drm/i915: Restore control over ppgtt for context creation ABI

Having hid the partially exposed new ABI from the PR, put it back again
for completion of context recovery. A significant part of context
recovery is the ability to reuse as much of the old context as is
feasible (to avoid expensive reconstruction). The biggest chunk kept
hidden at the moment is fine-control over the ctx->ppgtt (the GPU page
tables and associated translation tables and kernel maps), so make
control over the ctx->ppgtt explicit.

This allows userspace to create and share virtual memory address spaces
(within the limits of a single fd) between contexts they own, along with
the ability to query the contexts for the vm state.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190521211134.16117-1-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 2c7a4318d13cfeb3ae4c085df030c659a032eea5..5061cb32856b1a7af0e64cd714a5f5e747a65ca3 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -3164,6 +3164,8 @@ static const struct drm_ioctl_desc i915_ioctls[] = {
        DRM_IOCTL_DEF_DRV(I915_PERF_ADD_CONFIG, i915_perf_add_config_ioctl, DRM_UNLOCKED|DRM_RENDER_ALLOW),
        DRM_IOCTL_DEF_DRV(I915_PERF_REMOVE_CONFIG, i915_perf_remove_config_ioctl, DRM_UNLOCKED|DRM_RENDER_ALLOW),
        DRM_IOCTL_DEF_DRV(I915_QUERY, i915_query_ioctl, DRM_UNLOCKED|DRM_RENDER_ALLOW),
+       DRM_IOCTL_DEF_DRV(I915_GEM_VM_CREATE, i915_gem_vm_create_ioctl, DRM_RENDER_ALLOW),
+       DRM_IOCTL_DEF_DRV(I915_GEM_VM_DESTROY, i915_gem_vm_destroy_ioctl, DRM_RENDER_ALLOW),
 };
 
 static struct drm_driver driver = {

diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index 65cefc520e79ff6e98def7c7488c8d875cf0b44c..413c4529191dc453f0a8de24c253014090f89d1d 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -98,7 +98,6 @@
 #include "i915_user_extensions.h"
 
 #define I915_CONTEXT_CREATE_FLAGS_SINGLE_TIMELINE (1 << 1)
-#define I915_CONTEXT_PARAM_VM 0x9
 
 #define ALL_L3_SLICES(dev) (1 << NUM_L3_SLICES(dev)) - 1
 
@@ -966,8 +965,6 @@ static int get_ppgtt(struct drm_i915_file_private *file_priv,
        struct i915_hw_ppgtt *ppgtt;
        int ret;
 
-       return -EINVAL; /* nothing to see here; please move along */
-
        if (!ctx->ppgtt)
                return -ENODEV;
 
@@ -1066,8 +1063,6 @@ static int set_ppgtt(struct drm_i915_file_private *file_priv,
        struct i915_hw_ppgtt *ppgtt, *old;
        int err;
 
-       return -EINVAL; /* nothing to see here; please move along */
-
        if (args->size)
                return -EINVAL;
 

diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
index 3a73f5316766c4216416929f774e4c56f9f92024..d6ad4a15b2b925c7840930f9464e7f156b881176 100644 (file)
--- a/include/uapi/drm/i915_drm.h
+++ b/include/uapi/drm/i915_drm.h
@@ -355,6 +355,8 @@ typedef struct _drm_i915_sarea {
 #define DRM_I915_PERF_ADD_CONFIG       0x37
 #define DRM_I915_PERF_REMOVE_CONFIG    0x38
 #define DRM_I915_QUERY                 0x39
+#define DRM_I915_GEM_VM_CREATE         0x3a
+#define DRM_I915_GEM_VM_DESTROY                0x3b
 /* Must be kept compact -- no holes */
 
 #define DRM_IOCTL_I915_INIT            DRM_IOW( DRM_COMMAND_BASE + DRM_I915_INIT, drm_i915_init_t)
@@ -415,6 +417,8 @@ typedef struct _drm_i915_sarea {
 #define DRM_IOCTL_I915_PERF_ADD_CONFIG DRM_IOW(DRM_COMMAND_BASE + DRM_I915_PERF_ADD_CONFIG, struct drm_i915_perf_oa_config)
 #define DRM_IOCTL_I915_PERF_REMOVE_CONFIG      DRM_IOW(DRM_COMMAND_BASE + DRM_I915_PERF_REMOVE_CONFIG, __u64)
 #define DRM_IOCTL_I915_QUERY                   DRM_IOWR(DRM_COMMAND_BASE + DRM_I915_QUERY, struct drm_i915_query)
+#define DRM_IOCTL_I915_GEM_VM_CREATE   DRM_IOWR(DRM_COMMAND_BASE + DRM_I915_GEM_VM_CREATE, struct drm_i915_gem_vm_control)
+#define DRM_IOCTL_I915_GEM_VM_DESTROY  DRM_IOW (DRM_COMMAND_BASE + DRM_I915_GEM_VM_DESTROY, struct drm_i915_gem_vm_control)
 
 /* Allow drivers to submit batchbuffers directly to hardware, relying
  * on the security mechanisms provided by hardware.
@@ -1507,6 +1511,17 @@ struct drm_i915_gem_context_param {
  * On creation, all new contexts are marked as recoverable.
  */
 #define I915_CONTEXT_PARAM_RECOVERABLE 0x8
+
+       /*
+        * The id of the associated virtual memory address space (ppGTT) of
+        * this context. Can be retrieved and passed to another context
+        * (on the same fd) for both to use the same ppGTT and so share
+        * address layouts, and avoid reloading the page tables on context
+        * switches between themselves.
+        *
+        * See DRM_I915_GEM_VM_CREATE and DRM_I915_GEM_VM_DESTROY.
+        */
+#define I915_CONTEXT_PARAM_VM          0x9
 /* Must be kept compact -- no holes and well documented */
 
        __u64 value;