On 26/05/2022 08:58, Tvrtko Ursulin wrote:
On 25/05/2022 19:43, Matthew Auld wrote:
Vulkan would like to have a rough measure of how much device memory can in theory be allocated. Also add unallocated_cpu_visible_size to track the visible portion, in case the device is using small BAR.
I have concerns here that it isn't useful and could even be counter-productive. If we give unprivileged access it may be considered a side channel, but if we "lie" (report total region size) to unprivileged clients (like in this patch), then they don't co-operate well and end trashing.
Is Vulkan really sure it wants this and why?
Lionel pointed out: https://www.khronos.org/registry/vulkan/specs/1.3-extensions/man/html/VK_EXT...
Also note that the existing behaviour was to lie. I'm not sure what's the best option here.
Regards,
Tvrtko
Testcase: igt@i915_query@query-regions-unallocated Testcase: igt@i915_query@query-regions-sanity-check Signed-off-by: Matthew Auld matthew.auld@intel.com Cc: Thomas Hellström thomas.hellstrom@linux.intel.com Cc: Lionel Landwerlin lionel.g.landwerlin@intel.com Cc: Tvrtko Ursulin tvrtko.ursulin@linux.intel.com Cc: Jon Bloomfield jon.bloomfield@intel.com Cc: Daniel Vetter daniel.vetter@ffwll.ch Cc: Jordan Justen jordan.l.justen@intel.com Cc: Kenneth Graunke kenneth@whitecape.org Cc: Akeem G Abodunrin akeem.g.abodunrin@intel.com
drivers/gpu/drm/i915/i915_query.c | 10 +++++- drivers/gpu/drm/i915/i915_ttm_buddy_manager.c | 20 ++++++++++++ drivers/gpu/drm/i915/i915_ttm_buddy_manager.h | 3 ++ drivers/gpu/drm/i915/intel_memory_region.c | 14 +++++++++ drivers/gpu/drm/i915/intel_memory_region.h | 3 ++ include/uapi/drm/i915_drm.h | 31 ++++++++++++++++++- 6 files changed, 79 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_query.c b/drivers/gpu/drm/i915/i915_query.c index 9aa0b28aa6ee..e095c55f4d4b 100644 --- a/drivers/gpu/drm/i915/i915_query.c +++ b/drivers/gpu/drm/i915/i915_query.c @@ -502,7 +502,15 @@ static int query_memregion_info(struct drm_i915_private *i915, else info.probed_cpu_visible_size = mr->total; - info.unallocated_size = mr->avail; + if (perfmon_capable()) { + intel_memory_region_avail(mr, + &info.unallocated_size, + &info.unallocated_cpu_visible_size); + } else { + info.unallocated_size = info.probed_size; + info.unallocated_cpu_visible_size = + info.probed_cpu_visible_size; + } if (__copy_to_user(info_ptr, &info, sizeof(info))) return -EFAULT; diff --git a/drivers/gpu/drm/i915/i915_ttm_buddy_manager.c b/drivers/gpu/drm/i915/i915_ttm_buddy_manager.c index a5109548abc0..aa5c91e44438 100644 --- a/drivers/gpu/drm/i915/i915_ttm_buddy_manager.c +++ b/drivers/gpu/drm/i915/i915_ttm_buddy_manager.c @@ -365,6 +365,26 @@ u64 i915_ttm_buddy_man_visible_size(struct ttm_resource_manager *man) return bman->visible_size; } +/**
- i915_ttm_buddy_man_visible_size - Query the avail tracking for the
manager.
- @man: The buddy allocator ttm manager
- @avail: The total available memory in pages for the entire manager.
- @visible_avail: The total available memory in pages for the CPU
visible
- portion. Note that this will always give the same value as @avail on
- configurations that don't have a small BAR.
