From 44032a443bd65bd7113a74dc797c210a67236e92 Mon Sep 17 00:00:00 2001
From: Zack Rusin <zackr@vmware.com>
Date: Fri, 18 Mar 2022 13:43:31 -0400
Subject: drm/vmwgfx: Disable command buffers on svga3 without gbobjects
Git-commit: 21d1d192890ced87f2f04f8f4dea92406e0b162a
Patch-mainline: v5.18-rc7
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

With very limited vram on svga3 it's difficult to handle all the surface
migrations. Without gbobjects, i.e. the ability to store surfaces in
guest mobs, there's no reason to support intermediate svga2 features,
especially because we can fall back to fb traces and svga3 will never
support those in-between features.

On svga3 we wither want to use fb traces or screen targets
(i.e. gbobjects), nothing in between. This fixes presentation on a lot
of fusion/esxi tech previews where the exposed svga3 caps haven't been
finalized yet.

Signed-off-by: Zack Rusin <zackr@vmware.com>
Fixes: 2cd80dbd3551 ("drm/vmwgfx: Add basic support for SVGA3")
Cc: <stable@vger.kernel.org> # v5.14+
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220318174332.440068-5-zack@kde.org
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/vmwgfx/vmwgfx_cmd.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_cmd.c b/drivers/gpu/drm/vmwgfx/vmwgfx_cmd.c
index bf1b394753da..162dfeb1cc5a 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_cmd.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_cmd.c
@@ -675,11 +675,14 @@ int vmw_cmd_emit_dummy_query(struct vmw_private *dev_priv,
  */
 bool vmw_cmd_supported(struct vmw_private *vmw)
 {
-	if ((vmw->capabilities & (SVGA_CAP_COMMAND_BUFFERS |
-				  SVGA_CAP_CMD_BUFFERS_2)) != 0)
-		return true;
+	bool has_cmdbufs =
+		(vmw->capabilities & (SVGA_CAP_COMMAND_BUFFERS |
+				      SVGA_CAP_CMD_BUFFERS_2)) != 0;
+	if (vmw_is_svga_v3(vmw))
+		return (has_cmdbufs &&
+			(vmw->capabilities & SVGA_CAP_GBOBJECTS) != 0);
 	/*
 	 * We have FIFO cmd's
 	 */
-	return vmw->fifo_mem != NULL;
+	return has_cmdbufs || vmw->fifo_mem != NULL;
 }
-- 
2.38.1