• Christian Borntraeger's avatar
    s390/kvm: dont announce RRBM support · 115f5063
    Christian Borntraeger authored
    commit 87cac8f8 upstream.
    
    Newer kernels (linux-next with the transparent huge page patches)
    use rrbm if the feature is announced via feature bit 66.
    RRBM will cause intercepts, so KVM does not handle it right now,
    causing an illegal instruction in the guest.
    The  easy solution is to disable the feature bit for the guest.
    
    This fixes bugs like:
    Kernel BUG at 0000000000124c2a [verbose debug info unavailable]
    illegal operation: 0001 [#1] SMP
    Modules linked in: virtio_balloon virtio_net ipv6 autofs4
    CPU: 0 Not tainted 3.5.4 #1
    Process fmempig (pid: 659, task: 000000007b712fd0, ksp: 000000007bed3670)
    Krnl PSW : 0704d00180000000 0000000000124c2a (pmdp_clear_flush_young+0x5e/0x80)
         R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:1 PM:0 EA:3
         00000000003cc000 0000000000000004 0000000000000000 0000000079800000
         0000000000040000 0000000000000000 000000007bed3918 000000007cf40000
         0000000000000001 000003fff7f00000 000003d281a94000 000000007bed383c
         000000007bed3918 00000000005ecbf8 00000000002314a6 000000007bed36e0
     Krnl Code:>0000000000124c2a: b9810025          ogr     %r2,%r5
               0000000000124c2e: 41343000           la      %r3,0(%r4,%r3)
               0000000000124c32: a716fffa           brct    %r1,124c26
               0000000000124c36: b9010022           lngr    %r2,%r2
               0000000000124c3a: e3d0f0800004       lg      %r13,128(%r15)
               0000000000124c40: eb22003f000c       srlg    %r2,%r2,63
    [ 2150.713198] Call Trace:
    [ 2150.713223] ([<00000000002312c4>] page_referenced_one+0x6c/0x27c)
    [ 2150.713749]  [<0000000000233812>] page_referenced+0x32a/0x410
    [...]
    
    CC: Alex Graf <agraf@suse.de>
    Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
    Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
    Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
    Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
    Cc: Qiang Huang <h.huangqiang@huawei.com>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    115f5063
kvm-s390.c 23.3 KB