[PATCH V10 11/12] powerpc/eeh: Don't block PCI config on resetting VF PE

[Wei Yang]

On Fri, Oct 30, 2015 at 04:42:07PM +1100, Alexey Kardashevskiy wrote:
>On 10/26/2015 02:16 PM, Wei Yang wrote:
>>From: Gavin Shan <gwshan at linux.vnet.ibm.com>
>>
>>When passing through SRIOV VF from host to guest via VFIO PCI
>>infrastructure, the VF is resetted by EEH specific backend
>>(pcibios_set_pcie_reset_state()). We can't block the PCI config,
>>otherwise, the reset (FLR or AF FLR), to be completed by PCI
>>config access to the VF, can't be done. Then the VF can't be
>>put into initial state when passing it to the guest and returning
>>back to the host.
>>
>>The patch just doesn't block the VF's PCI config space when doing
>>the reset. It fixes EEH error caused by DMA traffic to bogus DMA
>>address on restarting guest after killing the QEMU process, which
>>includes Mellanox VF passed through from host.
>
>The patch as it is makes sense as a bugfix for our internal tree where the
>EEH VF feature was present at the time when this patch was posted but in this
>patchset is makes more sense to merge it into:
>
>[PATCH V10 08/12] powerpc/powernv: Support EEH reset for VF PE
>
>as it is quite weird within one patchset to introduce a problem  and then fix
>it in a following patch.
>

Sure, got it.

>
>>Reported-by: Alexey Kardashevskiy <aik at ozlabs.ru>
>>Signed-off-by: Gavin Shan <gwshan at linux.vnet.ibm.com>
>>Tested-by: Alexey Kardashevskiy <aik at ozlabs.ru>
>>Signed-off-by: Alexey Kardashevskiy <aik at ozlabs.ru>
>
>Remove "sob: aik at ..." please.
>
>
>>---
>>  arch/powerpc/kernel/eeh.c | 9 ++++++---
>>  1 file changed, 6 insertions(+), 3 deletions(-)
>>
>>diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
>>index 28e4d73..e1846f5 100644
>>--- a/arch/powerpc/kernel/eeh.c
>>+++ b/arch/powerpc/kernel/eeh.c
>>@@ -745,7 +745,8 @@ int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state stat
>>  	case pcie_deassert_reset:
>>  		eeh_ops->reset(pe, EEH_RESET_DEACTIVATE);
>>  		eeh_unfreeze_pe(pe, false);
>>-		eeh_pe_state_clear(pe, EEH_PE_CFG_BLOCKED);
>>+		if (!(pe->type & EEH_PE_VF))
>>+			eeh_pe_state_clear(pe, EEH_PE_CFG_BLOCKED);
>>  		eeh_pe_dev_traverse(pe, eeh_restore_dev_state, dev);
>>  		eeh_pe_state_clear(pe, EEH_PE_ISOLATED);
>>  		break;
>>@@ -753,14 +754,16 @@ int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state stat
>>  		eeh_pe_state_mark(pe, EEH_PE_ISOLATED);
>>  		eeh_ops->set_option(pe, EEH_OPT_FREEZE_PE);
>>  		eeh_pe_dev_traverse(pe, eeh_disable_and_save_dev_state, dev);
>>-		eeh_pe_state_mark(pe, EEH_PE_CFG_BLOCKED);
>>+		if (!(pe->type & EEH_PE_VF))
>>+			eeh_pe_state_mark(pe, EEH_PE_CFG_BLOCKED);
>>  		eeh_ops->reset(pe, EEH_RESET_HOT);
>>  		break;
>>  	case pcie_warm_reset:
>>  		eeh_pe_state_mark(pe, EEH_PE_ISOLATED);
>>  		eeh_ops->set_option(pe, EEH_OPT_FREEZE_PE);
>>  		eeh_pe_dev_traverse(pe, eeh_disable_and_save_dev_state, dev);
>>-		eeh_pe_state_mark(pe, EEH_PE_CFG_BLOCKED);
>>+		if (!(pe->type & EEH_PE_VF))
>>+			eeh_pe_state_mark(pe, EEH_PE_CFG_BLOCKED);
>>  		eeh_ops->reset(pe, EEH_RESET_FUNDAMENTAL);
>>  		break;
>>  	default:
>>
>
>
>-- 
>Alexey

-- 
Richard Yang
Help you, Help me