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<div dir="ltr" id="divRplyFwdMsg"><span style="font-family: Calibri, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);"><b>From:</b> Cavitt, Jonathan <jonathan.cavitt@intel.com><br>
<b>Sent:</b> Friday, February 28, 2025 10:21 AM<br>
<b>To:</b> intel-xe@lists.freedesktop.org <intel-xe@lists.freedesktop.org><br>
<b>Cc:</b> Gupta, saurabhg <saurabhg.gupta@intel.com>; Zuo, Alex <alex.zuo@intel.com>; Cavitt, Jonathan <jonathan.cavitt@intel.com>; joonas.lahtinen@linux.intel.com <joonas.lahtinen@linux.intel.com>; Brost, Matthew <matthew.brost@intel.com>; Zhang, Jianxun
 <jianxun.zhang@intel.com>; dri-devel@lists.freedesktop.org <dri-devel@lists.freedesktop.org><br>
<b>Subject:</b> [PATCH v3 6/6] drm/xe/xe_vm: Implement xe_vm_get_property_ioctl</span>
<div> </div>
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<div class="elementToProof" style="font-size: 11pt;">Add support for userspace to request a list of observed failed<br>
pagefaults from a specified VM.<br>
<br>
v2:<br>
- Only allow querying of failed pagefaults (Matt Brost)<br>
<br>
Signed-off-by: Jonathan Cavitt <jonathan.cavitt@intel.com><br>
Suggested-by: Matthew Brost <matthew.brost@intel.com><br>
---<br>
 drivers/gpu/drm/xe/xe_device.c |  3 ++<br>
 drivers/gpu/drm/xe/xe_vm.c     | 79 ++++++++++++++++++++++++++++++++++<br>
 drivers/gpu/drm/xe/xe_vm.h     |  2 +<br>
 3 files changed, 84 insertions(+)<br>
<br>
diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c<br>
index 9454b51f7ad8..43accae152ff 100644<br>
--- a/drivers/gpu/drm/xe/xe_device.c<br>
+++ b/drivers/gpu/drm/xe/xe_device.c<br>
@@ -193,6 +193,9 @@ static const struct drm_ioctl_desc xe_ioctls[] = {<br>
         DRM_IOCTL_DEF_DRV(XE_WAIT_USER_FENCE, xe_wait_user_fence_ioctl,<br>
                           DRM_RENDER_ALLOW),<br>
         DRM_IOCTL_DEF_DRV(XE_OBSERVATION, xe_observation_ioctl, DRM_RENDER_ALLOW),<br>
+       DRM_IOCTL_DEF_DRV(XE_VM_GET_PROPERTY, xe_vm_get_property_ioctl,<br>
+                         DRM_RENDER_ALLOW),<br>
+<br>
 };<br>
 <br>
 static long xe_drm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)<br>
diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c<br>
index 6211b971bbbd..00d2c62ccf53 100644<br>
--- a/drivers/gpu/drm/xe/xe_vm.c<br>
+++ b/drivers/gpu/drm/xe/xe_vm.c<br>
@@ -3234,6 +3234,85 @@ int xe_vm_bind_ioctl(struct drm_device *dev, void *data, struct drm_file *file)<br>
         return err;<br>
 }<br>
 <br>
+static u32 xe_vm_get_property_size(struct xe_vm *vm, u32 property)<br>
+{<br>
+       u32 size = 0;<br>
+<br>
+       switch (property) {<br>
+       case DRM_XE_VM_GET_PROPERTY_FAULTS:<br>
+               spin_lock(&vm->pfs.lock);<br>
+               size = vm->pfs.len * sizeof(struct drm_xe_pf);</div>
<div class="elementToProof" style="font-size: 11pt;">+               spin_unlock(&vm->pfs.lock);<br>
+               return size;<br>
+       default:<br>
+               return -EINVAL;<br>
+       }<br>
+}<br>
+<br>
+static int fill_property_pfs(struct xe_vm *vm,<br>
+                            struct drm_xe_vm_get_property *args,<br>
+                            u32 size)<br>
+{<br>
+       struct drm_xe_pf __user *usr_ptr = u64_to_user_ptr(args->ptr);<br>
+       struct drm_xe_pf *fault_list;<br>
+       struct drm_xe_pf *fault;<br>
+       struct xe_vm_pf_entry *entry;<br>
+       int i = 0;<br>
+<br>
+       if (copy_from_user(&fault_list, usr_ptr, size))<br>
+               return -EFAULT;</div>
<div class="elementToProof" style="font-size: 11pt;">Why is copying from user space memory needed in this query ioctl?</div>
<div class="elementToProof" style="font-size: 11pt;"><br>
</div>
<div class="elementToProof" style="font-size: 11pt;">Does copy_from_<span style="color: rgb(0, 0, 0);">user() automatically allocate kernel memory for
