Re: [Qemu-devel] [PATCH 1/1] Add support for PCI Enhanced Allocation "BARs"

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

On Mon, May 11, 2015 at 01:08:05PM -0700, Sean O. Stalley wrote:
> On Mon, May 11, 2015 at 09:26:08PM +0200, Michael S. Tsirkin wrote:
> > On Mon, May 11, 2015 at 11:56:44AM -0700, Sean O. Stalley wrote:
> > > PCI Enhanced Allocation is a new method of allocating MMIO & IO
> > > resources for PCI devices & bridges. It can be used instead
> > > of the traditional PCI method of using BARs.
> > > 
> > > EA entries are hardware-initialized to a fixed address.
> > > Unlike BARs, regions described by EA are cannot be moved.
> > > Because of this, only devices which are perminately connected to
> > > the PCI bus can use EA. A removeable PCI card must not use EA.
> > > 
> > > This patchset enables any existing QEMU PCI model to use EA in leiu of
> > > BARs. It adds EA options to the PCI device paramaters.
> > > 
> > > The Enhanced Allocation ECN is publicly available here:
> > > https://www.pcisig.com/specifications/conventional/ECN_Enhanced_Allocation_23_Oct_2014_Final.pdf
> > > 
> > > Signed-off-by: Sean O. Stalley <sean.stalley@intel.com>
> > 
> > 
> > I will review this, thanks.  Will you also be sending a seabios patch to
> > support these registers?  When you do, please Cc me.
> 
> Thanks Michael,
> 
> I wasn't planning on sending a seabios patch.

Won't this mean that bios might allocate PCI BARs conflicting with
EA entries, causing guest to crash?

> I do have some EDKII/OVMF patches I hope to send out soon. I will Cc you on those.
> 
> -Sean
> 
> > 
> > 
> > > ---
> > >  hw/pci/Makefile.objs      |   2 +-
> > >  hw/pci/pci.c              |  96 ++++++++++++++++------
> > >  hw/pci/pci_ea.c           | 203 ++++++++++++++++++++++++++++++++++++++++++++++
> > >  include/hw/pci/pci.h      |   7 ++
> > >  include/hw/pci/pci_ea.h   |  39 +++++++++
> > >  include/hw/pci/pci_regs.h |   4 +
> > >  include/qemu/typedefs.h   |   1 +
> > >  7 files changed, 328 insertions(+), 24 deletions(-)
> > >  create mode 100644 hw/pci/pci_ea.c
> > >  create mode 100644 include/hw/pci/pci_ea.h