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Commit Graph

144 Commits

Author SHA1 Message Date
David Vrabel
f5775e0b61 x86/xen: discard RAM regions above the maximum reservation
During setup, discard RAM regions that are above the maximum
reservation (instead of marking them as E820_UNUSABLE).  This allows
hotplug memory to be placed at these addresses.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2015-10-23 14:20:03 +01:00
Malcolm Crossley
64c98e7f49 x86/xen: Do not clip xen_e820_map to xen_e820_map_entries when sanitizing map
Sanitizing the e820 map may produce extra E820 entries which would result in
the topmost E820 entries being removed. The removed entries would typically
include the top E820 usable RAM region and thus result in the domain having
signicantly less RAM available to it.

Fix by allowing sanitize_e820_map to use the full size of the allocated E820
array.

Signed-off-by: Malcolm Crossley <malcolm.crossley@citrix.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-09-28 18:03:38 +01:00
Juergen Gross
24f775a660 xen: use correct type for HYPERVISOR_memory_op()
HYPERVISOR_memory_op() is defined to return an "int" value. This is
wrong, as the Xen hypervisor will return "long".

The sub-function XENMEM_maximum_reservation returns the maximum
number of pages for the current domain. An int will overflow for a
domain configured with 8TB of memory or more.

Correct this by using the correct type.

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-09-28 14:48:52 +01:00
Juergen Gross
626d750866 xen: switch extra memory accounting to use pfns
Instead of using physical addresses for accounting of extra memory
areas available for ballooning switch to pfns as this is much less
error prone regarding partial pages.

Reported-by: Roger Pau Monné <roger.pau@citrix.com>
Tested-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-09-08 16:28:06 +01:00
Juergen Gross
cb9e444b5a xen: limit memory to architectural maximum
When a pv-domain (including dom0) is started it tries to size it's
p2m list according to the maximum possible memory amount it ever can
achieve. Limit the initial maximum memory size to the architectural
limit of the hardware in order to avoid overflows during remapping
of memory.

This problem will occur when dom0 is started with an initial memory
size being a multiple of 1GB, but without specifying it's maximum
memory size. The kernel must be configured without
CONFIG_XEN_BALLOON_MEMORY_HOTPLUG for the problem to happen.

Reported-by: Roger Pau Monné <roger.pau@citrix.com>
Tested-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-09-08 16:28:05 +01:00
Juergen Gross
ab24507cfa xen: avoid another early crash of memory limited dom0
Commit b1c9f169047b ("xen: split counting of extra memory pages...")
introduced an error when dom0 was started with limited memory occurring
only on some hardware.

The problem arises in case dom0 is started with initial memory and
maximum memory being the same. The kernel must be configured without
CONFIG_XEN_BALLOON_MEMORY_HOTPLUG for the problem to happen. If all
of this is true and the E820 map of the machine is sparse (some areas
are not covered) then the machine might crash early in the boot
process.

An example E820 map triggering the problem looks like this:

[    0.000000] e820: BIOS-provided physical RAM map:
[    0.000000] BIOS-e820: [mem 0x0000000000000000-0x000000000009d7ff] usable
[    0.000000] BIOS-e820: [mem 0x000000000009d800-0x000000000009ffff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000000e0000-0x00000000000fffff] reserved
[    0.000000] BIOS-e820: [mem 0x0000000000100000-0x00000000cf7fafff] usable
[    0.000000] BIOS-e820: [mem 0x00000000cf7fb000-0x00000000cf95ffff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000cf960000-0x00000000cfb62fff] ACPI NVS
[    0.000000] BIOS-e820: [mem 0x00000000cfb63000-0x00000000cfd14fff] usable
[    0.000000] BIOS-e820: [mem 0x00000000cfd15000-0x00000000cfd61fff] ACPI NVS
[    0.000000] BIOS-e820: [mem 0x00000000cfd62000-0x00000000cfd6cfff] ACPI data
[    0.000000] BIOS-e820: [mem 0x00000000cfd6d000-0x00000000cfd6ffff] ACPI NVS
[    0.000000] BIOS-e820: [mem 0x00000000cfd70000-0x00000000cfd70fff] usable
[    0.000000] BIOS-e820: [mem 0x00000000cfd71000-0x00000000cfea8fff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000cfea9000-0x00000000cfeb9fff] ACPI NVS
[    0.000000] BIOS-e820: [mem 0x00000000cfeba000-0x00000000cfecafff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000cfecb000-0x00000000cfecbfff] ACPI NVS
[    0.000000] BIOS-e820: [mem 0x00000000cfecc000-0x00000000cfedbfff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000cfedc000-0x00000000cfedcfff] ACPI NVS
[    0.000000] BIOS-e820: [mem 0x00000000cfedd000-0x00000000cfeddfff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000cfede000-0x00000000cfee3fff] ACPI NVS
[    0.000000] BIOS-e820: [mem 0x00000000cfee4000-0x00000000cfef6fff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000cfef7000-0x00000000cfefffff] usable
[    0.000000] BIOS-e820: [mem 0x00000000e0000000-0x00000000efffffff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000fec00000-0x00000000fec00fff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000fec10000-0x00000000fec10fff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000fed00000-0x00000000fed00fff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000fed40000-0x00000000fed44fff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000fed61000-0x00000000fed70fff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000fed80000-0x00000000fed8ffff] reserved
[    0.000000] BIOS-e820: [mem 0x00000000ff000000-0x00000000ffffffff] reserved
[    0.000000] BIOS-e820: [mem 0x0000000100001000-0x000000020effffff] usable

In this case the area a0000-dffff isn't present in the map. This will
confuse the memory setup of the domain when remapping the memory from
such holes to populated areas.

To avoid the problem the accounting of to be remapped memory has to
count such holes in the E820 map as well.

Reported-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-09-08 16:28:04 +01:00
Juergen Gross
eafd72e016 xen: avoid early crash of memory limited dom0
Commit b1c9f169047b ("xen: split counting of extra memory pages...")
introduced an error when dom0 was started with limited memory.

The problem arises in case dom0 is started with initial memory and
maximum memory being the same and exactly a multiple of 1 GB. The
kernel must be configured without CONFIG_XEN_BALLOON_MEMORY_HOTPLUG
for the problem to happen. In this case it will crash very early
during boot due to the virtual mapped p2m list not being large
enough to be able to remap any memory:

(XEN) Freed 304kB init memory.
mapping kernel into physical memory
about to get started...
(XEN) traps.c:459:d0v0 Unhandled invalid opcode fault/trap [#6] on VCPU 0 [ec=0000]
(XEN) domain_crash_sync called from entry.S: fault at ffff82d080229a93 create_bounce_frame+0x12b/0x13a
(XEN) Domain 0 (vcpu#0) crashed on cpu#0:
(XEN) ----[ Xen-4.5.2-pre  x86_64  debug=n Not tainted ]----
(XEN) CPU:    0
(XEN) RIP:    e033:[<ffffffff81d120cb>]
(XEN) RFLAGS: 0000000000000206   EM: 1 CONTEXT: pv guest (d0v0)
(XEN) rax: ffffffff81db2000   rbx: 000000004d000000   rcx: 0000000000000000
(XEN) rdx: 000000004d000000   rsi: 0000000000063000   rdi: 000000004d063000
(XEN) rbp: ffffffff81c03d78   rsp: ffffffff81c03d28   r8:  0000000000023000
(XEN) r9:  00000001040ff000   r10: 0000000000007ff0   r11: 0000000000000000
(XEN) r12: 0000000000063000   r13: 000000000004d000   r14: 0000000000000063
(XEN) r15: 0000000000000063   cr0: 0000000080050033   cr4: 00000000000006f0
(XEN) cr3: 0000000105c0f000   cr2: ffffc90000268000
(XEN) ds: 0000   es: 0000   fs: 0000   gs: 0000   ss: e02b   cs: e033
(XEN) Guest stack trace from rsp=ffffffff81c03d28:
(XEN)   0000000000000000 0000000000000000 ffffffff81d120cb 000000010000e030
(XEN)   0000000000010006 ffffffff81c03d68 000000000000e02b ffffffffffffffff
(XEN)   0000000000000063 000000000004d063 ffffffff81c03de8 ffffffff81d130a7
(XEN)   ffffffff81c03de8 000000000004d000 00000001040ff000 0000000000105db1
(XEN)   00000001040ff001 000000000004d062 ffff8800092d6ff8 0000000002027000
(XEN)   ffff8800094d8340 ffff8800092d6ff8 00003ffffffff000 ffff8800092d7ff8
(XEN)   ffffffff81c03e48 ffffffff81d13c43 ffff8800094d8000 ffff8800094d9000
(XEN)   0000000000000000 ffff8800092d6000 00000000092d6000 000000004cfbf000
(XEN)   00000000092d6000 00000000052d5442 0000000000000000 0000000000000000
(XEN)   ffffffff81c03ed8 ffffffff81d185c1 0000000000000000 0000000000000000
(XEN)   ffffffff81c03e78 ffffffff810f8ca4 ffffffff81c03ed8 ffffffff8171a15d
(XEN)   0000000000000010 ffffffff81c03ee8 0000000000000000 0000000000000000
(XEN)   ffffffff81f0e402 ffffffffffffffff ffffffff81dae900 0000000000000000
(XEN)   0000000000000000 0000000000000000 ffffffff81c03f28 ffffffff81d0cf0f
(XEN)   0000000000000000 0000000000000000 0000000000000000 ffffffff81db82e0
(XEN)   0000000000000000 0000000000000000 0000000000000000 0000000000000000
(XEN)   ffffffff81c03f38 ffffffff81d0c603 ffffffff81c03ff8 ffffffff81d11c86
(XEN)   0300000100000032 0000000000000005 0000000000000020 0000000000000000
(XEN)   0000000000000000 0000000000000000 0000000000000000 0000000000000000
(XEN)   0000000000000000 0000000000000000 0000000000000000 0000000000000000
(XEN) Domain 0 crashed: rebooting machine in 5 seconds.

This can be avoided by allocating aneough space for the p2m to cover
the maximum memory of dom0 plus the identity mapped holes required
for PCI space, BIOS etc.

Reported-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-09-08 16:28:04 +01:00
Juergen Gross
cb3eb85013 xen: remove no longer needed p2m.h
Cleanup by removing arch/x86/xen/p2m.h as it isn't needed any more.

Most definitions in this file are used in p2m.c only. Move those into
p2m.c.

set_phys_range_identity() is already declared in
arch/x86/include/asm/xen/page.h, add __init annotation there.

