6 May
2025
6 May
'25
1:04 a.m.
On Sat, Apr 26, 2025, Borislav Petkov wrote:
On April 26, 2025 3:08:29 AM GMT+03:00, Sean Christopherson seanjc@google.com wrote:
No, that would defeat the purpose of the check. The X86_FEATURE_HYPERVISOR has nothing to do with correctness, it's all about performance. Critically, it's a static check that gets patched at runtime. It's a micro-optimization for bare metal to avoid a single cache miss (the __this_cpu_read(cpu_dr7)). Routing through cc_platform_has() would be far, far heavier than calling hw_breakpoint_active().
Huh, we care so much about speed here?
That's a PeterZ question :-)