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: NAndre Przywara <andre.przywara@amd.com>
Link: http://lkml.kernel.org/r/20120530222356.GA28417@andromeda.dapyr.netSigned-off-by: NH. Peter Anvin <hpa@zytor.com>
Cc: <stable@vger.kernel.org>

The git commit  1ff2b0c3
"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: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

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.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

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: NLiang Tang <liang.tang@oracle.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Signed-off-by: NLin Ming <mlin@ss.pku.edu.cn>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Map native ipi vector to xen vector.
Implement apic ipi interface with xen_send_IPI_one.
Tested-by: NSteven Noonan <steven@uplinklabs.net>
Signed-off-by: NBen Guthro <ben@guthro.net>
Signed-off-by: NLin Ming <mlin@ss.pku.edu.cn>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

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: NDavid Vrabel <david.vrabel@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

They use the same set of arguments, so it is just the matter
of using the proper hypercall.
Acked-by: NDavid Vrabel <david.vrabel@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

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: NDavid Vrabel <david.vrabel@citrix.com>
[v2: Use populate hypercall]
[v3: Remove debug printks]
[v4: Simplify code]
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

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: NDavid Vrabel <david.vrabel@citrix.com>
[v1: Extended to the summary printks]
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

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: NJan Beulich <jbeulich@suse.com>
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>
[v1: Fixed compile error when CONFIG_PCI is not set]
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

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: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

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: NStefan Bader <stefan.bader@canonical.com>
Suggested-by: NBoris Ostrovsky <boris.ostrovsky@amd.com>
[v2: Bit-shift APIC ID by 24 bits]
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

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: NLin Ming <mlin@ss.pku.edu.cn>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Revert "xen/x86: Workaround 'x86/ioapic: Add register level checks to detect bogus io-apic entries'"

This reverts commit 2531d64b.

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: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Or rather just implement one different function as opposed
to the native one : the read function.

We synthesize the values.
Acked-by: NSuresh 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: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

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: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

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: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

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: NLiu, Jinsong <jinsong.liu@intel.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Signed-off-by: NThomas 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

Preparatory patch to use the generic idle thread allocation.
Signed-off-by: NThomas 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

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: NH. 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

This reverts commit b960d6c4.

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: NDan Carpenter <dan.carpenter@oracle.com>
Acked-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Use list_for_each_entry_safe and remove the spin_lock acquisition in
m2p_find_override.
Signed-off-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Move the code from Xen to debugfs to make the code common
for other users as well.
Accked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NSrivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: NSuzuki Poulose <suzuki@in.ibm.com>
[v1: Fixed rebase issues]
[v2: Fixed PPC compile issues]
Signed-off-by: NRaghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

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: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

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: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

For identity cases we want to call reserve_brk only on the boundary
conditions of the middle P2M (so P2M[x][y][0] = extend_brk). This is
to work around identify regions (PCI spaces, gaps in E820) which are not
aligned on 2MB regions.

However for the case were we want to allocate P2M middle leafs at the
early bootup stage, irregardless of this alignment check we need some
means of doing that.  For that we provide the new argument.
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

We are going to be using the early_alloc_p2m (and
early_alloc_p2m_middle) code in follow up patches which
are not related to setting identity pages.

Hence lets move the code out in its own function and
rename them as appropiate.
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

There is an extra and unnecessary call to smp_processor_id()
in cpu_bringup(). Remove it.
Signed-off-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

The above mentioned patch checks the IOAPIC and if it contains
-1, then it unmaps said IOAPIC. But under Xen we get this:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000040
IP: [<ffffffff8134e51f>] xen_irq_init+0x1f/0xb0
PGD 0
Oops: 0002 [#1] SMP
CPU 0
Modules linked in:

Pid: 1, comm: swapper/0 Not tainted 3.2.10-3.fc16.x86_64 #1 Dell Inc. Inspiron
1525                  /0U990C
RIP: e030:[<ffffffff8134e51f>]  [<ffffffff8134e51f>] xen_irq_init+0x1f/0xb0
RSP: e02b: ffff8800d42cbb70  EFLAGS: 00010202
RAX: 0000000000000000 RBX: 00000000ffffffef RCX: 0000000000000001
RDX: 0000000000000040 RSI: 00000000ffffffef RDI: 0000000000000001
RBP: ffff8800d42cbb80 R08: ffff8800d6400000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 00000000ffffffef
R13: 0000000000000001 R14: 0000000000000001 R15: 0000000000000010
FS:  0000000000000000(0000) GS:ffff8800df5fe000(0000) knlGS:0000000000000000
CS:  e033 DS: 0000 ES: 0000 CR0:000000008005003b
CR2: 0000000000000040 CR3: 0000000001a05000 CR4: 0000000000002660
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process swapper/0 (pid: 1, threadinfo ffff8800d42ca000, task ffff8800d42d0000)
Stack:
 00000000ffffffef 0000000000000010 ffff8800d42cbbe0 ffffffff8134f157
 ffffffff8100a9b2 ffffffff8182ffd1 00000000000000a0 00000000829e7384
 0000000000000002 0000000000000010 00000000ffffffff 0000000000000000
Call Trace:
 [<ffffffff8134f157>] xen_bind_pirq_gsi_to_irq+0x87/0x230
 [<ffffffff8100a9b2>] ? check_events+0x12+0x20
 [<ffffffff814bab42>] xen_register_pirq+0x82/0xe0
 [<ffffffff814bac1a>] xen_register_gsi.part.2+0x4a/0xd0
 [<ffffffff814bacc0>] acpi_register_gsi_xen+0x20/0x30
 [<ffffffff8103036f>] acpi_register_gsi+0xf/0x20
 [<ffffffff8131abdb>] acpi_pci_irq_enable+0x12e/0x202
 [<ffffffff814bc849>] pcibios_enable_device+0x39/0x40
 [<ffffffff812dc7ab>] do_pci_enable_device+0x4b/0x70
 [<ffffffff812dc878>] __pci_enable_device_flags+0xa8/0xf0
 [<ffffffff812dc8d3>] pci_enable_device+0x13/0x20

The reason we are dying is b/c the call acpi_get_override_irq() is used,
which returns the polarity and trigger for the IRQs. That function calls
mp_find_ioapics to get the 'struct ioapic' structure - which along with the
mp_irq[x] is used to figure out the default values and the polarity/trigger
overrides. Since the mp_find_ioapics now returns -1 [b/c the IOAPIC is filled
with 0xffffffff], the acpi_get_override_irq() stops trying to lookup in the
mp_irq[x] the proper INT_SRV_OVR and we can't install the SCI interrupt.

The proper fix for this is going in v3.5 and adds an x86_io_apic_ops
struct so that platforms can override it. But for v3.4 lets carry this
work-around. This patch does that by providing a slightly different variant
of the fake IOAPIC entries.
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

This has been obsolescent for a while, fix documentation and
misc comments.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Adapt core x86 and IA64 architecture code for dma_map_ops changes: replace
alloc/free_coherent with generic alloc/free methods.
Signed-off-by: NAndrzej Pietrasiewicz <andrzej.p@samsung.com>
Acked-by: NKyungmin Park <kyungmin.park@samsung.com>
[removed swiotlb related changes and replaced it with wrappers,
 merged with IA64 patch to avoid inter-patch dependences in intel-iommu code]
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NTony Luck <tony.luck@intel.com>

The CPU hotplug code has now a callback to help bring up the CPU.
Without the call we end up getting:

 BUG: soft lockup - CPU#0 stuck for 29s! [migration/0:6]
Modules linked in:
CPU ] Pid: 6, comm: migration/0 Not tainted 3.3.0upstream-01180-ged378a52 #1 Dell Inc. PowerEdge T105 /0RR825
RIP: e030:[<ffffffff810d3b8b>]  [<ffffffff810d3b8b>] stop_machine_cpu_stop+0x7b/0xf0
RSP: e02b:ffff8800ceaabdb0  EFLAGS: 00000293
.. snip..
Call Trace:
 [<ffffffff810d3b10>] ? stop_one_cpu_nowait+0x50/0x50
 [<ffffffff810d3841>] cpu_stopper_thread+0xf1/0x1c0
 [<ffffffff815a9776>] ? __schedule+0x3c6/0x760
 [<ffffffff815aa749>] ? _raw_spin_unlock_irqrestore+0x19/0x30
 [<ffffffff810d3750>] ? res_counter_charge+0x150/0x150
 [<ffffffff8108dc76>] kthread+0x96/0xa0
 [<ffffffff815b27e4>] kernel_thread_helper+0x4/0x10
 [<ffffffff815aacbc>] ? retint_restore_ar

Thix fixes it.
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

By using the functionality provided by "[CPUFREQ]: provide
disable_cpuidle() function to disable the API."

Under the Xen hypervisor we do not want the initial domain to exercise
the cpufreq scaling drivers. This is b/c the Xen hypervisor is
in charge of doing this as well and we can end up with both the
Linux kernel and the hypervisor trying to change the P-states
leading to weird performance issues.
Acked-by: NJan Beulich <jbeulich@suse.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[v2: Fix compile error spotted by Benjamin Schweikert <b.schweikert@googlemail.com>]

For the hypervisor to take advantage of the MWAIT support it needs
to extract from the ACPI _CST the register address. But the
hypervisor does not have the support to parse DSDT so it relies on
the initial domain (dom0) to parse the ACPI Power Management information
and push it up to the hypervisor. The pushing of the data is done
by the processor_harveset_xen module which parses the information that
the ACPI parser has graciously exposed in 'struct acpi_processor'.

For the ACPI parser to also expose the Cx states for MWAIT, we need
to expose the MWAIT capability (leaf 1). Furthermore we also need to
expose the MWAIT_LEAF capability (leaf 5) for cstate.c to properly
function.

The hypervisor could expose these flags when it traps the XEN_EMULATE_PREFIX
operations, but it can't do it since it needs to be backwards compatible.
Instead we choose to use the native CPUID to figure out if the MWAIT
capability exists and use the XEN_SET_PDC query hypercall to figure out
if the hypervisor wants us to expose the MWAIT_LEAF capability or not.

Note: The XEN_SET_PDC query was implemented in c/s 23783:
"ACPI: add _PDC input override mechanism".

With this in place, instead of
 C3 ACPI IOPORT 415
we get now
 C3:ACPI FFH INTEL MWAIT 0x20

Note: The cpu_idle which would be calling the mwait variants for idling
never gets set b/c we set the default pm_idle to be the hypercall variant.
Acked-by: NJan Beulich <JBeulich@suse.com>
[v2: Fix missing header file include and #ifdef]
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

We needed that call in the past to force the kernel to use
default_idle (which called safe_halt, which called xen_safe_halt).

But set_pm_idle_to_default() does now that, so there is no need
to use this boot option operand.
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

[Pls also look at https://lkml.org/lkml/2012/2/10/228]

Using of PAT to change pages from WB to WC works quite nicely.
Changing it back to WB - not so much. The crux of the matter is
that the code that does this (__page_change_att_set_clr) has only
limited information so when it tries to the change it gets
the "raw" unfiltered information instead of the properly filtered one -
and the "raw" one tell it that PSE bit is on (while infact it
is not).  As a result when the PTE is set to be WB from WC, we get
tons of:

:WARNING: at arch/x86/xen/mmu.c:475 xen_make_pte+0x67/0xa0()
:Hardware name: HP xw4400 Workstation
.. snip..
:Pid: 27, comm: kswapd0 Tainted: G        W    3.2.2-1.fc16.x86_64 #1
:Call Trace:
: [<ffffffff8106dd1f>] warn_slowpath_common+0x7f/0xc0
: [<ffffffff8106dd7a>] warn_slowpath_null+0x1a/0x20
: [<ffffffff81005a17>] xen_make_pte+0x67/0xa0
: [<ffffffff810051bd>] __raw_callee_save_xen_make_pte+0x11/0x1e
: [<ffffffff81040e15>] ? __change_page_attr_set_clr+0x9d5/0xc00
: [<ffffffff8114c2e8>] ? __purge_vmap_area_lazy+0x158/0x1d0
: [<ffffffff8114cca5>] ? vm_unmap_aliases+0x175/0x190
: [<ffffffff81041168>] change_page_attr_set_clr+0x128/0x4c0
: [<ffffffff81041542>] set_pages_array_wb+0x42/0xa0
: [<ffffffff8100a9b2>] ? check_events+0x12/0x20
: [<ffffffffa0074d4c>] ttm_pages_put+0x1c/0x70 [ttm]
: [<ffffffffa0074e98>] ttm_page_pool_free+0xf8/0x180 [ttm]
: [<ffffffffa0074f78>] ttm_pool_mm_shrink+0x58/0x90 [ttm]
: [<ffffffff8112ba04>] shrink_slab+0x154/0x310
: [<ffffffff8112f17a>] balance_pgdat+0x4fa/0x6c0
: [<ffffffff8112f4b8>] kswapd+0x178/0x3d0
: [<ffffffff815df134>] ? __schedule+0x3d4/0x8c0
: [<ffffffff81090410>] ? remove_wait_queue+0x50/0x50
: [<ffffffff8112f340>] ? balance_pgdat+0x6c0/0x6c0
: [<ffffffff8108fb6c>] kthread+0x8c/0xa0

for every page. The proper fix for this is has been posted
and is https://lkml.org/lkml/2012/2/10/228
"x86/cpa: Use pte_attrs instead of pte_flags on CPA/set_p.._wb/wc operations."
along with a detailed description of the problem and solution.

But since that posting has gone nowhere I am proposing
this band-aid solution so that at least users don't get
the page corruption (the pages that are WC don't get changed to WB
and end up being recycled for filesystem or other things causing
mysterious crashes).

The negative impact of this patch is that users of WC flag
(which are InfiniBand, radeon, nouveau drivers) won't be able
to set that flag - so they are going to see performance degradation.
But stability is more important here.

Fixes RH BZ# 742032, 787403, and 745574
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

commit 7347b408 "xen: Allow
unprivileged Xen domains to create iomap pages" added a redundant
line in the early bootup code to filter out the PTE. That
filtering is already done a bit earlier so this extra processing
is not required.
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

When a user offlines a VCPU and then onlines it, we get:

NMI watchdog disabled (cpu2): hardware events not enabled
BUG: scheduling while atomic: swapper/2/0/0x00000002
Modules linked in: dm_multipath dm_mod xen_evtchn iscsi_boot_sysfs iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi scsi_mod libcrc32c crc32c radeon fbco
 ttm bitblit softcursor drm_kms_helper xen_blkfront xen_netfront xen_fbfront fb_sys_fops sysimgblt sysfillrect syscopyarea xen_kbdfront xenfs [last unloaded:

Pid: 0, comm: swapper/2 Tainted: G           O 3.2.0phase15.1-00003-gd6f7f5b-dirty #4
Call Trace:
 [<ffffffff81070571>] __schedule_bug+0x61/0x70
 [<ffffffff8158eb78>] __schedule+0x798/0x850
 [<ffffffff8158ed6a>] schedule+0x3a/0x50
 [<ffffffff810349be>] cpu_idle+0xbe/0xe0
 [<ffffffff81583599>] cpu_bringup_and_idle+0xe/0x10

The reason for this should be obvious from this call-chain:
cpu_bringup_and_idle:
 \- cpu_bringup
  |   \-[preempt_disable]
  |
  |- cpu_idle
       \- play_dead [assuming the user offlined the VCPU]
       |     \
       |     +- (xen_play_dead)
       |          \- HYPERVISOR_VCPU_off [so VCPU is dead, once user
       |          |                       onlines it starts from here]
       |          \- cpu_bringup [preempt_disable]
       |
       +- preempt_enable_no_reschedule()
       +- schedule()
       \- preempt_enable()

So we have two preempt_disble() and one preempt_enable(). Calling
preempt_enable() after the cpu_bringup() in the xen_play_dead
fixes the imbalance.
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>