MAX_REMAP_RANGES isn't used at all, just delete it.

The only define left is P2M_PER_PAGE which is moved to page.h as well.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-08-20 12:24:25 +01:00
Juergen Gross
c70727a5bc xen: allow more than 512 GB of RAM for 64 bit pv-domains
64 bit pv-domains under Xen are limited to 512 GB of RAM today. The
main reason has been the 3 level p2m tree, which was replaced by the
virtual mapped linear p2m list. Parallel to the p2m list which is
being used by the kernel itself there is a 3 level mfn tree for usage
by the Xen tools and eventually for crash dump analysis. For this tree
the linear p2m list can serve as a replacement, too. As the kernel
can't know whether the tools are capable of dealing with the p2m list
instead of the mfn tree, the limit of 512 GB can't be dropped in all
cases.

This patch replaces the hard limit by a kernel parameter which tells
the kernel to obey the 512 GB limit or not. The default is selected by
a configuration parameter which specifies whether the 512 GB limit
should be active per default for domUs (domain save/restore/migration
and crash dump analysis are affected).

Memory above the domain limit is returned to the hypervisor instead of
being identity mapped, which was wrong anyway.

The kernel configuration parameter to specify the maximum size of a
domain can be deleted, as it is not relevant any more.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-08-20 12:24:24 +01:00
Juergen Gross
70e6119955 xen: move p2m list if conflicting with e820 map
Check whether the hypervisor supplied p2m list is placed at a location
which is conflicting with the target E820 map. If this is the case
relocate it to a new area unused up to now and compliant to the E820
map.

As the p2m list might by huge (up to several GB) and is required to be
mapped virtually, set up a temporary mapping for the copied list.

For pvh domains just delete the p2m related information from start
info instead of reserving the p2m memory, as we don't need it at all.

For 32 bit kernels adjust the memblock_reserve() parameters in order
to cover the page tables only. This requires to memblock_reserve() the
start_info page on it's own.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-08-20 12:24:24 +01:00
Juergen Gross
4b9c15377f xen: check for initrd conflicting with e820 map
Check whether the initrd is placed at a location which is conflicting
with the target E820 map. If this is the case relocate it to a new
area unused up to now and compliant to the E820 map.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-08-20 12:24:22 +01:00
Juergen Gross
04414baab5 xen: check pre-allocated page tables for conflict with memory map
Check whether the page tables built by the domain builder are at
memory addresses which are in conflict with the target memory map.
If this is the case just panic instead of running into problems
later.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-08-20 12:24:21 +01:00
Juergen Gross
808fdb7193 xen: check for kernel memory conflicting with memory layout
Checks whether the pre-allocated memory of the loaded kernel is in
conflict with the target memory map. If this is the case, just panic
instead of run into problems later, as there is nothing we can do
to repair this situation.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-08-20 12:24:21 +01:00
Juergen Gross
9ddac5b724 xen: find unused contiguous memory area
For being able to relocate pre-allocated data areas like initrd or
p2m list it is mandatory to find a contiguous memory area which is
not yet in use and doesn't conflict with the memory map we want to
be in effect.

In case such an area is found reserve it at once as this will be
required to be done in any case.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-08-20 12:24:20 +01:00
Juergen Gross
e612b4a7db xen: check memory area against e820 map
Provide a service routine to check a physical memory area against the
E820 map. The routine will return false if the complete area is RAM
according to the E820 map and true otherwise.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-08-20 12:24:20 +01:00
Juergen Gross
5097cdf6ce xen: split counting of extra memory pages from remapping
Memory pages in the initial memory setup done by the Xen hypervisor
conflicting with the target E820 map are remapped. In order to do this
those pages are counted and remapped in xen_set_identity_and_remap().

Split the counting from the remapping operation to be able to setup
the needed memory sizes in time but doing the remap operation at a
later time. This enables us to simplify the interface to
xen_set_identity_and_remap() as the number of remapped and released
pages is no longer needed here.

Finally move the remapping further down to prepare relocating
conflicting memory contents before the memory might be clobbered by
xen_set_identity_and_remap(). This requires to not destroy the Xen
E820 map when the one for the system is being constructed.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-08-20 12:24:19 +01:00
Juergen Gross
69632ecfcd xen: move static e820 map to global scope
Instead of using a function local static e820 map in xen_memory_setup()
and calling various functions in the same source with the map as a
parameter use a map directly accessible by all functions in the source.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-08-20 12:24:18 +01:00
Juergen Gross
8f5b0c6398 xen: eliminate scalability issues from initial mapping setup
Direct Xen to place the initial P->M table outside of the initial
mapping, as otherwise the 1G (implementation) / 2G (theoretical)
restriction on the size of the initial mapping limits the amount
of memory a domain can be handed initially.

As the initial P->M table is copied rather early during boot to
domain private memory and it's initial virtual mapping is dropped,
the easiest way to avoid virtual address conflicts with other
addresses in the kernel is to use a user address area for the
virtual address of the initial P->M table. This allows us to just
throw away the page tables of the initial mapping after the copy
without having to care about address invalidation.

It should be noted that this patch won't enable a pv-domain to USE
more than 512 GB of RAM. It just enables it to be started with a
P->M table covering more memory. This is especially important for
being able to boot a Dom0 on a system with more than 512 GB memory.

