Bug 844583

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marked ack+, qe tried virtio rng build.

Patch(es) available on kernel-2.6.32-298.el6

Test this with both rhel6.3 (kernel-2.6.32-279.el6.x86_64) and rhel6.4 (kernel-2.6.32-348.el6.x86_64) guest kernel. But both can not reproduce the 'guest moved used index from xxx to xxx' error after more than 20 times S3 and S4 alternately.

Steps:
1. build the upstream qemu-kvm as the current rhel6 and rhel7 have no virtio-rng-pci device.

2. Boot guest with "-device virtio-rng-pci,bus=pci.0,addr=0xa,id=rng0".
CLI:
#  ./x86_64-softmmu/qemu-system-x86_64  -enable-kvm -m 2048 -smp 2,sockets=2,cores=1,threads=1 -enable-kvm -name t2-rhel6.4-32 -uuid 61b6c504-5a8b-4fe1-8347-6c929b750dde -k en-us -rtc base=localtime,clock=host,driftfix=slew -no-kvm-pit-reinjection -device piix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2 -device usb-tablet,id=input0 -drive file=/home/rhel6.4-64-virtio-backup.qcow2,if=none,id=disk0,format=qcow2,werror=stop,rerror=stop,aio=native -device ide-drive,bus=ide.0,unit=1,drive=disk0,id=disk0  -drive if=none,media=cdrom,id=drive-ide0-1-0,readonly=on,format=raw -device ide-drive,drive=drive-ide0-1-0,bus=ide.1,unit=0,id=cdrom -netdev tap,vhost=on,id=hostnet0 -device virtio-net-pci,netdev=hostnet0,id=net0,mac=44:37:E6:5E:91:85,bus=pci.0,addr=0x5 -monitor stdio -qmp tcp:0:6666,server,nowait -chardev socket,path=/tmp/isa-serial,server,nowait,id=isa1 -device isa-serial,chardev=isa1,id=isa-serial1 -device virtio-serial-pci,id=virtio-serial0,bus=pci.0,addr=0x8 -chardev socket,id=charchannel0,path=/tmp/serial-socket,server,nowait -device virtserialport,bus=virtio-serial0.0,nr=1,chardev=charchannel0,id=channel0,name=com.redhat.rhevm.vdsm -chardev socket,path=/tmp/foo,server,nowait,id=foo -device virtconsole,chardev=foo,id=console0 -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x9 -vnc :10 -k en-us -boot c   -global  PIIX4_PM.disable_s3=0 -global PIIX4_PM.disable_s4=0  -device virtio-rng-pci,bus=pci.0,addr=0xa,id=rng0

3. #cat /dev/hwrng (inside guest)

4. Do s3 and s4 for many times. 

Result: Guest can do S3 and S4 correctly and resume back.
(For rhel6.3, there's call trace log in dmesg after resume, i remember it was an old 6.3 issue. And for rhel6.4, there's no such error or call trace in dmesg.)

Hi, Amit
Is there something wrong with my steps? Because actually I can not reproduce the issue for both old and latest rhel6 kernel. Or the 'guest moved used index from xxx to xxx' error is just in theory?


Thanks,
Qunfang

To test, first transfer some data from host->guest (keep 'cat /dev/hwrng' going on).  After some data is read by the guest (i.e. when some data is shown in the terminal), put the guest in sleep states.  Starting a new cat process after resume (or letting the old one continue) should cause the 'guest moved ...' message.

If s3/s4 works fine, we can go ahead and mark this verified.  I don't exactly remember the errors that could happen before the fix now, but if

1. cat /dev/hwrng
2. s3/s4
3. resume
4. data is returned from /dev/hwrng

and

1. cat /dev/hwrng
2. s3/s4
3. resume
4. ^C

both work fine, then let's mark this verified.

OK, thanks for the confirmation. Verify it then as guest S3/resume and S4/resume  work fine after a repeat loop of implementation.

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.

http://rhn.redhat.com/errata/RHSA-2013-0496.html