</span><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; color: rgb(0, 0, 0);">fault_list?</span></div>
<div class="elementToProof" style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);">
<br>
</div>
<div class="elementToProof" style="font-size: 11pt;">+<br>
+       spin_lock(&vm->pfs.lock);<br>
+       list_for_each_entry(entry, &vm->pfs.list, list) {<br>
+               struct xe_pagefault *pf = entry->pf;<br>
+<br>
+               fault = &fault_list[i++];<br>
+               fault->address = pf->page_addr;<br>
+               fault->address_type = pf->address_type;<br>
+               fault->address_precision = SZ_4K;</div>
<div class="elementToProof" style="font-size: 11pt;">If we can get the exact address, the precision should be 1, right? (<span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; color: rgb(0, 0, 0);"><a href="https://registry.khronos.org/vulkan/specs/latest/man/html/VkDeviceFaultAddressInfoEXT.html" id="LPlnk590013">https://registry.khronos.org/vulkan/specs/latest/man/html/VkDeviceFaultAddressInfoEXT.html</a>)</span></div>
<div class="elementToProof" style="font-size: 11pt;"><br>
+       }<br>
+       spin_unlock(&vm->pfs.lock);<br>
+<br>
+       if (copy_to_user(usr_ptr, &fault_list, size))<br>
+               return -EFAULT;<br>
+<br>
+       return 0;<br>
+}<br>
+<br>
+int xe_vm_get_property_ioctl(struct drm_device *drm, void *data,<br>
+                            struct drm_file *file)<br>
+{<br>
+       struct xe_device *xe = to_xe_device(drm);<br>
+       struct xe_file *xef = to_xe_file(file);<br>
+       struct drm_xe_vm_get_property *args = data;<br>
+       struct xe_vm *vm;<br>
+       u32 size;<br>
+<br>
+       if (XE_IOCTL_DBG(xe, args->reserved[0] || args->reserved[1]))<br>
+               return -EINVAL;<br>
+<br>
+       vm = xe_vm_lookup(xef, args->vm_id);<br>
+       if (XE_IOCTL_DBG(xe, !vm))<br>
+               return -ENOENT;<br>
+<br>
+       size = xe_vm_get_property_size(vm, args->property);<br>
+       if (size < 0) {<br>
+               return size;<br>
+       } else if (args->size != size) {<br>
+               if (args->size)<br>
+                       return -EINVAL;</div>
<div class="elementToProof" style="font-size: 11pt; color: rgb(0, 0, 0);">If there is a change in the size of property between the first and the second calls, say, more faults added in this case, the 2<sup>nd</sup> call will fail unintendedly. </div>
<div class="elementToProof" style="font-size: 11pt;">+               args->size = size;</div>
<div class="elementToProof" style="font-size: 11pt; color: rgb(0, 0, 0);">​+               return 0;<br>
+       }<br>
+<br>
+       switch (args->property) {<br>
+       case DRM_XE_VM_GET_PROPERTY_FAULTS:<br>
+               return fill_property_pfs(vm, args, size);<br>
+       default:<br>
+               return -EINVAL;<br>
+       }<br>
+}<br>
+<br>
 /**<br>
  * xe_vm_bind_kernel_bo - bind a kernel BO to a VM<br>
  * @vm: VM to bind the BO to<br>
diff --git a/drivers/gpu/drm/xe/xe_vm.h b/drivers/gpu/drm/xe/xe_vm.h<br>
index 4d94ab5c8ea4..bf6604465aa3 100644<br>
--- a/drivers/gpu/drm/xe/xe_vm.h<br>
+++ b/drivers/gpu/drm/xe/xe_vm.h<br>
@@ -184,6 +184,8 @@ int xe_vm_destroy_ioctl(struct drm_device *dev, void *data,<br>
                         struct drm_file *file);<br>
 int xe_vm_bind_ioctl(struct drm_device *dev, void *data,<br>
                      struct drm_file *file);<br>
+int xe_vm_get_property_ioctl(struct drm_device *dev, void *data,<br>
+                            struct drm_file *file);<br>
 <br>
 void xe_vm_close_and_put(struct xe_vm *vm);<br>
 <br>
--<br>
2.43.0<br>
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