On Tue, Dec 08 2020 at 15:12, Marcelo Tosatti wrote:
On Tue, Dec 08, 2020 at 06:25:13PM +0200, Maxim Levitsky wrote:
On Tue, 2020-12-08 at 17:02 +0100, Thomas Gleixner wrote: The "bug" is that if VMM moves a hardware time counter (tsc or anything else) forward by large enough value in one go, then the guest kernel will supposingly have an overflow in the time code. I don't consider this to be a buggy VMM behavior, but rather a kernel bug that should be fixed (if this bug actually exists)
It exists.
In the VMM.
We are talking about the fact that TSC can jump forward by arbitrary large value if the migration took arbitrary amount of time, which (assuming that the bug is real) can crash the guest kernel.
QE reproduced it.
Sure, that's what QE is about. Just your conclusion is wrong.
Thanks,
tglx