This flag was never meant for user mode. Alex ended up implementing it
differently in a way that doesn't need to change the flags exposed to
user mode. See his patch "drm/amdkfd: flag added to handle errors from
svm validate and map". This patch is no longer needed.
Regards,
Felix
Am 2023-05-31 um 10:09 schrieb Deucher, Alexander:
[Public]
Where is the userspace code which uses this new interface? Can you add
a link to the relevant branch to the commit message?
Alex
------------------------------------------------------------------------
*From:* amd-gfx <amd-gfx-bounces@xxxxxxxxxxxxxxxxxxxxx> on behalf of
Alex Sierra <alex.sierra@xxxxxxx>
*Sent:* Monday, May 29, 2023 4:09 PM
*To:* amd-gfx@xxxxxxxxxxxxxxxxxxxxx <amd-gfx@xxxxxxxxxxxxxxxxxxxxx>;
Kuehling, Felix <Felix.Kuehling@xxxxxxx>
*Cc:* Sierra Guiza, Alejandro (Alex) <Alex.Sierra@xxxxxxx>; Yang,
Philip <Philip.Yang@xxxxxxx>
*Subject:* [PATCH] drm/amd: SVM flag error added at svm_range flags
If a return error is raised during validation and mapping of a
prange, this flag is set. It is a rare occurrence, but it could happen
when `amdgpu_hmm_range_get_pages_done` returns true. In such cases,
the caller should retry. However, it is important to ensure that the
prange is updated correctly during the retry.
Signed-off-by: Alex Sierra <alex.sierra@xxxxxxx>
---
drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 12 +++++++++++-
include/uapi/linux/kfd_ioctl.h | 2 ++
2 files changed, 13 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index fcfde9140bce..96abae515bcf 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -756,10 +756,12 @@ svm_range_apply_attrs(struct kfd_process *p,
struct svm_range *prange,
break;
case KFD_IOCTL_SVM_ATTR_SET_FLAGS:
*update_mapping = true;
+ attrs[i].value &= ~KFD_IOCTL_SVM_FLAG_ERROR;
prange->flags |= attrs[i].value;
break;
case KFD_IOCTL_SVM_ATTR_CLR_FLAGS:
*update_mapping = true;
+ attrs[i].value &= ~KFD_IOCTL_SVM_FLAG_ERROR;
prange->flags &= ~attrs[i].value;
break;
case KFD_IOCTL_SVM_ATTR_GRANULARITY:
@@ -778,6 +780,9 @@ svm_range_is_same_attrs(struct kfd_process *p,
struct svm_range *prange,
uint32_t i;
int gpuidx;
+ if (prange->flags & KFD_IOCTL_SVM_FLAG_ERROR)
+ return false;
+
for (i = 0; i < nattr; i++) {
switch (attrs[i].type) {
case KFD_IOCTL_SVM_ATTR_PREFERRED_LOC:
@@ -1657,8 +1662,11 @@ static int svm_range_validate_and_map(struct
mm_struct *mm,
unreserve_out:
svm_range_unreserve_bos(&ctx);
- if (!r)
+ prange->flags |= KFD_IOCTL_SVM_FLAG_ERROR;
+ if (!r) {
+ prange->flags &= ~KFD_IOCTL_SVM_FLAG_ERROR;
prange->validate_timestamp = ktime_get_boottime();
+ }
return r;
}
@@ -3674,9 +3682,11 @@ svm_range_get_attr(struct kfd_process *p,
struct mm_struct *mm,
break;
case KFD_IOCTL_SVM_ATTR_SET_FLAGS:
attrs[i].value = flags_and;
+ attrs[i].value &= ~KFD_IOCTL_SVM_FLAG_ERROR;
break;
case KFD_IOCTL_SVM_ATTR_CLR_FLAGS:
attrs[i].value = ~flags_or;
+ attrs[i].value &= ~KFD_IOCTL_SVM_FLAG_ERROR;
break;
case KFD_IOCTL_SVM_ATTR_GRANULARITY:
attrs[i].value = (uint32_t)granularity;
diff --git a/include/uapi/linux/kfd_ioctl.h
b/include/uapi/linux/kfd_ioctl.h
index 7e19a2d1e907..2b6f68bd06da 100644
--- a/include/uapi/linux/kfd_ioctl.h
+++ b/include/uapi/linux/kfd_ioctl.h
@@ -1125,6 +1125,8 @@ struct kfd_ioctl_cross_memory_copy_deprecated_args {
#define KFD_IOCTL_SVM_FLAG_GPU_READ_MOSTLY 0x00000020
/* Keep GPU memory mapping always valid as if XNACK is disable */
#define KFD_IOCTL_SVM_FLAG_GPU_ALWAYS_MAPPED 0x00000040
+/* Set during svm validation and map error */
+#define KFD_IOCTL_SVM_FLAG_ERROR 0x80000000
/**
* kfd_ioctl_svm_op - SVM ioctl operations
--
2.32.0
