[PATCH v1 02/12] drm/i915: vgpu shared memory setup for pv support
Xiaolin Zhang
xiaolin.zhang at intel.com
Fri Sep 4 16:21:35 UTC 2020
To support vgpu pv features, a common shared memory is setup used for
communication and data exchange between guest and host GVTg to reduce
data access overhead and trap cost.
guest i915 will allocate this common memory (1 page size) and then pass
it's physical address to host GVTg through PVINFO register so that host
GVTg can access this shared guest page meory without trap cost with
hyperviser's facility.
guest i915 will send VGT_G2V_SHARED_PAGE_SETUP notification to host GVTg
once shared memory setup succcessfully finished.
the layout of the shared_page also defined as well, the first part is the
PV vervsion information used for compabilty support.
Signed-off-by: Xiaolin Zhang <xiaolin.zhang at intel.com>
---
drivers/gpu/drm/i915/i915_drv.c | 2 +
drivers/gpu/drm/i915/i915_drv.h | 4 +-
drivers/gpu/drm/i915/i915_pvinfo.h | 5 +-
drivers/gpu/drm/i915/i915_vgpu.c | 94 ++++++++++++++++++++++++++++++++++++++
drivers/gpu/drm/i915/i915_vgpu.h | 14 ++++++
5 files changed, 117 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 00292a8..5fbb4ab 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1071,6 +1071,8 @@ static void i915_driver_release(struct drm_device *dev)
disable_rpm_wakeref_asserts(rpm);
+ intel_vgpu_destroy(dev_priv);
+
i915_gem_driver_release(dev_priv);
intel_memory_regions_driver_release(dev_priv);
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 16d1b51..3cde2c5f 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -809,7 +809,9 @@ struct i915_virtual_gpu {
bool active;
u32 caps;
u32 pv_caps;
-};
+
+ struct i915_virtual_gpu_pv *pv;
+} __packed;
struct intel_cdclk_config {
unsigned int cdclk, vco, ref, bypass;
diff --git a/drivers/gpu/drm/i915/i915_pvinfo.h b/drivers/gpu/drm/i915/i915_pvinfo.h
index 8b0dc25..1d44876 100644
--- a/drivers/gpu/drm/i915/i915_pvinfo.h
+++ b/drivers/gpu/drm/i915/i915_pvinfo.h
@@ -48,6 +48,7 @@ enum vgt_g2v_type {
VGT_G2V_PPGTT_L4_PAGE_TABLE_DESTROY,
VGT_G2V_EXECLIST_CONTEXT_CREATE,
VGT_G2V_EXECLIST_CONTEXT_DESTROY,
+ VGT_G2V_SHARED_PAGE_REGISTER,
VGT_G2V_MAX,
};
@@ -112,7 +113,9 @@ struct vgt_if {
u32 pv_caps;
- u32 rsv7[0x200 - 25]; /* pad to one page */
+ u64 shared_page_gpa;
+
+ u32 rsv7[0x200 - 27]; /* pad to one page */
} __packed;
#define vgtif_offset(x) (offsetof(struct vgt_if, x))
diff --git a/drivers/gpu/drm/i915/i915_vgpu.c b/drivers/gpu/drm/i915/i915_vgpu.c
index 10960125..8b2b451 100644
--- a/drivers/gpu/drm/i915/i915_vgpu.c
+++ b/drivers/gpu/drm/i915/i915_vgpu.c
@@ -110,6 +110,17 @@ void intel_vgpu_detect(struct drm_i915_private *dev_priv)
pci_iounmap(pdev, shared_area);
}
+void intel_vgpu_destroy(struct drm_i915_private *i915)
+{
+ struct i915_virtual_gpu_pv *pv = i915->vgpu.pv;
+
+ if (!intel_vgpu_active(i915) || !pv)
+ return;
+
+ __free_page(virt_to_page(pv->shared_page));
+ kfree(pv);
+}
+
void intel_vgpu_register(struct drm_i915_private *i915)
{
/*
@@ -360,6 +371,83 @@ int intel_vgt_balloon(struct i915_ggtt *ggtt)
*/
/*
+ * shared_page setup for VGPU PV features
+ */
+static int intel_vgpu_setup_shared_page(struct drm_i915_private *i915,
+ void __iomem *shared_area)
+{
+ void __iomem *addr;
+ struct i915_virtual_gpu_pv *pv;
+ struct gvt_shared_page *base;
+ u64 gpa;
+ u16 ver_maj, ver_min;
+ int ret = 0;
+
+ /* We allocate 1 page shared between guest and GVT for data exchange.
