Re: [Xen-devel] [PATCH 1/2] x86/efi: Reserve SMBIOS table region when EFI booting

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 02.04.15 at 10:24, <ross.lagerwall@xxxxxxxxxx> wrote:
> Some EFI firmware implementations may place the SMBIOS table in RAM
> marked as BootServicesData, which Xen does not consider as reserved.
> When dom0 tries to access the SMBIOS, the region is not contained in the
> initial P2M and it crashes with a page fault. To fix this, reserve the
> SMBIOS region.
> 
> Also, fix the memcmp check for existence of the SMBIOS

As Andrew said, put the memcmp() fixes all in a separate patch, or
fold the one remaining one in here.

> and the DMI
> checksum calculation.

This I don't agree with, and even less so without explanation. The
spec says

"15h
 Intermediate Checksum
 BYTE
 Checksum of Intermediate Entry Point Structure (IEPS). This value,
 when added to all other bytes in the IEPS, results in the value 00h
 (using 8-bit addition calculations). Values in the IEPS are summed
 starting at offset 10h, for 0Fh bytes."

I.e. I can't see why the sizeof() you replace would be wrong (other
than for broken firmware).

Jan


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel