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Author SHA1 Message Date
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
Len Brown 6a377ddc4e xen idle: make xen-specific macro xen-specific
This macro is only invoked by Xen,
so make its definition specific to Xen.

> set_pm_idle_to_default()
< xen_set_default_idle()

Signed-off-by: Len Brown <len.brown@intel.com>
Cc: xen-devel@lists.xensource.com
2013-02-10 01:06:34 -05:00
Linus Torvalds 56d92aa5cf Features:
* When hotplugging PCI devices in a PV guest we can allocate Xen-SWIOTLB later.
  * Cleanup Xen SWIOTLB.
  * Support pages out grants from HVM domains in the backends.
  * Support wild cards in xen-pciback.hide=(BDF) arguments.
  * Update grant status updates with upstream hypervisor.
  * Boot PV guests with more than 128GB.
  * Cleanup Xen MMU code/add comments.
  * Obtain XENVERS using a preferred method.
  * Lay out generic changes to support Xen ARM.
  * Allow privcmd ioctl for HVM (used to do only PV).
  * Do v2 of mmap_batch for privcmd ioctls.
  * If hypervisor saves the LED keyboard light - we will now instruct the kernel
    about its state.
 Fixes:
  * More fixes to Xen PCI backend for various calls/FLR/etc.
  * With more than 4GB in a 64-bit PV guest disable native SWIOTLB.
  * Fix up smatch warnings.
  * Fix up various return values in privmcmd and mm.
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Merge tag 'stable/for-linus-3.7-x86-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen

Pull Xen update from Konrad Rzeszutek Wilk:
 "Features:
   - When hotplugging PCI devices in a PV guest we can allocate
     Xen-SWIOTLB later.
   - Cleanup Xen SWIOTLB.
   - Support pages out grants from HVM domains in the backends.
   - Support wild cards in xen-pciback.hide=(BDF) arguments.
   - Update grant status updates with upstream hypervisor.
   - Boot PV guests with more than 128GB.
   - Cleanup Xen MMU code/add comments.
   - Obtain XENVERS using a preferred method.
   - Lay out generic changes to support Xen ARM.
   - Allow privcmd ioctl for HVM (used to do only PV).
   - Do v2 of mmap_batch for privcmd ioctls.
   - If hypervisor saves the LED keyboard light - we will now instruct
     the kernel about its state.
  Fixes:
   - More fixes to Xen PCI backend for various calls/FLR/etc.
   - With more than 4GB in a 64-bit PV guest disable native SWIOTLB.
   - Fix up smatch warnings.
   - Fix up various return values in privmcmd and mm."

* tag 'stable/for-linus-3.7-x86-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: (48 commits)
  xen/pciback: Restore the PCI config space after an FLR.
  xen-pciback: properly clean up after calling pcistub_device_find()
  xen/vga: add the xen EFI video mode support
  xen/x86: retrieve keyboard shift status flags from hypervisor.
  xen/gndev: Xen backend support for paged out grant targets V4.
  xen-pciback: support wild cards in slot specifications
  xen/swiotlb: Fix compile warnings when using plain integer instead of NULL pointer.
  xen/swiotlb: Remove functions not needed anymore.
  xen/pcifront: Use Xen-SWIOTLB when initting if required.
  xen/swiotlb: For early initialization, return zero on success.
  xen/swiotlb: Use the swiotlb_late_init_with_tbl to init Xen-SWIOTLB late when PV PCI is used.
  xen/swiotlb: Move the error strings to its own function.
  xen/swiotlb: Move the nr_tbl determination in its own function.
  xen/arm: compile and run xenbus
  xen: resynchronise grant table status codes with upstream
  xen/privcmd: return -EFAULT on error
  xen/privcmd: Fix mmap batch ioctl error status copy back.
  xen/privcmd: add PRIVCMD_MMAPBATCH_V2 ioctl
  xen/mm: return more precise error from xen_remap_domain_range()
  xen/mmu: If the revector fails, don't attempt to revector anything else.
  ...
2012-10-02 22:09:10 -07:00
Konrad Rzeszutek Wilk 8d54db795d xen/boot: Disable NUMA for PV guests.
The hypervisor is in charge of allocating the proper "NUMA" memory
and dealing with the CPU scheduler to keep them bound to the proper
NUMA node. The PV guests (and PVHVM) have no inkling of where they
run and do not need to know that right now. In the future we will
need to inject NUMA configuration data (if a guest spans two or more
NUMA nodes) so that the kernel can make the right choices. But those
patches are not yet present.

In the meantime, disable the NUMA capability in the PV guest, which
also fixes a bootup issue. Andre says:

"we see Dom0 crashes due to the kernel detecting the NUMA topology not
by ACPI, but directly from the northbridge (CONFIG_AMD_NUMA).

This will detect the actual NUMA config of the physical machine, but
will crash about the mismatch with Dom0's virtual memory. Variation of
the theme: Dom0 sees what it's not supposed to see.

This happens with the said config option enabled and on a machine where
this scanning is still enabled (K8 and Fam10h, not Bulldozer class)

We have this dump then:
NUMA: Warning: node ids are out of bound, from=-1 to=-1 distance=10
Scanning NUMA topology in Northbridge 24
Number of physical nodes 4
Node 0 MemBase 0000000000000000 Limit 0000000040000000
Node 1 MemBase 0000000040000000 Limit 0000000138000000
Node 2 MemBase 0000000138000000 Limit 00000001f8000000
Node 3 MemBase 00000001f8000000 Limit 0000000238000000
Initmem setup node 0 0000000000000000-0000000040000000
  NODE_DATA [000000003ffd9000 - 000000003fffffff]
Initmem setup node 1 0000000040000000-0000000138000000
  NODE_DATA [0000000137fd9000 - 0000000137ffffff]
Initmem setup node 2 0000000138000000-00000001f8000000
  NODE_DATA [00000001f095e000 - 00000001f0984fff]
Initmem setup node 3 00000001f8000000-0000000238000000
Cannot find 159744 bytes in node 3
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffff81d220e6>] __alloc_bootmem_node+0x43/0x96
Pid: 0, comm: swapper Not tainted 3.3.6 #1 AMD Dinar/Dinar
RIP: e030:[<ffffffff81d220e6>]  [<ffffffff81d220e6>] __alloc_bootmem_node+0x43/0x96
.. snip..
  [<ffffffff81d23024>] sparse_early_usemaps_alloc_node+0x64/0x178
  [<ffffffff81d23348>] sparse_init+0xe4/0x25a
  [<ffffffff81d16840>] paging_init+0x13/0x22
  [<ffffffff81d07fbb>] setup_arch+0x9c6/0xa9b
  [<ffffffff81683954>] ? printk+0x3c/0x3e
  [<ffffffff81d01a38>] start_kernel+0xe5/0x468
  [<ffffffff81d012cf>] x86_64_start_reservations+0xba/0xc1
  [<ffffffff81007153>] ? xen_setup_runstate_info+0x2c/0x36
  [<ffffffff81d050ee>] xen_start_kernel+0x565/0x56c
"

so we just disable NUMA scanning by setting numa_off=1.

CC: stable@vger.kernel.org
Reported-and-Tested-by: Andre Przywara <andre.przywara@amd.com>
Acked-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-09-24 08:47:20 -04:00
Konrad Rzeszutek Wilk 98104c3480 Merge branch 'stable/128gb.v5.1' into stable/for-linus-3.7
* stable/128gb.v5.1:
  xen/mmu: If the revector fails, don't attempt to revector anything else.
  xen/p2m: When revectoring deal with holes in the P2M array.
  xen/mmu: Release just the MFN list, not MFN list and part of pagetables.
  xen/mmu: Remove from __ka space PMD entries for pagetables.
  xen/mmu: Copy and revector the P2M tree.
  xen/p2m: Add logic to revector a P2M tree to use __va leafs.
  xen/mmu: Recycle the Xen provided L4, L3, and L2 pages
  xen/mmu: For 64-bit do not call xen_map_identity_early
  xen/mmu: use copy_page instead of memcpy.
  xen/mmu: Provide comments describing the _ka and _va aliasing issue
  xen/mmu: The xen_setup_kernel_pagetable doesn't need to return anything.
  Revert "xen/x86: Workaround 64-bit hypervisor and 32-bit initial domain." and "xen/x86: Use memblock_reserve for sensitive areas."
  xen/x86: Workaround 64-bit hypervisor and 32-bit initial domain.
  xen/x86: Use memblock_reserve for sensitive areas.
  xen/p2m: Fix the comment describing the P2M tree.

