On Mon, Nov 14, 2011 at 1:23 PM, Keir Fraser keir@xen.org wrote:
On 14/11/2011 08:53, "Keir Fraser" keir.xen@gmail.com wrote:
On 14/11/2011 03:36, "Kevin O'Connor" kevin@koconnor.net wrote:
On Xen, the PCI init code isn't used, so assuming this struct doesn't
need to live in real "ram", I think it could live just about anywhere
past the end of ram. Even with pciinit.c, addresses over 0xfc00000
(with the exception of a few bytes for hpet, apic, ioapic, and bios
image) could be used.
I suggest we stick it at FC000000, and shift hvmloader's mem_alloc()
starting address up by one page to FC001000. The acpi build code will have
to manually mem_hole_populate_ram() that one page before writing to it. This
can then be documented in hvmloader/config.h which contains a description
of, and defines for, the system memory map. This is by far the easiest
solution to this problem; manually crafting an SSDT is a right pain in the
arse, whereas this is maybe a 5-line patch.
Like the attached patch (untested), which is a bit larger than anticipated,
but actually allows code to be net deleted. :-)
I just tested your patch with Windows 7 and Linux guest booted from iPXE.
Everything seems to work fine. SeaBIOS reports the following e820:
(XEN) HVM23: e820 map has 6 items:
(XEN) HVM23: 0: 0000000000000000 - 000000000009f400 = 1 RAM
(XEN) HVM23: 1: 000000000009f400 - 00000000000a0000 = 2 RESERVED
(XEN) HVM23: 2: 00000000000f0000 - 0000000000100000 = 2 RESERVED
(XEN) HVM23: 3: 0000000000100000 - 000000003f7ff000 = 1 RAM
(XEN) HVM23: 4: 000000003f7ff000 - 000000003f800000 = 2 RESERVED
(XEN) HVM23: 5: 00000000fc000000 - 0000000100000000 = 2 RESERVED
The ACPI code in Linux reports the right PCI memory window:
[ 0.338966] PCI: Using host bridge windows from ACPI; if necessary,
use "pci=nocrs" and report a bug
[ 0.340000] ACPI: PCI Root Bridge [PCI0] (domain 0000 [bus 00-ff])
[ 0.341029] pci_root PNP0A03:00: host bridge window [io 0x0000-0x0cf7]
[ 0.341965] pci_root PNP0A03:00: host bridge window [io 0x0d00-0xffff]
[ 0.342965] pci_root PNP0A03:00: host bridge window [mem
0x000a0000-0x000bffff]
[ 0.343965] pci_root PNP0A03:00: host bridge window [mem
0xf0000000-0xfbffffff]
Can you ship it ?
Done. Xen-unstable:24143
Keir Fraser