Bug 1822682

Summary: [Azure]QEMU-4.2 fails to start a VM on Azure (MSR 0x48b)
Product: Red Hat Enterprise Linux Advanced Virtualization Reporter: Vitaly Kuznetsov <vkuznets>
Component: qemu-kvmAssignee: Vitaly Kuznetsov <vkuznets>
qemu-kvm sub component: General QA Contact: HuijingHei <hhei>
Status: CLOSED ERRATA Docs Contact:
Severity: urgent    
Priority: urgent CC: cfergeau, coli, ddepaula, dgilbert, hhei, jfreiman, jinzhao, juzhang, knoel, leiwang, mtessun, ribarry, virt-maint, wshi, xuli, yacao, ymao, yuxisun
Version: 8.2   
Target Milestone: rc   
Target Release: 8.2   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: qemu-kvm-4.2.0-19.module+el8.2.0+6296+6b821950 Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2020-05-05 09:59:02 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description Vitaly Kuznetsov 2020-04-09 15:39:19 UTC 
Description of problem:

Kata folks report that QEMU-4.2+ is not able to start a VM on Azure:

with
qemu-system-x86_64: error: failed to set MSR 0x48b to 0x1582e00000000
qemu-system-x86_64: /root/qemu/target/i386/kvm.c:2947: kvm_put_msrs: Assertion 
`ret == cpu->kvm_msr_buf->nmsrs' failed.

(see https://www.mail-archive.com/qemu-devel@nongnu.org/msg665051.html)

this only happens if VMX feature is enabled but this is now the default.

The upstream commit fixing the problem is:

commit 4a910e1f6ab4155ec8b24c49b2585cc486916985
Author: Vitaly Kuznetsov <vkuznets>
Date:   Tue Mar 31 18:27:52 2020 +0200

    target/i386: do not set unsupported VMX secondary execution controls


Version-Release number of selected component (if applicable):
QEMU-4.2+

How reproducible:
Always

Steps to Reproduce:
1. Try starting a VM on Azure (where nested VMX is supported) with e.g. '-cpu host'

Actual results:
QEMU aborts.

Expected results:
VM starts.

Additional info:
Comment 13 Danilo de Paula 2020-04-14 20:11:53 UTC 
Do we have anyone backing a blocker+ request for this. It's very late for 8.2.0
Comment 14 Danilo de Paula 2020-04-14 20:15:53 UTC 
Oh, reading the description is looks like a major issue. I'm requesting it myself.
Comment 21 HuijingHei 2020-04-15 03:23:21 UTC 
Change bug status to verified according to Comment 20
Comment 29 Jens Freimann 2020-04-24 13:41:22 UTC 
The instance type used was n1-standard-4 (4 vCPUs, 15 GB memory)
Comment 32 errata-xmlrpc 2020-05-05 09:59:02 UTC 
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2020:2017
Comment 33 Wei Shi 2020-06-15 03:54:32 UTC 
*** Bug 1843970 has been marked as a duplicate of this bug. ***
Comment 34 Christophe Fergeau 2020-07-01 17:26:42 UTC 
Is this going to be backported to qemu-kvm 2.12? I've been seeing this bug with qemu-kvm-2.12.0-99.module+el8.2.0+5827+8c39933c.x86_64