Conflicts:
	arch/x86/xen/mmu.c

The pagetable_init is the old xen_pagetable_setup_done and xen_pagetable_setup_start
rolled in one.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-09-12 11:18:57 -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 c96aae1f7f xen/setup: Fix one-off error when adding for-balloon PFNs to the P2M.
When we are finished with return PFNs to the hypervisor, then
populate it back, and also mark the E820 MMIO and E820 gaps
as IDENTITY_FRAMEs, we then call P2M to set areas that can
be used for ballooning. We were off by one, and ended up
over-writting a P2M entry that most likely was an IDENTITY_FRAME.
For example:

1-1 mapping on 40000->40200
1-1 mapping on bc558->bc5ac
1-1 mapping on bc5b4->bc8c5
1-1 mapping on bc8c6->bcb7c
1-1 mapping on bcd00->100000
Released 614 pages of unused memory
Set 277889 page(s) to 1-1 mapping
Populating 40200-40466 pfn range: 614 pages added

=> here we set from 40466 up to bc559 P2M tree to be
INVALID_P2M_ENTRY. We should have done it up to bc558.

The end result is that if anybody is trying to construct
a PTE for PFN bc558 they end up with ~PAGE_PRESENT.

CC: stable@vger.kernel.org
Reported-by-and-Tested-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-08-23 10:14:52 -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
zhenzhong.duan c3d93f8801 xen: populate correct number of pages when across mem boundary (v2)
When populate pages across a mem boundary at bootup, the page count
populated isn't correct. This is due to mem populated to non-mem
region and ignored.

Pfn range is also wrongly aligned when mem boundary isn't page aligned.

For a dom0 booted with dom_mem=3368952K(0xcd9ff000-4k) dmesg diff is:
 [    0.000000] Freeing 9e-100 pfn range: 98 pages freed
 [    0.000000] 1-1 mapping on 9e->100
 [    0.000000] 1-1 mapping on cd9ff->100000
 [    0.000000] Released 98 pages of unused memory
 [    0.000000] Set 206435 page(s) to 1-1 mapping
-[    0.000000] Populating cd9fe-cda00 pfn range: 1 pages added
+[    0.000000] Populating cd9fe-cd9ff pfn range: 1 pages added
+[    0.000000] Populating 100000-100061 pfn range: 97 pages added
 [    0.000000] BIOS-provided physical RAM map:
 [    0.000000] Xen: 0000000000000000 - 000000000009e000 (usable)
 [    0.000000] Xen: 00000000000a0000 - 0000000000100000 (reserved)
 [    0.000000] Xen: 0000000000100000 - 00000000cd9ff000 (usable)
 [    0.000000] Xen: 00000000cd9ffc00 - 00000000cda53c00 (ACPI NVS)
...
 [    0.000000] Xen: 0000000100000000 - 0000000100061000 (usable)
 [    0.000000] Xen: 0000000100061000 - 000000012c000000 (unusable)
...
 [    0.000000] MEMBLOCK configuration:
...
-[    0.000000]  reserved[0x4]       [0x000000cd9ff000-0x000000cd9ffbff], 0xc00 bytes
-[    0.000000]  reserved[0x5]       [0x00000100000000-0x00000100060fff], 0x61000 bytes

Related xen memory layout:
(XEN) Xen-e820 RAM map:
(XEN)  0000000000000000 - 000000000009ec00 (usable)
(XEN)  00000000000f0000 - 0000000000100000 (reserved)
(XEN)  0000000000100000 - 00000000cd9ffc00 (usable)

Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com>
[v2: If xen_do_chunk fail(populate), abort this chunk and any others]
Suggested by David, thanks.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-07-19 15:52:06 -04:00
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
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
Konrad Rzeszutek Wilk 48cdd8287f xen/cpufreq: Disable the cpu frequency scaling drivers from loading.
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: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[v2: Fix compile error spotted by Benjamin Schweikert <b.schweikert@googlemail.com>]
2012-03-20 15:31:38 -04:00
Konrad Rzeszutek Wilk cc7335b2f6 xen/setup/pm/acpi: Remove the call to boot_option_idle_override.
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: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-03-10 12:44:09 -05:00
Ingo Molnar 45aa0663cc Merge branch 'memblock-kill-early_node_map' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc into core/memblock 2011-12-20 12:14:26 +01:00
Linus Torvalds 42ebfc61cf Merge branch 'stable/for-linus-fixes-3.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
* 'stable/for-linus-fixes-3.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/swiotlb: Use page alignment for early buffer allocation.
  xen: only limit memory map to maximum reservation for domain 0.
2011-12-15 10:52:40 -08:00
Ian Campbell d3db728125 xen: only limit memory map to maximum reservation for domain 0.
d312ae878b "xen: use maximum reservation to limit amount of usable RAM"
clamped the total amount of RAM to the current maximum reservation. This is
correct for dom0 but is not correct for guest domains. In order to boot a guest
"pre-ballooned" (e.g. with memory=1G but maxmem=2G) in order to allow for
future memory expansion the guest must derive max_pfn from the e820 provided by
the toolstack and not the current maximum reservation (which can reflect only
the current maximum, not the guest lifetime max). The existing algorithm
already behaves this correctly if we do not artificially limit the maximum
number of pages for the guest case.

For a guest booted with maxmem=512, memory=128 this results in:
 [    0.000000] BIOS-provided physical RAM map:
 [    0.000000]  Xen: 0000000000000000 - 00000000000a0000 (usable)
 [    0.000000]  Xen: 00000000000a0000 - 0000000000100000 (reserved)
-[    0.000000]  Xen: 0000000000100000 - 0000000008100000 (usable)
-[    0.000000]  Xen: 0000000008100000 - 0000000020800000 (unusable)
+[    0.000000]  Xen: 0000000000100000 - 0000000020800000 (usable)
...
 [    0.000000] NX (Execute Disable) protection: active
 [    0.000000] DMI not present or invalid.
 [    0.000000] e820 update range: 0000000000000000 - 0000000000010000 (usable) ==> (reserved)
 [    0.000000] e820 remove range: 00000000000a0000 - 0000000000100000 (usable)
-[    0.000000] last_pfn = 0x8100 max_arch_pfn = 0x1000000
+[    0.000000] last_pfn = 0x20800 max_arch_pfn = 0x1000000
 [    0.000000] initial memory mapped : 0 - 027ff000
 [    0.000000] Base memory trampoline at [c009f000] 9f000 size 4096
-[    0.000000] init_memory_mapping: 0000000000000000-0000000008100000
-[    0.000000]  0000000000 - 0008100000 page 4k
-[    0.000000] kernel direct mapping tables up to 8100000 @ 27bb000-27ff000
+[    0.000000] init_memory_mapping: 0000000000000000-0000000020800000
+[    0.000000]  0000000000 - 0020800000 page 4k
+[    0.000000] kernel direct mapping tables up to 20800000 @ 26f8000-27ff000
 [    0.000000] xen: setting RW the range 27e8000 - 27ff000
 [    0.000000] 0MB HIGHMEM available.
-[    0.000000] 129MB LOWMEM available.
-[    0.000000]   mapped low ram: 0 - 08100000
-[    0.000000]   low ram: 0 - 08100000
+[    0.000000] 520MB LOWMEM available.
+[    0.000000]   mapped low ram: 0 - 20800000
+[    0.000000]   low ram: 0 - 20800000

With this change "xl mem-set <domain> 512M" will successfully increase the
guest RAM (by reducing the balloon).

There is no change for dom0.

Reported-and-Tested-by:  George Shuklin <george.shuklin@gmail.com>
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: stable@kernel.org
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-12-15 11:24:02 -05:00
Konrad Rzeszutek Wilk e5fd47bfab xen/pm_idle: Make pm_idle be default_idle under Xen.
The idea behind commit d91ee5863b ("cpuidle: replace xen access to x86
pm_idle and default_idle") was to have one call - disable_cpuidle()
which would make pm_idle not be molested by other code.  It disallows
cpuidle_idle_call to be set to pm_idle (which is excellent).

