kernel/linux
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ synced 2026-11-10 20:48:12 +00:00
Code Issues Releases Packages Activity

KVM: s390: bugfix for kvm/master (4.2)

Browse source 
Here is a bugfix for a regression that was introduced after 4.1
 with the commit commit 785dbef407 ("KVM: s390: optimize round
 trip time in request handling"). After lots of cpu hotplugs in the
 guest (online/offline) sometimes a guest CPU did loop within host
 KVM code. Reason was that PROG_REQUEST was set in the sie control
 block, but no request was pending. This made commit 785dbef407
 the suspect and changing that area to always reset PROG_REQUEST
 did indeed fix the problem.
 
 Special thanks to David Hildenbrand, who helped understanding the
 exact sequence that led to the problem.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.14 (GNU/Linux)
 
 iQIcBAABAgAGBQJVugfQAAoJEBF7vIC1phx8aYIP/1Axd7er7Z3M6ls33cYznVKz
 kAF1gsOemBkIHX7E/tpI8ReYBc+jHrAj+QlYF6loGVnIbb2TpA3PQsswYk3hfbNg
 rpmR7OCezwXCWKUOSy5QPtop7Be3Z4+mitAYjwz8GR4Bqw54IoZs8yExgFeDYVmK
 eRTQjNOjCFQ5ba9nNEf8uBGal4ND9nx46JMIZy7tUwN9Jl0RLr8PaBN89JeS3vYg
 olIxrSwZUXTX0NEr04o9LZ+68aOVhMpzhCFbaACvvUg9YCjyMFIuSDtYLnh6+yKN
 EztHjmlNA54TuAW/XVb0Kayiq0PU32Z9GwD4nCluacsxbLaNB2rC43PYjZPqlXn/
 TwYTTSDrct/RdLtwNOaI/V89sNgTmvwAU8Qt1IFHd3lu9XZS0EJAkU30mUEOh1Mv
 skP9wLmjdjNOZfdyVLu1RBu70mEfuUGKT2QKRmgW5RMMfhXSLaSyUKf/npiXiv/m
 5FfmhGBt+qlusTuCVcvuyqci1GSjaSZUIXcIy95gpU5OaXvxCWQiE3dNOXRAlBmc
 sdQ3WLVXd1AileCSkCvGxzzqA7If3M715ac1+IpnkM5Mmv38cCfSZDEoFGAnaEvi
 m+ISQ1nRVmdRFbuKTIOdxJS06PZ6ysF2IDeL4b6X1L055Zf80gSe2iXxqOcfJ27e
 X8InBSuF1G9VqihjkbQm
 =eHXj
 -----END PGP SIGNATURE-----

Merge tag 'kvm-s390-master-20150730' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into kvm-master

KVM: s390: bugfix for kvm/master (4.2)

Here is a bugfix for a regression that was introduced after 4.1
with the commit commit 785dbef407 ("KVM: s390: optimize round
trip time in request handling"). After lots of cpu hotplugs in the
guest (online/offline) sometimes a guest CPU did loop within host
KVM code. Reason was that PROG_REQUEST was set in the sie control
block, but no request was pending. This made commit 785dbef407
the suspect and changing that area to always reset PROG_REQUEST
did indeed fix the problem.

Special thanks to David Hildenbrand, who helped understanding the
exact sequence that led to the problem.
This commit is contained in:
Paolo Bonzini 2015-07-30 13:30:03 +02:00
commit 7307f70c6d
1 changed files with 2 additions and 2 deletions
Download patch file Download diff file Expand all files Collapse all files