drm/vmwgfx: Detect old user-space drivers and set up legacy emulation v2

GB aware mesa userspace drivers are detected by the fact that they are
calling the vmw getparam ioctl querying DRM_VMW_PARAM_HW_CAPS to detect
whether the device is Guest-backed object capable. For other drivers,
lie about hardware version and send the 3D capabilities in a format they
expect.

v2:
Use DRM_VMW_PARAM_MAX_MOB_MEMORY to detect gb awareness,
Make sure we don't ovwerwrite bounce buffer or write past user-space buffer
indicated size.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Jakob Bornecrantz <jakob@vmware.com>

2 files changed, 101 insertions, 16 deletions

diff --git a/drivers/gpu/drm/vmwgfx/svga3d_reg.h b/drivers/gpu/drm/vmwgfx/svga3d_reg.h
index d95335cb90bd..b645647b7776 100644
--- a/drivers/gpu/drm/vmwgfx/svga3d_reg.h
+++ b/drivers/gpu/drm/vmwgfx/svga3d_reg.h
@@ -2583,4 +2583,28 @@ typedef union {
    float  f;
 } SVGA3dDevCapResult;
 
+typedef enum {
+   SVGA3DCAPS_RECORD_UNKNOWN        = 0,
+   SVGA3DCAPS_RECORD_DEVCAPS_MIN    = 0x100,
+   SVGA3DCAPS_RECORD_DEVCAPS        = 0x100,
+   SVGA3DCAPS_RECORD_DEVCAPS_MAX    = 0x1ff,
+} SVGA3dCapsRecordType;
+
+typedef
+struct SVGA3dCapsRecordHeader {
+   uint32 length;
+   SVGA3dCapsRecordType type;
+}
+SVGA3dCapsRecordHeader;
+
+typedef
+struct SVGA3dCapsRecord {
+   SVGA3dCapsRecordHeader header;
+   uint32 data[1];
+}
+SVGA3dCapsRecord;
+
+
+typedef uint32 SVGA3dCapPair[2];
+
 #endif /* _SVGA3D_REG_H_ */
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c b/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c
index 116c49736763..f9881f9e62bd 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c
@@ -29,12 +29,18 @@
 #include <drm/vmwgfx_drm.h>
 #include "vmwgfx_kms.h"
 
+struct svga_3d_compat_cap {
+        SVGA3dCapsRecordHeader header;
+        SVGA3dCapPair pairs[SVGA3D_DEVCAP_MAX];
+};
+
 int vmw_getparam_ioctl(struct drm_device *dev, void *data,
                        struct drm_file *file_priv)
 {
         struct vmw_private *dev_priv = vmw_priv(dev);
         struct drm_vmw_getparam_arg *param =
             (struct drm_vmw_getparam_arg *)data;
+        struct vmw_fpriv *vmw_fp = vmw_fpriv(file_priv);
 
         switch (param->param) {
         case DRM_VMW_PARAM_NUM_STREAMS:
@@ -60,6 +66,11 @@ int vmw_getparam_ioctl(struct drm_device *dev, void *data,
                 __le32 __iomem *fifo_mem = dev_priv->mmio_virt;
                 const struct vmw_fifo_state *fifo = &dev_priv->fifo;
 
+                if ((dev_priv->capabilities & SVGA_CAP_GBOBJECTS)) {
+                        param->value = SVGA3D_HWVERSION_WS8_B1;
+                        break;
+                }
+
                 param->value =
                         ioread32(fifo_mem +
                                  ((fifo->capabilities &
@@ -69,17 +80,26 @@ int vmw_getparam_ioctl(struct drm_device *dev, void *data,
                 break;
         }
         case DRM_VMW_PARAM_MAX_SURF_MEMORY:
-                param->value = dev_priv->memory_size;
+                if ((dev_priv->capabilities & SVGA_CAP_GBOBJECTS) &&
+                    !vmw_fp->gb_aware)
+                        param->value = dev_priv->max_mob_pages * PAGE_SIZE / 2;
+                else
+                        param->value = dev_priv->memory_size;
                 break;
         case DRM_VMW_PARAM_3D_CAPS_SIZE:
-                if (dev_priv->capabilities & SVGA_CAP_GBOBJECTS)
-                        param->value = SVGA3D_DEVCAP_MAX;
+                if ((dev_priv->capabilities & SVGA_CAP_GBOBJECTS) &&
+                    vmw_fp->gb_aware)
+                        param->value = SVGA3D_DEVCAP_MAX * sizeof(uint32_t);
+                else if (dev_priv->capabilities & SVGA_CAP_GBOBJECTS)
+                        param->value = sizeof(struct svga_3d_compat_cap) +
+                                sizeof(uint32_t);
                 else
                         param->value = (SVGA_FIFO_3D_CAPS_LAST -
-                                        SVGA_FIFO_3D_CAPS + 1);
-                param->value *= sizeof(uint32_t);
+                                        SVGA_FIFO_3D_CAPS + 1) *
+                                sizeof(uint32_t);
                 break;
         case DRM_VMW_PARAM_MAX_MOB_MEMORY:
+                vmw_fp->gb_aware = true;
                 param->value = dev_priv->max_mob_pages * PAGE_SIZE;
                 break;
         default:
@@ -91,6 +111,38 @@ int vmw_getparam_ioctl(struct drm_device *dev, void *data,
         return 0;
 }
 
