If I would have to guess, I would blame my own commit:
e51bfdb68725 ("KVM: nVMX: Expose RDPMC-exiting only when guest supports PMU”)
As in kvm_intel’s setup_vmcs_config() it can be seen that CPU_BASED_RDPMC_EXITING is required in order for KVM to load.
Therefore, I assume the issue is that now L1 guest is not exposed with CPU_BASED_RDPMC_EXITING.
My patch is suppose to hide CPU_BASED_RDPMC_EXITING from L1 only in case L1 vCPU is not exposed with PMU.
Can you provide more details on the vCPU your setup expose to L1?
Have you explicitly disabled PMU from L1 vCPU?
Can you run “cpuid -r” on shell and post here it’s output?
-Liran
> On 7 May 2019, at 23:45, bugzilla-daemon@xxxxxxxxxxxxxxxxxxx wrote:
>
> https://urldefense.proofpoint.com/v2/url?u=https-3A__bugzilla.kernel.org_show-5Fbug.cgi-3Fid-3D203543&d=DwIDaQ&c=RoP1YumCXCgaWHvlZYR8PZh8Bv7qIrMUB65eapI_JnE&r=Jk6Q8nNzkQ6LJ6g42qARkg6ryIDGQr-yKXPNGZbpTx0&m=cB5pEya2zKbSTvVpkeIHKYlQ1F9qW__mnLe0hXnlBCM&s=O2zSR2K1fTcD1Ps40Q_i-ZmS9tVsPYjupbQmw-LCMPk&e=
>
> Bug ID: 203543
> Summary: Starting with kernel 5.1.0-rc6, kvm_intel can no
> longer be loaded in nested kvm/guests
> Product: Virtualization
> Version: unspecified
> Kernel Version: 5.1.0-rc6
> Hardware: Intel
> OS: Linux
> Tree: Mainline
> Status: NEW
> Severity: blocking
> Priority: P1
> Component: kvm
> Assignee: virtualization_kvm@xxxxxxxxxxxxxxxxxxxx
> Reporter: hilld@xxxxxxxxxxxxxxx
> Regression: No
>
> 1. Please describe the problem:
> Starting with kernel 5.1.0-rc6, kvm_intel can no longer be loaded in nested
> kvm/guests
>
> [root@undercloud-0-rhosp10 ~]# modprobe kvm_intel
> modprobe: ERROR: could not insert 'kvm_intel': Input/output error
>
>
> 2. What is the Version-Release number of the kernel:
> 5.1.0-rc7
>
> 3. Did it work previously in Fedora? If so, what kernel version did the issue
> *first* appear? Old kernels are available for download at
> https://urldefense.proofpoint.com/v2/url?u=https-3A__koji.fedoraproject.org_koji_packageinfo-3FpackageID-3D8&d=DwIDaQ&c=RoP1YumCXCgaWHvlZYR8PZh8Bv7qIrMUB65eapI_JnE&r=Jk6Q8nNzkQ6LJ6g42qARkg6ryIDGQr-yKXPNGZbpTx0&m=cB5pEya2zKbSTvVpkeIHKYlQ1F9qW__mnLe0hXnlBCM&s=1wtgL9MEqhN6ZwOZRMKlcW6LYP3zCgz4-1lh8aXyTWo&e= :
> Yes it seems to have appearded between 5.1.0-rc4 (it worked) and 5.1.0-rc6 (it
> no longer worked)
>
> 4. Can you reproduce this issue? If so, please provide the steps to reproduce
> the issue below:
> Yes, update to 5.1.0-rc6 and try to modprobe kvm_intel inside a guest where the
> VMX capabilities has been exposted
>
>
> 5. Does this problem occur with the latest Rawhide kernel? To install the
> Rawhide kernel, run ``sudo dnf install fedora-repos-rawhide`` followed by
> ``sudo dnf update --enablerepo=rawhide kernel``:
> Yes
>
>
> 6. Are you running any modules that not shipped with directly Fedora's kernel?:
> No
>
> 7. Please attach the kernel logs. You can get the complete kernel log
> for a boot with ``journalctl --no-hostname -k > dmesg.txt``. If the
> issue occurred on a previous boot, use the journalctl ``-b`` flag.
>
> --
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