Re: [Xen-devel] [PATCH v6 7/9] xen: Put EFI machinery in place

Daniel Kiper
2014-06-23T13:58:50Z

On Mon, Jun 23, 2014 at 10:57:31AM +0100, David Vrabel wrote:
> On 20/06/14 22:29, Daniel Kiper wrote:
> > This patch enables EFI usage under Xen dom0. Standard EFI Linux
> > Kernel infrastructure cannot be used because it requires direct
> > access to EFI data and code. However, in dom0 case it is not possible
> > because above mentioned EFI stuff is fully owned and controlled
> > by Xen hypervisor. In this case all calls from dom0 to EFI must
> > be requested via special hypercall which in turn executes relevant
> > EFI code in behalf of dom0.
> >
> > When dom0 kernel boots it checks for EFI availability on a machine.
> > If it is detected then artificial EFI system table is filled.
> > Native EFI callas are replaced by functions which mimics them
> > by calling relevant hypercall. Later pointer to EFI system table
> > is passed to standard EFI machinery and it continues EFI subsystem
> > initialization taking into account that there is no direct access
> > to EFI boot services, runtime, tables, structures, etc. After that
> > system runs as usual.
>
> Reviewed-by: David Vrabel <david.vrabel@citrix.com>

Thanks for this and second one.

> (With or without the change suggested by Stefano).

I am going to take into account Stefano's idea.

Daniel