[PATCH 1/3] drm/vmwgfx: Drop mksstat_init_record fn as currently unused

[PATCH 1/3] drm/vmwgfx: Drop mksstat_init_record fn as currently unused

[Zack Rusin]

From: Martin Krastev <krastevm@vmware.com>

This internal helper handles a type of mksstat event counter
which is currently unused. Remove the routine to avoid compile
warnings.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Martin Krastev <krastevm@vmware.com>
Reviewed-by: Maaz Mombasawala <mombasawalam@vmware.com>
Reviewed-by: Zack Rusin <zackr@vmware.com>
Signed-off-by: Zack Rusin <zackr@vmware.com>
---
 drivers/gpu/drm/vmwgfx/vmwgfx_msg.c | 26 --------------------------
 1 file changed, 26 deletions(-)

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c b/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c
index e76976a95a1e..ca1a3fe44fa5 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c
@@ -702,32 +702,6 @@ static inline void hypervisor_ppn_remove(PPN64 pfn)
 /* Header to the text description of mksGuestStat instance descriptor */
 #define MKSSTAT_KERNEL_DESCRIPTION "vmwgfx"
 
-/**
- * mksstat_init_record: Initializes an MKSGuestStatCounter-based record
- * for the respective mksGuestStat index.
- *
- * @stat_idx: Index of the MKSGuestStatCounter-based mksGuestStat record.
- * @pstat: Pointer to array of MKSGuestStatCounterTime.
- * @pinfo: Pointer to array of MKSGuestStatInfoEntry.
- * @pstrs: Pointer to current end of the name/description sequence.
- * Return: Pointer to the new end of the names/description sequence.
- */
-
-static inline char *mksstat_init_record(mksstat_kern_stats_t stat_idx,
-	MKSGuestStatCounterTime *pstat, MKSGuestStatInfoEntry *pinfo, char *pstrs)
-{
-	char *const pstrd = pstrs + strlen(mksstat_kern_name_desc[stat_idx][0]) + 1;
-	strcpy(pstrs, mksstat_kern_name_desc[stat_idx][0]);
-	strcpy(pstrd, mksstat_kern_name_desc[stat_idx][1]);
-
-	pinfo[stat_idx].name.s = pstrs;
-	pinfo[stat_idx].description.s = pstrd;
-	pinfo[stat_idx].flags = MKS_GUEST_STAT_FLAG_NONE;
-	pinfo[stat_idx].stat.counter = (MKSGuestStatCounter *)&pstat[stat_idx];
-
-	return pstrd + strlen(mksstat_kern_name_desc[stat_idx][1]) + 1;
-}
-
 /**
  * mksstat_init_record_time: Initializes an MKSGuestStatCounterTime-based record
  * for the respective mksGuestStat index.
-- 
2.38.1

[PATCH 2/3] drm/vmwgfx: Print errors when running on broken/unsupported configs

[Zack Rusin]

From: Zack Rusin <zackr@vmware.com>

virtualbox implemented an incomplete version of the svga device which
they decided to drop soon after the initial release. The device was
always broken in various ways and never supported by vmwgfx.

vmwgfx should refuse to load on those configurations but currently
drm has no way of reloading fbdev when the specific pci driver refuses
to load, which would leave users without a usable fb. Instead of
refusing to load print an error and disable a bunch of functionality
that virtualbox never implemented to at least get fb to work on their
setup.

Signed-off-by: Zack Rusin <zackr@vmware.com>
---
 drivers/gpu/drm/vmwgfx/vmwgfx_drv.c | 29 +++++++++++++++++++++++++++++
 drivers/gpu/drm/vmwgfx/vmwgfx_drv.h |  2 ++
 drivers/gpu/drm/vmwgfx/vmwgfx_msg.c |  9 +++++++++
 3 files changed, 40 insertions(+)

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
index 2588615a2a38..8b24ecf60e3e 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
@@ -45,6 +45,9 @@
 #include <drm/ttm/ttm_placement.h>
 #include <generated/utsrelease.h>
 
+#ifdef CONFIG_X86
+#include <asm/hypervisor.h>
+#endif
 #include <linux/cc_platform.h>
 #include <linux/dma-mapping.h>
 #include <linux/module.h>
@@ -897,6 +900,16 @@ static int vmw_driver_load(struct vmw_private *dev_priv, u32 pci_id)
 				 cap2_names, ARRAY_SIZE(cap2_names));
 	}
 
