Hi Zhangfengwei,
Thank you for your patch.
I'm out of makedumpfile development, and the maintainer is Kumagai-San now.
So he will review this patch.
Kumagai-San, can you review this patch ?
Thanks
Ken'ichi Ohmichi
---
On Thu, 10 May 2012 20:07:33 +0800
Zhangfengwei <fngw.zhang at huawei.com> wrote:
>
> Hello,
> I find a bug of makedumpfile in a server with pages of 4KB,2MB and 1GB
> .
> The reason:
> When we get physical address by " kvtop_xen_x86_64()",Sometimes it is
> wrong;
> because the address maybe is an address of a page of 1GB ,when we get the
> physical address of L3 by L4.
> so we should judge if the address is in a page of 1GB ,which is the same
> with xen does.
>
> The xen codes(4.1.2) like this:
> in do_page_walk() of mm.c it does: if ( (l3e_get_flags(l3e) & _PAGE_PSE) )
> return mfn_to_virt(mfn) + (addr & ((1UL << L3_PAGETABLE_SHIFT) - 1));
>
> the code:
> void *do_page_walk(struct vcpu *v, unsigned long addr)
> {
> ...
> l4t = mfn_to_virt(mfn);
> l4e = l4t[l4_table_offset(addr)];
> mfn = l4e_get_pfn(l4e);
> if ( !(l4e_get_flags(l4e) & _PAGE_PRESENT) )
> return NULL;
> l3t = mfn_to_virt(mfn);
> l3e = l3t[l3_table_offset(addr)];
> mfn = l3e_get_pfn(l3e);
> if ( !(l3e_get_flags(l3e) & _PAGE_PRESENT) || !mfn_valid(mfn) )
> return NULL;
> if ( (l3e_get_flags(l3e) & _PAGE_PSE) )
> return mfn_to_virt(mfn) + (addr & ((1UL << L3_PAGETABLE_SHIFT) -
> 1));
> ...
> }
>
> So the patch is like this:
>
> diff -urN makedumpfile-org/x86_64.c makedumpfile/x86_64.c
> --- makedumpfile-org/x86_64.c 2012-05-07 04:29:19.000000000 -0500
> +++ makedumpfile/x86_64.c 2012-05-07 04:29:39.000000000 -0500
> @@ -392,6 +392,13 @@
> if (!(entry & _PAGE_PRESENT))
> return NOT_PADDR;
>
> + if (entry & _PAGE_PSE) {
> + entry = (entry & ENTRY_MASK) + (kvaddr & ((1UL <<
> PGDIR_SHIFT) - 1));
> + if( is_xen_frametable_addr(kvaddr) )
> + insert_xvaddr_xpaddr_fn(kvaddr,entry);
> + return entry;
> + }
> +
> dirp = entry & ENTRY_MASK;
> dirp += pmd_index(kvaddr) * sizeof(unsigned long long);
> if (!readmem(MADDR_XEN, dirp, &entry, sizeof(entry)))
>
> I am looking forward to receive your reply as soon as possible.
> thanks
>
