Linux 6.7 Indicates Disabled AMD SVM Virtualization in /proc/cpuinfo

Phoronix reports that Linux will now indicate via /proc/cpuinfo if AMD virtualization (SVM) is disabled. This is a quality of life improvement for home lab virtualization when using AMD CPUs. Previously, checking for the presence of Intel virtualization support and its status could easily be done by looking at the flags in /proc/cpuinfo. However, SVM was always shown in /proc/cpuinfo regardless of whether it was disabled in the BIOS. This oversight is finally being corrected in the upcoming Linux 6.7 kernel cycle, with the possibility of back-porting the fix to existing kernel series.

The patch, developed by Red Hat’s Paolo Bonzini, has been queued into TIP’s x86/cpu branch. This patch will now read the appropriate MSR to verify if SVM has been disabled on AMD and Hygon processors. If SVM is disabled, the CPU capability will be cleared, and it will no longer show in /proc/cpuinfo. Previously, the only indication of AMD SVM being disabled was appearing in the kernel log or KVM virtualization failing to work. This small but useful change makes it much easier to check if virtualization is available via the widely-used /proc/cpuinfo interface.

Source: Phoronix.