5.4-stable review patch. If anyone has any objections, please let me know.
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From: Narayana Murty N nnmlinux@linux.ibm.com
commit 11b93559000c686ad7e5ab0547e76f21cc143844 upstream.
The PE Reset State "0" returned by RTAS calls "ibm_read_slot_reset_[state|state2]" indicates that the reset is deactivated and the PE is in a state where MMIO and DMA are allowed. However, the current implementation of "pseries_eeh_get_state()" does not reflect this, causing drivers to incorrectly assume that MMIO and DMA operations cannot be resumed.
The userspace drivers as a part of EEH recovery using VFIO ioctls fail to detect when the recovery process is complete. The VFIO_EEH_PE_GET_STATE ioctl does not report the expected EEH_PE_STATE_NORMAL state, preventing userspace drivers from functioning properly on pseries systems.
The patch addresses this issue by updating 'pseries_eeh_get_state()' to include "EEH_STATE_MMIO_ENABLED" and "EEH_STATE_DMA_ENABLED" in the result mask for PE Reset State "0". This ensures correct state reporting to the callers, aligning the behavior with the PAPR specification and fixing the bug in EEH recovery for VFIO user workflows.
Fixes: 00ba05a12b3c ("powerpc/pseries: Cleanup on pseries_eeh_get_state()") Cc: stable@vger.kernel.org Reviewed-by: Ritesh Harjani (IBM) ritesh.list@gmail.com Signed-off-by: Narayana Murty N nnmlinux@linux.ibm.com Link: https://lore.kernel.org/stable/20241212075044.10563-1-nnmlinux%40linux.ibm.c... Signed-off-by: Madhavan Srinivasan maddy@linux.ibm.com Link: https://patch.msgid.link/20250116103954.17324-1-nnmlinux@linux.ibm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/powerpc/platforms/pseries/eeh_pseries.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
--- a/arch/powerpc/platforms/pseries/eeh_pseries.c +++ b/arch/powerpc/platforms/pseries/eeh_pseries.c @@ -472,8 +472,10 @@ static int pseries_eeh_get_state(struct
switch(rets[0]) { case 0: - result = EEH_STATE_MMIO_ACTIVE | - EEH_STATE_DMA_ACTIVE; + result = EEH_STATE_MMIO_ACTIVE | + EEH_STATE_DMA_ACTIVE | + EEH_STATE_MMIO_ENABLED | + EEH_STATE_DMA_ENABLED; break; case 1: result = EEH_STATE_RESET_ACTIVE |