Commit Graph

780 Commits

Author SHA1 Message Date
Konrad Rzeszutek Wilk
7f9140626c xen/mmu: Copy and revector the P2M tree.
Please first read the description in "xen/p2m: Add logic to revector a
P2M tree to use __va leafs" patch.

The 'xen_revector_p2m_tree()' function allocates a new P2M tree
copies the contents of the old one in it, and returns the new one.

At this stage, the __ka address space (which is what the old
P2M tree was using) is partially disassembled. The cleanup_highmap
has removed the PMD entries from 0-16MB and anything past _brk_end
up to the max_pfn_mapped (which is the end of the ramdisk).

We have revectored the P2M tree (and the one for save/restore as well)
to use new shiny __va address to new MFNs. The xen_start_info
has been taken care of already in 'xen_setup_kernel_pagetable()' and
xen_start_info->shared_info in 'xen_setup_shared_info()', so
we are free to roam and delete PMD entries - which is exactly what
we are going to do. We rip out the __ka for the old P2M array.

[v1: Fix smatch warnings]
[v2: memset was doing 0 instead of 0xff]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-08-23 11:52:14 -04:00
Konrad Rzeszutek Wilk
357a3cfb14 xen/p2m: Add logic to revector a P2M tree to use __va leafs.
During bootup Xen supplies us with a P2M array. It sticks
it right after the ramdisk, as can be seen with a 128GB PV guest:

(certain parts removed for clarity):
xc_dom_build_image: called
xc_dom_alloc_segment:   kernel       : 0xffffffff81000000 -> 0xffffffff81e43000  (pfn 0x1000 + 0xe43 pages)
xc_dom_pfn_to_ptr: domU mapping: pfn 0x1000+0xe43 at 0x7f097d8bf000
xc_dom_alloc_segment:   ramdisk      : 0xffffffff81e43000 -> 0xffffffff925c7000  (pfn 0x1e43 + 0x10784 pages)
xc_dom_pfn_to_ptr: domU mapping: pfn 0x1e43+0x10784 at 0x7f0952dd2000
xc_dom_alloc_segment:   phys2mach    : 0xffffffff925c7000 -> 0xffffffffa25c7000  (pfn 0x125c7 + 0x10000 pages)
xc_dom_pfn_to_ptr: domU mapping: pfn 0x125c7+0x10000 at 0x7f0942dd2000
xc_dom_alloc_page   :   start info   : 0xffffffffa25c7000 (pfn 0x225c7)
xc_dom_alloc_page   :   xenstore     : 0xffffffffa25c8000 (pfn 0x225c8)
xc_dom_alloc_page   :   console      : 0xffffffffa25c9000 (pfn 0x225c9)
nr_page_tables: 0x0000ffffffffffff/48: 0xffff000000000000 -> 0xffffffffffffffff, 1 table(s)
nr_page_tables: 0x0000007fffffffff/39: 0xffffff8000000000 -> 0xffffffffffffffff, 1 table(s)
nr_page_tables: 0x000000003fffffff/30: 0xffffffff80000000 -> 0xffffffffbfffffff, 1 table(s)
nr_page_tables: 0x00000000001fffff/21: 0xffffffff80000000 -> 0xffffffffa27fffff, 276 table(s)
xc_dom_alloc_segment:   page tables  : 0xffffffffa25ca000 -> 0xffffffffa26e1000  (pfn 0x225ca + 0x117 pages)
xc_dom_pfn_to_ptr: domU mapping: pfn 0x225ca+0x117 at 0x7f097d7a8000
xc_dom_alloc_page   :   boot stack   : 0xffffffffa26e1000 (pfn 0x226e1)
xc_dom_build_image  : virt_alloc_end : 0xffffffffa26e2000
xc_dom_build_image  : virt_pgtab_end : 0xffffffffa2800000

So the physical memory and virtual (using __START_KERNEL_map addresses)
layout looks as so:

  phys                             __ka
/------------\                   /-------------------\
| 0          | empty             | 0xffffffff80000000|
| ..         |                   | ..                |
| 16MB       | <= kernel starts  | 0xffffffff81000000|
| ..         |                   |                   |
| 30MB       | <= kernel ends => | 0xffffffff81e43000|
| ..         |  & ramdisk starts | ..                |
| 293MB      | <= ramdisk ends=> | 0xffffffff925c7000|
| ..         |  & P2M starts     | ..                |
| ..         |                   | ..                |
| 549MB      | <= P2M ends    => | 0xffffffffa25c7000|
| ..         | start_info        | 0xffffffffa25c7000|
| ..         | xenstore          | 0xffffffffa25c8000|
| ..         | cosole            | 0xffffffffa25c9000|
| 549MB      | <= page tables => | 0xffffffffa25ca000|
| ..         |                   |                   |
| 550MB      | <= PGT end     => | 0xffffffffa26e1000|
| ..         | boot stack        |                   |
\------------/                   \-------------------/

As can be seen, the ramdisk, P2M and pagetables are taking
a bit of __ka addresses space. Which is a problem since the
MODULES_VADDR starts at 0xffffffffa0000000 - and P2M sits
right in there! This results during bootup with the inability to
load modules, with this error:

------------[ cut here ]------------
WARNING: at /home/konrad/ssd/linux/mm/vmalloc.c:106 vmap_page_range_noflush+0x2d9/0x370()
Call Trace:
 [<ffffffff810719fa>] warn_slowpath_common+0x7a/0xb0
 [<ffffffff81030279>] ? __raw_callee_save_xen_pmd_val+0x11/0x1e
 [<ffffffff81071a45>] warn_slowpath_null+0x15/0x20
 [<ffffffff81130b89>] vmap_page_range_noflush+0x2d9/0x370
 [<ffffffff81130c4d>] map_vm_area+0x2d/0x50
 [<ffffffff811326d0>] __vmalloc_node_range+0x160/0x250
 [<ffffffff810c5369>] ? module_alloc_update_bounds+0x19/0x80
 [<ffffffff810c6186>] ? load_module+0x66/0x19c0
 [<ffffffff8105cadc>] module_alloc+0x5c/0x60
 [<ffffffff810c5369>] ? module_alloc_update_bounds+0x19/0x80
 [<ffffffff810c5369>] module_alloc_update_bounds+0x19/0x80
 [<ffffffff810c70c3>] load_module+0xfa3/0x19c0
 [<ffffffff812491f6>] ? security_file_permission+0x86/0x90
 [<ffffffff810c7b3a>] sys_init_module+0x5a/0x220
 [<ffffffff815ce339>] system_call_fastpath+0x16/0x1b
---[ end trace fd8f7704fdea0291 ]---
vmalloc: allocation failure, allocated 16384 of 20480 bytes
modprobe: page allocation failure: order:0, mode:0xd2

Since the __va and __ka are 1:1 up to MODULES_VADDR and
cleanup_highmap rids __ka of the ramdisk mapping, what
we want to do is similar - get rid of the P2M in the __ka
address space. There are two ways of fixing this:

 1) All P2M lookups instead of using the __ka address would
    use the __va address. This means we can safely erase from
    __ka space the PMD pointers that point to the PFNs for
    P2M array and be OK.
 2). Allocate a new array, copy the existing P2M into it,
    revector the P2M tree to use that, and return the old
    P2M to the memory allocate. This has the advantage that
    it sets the stage for using XEN_ELF_NOTE_INIT_P2M
    feature. That feature allows us to set the exact virtual
    address space we want for the P2M - and allows us to
    boot as initial domain on large machines.