But in the select_idle_routine() and idle_setup(), the pm_idle can still
be set to either: amd_e400_idle, mwait_idle or default_idle.  This
depends on some CPU flags (MWAIT) and in AMD case on the type of CPU.

In case of mwait_idle we can hit some instances where the hypervisor
(Amazon EC2 specifically) sets the MWAIT and we get:

  Brought up 2 CPUs
  invalid opcode: 0000 [#1] SMP

  Pid: 0, comm: swapper Not tainted 3.1.0-0.rc6.git0.3.fc16.x86_64 #1
  RIP: e030:[<ffffffff81015d1d>]  [<ffffffff81015d1d>] mwait_idle+0x6f/0xb4
  ...
  Call Trace:
   [<ffffffff8100e2ed>] cpu_idle+0xae/0xe8
   [<ffffffff8149ee78>] cpu_bringup_and_idle+0xe/0x10
  RIP  [<ffffffff81015d1d>] mwait_idle+0x6f/0xb4
   RSP <ffff8801d28ddf10>

In the case of amd_e400_idle we don't get so spectacular crashes, but we
do end up making an MSR which is trapped in the hypervisor, and then
follow it up with a yield hypercall.  Meaning we end up going to
hypervisor twice instead of just once.

The previous behavior before v3.0 was that pm_idle was set to
default_idle regardless of select_idle_routine/idle_setup.

We want to do that, but only for one specific case: Xen.  This patch
does that.

Fixes RH BZ #739499 and Ubuntu #881076
Reported-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-12-03 10:49:58 -08:00
Tejun Heo d4bbf7e775 Merge branch 'master' into x86/memblock
Conflicts & resolutions:

* arch/x86/xen/setup.c

	dc91c728fd "xen: allow extra memory to be in multiple regions"
	24aa07882b "memblock, x86: Replace memblock_x86_reserve/free..."

	conflicted on xen_add_extra_mem() updates.  The resolution is
	trivial as the latter just want to replace
	memblock_x86_reserve_range() with memblock_reserve().

* drivers/pci/intel-iommu.c

	166e9278a3 "x86/ia64: intel-iommu: move to drivers/iommu/"
	5dfe8660a3 "bootmem: Replace work_with_active_regions() with..."

	conflicted as the former moved the file under drivers/iommu/.
	Resolved by applying the chnages from the latter on the moved
	file.

* mm/Kconfig

	6661672053 "memblock: add NO_BOOTMEM config symbol"
	c378ddd53f "memblock, x86: Make ARCH_DISCARD_MEMBLOCK a config option"

	conflicted trivially.  Both added config options.  Just
	letting both add their own options resolves the conflict.

* mm/memblock.c

	d1f0ece6cd "mm/memblock.c: small function definition fixes"
	ed7b56a799 "memblock: Remove memblock_memory_can_coalesce()"

	confliected.  The former updates function removed by the
	latter.  Resolution is trivial.

Signed-off-by: Tejun Heo <tj@kernel.org>
2011-11-28 09:46:22 -08:00
David Vrabel f3f436e33b xen: release all pages within 1-1 p2m mappings
In xen_memory_setup() all reserved regions and gaps are set to an
identity (1-1) p2m mapping.  If an available page has a PFN within one
of these 1-1 mappings it will become inaccessible (as it MFN is lost)
so release them before setting up the mapping.

This can make an additional 256 MiB or more of RAM available
(depending on the size of the reserved regions in the memory map) if
the initial pages overlap with reserved regions.

The 1:1 p2m mappings are also extended to cover partial pages.  This
fixes an issue with (for example) systems with a BIOS that puts the
DMI tables in a reserved region that begins on a non-page boundary.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-09-29 11:12:15 -04:00
David Vrabel dc91c728fd xen: allow extra memory to be in multiple regions
Allow the extra memory (used by the balloon driver) to be in multiple
regions (typically two regions, one for low memory and one for high
memory).  This allows the balloon driver to increase the number of
available low pages (if the initial number if pages is small).

As a side effect, the algorithm for building the e820 memory map is
simpler and more obviously correct as the map supplied by the
hypervisor is (almost) used as is (in particular, all reserved regions
and gaps are preserved).  Only RAM regions are altered and RAM regions
above max_pfn + extra_pages are marked as unused (the region is split
in two if necessary).

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-09-29 11:12:10 -04:00
David Vrabel 8b5d44a5ac xen: allow balloon driver to use more than one memory region
Allow the xen balloon driver to populate its list of extra pages from
more than one region of memory.  This will allow platforms to provide
(for example) a region of low memory and a region of high memory.

The maximum possible number of extra regions is 128 (== E820MAX) which
is quite large so xen_extra_mem is placed in __initdata.  This is safe
as both xen_memory_setup() and balloon_init() are in __init.

The balloon regions themselves are not altered (i.e., there is still
only the one region).

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-09-29 11:12:10 -04:00
David Vrabel aa24411b67 xen/balloon: account for pages released during memory setup
In xen_memory_setup() pages that occur in gaps in the memory map are
released back to Xen.  This reduces the domain's current page count in
the hypervisor.  The Xen balloon driver does not correctly decrease
its initial current_pages count to reflect this.  If 'delta' pages are
released and the target is adjusted the resulting reservation is
always 'delta' less than the requested target.

This affects dom0 if the initial allocation of pages overlaps the PCI
memory region but won't affect most domU guests that have been setup
with pseudo-physical memory maps that don't have gaps.

Fix this by accouting for the released pages when starting the balloon
driver.

If the domain's targets are managed by xapi, the domain may eventually
run out of memory and die because xapi currently gets its target
calculations wrong and whenever it is restarted it always reduces the
target by 'delta'.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-09-29 11:12:09 -04:00
Linus Torvalds abbe0d3c26 Merge branch 'stable/bug.fixes' of git://oss.oracle.com/git/kwilk/xen
* 'stable/bug.fixes' of git://oss.oracle.com/git/kwilk/xen:
  xen/i386: follow-up to "replace order-based range checking of M2P table by linear one"
  xen/irq: Alter the locking to use a mutex instead of a spinlock.
  xen/e820: if there is no dom0_mem=, don't tweak extra_pages.
  xen: disable PV spinlocks on HVM
2011-09-16 11:28:11 -07:00
David Vrabel e3b73c4a25 xen/e820: if there is no dom0_mem=, don't tweak extra_pages.
The patch "xen: use maximum reservation to limit amount of usable RAM"
(d312ae878b) breaks machines that
do not use 'dom0_mem=' argument with:

reserve RAM buffer: 000000133f2e2000 - 000000133fffffff
(XEN) mm.c:4976:d0 Global bit is set to kernel page fffff8117e
(XEN) domain_crash_sync called from entry.S
(XEN) Domain 0 (vcpu#0) crashed on cpu#0:
...

The reason being that the last E820 entry is created using the
'extra_pages' (which is based on how many pages have been freed).
The mentioned git commit sets the initial value of 'extra_pages'
using a hypercall which returns the number of pages (if dom0_mem
has been used) or -1 otherwise. If the later we return with
MAX_DOMAIN_PAGES as basis for calculation:

    return min(max_pages, MAX_DOMAIN_PAGES);

and use it:

     extra_limit = xen_get_max_pages();
     if (extra_limit >= max_pfn)
             extra_pages = extra_limit - max_pfn;
     else
             extra_pages = 0;

which means we end up with extra_pages = 128GB in PFNs (33554432)
- 8GB in PFNs (2097152, on this specific box, can be larger or smaller),
and then we add that value to the E820 making it:

  Xen: 00000000ff000000 - 0000000100000000 (reserved)
  Xen: 0000000100000000 - 000000133f2e2000 (usable)

which is clearly wrong. It should look as so:

  Xen: 00000000ff000000 - 0000000100000000 (reserved)
  Xen: 0000000100000000 - 000000027fbda000 (usable)

Naturally this problem does not present itself if dom0_mem=max:X
is used.

