vmwgfx: Avoid HW operations when not master

Note that for DRI2, a dri2_copy_region becomes a NOP when not master.
Additionally, all dri2 operations that lead to a potential kernel
access will return FALSE.

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

6 files changed, 75 insertions, 1 deletions

diff --git a/vmwgfx/vmwgfx_dri2.c b/vmwgfx/vmwgfx_dri2.c
index 2f007f0..57f2d9d 100644
--- a/vmwgfx/vmwgfx_dri2.c
+++ b/vmwgfx/vmwgfx_dri2.c
@@ -138,6 +138,8 @@ dri2_do_create_buffer(DrawablePtr pDraw, DRI2Buffer2Ptr buffer, unsigned int for
       return TRUE;
     case DRI2BufferStencil:
     case DRI2BufferDepthStencil:
+	if (!pScrn->vtSema)
+	    return FALSE;
 
 	depth = (format) ? vmwgfx_zs_format_to_depth(format) : 32;
 
@@ -155,6 +157,9 @@ dri2_do_create_buffer(DrawablePtr pDraw, DRI2Buffer2Ptr buffer, unsigned int for
 
        break;
     case DRI2BufferDepth:
+	if (!pScrn->vtSema)
+	    return FALSE;
+
 	depth = (format) ? vmwgfx_z_format_to_depth(format) :
 	    pDraw->bitsPerPixel;
 
@@ -291,6 +296,14 @@ dri2_copy_region(DrawablePtr pDraw, RegionPtr pRegion,
     DrawablePtr dst_draw;
     RegionPtr myClip;
     GCPtr gc;
+    ScrnInfoPtr pScrn = xf86ScreenToScrn(pScreen);
+
+    /*
+     * This is a fragile protection against HW operations when not master.
+     * Needs to be blocked higher up in the dri2 code.
+     */
+    if (!pScrn->vtSema)
+	return;
 
     /*
      * In driCreateBuffers we dewrap windows into the
diff --git a/vmwgfx/vmwgfx_driver.c b/vmwgfx/vmwgfx_driver.c
index 3002285..eeaea4b 100644
--- a/vmwgfx/vmwgfx_driver.c
+++ b/vmwgfx/vmwgfx_driver.c
@@ -1116,6 +1116,7 @@ drv_leave_vt(VT_FUNC_ARGS_DECL)
 
     vmwgfx_cursor_bypass(ms->fd, 0, 0);
     vmwgfx_disable_scanout(pScrn);
+    vmwgfx_saa_drop_master(pScrn->pScreen);
 
     if (drmDropMaster(ms->fd))
 	xf86DrvMsg(pScrn->scrnIndex, X_WARNING,
@@ -1136,6 +1137,8 @@ drv_enter_vt(VT_FUNC_ARGS_DECL)
     if (!drv_set_master(pScrn))
 	return FALSE;
 
+    vmwgfx_saa_set_master(pScrn->pScreen);
+
     if (!xf86SetDesiredModes(pScrn))
 	return FALSE;
 
diff --git a/vmwgfx/vmwgfx_saa.c b/vmwgfx/vmwgfx_saa.c
index ed3c1ee..5534ca3 100644
--- a/vmwgfx/vmwgfx_saa.c
+++ b/vmwgfx/vmwgfx_saa.c
@@ -423,6 +423,7 @@ vmwgfx_create_pixmap(struct saa_driver *driver, struct saa_pixmap *spix,
 
     WSBMINITLISTHEAD(&vpix->sync_x_head);
     WSBMINITLISTHEAD(&vpix->scanout_list);
+    WSBMINITLISTHEAD(&vpix->pixmap_list);
 
     return TRUE;
 }
@@ -499,6 +500,7 @@ vmwgfx_destroy_pixmap(struct saa_driver *driver, PixmapPtr pixmap)
      */
 
     vmwgfx_pixmap_remove_present(vpix);
+    WSBMLISTDELINIT(&vpix->pixmap_list);
     WSBMLISTDELINIT(&vpix->sync_x_head);
 
     if (vpix->hw_is_dri2_fronts)
@@ -627,6 +629,8 @@ vmwgfx_modify_pixmap_header (PixmapPtr pixmap, int w, int h, int depth,
 			     int bpp, int devkind, void *pixdata)
 {
     struct vmwgfx_saa_pixmap *vpix = vmwgfx_saa_pixmap(pixmap);
+    ScreenPtr pScreen = pixmap->drawable.pScreen;
+    struct vmwgfx_saa *vsaa = to_vmwgfx_saa(saa_get_driver(pScreen));
     unsigned int old_height;
     unsigned int old_width;
     unsigned int old_pitch;
@@ -670,6 +674,8 @@ vmwgfx_modify_pixmap_header (PixmapPtr pixmap, int w, int h, int depth,
 
     vmwgfx_pix_resize(pixmap, old_pitch, old_height, old_width);
     vmwgfx_pixmap_free_storage(vpix);
+    WSBMLISTADDTAIL(&vpix->pixmap_list, &vsaa->pixmaps);
+
     return TRUE;
 
   out_no_modify:
@@ -860,7 +866,7 @@ vmwgfx_copy_prepare(struct saa_driver *driver,
     Bool has_valid_hw;
 
     if (!vsaa->xat || !SAA_PM_IS_SOLID(&dst_pixmap->drawable, plane_mask) ||
-	alu != GXcopy)
+	alu != GXcopy || !vsaa->is_master)
 	return FALSE;
 
     src_vpix = vmwgfx_saa_pixmap(src_pixmap);
@@ -1057,6 +1063,9 @@ vmwgfx_composite_prepare(struct saa_driver *driver, CARD8 op,
     RegionRec empty;
     struct xa_composite *xa_comp;
 
