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  1. 17 8月, 2011 1 次提交
    • J
      xen/x86: replace order-based range checking of M2P table by linear one · ccbcdf7c
      由 Jan Beulich 提交于 
      The order-based approach is not only less efficient (requiring a shift
and a compare, typical generated code looking like this

	mov	eax, [machine_to_phys_order]
	mov	ecx, eax
	shr	ebx, cl
	test	ebx, ebx
	jnz	...

whereas a direct check requires just a compare, like in

	cmp	ebx, [machine_to_phys_nr]
	jae	...

), but also slightly dangerous in the 32-on-64 case - the element
address calculation can wrap if the next power of two boundary is
sufficiently far away from the actual upper limit of the table, and
hence can result in user space addresses being accessed (with it being
unknown what may actually be mapped there).

Additionally, the elimination of the mistaken use of fls() here (should
have been __fls()) fixes a latent issue on x86-64 that would trigger
if the code was run on a system with memory extending beyond the 44-bit
boundary.

CC: stable@kernel.org
Signed-off-by: NJan Beulich <jbeulich@novell.com>
[v1: Based on Jeremy's feedback]
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      ccbcdf7c
  3. 19 7月, 2011 6 次提交
  5. 30 6月, 2011 1 次提交
  7. 16 6月, 2011 1 次提交
    • A
      xen: support CONFIG_MAXSMP · 900cba88
      由 Andrew Jones 提交于 
      The MAXSMP config option requires CPUMASK_OFFSTACK, which in turn
requires we init the memory for the maps while we bring up the cpus.
MAXSMP also increases NR_CPUS to 4096. This increase in size exposed an
issue in the argument construction for multicalls from
xen_flush_tlb_others. The args should only need space for the actual
number of cpus.

Also in 2.6.39 it exposes a bootup problem.

BUG: unable to handle kernel NULL pointer dereference at           (null)
IP: [<ffffffff8157a1d3>] set_cpu_sibling_map+0x123/0x30d
...
Call Trace:
[<ffffffff81039a3f>] ? xen_restore_fl_direct_reloc+0x4/0x4
[<ffffffff819dc4db>] xen_smp_prepare_cpus+0x36/0x135
..

CC: stable@kernel.org
Signed-off-by: NAndrew Jones <drjones@redhat.com>
[v2: Updated to compile on 3.0]
[v3: Updated to compile when CONFIG_SMP is not defined]
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      900cba88
  9. 09 6月, 2011 1 次提交
  11. 21 5月, 2011 9 次提交
  13. 19 5月, 2011 1 次提交
  15. 13 5月, 2011 3 次提交
    • T
      xen mmu: fix a race window causing leave_mm BUG() · 7899891c
      由 Tian, Kevin 提交于 
      There's a race window in xen_drop_mm_ref, where remote cpu may exit
dirty bitmap between the check on this cpu and the point where remote
cpu handles drop request. So in drop_other_mm_ref we need check
whether TLB state is still lazy before calling into leave_mm. This
bug is rarely observed in earlier kernel, but exaggerated by the
commit 831d52bc
("x86, mm: avoid possible bogus tlb entries by clearing prev mm_cpumask after switching mm")
which clears bitmap after changing the TLB state. the call trace is as below:

---------------------------------
kernel BUG at arch/x86/mm/tlb.c:61!
invalid opcode: 0000 [#1] SMP
last sysfs file: /sys/devices/system/xen_memory/xen_memory0/info/current_kb
CPU 1
Modules linked in: 8021q garp xen_netback xen_blkback blktap blkback_pagemap nbd bridge stp llc autofs4 ipmi_devintf ipmi_si ipmi_msghandler lockd sunrpc bonding ipv6 xenfs dm_multipath video output sbs sbshc parport_pc lp parport ses enclosure snd_seq_dummy snd_seq_oss snd_seq_midi_event snd_seq snd_seq_device serio_raw bnx2 snd_pcm_oss snd_mixer_oss snd_pcm snd_timer iTCO_wdt snd soundcore snd_page_alloc i2c_i801 iTCO_vendor_support i2c_core pcs pkr pata_acpi ata_generic ata_piix shpchp mptsas mptscsih mptbase [last unloaded: freq_table]
Pid: 25581, comm: khelper Not tainted 2.6.32.36fixxen #1 Tecal RH2285
RIP: e030:[<ffffffff8103a3cb>]  [<ffffffff8103a3cb>] leave_mm+0x15/0x46
RSP: e02b:ffff88002805be48  EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffff88015f8e2da0
RDX: ffff88002805be78 RSI: 0000000000000000 RDI: 0000000000000001
RBP: ffff88002805be48 R08: ffff88009d662000 R09: dead000000200200
R10: dead000000100100 R11: ffffffff814472b2 R12: ffff88009bfc1880
R13: ffff880028063020 R14: 00000000000004f6 R15: 0000000000000000
FS:  00007f62362d66e0(0000) GS:ffff880028058000(0000) knlGS:0000000000000000
CS:  e033 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 0000003aabc11909 CR3: 000000009b8ca000 CR4: 0000000000002660
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 00000000000000 00
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process khelper (pid: 25581, threadinfo ffff88007691e000, task ffff88009b92db40)
Stack:
 ffff88002805be68 ffffffff8100e4ae 0000000000000001 ffff88009d733b88
<0> ffff88002805be98 ffffffff81087224 ffff88002805be78 ffff88002805be78
<0> ffff88015f808360 00000000000004f6 ffff88002805bea8 ffffffff81010108
Call Trace:
 <IRQ>
 [<ffffffff8100e4ae>] drop_other_mm_ref+0x2a/0x53
 [<ffffffff81087224>] generic_smp_call_function_single_interrupt+0xd8/0xfc
 [<ffffffff81010108>] xen_call_function_single_interrupt+0x13/0x28
 [<ffffffff810a936a>] handle_IRQ_event+0x66/0x120
 [<ffffffff810aac5b>] handle_percpu_irq+0x41/0x6e
 [<ffffffff8128c1c0>] __xen_evtchn_do_upcall+0x1ab/0x27d
 [<ffffffff8128dd11>] xen_evtchn_do_upcall+0x33/0x46
 [<ffffffff81013efe>] xen_do_hyper visor_callback+0x1e/0x30
 <EOI>
 [<ffffffff814472b2>] ? _spin_unlock_irqrestore+0x15/0x17
 [<ffffffff8100f8cf>] ? xen_restore_fl_direct_end+0x0/0x1
 [<ffffffff81113f71>] ? flush_old_exec+0x3ac/0x500
 [<ffffffff81150dc5>] ? load_elf_binary+0x0/0x17ef
 [<ffffffff81150dc5>] ? load_elf_binary+0x0/0x17ef
 [<ffffffff8115115d>] ? load_elf_binary+0x398/0x17ef
 [<ffffffff81042fcf>] ? need_resched+0x23/0x2d
 [<ffffffff811f4648>] ? process_measurement+0xc0/0xd7
 [<ffffffff81150dc5>] ? load_elf_binary+0x0/0x17ef
 [<ffffffff81113094>] ? search_binary_handler+0xc8/0x255
 [<ffffffff81114362>] ? do_execve+0x1c3/0x29e
 [<ffffffff8101155d>] ? sys_execve+0x43/0x5d
 [<ffffffff8106fc45>] ? __call_usermodehelper+0x0/0x6f
 [<ffffffff81013e28>] ? kernel_execve+0x68/0xd0
 [<ffffffff 8106fc45>] ? __call_usermodehelper+0x0/0x6f
 [<ffffffff8100f8cf>] ? xen_restore_fl_direct_end+0x0/0x1
 [<ffffffff8106fb64>] ? ____call_usermodehelper+0x113/0x11e
 [<ffffffff81013daa>] ? child_rip+0xa/0x20
 [<ffffffff8106fc45>] ? __call_usermodehelper+0x0/0x6f
 [<ffffffff81012f91>] ? int_ret_from_sys_call+0x7/0x1b
 [<ffffffff8101371d>] ? retint_restore_args+0x5/0x6
 [<ffffffff81013da0>] ? child_rip+0x0/0x20
Code: 41 5e 41 5f c9 c3 55 48 89 e5 0f 1f 44 00 00 e8 17 ff ff ff c9 c3 55 48 89 e5 0f 1f 44 00 00 65 8b 04 25 c8 55 01 00 ff c8 75 04 <0f> 0b eb fe 65 48 8b 34 25 c0 55 01 00 48 81 c6 b8 02 00 00 e8
RIP  [<ffffffff8103a3cb>] leave_mm+0x15/0x46
 RSP <ffff88002805be48>
---[ end trace ce9cee6832a9c503 ]---

Tested-by: Maoxiaoyun<tinnycloud@hotmail.com>
Signed-off-by: NKevin Tian <kevin.tian@intel.com>
[v1: Fleshed out the git description a bit]
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      7899891c
    • S
      x86,xen: introduce x86_init.mapping.pagetable_reserve · 279b706b
      由 Stefano Stabellini 提交于 
      Introduce a new x86_init hook called pagetable_reserve that at the end
of init_memory_mapping is used to reserve a range of memory addresses for
the kernel pagetable pages we used and free the other ones.

