On 1/21/21 5:51 PM, Babu Moger wrote: > > > On 1/20/21 9:10 PM, Babu Moger wrote: >> >> >> On 1/20/21 3:45 PM, Babu Moger wrote: >>> >>> >>> On 1/20/21 3:14 PM, Jim Mattson wrote: >>>> On Tue, Jan 19, 2021 at 3:45 PM Babu Moger <babu.moger@xxxxxxx> wrote: >>>>> >>>>> >>>>> >>>>> On 1/19/21 5:01 PM, Jim Mattson wrote: >>>>>> On Mon, Sep 14, 2020 at 11:33 AM Babu Moger <babu.moger@xxxxxxx> wrote: >>>>>> >>>>>>> Thanks Paolo. Tested Guest/nested guest/kvm units tests. Everything works >>>>>>> as expected. >>>>>> >>>>>> Debian 9 does not like this patch set. As a kvm guest, it panics on a >>>>>> Milan CPU unless booted with 'nopcid'. Gmail mangles long lines, so >>>>>> please see the attached kernel log snippet. Debian 10 is fine, so I >>>>>> assume this is a guest bug. >>>>>> >>>>> >>>>> We had an issue with PCID feature earlier. This was showing only with SEV >>>>> guests. It is resolved recently. Do you think it is not related that? >>>>> Here are the patch set. >>>>> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore.kernel.org%2Fkvm%2F160521930597.32054.4906933314022910996.stgit%40bmoger-ubuntu%2F&data=04%7C01%7CBabu.Moger%40amd.com%7C3009e5f7f32b4dbd4aee08d8bdc045c9%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637467980841376327%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=%2Bva7em372XD7uaCrSy3UBH6a9n8xaTTXWCAlA3gJX78%3D&reserved=0 >>>> >>>> The Debian 9 release we tested is not an SEV guest. >>> ok. I have not tested Debian 9 before. I will try now. Will let you know >>> how it goes. thanks >>> >> >> I have reproduced the issue locally. Will investigate. thanks >> > Few updates. > 1. Like Jim mentioned earlier, this appears to be guest kernel issue. > Debian 9 runs the base kernel 4.9.0-14. Problem can be seen consistently > with this kernel. > > 2. This guest kernel(4.9.0-14) does not like the new feature INVPCID. > > 3. System comes up fine when invpcid feature is disabled with the boot > parameter "noinvpcid" and also with "nopcid". nopcid disables both pcid > and invpcid. > > 4. Upgraded the guest kernel to v5.0 and system comes up fine. > > 5. Also system comes up fine with latest guest kernel 5.11.0-rc4. > > I did not bisect further yet. > Babu > Thanks Some more update: System comes up fine with kernel v4.9(checked out on upstream tag v4.9). So, I am assuming this is something specific to Debian 4.9.0-14 kernel. Note: I couldn't go back prior versions(v4.8 or earlier) due to compile issues. Thanks Babu