Signed-off-by: Juergen Gross <jgross@suse.com>
Based-on-patch-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-08-20 12:24:18 +01:00
Juergen Gross
a3f5239650 x86/xen: add some __init and static annotations in arch/x86/xen/setup.c
Some more functions in arch/x86/xen/setup.c can be made "__init".
xen_ignore_unusable() can be made "static".

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-01-28 10:00:36 +00:00
Juergen Gross
3ba5c867ca x86/xen: use correct types for addresses in arch/x86/xen/setup.c
In many places in arch/x86/xen/setup.c wrong types are used for
physical addresses (u64 or unsigned long long). Use phys_addr_t
instead.

Use macros already defined instead of open coding them.

Correct some other type mismatches.

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-01-28 10:00:10 +00:00
Juergen Gross
f0feed10aa x86/xen: cleanup arch/x86/xen/setup.c
Remove extern declarations in arch/x86/xen/setup.c which are either
not used or redundant. Move needed other extern declarations to
xen-ops.h

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-01-28 09:59:46 +00:00
Juergen Gross
9a17ad7f3d xen: check for zero sized area when invalidating memory
With the introduction of the linear mapped p2m list setting memory
areas to "invalid" had to be delayed. When doing the invalidation
make sure no zero sized areas are processed.

Signed-off-by: Juegren Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-01-12 10:09:55 +00:00
Juergen Gross
e86f949667 xen: use correct type for physical addresses
When converting a pfn to a physical address be sure to use 64 bit
wide types or convert the physical address to a pfn if possible.

Signed-off-by: Juergen Gross <jgross@suse.com>
Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-01-12 10:09:48 +00:00
David Vrabel
a97dae1a2e x86/xen: add extra memory for remapped frames during setup
If the non-RAM regions in the e820 memory map are larger than the size
of the initial balloon, a BUG was triggered as the frames are remaped
beyond the limit of the linear p2m.  The frames are remapped into the
initial balloon area (xen_extra_mem) but not enough of this is
available.

Ensure enough extra memory regions are added for these remapped
frames.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
2015-01-08 13:52:37 +00:00
David Vrabel
bc7142cf79 x86/xen: don't count how many PFNs are identity mapped
This accounting is just used to print a diagnostic message that isn't
very useful.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
2015-01-08 13:52:36 +00:00
Juergen Gross
76f0a486fa xen: annotate xen_set_identity_and_remap_chunk() with __init
Commit 5b8e7d8054 removed the __init
annotation from xen_set_identity_and_remap_chunk(). Add it again.

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-12-08 10:55:30 +00:00
Juergen Gross
5b8e7d8054 xen: Delay invalidating extra memory
When the physical memory configuration is initialized the p2m entries
for not pouplated memory pages are set to "invalid". As those pages
are beyond the hypervisor built p2m list the p2m tree has to be
extended.

This patch delays processing the extra memory related p2m entries
during the boot process until some more basic memory management
functions are callable. This removes the need to create new p2m
entries until virtual memory management is available.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-12-04 14:08:59 +00:00
Juergen Gross
1f3ac86b4c xen: Delay remapping memory of pv-domain
Early in the boot process the memory layout of a pv-domain is changed
to match the E820 map (either the host one for Dom0 or the Xen one)
regarding placement of RAM and PCI holes. This requires removing memory
pages initially located at positions not suitable for RAM and adding
them later at higher addresses where no restrictions apply.

To be able to operate on the hypervisor supported p2m list until a
virtual mapped linear p2m list can be constructed, remapping must
be delayed until virtual memory management is initialized, as the
initial p2m list can't be extended unlimited at physical memory
initialization time due to it's fixed structure.

A further advantage is the reduction in complexity and code volume as
we don't have to be careful regarding memory restrictions during p2m
updates.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-12-04 14:08:48 +00:00
Martin Kelly
1ea644c8f9 x86/xen: panic on bad Xen-provided memory map
Panic if Xen provides a memory map with 0 entries. Although this is
unlikely, it is better to catch the error at the point of seeing the map
than later on as a symptom of some other crash.

Signed-off-by: Martin Kelly <martkell@amazon.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-10-23 16:24:02 +01:00
Matt Rushton
4fbb67e3c8 xen/setup: Remap Xen Identity Mapped RAM
Instead of ballooning up and down dom0 memory this remaps the existing mfns
that were replaced by the identity map. The reason for this is that the
existing implementation ballooned memory up and and down which caused dom0
to have discontiguous pages. In some cases this resulted in the use of bounce
buffers which reduced network I/O performance significantly. This change will
honor the existing order of the pages with the exception of some boundary
conditions.

To do this we need to update both the Linux p2m table and the Xen m2p table.
Particular care must be taken when updating the p2m table since it's important
to limit table memory consumption and reuse the existing leaf pages which get
freed when an entire leaf page is set to the identity map. To implement this,
mapping updates are grouped into blocks with table entries getting cached
temporarily and then released.