So we pick option 2).

This patch only lays the groundwork in the P2M code. The patch
that modifies the MMU is called "xen/mmu: Copy and revector the P2M tree."

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-08-23 11:52:13 -04:00
Konrad Rzeszutek Wilk
488f046df9 xen/mmu: Recycle the Xen provided L4, L3, and L2 pages
As we are not using them. We end up only using the L1 pagetables
and grafting those to our page-tables.

[v1: Per Stefano's suggestion squashed two commits]
[v2: Per Stefano's suggestion simplified loop]
[v3: Fix smatch warnings]
[v4: Add more comments]
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-08-23 11:52:12 -04:00
Konrad Rzeszutek Wilk
caaf9ecf16 xen/mmu: For 64-bit do not call xen_map_identity_early
B/c we do not need it. During the startup the Xen provides
us with all the initial memory mapped that we need to function.

The initial memory mapped is up to the bootstack, which means
we can reference using __ka up to 4.f):

(from xen/interface/xen.h):

 4. This the order of bootstrap elements in the initial virtual region:
   a. relocated kernel image
   b. initial ram disk              [mod_start, mod_len]
   c. list of allocated page frames [mfn_list, nr_pages]
   d. start_info_t structure        [register ESI (x86)]
   e. bootstrap page tables         [pt_base, CR3 (x86)]
   f. bootstrap stack               [register ESP (x86)]

(initial ram disk may be ommitted).

[v1: More comments in git commit]
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-08-23 11:52:07 -04:00
Konrad Rzeszutek Wilk
ae895ed783 xen/mmu: use copy_page instead of memcpy.
After all, this is what it is there for.

Acked-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-08-23 11:33:30 -04:00
Konrad Rzeszutek Wilk
4fac153a7a xen/mmu: Provide comments describing the _ka and _va aliasing issue
Which is that the level2_kernel_pgt (__ka virtual addresses)
and level2_ident_pgt (__va virtual address) contain the same
PMD entries. So if you modify a PTE in __ka, it will be reflected
in __va (and vice-versa).

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-08-23 11:33:29 -04:00
Konrad Rzeszutek Wilk
3699aad047 xen/mmu: The xen_setup_kernel_pagetable doesn't need to return anything.
We don't need to return the new PGD - as we do not use it.

Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-08-23 11:33:28 -04:00
Konrad Rzeszutek Wilk
51faaf2b0d Revert "xen/x86: Workaround 64-bit hypervisor and 32-bit initial domain." and "xen/x86: Use memblock_reserve for sensitive areas."
This reverts commit 806c312e50 and
commit 59b294403e.

And also documents setup.c and why we want to do it that way, which
is that we tried to make the the memblock_reserve more selective so
that it would be clear what region is reserved. Sadly we ran
in the problem wherein on a 64-bit hypervisor with a 32-bit
initial domain, the pt_base has the cr3 value which is not
neccessarily where the pagetable starts! As Jan put it: "
Actually, the adjustment turns out to be correct: The page
tables for a 32-on-64 dom0 get allocated in the order "first L1",
"first L2", "first L3", so the offset to the page table base is
indeed 2. When reading xen/include/public/xen.h's comment
very strictly, this is not a violation (since there nothing is said
that the first thing in the page table space is pointed to by
pt_base; I admit that this seems to be implied though, namely
do I think that it is implied that the page table space is the
range [pt_base, pt_base + nt_pt_frames), whereas that
range here indeed is [pt_base - 2, pt_base - 2 + nt_pt_frames),
which - without a priori knowledge - the kernel would have
difficulty to figure out)." - so lets just fall back to the
easy way and reserve the whole region.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-08-23 11:33:27 -04:00
Konrad Rzeszutek Wilk
806c312e50 xen/x86: Workaround 64-bit hypervisor and 32-bit initial domain.
If a 64-bit hypervisor is booted with a 32-bit initial domain,
the hypervisor deals with the initial domain as "compat" and
does some extra adjustments (like pagetables are 4 bytes instead
of 8). It also adjusts the xen_start_info->pt_base incorrectly.

When booted with a 32-bit hypervisor (32-bit initial domain):
..
(XEN)  Start info:    cf831000->cf83147c
(XEN)  Page tables:   cf832000->cf8b5000
..
[    0.000000] PT: cf832000 (f832000)
[    0.000000] Reserving PT: f832000->f8b5000

And with a 64-bit hypervisor:
(XEN)  Start info:    00000000cf831000->00000000cf8314b4
(XEN)  Page tables:   00000000cf832000->00000000cf8b6000

[    0.000000] PT: cf834000 (f834000)
[    0.000000] Reserving PT: f834000->f8b8000

To deal with this, we keep keep track of the highest physical
address we have reserved via memblock_reserve. If that address
does not overlap with pt_base, we have a gap which we reserve.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-08-21 14:45:33 -04:00
Konrad Rzeszutek Wilk
59b294403e xen/x86: Use memblock_reserve for sensitive areas.
instead of a big memblock_reserve. This way we can be more
selective in freeing regions (and it also makes it easier
to understand where is what).

[v1: Move the auto_translate_physmap to proper line]
[v2: Per Stefano suggestion add more comments]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-08-21 14:44:50 -04:00
Konrad Rzeszutek Wilk
a3118beb6a xen/p2m: Fix the comment describing the P2M tree.
It mixed up the p2m_mid_missing with p2m_missing. Also
remove some extra spaces.

Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-08-21 14:44:34 -04:00
Linus Torvalds
069915b946 Five bug-fixes:
- When booting as PVHVM we would try to use PV console - but would not validate
    the parameters causing us to crash during restore b/c we re-use the wrong event
    channel.
  - When booting on machines with SR-IOV PCI bridge we didn't check for the bridge
    and tried to use it.
  - Under AMD machines would advertise the APERFMPERF resulting in needless amount
    of MSRs from the guest.
  - A global value (xen_released_pages) was not subtracted at bootup when pages
    were added back in. This resulted in the balloon worker having the wrong
    account of how many pages were truly released.
  - Fix dead-lock when xen-blkfront is run in the same domain as xen-blkback.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1.4.12 (GNU/Linux)
 
 iQEcBAABAgAGBQJP2kcmAAoJEFjIrFwIi8fJXLcH/0a2m6KMcyjc4WaCHspAEFDL
 9B055QUFDEOlH55wE2QeED/8D+0HUbTYnQBycH126XLKzLfRv1fsrKFKDSA/SWW2
 Mh8N316UrY5Wc3KMdxXdCXJCDqDs7VhARTv6JdlUqUlH9oLRYE6CMRO8MujT0iwd
 r+uEnNuW0udMFt8x9SnJW7pEaq7u2N5koEGdWEzZhfoumDaCRxm5OKAKXZ0DZlEZ
 /BPjTW/N+Pf4u+bJZY+wQq41y4zGMqu7TDo/hOpuGZxeqtVnCE9trBbuGLnp4K+W
 n4TfZZs9Y1kovSMj6qTeB0aP0F77tqHyXPb1oPKxm2kWfqT2dFtIRpuLtXYSC+o=
 =cQl2
 -----END PGP SIGNATURE-----

Merge tag 'stable/for-linus-3.5-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen

Pull five Xen bug-fixes from Konrad Rzeszutek Wilk:

 - When booting as PVHVM we would try to use PV console - but would not validate
   the parameters causing us to crash during restore b/c we re-use the wrong event
   channel.
 - When booting on machines with SR-IOV PCI bridge we didn't check for the bridge
   and tried to use it.
 - Under AMD machines would advertise the APERFMPERF resulting in needless amount
   of MSRs from the guest.
 - A global value (xen_released_pages) was not subtracted at bootup when pages
   were added back in. This resulted in the balloon worker having the wrong
   account of how many pages were truly released.
 - Fix dead-lock when xen-blkfront is run in the same domain as xen-blkback.

* tag 'stable/for-linus-3.5-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen: mark local pages as FOREIGN in the m2p_override
  xen/setup: filter APERFMPERF cpuid feature out
  xen/balloon: Subtract from xen_released_pages the count that is populated.
  xen/pci: Check for PCI bridge before using it.
  xen/events: Add WARN_ON when quick lookup found invalid type.
  xen/hvc: Check HVM_PARAM_CONSOLE_[EVTCHN|PFN] for correctness.
  xen/hvc: Fix error cases around HVM_PARAM_CONSOLE_PFN
  xen/hvc: Collapse error logic.
2012-06-15 17:17:15 -07:00
Stefano Stabellini
b9e0d95c04 xen: mark local pages as FOREIGN in the m2p_override
When the frontend and the backend reside on the same domain, even if we
add pages to the m2p_override, these pages will never be returned by
mfn_to_pfn because the check "get_phys_to_machine(pfn) != mfn" will
always fail, so the pfn of the frontend will be returned instead
(resulting in a deadlock because the frontend pages are already locked).

INFO: task qemu-system-i38:1085 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
qemu-system-i38 D ffff8800cfc137c0     0  1085      1 0x00000000
 ffff8800c47ed898 0000000000000282 ffff8800be4596b0 00000000000137c0
 ffff8800c47edfd8 ffff8800c47ec010 00000000000137c0 00000000000137c0
 ffff8800c47edfd8 00000000000137c0 ffffffff82213020 ffff8800be4596b0
Call Trace:
 [<ffffffff81101ee0>] ? __lock_page+0x70/0x70
 [<ffffffff81a0fdd9>] schedule+0x29/0x70
 [<ffffffff81a0fe80>] io_schedule+0x60/0x80
 [<ffffffff81101eee>] sleep_on_page+0xe/0x20
 [<ffffffff81a0e1ca>] __wait_on_bit_lock+0x5a/0xc0
 [<ffffffff81101ed7>] __lock_page+0x67/0x70
 [<ffffffff8106f750>] ? autoremove_wake_function+0x40/0x40
 [<ffffffff811867e6>] ? bio_add_page+0x36/0x40
 [<ffffffff8110b692>] set_page_dirty_lock+0x52/0x60
 [<ffffffff81186021>] bio_set_pages_dirty+0x51/0x70
 [<ffffffff8118c6b4>] do_blockdev_direct_IO+0xb24/0xeb0
 [<ffffffff811e71a0>] ? ext3_get_blocks_handle+0xe00/0xe00
 [<ffffffff8118ca95>] __blockdev_direct_IO+0x55/0x60
 [<ffffffff811e71a0>] ? ext3_get_blocks_handle+0xe00/0xe00
 [<ffffffff811e91c8>] ext3_direct_IO+0xf8/0x390
 [<ffffffff811e71a0>] ? ext3_get_blocks_handle+0xe00/0xe00
 [<ffffffff81004b60>] ? xen_mc_flush+0xb0/0x1b0
 [<ffffffff81104027>] generic_file_aio_read+0x737/0x780
 [<ffffffff813bedeb>] ? gnttab_map_refs+0x15b/0x1e0
 [<ffffffff811038f0>] ? find_get_pages+0x150/0x150
 [<ffffffff8119736c>] aio_rw_vect_retry+0x7c/0x1d0
 [<ffffffff811972f0>] ? lookup_ioctx+0x90/0x90
 [<ffffffff81198856>] aio_run_iocb+0x66/0x1a0
 [<ffffffff811998b8>] do_io_submit+0x708/0xb90
 [<ffffffff81199d50>] sys_io_submit+0x10/0x20
 [<ffffffff81a18d69>] system_call_fastpath+0x16/0x1b

The explanation is in the comment within the code:

We need to do this because the pages shared by the frontend
(xen-blkfront) can be already locked (lock_page, called by
do_read_cache_page); when the userspace backend tries to use them
with direct_IO, mfn_to_pfn returns the pfn of the frontend, so
do_blockdev_direct_IO is going to try to lock the same pages
again resulting in a deadlock.

A simplified call graph looks like this:

pygrub                          QEMU
-----------------------------------------------
do_read_cache_page              io_submit
  |                              |
lock_page                       ext3_direct_IO
                                 |
                                bio_add_page
                                 |
                                lock_page

Internally the xen-blkback uses m2p_add_override to swizzle (temporarily)
a 'struct page' to have a different MFN (so that it can point to another
guest). It also can easily find out whether another pfn corresponding
to the mfn exists in the m2p, and can set the FOREIGN bit
in the p2m, making sure that mfn_to_pfn returns the pfn of the backend.

This allows the backend to perform direct_IO on these pages, but as a
side effect prevents the frontend from using get_user_pages_fast on
them while they are being shared with the backend.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-06-14 14:03:41 -04:00
Andre Przywara
5e62625420 xen/setup: filter APERFMPERF cpuid feature out
Xen PV kernels allow access to the APERF/MPERF registers to read the
effective frequency. Access to the MSRs is however redirected to the
currently scheduled physical CPU, making consecutive read and
compares unreliable. In addition each rdmsr traps into the hypervisor.
So to avoid bogus readouts and expensive traps, disable the kernel
internal feature flag for APERF/MPERF if running under Xen.
This will
a) remove the aperfmperf flag from /proc/cpuinfo
b) not mislead the power scheduler (arch/x86/kernel/cpu/sched.c) to
   use the feature to improve scheduling (by default disabled)
c) not mislead the cpufreq driver to use the MSRs

This does not cover userland programs which access the MSRs via the
device file interface, but this will be addressed separately.

Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Cc: stable@vger.kernel.org # v3.0+
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-05-31 12:16:52 -04:00
Konrad Rzeszutek Wilk
1ab46fd319 x86, amd, xen: Avoid NULL pointer paravirt references
Stub out MSR methods that aren't actually needed.  This fixes a crash
as Xen Dom0 on AMD Trinity systems.  A bigger patch should be added to
remove the paravirt machinery completely for the methods which
apparently have no users!

Reported-by: Andre Przywara <andre.przywara@amd.com>
Link: http://lkml.kernel.org/r/20120530222356.GA28417@andromeda.dapyr.net
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: <stable@vger.kernel.org>
2012-05-30 16:15:02 -07:00
Konrad Rzeszutek Wilk
58b7b53a36 xen/balloon: Subtract from xen_released_pages the count that is populated.
We did not take into account that xen_released_pages would be
used outside the initial E820 parsing code. As such we would
did not subtract from xen_released_pages the count of pages
that we had populated back (instead we just did a simple
extra_pages = released - populated).

The balloon driver uses xen_released_pages to set the initial
current_pages count.  If this is wrong (too low) then when a new
(higher) target is set, the balloon driver will request too many pages
from Xen."

This fixes errors such as:

(XEN) memory.c:133:d0 Could not allocate order=0 extent: id=0 memflags=0 (51 of 512)
during bootup and
free_memory            : 0

where the free_memory should be 128.