+    if (!vsaa->is_master)
+	return FALSE;
+
     REGION_NULL(pScreen, &empty);
 
     /*
@@ -1367,7 +1376,9 @@ vmwgfx_saa_init(ScreenPtr pScreen, int drm_fd, struct xa_tracker *xat,
     vsaa->use_present_opt = direct_presents;
     vsaa->only_hw_presents = only_hw_presents;
     vsaa->rendercheck = rendercheck;
+    vsaa->is_master = TRUE;
     WSBMINITLISTHEAD(&vsaa->sync_x_list);
+    WSBMINITLISTHEAD(&vsaa->pixmaps);
 
     vsaa->driver = vmwgfx_saa_driver;
     vsaa->vcomp = vmwgfx_alloc_composite();
@@ -1518,3 +1529,34 @@ vmwgfx_scanout_unref(struct vmwgfx_screen_entry *entry)
     entry->pixmap = NULL;
     pixmap->drawable.pScreen->DestroyPixmap(pixmap);
 }
+
+void
+vmwgfx_saa_set_master(ScreenPtr pScreen)
+{
+    struct vmwgfx_saa *vsaa = to_vmwgfx_saa(saa_get_driver(pScreen));
+
+    vsaa->is_master = TRUE;
+}
+
+void
+vmwgfx_saa_drop_master(ScreenPtr pScreen)
+{
+    struct vmwgfx_saa *vsaa = to_vmwgfx_saa(saa_get_driver(pScreen));
+    struct _WsbmListHead *list;
+    struct vmwgfx_saa_pixmap *vpix;
+    struct saa_pixmap *spix;
+
+    WSBMLISTFOREACH(list, &vsaa->pixmaps) {
+	vpix = WSBMLISTENTRY(list, struct vmwgfx_saa_pixmap, pixmap_list);
+	spix = &vpix->base;
+
+	if (!vpix->hw)
+	    continue;
+
+	(void) vmwgfx_download_from_hw(&vsaa->driver, spix->pixmap,
+				       &spix->dirty_hw);
+	REGION_EMPTY(draw->pScreen, &spix->dirty_hw);
+    }
+
+    vsaa->is_master = FALSE;
+}
diff --git a/vmwgfx/vmwgfx_saa.h b/vmwgfx/vmwgfx_saa.h
index bb8ec96..d8aa3d3 100644
--- a/vmwgfx/vmwgfx_saa.h
+++ b/vmwgfx/vmwgfx_saa.h
@@ -54,6 +54,7 @@ struct vmwgfx_saa_pixmap {
     int hw_is_dri2_fronts;
     struct _WsbmListHead sync_x_head;
     struct _WsbmListHead scanout_list;
+    struct _WsbmListHead pixmap_list;
 
     uint32_t xa_flags;
     uint32_t staging_add_flags;
@@ -107,4 +108,11 @@ Bool
 vmwgfx_hw_accel_validate(PixmapPtr pixmap, unsigned int depth,
 			 uint32_t add_flags, uint32_t remove_flags,
 			 RegionPtr region);
+
+void
+vmwgfx_saa_set_master(ScreenPtr pScreen);
+
+void
+vmwgfx_saa_drop_master(ScreenPtr pScreen);
+
 #endif
diff --git a/vmwgfx/vmwgfx_saa_priv.h b/vmwgfx/vmwgfx_saa_priv.h
index 5f46dee..16583b0 100644
--- a/vmwgfx/vmwgfx_saa_priv.h
+++ b/vmwgfx/vmwgfx_saa_priv.h
@@ -54,8 +54,10 @@ struct vmwgfx_saa {
     Bool use_present_opt;
     Bool only_hw_presents;
     Bool rendercheck;
+    Bool is_master;
     void (*present_flush) (ScreenPtr pScreen);
     struct _WsbmListHead sync_x_list;
+    struct _WsbmListHead pixmaps;
     struct vmwgfx_composite *vcomp;
 };
 
diff --git a/vmwgfx/vmwgfx_xa_surface.c b/vmwgfx/vmwgfx_xa_surface.c
index 8b30e45..2f23c57 100644
--- a/vmwgfx/vmwgfx_xa_surface.c
+++ b/vmwgfx/vmwgfx_xa_surface.c
@@ -362,6 +362,12 @@ vmwgfx_hw_accel_validate(PixmapPtr pixmap, unsigned int depth,
 Bool
 vmwgfx_hw_dri2_validate(PixmapPtr pixmap, unsigned int depth)
 {
+    struct vmwgfx_saa *vsaa =
+	to_vmwgfx_saa(saa_get_driver(pixmap->drawable.pScreen));
+
+    if (!vsaa->is_master)
+	    return FALSE;
+
     return (vmwgfx_hw_dri2_stage(pixmap, depth) &&
 	    vmwgfx_hw_commit(pixmap) &&
 	    vmwgfx_hw_validate(pixmap, NULL));