+static int vmw_fill_compat_cap(struct vmw_private *dev_priv, void *bounce,
+                               size_t size)
+{
+        struct svga_3d_compat_cap *compat_cap =
+                (struct svga_3d_compat_cap *) bounce;
+        unsigned int i;
+        size_t pair_offset = offsetof(struct svga_3d_compat_cap, pairs);
+        unsigned int max_size;
+
+        if (size < pair_offset)
+                return -EINVAL;
+
+        max_size = (size - pair_offset) / sizeof(SVGA3dCapPair);
+
+        if (max_size > SVGA3D_DEVCAP_MAX)
+                max_size = SVGA3D_DEVCAP_MAX;
+
+        compat_cap->header.length =
+                (pair_offset + max_size * sizeof(SVGA3dCapPair)) / sizeof(u32);
+        compat_cap->header.type = SVGA3DCAPS_RECORD_DEVCAPS;
+
+        mutex_lock(&dev_priv->hw_mutex);
+        for (i = 0; i < max_size; ++i) {
+                vmw_write(dev_priv, SVGA_REG_DEV_CAP, i);
+                compat_cap->pairs[i][0] = i;
+                compat_cap->pairs[i][1] = vmw_read(dev_priv, SVGA_REG_DEV_CAP);
+        }
+        mutex_unlock(&dev_priv->hw_mutex);
+
+        return 0;
+}
+
 
 int vmw_get_cap_3d_ioctl(struct drm_device *dev, void *data,
                          struct drm_file *file_priv)
@@ -104,41 +156,49 @@ int vmw_get_cap_3d_ioctl(struct drm_device *dev, void *data,
         void *bounce;
         int ret;
         bool gb_objects = !!(dev_priv->capabilities & SVGA_CAP_GBOBJECTS);
+        struct vmw_fpriv *vmw_fp = vmw_fpriv(file_priv);
 
         if (unlikely(arg->pad64 != 0)) {
                 DRM_ERROR("Illegal GET_3D_CAP argument.\n");
                 return -EINVAL;
         }
 
-        if (gb_objects)
-                size = SVGA3D_DEVCAP_MAX;
+        if (gb_objects && vmw_fp->gb_aware)
+                size = SVGA3D_DEVCAP_MAX * sizeof(uint32_t);
+        else if (gb_objects)
+                size = sizeof(struct svga_3d_compat_cap) + sizeof(uint32_t);
         else
-                size = (SVGA_FIFO_3D_CAPS_LAST - SVGA_FIFO_3D_CAPS + 1);
-
-        size *= sizeof(uint32_t);
+                size = (SVGA_FIFO_3D_CAPS_LAST - SVGA_FIFO_3D_CAPS + 1) *
+                        sizeof(uint32_t);
 
         if (arg->max_size < size)
                 size = arg->max_size;
 
-        bounce = vmalloc(size);
+        bounce = vzalloc(size);
         if (unlikely(bounce == NULL)) {
                 DRM_ERROR("Failed to allocate bounce buffer for 3D caps.\n");
                 return -ENOMEM;
         }
 
-        if (gb_objects) {
-                int i;
+        if (gb_objects && vmw_fp->gb_aware) {
+                int i, num;
                 uint32_t *bounce32 = (uint32_t *) bounce;
 
+                num = size / sizeof(uint32_t);
+                if (num > SVGA3D_DEVCAP_MAX)
+                        num = SVGA3D_DEVCAP_MAX;
+
                 mutex_lock(&dev_priv->hw_mutex);
-                for (i = 0; i < SVGA3D_DEVCAP_MAX; ++i) {
+                for (i = 0; i < num; ++i) {
                         vmw_write(dev_priv, SVGA_REG_DEV_CAP, i);
                         *bounce32++ = vmw_read(dev_priv, SVGA_REG_DEV_CAP);
                 }
                 mutex_unlock(&dev_priv->hw_mutex);
-
+        } else if (gb_objects) {
+                ret = vmw_fill_compat_cap(dev_priv, bounce, size);
+                if (unlikely(ret != 0))
+                        goto out_err;
         } else {
-
                 fifo_mem = dev_priv->mmio_virt;
                 memcpy_fromio(bounce, &fifo_mem[SVGA_FIFO_3D_CAPS], size);
         }
@@ -146,6 +206,7 @@ int vmw_get_cap_3d_ioctl(struct drm_device *dev, void *data,
         ret = copy_to_user(buffer, bounce, size);
         if (ret)
                 ret = -EFAULT;
+out_err:
         vfree(bounce);
 
         if (unlikely(ret != 0))