Re: [Qemu-devel] [PATCH 2/2] pcie_aer: clear cmask for Advanced Error Interrupt Message Number

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

Some minor nits below. If you dont get to it I will tweak this patch
when I apply it early next week.

On Thu, Aug 30, 2012 at 01:51:15PM -0400, Jason Baron wrote:
> The Advanced Error Interrupt Message Number (bits 31:27 of the Root
> Error Status Register) is updated when the number of msi messages assigned to a
> device changes. Migration of windows 7 on q35 chipset failed because the check
> in get_pci_config_device() fails due to wmask being set on these bits.

I think you actually mean 'not being set on these bits'?

> Its valid
> to update these bits and we must restore this state across migration.
> 
> Signed-off-by: Jason Baron <jbaron@redhat.com>
> ---
>  hw/pcie_aer.c |    6 ++++++
>  1 files changed, 6 insertions(+), 0 deletions(-)
> 
> diff --git a/hw/pcie_aer.c b/hw/pcie_aer.c
> index 3b6981c..6edcd79 100644
> --- a/hw/pcie_aer.c
> +++ b/hw/pcie_aer.c
> @@ -738,6 +738,12 @@ void pcie_aer_root_init(PCIDevice *dev)
>                   PCI_ERR_ROOT_CMD_EN_MASK);
>      pci_set_long(dev->w1cmask + pos + PCI_ERR_ROOT_STATUS,
>                   PCI_ERR_ROOT_STATUS_REPORT_MASK);
> +    /* Bits 31:27 - Advanced Error Interrupt Message Number

This line is better moved to near definition of PCI_ERR_ROOT_IRQ.
Then here we can say 'PCI_ERR_ROOT_IRQ is RO but devices
change it using a device-specific method.'

> +     * These bits are updated when the number of MSI messages changes.
> +     * By clearing the cmask, pcie devices can be migrated.
> +     */
> +    pci_set_long(dev->cmask + pos + PCI_ERR_ROOT_STATUS,
> +                 (1 << PCI_ERR_ROOT_IRQ_SHIFT) - 1);

~PCI_ERR_ROOT_IRQ would be clearer I think.

>  }



>  
>  void pcie_aer_root_reset(PCIDevice *dev)
> -- 
> 1.7.1