+	if (!vmwgfx_supported(dev_priv)) {
+		vmw_disable_backdoor();
+		drm_err_once(&dev_priv->drm,
+			     "vmwgfx seems to be running on an unsupported hypervisor.");
+		drm_err_once(&dev_priv->drm,
+			     "This configuration is likely broken.");
+		drm_err_once(&dev_priv->drm,
+			     "Please switch to a supported graphics device to avoid problems.");
+	}
+
 	ret = vmw_dma_select_mode(dev_priv);
 	if (unlikely(ret != 0)) {
 		drm_info(&dev_priv->drm,
@@ -1320,6 +1333,22 @@ static void vmw_master_drop(struct drm_device *dev,
 	vmw_kms_legacy_hotspot_clear(dev_priv);
 }
 
+bool vmwgfx_supported(struct vmw_private *vmw)
+{
+#if defined(CONFIG_X86)
+	return hypervisor_is_type(X86_HYPER_VMWARE);
+#elif defined(CONFIG_ARM64)
+	/*
+	 * On aarch64 only svga3 is supported
+	 */
+	return vmw->pci_id == VMWGFX_PCI_ID_SVGA3;
+#else
+	drm_warn_once(&vmw->drm,
+		      "vmwgfx is running on an unknown architecture.");
+	return false;
+#endif
+}
+
 /**
  * __vmw_svga_enable - Enable SVGA mode, FIFO and use of VRAM.
  *
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
index fb8f0c0642c0..3810a9984a7f 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
@@ -773,6 +773,7 @@ static inline u32 vmw_max_num_uavs(struct vmw_private *dev_priv)
 
 extern void vmw_svga_enable(struct vmw_private *dev_priv);
 extern void vmw_svga_disable(struct vmw_private *dev_priv);
+bool vmwgfx_supported(struct vmw_private *vmw);
 
 
 /**
@@ -1358,6 +1359,7 @@ int vmw_bo_cpu_blit(struct ttm_buffer_object *dst,
 		    struct vmw_diff_cpy *diff);
 
 /* Host messaging -vmwgfx_msg.c: */
+void vmw_disable_backdoor(void);
 int vmw_host_get_guestinfo(const char *guest_info_param,
 			   char *buffer, size_t *length);
 __printf(1, 2) int vmw_host_printf(const char *fmt, ...);
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c b/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c
index ca1a3fe44fa5..2651fe0ef518 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c
@@ -1179,3 +1179,12 @@ int vmw_mksstat_remove_ioctl(struct drm_device *dev, void *data,
 
 	return -EAGAIN;
 }
+
+/**
+ * vmw_disable_backdoor: Disables all backdoor communication
+ * with the hypervisor.
+ */
+void vmw_disable_backdoor(void)
+{
+	vmw_msg_enabled = 0;
+}
-- 
2.38.1

[PATCH 3/3] drm/vmwgfx: Fix Legacy Display Unit atomic drm support

[Zack Rusin]

From: Martin Krastev <krastevm@vmware.com>

Legacy Display Unit (LDU) fb dirty support used a custom fb dirty callback. Latter
handled only the DIRTYFB IOCTL presentation path but not the ADDFB2/PAGE_FLIP/RMFB
IOCTL path, common for Wayland compositors.

Get rid of the custom callback in favor of drm_atomic_helper_dirtyfb and unify the
handling of the presentation paths inside of vmw_ldu_primary_plane_atomic_update.
This also homogenizes the fb dirty callbacks across all DUs: LDU, SOU and STDU.

Signed-off-by: Martin Krastev <krastevm@vmware.com>
Reviewed-by: Maaz Mombasawala <mombasawalam@vmware.com>
Fixes: 2f5544ff0300 ("drm/vmwgfx: Use atomic helper function for dirty fb IOCTL")
Cc: <stable@vger.kernel.org> # v5.0+
Signed-off-by: Zack Rusin <zackr@vmware.com>
---
 drivers/gpu/drm/vmwgfx/vmwgfx_kms.c | 62 +----------------------------
 drivers/gpu/drm/vmwgfx/vmwgfx_kms.h |  5 ---
 drivers/gpu/drm/vmwgfx/vmwgfx_ldu.c | 45 +++++++++++++++++----
 3 files changed, 38 insertions(+), 74 deletions(-)

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
index 84d6380b9895..866bc3bd157a 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
@@ -1396,70 +1396,10 @@ static void vmw_framebuffer_bo_destroy(struct drm_framebuffer *framebuffer)
 	kfree(vfbd);
 }
 
-static int vmw_framebuffer_bo_dirty(struct drm_framebuffer *framebuffer,
-				    struct drm_file *file_priv,
-				    unsigned int flags, unsigned int color,
-				    struct drm_clip_rect *clips,
-				    unsigned int num_clips)
-{
-	struct vmw_private *dev_priv = vmw_priv(framebuffer->dev);
-	struct vmw_framebuffer_bo *vfbd =
-		vmw_framebuffer_to_vfbd(framebuffer);
-	struct drm_clip_rect norect;
-	int ret, increment = 1;
-
-	drm_modeset_lock_all(&dev_priv->drm);
-
-	if (!num_clips) {
-		num_clips = 1;
-		clips = &norect;
-		norect.x1 = norect.y1 = 0;
-		norect.x2 = framebuffer->width;
-		norect.y2 = framebuffer->height;
-	} else if (flags & DRM_MODE_FB_DIRTY_ANNOTATE_COPY) {
-		num_clips /= 2;
-		increment = 2;
-	}
-
-	switch (dev_priv->active_display_unit) {
-	case vmw_du_legacy:
-		ret = vmw_kms_ldu_do_bo_dirty(dev_priv, &vfbd->base, 0, 0,
-					      clips, num_clips, increment);
-		break;
-	default:
-		ret = -EINVAL;
-		WARN_ONCE(true, "Dirty called with invalid display system.\n");
-		break;
-	}
-
-	vmw_cmd_flush(dev_priv, false);
-
-	drm_modeset_unlock_all(&dev_priv->drm);
-
-	return ret;
-}
-
-static int vmw_framebuffer_bo_dirty_ext(struct drm_framebuffer *framebuffer,
-					struct drm_file *file_priv,
-					unsigned int flags, unsigned int color,
-					struct drm_clip_rect *clips,
-					unsigned int num_clips)
-{
-	struct vmw_private *dev_priv = vmw_priv(framebuffer->dev);
-
-	if (dev_priv->active_display_unit == vmw_du_legacy &&
-	    vmw_cmd_supported(dev_priv))
-		return vmw_framebuffer_bo_dirty(framebuffer, file_priv, flags,
-						color, clips, num_clips);
-
-	return drm_atomic_helper_dirtyfb(framebuffer, file_priv, flags, color,
-					 clips, num_clips);
-}
-
 static const struct drm_framebuffer_funcs vmw_framebuffer_bo_funcs = {
 	.create_handle = vmw_framebuffer_bo_create_handle,
 	.destroy = vmw_framebuffer_bo_destroy,
-	.dirty = vmw_framebuffer_bo_dirty_ext,
+	.dirty = drm_atomic_helper_dirtyfb,
 };
 
 /**
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.h b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.h
index 3de7b4b6a230..db81e635dc06 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.h
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.h
@@ -507,11 +507,6 @@ void vmw_du_connector_destroy_state(struct drm_connector *connector,
  */
 int vmw_kms_ldu_init_display(struct vmw_private *dev_priv);
 int vmw_kms_ldu_close_display(struct vmw_private *dev_priv);
-int vmw_kms_ldu_do_bo_dirty(struct vmw_private *dev_priv,
-			    struct vmw_framebuffer *framebuffer,
-			    unsigned int flags, unsigned int color,
-			    struct drm_clip_rect *clips,
-			    unsigned int num_clips, int increment);
 int vmw_kms_update_proxy(struct vmw_resource *res,
 			 const struct drm_clip_rect *clips,
 			 unsigned num_clips,
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_ldu.c b/drivers/gpu/drm/vmwgfx/vmwgfx_ldu.c
index c0e42f2ed144..a82fa9700370 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_ldu.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_ldu.c
@@ -275,6 +275,7 @@ static const struct drm_crtc_funcs vmw_legacy_crtc_funcs = {
 	.atomic_duplicate_state = vmw_du_crtc_duplicate_state,
 	.atomic_destroy_state = vmw_du_crtc_destroy_state,
 	.set_config = drm_atomic_helper_set_config,
+	.page_flip = drm_atomic_helper_page_flip,
 };
 
 
@@ -314,6 +315,12 @@ static const struct
 drm_connector_helper_funcs vmw_ldu_connector_helper_funcs = {
 };
 
