap_mask_map_hw_to_sw(kfd_dbg_trap_cntl_prev);
> +
> +	data = (trap_mask_bits & trap_mask_request) | (*trap_mask_prev & ~trap_mask_request);
> +	data = trap_mask_map_sw_to_hw(data);
> +
> +	data = REG_SET_FIELD(data, SPI_GDBG_PER_VMID_CNTL, TRAP_EN, 1);
> +	data = REG_SET_FIELD(data, SPI_GDBG_PER_VMID_CNTL, EXCP_REPLACE, trap_override);
> +
> +	return data;
> +}
> +
>   const struct kfd2kgd_calls gfx_v11_kfd2kgd = {
>   	.program_sh_mem_settings = program_sh_mem_settings_v11,
>   	.set_pasid_vmid_mapping = set_pasid_vmid_mapping_v11,
> @@ -660,5 +742,7 @@ const struct kfd2kgd_calls gfx_v11_kfd2kgd = {
>   	.get_atc_vmid_pasid_mapping_info = NULL,
>   	.set_vm_context_page_table_base = set_vm_context_page_table_base_v11,
>   	.enable_debug_trap = kgd_gfx_v11_enable_debug_trap,
> -	.disable_debug_trap = kgd_gfx_v11_disable_debug_trap
> +	.disable_debug_trap = kgd_gfx_v11_disable_debug_trap,
> +	.validate_trap_override_request = kgd_gfx_v11_validate_trap_override_request,
> +	.set_wave_launch_trap_override = kgd_gfx_v11_set_wave_launch_trap_override
>   };
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.c
> index 4a8bd266d3f6..81643385512a 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.c
> @@ -38,6 +38,7 @@
>   #include "soc15d.h"
>   #include "gfx_v9_0.h"
>   #include "amdgpu_amdkfd_gfx_v9.h"
> +#include <uapi/linux/kfd_ioctl.h>
>   
>   enum hqd_dequeue_request_type {
>   	NO_ACTION = 0,
> @@ -737,6 +738,58 @@ uint32_t kgd_gfx_v9_disable_debug_trap(struct amdgpu_device *adev,
>   	return 0;
>   }
>   
> +int kgd_gfx_v9_validate_trap_override_request(struct amdgpu_device *adev,
> +					uint32_t trap_override,
> +					uint32_t *trap_mask_supported)
> +{
> +	*trap_mask_supported &= KFD_DBG_TRAP_MASK_DBG_ADDRESS_WATCH;
> +
> +	/* The SPI_GDBG_TRAP_MASK register is global and affects all
> +	 * processes. Only allow OR-ing the address-watch bit, since
> +	 * this only affects processes under the debugger. Other bits
> +	 * should stay 0 to avoid the debugger interfering with other
> +	 * processes.
> +	 */
> +	if (trap_override != KFD_DBG_TRAP_OVERRIDE_OR)
> +		return -EINVAL;
> +
> +	return 0;
> +}
> +
> +uint32_t kgd_gfx_v9_set_wave_launch_trap_override(struct amdgpu_device *adev,
> +					     uint32_t vmid,
> +					     uint32_t trap_override,
> +					     uint32_t trap_mask_bits,
> +					     uint32_t trap_mask_request,
> +					     uint32_t *trap_mask_prev,
> +					     uint32_t kfd_dbg_cntl_prev)
> +{
> +	uint32_t data, wave_cntl_prev;
> +
> +	mutex_lock(&adev->grbm_idx_mutex);
> +
> +	wave_cntl_prev = RREG32(SOC15_REG_OFFSET(GC, 0, mmSPI_GDBG_WAVE_CNTL));
> +
> +	kgd_gfx_v9_set_wave_launch_stall(adev, vmid, true);
> +
> +	data = RREG32(SOC15_REG_OFFSET(GC, 0, mmSPI_GDBG_TRAP_MASK));
> +	*trap_mask_prev = REG_GET_FIELD(data, SPI_GDBG_TRAP_MASK, EXCP_EN);
> +
> +	trap_mask_bits = (trap_mask_bits & trap_mask_request) |
> +		(*trap_mask_prev & ~trap_mask_request);
> +
> +	data = REG_SET_FIELD(data, SPI_GDBG_TRAP_MASK, EXCP_EN, trap_mask_bits);
> +	data = REG_SET_FIELD(data, SPI_GDBG_TRAP_MASK, REPLACE, trap_override);
> +	WREG32(SOC15_REG_OFFSET(GC, 0, mmSPI_GDBG_TRAP_MASK), data);
> +
> +	/* We need to preserve wave launch mode stall settings. */
> +	WREG32(SOC15_REG_OFFSET(GC, 0, mmSPI_GDBG_WAVE_CNTL), wave_cntl_prev);
> +
> +	mutex_unlock(&adev->grbm_idx_mutex);
> +
> +	return 0;
> +}
> +
>   /* kgd_gfx_v9_get_iq_wait_times: Returns the mmCP_IQ_WAIT_TIME1/2 values
>    * The values read are:
>    *     ib_offload_wait_time     -- Wait Count for Indirect Buffer Offloads.
