On 9/30/24 16:11, Pavan Kumar Paluri wrote: > Provide "nosnp" boot option via "sev=nosnp" kernel command line to > prevent SEV-SNP[1] capable host kernel from enabling SEV-SNP and > initializing Reverse Map Table (RMP) [1]. > > On providing sev=nosnp via kernel command line: > cat /sys/module/kvm_amd/parameters/sev_snp should be "N". I don't see any mention in the changelog, cover letter or Documentation/ about why someone would want to do this. I assume it's because of performance (walking the RMP table is non-zero cost). The BIOS allocates the RMP table, right? So this option presumably gets the performance back, but not the memory. That's probably also worth mentioning ... somewhere.
