Re: [Xen-ia64-devel] [Q] about assign_domain_page_replace

[Akio Takebe <takebe_akio@xxxxxxxxxxxxxx>]

Hi, Isaku

I'm sorry for lately reply.

>On Wed, Jun 06, 2007 at 04:31:16PM +0900, Akio Takebe wrote:
>
>> >domain_page_flush_and_put() isn't aware of NULL-owner pages, I'll fix it.
>> >However more issues seem to be there.
>
>I sent out the patch which fixes p2m exposure issues.
>But I don't think that the patch doesn't resolve your issues.
>At least it only conceals issues. It's worse than panic.
>
Yes, as you said, when I retried with your patch,
dom0 panic is not occurred.
I attach the xm dmesg log. (it use the attached patch)

>> 
>> The result of booting domU is below.
>
>There seems to be several issues. Hmmmm...
>What domains correspond to 32896 and 61177984?
>I guesss
>  _domain=61177984 => dom0
>  _domain=32896    => newly created domain.
>Is those correct?
Yes, you're right.

>foreign domain page mapping doesn't seem to work correctly.
>domain builder seems to map a page which belongs to newly created domain.
>If so, it shouldn't be that old_mfn->count_info=0,
>old_mfn->u.inuse._domain=0.
>Can you confirm the following?
>
>  - Does dom0 issue this hypercall? (i.e. what's currnet domain?)
>
Yes.
This issue seems to be happend at the following hypercalls.
xen_ia64_dom_fw_setup: xen_ia64_dom_fw_map (hypercall page=0x0)
xen_ia64_dom_fw_setup: xen_ia64_dom_fw_map (fw table=0x2000)
xen_ia64_dom_fw_setup: xen_ia64_dom_fw_map (acpi table=0x1000)


When I add more debug messages, I get the following message.
I specified 512MB of domU memory, so page of gmfn=0x7ffd is start_info page.
And page of mfn_or_gmfn =0x0 is fw pages.

(XEN) __dom0vp_add_physmap:d 0xf000000007bf0080 domid 0 gpfn 0x1024d6f 
mfn_or_gmfn 0x1659 flags 0x0 domid 1
(XEN) __dom0vp_add_physmap:d 0xf000000007bf0080 domid 0 gpfn 0x1026800 
mfn_or_gmfn 0x7ffc flags 0x0 domid 1
(XEN) __dom0vp_add_physmap:d 0xf000000007bf0080 domid 0 gpfn 0x1026800 
mfn_or_gmfn 0x7ffd flags 0x0 domid 1
(XEN) __dom0vp_add_physmap:d 0xf000000007bf0080 domid 0 gpfn 0x1026800 
mfn_or_gmfn 0x0 flags 0x0 domid 1
(XEN) __dom0vp_add_physmap:d 0xf000000007bf0080 domid 0 gpfn 0x1026c00 
mfn_or_gmfn 0x0 flags 0x0 domid 1
(XEN) __dom0vp_add_physmap:d 0xf000000007bf0080 domid 0 gpfn 0x1027000 
mfn_or_gmfn 0x0 flags 0x0 domid 1
(XEN) mfn=0x000000000102003d, old_mfn=0x0000000001020001
(XEN) assign_domain_page_replace: old_mfn->count_info=1155
(XEN) assign_domain_page_replace: mfn->count_info=4
(XEN) assign_domain_page_replace: (domain_id of old_mfn)=32760
(XEN) assign_domain_page_replace: (domain_id of mfn)=1
(XEN) 
(XEN) Call Trace:
(XEN)  [<f0000000040ab630>] show_stack+0x80/0xa0
(XEN)                                 sp=f000000007bcfc10 bsp=f000000007bc9350
(XEN)  [<f00000000406fab0>] assign_domain_page_replace+0x2d0/0x3d0
(XEN)                                 sp=f000000007bcfde0 bsp=f000000007bc92f8
(XEN)  [<f000000004070e80>] __dom0vp_add_physmap+0x370/0x660
(XEN)                                 sp=f000000007bcfde0 bsp=f000000007bc9298
(XEN)  [<f0000000040524e0>] do_dom0vp_op+0x1e0/0x4d0
(XEN)                                 sp=f000000007bcfdf0 bsp=f000000007bc9258
(XEN)  [<f000000004002e30>] fast_hypercall+0x170/0x340
(XEN)                                 sp=f000000007bcfe00 bsp=f000000007bc9258

>  - If so, what's pseudo physical address of dom0?
>    I guess it is in p2m table table area. Is this correct?
>    You can find the area by cat /proc/iomem | grep 'Xen p2m table'
>    or finding dom0 kernel boot message like the following
>
>    > Xen p2m: to [0x0000000300000000, 0x0000000303ffc000) (65536 KBytes)
>
>If the above guess is correct, then destroying domain shouldn't cause panic.
>Can you check mfn which causes panic?
>
No, the address is not in p2m table.

hex(0x1027000 << 14)==> '0x409c000000'
# cat /proc/iomem |grep Xen
4094000000-4097ffffff : Xen p2m table


Best Regards,

Akio Takebe

Attachment: serial.log
Description: Binary data

Attachment: patch
Description: Binary data

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