1. 26 Mar, 2009 1 commit
    • Christian Borntraeger's avatar
      [S390] Fix hypervisor detection for KVM · 92e6ecf3
      Christian Borntraeger authored
      
      
      Currently we use the cpuid (via STIDP instruction) to recognize LPAR,
      z/VM and KVM.
      The architecture states, that bit 0-7 of STIDP returns all zero, and
      if STIDP is executed in a virtual machine, the VM operating system
      will replace bits 0-7 with FF.
      
      KVM should not use FE to distinguish z/VM from KVM for interested
      guests. The proper way to detect the hypervisor is the STSI (Store
      System Information) instruction, which return information about the
      hypervisors via function code 3, selector1=2, selector2=2.
      
      This patch changes the detection routine of Linux to use STSI instead
      of STIDP. This detection is earlier than bootmem, we have to use a
      static buffer. Since STSI expects a 4kb block (4kb aligned) this
      patch also changes the init.data alignment for s390. As this section
      will be freed during boot, this should be no problem.
      
      Patch is tested with LPAR, z/VM, KVM on LPAR, and KVM under z/VM.
      Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
      Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
      92e6ecf3
  2. 14 Jul, 2008 4 commits
  3. 30 Apr, 2008 2 commits
  4. 27 Apr, 2008 1 commit
  5. 16 Apr, 2008 1 commit
  6. 05 Mar, 2008 1 commit
  7. 26 Jan, 2008 2 commits
    • Heiko Carstens's avatar
      [S390] Get rid of additional_cpus kernel parameter. · 48483b32
      Heiko Carstens authored
      
      
      It caused only a lot of confusion. From now on cpu hotplug of up to
      NR_CPUS will work by default. If somebody wants to limit that then
      the possible_cpus parameter can be used.
      Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
      Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
      48483b32
    • Heiko Carstens's avatar
      [S390] Standby cpu activation/deactivation. · 08d07968
      Heiko Carstens authored
      
      
      Add a new interface so that cpus can be put into standby state and
      configured state.
      Only offline cpus can be put into standby state or configured state.
      For that the new percpu sysfs attribute "configure" must be used.
      To put a cpu in standby state a "0" must be written to the attribute.
      In order to switch it into configured state a "1" must be written to
      the attribute.
      Only cpus in configured state can be brought online.
      In addition this patch introduces a static mapping of physical to
      logical cpus. As a result only the sysfs directories of present cpus
      will be created. To scan for new cpus the new sysfs attribute "rescan"
      must be used.
      Writing to /sys/devices/system/cpu/rescan will trigger a rescan of
      cpus and will create directories for new cpus.
      
      On IPL only configured cpus will be used. And on reboot/shutdown all
      cpus will remain in their current state (configured/standby).
      Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
      Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
      08d07968
  8. 20 Nov, 2007 1 commit
  9. 05 Nov, 2007 1 commit
  10. 10 Jul, 2007 2 commits
  11. 27 Apr, 2007 1 commit
  12. 19 Mar, 2007 1 commit
  13. 21 Feb, 2007 3 commits
  14. 05 Feb, 2007 2 commits