Not directly related to this patch, but why does KVM_DEBUGREG_RELOAD exist?
Commit ae561edeb421 ("KVM: x86: DR0-DR3 are not clear on reset") added it to
ensure DR0-3 are fresh when they're modified through non-standard paths, but I
don't see any reason why the new values_must_ be loaded into hardware. eff_db
needs to be updated, but I don't see why hardware DRs need to be updated unless
hardware breakpoints are active or DR exiting is disabled, and in those cases
updating hardware is handled by KVM_DEBUGREG_WONT_EXIT and KVM_DEBUGREG_BP_ENABLED.