Re: [PATCH v6 00/12] SVM cleanup and INVPCID feature support

[Babu Moger]

On 3/11/21 3:40 PM, Borislav Petkov wrote:
> On Thu, Mar 11, 2021 at 02:57:04PM -0600, Babu Moger wrote:
>>  It is related PCID and INVPCID combination. Few more details.
>>  1. System comes up fine with "noinvpid". So, it happens when invpcid is
>> enabled.
> 
> Which system, host or guest?
> 
>>  2. Host is coming up fine. Problem is with the guest.
> 
> Aha, guest.
> 
>>  3. Problem happens with Debian 9. Debian kernel version is 4.9.0-14.
>>  4. Debian 10 is fine.
>>  5. Upstream kernels are fine. Tried on v5.11 and it is working fine.
>>  6. Git bisect pointed to commit 47811c66356d875e76a6ca637a9d384779a659bb.
>>
>>  Let me know if want me to try something else.
> 
> Yes, I assume host has the patches which belong to this thread?

Yes. Host has all these patches. Right now I am on 5.12.0-rc2. I just
updated yesterday. I was able to reproduce 5.11 also.


> 
> So please describe:
> 
> 1. host has these patches, cmdline params, etc.

# cat /proc/cmdline
BOOT_IMAGE=(hd0,gpt2)/vmlinuz-5.12.0-rc2+ root=/dev/mapper/rhel-root ro
crashkernel=auto resume=/dev/mapper/rhel-swap rd.lvm.lv=rhel/root
rd.lvm.lv=rhel/swap ras=cec_disable nmi_watchdog=0 warn_ud2=on selinux=0
earlyprintk=serial,ttyS1,115200n8 console=ttyS1,115200n8


> 2. guest is a 4.9 kernel, cmdline params, etc.

I use qemu command line to bring up the guest. Make sure to use "-cpu host".

qemu-system-x86_64 -name deb9 -m 16384 -smp cores=16,threads=1,sockets=1
-hda vdisk-deb.qcow2 -enable-kvm -net nic  -net
bridge,br=virbr0,helper=/usr/libexec/qemu-bridge-helper -cpu host,+svm
-nographic


The grub command line looks like this on the guest.

cat /proc/cmdline
BOOT_IMAGE=/boot/vmlinuz-4.9.0-14-amd64
root=UUID=a0069240-cd60-4795-a391-273266dbae29 ro console=ttyS0,112500n8
earlyprintk