Re: [PATCH] virtio-pci: alloc only resources actually used.

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



  Hi,

> > +static struct resource *request_capability(struct pci_dev *dev, int off,
> > +					   const char *name)
> > +{
> > +	u8 bar;
> > +	u32 offset, length;
> > +
> > +	pci_read_config_byte(dev, off + offsetof(struct virtio_pci_cap,
> > +						 bar),
> > +			     &bar);
> > +	pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, offset),
> > +			     &offset);
> > +	pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, length),
> > +			      &length);
> > +
> > +	return request_mem_region(pci_resource_start(dev, bar) + offset,
> > +				  length, name);
> > +}
> > +
> 
> For device config, this might request too much. The spec says:
> 	The drivers SHOULD only map part of configuration structure large enough
> 	for device operation.

We don't map it here though.  We just reserve what belongs to virtio
according to the capabilities.

> I think you should limit this to PAGE_SIZE like we do for map_capability.

notify is much larger than PAGE_SIZE.

> >  	err = -EINVAL;
> >  	vp_dev->common = map_capability(pci_dev, common,
> >  					sizeof(struct virtio_pci_common_cfg), 4,
> 
> map_capability has a bunch of checks in place to validate the capability
> structure. With request_capability called earlier, they are now done too
> late.

Hmm, lets move the checks to find_capability then?

cheers,
  Gerd


_______________________________________________
Virtualization mailing list
Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
https://lists.linuxfoundation.org/mailman/listinfo/virtualization



[Index of Archives]     [KVM Development]     [Libvirt Development]     [Libvirt Users]     [CentOS Virtualization]     [Netdev]     [Ethernet Bridging]     [Linux Wireless]     [Kernel Newbies]     [Security]     [Linux for Hams]     [Netfilter]     [Bugtraq]     [Yosemite Forum]     [MIPS Linux]     [ARM Linux]     [Linux RAID]     [Linux Admin]     [Samba]

  Powered by Linux