RE: [PATCH] vfio/pci: Some buggy virtual functions incorrectly report 1 for intx.

From: Eads, Gage
Date: Wed Sep 19 2018 - 18:26:20 EST

> This looks good and also addresses Alan's concern that don't silently hide under
> the rug for all devices. We'll also queue it for testing just to confirm and keep
> you posted.
> Reviewed-by: Ashok Raj <ashok.raj@xxxxxxxxx>

Hi Alex,

I've confirmed that the patch works as intended for the 8086:270c device, and negative tested the warning by commenting out the device's entry in known_bogus_vf_intx_pin.

For what it's worth, my positive test case - launching a QEMU VM with a VFIO-owned 0x270c device - did not trigger the warning. This is because the change to vfio_pci_config.c caused QEMU to read a PCI_INTERRUPT_PIN value of 0, and so didn't execute a codepath that calls vfio_pci_get_irq_count(). Instead, I used a simple C program that calls the VFIO_DEVICE_GET_IRQ_INFO ioctl for negative testing.

Also, there's one typo in the comment: 'quite' -> 'quiet'

Tested-by: Gage Eads <gage.eads@xxxxxxxxx>