[Xen-devel] [PATCH] uses CPUID instruction virtualization to workaround VMXAssist 4G limit

["Li, Xin B" <xin.b.li@xxxxxxxxx>]

uses CPUID instruction virtualization to workaround VMXAssist 4G limit.
Address space access limit in VMXAssist is 4G, because IA-32 only has 4G
virtual address space which VMXassist can use to map physical memory.
The issue is, win2k3 server with more than 4G memory will put AP GDT
above 4G, so when AP changes its mode from real mode to PAE paging mode,
the long jump instrction it uses need access AP GDT entries which
resides above 4G, but because of this constraint, it can not access GDT
and so fails boot.

Signed-off-by: Xin Li <xin.b.li@xxxxxxxxx>

Attachment: vmxassist_4g.cpuid.patch
Description: vmxassist_4g.cpuid.patch

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