[PATCH v1 2/2] drm/amdgpu: adding device coredump support
Somalapuram, Amaranath
asomalap at amd.com
Tue May 24 13:18:07 UTC 2022
On 5/24/2022 6:20 PM, Sharma, Shashank wrote:
>
>
> On 5/24/2022 2:10 PM, Somalapuram, Amaranath wrote:
>>
>> On 5/24/2022 3:23 PM, Sharma, Shashank wrote:
>>>
>>>
>>> On 5/24/2022 8:42 AM, Somalapuram, Amaranath wrote:
>>>>
>>>> On 5/20/2022 7:52 PM, Sharma, Shashank wrote:
>>>>>
>>>>>
>>>>> On 5/20/2022 3:49 PM, Somalapuram Amaranath wrote:
>>>>>> Added device coredump information:
>>>>>> - Kernel version
>>>>>> - Module
>>>>>> - Time
>>>>>> - VRAM status
>>>>>> - Guilty process name and PID
>>>>>> - GPU register dumps
>>>>>>
>>>>>> Signed-off-by: Somalapuram Amaranath <Amaranath.Somalapuram at amd.com>
>>>>>> ---
>>>>>> drivers/gpu/drm/amd/amdgpu/amdgpu.h | 3 ++
>>>>>> drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 59
>>>>>> ++++++++++++++++++++++
>>>>>> 2 files changed, 62 insertions(+)
>>>>>>
>>>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>>>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>>>>>> index c79d9992b113..f28d9c563f74 100644
>>>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>>>>>> @@ -1044,6 +1044,9 @@ struct amdgpu_device {
>>>>>> uint32_t *reset_dump_reg_list;
>>>>>> uint32_t *reset_dump_reg_value;
>>>>>> int num_regs;
>>>>>> + struct amdgpu_task_info reset_context_task_info;
>>>>>> + bool reset_context_vram_lost;
>>>>>
>>>>> How about drop the 'context' from name and just reset_task_info
>>>>> and reset_vram_lost ?
>>>> OK.
>>>>>
>>>>>> + struct timespec64 reset_time;
>>>>>> struct amdgpu_reset_domain *reset_domain;
>>>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>>>>> index 963c897a76e6..f9b710e741a7 100644
>>>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>>>>> @@ -32,6 +32,8 @@
>>>>>> #include <linux/slab.h>
>>>>>> #include <linux/iommu.h>
>>>>>> #include <linux/pci.h>
>>>>>> +#include <linux/devcoredump.h>
>>>>>> +#include <generated/utsrelease.h>
>>>>>> #include <drm/drm_atomic_helper.h>
>>>>>> #include <drm/drm_probe_helper.h>
>>>>>> @@ -4733,6 +4735,55 @@ static int amdgpu_reset_reg_dumps(struct
>>>>>> amdgpu_device *adev)
>>>>>> return 0;
>>>>>> }
>>>>>> +#ifdef CONFIG_DEV_COREDUMP
>>>>>> +static ssize_t amdgpu_devcoredump_read(char *buffer, loff_t offset,
>>>>>> + size_t count, void *data, size_t datalen)
>>>>>> +{
>>>>>> + struct drm_printer p;
>>>>>> + struct amdgpu_device *adev = data;
>>>>>> + struct drm_print_iterator iter;
>>>>>> + int i;
>>>>>> +
>>>>>
>>>>> A NULL check for 'buffer' here could prevent a segfault later.
>>>>>
>>>> Agreed.
>>>>>> + iter.data = buffer;
>>>>>> + iter.offset = 0;
>>>>>> + iter.start = offset;
>>>>>> + iter.remain = count;
>>>>>> +
>>>>>> + p = drm_coredump_printer(&iter);
>>>>>> +
>>>>>> + drm_printf(&p, "**** AMDGPU Device Coredump ****\n");
>>>>>> + drm_printf(&p, "kernel: " UTS_RELEASE "\n");
>>>>>> + drm_printf(&p, "module: " KBUILD_MODNAME "\n");
>>>>>> + drm_printf(&p, "time: %lld.%09ld\n",
>>>>>> adev->reset_time.tv_sec, adev->reset_time.tv_nsec);
>>>>>> + if (adev->reset_context_task_info.pid)
>>>>>> + drm_printf(&p, "process_name: %s PID: %d\n",
>>>>>> + adev->reset_context_task_info.process_name,
>>>>>> + adev->reset_context_task_info.pid);
>>>>> Please fix the alignment of print variables.
