On Thu Dec 11, 2025 at 4:38 PM CET, Andrew Cooper wrote: > On 11/12/2025 10:31 am, Alejandro Vallejo wrote: >> Seeing how both you and Andrew seem onboard with dropping cross-vendor >> support > > I found another cross-vendor dropping which you'll want to look into. > > struct svm_vcpu contains three guest_sysenter_* MSRs. > > In AMD CPUs, these MSRs only have 32 bits of storage, with the upper > halfs write-discard. They are switched via VMLOAD/VMSAVE. > > However, in the cross-vendor case, the upper halves are needed for 64bit > kernels setting up SYSENTER support. Therefore, they're unconditionally > intercepted so we can avoid losing the upper half. > > By dropping cross-vendor support, we can get rid of these fields, allow > the guest unconditional access, and simply the MSR intercept logic a little. > > ~Andrew
Sounds straightforward, I'll add it to the pile. Cheers, Alejandro