Acked-by: David Vrabel <david.vrabel@citrix.com>
[v1: Per David's review made the git commit better]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-05-30 10:16:37 -04:00
Linus Torvalds
b5f4035adf Features:
* Extend the APIC ops implementation and add IRQ_WORKER vector support so that 'perf' can work properly.
  * Fix self-ballooning code, and balloon logic when booting as initial domain.
  * Move array printing code to generic debugfs
  * Support XenBus domains.
  * Lazily free grants when a domain is dead/non-existent.
  * In M2P code use batching calls
 Bug-fixes:
  * Fix NULL dereference in allocation failure path (hvc_xen)
  * Fix unbinding of IRQ_WORKER vector during vCPU hot-unplug
  * Fix HVM guest resume - we would leak an PIRQ value instead of reusing the existing one.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1.4.11 (GNU/Linux)
 
 iQEcBAABAgAGBQJPu9MpAAoJEFjIrFwIi8fJaNQH/RylThiO+O+LBpPrO8VRUw+2
 /Io98T7ZK2ggoUeaJx0C8irM0JMFAkxGMcfX3w9fwNt/BTec4s++4JhbN1jYN0da
 6a0PqINo+M8y73So6CBfuJDCunaRLGKVG/ibIO3Y3WAff51/H+DMvO7uYYDAE0aA
 mikyOxnaty0DiG5i4JGDHGmCzDASfK/jgGccZ03m6522mDx5ZIbTzZWONLfz8dqT
 rbxnn9vrNLgEYWuzyLMwW0GymToUtt01xBQvwJLAbhn8lr1WBRBLpxXA+5iYNQrn
 Ri25G7keYJhG4uwZfaHnR+4HTrmhlGzK1Z96dkqpGUaeIcdyWmPMp22VtBBiwG8=
 =uyRr
 -----END PGP SIGNATURE-----

Merge tag 'stable/for-linus-3.5-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen

Pull Xen updates from Konrad Rzeszutek Wilk:
 "Features:
   * Extend the APIC ops implementation and add IRQ_WORKER vector
     support so that 'perf' can work properly.
   * Fix self-ballooning code, and balloon logic when booting as initial
     domain.
   * Move array printing code to generic debugfs
   * Support XenBus domains.
   * Lazily free grants when a domain is dead/non-existent.
   * In M2P code use batching calls
  Bug-fixes:
   * Fix NULL dereference in allocation failure path (hvc_xen)
   * Fix unbinding of IRQ_WORKER vector during vCPU hot-unplug
   * Fix HVM guest resume - we would leak an PIRQ value instead of
     reusing the existing one."

Fix up add-add onflicts in arch/x86/xen/enlighten.c due to addition of
apic ipi interface next to the new apic_id functions.

* tag 'stable/for-linus-3.5-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen: do not map the same GSI twice in PVHVM guests.
  hvc_xen: NULL dereference on allocation failure
  xen: Add selfballoning memory reservation tunable.
  xenbus: Add support for xenbus backend in stub domain
  xen/smp: unbind irqworkX when unplugging vCPUs.
  xen: enter/exit lazy_mmu_mode around m2p_override calls
  xen/acpi/sleep: Enable ACPI sleep via the __acpi_os_prepare_sleep
  xen: implement IRQ_WORK_VECTOR handler
  xen: implement apic ipi interface
  xen/setup: update VA mapping when releasing memory during setup
  xen/setup: Combine the two hypercall functions - since they are quite similar.
  xen/setup: Populate freed MFNs from non-RAM E820 entries and gaps to E820 RAM
  xen/setup: Only print "Freeing XXX-YYY pfn range: Z pages freed" if Z > 0
  xen/gnttab: add deferred freeing logic
  debugfs: Add support to print u32 array in debugfs
  xen/p2m: An early bootup variant of set_phys_to_machine
  xen/p2m: Collapse early_alloc_p2m_middle redundant checks.
  xen/p2m: Allow alloc_p2m_middle to call reserve_brk depending on argument
  xen/p2m: Move code around to allow for better re-usage.
2012-05-24 16:02:08 -07:00
Linus Torvalds
269af9a1a0 Merge branch 'x86-extable-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull exception table generation updates from Ingo Molnar:
 "The biggest change here is to allow the build-time sorting of the
  exception table, to speed up booting.  This is achieved by the
  architecture enabling BUILDTIME_EXTABLE_SORT.  This option is enabled
  for x86 and MIPS currently.

  On x86 a number of fixes and changes were needed to allow build-time
  sorting of the exception table, in particular a relocation invariant
  exception table format was needed.  This required the abstracting out
  of exception table protocol and the removal of 20 years of accumulated
  assumptions about the x86 exception table format.

  While at it, this tree also cleans up various other aspects of
  exception handling, such as early(er) exception handling for
  rdmsr_safe() et al.

  All in one, as the result of these changes the x86 exception code is
  now pretty nice and modern.  As an added bonus any regressions in this
  code will be early and violent crashes, so if you see any of those,
  you'll know whom to blame!"

Fix up trivial conflicts in arch/{mips,x86}/Kconfig files due to nearby
modifications of other core architecture options.

* 'x86-extable-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (35 commits)
  Revert "x86, extable: Disable presorted exception table for now"
  scripts/sortextable: Handle relative entries, and other cleanups
  x86, extable: Switch to relative exception table entries
  x86, extable: Disable presorted exception table for now
  x86, extable: Add _ASM_EXTABLE_EX() macro
  x86, extable: Remove open-coded exception table entries in arch/x86/ia32/ia32entry.S
  x86, extable: Remove open-coded exception table entries in arch/x86/include/asm/xsave.h
  x86, extable: Remove open-coded exception table entries in arch/x86/include/asm/kvm_host.h
  x86, extable: Remove the now-unused __ASM_EX_SEC macros
  x86, extable: Remove open-coded exception table entries in arch/x86/xen/xen-asm_32.S
  x86, extable: Remove open-coded exception table entries in arch/x86/um/checksum_32.S
  x86, extable: Remove open-coded exception table entries in arch/x86/lib/usercopy_32.c
  x86, extable: Remove open-coded exception table entries in arch/x86/lib/putuser.S
  x86, extable: Remove open-coded exception table entries in arch/x86/lib/getuser.S
  x86, extable: Remove open-coded exception table entries in arch/x86/lib/csum-copy_64.S
  x86, extable: Remove open-coded exception table entries in arch/x86/lib/copy_user_nocache_64.S
  x86, extable: Remove open-coded exception table entries in arch/x86/lib/copy_user_64.S
  x86, extable: Remove open-coded exception table entries in arch/x86/lib/checksum_32.S
  x86, extable: Remove open-coded exception table entries in arch/x86/kernel/test_rodata.c
  x86, extable: Remove open-coded exception table entries in arch/x86/kernel/entry_64.S
  ...
2012-05-23 10:44:35 -07:00
Linus Torvalds
f08b9c2f8a Merge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86/apic changes from Ingo Molnar:
 "Most of the changes are about helping virtualized guest kernels
  achieve better performance."