- */
+void i915_ttm_buddy_man_avail(struct ttm_resource_manager *man, + u64 *avail, u64 *visible_avail) +{ + struct i915_ttm_buddy_manager *bman = to_buddy_manager(man);
+ mutex_lock(&bman->lock); + *avail = bman->mm.avail >> PAGE_SHIFT; + *visible_avail = bman->visible_avail; + mutex_unlock(&bman->lock); +}
#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST) void i915_ttm_buddy_man_force_visible_size(struct ttm_resource_manager *man, u64 size) diff --git a/drivers/gpu/drm/i915/i915_ttm_buddy_manager.h b/drivers/gpu/drm/i915/i915_ttm_buddy_manager.h index 52d9586d242c..d64620712830 100644 --- a/drivers/gpu/drm/i915/i915_ttm_buddy_manager.h +++ b/drivers/gpu/drm/i915/i915_ttm_buddy_manager.h @@ -61,6 +61,9 @@ int i915_ttm_buddy_man_reserve(struct ttm_resource_manager *man, u64 i915_ttm_buddy_man_visible_size(struct ttm_resource_manager *man); +void i915_ttm_buddy_man_avail(struct ttm_resource_manager *man, + u64 *avail, u64 *avail_visible);
#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST) void i915_ttm_buddy_man_force_visible_size(struct ttm_resource_manager *man, u64 size); diff --git a/drivers/gpu/drm/i915/intel_memory_region.c b/drivers/gpu/drm/i915/intel_memory_region.c index e38d2db1c3e3..94ee26e99549 100644 --- a/drivers/gpu/drm/i915/intel_memory_region.c +++ b/drivers/gpu/drm/i915/intel_memory_region.c @@ -279,6 +279,20 @@ void intel_memory_region_set_name(struct intel_memory_region *mem, va_end(ap); } +void intel_memory_region_avail(struct intel_memory_region *mr, + u64 *avail, u64 *visible_avail) +{ + if (mr->type == INTEL_MEMORY_LOCAL) { + i915_ttm_buddy_man_avail(mr->region_private, + avail, visible_avail); + *avail <<= PAGE_SHIFT; + *visible_avail <<= PAGE_SHIFT; + } else { + *avail = mr->total; + *visible_avail = mr->total; + } +}
void intel_memory_region_destroy(struct intel_memory_region *mem) { int ret = 0; diff --git a/drivers/gpu/drm/i915/intel_memory_region.h b/drivers/gpu/drm/i915/intel_memory_region.h index 3d8378c1b447..2214f251bec3 100644 --- a/drivers/gpu/drm/i915/intel_memory_region.h +++ b/drivers/gpu/drm/i915/intel_memory_region.h @@ -127,6 +127,9 @@ int intel_memory_region_reserve(struct intel_memory_region *mem, void intel_memory_region_debug(struct intel_memory_region *mr, struct drm_printer *printer); +void intel_memory_region_avail(struct intel_memory_region *mr, + u64 *avail, u64 *visible_avail);
struct intel_memory_region * i915_gem_ttm_system_setup(struct drm_i915_private *i915, u16 type, u16 instance); diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h index 9df419a45244..e30f31a440b3 100644 --- a/include/uapi/drm/i915_drm.h +++ b/include/uapi/drm/i915_drm.h @@ -3228,7 +3228,15 @@ struct drm_i915_memory_region_info { */ __u64 probed_size; - /** @unallocated_size: Estimate of memory remaining (-1 = unknown) */ + /** + * @unallocated_size: Estimate of memory remaining (-1 = unknown) + * + * Requires CAP_PERFMON or CAP_SYS_ADMIN to get reliable accounting. + * Without this (or if this is an older kernel) the value here will + * always equal the @probed_size. Note this is only currently tracked + * for I915_MEMORY_CLASS_DEVICE regions (for other types the value here + * will always equal the @probed_size). + */ __u64 unallocated_size; union { @@ -3262,6 +3270,27 @@ struct drm_i915_memory_region_info { * @probed_size. */ __u64 probed_cpu_visible_size;
+ /** + * @unallocated_cpu_visible_size: Estimate of CPU + * visible memory remaining (-1 = unknown). + * + * Note this is only tracked for + * I915_MEMORY_CLASS_DEVICE regions (for other types the + * value here will always equal the + * @probed_cpu_visible_size). + * + * Requires CAP_PERFMON or CAP_SYS_ADMIN to get reliable + * accounting. Without this the value here will always + * equal the @probed_cpu_visible_size. Note this is only + * currently tracked for I915_MEMORY_CLASS_DEVICE + * regions (for other types the value here will also + * always equal the @probed_cpu_visible_size). + * + * If this is an older kernel the value here will be + * zero, see also @probed_cpu_visible_size. + */ + __u64 unallocated_cpu_visible_size; }; }; };