On Thu, Jun 01 2023 at 10:56, Peter Zijlstra wrote: > On Thu, Jun 01, 2023 at 01:45:35PM +0500, Muhammad Usama Anjum wrote: >> We are thinking of saving and restoring the timestamp counter at suspend >> and resume time respectively. In theory it can work on Intel because of >> TSC_ADJUST register. But it'll never work on AMD until: >> * AMD supports the same kind of adjust register. (AMD has said that the >> adjust register cannot be implemented in their firmware. They'll have to >> add it to their hardware.) >> * by manual synchronization in kernel (I know you don't like this idea. But >> there is something Windows is doing to save/restore and sync the TSC) > > Wine could set TIF_NOTSC, which will cause it to run with CR4.TSD > cleared and cause RDTSC to #GP, at which point you can emulate it. We should ask Microsoft to do the same. That'll fix the direct RDTSC usage quickly. :)