On my test system before:
Total pages: 2105014
Total contiguous: 1640635

After:
Total pages: 2105014
Total contiguous: 2098904

Signed-off-by: Matthew Rushton <mrushton@amazon.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-09-23 13:36:18 +00:00
Linus Torvalds
3d09c62394 xen: regression and PVH fixes for 3.16-rc1
- Fix dom0 PVH memory setup on latest unstable Xen releases.
 - Fix 64-bit x86 PV guest boot failure on Xen 3.1 and earlier.
 - Fix resume regression on non-PV (auto-translated physmap) guests.
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Merge tag 'stable/for-linus-3.16-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull Xen fixes from David Vrabel:
 "Xen regression and PVH fixes for 3.16-rc1

   - fix dom0 PVH memory setup on latest unstable Xen releases
   - fix 64-bit x86 PV guest boot failure on Xen 3.1 and earlier
   - fix resume regression on non-PV (auto-translated physmap) guests"

* tag 'stable/for-linus-3.16-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/grant-table: fix suspend for non-PV guests
  x86/xen: no need to explicitly register an NMI callback
  Revert "xen/pvh: Update E820 to work with PVH (v2)"
  x86/xen: fix memory setup for PVH dom0
2014-06-19 07:53:27 -10:00
David Vrabel
ea9f9274bf x86/xen: no need to explicitly register an NMI callback
Remove xen_enable_nmi() to fix a 64-bit guest crash when registering
the NMI callback on Xen 3.1 and earlier.

It's not needed since the NMI callback is set by a set_trap_table
hypercall (in xen_load_idt() or xen_write_idt_entry()).

It's also broken since it only set the current VCPU's callback.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
2014-06-18 10:57:41 +01:00
Linus Torvalds
a0abcf2e8f Merge branch 'x86/vdso' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next
Pull x86 cdso updates from Peter Anvin:
 "Vdso cleanups and improvements largely from Andy Lutomirski.  This
  makes the vdso a lot less ''special''"

* 'x86/vdso' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/vdso, build: Make LE access macros clearer, host-safe
  x86/vdso, build: Fix cross-compilation from big-endian architectures
  x86/vdso, build: When vdso2c fails, unlink the output
  x86, vdso: Fix an OOPS accessing the HPET mapping w/o an HPET
  x86, mm: Replace arch_vma_name with vm_ops->name for vsyscalls
  x86, mm: Improve _install_special_mapping and fix x86 vdso naming
  mm, fs: Add vm_ops->name as an alternative to arch_vma_name
  x86, vdso: Fix an OOPS accessing the HPET mapping w/o an HPET
  x86, vdso: Remove vestiges of VDSO_PRELINK and some outdated comments
  x86, vdso: Move the vvar and hpet mappings next to the 64-bit vDSO
  x86, vdso: Move the 32-bit vdso special pages after the text
  x86, vdso: Reimplement vdso.so preparation in build-time C
  x86, vdso: Move syscall and sysenter setup into kernel/cpu/common.c
  x86, vdso: Clean up 32-bit vs 64-bit vdso params
  x86, mm: Ensure correct alignment of the fixmap
2014-06-05 08:05:29 -07:00
David Vrabel
562658f3dc Revert "xen/pvh: Update E820 to work with PVH (v2)"
This reverts commit 9103bb0f82.

Now than xen_memory_setup() is not called for auto-translated guests,
we can remove this commit.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Tested-by: Roger Pau Monné <roger.pau@citrix.com>
2014-06-05 14:23:16 +01:00
David Vrabel
abacaadc41 x86/xen: fix memory setup for PVH dom0
Since af06d66ee32b (x86: fix setup of PVH Dom0 memory map) in Xen, PVH
dom0 need only use the memory memory provided by Xen which has already
setup all the correct holes.

xen_memory_setup() then ends up being trivial for a PVH guest so
introduce a new function (xen_auto_xlated_memory_setup()).

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Tested-by: Roger Pau Monné <roger.pau@citrix.com>
2014-06-05 14:22:27 +01:00
David Vrabel
25b884a83d x86/xen: set regions above the end of RAM as 1:1
PCI devices may have BARs located above the end of RAM so mark such
frames as identity frames in the p2m (instead of the default of
missing).

PFNs outside the p2m (above MAX_P2M_PFN) are also considered to be
identity frames for the same reason.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2014-05-15 16:15:18 +01:00
David Vrabel
2dcc9a3de1 x86/xen: only warn once if bad MFNs are found during setup
In xen_add_extra_mem(), if the WARN() checks for bad MFNs trigger it is
likely that they will trigger at lot, spamming the log.

Use WARN_ONCE() instead.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2014-05-15 16:15:01 +01:00
Andy Lutomirski
6f121e548f x86, vdso: Reimplement vdso.so preparation in build-time C
Currently, vdso.so files are prepared and analyzed by a combination
of objcopy, nm, some linker script tricks, and some simple ELF
parsers in the kernel.  Replace all of that with plain C code that
runs at build time.

All five vdso images now generate .c files that are compiled and
linked in to the kernel image.

This should cause only one userspace-visible change: the loaded vDSO
images are stripped more heavily than they used to be.  Everything
outside the loadable segment is dropped.  In particular, this causes
the section table and section name strings to be missing.  This
should be fine: real dynamic loaders don't load or inspect these
tables anyway.  The result is roughly equivalent to eu-strip's
--strip-sections option.

The purpose of this change is to enable the vvar and hpet mappings
to be moved to the page following the vDSO load segment.  Currently,
it is possible for the section table to extend into the page after
the load segment, so, if we map it, it risks overlapping the vvar or
hpet page.  This happens whenever the load segment is just under a
multiple of PAGE_SIZE.