On native it just calls memblock_x86_reserve_range while on xen it also
takes care of setting the spare memory previously allocated
for kernel pagetable pages from RO to RW, so that it can be used for
other purposes.

A detailed explanation of the reason why this hook is needed follows.

As a consequence of the commit:

commit 4b239f45
Author: Yinghai Lu <yinghai@kernel.org>
Date:   Fri Dec 17 16:58:28 2010 -0800

    x86-64, mm: Put early page table high

at some point init_memory_mapping is going to reach the pagetable pages
area and map those pages too (mapping them as normal memory that falls
in the range of addresses passed to init_memory_mapping as argument).
Some of those pages are already pagetable pages (they are in the range
pgt_buf_start-pgt_buf_end) therefore they are going to be mapped RO and
everything is fine.
Some of these pages are not pagetable pages yet (they fall in the range
pgt_buf_end-pgt_buf_top; for example the page at pgt_buf_end) so they
are going to be mapped RW.  When these pages become pagetable pages and
are hooked into the pagetable, xen will find that the guest has already
a RW mapping of them somewhere and fail the operation.
The reason Xen requires pagetables to be RO is that the hypervisor needs
to verify that the pagetables are valid before using them. The validation
operations are called "pinning" (more details in arch/x86/xen/mmu.c).

In order to fix the issue we mark all the pages in the entire range
pgt_buf_start-pgt_buf_top as RO, however when the pagetable allocation
is completed only the range pgt_buf_start-pgt_buf_end is reserved by
init_memory_mapping. Hence the kernel is going to crash as soon as one
of the pages in the range pgt_buf_end-pgt_buf_top is reused (b/c those
ranges are RO).

For this reason we need a hook to reserve the kernel pagetable pages we
used and free the other ones so that they can be reused for other
purposes.
On native it just means calling memblock_x86_reserve_range, on Xen it
also means marking RW the pagetable pages that we allocated before but
that haven't been used before.

Another way to fix this is without using the hook is by adding a 'if
(xen_pv_domain)' in the 'init_memory_mapping' code and calling the Xen
counterpart, but that is just nasty.
Signed-off-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>
Acked-by: NH. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      279b706b
    • K
      Revert "xen/mmu: Add workaround "x86-64, mm: Put early page table high"" · 92bdaef7
      由 Konrad Rzeszutek Wilk 提交于 
      This reverts commit a3864783.

It does not work with certain AMD machines.

last_pfn = 0x100000 max_arch_pfn = 0x400000000
initial memory mapped : 0 - 02c3a000
Base memory trampoline at [ffff88000009b000] 9b000 size 20480
init_memory_mapping: 0000000000000000-0000000100000000
 0000000000 - 0100000000 page 4k
kernel direct mapping tables up to 100000000 @ ff7fb000-100000000
init_memory_mapping: 0000000100000000-00000001e0800000
 0100000000 - 01e0800000 page 4k
kernel direct mapping tables up to 1e0800000 @ 1df0f3000-1e0000000
xen: setting RW the range fffdc000 - 100000000
RAMDISK: 0203b000 - 02c3a000
No NUMA configuration found
Faking a node at 0000000000000000-00000001e0800000
NUMA: Using 63 for the hash shift.
Initmem setup node 0 0000000000000000-00000001e0800000
  NODE_DATA [00000001dfffb000 - 00000001dfffffff]
BUG: unable to handle kernel NULL pointer dereference at           (null)
IP: [<ffffffff81cf6a75>] setup_node_bootmem+0x18a/0x1ea
PGD 0
Oops: 0003 [#1] SMP
last sysfs file:
CPU 0
Modules linked in:

Pid: 0, comm: swapper Not tainted 2.6.39-0-virtual #6~smb1
RIP: e030:[<ffffffff81cf6a75>]  [<ffffffff81cf6a75>] setup_node_bootmem+0x18a/0x1ea
RSP: e02b:ffffffff81c01e38  EFLAGS: 00010046
RAX: 0000000000000000 RBX: 00000001e0800000 RCX: 0000000000001040
RDX: 0000000000004100 RSI: 0000000000000000 RDI: ffff8801dfffb000
RBP: ffffffff81c01e58 R08: 0000000000000020 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000bfe400
FS:  0000000000000000(0000) GS:ffffffff81cca000(0000) knlGS:0000000000000000
CS:  e033 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000001c03000 CR4: 0000000000000660
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process swapper (pid: 0, threadinfo ffffffff81c00000, task ffffffff81c0b020)
Stack:
 0000000000000040 0000000000000001 0000000000000000 ffffffffffffffff
 ffffffff81c01e88 ffffffff81cf6c25 0000000000000000 0000000000000000
 ffffffff81cf687f 0000000000000000 ffffffff81c01ea8 ffffffff81cf6e45
Call Trace:
 [<ffffffff81cf6c25>] numa_register_memblks.constprop.3+0x150/0x181
 [<ffffffff81cf687f>] ? numa_add_memblk+0x7c/0x7c
 [<ffffffff81cf6e45>] numa_init.part.2+0x1c/0x7c
 [<ffffffff81cf687f>] ? numa_add_memblk+0x7c/0x7c
 [<ffffffff81cf6f67>] numa_init+0x6c/0x70
 [<ffffffff81cf7057>] initmem_init+0x39/0x3b
 [<ffffffff81ce5865>] setup_arch+0x64e/0x769
 [<ffffffff815e43c1>] ? printk+0x51/0x53
 [<ffffffff81cdf92b>] start_kernel+0xd4/0x3f3
 [<ffffffff81cdf388>] x86_64_start_reservations+0x132/0x136
 [<ffffffff81ce2ed4>] xen_start_kernel+0x588/0x58f
Code: 41 00 00 48 8b 3c c5 a0 24 cc 81 31 c0 40 f6 c7 01 74 05 aa 66 ba ff 40 40 f6 c7 02 74 05 66 ab 83 ea 02 89 d1 c1 e9 02 f6 c2 02 <f3> ab 74 02 66 ab 80 e2 01 74 01 aa 49 63 c4 48 c1 eb 0c 44 89
RIP  [<ffffffff81cf6a75>] setup_node_bootmem+0x18a/0x1ea
 RSP <ffffffff81c01e38>
CR2: 0000000000000000
---[ end trace a7919e7f17c0a725 ]---
Kernel panic - not syncing: Attempted to kill the idle task!
Pid: 0, comm: swapper Tainted: G      D     2.6.39-0-virtual #6~smb1
Reported-by: NStefan Bader <stefan.bader@canonical.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      92bdaef7
  17. 03 5月, 2011 2 次提交
    • S
      xen: mask_rw_pte mark RO all pagetable pages up to pgt_buf_top · b9269dc7
      由 Stefano Stabellini 提交于 
      mask_rw_pte is currently checking if a pfn is a pagetable page if it
falls in the range pgt_buf_start - pgt_buf_end but that is incorrect
because pgt_buf_end is a moving target: pgt_buf_top is the real
boundary.
Acked-by: N"H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      b9269dc7
    • K
      xen/mmu: Add workaround "x86-64, mm: Put early page table high" · a3864783
      由 Konrad Rzeszutek Wilk 提交于 
      As a consequence of the commit:

commit 4b239f45
Author: Yinghai Lu <yinghai@kernel.org>
Date:   Fri Dec 17 16:58:28 2010 -0800

    x86-64, mm: Put early page table high

it causes the Linux kernel to crash under Xen:

mapping kernel into physical memory
Xen: setup ISA identity maps
about to get started...
(XEN) mm.c:2466:d0 Bad type (saw 7400000000000001 != exp 1000000000000000) for mfn b1d89 (pfn bacf7)
(XEN) mm.c:3027:d0 Error while pinning mfn b1d89
(XEN) traps.c:481:d0 Unhandled invalid opcode fault/trap [#6] on VCPU 0 [ec=0000]
(XEN) domain_crash_sync called from entry.S
(XEN) Domain 0 (vcpu#0) crashed on cpu#0:
...

