Re: [RFC PATCH 17/19] vfio/pci: Add generic PCI error resume handling

[sashiko-bot@kernel.org]

> Add a resume() handler for vfio-pci-core. It ends the recovery
> transaction and makes the device usable again.
> 
> INTX_DISABLE is taken from the INTx state rather than from the saved word.
> The handler can have masked the line after the word was saved, and
> restoring the saved bit would unmask a line it still believes is masked.
> The replay is what unmasks it.
> 
> Restore the command word saved by error_detected(), unless the device was
> reset, in which case slot_reset() already restored the whole config space
> and the saved value is stale. Then unblock access, un-revoke exported
> DMA-BUFs if the guest still has memory decode enabled, clear IN_PROGRESS
> and replay the INTx state recorded during the event.
> 
> If the command write fails, keep access blocked and publish FAILED.
> IN_PROGRESS is cleared and FAILED set in a single store, so a lock-free
> reader never sees the intermediate state, which would read as a
> successful completion.
> 
> Pay any deferred ROM decode disable first, before the in-progress check.
> A failed transaction has already cleared that flag, and the disable would
> be lost. The helper skips a closed device on its own.
> 
> Until a later patch starts a recovery transaction, only the deferred ROM
> disable runs here. The rest returns early.
> 
> Signed-off-by: Shameer Kolothum <skolothumtho@nvidia.com>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.dev/#/patchset/20260901093217.8539-1-skolothumtho@nvidia.com?part=17