Fix up trivial conflicts with the iommu updates to arch/x86/kernel/apic/io_apic.c

* 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/apic: Implement EIO micro-optimization
  x86/apic: Add apic->eoi_write() callback
  x86/apic: Use symbolic APIC_EOI_ACK
  x86/apic: Fix typo EIO_ACK -> EOI_ACK and document it
  x86/xen/apic: Add missing #include <xen/xen.h>
  x86/apic: Only compile local function if used with !CONFIG_GENERIC_PENDING_IRQ
  x86/apic: Fix UP boot crash
  x86: Conditionally update time when ack-ing pending irqs
  xen/apic: implement io apic read with hypercall
  Revert "xen/x86: Workaround 'x86/ioapic: Add register level checks to detect bogus io-apic entries'"
  xen/x86: Implement x86_apic_ops
  x86/apic: Replace io_apic_ops with x86_io_apic_ops.
2012-05-22 18:38:11 -07:00
Linus Torvalds
bf67f3a5c4 Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull smp hotplug cleanups from Thomas Gleixner:
 "This series is merily a cleanup of code copied around in arch/* and
  not changing any of the real cpu hotplug horrors yet.  I wish I'd had
  something more substantial for 3.5, but I underestimated the lurking
  horror..."

Fix up trivial conflicts in arch/{arm,sparc,x86}/Kconfig and
arch/sparc/include/asm/thread_info_32.h

* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (79 commits)
  um: Remove leftover declaration of alloc_task_struct_node()
  task_allocator: Use config switches instead of magic defines
  sparc: Use common threadinfo allocator
  score: Use common threadinfo allocator
  sh-use-common-threadinfo-allocator
  mn10300: Use common threadinfo allocator
  powerpc: Use common threadinfo allocator
  mips: Use common threadinfo allocator
  hexagon: Use common threadinfo allocator
  m32r: Use common threadinfo allocator
  frv: Use common threadinfo allocator
  cris: Use common threadinfo allocator
  x86: Use common threadinfo allocator
  c6x: Use common threadinfo allocator
  fork: Provide kmemcache based thread_info allocator
  tile: Use common threadinfo allocator
  fork: Provide weak arch_release_[task_struct|thread_info] functions
  fork: Move thread info gfp flags to header
  fork: Remove the weak insanity
  sh: Remove cpu_idle_wait()
  ...
2012-05-21 19:43:57 -07:00
Konrad Rzeszutek Wilk
2f1bd67d54 xen/smp: unbind irqworkX when unplugging vCPUs.
The git commit  1ff2b0c303
"xen: implement IRQ_WORK_VECTOR handler" added the functionality
to have a per-cpu "irqworkX" for the IPI APIC functionality.
However it missed the unbind when a vCPU is unplugged resulting
in an orphaned per-cpu interrupt line for unplugged vCPU:

  30:        216          0   xen-dyn-event     hvc_console
  31:        810          4   xen-dyn-event     eth0
  32:         29          0   xen-dyn-event     blkif
- 36:          0          0  xen-percpu-ipi       irqwork2
- 37:        287          0   xen-dyn-event     xenbus
+ 36:        287          0   xen-dyn-event     xenbus
 NMI:          0          0   Non-maskable interrupts
 LOC:          0          0   Local timer interrupts
 SPU:          0          0   Spurious interrupts

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-05-21 09:26:04 -04:00
Ingo Molnar
87e4baacae x86/xen/apic: Add missing #include <xen/xen.h>
This file depends on <xen/xen.h>, but the dependency was hidden due
to: <asm/acpi.h> -> <asm/trampoline.h> -> <asm/io.h> -> <xen/xen.h>

With the removal of <asm/trampoline.h>, this exposed the missing

Cc: Len Brown <lenb@kernel.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/n/tip-7ccybvue6mw6wje3uxzzcglj@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-05-18 09:34:45 +02:00
Thomas Gleixner
67ba5293f7 Merge branch 'smp/threadalloc' into smp/hotplug
Reason: Pull in the separate branch which was created so arch/tile can
base further work on it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-05-08 14:07:48 +02:00
Konrad Rzeszutek Wilk
4b3451ad13 Merge branch 'stable/autoballoon.v5.2' into stable/for-linus-3.5
* stable/autoballoon.v5.2:
  xen/setup: update VA mapping when releasing memory during setup
  xen/setup: Combine the two hypercall functions - since they are quite similar.
  xen/setup: Populate freed MFNs from non-RAM E820 entries and gaps to E820 RAM
  xen/setup: Only print "Freeing XXX-YYY pfn range: Z pages freed" if Z > 0
  xen/p2m: An early bootup variant of set_phys_to_machine
  xen/p2m: Collapse early_alloc_p2m_middle redundant checks.
  xen/p2m: Allow alloc_p2m_middle to call reserve_brk depending on argument
  xen/p2m: Move code around to allow for better re-usage.
2012-05-07 15:33:27 -04:00
Konrad Rzeszutek Wilk
211063dc15 xen/acpi/sleep: Enable ACPI sleep via the __acpi_os_prepare_sleep
Provide the registration callback to call in the Xen's
ACPI sleep functionality. This means that during S3/S5
we make a hypercall XENPF_enter_acpi_sleep with the
proper PM1A/PM1B registers.

Based of Ke Yu's <ke.yu@intel.com> initial idea.
[ From http://xenbits.xensource.com/linux-2.6.18-xen.hg
change c68699484a65 ]

[v1: Added Copyright and license]
[v2: Added check if PM1A/B the 16-bits MSB contain something. The spec
     only uses 16-bits but might have more in future]
Signed-off-by: Liang Tang <liang.tang@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-05-07 15:33:18 -04:00
Lin Ming
1ff2b0c303 xen: implement IRQ_WORK_VECTOR handler
Signed-off-by: Lin Ming <mlin@ss.pku.edu.cn>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-05-07 15:33:17 -04:00
Ben Guthro
f447d56d36 xen: implement apic ipi interface
Map native ipi vector to xen vector.
Implement apic ipi interface with xen_send_IPI_one.

Tested-by: Steven Noonan <steven@uplinklabs.net>
Signed-off-by: Ben Guthro <ben@guthro.net>
Signed-off-by: Lin Ming <mlin@ss.pku.edu.cn>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-05-07 15:33:15 -04:00
David Vrabel
83d51ab473 xen/setup: update VA mapping when releasing memory during setup
In xen_memory_setup(), if a page that is being released has a VA
mapping this must also be updated.  Otherwise, the page will be not
released completely -- it will still be referenced in Xen and won't be
freed util the mapping is removed and this prevents it from being
reallocated at a different PFN.

This was already being done for the ISA memory region in
xen_ident_map_ISA() but on many systems this was omitting a few pages
as many systems marked a few pages below the ISA memory region as
reserved in the e820 map.

This fixes errors such as:

(XEN) page_alloc.c:1148:d0 Over-allocation for domain 0: 2097153 > 2097152
(XEN) memory.c:133:d0 Could not allocate order=0 extent: id=0 memflags=0 (0 of 17)

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-05-07 15:32:24 -04:00
Konrad Rzeszutek Wilk
96dc08b35c xen/setup: Combine the two hypercall functions - since they are quite similar.
They use the same set of arguments, so it is just the matter
of using the proper hypercall.

Acked-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-05-07 15:31:47 -04:00
Konrad Rzeszutek Wilk
2e2fb75475 xen/setup: Populate freed MFNs from non-RAM E820 entries and gaps to E820 RAM
When the Xen hypervisor boots a PV kernel it hands it two pieces
of information: nr_pages and a made up E820 entry.

