1. 02 Jul, 2019 23 commits
  2. 01 Jul, 2019 15 commits
  3. 25 Jun, 2019 1 commit
    • Nicholas Piggin's avatar
      powerpc/64s/exception: Fix machine check early corrupting AMR · e13e7cd4
      Nicholas Piggin authored
      The early machine check runs in real mode, so locking is unnecessary.
      Worse, the windup does not restore AMR, so this can result in a false
      KUAP fault after a recoverable machine check hits inside a user copy
      operation.
      
      Fix this similarly to HMI by just avoiding the kuap lock in the
      early machine check handler (it will be set by the late handler that
      runs in virtual mode if that runs). If the virtual mode handler is
      reached, it will lock and restore the AMR.
      
      Fixes: 890274c2 ("powerpc/64s: Implement KUAP for Radix MMU")
      Cc: Russell Currey <ruscur@russell.cc>
      Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      e13e7cd4
  4. 20 Jun, 2019 1 commit
    • Suraj Jitindar Singh's avatar
      KVM: PPC: Book3S HV: Clear pending decrementer exceptions on nested guest entry · 3c25ab35
      Suraj Jitindar Singh authored
      If we enter an L1 guest with a pending decrementer exception then this
      is cleared on guest exit if the guest has writtien a positive value
      into the decrementer (indicating that it handled the decrementer
      exception) since there is no other way to detect that the guest has
      handled the pending exception and that it should be dequeued. In the
      event that the L1 guest tries to run a nested (L2) guest immediately
      after this and the L2 guest decrementer is negative (which is loaded
      by L1 before making the H_ENTER_NESTED hcall), then the pending
      decrementer exception isn't cleared and the L2 entry is blocked since
      L1 has a pending exception, even though L1 may have already handled
      the exception and written a positive value for it's decrementer. This
      results in a loop of L1 trying to enter the L2 guest and L0 blocking
      the entry since L1 has an interrupt pending with the outcome being
      that L2 never gets to run and hangs.
      
      Fix this by clearing any pending decrementer exceptions when L1 makes
      the H_ENTER_NESTED hcall since it won't do this if it's decrementer
      has gone negative, and anyway it's decrementer has been communicated
      to L0 in the hdec_expires field and L0 will return control to L1 when
      this goes negative by delivering an H_DECREMENTER exception.
      
      Fixes: 95a6432c ("KVM: PPC: Book3S HV: Streamlined guest entry/exit path on P9 for radix guests")
      Cc: stable@vger.kernel.org # v4.20+
      Signed-off-by: default avatarSuraj Jitindar Singh <sjitindarsingh@gmail.com>
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      3c25ab35