On 11/4/22 4:48 PM, Borislav Petkov wrote:
On Fri, Nov 04, 2022 at 04:36:49PM -0500, Kim Phillips wrote:
AMD Zen4 processors advertise features in this leaf.
Add the leaf and its Automatic IBRS feature bit.
Note: New whole leaf (vs a bit) due to propagation via KVM
later in this series.
No, not a separate leaf - use scattered.c
> For an example what to do for KVM, see
https://lore.kernel.org/r/20221103025030.78371-1-jiaxi.chen@xxxxxxxxxxxxxxx
That adds features that are mutually exclusive between
kvm and the host kernel, unlike AUTOIBRS.
When trying to wire up a scattered host AUTOIBRS version up to
kvm, I couldn't get past all the reverse_cpuid_check()
BUILD_BUGs demanding exclusivity between h/w and "Linux"
(s/w) FEATUREs.
Is there an example of a scattered feature that gets both its
boot_cpu_has() and guest_cpuid_has() satisfied in the same build?
If not, I'll resubmit like this original submission - AUTOIBRS in
a separate h/w leaf.
Thanks,
Kim
