1. 17 Oct, 2013 6 commits
    • Paul Mackerras's avatar
      KVM: PPC: Book3S HV: Restructure kvmppc_hv_entry to be a subroutine · 218309b7
      Paul Mackerras authored
      We have two paths into and out of the low-level guest entry and exit
      code: from a vcpu task via kvmppc_hv_entry_trampoline, and from the
      system reset vector for an offline secondary thread on POWER7 via
      kvm_start_guest.  Currently both just branch to kvmppc_hv_entry to
      enter the guest, and on guest exit, we test the vcpu physical thread
      ID to detect which way we came in and thus whether we should return
      to the vcpu task or go back to nap mode.
      
      In order to make the code flow clearer, and to keep the code relating
      to each flow together, this turns kvmppc_hv_entry into a subroutine
      that follows the normal conventions for call and return.  This means
      that kvmppc_hv_entry_trampoline() and kvmppc_hv_entry() now establish
      normal stack frames, and we use the normal stack slots for saving
      return addresses rather than local_paca->kvm_hstate.vmhandler.  Apart
      from that this is mostly moving code around unchanged.
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      218309b7
    • Paul Mackerras's avatar
      KVM: PPC: Book3S HV: Implement H_CONFER · 42d7604d
      Paul Mackerras authored
      The H_CONFER hypercall is used when a guest vcpu is spinning on a lock
      held by another vcpu which has been preempted, and the spinning vcpu
      wishes to give its timeslice to the lock holder.  We implement this
      in the straightforward way using kvm_vcpu_yield_to().
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      42d7604d
    • Paul Mackerras's avatar
      KVM: PPC: Book3S: Add GET/SET_ONE_REG interface for VRSAVE · c0867fd5
      Paul Mackerras authored
      The VRSAVE register value for a vcpu is accessible through the
      GET/SET_SREGS interface for Book E processors, but not for Book 3S
      processors.  In order to make this accessible for Book 3S processors,
      this adds a new register identifier for GET/SET_ONE_REG, and adds
      the code to implement it.
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      c0867fd5
    • Paul Mackerras's avatar
      KVM: PPC: Book3S HV: Implement timebase offset for guests · 93b0f4dc
      Paul Mackerras authored
      This allows guests to have a different timebase origin from the host.
      This is needed for migration, where a guest can migrate from one host
      to another and the two hosts might have a different timebase origin.
      However, the timebase seen by the guest must not go backwards, and
      should go forwards only by a small amount corresponding to the time
      taken for the migration.
      
      Therefore this provides a new per-vcpu value accessed via the one_reg
      interface using the new KVM_REG_PPC_TB_OFFSET identifier.  This value
      defaults to 0 and is not modified by KVM.  On entering the guest, this
      value is added onto the timebase, and on exiting the guest, it is
      subtracted from the timebase.
      
      This is only supported for recent POWER hardware which has the TBU40
      (timebase upper 40 bits) register.  Writing to the TBU40 register only
      alters the upper 40 bits of the timebase, leaving the lower 24 bits
      unchanged.  This provides a way to modify the timebase for guest
      migration without disturbing the synchronization of the timebase
      registers across CPU cores.  The kernel rounds up the value given
      to a multiple of 2^24.
      
      Timebase values stored in KVM structures (struct kvm_vcpu, struct
      kvmppc_vcore, etc.) are stored as host timebase values.  The timebase
      values in the dispatch trace log need to be guest timebase values,
      however, since that is read directly by the guest.  This moves the
      setting of vcpu->arch.dec_expires on guest exit to a point after we
      have restored the host timebase so that vcpu->arch.dec_expires is a
      host timebase value.
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      93b0f4dc
    • Paul Mackerras's avatar
      KVM: PPC: Book3S HV: Save/restore SIAR and SDAR along with other PMU registers · 14941789
      Paul Mackerras authored
      Currently we are not saving and restoring the SIAR and SDAR registers in
      the PMU (performance monitor unit) on guest entry and exit.  The result
      is that performance monitoring tools in the guest could get false
      information about where a program was executing and what data it was
      accessing at the time of a performance monitor interrupt.  This fixes
      it by saving and restoring these registers along with the other PMU
      registers on guest entry/exit.
      
      This also provides a way for userspace to access these values for a
      vcpu via the one_reg interface.
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      14941789
    • Michael Neuling's avatar
      KVM: PPC: Book3S HV: Reserve POWER8 space in get/set_one_reg · 3b783474
      Michael Neuling authored
      This reserves space in get/set_one_reg ioctl for the extra guest state
      needed for POWER8.  It doesn't implement these at all, it just reserves
      them so that the ABI is defined now.
      
      A few things to note here:
      
      - This add *a lot* state for transactional memory.  TM suspend mode,
        this is unavoidable, you can't simply roll back all transactions and
        store only the checkpointed state.  I've added this all to
        get/set_one_reg (including GPRs) rather than creating a new ioctl
        which returns a struct kvm_regs like KVM_GET_REGS does.  This means we
        if we need to extract the TM state, we are going to need a bucket load
        of IOCTLs.  Hopefully most of the time this will not be needed as we
        can look at the MSR to see if TM is active and only grab them when
        needed.  If this becomes a bottle neck in future we can add another
        ioctl to grab all this state in one go.
      
      - The TM state is offset by 0x80000000.
      
      - For TM, I've done away with VMX and FP and created a single 64x128 bit
        VSX register space.
      
      - I've left a space of 1 (at 0x9c) since Paulus needs to add a value
        which applies to POWER7 as well.
      Signed-off-by: default avatarMichael Neuling <mikey@neuling.org>
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      3b783474
  2. 16 Oct, 2013 2 commits
  3. 15 Oct, 2013 1 commit
  4. 14 Oct, 2013 7 commits
  5. 13 Oct, 2013 3 commits
  6. 10 Oct, 2013 1 commit
  7. 03 Oct, 2013 8 commits
  8. 02 Oct, 2013 5 commits
  9. 30 Sep, 2013 7 commits