Re: [PATCH v5 1/3] PCI/IOV: Mark VFs as not implementing PCI_COMMAND_MEMORY

[Bjorn Helgaas <helgaas@kernel.org>]

On Thu, Sep 10, 2020 at 10:59:55AM -0400, Matthew Rosato wrote:
> For VFs, the Memory Space Enable bit in the Command Register is
> hard-wired to 0.
> 
> Add a new bit to signify devices where the Command Register Memory
> Space Enable bit does not control the device's response to MMIO
> accesses.
> 
> Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>

Acked-by: Bjorn Helgaas <bhelgaas@google.com>

> ---
>  drivers/pci/iov.c   | 1 +
>  include/linux/pci.h | 1 +
>  2 files changed, 2 insertions(+)
> 
> diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
> index b37e08c..4afd4ee 100644
> --- a/drivers/pci/iov.c
> +++ b/drivers/pci/iov.c
> @@ -180,6 +180,7 @@ int pci_iov_add_virtfn(struct pci_dev *dev, int id)
>  	virtfn->device = iov->vf_device;
>  	virtfn->is_virtfn = 1;
>  	virtfn->physfn = pci_dev_get(dev);
> +	virtfn->no_command_memory = 1;
>  
>  	if (id == 0)
>  		pci_read_vf_config_common(virtfn);
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 8355306..3ff72312 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -445,6 +445,7 @@ struct pci_dev {
>  	unsigned int	is_probed:1;		/* Device probing in progress */
>  	unsigned int	link_active_reporting:1;/* Device capable of reporting link active */
>  	unsigned int	no_vf_scan:1;		/* Don't scan for VFs after IOV enablement */
> +	unsigned int	no_command_memory:1;	/* No PCI_COMMAND_MEMORY */
>  	pci_dev_flags_t dev_flags;
>  	atomic_t	enable_cnt;	/* pci_enable_device has been called */
>  
> -- 
> 1.8.3.1
>