The only real subtlety here is that the old code had a C file with
inline assembler that did 'call VDSO32_vsyscall' and a linker script
that defined 'VDSO32_vsyscall = __kernel_vsyscall'.  This most
likely worked by accident: the linker script entry defines a symbol
associated with an address as opposed to an alias for the real
dynamic symbol __kernel_vsyscall.  That caused ld to relocate the
reference at link time instead of leaving an interposable dynamic
relocation.  Since the VDSO32_vsyscall hack is no longer needed, I
now use 'call __kernel_vsyscall', and I added -Bsymbolic to make it
work.  vdso2c will generate an error and abort the build if the
resulting image contains any dynamic relocations, so we won't
silently generate bad vdso images.

(Dynamic relocations are a problem because nothing will even attempt
to relocate the vdso.)

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/2c4fcf45524162a34d87fdda1eb046b2a5cecee7.1399317206.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-05-05 13:18:51 -07:00
Linus Torvalds
12f2bbd609 Merge branch 'x86-asmlinkage-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 asmlinkage (LTO) changes from Peter Anvin:
 "This patchset adds more infrastructure for link time optimization
  (LTO).

  This patchset was pulled into my tree late because of a
  miscommunication (part of the patchset was picked up by other
  maintainers).  However, the patchset is strictly build-related and
  seems to be okay in testing"

* 'x86-asmlinkage-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, asmlinkage, xen: Fix type of NMI
  x86, asmlinkage, xen, kvm: Make {xen,kvm}_lock_spinning global and visible
  x86: Use inline assembler instead of global register variable to get sp
  x86, asmlinkage, paravirt: Make paravirt thunks global
  x86, asmlinkage, paravirt: Don't rely on local assembler labels
  x86, asmlinkage, lguest: Fix C functions used by inline assembler
2014-01-30 18:15:32 -08:00
Andi Kleen
07ba06d9d2 x86, asmlinkage, xen: Fix type of NMI
LTO requires consistent types of symbols over all files.

So "nmi" cannot be declared as a char [] here, need to use the
correct function type.

Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1382458079-24450-8-git-send-email-andi@firstfloor.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-01-29 22:17:18 -08:00
Mukesh Rathor
9103bb0f82 xen/pvh: Update E820 to work with PVH (v2)
In xen_add_extra_mem() we can skip updating P2M as it's managed
by Xen. PVH maps the entire IO space, but only RAM pages need
to be repopulated.

Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2014-01-06 10:44:13 -05:00
Mukesh Rathor
d285d68314 xen/pvh: Early bootup changes in PV code (v4).
We don't use the filtering that 'xen_cpuid' is doing
because the hypervisor treats 'XEN_EMULATE_PREFIX' as
an invalid instruction. This means that all of the filtering
will have to be done in the hypervisor/toolstack.

Without the filtering we expose to the guest the:

 - cpu topology (sockets, cores, etc);
 - the APERF (which the generic scheduler likes to
    use), see  5e62625420
    "xen/setup: filter APERFMPERF cpuid feature out"
 - and the inability to figure out whether MWAIT_LEAF
   should be exposed or not. See
   df88b2d96e
   "xen/enlighten: Disable MWAIT_LEAF so that acpi-pad won't be loaded."
 - x2apic, see  4ea9b9aca9
   "xen: mask x2APIC feature in PV"

We also check for vector callback early on, as it is a required
feature. PVH also runs at default kernel IOPL.

Finally, pure PV settings are moved to a separate function that are
only called for pure PV, ie, pv with pvmmu. They are also #ifdef
with CONFIG_XEN_PVMMU.

Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2014-01-06 10:43:59 -05:00
Paul Gortmaker
3b284bde70 xen: delete new instances of added __cpuinit
commit 6efa20e49b
("xen: Support 64-bit PV guest receiving NMIs") and
commit cd9151e26d
( "xen/balloon: set a mapping for ballooned out pages")
added new instances of __cpuinit usage.

We removed this a couple versions ago; we now want to remove
the compat no-op stubs.  Introducing new users is not what
we want to see at this point in time, as it will break once
the stubs are gone.

Cc: Konrad Rzeszutek Wilk <konrad@kernel.org>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-11-08 15:13:16 -05:00
Linus Torvalds
cf39c8e535 Features:
- Xen Trusted Platform Module (TPM) frontend driver - with the backend in MiniOS.
  - Scalability improvements in event channel.
  - Two extra Xen co-maintainers (David, Boris) and one going away (Jeremy)
 Bug-fixes:
  - Make the 1:1 mapping work during early bootup on selective regions.
  - Add scratch page to balloon driver to deal with unexpected code still holding
    on stale pages.
  - Allow NMIs on PV guests (64-bit only)
  - Remove unnecessary TLB flush in M2P code.
  - Fixes duplicate callbacks in Xen granttable code.
  - Fixes in PRIVCMD_MMAPBATCH ioctls to allow retries
  - Fix for events being lost due to rescheduling on different VCPUs.
  - More documentation.
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Merge tag 'stable/for-linus-3.12-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull Xen updates from Konrad Rzeszutek Wilk:
 "A couple of features and a ton of bug-fixes.  There is also some
  maintership changes.  Jeremy is enjoying the full-time work at the
  startup and as much as he would love to help - he can't find the time.
  I have a bunch of other things that I promised to work on - paravirt
  diet, get SWIOTLB working everywhere, etc, but haven't been able to
  find the time.

  As such both David Vrabel and Boris Ostrovsky have graciously
  volunteered to help with the maintership role.  They will keep the lid
  on regressions, bug-fixes, etc.  I will be in the background to help -
  but eventually there will be less of me doing the Xen GIT pulls and
  more of them.  Stefano is still doing the ARM/ARM64 and will continue
  on doing so.

  Features:
   - Xen Trusted Platform Module (TPM) frontend driver - with the
     backend in MiniOS.
   - Scalability improvements in event channel.
   - Two extra Xen co-maintainers (David, Boris) and one going away (Jeremy)

  Bug-fixes:
   - Make the 1:1 mapping work during early bootup on selective regions.
   - Add scratch page to balloon driver to deal with unexpected code
     still holding on stale pages.
   - Allow NMIs on PV guests (64-bit only)
   - Remove unnecessary TLB flush in M2P code.
   - Fixes duplicate callbacks in Xen granttable code.
   - Fixes in PRIVCMD_MMAPBATCH ioctls to allow retries
   - Fix for events being lost due to rescheduling on different VCPUs.
   - More documentation"

* tag 'stable/for-linus-3.12-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (23 commits)
  hvc_xen: Remove unnecessary __GFP_ZERO from kzalloc
  drivers/xen-tpmfront: Fix compile issue with missing option.
  xen/balloon: don't set P2M entry for auto translated guest
  xen/evtchn: double free on error
  Xen: Fix retry calls into PRIVCMD_MMAPBATCH*.
  xen/pvhvm: Initialize xen panic handler for PVHVM guests
  xen/m2p: use GNTTABOP_unmap_and_replace to reinstate the original mapping
  xen: fix ARM build after 6efa20e4
  MAINTAINERS: Remove Jeremy from the Xen subsystem.
  xen/events: document behaviour when scanning the start word for events
  x86/xen: during early setup, only 1:1 map the ISA region
  x86/xen: disable premption when enabling local irqs
  swiotlb-xen: replace dma_length with sg_dma_len() macro
  swiotlb: replace dma_length with sg_dma_len() macro
  xen/balloon: set a mapping for ballooned out pages
  xen/evtchn: improve scalability by using per-user locks
  xen/p2m: avoid unneccesary TLB flush in m2p_remove_override()
  MAINTAINERS: Add in two extra co-maintainers of the Xen tree.
  MAINTAINERS: Update the Xen subsystem's with proper mailing list.
  xen: replace strict_strtoul() with kstrtoul()
  ...
2013-09-04 17:45:39 -07:00
Linus Torvalds
d936d2d452 Bug-fixes:
- On ARM did not have balanced calls to get/put_cpu.
  - Fix to make tboot + Xen + Linux correctly.
  - Fix events VCPU binding issues.
  - Fix a vCPU online race where IPIs are sent to not-yet-online vCPU.
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Merge tag 'stable/for-linus-3.11-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull Xen bug-fixes from Konrad Rzeszutek Wilk:
 - On ARM did not have balanced calls to get/put_cpu.
 - Fix to make tboot + Xen + Linux correctly.
 - Fix events VCPU binding issues.
 - Fix a vCPU online race where IPIs are sent to not-yet-online vCPU.

* tag 'stable/for-linus-3.11-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/smp: initialize IPI vectors before marking CPU online
  xen/events: mask events when changing their VCPU binding
  xen/events: initialize local per-cpu mask for all possible events
  x86/xen: do not identity map UNUSABLE regions in the machine E820
  xen/arm: missing put_cpu in xen_percpu_init
2013-08-21 16:38:33 -07:00
David Vrabel
e201bfcc5c x86/xen: during early setup, only 1:1 map the ISA region
During early setup, when the reserved regions and MMIO holes are being
setup as 1:1 in the p2m, clear any mappings instead of making them 1:1
(execept for the ISA region which is expected to be mapped).

This fixes a regression introduced in 3.5 by 83d51ab473 (xen/setup:
update VA mapping when releasing memory during setup) which caused
hosts with tboot to fail to boot.

tboot marks a region in the e820 map as unusable and the dom0 kernel
would attempt to map this region and Xen does not permit unusable
regions to be mapped by guests.

(XEN)  0000000000000000 - 0000000000060000 (usable)
(XEN)  0000000000060000 - 0000000000068000 (reserved)
(XEN)  0000000000068000 - 000000000009e000 (usable)
(XEN)  0000000000100000 - 0000000000800000 (usable)
(XEN)  0000000000800000 - 0000000000972000 (unusable)

tboot marked this region as unusable.

(XEN)  0000000000972000 - 00000000cf200000 (usable)
(XEN)  00000000cf200000 - 00000000cf38f000 (reserved)
(XEN)  00000000cf38f000 - 00000000cf3ce000 (ACPI data)
(XEN)  00000000cf3ce000 - 00000000d0000000 (reserved)
(XEN)  00000000e0000000 - 00000000f0000000 (reserved)
(XEN)  00000000fe000000 - 0000000100000000 (reserved)
(XEN)  0000000100000000 - 0000000630000000 (usable)

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-08-20 10:12:29 -04:00
David Vrabel
3bc38cbceb x86/xen: do not identity map UNUSABLE regions in the machine E820
If there are UNUSABLE regions in the machine memory map, dom0 will
attempt to map them 1:1 which is not permitted by Xen and the kernel
will crash.

