[PATCH v10 4/9] drm/i915: vgpu ppgtt update pv optimization

Xiaolin Zhang
2019-09-17T05:48:15Z

This patch extends vgpu ppgtt g2v notification to notify host
GVT-g of ppgtt update from guest including alloc_4lvl, clear_4lv4
and insert_4lvl.

These updates use the shared memory page to pass struct pv_ppgtt_update
from guest to GVT which is used for pv optimiation implemeation within
host GVT side.

This patch also add one new pv_caps level to control ppgtt update.

Use PV_PPGTT_UPDATE to control this level of pv optimization.

v0: RFC.
v1: rebased.
v2: added pv callbacks for vm.{allocate_va_range, insert_entries,
clear_range} within ppgtt.
v3: rebased, disable huge page ppgtt support when using PVMMIO ppgtt
update due to complex and performance impact.
v4: moved alloc/insert/clear_4lvl pv callbacks into i915_vgpu_pv.c and
added a single intel_vgpu_config_pv_caps() for vgpu pv callbacks setup.
v5: rebase.
v6: rebase.
v7: rebase.

Signed-off-by: Xiaolin Zhang <xiaolin.zhang@intel.com>
---
drivers/gpu/drm/i915/i915_gem.c | 3 +-
drivers/gpu/drm/i915/i915_gem_gtt.c | 10 +++--
drivers/gpu/drm/i915/i915_gem_gtt.h | 8 ++++
drivers/gpu/drm/i915/i915_vgpu.c | 79 +++++++++++++++++++++++++++++++++++++
drivers/gpu/drm/i915/i915_vgpu.h | 25 ++++++++++++
5 files changed, 120 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 2da9544..1ade8e0 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1309,7 +1309,8 @@ int i915_gem_init(struct drm_i915_private *dev_priv)
int ret;

/* We need to fallback to 4K pages if host doesn't support huge gtt. */
- if (intel_vgpu_active(dev_priv) && !intel_vgpu_has_huge_gtt(dev_priv))
+ if ((intel_vgpu_active(dev_priv) && !intel_vgpu_has_huge_gtt(dev_priv))
+ || intel_vgpu_enabled_pv_caps(dev_priv, PV_PPGTT_UPDATE))
mkwrite_device_info(dev_priv)->page_sizes =
I915_GTT_PAGE_SIZE_4K;

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index e62e9d1..00b187a 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -1015,7 +1015,7 @@ static u64 __gen8_ppgtt_clear(struct i915_address_space * const vm,
return start;
}

-static void gen8_ppgtt_clear(struct i915_address_space *vm,
+void gen8_ppgtt_clear(struct i915_address_space *vm,
u64 start, u64 length)
{
GEM_BUG_ON(!IS_ALIGNED(start, BIT_ULL(GEN8_PTE_SHIFT)));
@@ -1126,7 +1126,7 @@ static int __gen8_ppgtt_alloc(struct i915_address_space * const vm,
return ret;
}

-static int gen8_ppgtt_alloc(struct i915_address_space *vm,
+int gen8_ppgtt_alloc(struct i915_address_space *vm,
u64 start, u64 length)
{
u64 from;
@@ -1326,7 +1326,7 @@ static void gen8_ppgtt_insert_huge(struct i915_vma *vma,
} while (iter->sg);
}

-static void gen8_ppgtt_insert(struct i915_address_space *vm,
+void gen8_ppgtt_insert(struct i915_address_space *vm,
struct i915_vma *vma,
enum i915_cache_level cache_level,
u32 flags)
@@ -1517,8 +1517,10 @@ static struct i915_ppgtt *gen8_ppgtt_create(struct drm_i915_private *i915)
ppgtt->vm.allocate_va_range = gen8_ppgtt_alloc;
ppgtt->vm.clear_range = gen8_ppgtt_clear;

- if (intel_vgpu_active(i915))
+ if (intel_vgpu_active(i915)) {
+ intel_vgpu_config_pv_caps(i915, PV_PPGTT_UPDATE, ppgtt);
gen8_ppgtt_notify_vgt(ppgtt, true);
+ }

ppgtt->vm.cleanup = gen8_ppgtt_cleanup;

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.h b/drivers/gpu/drm/i915/i915_gem_gtt.h
index 8fd2234..f5536bf 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.h
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.h
@@ -588,6 +588,14 @@ static inline void i915_vm_put(struct i915_address_space *vm)
void gen6_ppgtt_unpin(struct i915_ppgtt *base);
void gen6_ppgtt_unpin_all(struct i915_ppgtt *base);

+void gen8_ppgtt_clear(struct i915_address_space *vm,
+ u64 start, u64 length);
+void gen8_ppgtt_insert(struct i915_address_space *vm,
+ struct i915_vma *vma,
+ enum i915_cache_level cache_level, u32 flags);
+int gen8_ppgtt_alloc(struct i915_address_space *vm,
+ u64 start, u64 length);
+
void i915_gem_suspend_gtt_mappings(struct drm_i915_private *dev_priv);
void i915_gem_restore_gtt_mappings(struct drm_i915_private *dev_priv);

diff --git a/drivers/gpu/drm/i915/i915_vgpu.c b/drivers/gpu/drm/i915/i915_vgpu.c
index 6e29a52..e458892 100644
--- a/drivers/gpu/drm/i915/i915_vgpu.c
+++ b/drivers/gpu/drm/i915/i915_vgpu.c
@@ -96,6 +96,9 @@ void i915_detect_vgpu(struct drm_i915_private *dev_priv)
dev_priv->vgpu.active = true;
mutex_init(&dev_priv->vgpu.lock);