+ * _______________________________
+ * |version |
+ * |_______________________________PAGE/8
+ * | |
+ * |_______________________________PAGE/4
+ * | |
+ * | |
+ * | |
+ * |_______________________________PAGE/2
+ * | |
+ * | |
+ * | |
+ * | |
+ * | |
+ * | |
+ * | |
+ * |_______________________________|
+ *
+ * 0 offset: PV version area
+ */
+
+ base = (struct gvt_shared_page *)get_zeroed_page(GFP_KERNEL);
+ if (!base) {
+ dev_info(i915->drm.dev, "out of memory for shared memory\n");
+ return -ENOMEM;
+ }
+
+ /* pass guest memory pa address to GVT and then read back to verify */
+ gpa = __pa(base);
+ addr = shared_area + vgtif_offset(shared_page_gpa);
+ writeq(gpa, addr);
+ if (gpa != readq(addr)) {
+ dev_info(i915->drm.dev, "passed shared_page_gpa failed\n");
+ ret = -EIO;
+ goto err;
+ }
+
+ addr = shared_area + vgtif_offset(g2v_notify);
+ writel(VGT_G2V_SHARED_PAGE_REGISTER, addr);
+
+ ver_maj = base->ver_major;
+ ver_min = base->ver_minor;
+ if (ver_maj != PV_MAJOR || ver_min != PV_MINOR) {
+ dev_info(i915->drm.dev, "VGPU PV version incompatible\n");
+ ret = -EIO;
+ goto err;
+ }
+
+ pv = kzalloc(sizeof(struct i915_virtual_gpu_pv), GFP_KERNEL);
+ if (!pv) {
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ DRM_INFO("vgpu PV ver major %d and minor %d\n", ver_maj, ver_min);
+ i915->vgpu.pv = pv;
+ pv->shared_page = base;
+ return ret;
+err:
+ __free_page(virt_to_page(base));
+ return ret;
+}
+
+/*
* Config vgpu PV ops for different PV capabilities
*/
void intel_vgpu_config_pv_caps(struct drm_i915_private *i915,
@@ -395,5 +483,11 @@ bool intel_vgpu_detect_pv_caps(struct drm_i915_private *i915,
if (!pvcaps)
return false;
+ if (intel_vgpu_setup_shared_page(i915, shared_area)) {
+ i915->vgpu.pv_caps = 0;
+ writel(0, shared_area + vgtif_offset(pv_caps));
+ return false;
+ }
+
return true;
}
diff --git a/drivers/gpu/drm/i915/i915_vgpu.h b/drivers/gpu/drm/i915/i915_vgpu.h
index 1b10175..aeef20f 100644
--- a/drivers/gpu/drm/i915/i915_vgpu.h
+++ b/drivers/gpu/drm/i915/i915_vgpu.h
@@ -29,12 +29,26 @@
struct drm_i915_private;
struct i915_ggtt;
+#define PV_MAJOR 0
+#define PV_MINOR 1
+
/* define different PV capabilities */
enum pv_caps {
PV_NONE = 0,
};
+/* A common shared page(4KB) between GVTg and vgpu allocated by guest */
+struct gvt_shared_page {
+ u16 ver_major;
+ u16 ver_minor;
+};
+
+struct i915_virtual_gpu_pv {
+ struct gvt_shared_page *shared_page;
+};
+
void intel_vgpu_detect(struct drm_i915_private *i915);
+void intel_vgpu_destroy(struct drm_i915_private *i915);
bool intel_vgpu_active(struct drm_i915_private *i915);
void intel_vgpu_register(struct drm_i915_private *i915);
bool intel_vgpu_has_full_ppgtt(struct drm_i915_private *i915);
--
2.7.4
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