> @@ -1005,6 +1058,8 @@ const struct kfd2kgd_calls gfx_v9_kfd2kgd = {
>   	.set_vm_context_page_table_base = kgd_gfx_v9_set_vm_context_page_table_base,
>   	.enable_debug_trap = kgd_gfx_v9_enable_debug_trap,
>   	.disable_debug_trap = kgd_gfx_v9_disable_debug_trap,
> +	.validate_trap_override_request = kgd_gfx_v9_validate_trap_override_request,
> +	.set_wave_launch_trap_override = kgd_gfx_v9_set_wave_launch_trap_override,
>   	.get_iq_wait_times = kgd_gfx_v9_get_iq_wait_times,
>   	.build_grace_period_packet_info = kgd_gfx_v9_build_grace_period_packet_info,
>   	.get_cu_occupancy = kgd_gfx_v9_get_cu_occupancy,
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.h
> index c0866497cb5c..47cff392b434 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.h
> @@ -64,6 +64,16 @@ uint32_t kgd_gfx_v9_enable_debug_trap(struct amdgpu_device *adev,
>   uint32_t kgd_gfx_v9_disable_debug_trap(struct amdgpu_device *adev,
>   					bool keep_trap_enabled,
>   					uint32_t vmid);
> +int kgd_gfx_v9_validate_trap_override_request(struct amdgpu_device *adev,
> +					     uint32_t trap_override,
> +					     uint32_t *trap_mask_supported);
> +uint32_t kgd_gfx_v9_set_wave_launch_trap_override(struct amdgpu_device *adev,
> +					     uint32_t vmid,
> +					     uint32_t trap_override,
> +					     uint32_t trap_mask_bits,
> +					     uint32_t trap_mask_request,
> +					     uint32_t *trap_mask_prev,
> +					     uint32_t kfd_dbg_trap_cntl_prev);
>   void kgd_gfx_v9_get_iq_wait_times(struct amdgpu_device *adev, uint32_t *wait_times);
>   void kgd_gfx_v9_build_grace_period_packet_info(struct amdgpu_device *adev,
>   					       uint32_t wait_times,
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
> index 9b87ba351eff..28b9db5806f4 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
> @@ -2896,6 +2896,13 @@ static int kfd_ioctl_set_debug_trap(struct file *filep, struct kfd_process *p, v
>   				args->set_exceptions_enabled.exception_mask);
>   		break;
>   	case KFD_IOC_DBG_TRAP_SET_WAVE_LAUNCH_OVERRIDE:
> +		r = kfd_dbg_trap_set_wave_launch_override(target,
> +				args->launch_override.override_mode,
> +				args->launch_override.enable_mask,
> +				args->launch_override.support_request_mask,
> +				&args->launch_override.enable_mask,
> +				&args->launch_override.support_request_mask);
> +		break;
>   	case KFD_IOC_DBG_TRAP_SET_WAVE_LAUNCH_MODE:
>   	case KFD_IOC_DBG_TRAP_SUSPEND_QUEUES:
>   	case KFD_IOC_DBG_TRAP_RESUME_QUEUES:
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_debug.c b/drivers/gpu/drm/amd/amdkfd/kfd_debug.c
> index 3ea53aaa776b..a9b52f114ac6 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_debug.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_debug.c
> @@ -530,6 +530,75 @@ int kfd_dbg_trap_enable(struct kfd_process *target, uint32_t fd,
>   	return r;
>   }
>   
> +static int kfd_dbg_validate_trap_override_request(struct kfd_process *p,
> +						uint32_t trap_override,
> +						uint32_t trap_mask_request,
> +						uint32_t *trap_mask_supported)