+ /* guest driver PV capability */
+ dev_priv->vgpu.pv_caps = PV_PPGTT_UPDATE;
+
if (!intel_vgpu_check_pv_caps(dev_priv, shared_area)) {
DRM_INFO("Virtual GPU for Intel GVT-g detected.\n");
goto out;
@@ -322,6 +325,82 @@ int intel_vgt_balloon(struct i915_ggtt *ggtt)
* i915 vgpu PV support for Linux
*/

+static int vgpu_ppgtt_pv_update(struct drm_i915_private *dev_priv,
+ u32 action, u64 pdp, u64 start, u64 length, u32 cache_level)
+{
+ u32 data[8];
+
+ data[0] = action;
+ data[1] = lower_32_bits(pdp);
+ data[2] = upper_32_bits(pdp);
+ data[3] = lower_32_bits(start);
+ data[4] = upper_32_bits(start);
+ data[5] = lower_32_bits(length);
+ data[6] = upper_32_bits(length);
+ data[7] = cache_level;
+
+ return intel_vgpu_pv_send(dev_priv, data, ARRAY_SIZE(data));
+}
+
+static void gen8_ppgtt_clear_4lvl_pv(struct i915_address_space *vm,
+ u64 start, u64 length)
+{
+ struct i915_ppgtt *ppgtt = i915_vm_to_ppgtt(vm);
+ struct drm_i915_private *dev_priv = vm->i915;
+
+ gen8_ppgtt_clear(vm, start, length);
+ vgpu_ppgtt_pv_update(dev_priv, PV_ACTION_PPGTT_L4_CLEAR,
+ px_dma(ppgtt->pd), start, length, 0);
+}
+
+static void gen8_ppgtt_insert_4lvl_pv(struct i915_address_space *vm,
+ struct i915_vma *vma,
+ enum i915_cache_level cache_level, u32 flags)
+{
+ struct i915_ppgtt *ppgtt = i915_vm_to_ppgtt(vm);
+ struct drm_i915_private *dev_priv = vm->i915;
+ u64 start = vma->node.start;
+ u64 length = vma->node.size;
+
+ gen8_ppgtt_insert(vm, vma, cache_level, flags);
+ vgpu_ppgtt_pv_update(dev_priv, PV_ACTION_PPGTT_L4_INSERT,
+ px_dma(ppgtt->pd), start, length, cache_level);
+}
+
+static int gen8_ppgtt_alloc_4lvl_pv(struct i915_address_space *vm,
+ u64 start, u64 length)
+{
+ struct i915_ppgtt *ppgtt = i915_vm_to_ppgtt(vm);
+ struct drm_i915_private *dev_priv = vm->i915;
+ int ret;
+
+ ret = gen8_ppgtt_alloc(vm, start, length);
+ if (ret)
+ return ret;
+
+ return vgpu_ppgtt_pv_update(dev_priv, PV_ACTION_PPGTT_L4_ALLOC,
+ px_dma(ppgtt->pd), start, length, 0);
+}
+
+/*
+ * config guest driver PV ops for different PV features
+ */
+void intel_vgpu_config_pv_caps(struct drm_i915_private *dev_priv,
+ enum pv_caps cap, void *data)
+{
+ struct i915_ppgtt *ppgtt;
+
+ if (!intel_vgpu_enabled_pv_caps(dev_priv, cap))
+ return;
+
+ if (cap == PV_PPGTT_UPDATE) {
+ ppgtt = (struct i915_ppgtt *)data;
+ ppgtt->vm.allocate_va_range = gen8_ppgtt_alloc_4lvl_pv;
+ ppgtt->vm.insert_entries = gen8_ppgtt_insert_4lvl_pv;
+ ppgtt->vm.clear_range = gen8_ppgtt_clear_4lvl_pv;
+ }
+}
+
/**
* wait_for_desc_update - Wait for the command buffer descriptor update.
* @desc: buffer descriptor
diff --git a/drivers/gpu/drm/i915/i915_vgpu.h b/drivers/gpu/drm/i915/i915_vgpu.h
index c494beb..b0fee5b 100644
--- a/drivers/gpu/drm/i915/i915_vgpu.h
+++ b/drivers/gpu/drm/i915/i915_vgpu.h
@@ -33,6 +33,21 @@
#define PV_CMD_OFF (PAGE_SIZE/2)

/*
+ * define different capabilities of PV optimization
+ */
+enum pv_caps {
+ PV_PPGTT_UPDATE = 0x1,
+};
+
+/* PV actions */
+enum intel_vgpu_pv_action {
+ PV_ACTION_DEFAULT = 0x0,
+ PV_ACTION_PPGTT_L4_ALLOC,
+ PV_ACTION_PPGTT_L4_CLEAR,
+ PV_ACTION_PPGTT_L4_INSERT,
+};
+
+/*
* A shared page(4KB) between gvt and VM, could be allocated by guest driver
* or a fixed location in PCI bar 0 region
*/
@@ -120,6 +135,14 @@ struct i915_virtual_gpu_pv {
return dev_priv->vgpu.caps & VGT_CAPS_PV;
}

+static inline bool
+intel_vgpu_enabled_pv_caps(struct drm_i915_private *dev_priv,
+ enum pv_caps cap)
+{
+ return (dev_priv->vgpu.active) && intel_vgpu_has_pv_caps(dev_priv)
+ && (dev_priv->vgpu.pv_caps & cap);
+}
+
static inline void
intel_vgpu_pv_notify(struct drm_i915_private *dev_priv)
{
@@ -139,4 +162,6 @@ struct i915_virtual_gpu_pv {
/* i915 vgpu pv related functions */
bool intel_vgpu_check_pv_caps(struct drm_i915_private *dev_priv,
void __iomem *shared_area);
+void intel_vgpu_config_pv_caps(struct drm_i915_private *dev_priv,
+ enum pv_caps cap, void *data);
#endif /* _I915_VGPU_H_ */