On Thu, 2008-02-21 at 13:37 -0800, Jeremy Fitzhardinge wrote:H. Peter Anvin wrote:Hm, I don't think so. The domain-builder pagetable is put after the kernel, so it shouldn't be under 1M.Still curious about why a pagetable page is ending up in that range though. Seems like it shouldn't be possible, since we shouldn't be allowed to allocate from those pages, at least until the DMI probe has happened... Unless the early allocator is only excluded from e820 reserved pages, which would cause a problem on systems which don't reserve the DMI space... HPA?I thought the problem was a Xen-provided pagetable from before Linux started?
I can confirm that it is Linux which is allocating it. The call path:
# xm create -c debian-x86_32p-1
Using config file "/etc/xen/debian-x86_32p-1".
Started domain debian-1
xen_alloc_pt_init PFN f0
Pid: 0, comm: swapper Not tainted 2.6.25-rc2 #68
[<c02ecb6b>] xen_alloc_pt_init+0x4b/0x60
[<c02f5e2b>] one_page_table_init+0x8b/0xf0
[<c02f63df>] paging_init+0x3bf/0x520
[<c02ee444>] setup_arch+0x2a4/0x410
[<c02e9a64>] start_kernel+0x64/0x380
[<c02efd7f>] cpu_detect+0x6f/0xf0
[<c02ed1a1>] xen_start_kernel+0x2f1/0x310
=======================
Entering add_active_range(0, 0, 262144) 0 entries of 256 used
Zone PFN ranges:
DMA 0 -> 4096