> > If Enhanced IBRS is selected as the mitigation technique for spectre > > v2, the IBRS bit in SPEC_CTRL MSR is set once at boot time and never > > cleared. Kernel also has to make sure that IBRS bit remains set after > > VMEXIT because the guest might have cleared the bit. This is already > > covered by the existing x86_spec_ctrl_set_guest() and > > x86_spec_ctrl_restore_host() speculation control functions. > > > > Enhanced IBRS still requires IBPB for full mitigation. > > [........] > > > > Note: Based on kernel version "Linux 4.18.17" and to be applied on > > both "Linux 4.18.17" and "Linux 4.14.79". Please note that git am > > doesn't apply this patch smoothly on 4.14.79 because of line fuzz, so > > please use "patch -p1". Didn't want to spam the mailing list by > > sending a duplicate patch and hence sending single patch for two stable > releases. > > > > Sending valid patches is never "spam", don't be afraid to do that. Thanks for explaining it. I will never hesitate again to send valid patches. > I've queued this up now, please verify I got it right. Sure! I looked at the patches and they look good to me. Regards, Sai