The reason is that at some point init_memory_mapping is going to reach
the pagetable pages area and map those pages too (mapping them as normal
memory that falls in the range of addresses passed to init_memory_mapping
as argument). Some of those pages are already pagetable pages (they are
in the range pgt_buf_start-pgt_buf_end) therefore they are going to be
mapped RO and everything is fine.
Some of these pages are not pagetable pages yet (they fall in the range
pgt_buf_end-pgt_buf_top; for example the page at pgt_buf_end) so they
are going to be mapped RW.  When these pages become pagetable pages and
are hooked into the pagetable, xen will find that the guest has already
a RW mapping of them somewhere and fail the operation.
The reason Xen requires pagetables to be RO is that the hypervisor needs
to verify that the pagetables are valid before using them. The validation
operations are called "pinning" (more details in arch/x86/xen/mmu.c).

In order to fix the issue we mark all the pages in the entire range
pgt_buf_start-pgt_buf_top as RO, however when the pagetable allocation
is completed only the range pgt_buf_start-pgt_buf_end is reserved by
init_memory_mapping. Hence the kernel is going to crash as soon as one
of the pages in the range pgt_buf_end-pgt_buf_top is reused (b/c those
ranges are RO).

For this reason, this function is introduced which is called _after_
the init_memory_mapping has completed (in a perfect world we would
call this function from init_memory_mapping, but lets ignore that).

Because we are called _after_ init_memory_mapping the pgt_buf_[start,
end,top] have all changed to new values (b/c another init_memory_mapping
is called). Hence, the first time we enter this function, we save
away the pgt_buf_start value and update the pgt_buf_[end,top].

When we detect that the "old" pgt_buf_start through pgt_buf_end
PFNs have been reserved (so memblock_x86_reserve_range has been called),
we immediately set out to RW the "old" pgt_buf_end through pgt_buf_top.

And then we update those "old" pgt_buf_[end|top] with the new ones
so that we can redo this on the next pagetable.
Acked-by: N"H. Peter Anvin" <hpa@zytor.com>
Reviewed-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
[v1: Updated with Jeremy's comments]
[v2: Added the crash output]
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      a3864783
  19. 20 4月, 2011 1 次提交
    • S
      xen: mask_rw_pte: do not apply the early_ioremap checks on x86_32 · ee176455
      由 Stefano Stabellini 提交于 
      The two "is_early_ioremap_ptep" checks in mask_rw_pte are only used on
x86_64, in fact early_ioremap is not used at all to setup the initial
pagetable on x86_32.
Moreover on x86_32 the two checks are wrong because the range
pgt_buf_start..pgt_buf_end initially should be mapped RW because
the pages in the range are not pagetable pages yet and haven't been
cleared yet. Afterwards considering the pgt_buf_start..pgt_buf_end is
part of the initial mapping, xen_alloc_pte is capable of turning
the ptes RO when they become pagetable pages.

Fix the issue and improve the readability of the code providing two
different implementation of mask_rw_pte for x86_32 and x86_64.
Signed-off-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      ee176455
  21. 05 4月, 2011 1 次提交
  23. 20 3月, 2011 2 次提交
    • S
      xen: update mask_rw_pte after kernel page tables init changes · d8aa5ec3
      由 Stefano Stabellini 提交于 
      After "x86-64, mm: Put early page table high" already existing kernel
page table pages can be mapped using early_ioremap too so we need to
update mask_rw_pte to make sure these pages are still mapped RO.
The reason why we have to do that is explain by the commit message of
fef5ba79:

"Xen requires that all pages containing pagetable entries to be mapped
read-only.  If pages used for the initial pagetable are already mapped
then we can change the mapping to RO.  However, if they are initially
unmapped, we need to make sure that when they are later mapped, they
are also mapped RO.

..SNIP..

the pagetable setup code early_ioremaps the pages to write their
entries, so we must make sure that mappings created in the early_ioremap
fixmap area are mapped RW.  (Those mappings are removed before the pages
are presented to Xen as pagetable pages.)"

We accomplish all this in mask_rw_pte by mapping RO all the pages mapped
using early_ioremap apart from the last one that has been allocated
because it is not a page table page yet (it has not been hooked into the
page tables yet).
Signed-off-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
LKML-Reference: <alpine.DEB.2.00.1103171739050.3382@kaball-desktop>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
      d8aa5ec3
    • S
      xen: set max_pfn_mapped to the last pfn mapped · 14988a4d
      由 Stefano Stabellini 提交于 
      Do not set max_pfn_mapped to the end of the initial memory mappings,
that also contain pages that don't belong in pfn space (like the mfn
list).