>>>>>
>>>> I will cross check this.
>>>>>> +
>>>>>> + if (adev->reset_context_vram_lost)
>>>>>> + drm_printf(&p, "VRAM is lost due to GPU reset!\n");
>>>>>> + if (adev->num_regs) {
>>>>>> + drm_printf(&p, "AMDGPU register dumps:\nOffset: Value:\n");
>>>>>> +
>>>>>> + for (i = 0; i < adev->num_regs; i++)
>>>>>> + drm_printf(&p, "0x%08x: 0x%08x\n",
>>>>>> + adev->reset_dump_reg_list[i],
>>>>>> + adev->reset_dump_reg_value[i]);
>>>>>> + }
>>>>>> +
>>>>>> + return count - iter.remain;
>>>>>> +}
>>>>>> +
>>>>>> +static void amdgpu_reset_capture_coredumpm(struct amdgpu_device
>>>>>> *adev)
>>>>>> +{
>>>>>> + struct drm_device *dev = adev_to_drm(adev);
>>>>>> +
>>>>>> + ktime_get_ts64(&adev->reset_time);
>>>>>> + dev_coredumpm(dev->dev, THIS_MODULE, adev, 0, GFP_KERNEL,
>>>>>> + amdgpu_devcoredump_read, NULL);
>>>>> instead of registering NULL as free function, I would prefer you
>>>>> to have a dummy no_op free function registered, which we can
>>>>> consume if something changes.
>>>> you mean something like this (function without any code):
>>>> staticvoidamdgpu_devcoredump_free(void*data)
>>>> {
>>>> }
>>>
>>> Yes, precisely.
>>>
>>>>>> +}
>>>>>> +#endif
>>>>>> +
>>>>>> int amdgpu_do_asic_reset(struct list_head *device_list_handle,
>>>>>> struct amdgpu_reset_context *reset_context)
>>>>>> {
>>>>>> @@ -4817,6 +4868,14 @@ int amdgpu_do_asic_reset(struct list_head
>>>>>> *device_list_handle,
>>>>>> goto out;
>>>>>> vram_lost =
>>>>>> amdgpu_device_check_vram_lost(tmp_adev);
>>>>>> +#ifdef CONFIG_DEV_COREDUMP
>>>>>> + tmp_adev->reset_context_vram_lost = vram_lost;
>>>>>> + tmp_adev->reset_context_task_info.pid = 0;
>>>>> why is the PID hardcoded to 0 ?
>>>> in case of reset context reset_context->job->vm is null
>>>> (possibility that reset can be non VM related).
>>>> If we don't set tmp_adev->reset_context_task_info.pid = 0, it will
>>>> show previous reset valid PID.
>>>>
>>>
>>> But when the VM is not NULL, are we updating this PID somewhere ? I
>>> did not see that happening in this series.
>> This is the only place where PID get updated.
>> For example sequence of operation like:
>> 1st reset:
>> -valid VM and tmp_adev->reset_context_task_info.pid is set to some
>> valid PID
>> 2nd reset:
>> -invalid VM
>> -tmp_adev context will remain same (adev context will be same after
>> successful GPU reset sequence).
>> -tmp_adev->reset_context_task_info.pid will be holding 1st reset PID
>> value
>>
>> if we don't set it 0, it can give wrong PID.
>>
>
> I get your point, and agree, that when the vm is invalid, PID is
> invalid so we should send pid=0. But where are you handling the case
> when VM is valid and pid is valid ?
valid VM check in the below condition:
-->if (reset_context->job && reset_context->job->vm)
reset_context->job->vm->task_info will have the required information.
>
> - Shashank
>
>> Regards,
>> S.Amarnath
>>>
>>> - Shashank
>>>
>>>>
>>>> Regards,
>>>> S.Amarnath
>>>>>> + if (reset_context->job && reset_context->job->vm)
>>>>>> + tmp_adev->reset_context_task_info =
>>>>>> + reset_context->job->vm->task_info;
>>>>>> + amdgpu_reset_capture_coredumpm(tmp_adev);
>>>>>> +#endif
>>>>>> if (vram_lost) {
>>>>>> DRM_INFO("VRAM is lost due to GPU reset!\n");
>>>>>>
>>>>> - Shashank
>>>>> amdgpu_inc_vram_lost(tmp_adev);
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