1. 10 Nov, 2015 11 commits
  2. 05 Nov, 2015 1 commit
    • Kai Huang's avatar
      KVM: VMX: Fix commit which broke PML · a3eaa864
      Kai Huang authored
      I found PML was broken since below commit:
      
      	commit feda805f
      	Author: Xiao Guangrong <guangrong.xiao@linux.intel.com>
      	Date:   Wed Sep 9 14:05:55 2015 +0800
      
      	KVM: VMX: unify SECONDARY_VM_EXEC_CONTROL update
      
      	Unify the update in vmx_cpuid_update()
      Signed-off-by: default avatarXiao Guangrong <guangrong.xiao@linux.intel.com>
      	[Rewrite to use vmcs_set_secondary_exec_control. - Paolo]
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      
      The reason is in above commit vmx_cpuid_update calls vmx_secondary_exec_control,
      in which currently SECONDARY_EXEC_ENABLE_PML bit is cleared unconditionally (as
      PML is enabled in creating vcpu). Therefore if vcpu_cpuid_update is called after
      vcpu is created, PML will be disabled unexpectedly while log-dirty code still
      thinks PML is used.
      
      Fix this by clearing SECONDARY_EXEC_ENABLE_PML in vmx_secondary_exec_control
      only when PML is not supported or not enabled (!enable_pml). This is more
      reasonable as PML is currently either always enabled or disabled. With this
      explicit updating SECONDARY_EXEC_ENABLE_PML in vmx_enable{disable}_pml is not
      needed so also rename vmx_enable{disable}_pml to vmx_create{destroy}_pml_buffer.
      
      Fixes: feda805fSigned-off-by: default avatarKai Huang <kai.huang@linux.intel.com>
      [While at it, change a wrong ASSERT to an "if".  The condition can happen
       if creating the VCPU fails with ENOMEM. - Paolo]
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      a3eaa864
  3. 04 Nov, 2015 16 commits
  4. 02 Nov, 2015 2 commits
  5. 29 Oct, 2015 3 commits
    • Christian Borntraeger's avatar
      KVM: s390: use simple switch statement as multiplexer · 46b708ea
      Christian Borntraeger authored
      We currently do some magic shifting (by exploiting that exit codes
      are always a multiple of 4) and a table lookup to jump into the
      exit handlers. This causes some calculations and checks, just to
      do an potentially expensive function call.
      
      Changing that to a switch statement gives the compiler the chance
      to inline and dynamically decide between jump tables or inline
      compare and branches. In addition it makes the code more readable.
      
      bloat-o-meter gives me a small reduction in code size:
      
      add/remove: 0/7 grow/shrink: 1/1 up/down: 986/-1334 (-348)
      function                                     old     new   delta
      kvm_handle_sie_intercept                      72    1058    +986
      handle_prog                                  704     696      -8
      handle_noop                                   54       -     -54
      handle_partial_execution                      60       -     -60
      intercept_funcs                              120       -    -120
      handle_instruction                           198       -    -198
      handle_validity                              210       -    -210
      handle_stop                                  316       -    -316
      handle_external_interrupt                    368       -    -368
      
      Right now my gcc does conditional branches instead of jump tables.
      The inlining seems to give us enough cycles as some micro-benchmarking
      shows minimal improvements, but still in noise.
      Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
      Reviewed-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
      46b708ea
    • Christian Borntraeger's avatar
      KVM: s390: drop useless newline in debugging data · 58c383c6
      Christian Borntraeger authored
      the s390 debug feature does not need newlines. In fact it will
      result in empty lines. Get rid of 4 leftovers.
      Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
      Acked-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
      58c383c6
    • David Hildenbrand's avatar
      KVM: s390: SCA must not cross page boundaries · c5c2c393
      David Hildenbrand authored
      We seemed to have missed a few corner cases in commit f6c137ff
      ("KVM: s390: randomize sca address").
      
      The SCA has a maximum size of 2112 bytes. By setting the sca_offset to
      some unlucky numbers, we exceed the page.
      
      0x7c0 (1984) -> Fits exactly
      0x7d0 (2000) -> 16 bytes out
      0x7e0 (2016) -> 32 bytes out
      0x7f0 (2032) -> 48 bytes out
      
      One VCPU entry is 32 bytes long.
      
      For the last two cases, we actually write data to the other page.
      1. The address of the VCPU.
      2. Injection/delivery/clearing of SIGP externall calls via SIGP IF.
      
      Especially the 2. happens regularly. So this could produce two problems:
      1. The guest losing/getting external calls.
      2. Random memory overwrites in the host.
      
      So this problem happens on every 127 + 128 created VM with 64 VCPUs.
      
      Cc: stable@vger.kernel.org # v3.15+
      Acked-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
      Signed-off-by: default avatarDavid Hildenbrand <dahi@linux.vnet.ibm.com>
      Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
      c5c2c393
  6. 22 Oct, 2015 7 commits