> +{
> +	int i = 0;
> +
> +	*trap_mask_supported = 0xffffffff;
> +
> +	for (i = 0; i < p->n_pdds; i++) {
> +		struct kfd_process_device *pdd = p->pdds[i];
> +		int err = pdd->dev->kfd2kgd->validate_trap_override_request(
> +								pdd->dev->adev,
> +								trap_override,
> +								trap_mask_supported);
> +
> +		if (err)
> +			return err;
> +	}
> +
> +	if (trap_mask_request & ~*trap_mask_supported)
> +		return -EACCES;
> +
> +	return 0;
> +}
> +
> +int kfd_dbg_trap_set_wave_launch_override(struct kfd_process *target,
> +					uint32_t trap_override,
> +					uint32_t trap_mask_bits,
> +					uint32_t trap_mask_request,
> +					uint32_t *trap_mask_prev,
> +					uint32_t *trap_mask_supported)
> +{
> +	int r = 0, i;
> +
> +	r = kfd_dbg_validate_trap_override_request(target,
> +						trap_override,
> +						trap_mask_request,
> +						trap_mask_supported);
> +
> +	if (r)
> +		return r;
> +
> +	for (i = 0; i < target->n_pdds; i++) {
> +		struct kfd_process_device *pdd = target->pdds[i];
> +
> +		amdgpu_gfx_off_ctrl(pdd->dev->adev, false);

I think the gfxoff stuff is not needed on HW that supports multi-process 
debugging because these functions don't touch HW registers in that case. 
I think the gfxoff stuff should be done in the HW-specific functions 
only if needed. Maybe that comment applies to more patches than just 
this one. It's an improvement we could do in a follow up to make sure 
we're not missing any cases.

The patch is

Reviewed-by: Felix Kuehling <Felix.Kuehling@xxxxxxx>


> +		pdd->spi_dbg_override = pdd->dev->kfd2kgd->set_wave_launch_trap_override(
> +				pdd->dev->adev,
> +				pdd->dev->vm_info.last_vmid_kfd,
> +				trap_override,
> +				trap_mask_bits,
> +				trap_mask_request,
> +				trap_mask_prev,
> +				pdd->spi_dbg_override);
> +		amdgpu_gfx_off_ctrl(pdd->dev->adev, true);
> +
> +		if (!pdd->dev->shared_resources.enable_mes)
> +			r = debug_refresh_runlist(pdd->dev->dqm);
> +		else
> +			r = kfd_dbg_set_mes_debug_mode(pdd);
> +
> +		if (r)
> +			break;
> +	}
> +
> +	return r;
> +}
> +
>   void kfd_dbg_set_enabled_debug_exception_mask(struct kfd_process *target,
>   					uint64_t exception_set_mask)
>   {
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_debug.h b/drivers/gpu/drm/amd/amdkfd/kfd_debug.h
> index 81557579ab04..864eb01f8973 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_debug.h
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_debug.h
> @@ -45,6 +45,12 @@ int kfd_dbg_trap_disable(struct kfd_process *target);
>   int kfd_dbg_trap_enable(struct kfd_process *target, uint32_t fd,
>   			void __user *runtime_info,
>   			uint32_t *runtime_info_size);
> +int kfd_dbg_trap_set_wave_launch_override(struct kfd_process *target,
> +					uint32_t trap_override,
> +					uint32_t trap_mask_bits,
> +					uint32_t trap_mask_request,
> +					uint32_t *trap_mask_prev,
> +					uint32_t *trap_mask_supported);
>   
>   int kfd_dbg_send_exception_to_runtime(struct kfd_process *p,
>   					unsigned int dev_id,