The nr_pages value defines the range from zero to nr_pages of PFNs
which have a valid Machine Frame Number (MFN) underneath it. The
E820 mirrors that (with the VGA hole):
BIOS-provided physical RAM map:
 Xen: 0000000000000000 - 00000000000a0000 (usable)
 Xen: 00000000000a0000 - 0000000000100000 (reserved)
 Xen: 0000000000100000 - 0000000080800000 (usable)

The fun comes when a PV guest that is run with a machine E820 - that
can either be the initial domain or a PCI PV guest, where the E820
looks like the normal thing:

BIOS-provided physical RAM map:
 Xen: 0000000000000000 - 000000000009e000 (usable)
 Xen: 000000000009ec00 - 0000000000100000 (reserved)
 Xen: 0000000000100000 - 0000000020000000 (usable)
 Xen: 0000000020000000 - 0000000020200000 (reserved)
 Xen: 0000000020200000 - 0000000040000000 (usable)
 Xen: 0000000040000000 - 0000000040200000 (reserved)
 Xen: 0000000040200000 - 00000000bad80000 (usable)
 Xen: 00000000bad80000 - 00000000badc9000 (ACPI NVS)
..
With that overlaying the nr_pages directly on the E820 does not
work as there are gaps and non-RAM regions that won't be used
by the memory allocator. The 'xen_release_chunk' helps with that
by punching holes in the P2M (PFN to MFN lookup tree) for those
regions and tells us that:

Freeing  20000-20200 pfn range: 512 pages freed
Freeing  40000-40200 pfn range: 512 pages freed
Freeing  bad80-badf4 pfn range: 116 pages freed
Freeing  badf6-bae7f pfn range: 137 pages freed
Freeing  bb000-100000 pfn range: 282624 pages freed
Released 283999 pages of unused memory

Those 283999 pages are subtracted from the nr_pages and are returned
to the hypervisor. The end result is that the initial domain
boots with 1GB less memory as the nr_pages has been subtracted by
the amount of pages residing within the PCI hole. It can balloon up
to that if desired using 'xl mem-set 0 8092', but the balloon driver
is not always compiled in for the initial domain.

This patch, implements the populate hypercall (XENMEM_populate_physmap)
which increases the the domain with the same amount of pages that
were released.

The other solution (that did not work) was to transplant the MFN in
the P2M tree - the ones that were going to be freed were put in
the E820_RAM regions past the nr_pages. But the modifications to the
M2P array (the other side of creating PTEs) were not carried away.
As the hypervisor is the only one capable of modifying that and the
only two hypercalls that would do this are: the update_va_mapping
(which won't work, as during initial bootup only PFNs up to nr_pages
are mapped in the guest) or via the populate hypercall.

The end result is that the kernel can now boot with the
nr_pages without having to subtract the 283999 pages.

On a 8GB machine, with various dom0_mem= parameters this is what we get:

no dom0_mem
-Memory: 6485264k/9435136k available (5817k kernel code, 1136060k absent, 1813812k reserved, 2899k data, 696k init)
+Memory: 7619036k/9435136k available (5817k kernel code, 1136060k absent, 680040k reserved, 2899k data, 696k init)

dom0_mem=3G
-Memory: 2616536k/9435136k available (5817k kernel code, 1136060k absent, 5682540k reserved, 2899k data, 696k init)
+Memory: 2703776k/9435136k available (5817k kernel code, 1136060k absent, 5595300k reserved, 2899k data, 696k init)

dom0_mem=max:3G
-Memory: 2696732k/4281724k available (5817k kernel code, 1136060k absent, 448932k reserved, 2899k data, 696k init)
+Memory: 2702204k/4281724k available (5817k kernel code, 1136060k absent, 443460k reserved, 2899k data, 696k init)

And the 'xm list' or 'xl list' now reflect what the dom0_mem=
argument is.

Acked-by: David Vrabel <david.vrabel@citrix.com>
[v2: Use populate hypercall]
[v3: Remove debug printks]
[v4: Simplify code]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-05-07 15:31:46 -04:00
Konrad Rzeszutek Wilk
ca1182387e xen/setup: Only print "Freeing XXX-YYY pfn range: Z pages freed" if Z > 0
Otherwise we can get these meaningless:
Freeing  bad80-badf4 pfn range: 0 pages freed

We also can do this for the summary ones - no point of printing
"Set 0 page(s) to 1-1 mapping"

Acked-by: David Vrabel <david.vrabel@citrix.com>
[v1: Extended to the summary printks]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-05-07 15:30:56 -04:00
David Vrabel
76a8df7b49 xen/pci: don't use PCI BIOS service for configuration space accesses
The accessing PCI configuration space with the PCI BIOS32 service does
not work in PV guests.

On systems without MMCONFIG or where the BIOS hasn't marked the
MMCONFIG region as reserved in the e820 map, the BIOS service is
probed (even though direct access is preferred) and this hangs.

CC: stable@kernel.org
Acked-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
[v1: Fixed compile error when CONFIG_PCI is not set]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-05-07 12:16:21 -04:00
Konrad Rzeszutek Wilk
b7e5ffe5d8 xen/pte: Fix crashes when trying to see non-existent PGD/PMD/PUD/PTEs
If I try to do "cat /sys/kernel/debug/kernel_page_tables"
I end up with:

BUG: unable to handle kernel paging request at ffffc7fffffff000
IP: [<ffffffff8106aa51>] ptdump_show+0x221/0x480
PGD 0
Oops: 0000 [#1] SMP
CPU 0
.. snip..
RAX: 0000000000000000 RBX: ffffc00000000fff RCX: 0000000000000000
RDX: 0000800000000000 RSI: 0000000000000000 RDI: ffffc7fffffff000

which is due to the fact we are trying to access a PFN that is not
accessible to us. The reason (at least in this case) was that
PGD[256] is set to __HYPERVISOR_VIRT_START which was setup (by the
hypervisor) to point to a read-only linear map of the MFN->PFN array.
During our parsing we would get the MFN (a valid one), try to look
it up in the MFN->PFN tree and find it invalid and return ~0 as PFN.
Then pte_mfn_to_pfn would happilly feed that in, attach the flags
and return it back to the caller. 'ptdump_show' bitshifts it and
gets and invalid value that it tries to dereference.

Instead of doing all of that, we detect the ~0 case and just
return !_PAGE_PRESENT.

This bug has been in existence .. at least until 2.6.37 (yikes!)

CC: stable@kernel.org
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-05-07 10:21:13 -04:00
Konrad Rzeszutek Wilk
558daa289a xen/apic: Return the APIC ID (and version) for CPU 0.
On x86_64 on AMD machines where the first APIC_ID is not zero, we get:

ACPI: LAPIC (acpi_id[0x01] lapic_id[0x10] enabled)
BIOS bug: APIC version is 0 for CPU 1/0x10, fixing up to 0x10
BIOS bug: APIC version mismatch, boot CPU: 0, CPU 1: version 10

which means that when the ACPI processor driver loads and
tries to parse the _Pxx states it fails to do as, as it
ends up calling acpi_get_cpuid which does this:

for_each_possible_cpu(i) {
        if (cpu_physical_id(i) == apic_id)
                return i;
}

And the bootup CPU, has not been found so it fails and returns -1
for the first CPU - which then subsequently in the loop that
"acpi_processor_get_info" does results in returning an error, which
means that "acpi_processor_add" failing and per_cpu(processor)
is never set (and is NULL).

That means that when xen-acpi-processor tries to load (much much
later on) and parse the P-states it gets -ENODEV from
acpi_processor_register_performance() (which tries to read
the per_cpu(processor)) and fails to parse the data.

Reported-by-and-Tested-by:  Stefan Bader <stefan.bader@canonical.com>
Suggested-by:  Boris Ostrovsky <boris.ostrovsky@amd.com>
[v2: Bit-shift APIC ID by 24 bits]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-05-07 10:18:47 -04:00
Lin Ming
ab6ec39a19 xen/apic: implement io apic read with hypercall
Implements xen_io_apic_read with hypercall, so it returns proper
IO-APIC information instead of fabricated one.