+static int vmw_kms_ldu_do_bo_dirty(struct vmw_private *dev_priv,
+				   struct vmw_framebuffer *framebuffer,
+				   unsigned int flags, unsigned int color,
+				   struct drm_mode_rect *clips,
+				   unsigned int num_clips);
+
 /*
  * Legacy Display Plane Functions
  */
@@ -332,7 +339,6 @@ vmw_ldu_primary_plane_atomic_update(struct drm_plane *plane,
 	struct drm_framebuffer *fb;
 	struct drm_crtc *crtc = new_state->crtc ?: old_state->crtc;
 
-
 	ldu = vmw_crtc_to_ldu(crtc);
 	dev_priv = vmw_priv(plane->dev);
 	fb       = new_state->fb;
@@ -345,8 +351,31 @@ vmw_ldu_primary_plane_atomic_update(struct drm_plane *plane,
 		vmw_ldu_del_active(dev_priv, ldu);
 
 	vmw_ldu_commit_list(dev_priv);
-}
 
+	if (vfb && vmw_cmd_supported(dev_priv)) {
+		struct drm_mode_rect fb_rect = {
+			.x1 = 0,
+			.y1 = 0,
+			.x2 = vfb->base.width,
+			.y2 = vfb->base.height
+		};
+		struct drm_mode_rect *damage_rects = drm_plane_get_damage_clips(new_state);
+		u32 rect_count = drm_plane_get_damage_clips_count(new_state);
+		int ret;
+
+		if (!damage_rects) {
+			damage_rects = &fb_rect;
+			rect_count = 1;
+		}
+
+		ret = vmw_kms_ldu_do_bo_dirty(dev_priv, vfb, 0, 0, damage_rects, rect_count);
+
+		drm_WARN_ONCE(plane->dev, ret,
+			"vmw_kms_ldu_do_bo_dirty failed with: ret=%d\n", ret);
+
+		vmw_cmd_flush(dev_priv, false);
+	}
+}
 
 static const struct drm_plane_funcs vmw_ldu_plane_funcs = {
 	.update_plane = drm_atomic_helper_update_plane,
@@ -577,11 +606,11 @@ int vmw_kms_ldu_close_display(struct vmw_private *dev_priv)
 }
 
 
-int vmw_kms_ldu_do_bo_dirty(struct vmw_private *dev_priv,
-			    struct vmw_framebuffer *framebuffer,
-			    unsigned int flags, unsigned int color,
-			    struct drm_clip_rect *clips,
-			    unsigned int num_clips, int increment)
+static int vmw_kms_ldu_do_bo_dirty(struct vmw_private *dev_priv,
+				   struct vmw_framebuffer *framebuffer,
+				   unsigned int flags, unsigned int color,
+				   struct drm_mode_rect *clips,
+				   unsigned int num_clips)
 {
 	size_t fifo_size;
 	int i;
@@ -597,7 +626,7 @@ int vmw_kms_ldu_do_bo_dirty(struct vmw_private *dev_priv,
 		return -ENOMEM;
 
 	memset(cmd, 0, fifo_size);
-	for (i = 0; i < num_clips; i++, clips += increment) {
+	for (i = 0; i < num_clips; i++, clips++) {
 		cmd[i].header = SVGA_CMD_UPDATE;
 		cmd[i].body.x = clips->x1;
 		cmd[i].body.y = clips->y1;
-- 
2.38.1

Re: [PATCH 2/3] drm/vmwgfx: Print errors when running on broken/unsupported configs

[Martin Krastev (VMware)]

From: Martin Krastev <krastevm@vmware.com>


LGTM!

