1. 12 May, 2016 3 commits
    • Gavin Shan's avatar
      powerpc/eeh: Restore initial state in eeh_pe_reset_and_recover() · 5a0cdbfd
      Gavin Shan authored
      The function eeh_pe_reset_and_recover() is used to recover EEH
      error when the passthrou device are transferred to guest and
      backwards. The content in the device's config space will be lost
      on PE reset issued in the middle of the recovery. The function
      saves/restores it before/after the reset. However, config access
      to some adapters like Broadcom BCM5719 at this point will causes
      fenced PHB. The config space is always blocked and we save 0xFF's
      that are restored at late point. The memory BARs are totally
      corrupted, causing another EEH error upon access to one of the
      memory BARs.
      
      This restores the config space on those adapters like BCM5719
      from the content saved to the EEH device when it's populated,
      to resolve above issue.
      
      Fixes: 5cfb20b9 ("powerpc/eeh: Emulate EEH recovery for VFIO devices")
      Cc: stable@vger.kernel.org #v3.18+
      Signed-off-by: default avatarGavin Shan <gwshan@linux.vnet.ibm.com>
      Reviewed-by: default avatarRussell Currey <ruscur@russell.cc>
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      5a0cdbfd
    • Gavin Shan's avatar
      powerpc/eeh: Don't report error in eeh_pe_reset_and_recover() · affeb0f2
      Gavin Shan authored
      The function eeh_pe_reset_and_recover() is used to recover EEH
      error when the passthrough device are transferred to guest and
      backwards, meaning the device's driver is vfio-pci or none.
      When the driver is vfio-pci that provides error_detected() error
      handler only, the handler simply stops the guest and it's not
      expected behaviour. On the other hand, no error handlers will
      be called if we don't have a bound driver.
      
      This ignores the error handler in eeh_pe_reset_and_recover()
      that reports the error to device driver to avoid the exceptional
      behaviour.
      
      Fixes: 5cfb20b9 ("powerpc/eeh: Emulate EEH recovery for VFIO devices")
      Cc: stable@vger.kernel.org #v3.18+
      Signed-off-by: default avatarGavin Shan <gwshan@linux.vnet.ibm.com>
      Reviewed-by: default avatarRussell Currey <ruscur@russell.cc>
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      affeb0f2
    • Michael Ellerman's avatar
      Revert "powerpc/powernv: Exclude root bus in pnv_pci_reset_secondary_bus()" · 848912e5
      Michael Ellerman authored
      This reverts commit c8ceacc2.
      
      Gavin says: I missed the fact that it affects the PCI passthrou path as
      reported by Alexey: When passing GPU (0003:01:00.0) which seats behind
      the root port, the reset request is routed to skiboot in original code.
      In skiboot, the link bouncing events are masked during the reset. So we
      don't see EEH (freeze all) error even link bouncing happens. With the
      changes included, the reset is done by kernel and the link bouncing
      events aren't masked by altering content of PHB3 (or P7IOC) specific
      hardware registers which are invisible to kernel (skiboot hides the
      hardware specific). It means the link bouncing is seen by the root port
      and it causes a EEH (freeze all) error. The PCI passthrough on GPU
      device cannot work.
      Requested-by: default avatarAlexey Kardashevskiy <aik@ozlabs.ru>
      Requested-by: default avatarGavin Shan <gwshan@linux.vnet.ibm.com>
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      848912e5
  2. 11 May, 2016 37 commits