Fallback to return an emulated IO_APIC values if hypercall fails.

[v2: fallback to return an emulated IO_APIC values if hypercall fails]
Signed-off-by: Lin Ming <mlin@ss.pku.edu.cn>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-05-01 14:52:12 -04:00
Konrad Rzeszutek Wilk
27abd14bd9 Revert "xen/x86: Workaround 'x86/ioapic: Add register level checks to detect bogus io-apic entries'"
This reverts commit 2531d64b6f.

The two patches:
      x86/apic: Replace io_apic_ops with x86_io_apic_ops.
      xen/x86: Implement x86_apic_ops

take care of fixing it properly.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-05-01 14:50:55 -04:00
Konrad Rzeszutek Wilk
31b3c9d723 xen/x86: Implement x86_apic_ops
Or rather just implement one different function as opposed
to the native one : the read function.

We synthesize the values.

Acked-by:  Suresh Siddha <suresh.b.siddha@intel.com>
[v1: Rebased on top of tip/x86/urgent]
[v2: Return 0xfd instead of 0xff in the default case]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-05-01 14:50:33 -04:00
David Vrabel
7eb7ce4d2e xen: correctly check for pending events when restoring irq flags
In xen_restore_fl_direct(), xen_force_evtchn_callback() was being
called even if no events were pending.  This resulted in (depending on
workload) about a 100 times as many xen_version hypercalls as
necessary.

Fix this by correcting the sense of the conditional jump.

This seems to give a significant performance benefit for some
workloads.

There is some subtle tricksy "..since the check here is trying to
check both pending and masked in a single cmpw, but I think this is
correct. It will call check_events now only when the combined
mask+pending word is 0x0001 (aka unmasked, pending)." (Ian)

CC: stable@kernel.org
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-04-27 16:04:21 -04:00
Konrad Rzeszutek Wilk
cf405ae612 xen/smp: Fix crash when booting with ACPI hotplug CPUs.
When we boot on a machine that can hotplug CPUs and we
are using 'dom0_max_vcpus=X' on the Xen hypervisor line
to clip the amount of CPUs available to the initial domain,
we get this:

(XEN) Command line: com1=115200,8n1 dom0_mem=8G noreboot dom0_max_vcpus=8 sync_console mce_verbosity=verbose console=com1,vga loglvl=all guest_loglvl=all
.. snip..
DMI: Intel Corporation S2600CP/S2600CP, BIOS SE5C600.86B.99.99.x032.072520111118 07/25/2011
.. snip.
SMP: Allowing 64 CPUs, 32 hotplug CPUs
installing Xen timer for CPU 7
cpu 7 spinlock event irq 361
NMI watchdog: disabled (cpu7): hardware events not enabled
Brought up 8 CPUs
.. snip..
	[acpi processor finds the CPUs are not initialized and starts calling
	arch_register_cpu, which creates /sys/devices/system/cpu/cpu8/online]
CPU 8 got hotplugged
CPU 9 got hotplugged
CPU 10 got hotplugged
.. snip..
initcall 1_acpi_battery_init_async+0x0/0x1b returned 0 after 406 usecs
calling  erst_init+0x0/0x2bb @ 1

	[and the scheduler sticks newly started tasks on the new CPUs, but
	said CPUs cannot be initialized b/c the hypervisor has limited the
	amount of vCPUS to 8 - as per the dom0_max_vcpus=8 flag.
	The spinlock tries to kick the other CPU, but the structure for that
	is not initialized and we crash.]
BUG: unable to handle kernel paging request at fffffffffffffed8
IP: [<ffffffff81035289>] xen_spin_lock+0x29/0x60
PGD 180d067 PUD 180e067 PMD 0
Oops: 0002 [#1] SMP
CPU 7
Modules linked in:

Pid: 1, comm: swapper/0 Not tainted 3.4.0-rc2upstream-00001-gf5154e8 #1 Intel Corporation S2600CP/S2600CP
RIP: e030:[<ffffffff81035289>]  [<ffffffff81035289>] xen_spin_lock+0x29/0x60
RSP: e02b:ffff8801fb9b3a70  EFLAGS: 00010282

With this patch, we cap the amount of vCPUS that the initial domain
can run, to exactly what dom0_max_vcpus=X has specified.

In the future, if there is a hypercall that will allow a running
domain to expand past its initial set of vCPUS, this patch should
be re-evaluated.

CC: stable@kernel.org
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-04-26 22:07:21 -04:00
Konrad Rzeszutek Wilk
df88b2d96e xen/enlighten: Disable MWAIT_LEAF so that acpi-pad won't be loaded.
There are exactly four users of __monitor and __mwait:

 - cstate.c (which allows acpi_processor_ffh_cstate_enter to be called
   when the cpuidle API drivers are used. However patch
   "cpuidle: replace xen access to x86 pm_idle and default_idle"
   provides a mechanism to disable the cpuidle and use safe_halt.
 - smpboot (which allows mwait_play_dead to be called). However
   safe_halt is always used so we skip that.
 - intel_idle (same deal as above).
 - acpi_pad.c. This the one that we do not want to run as we
   will hit the below crash.

Why do we want to expose MWAIT_LEAF in the first place?
We want it for the xen-acpi-processor driver - which uploads
C-states to the hypervisor. If MWAIT_LEAF is set, the cstate.c
sets the proper address in the C-states so that the hypervisor
can benefit from using the MWAIT functionality. And that is
the sole reason for using it.

Without this patch, if a module performs mwait or monitor we
get this:

invalid opcode: 0000 [#1] SMP
CPU 2
.. snip..
Pid: 5036, comm: insmod Tainted: G           O 3.4.0-rc2upstream-dirty #2 Intel Corporation S2600CP/S2600CP
RIP: e030:[<ffffffffa000a017>]  [<ffffffffa000a017>] mwait_check_init+0x17/0x1000 [mwait_check]
RSP: e02b:ffff8801c298bf18  EFLAGS: 00010282
RAX: ffff8801c298a010 RBX: ffffffffa03b2000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff8801c29800d8 RDI: ffff8801ff097200
RBP: ffff8801c298bf18 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
R13: ffffffffa000a000 R14: 0000005148db7294 R15: 0000000000000003
FS:  00007fbb364f2700(0000) GS:ffff8801ff08c000(0000) knlGS:0000000000000000
CS:  e033 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 000000000179f038 CR3: 00000001c9469000 CR4: 0000000000002660
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process insmod (pid: 5036, threadinfo ffff8801c298a000, task ffff8801c29cd7e0)
Stack:
 ffff8801c298bf48 ffffffff81002124 ffffffffa03b2000 00000000000081fd
 000000000178f010 000000000178f030 ffff8801c298bf78 ffffffff810c41e6
 00007fff3fb30db9 00007fff3fb30db9 00000000000081fd 0000000000010000
Call Trace:
 [<ffffffff81002124>] do_one_initcall+0x124/0x170
 [<ffffffff810c41e6>] sys_init_module+0xc6/0x220
 [<ffffffff815b15b9>] system_call_fastpath+0x16/0x1b
Code: <0f> 01 c8 31 c0 0f 01 c9 c9 c3 00 00 00 00 00 00 00 00 00 00 00 00
RIP  [<ffffffffa000a017>] mwait_check_init+0x17/0x1000 [mwait_check]
 RSP <ffff8801c298bf18>
---[ end trace 16582fc8a3d1e29a ]---
Kernel panic - not syncing: Fatal exception