Reviewed-by: Martin Krastev <krastevm@vmware.com>


Regards,

Martin


On 21.03.23 г. 4:09 ч., Zack Rusin wrote:
> From: Zack Rusin <zackr@vmware.com>
>
> virtualbox implemented an incomplete version of the svga device which
> they decided to drop soon after the initial release. The device was
> always broken in various ways and never supported by vmwgfx.
>
> vmwgfx should refuse to load on those configurations but currently
> drm has no way of reloading fbdev when the specific pci driver refuses
> to load, which would leave users without a usable fb. Instead of
> refusing to load print an error and disable a bunch of functionality
> that virtualbox never implemented to at least get fb to work on their
> setup.
>
> Signed-off-by: Zack Rusin <zackr@vmware.com>
> ---
>   drivers/gpu/drm/vmwgfx/vmwgfx_drv.c | 29 +++++++++++++++++++++++++++++
>   drivers/gpu/drm/vmwgfx/vmwgfx_drv.h |  2 ++
>   drivers/gpu/drm/vmwgfx/vmwgfx_msg.c |  9 +++++++++
>   3 files changed, 40 insertions(+)
>
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
> index 2588615a2a38..8b24ecf60e3e 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
> @@ -45,6 +45,9 @@
>   #include <drm/ttm/ttm_placement.h>
>   #include <generated/utsrelease.h>
>   
> +#ifdef CONFIG_X86
> +#include <asm/hypervisor.h>
> +#endif
>   #include <linux/cc_platform.h>
>   #include <linux/dma-mapping.h>
>   #include <linux/module.h>
> @@ -897,6 +900,16 @@ static int vmw_driver_load(struct vmw_private *dev_priv, u32 pci_id)
>   				 cap2_names, ARRAY_SIZE(cap2_names));
>   	}
>   
> +	if (!vmwgfx_supported(dev_priv)) {
> +		vmw_disable_backdoor();
> +		drm_err_once(&dev_priv->drm,
> +			     "vmwgfx seems to be running on an unsupported hypervisor.");
> +		drm_err_once(&dev_priv->drm,
> +			     "This configuration is likely broken.");
> +		drm_err_once(&dev_priv->drm,
> +			     "Please switch to a supported graphics device to avoid problems.");
> +	}
> +
>   	ret = vmw_dma_select_mode(dev_priv);
>   	if (unlikely(ret != 0)) {
>   		drm_info(&dev_priv->drm,
> @@ -1320,6 +1333,22 @@ static void vmw_master_drop(struct drm_device *dev,
>   	vmw_kms_legacy_hotspot_clear(dev_priv);
>   }
>   
> +bool vmwgfx_supported(struct vmw_private *vmw)
> +{
> +#if defined(CONFIG_X86)
> +	return hypervisor_is_type(X86_HYPER_VMWARE);
> +#elif defined(CONFIG_ARM64)
> +	/*
> +	 * On aarch64 only svga3 is supported
> +	 */
> +	return vmw->pci_id == VMWGFX_PCI_ID_SVGA3;
> +#else
> +	drm_warn_once(&vmw->drm,
> +		      "vmwgfx is running on an unknown architecture.");
> +	return false;
> +#endif
> +}
> +
>   /**
>    * __vmw_svga_enable - Enable SVGA mode, FIFO and use of VRAM.
>    *
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
> index fb8f0c0642c0..3810a9984a7f 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
> @@ -773,6 +773,7 @@ static inline u32 vmw_max_num_uavs(struct vmw_private *dev_priv)
>   
>   extern void vmw_svga_enable(struct vmw_private *dev_priv);
>   extern void vmw_svga_disable(struct vmw_private *dev_priv);
> +bool vmwgfx_supported(struct vmw_private *vmw);
>   
>   
>   /**
> @@ -1358,6 +1359,7 @@ int vmw_bo_cpu_blit(struct ttm_buffer_object *dst,
>   		    struct vmw_diff_cpy *diff);
>   
>   /* Host messaging -vmwgfx_msg.c: */
> +void vmw_disable_backdoor(void);
>   int vmw_host_get_guestinfo(const char *guest_info_param,
>   			   char *buffer, size_t *length);
>   __printf(1, 2) int vmw_host_printf(const char *fmt, ...);
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c b/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c
> index ca1a3fe44fa5..2651fe0ef518 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c
> @@ -1179,3 +1179,12 @@ int vmw_mksstat_remove_ioctl(struct drm_device *dev, void *data,
>   
>   	return -EAGAIN;
>   }
> +
> +/**
> + * vmw_disable_backdoor: Disables all backdoor communication
> + * with the hypervisor.
> + */
> +void vmw_disable_backdoor(void)
> +{
> +	vmw_msg_enabled = 0;
> +}

Re: [PATCH 2/3] drm/vmwgfx: Print errors when running on broken/unsupported configs

["Maaz Mombasawala (VMware)]

