Re: [PATCH] qemu-kvm: device assignment: add 82599 PCIe Cap struct quirk

["Michael S. Tsirkin" <mst@redhat.com>]

On Wed, Sep 28, 2011 at 08:20:33PM -0400, Donald Dutile wrote:
> commit f9c29774d2174df6ffc20becec20928948198914
> changed the PCIe Capability structure version check
> from if > 2 fail, to if ==1, size=x, if ==2, size=y,
> else fail.
> Turns out the 82599's VF has an errata where it's
> PCIe Cap struct version is 0, which now fails device assignment
> due to the else fallout, where before, it would blissfully work.
> 
> Add a quirk if version=0, & intel-82599, set size to version 2 struct.
> 
> Signed-off-by: Donald_Dutile <ddutile@redhat.com>

Makes sense.

Nit: please use PCI_VENDOR_ID_INTEL instead of 0x8086 below.

> ---
>  hw/device-assignment.c |   12 ++++++++++--
>  1 files changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/device-assignment.c b/hw/device-assignment.c
> index 288f80c..ed2a883 100644
> --- a/hw/device-assignment.c
> +++ b/hw/device-assignment.c
> @@ -1261,12 +1261,20 @@ static int assigned_device_pci_cap_init(PCIDevice *pci_dev)
>  
>      if ((pos = pci_find_cap_offset(pci_dev, PCI_CAP_ID_EXP, 0))) {
>          uint8_t version, size;
> -        uint16_t type, devctl, lnkcap, lnksta;
> +        uint16_t type, devctl, lnkcap, lnksta, vendor, device;
>          uint32_t devcap;
>  
> +        vendor = pci_get_word(pci_dev->config + PCI_VENDOR_ID);
> +        device = pci_get_word(pci_dev->config + PCI_DEVICE_ID);
>          version = pci_get_byte(pci_dev->config + pos + PCI_EXP_FLAGS);
>          version &= PCI_EXP_FLAGS_VERS;
> -        if (version == 1) {
> +        if (version == 0 && vendor == 0x8086 && device == 0x10ed) {

I'd also make version == 0 last test in the list
to stress the fact this is a device specific quirk,
but that's a matter of taste ...

> +            /* 
> +             * quirk for Intel 82599 VF with invalid PCIe capability version,
> +             * should really be version 2 (same as PF)
> +             */
> +            size = 0x3c;
> +        } else if (version == 1) {
>              size = 0x14;
>          } else if (version == 2) {
>              /*
> -- 
> 1.7.1