Set max_pfn_mapped to the last real pfn mapped in the initial memory
mappings that is the pfn backing _end.
Signed-off-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
LKML-Reference: <alpine.DEB.2.00.1103171739050.3382@kaball-desktop>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
      14988a4d
  25. 18 3月, 2011 1 次提交
  27. 14 3月, 2011 4 次提交
  29. 10 3月, 2011 1 次提交
  31. 04 3月, 2011 1 次提交
    • K
      xen: Mark all initial reserved pages for the balloon as INVALID_P2M_ENTRY. · 6eaa412f
      由 Konrad Rzeszutek Wilk 提交于 
      With this patch, we diligently set regions that will be used by the
balloon driver to be INVALID_P2M_ENTRY and under the ownership
of the balloon driver. We are OK using the __set_phys_to_machine
as we do not expect to be allocating any P2M middle or entries pages.
The set_phys_to_machine has the side-effect of potentially allocating
new pages and we do not want that at this stage.

We can do this because xen_build_mfn_list_list will have already
allocated all such pages up to xen_max_p2m_pfn.

We also move the check for auto translated physmap down the
stack so it is present in __set_phys_to_machine.

[v2: Rebased with mmu->p2m code split]
Reviewed-by: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      6eaa412f
  33. 24 2月, 2011 1 次提交
    • Y
      x86: Rename e820_table_* to pgt_buf_* · d1b19426
      由 Yinghai Lu 提交于 
      e820_table_{start|end|top}, which are used to buffer page table
allocation during early boot, are now derived from memblock and don't
have much to do with e820.  Change the names so that they reflect what
they're used for.

This patch doesn't introduce any behavior change.

-v2: Ingo found that earlier patch "x86: Use early pre-allocated page
     table buffer top-down" caused crash on 32bit and needed to be
     dropped.  This patch was updated to reflect the change.

-tj: Updated commit description.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NTejun Heo <tj@kernel.org>
      d1b19426
  35. 15 1月, 2011 1 次提交
  37. 12 1月, 2011 1 次提交
  39. 03 12月, 2010 1 次提交
    • J
      vmalloc: eagerly clear ptes on vunmap · 64141da5
      由 Jeremy Fitzhardinge 提交于 
      On stock 2.6.37-rc4, running:

  # mount lilith:/export /mnt/lilith
  # find  /mnt/lilith/ -type f -print0 | xargs -0 file

crashes the machine fairly quickly under Xen.  Often it results in oops
messages, but the couple of times I tried just now, it just hung quietly
and made Xen print some rude messages:

    (XEN) mm.c:2389:d80 Bad type (saw 7400000000000001 != exp
    3000000000000000) for mfn 1d7058 (pfn 18fa7)
    (XEN) mm.c:964:d80 Attempt to create linear p.t. with write perms
    (XEN) mm.c:2389:d80 Bad type (saw 7400000000000010 != exp
    1000000000000000) for mfn 1d2e04 (pfn 1d1fb)
    (XEN) mm.c:2965:d80 Error while pinning mfn 1d2e04

Which means the domain tried to map a pagetable page RW, which would
allow it to map arbitrary memory, so Xen stopped it.  This is because
vm_unmap_ram() left some pages mapped in the vmalloc area after NFS had
finished with them, and those pages got recycled as pagetable pages
while still having these RW aliases.

Removing those mappings immediately removes the Xen-visible aliases, and
so it has no problem with those pages being reused as pagetable pages.
Deferring the TLB flush doesn't upset Xen because it can flush the TLB
itself as needed to maintain its invariants.

When unmapping a region in the vmalloc space, clear the ptes
immediately.  There's no point in deferring this because there's no
amortization benefit.

The TLBs are left dirty, and they are flushed lazily to amortize the
cost of the IPIs.

This specific motivation for this patch is an oops-causing regression
since 2.6.36 when using NFS under Xen, triggered by the NFS client's use
of vm_map_ram() introduced in 56e4ebf8 ("NFS: readdir with vmapped
pages") .  XFS also uses vm_map_ram() and could cause similar problems.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Bryan Schumaker <bjschuma@netapp.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Alex Elder <aelder@sgi.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      64141da5