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A comment on Is Your VirtualBox Reading Your E-Mail? Reconstruction of FrameBuffers from VRAM. Parent comment

Re:Is Your VirtualBox Reading Your E-Mail? Reconstruction of... by datenwolf on Sunday March 22, 2015 @02:18PM (#9247691)
> should they be scrubbing vram as well

Yes, but VRAM is a tricky beast. Modern GPUs actually have MMUs and the VRAM address layout the CPU sees may not cover the whole of the memory of the graphics card.

> What happens if I watch 2 minutes of 1080p video - wouldn't we expect all previous framebuffer data to be flushed at that point ?

No, because the video frames will be queued in a circular buffer and anything outside of that doesn't get touched.

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Re:Is Your VirtualBox Reading Your E-Mail? Reconstruction of... by cesarb on Sunday March 22, 2015 @06:31PM (#9248537)
The only way I can see to reliably scrub VRAM would be to use the GPU as a "dumb framebuffer" (without video acceleration), like in the good old days. Then to scrub what was used in the session it should be enough to draw a black screen, do a page flip, and draw a black screen again.
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