On 3/20/23 19:09, Zack Rusin wrote:
> From: Zack Rusin <zackr@vmware.com>
> 
> virtualbox implemented an incomplete version of the svga device which
> they decided to drop soon after the initial release. The device was
> always broken in various ways and never supported by vmwgfx.
> 
> vmwgfx should refuse to load on those configurations but currently
> drm has no way of reloading fbdev when the specific pci driver refuses
> to load, which would leave users without a usable fb. Instead of
> refusing to load print an error and disable a bunch of functionality
> that virtualbox never implemented to at least get fb to work on their
> setup.
> 
> Signed-off-by: Zack Rusin <zackr@vmware.com>
> ---
>  drivers/gpu/drm/vmwgfx/vmwgfx_drv.c | 29 +++++++++++++++++++++++++++++
>  drivers/gpu/drm/vmwgfx/vmwgfx_drv.h |  2 ++
>  drivers/gpu/drm/vmwgfx/vmwgfx_msg.c |  9 +++++++++
>  3 files changed, 40 insertions(+)
> 
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
> index 2588615a2a38..8b24ecf60e3e 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
> @@ -45,6 +45,9 @@
>  #include <drm/ttm/ttm_placement.h>
>  #include <generated/utsrelease.h>
>  
> +#ifdef CONFIG_X86
> +#include <asm/hypervisor.h>
> +#endif
>  #include <linux/cc_platform.h>
>  #include <linux/dma-mapping.h>
>  #include <linux/module.h>
> @@ -897,6 +900,16 @@ static int vmw_driver_load(struct vmw_private *dev_priv, u32 pci_id)
>  				 cap2_names, ARRAY_SIZE(cap2_names));
>  	}
>  
> +	if (!vmwgfx_supported(dev_priv)) {
> +		vmw_disable_backdoor();
> +		drm_err_once(&dev_priv->drm,
> +			     "vmwgfx seems to be running on an unsupported hypervisor.");
> +		drm_err_once(&dev_priv->drm,
> +			     "This configuration is likely broken.");
> +		drm_err_once(&dev_priv->drm,
> +			     "Please switch to a supported graphics device to avoid problems.");
> +	}
> +
>  	ret = vmw_dma_select_mode(dev_priv);
>  	if (unlikely(ret != 0)) {
>  		drm_info(&dev_priv->drm,
> @@ -1320,6 +1333,22 @@ static void vmw_master_drop(struct drm_device *dev,
>  	vmw_kms_legacy_hotspot_clear(dev_priv);
>  }
>  
> +bool vmwgfx_supported(struct vmw_private *vmw)
> +{
> +#if defined(CONFIG_X86)
> +	return hypervisor_is_type(X86_HYPER_VMWARE);
> +#elif defined(CONFIG_ARM64)
> +	/*
> +	 * On aarch64 only svga3 is supported
> +	 */
> +	return vmw->pci_id == VMWGFX_PCI_ID_SVGA3;
> +#else
> +	drm_warn_once(&vmw->drm,
> +		      "vmwgfx is running on an unknown architecture.");
> +	return false;
> +#endif
> +}
> +
>  /**
>   * __vmw_svga_enable - Enable SVGA mode, FIFO and use of VRAM.
>   *
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
> index fb8f0c0642c0..3810a9984a7f 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
> @@ -773,6 +773,7 @@ static inline u32 vmw_max_num_uavs(struct vmw_private *dev_priv)
>  
>  extern void vmw_svga_enable(struct vmw_private *dev_priv);
>  extern void vmw_svga_disable(struct vmw_private *dev_priv);
> +bool vmwgfx_supported(struct vmw_private *vmw);
>  
>  
>  /**
> @@ -1358,6 +1359,7 @@ int vmw_bo_cpu_blit(struct ttm_buffer_object *dst,
>  		    struct vmw_diff_cpy *diff);
>  
>  /* Host messaging -vmwgfx_msg.c: */
> +void vmw_disable_backdoor(void);
>  int vmw_host_get_guestinfo(const char *guest_info_param,
>  			   char *buffer, size_t *length);
>  __printf(1, 2) int vmw_host_printf(const char *fmt, ...);
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c b/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c
> index ca1a3fe44fa5..2651fe0ef518 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c
> @@ -1179,3 +1179,12 @@ int vmw_mksstat_remove_ioctl(struct drm_device *dev, void *data,
>  
>  	return -EAGAIN;
>  }
> +
> +/**
> + * vmw_disable_backdoor: Disables all backdoor communication
> + * with the hypervisor.
> + */
> +void vmw_disable_backdoor(void)
> +{
> +	vmw_msg_enabled = 0;
> +}


LGTM

Reviewed-by: Maaz Mombasawala <mombasawalam@vmware.com>

-- 
Maaz Mombasawala (VMware) <maazm@fastmail.com>