There isn't anything interesting in the UNUSABLE region that the dom0
kernel needs access to so we can avoid making the 1:1 mapping and
treat it as RAM.

We only do this for dom0, as that is where tboot case shows up.
A PV domU could have an UNUSABLE region in its pseudo-physical map
and would need to be handled in another patch.

This fixes a boot failure on hosts with tboot.

tboot marks a region in the e820 map as unusable and the dom0 kernel
would attempt to map this region and Xen does not permit unusable
regions to be mapped by guests.

  (XEN)  0000000000000000 - 0000000000060000 (usable)
  (XEN)  0000000000060000 - 0000000000068000 (reserved)
  (XEN)  0000000000068000 - 000000000009e000 (usable)
  (XEN)  0000000000100000 - 0000000000800000 (usable)
  (XEN)  0000000000800000 - 0000000000972000 (unusable)

tboot marked this region as unusable.

  (XEN)  0000000000972000 - 00000000cf200000 (usable)
  (XEN)  00000000cf200000 - 00000000cf38f000 (reserved)
  (XEN)  00000000cf38f000 - 00000000cf3ce000 (ACPI data)
  (XEN)  00000000cf3ce000 - 00000000d0000000 (reserved)
  (XEN)  00000000e0000000 - 00000000f0000000 (reserved)
  (XEN)  00000000fe000000 - 0000000100000000 (reserved)
  (XEN)  0000000100000000 - 0000000630000000 (usable)

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
[v1: Altered the patch and description with domU's with UNUSABLE regions]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-08-20 09:46:06 -04:00
Konrad Rzeszutek Wilk
6efa20e49b xen: Support 64-bit PV guest receiving NMIs
This is based on a patch that Zhenzhong Duan had sent - which
was missing some of the remaining pieces. The kernel has the
logic to handle Xen-type-exceptions using the paravirt interface
in the assembler code (see PARAVIRT_ADJUST_EXCEPTION_FRAME -
pv_irq_ops.adjust_exception_frame and and INTERRUPT_RETURN -
pv_cpu_ops.iret).

That means the nmi handler (and other exception handlers) use
the hypervisor iret.

The other changes that would be neccessary for this would
be to translate the NMI_VECTOR to one of the entries on the
ipi_vector and make xen_send_IPI_mask_allbutself use different
events.

Fortunately for us commit 1db01b4903
(xen: Clean up apic ipi interface) implemented this and we piggyback
on the cleanup such that the apic IPI interface will pass the right
vector value for NMI.

With this patch we can trigger NMIs within a PV guest (only tested
x86_64).

For this to work with normal PV guests (not initial domain)
we need the domain to be able to use the APIC ops - they are
already implemented to use the Xen event channels. For that
to be turned on in a PV domU we need to remove the masking
of X86_FEATURE_APIC.

Incidentally that means kgdb will also now work within
a PV guest without using the 'nokgdbroundup' workaround.

Note that the 32-bit version is different and this patch
does not enable that.

CC: Lisa Nguyen <lisa@xenapiadmin.com>
CC: Ben Guthro <benjamin.guthro@citrix.com>
CC: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[v1: Fixed up per David Vrabel comments]
Reviewed-by: Ben Guthro <benjamin.guthro@citrix.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
2013-08-09 10:55:47 -04:00
Paul Gortmaker
148f9bb877 x86: delete __cpuinit usage from all x86 files
The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications.  For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.

After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out.  Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.

Note that some harmless section mismatch warnings may result, since
notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
are flagged as __cpuinit  -- so if we remove the __cpuinit from
arch specific callers, we will also get section mismatch warnings.
As an intermediate step, we intend to turn the linux/init.h cpuinit
content into no-ops as early as possible, since that will get rid
of these warnings.  In any case, they are temporary and harmless.

This removes all the arch/x86 uses of the __cpuinit macros from
all C files.  x86 only had the one __CPUINIT used in assembly files,
and it wasn't paired off with a .previous or a __FINIT, so we can
delete it directly w/o any corresponding additional change there.

[1] https://lkml.org/lkml/2013/5/20/589

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2013-07-14 19:36:56 -04:00
Len Brown
27be457000 x86 idle: remove 32-bit-only "no-hlt" parameter, hlt_works_ok flag
Remove 32-bit x86 a cmdline param "no-hlt",
and the cpuinfo_x86.hlt_works_ok that it sets.

If a user wants to avoid HLT, then "idle=poll"
is much more useful, as it avoids invocation of HLT
in idle, while "no-hlt" failed to do so.

Indeed, hlt_works_ok was consulted in only 3 places.

First, in /proc/cpuinfo where "hlt_bug yes"
would be printed if and only if the user booted
the system with "no-hlt" -- as there was no other code
to set that flag.

Second, check_hlt() would not invoke halt() if "no-hlt"
were on the cmdline.

Third, it was consulted in stop_this_cpu(), which is invoked
by native_machine_halt()/reboot_interrupt()/smp_stop_nmi_callback() --
all cases where the machine is being shutdown/reset.
The flag was not consulted in the more frequently invoked
play_dead()/hlt_play_dead() used in processor offline and suspend.

Since Linux-3.0 there has been a run-time notice upon "no-hlt" invocations
indicating that it would be removed in 2012.

Signed-off-by: Len Brown <len.brown@intel.com>
Cc: x86@kernel.org
2013-02-10 03:32:22 -05:00