With this module (which is what acpi_pad.c would hit):

MODULE_AUTHOR("Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>");
MODULE_DESCRIPTION("mwait_check_and_back");
MODULE_LICENSE("GPL");
MODULE_VERSION();

static int __init mwait_check_init(void)
{
	__monitor((void *)&current_thread_info()->flags, 0, 0);
	__mwait(0, 0);
	return 0;
}
static void __exit mwait_check_exit(void)
{
}
module_init(mwait_check_init);
module_exit(mwait_check_exit);

Reported-by: Liu, Jinsong <jinsong.liu@intel.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-04-26 17:46:20 -04:00
Thomas Gleixner
7eb43a6d23 x86: Use generic idle thread allocation
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/20120420124557.246929343@linutronix.de
2012-04-26 12:06:10 +02:00
Thomas Gleixner
5cdaf1834f x86: Add task_struct argument to smp_ops.cpu_up
Preparatory patch to use the generic idle thread allocation.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/20120420124557.176604405@linutronix.de
2012-04-26 12:06:10 +02:00
H. Peter Anvin
8f6380b9ec x86, extable: Remove open-coded exception table entries in arch/x86/xen/xen-asm_32.S
Remove open-coded exception table entries in arch/x86/xen/xen-asm_32.S,
and replace them with _ASM_EXTABLE() macros; this will allow us to
change the format and type of the exception table entries.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Link: http://lkml.kernel.org/r/CA%2B55aFyijf43qSu3N9nWHEBwaGbb7T2Oq9A=9EyR=Jtyqfq_cQ@mail.gmail.com
2012-04-20 13:51:39 -07:00
Konrad Rzeszutek Wilk
3d81acb1cd Revert "xen/p2m: m2p_find_override: use list_for_each_entry_safe"
This reverts commit b960d6c43a.

If we have another thread (very likely) touched the list, we
end up hitting a problem "that the next element is wrong because
we should be able to cope with that. The problem is that the
next->next pointer would be set LIST_POISON1. " (Stefano's
comment on the patch).

Reverting for now.

Suggested-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-04-20 11:56:00 -04:00
Konrad Rzeszutek Wilk
681e4a5e13 Merge commit 'c104f1fa1ecf4ee0fc06e31b1f77630b2551be81' into stable/for-linus-3.4
* commit 'c104f1fa1ecf4ee0fc06e31b1f77630b2551be81': (14566 commits)
  cpufreq: OMAP: fix build errors: depends on ARCH_OMAP2PLUS
  sparc64: Eliminate obsolete __handle_softirq() function
  sparc64: Fix bootup crash on sun4v.
  kconfig: delete last traces of __enabled_ from autoconf.h
  Revert "kconfig: fix __enabled_ macros definition for invisible and un-selected symbols"
  kconfig: fix IS_ENABLED to not require all options to be defined
  irq_domain: fix type mismatch in debugfs output format
  staging: android: fix mem leaks in __persistent_ram_init()
  staging: vt6656: Don't leak memory in drivers/staging/vt6656/ioctl.c::private_ioctl()
  staging: iio: hmc5843: Fix crash in probe function.
  panic: fix stack dump print on direct call to panic()
  drivers/rtc/rtc-pl031.c: enable clock on all ST variants
  Revert "mm: vmscan: fix misused nr_reclaimed in shrink_mem_cgroup_zone()"
  hugetlb: fix race condition in hugetlb_fault()
  drivers/rtc/rtc-twl.c: use static register while reading time
  drivers/rtc/rtc-s3c.c: add placeholder for driver private data
  drivers/rtc/rtc-s3c.c: fix compilation error
  MAINTAINERS: add PCDP console maintainer
  memcg: do not open code accesses to res_counter members
  drivers/rtc/rtc-efi.c: fix section mismatch warning
  ...
2012-04-18 15:52:50 -04:00
Stefano Stabellini
b960d6c43a xen/p2m: m2p_find_override: use list_for_each_entry_safe
Use list_for_each_entry_safe and remove the spin_lock acquisition in
m2p_find_override.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-04-17 13:27:28 -04:00
Srivatsa Vaddagiri
9fe2a70153 debugfs: Add support to print u32 array in debugfs
Move the code from Xen to debugfs to make the code common
for other users as well.

Accked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Suzuki Poulose <suzuki@in.ibm.com>
[v1: Fixed rebase issues]
[v2: Fixed PPC compile issues]
Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-04-17 00:18:36 -04:00
Linus Torvalds
9479f0f801 Two fixes for regressions:
* one is a workaround that will be removed in v3.5 with proper fix in the tip/x86 tree,
  * the other is to fix drivers to load on PV (a previous patch made them only
    load in PVonHVM mode).
 
 The rest are just minor fixes in the various drivers and some cleanup in the
 core code.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1.4.11 (GNU/Linux)
 
 iQEcBAABAgAGBQJPfyVUAAoJEFjIrFwIi8fJUjUH/jbY5JavRqSlNELZW2A4Ta76
 8p00LqLHw/C56iHZcWKke8mqtWNb+ZfcQt7ZYcxDIYa4QWBL28x0OLAO2tOBIt37
 ZjYESWSdFJaJvmpADluWtFyGyZ9TYJllDTBm/jWj1ZtKSZvR1YkhuMXCS0f4AmGQ
 xFzSWJZUDdiOAqpN+VQD8wP00gfR8knQLg16XE2fvFdQo4XwpCtqLfHV/5pMMGdy
 Cs/ep6rq/7cdv/nshKOcBnw7RW8l3Xoi/28ht8k3DvAQ2VtFq1Tugv2G9pcCHwQG
 DIBkB3SOU6/v6P5at5+egKS5xR1fJetCWlkMd8kkbcdz2NPI4UDMkvOW6Q8yQls=
 =6Ve+
 -----END PGP SIGNATURE-----

Merge tag 'stable/for-linus-3.4-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen

Pull xen fixes from Konrad Rzeszutek Wilk:
 "Two fixes for regressions:
   * one is a workaround that will be removed in v3.5 with proper fix in
     the tip/x86 tree,
   * the other is to fix drivers to load on PV (a previous patch made
     them only load in PVonHVM mode).

  The rest are just minor fixes in the various drivers and some cleanup
  in the core code."

* tag 'stable/for-linus-3.4-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/pcifront: avoid pci_frontend_enable_msix() falsely returning success
  xen/pciback: fix XEN_PCI_OP_enable_msix result
  xen/smp: Remove unnecessary call to smp_processor_id()
  xen/x86: Workaround 'x86/ioapic: Add register level checks to detect bogus io-apic entries'
  xen: only check xen_platform_pci_unplug if hvm
2012-04-06 17:54:53 -07:00
Konrad Rzeszutek Wilk
940713bb2c xen/p2m: An early bootup variant of set_phys_to_machine
During early bootup we can't use alloc_page, so to allocate
leaf pages in the P2M we need to use extend_brk. For that
we are utilizing the early_alloc_p2m and early_alloc_p2m_middle
functions to do the job for us. This function follows the
same logic as set_phys_to_machine.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-04-06 17:03:06 -04:00
Konrad Rzeszutek Wilk
d5096850b4 xen/p2m: Collapse early_alloc_p2m_middle redundant checks.
At the start of the function we were checking for idx != 0
and bailing out. And later calling extend_brk if idx != 0.

That is unnecessary so remove that checks.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-04-06 17:03:04 -04:00