Bug 1822682 - [Azure]QEMU-4.2 fails to start a VM on Azure (MSR 0x48b)
Summary: [Azure]QEMU-4.2 fails to start a VM on Azure (MSR 0x48b)
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Red Hat Enterprise Linux Advanced Virtualization
Classification: Red Hat
Component: qemu-kvm
Version: 8.2
Hardware: Unspecified
OS: Unspecified
urgent
urgent
Target Milestone: rc
: 8.2
Assignee: Vitaly Kuznetsov
QA Contact: HuijingHei
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2020-04-09 15:39 UTC by Vitaly Kuznetsov
Modified: 2020-07-01 17:26 UTC (History)
18 users (show)

Fixed In Version: qemu-kvm-4.2.0-19.module+el8.2.0+6296+6b821950
Doc Type: If docs needed, set a value
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Clone Of:
Environment:
Last Closed: 2020-05-05 09:59:02 UTC
Type: Bug
Target Upstream Version:
Embargoed:


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Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHBA-2020:2017 0 None None None 2020-05-05 09:59:45 UTC

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


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