CC: stable@kernel.org
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-09-13 10:17:32 -04:00
Linus Torvalds 1154526753 Merge branch 'stable/bug.fixes' of git://oss.oracle.com/git/kwilk/xen
* 'stable/bug.fixes' of git://oss.oracle.com/git/kwilk/xen:
  xen/smp: Warn user why they keel over - nosmp or noapic and what to use instead.
  xen: x86_32: do not enable iterrupts when returning from exception in interrupt context
  xen: use maximum reservation to limit amount of usable RAM
2011-09-07 07:46:48 -07:00
David Vrabel d312ae878b xen: use maximum reservation to limit amount of usable RAM
Use the domain's maximum reservation to limit the amount of extra RAM
for the memory balloon. This reduces the size of the pages tables and
the amount of reserved low memory (which defaults to about 1/32 of the
total RAM).

On a system with 8 GiB of RAM with the domain limited to 1 GiB the
kernel reports:

Before:

Memory: 627792k/4472000k available

After:

Memory: 549740k/11132224k available

A increase of about 76 MiB (~1.5% of the unused 7 GiB).  The reserved
low memory is also reduced from 253 MiB to 32 MiB.  The total
additional usable RAM is 329 MiB.

For dom0, this requires at patch to Xen ('x86: use 'dom0_mem' to limit
the number of pages for dom0') (c/s 23790)

CC: stable@kernel.org
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-09-01 09:41:40 -04:00
Linus Torvalds 45a05f9488 Merge branch 'stable/bug.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
* 'stable/bug.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/trace: Fix compile error when CONFIG_XEN_PRIVILEGED_GUEST is not set
  xen: Fix misleading WARN message at xen_release_chunk
  xen: Fix printk() format in xen/setup.c
  xen/tracing: it looks like we wanted CONFIG_FTRACE
  xen/self-balloon: Add dependency on tmem.
  xen/balloon: Fix compile errors - missing header files.
  xen/grant: Fix compile warning.
  xen/pciback: remove duplicated #include
2011-08-06 12:22:30 -07:00
Igor Mammedov 98f531da84 xen: Fix misleading WARN message at xen_release_chunk
WARN message should not complain
 "Failed to release memory %lx-%lx err=%d\n"
                           ^^^^^^^
about range when it fails to release just one page,
instead it should say what pfn is not freed.

In addition line:
 printk(KERN_INFO "xen_release_chunk: looking at area pfn %lx-%lx: "
 ...
 printk(KERN_CONT "%lu pages freed\n", len);
will be broken if WARN in between this line is fired. So fix it
by using a single printk for this.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-08-04 15:31:29 -04:00
Igor Mammedov 8f3c5883d8 xen: Fix printk() format in xen/setup.c
Use correct format specifier for unsigned long.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-08-04 15:31:28 -04:00
Len Brown d91ee5863b cpuidle: replace xen access to x86 pm_idle and default_idle
When a Xen Dom0 kernel boots on a hypervisor, it gets access
to the raw-hardware ACPI tables.  While it parses the idle tables
for the hypervisor's beneift, it uses HLT for its own idle.

Rather than have xen scribble on pm_idle and access default_idle,
have it simply disable_cpuidle() so acpi_idle will not load and
architecture default HLT will be used.

cc: xen-devel@lists.xensource.com
Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
2011-08-03 19:06:36 -04:00
Tejun Heo 24aa07882b memblock, x86: Replace memblock_x86_reserve/free_range() with generic ones
Other than sanity check and debug message, the x86 specific version of
memblock reserve/free functions are simple wrappers around the generic
versions - memblock_reserve/free().

This patch adds debug messages with caller identification to the
generic versions and replaces x86 specific ones and kills them.
arch/x86/include/asm/memblock.h and arch/x86/mm/memblock.c are empty
after this change and removed.

Signed-off-by: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/1310462166-31469-14-git-send-email-tj@kernel.org
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-07-14 11:47:53 -07:00
Konrad Rzeszutek Wilk acd049c6e9 xen/setup: Fix for incorrect xen_extra_mem_start.
The earlier attempts (24bdb0b62c)
at fixing this problem caused other problems to surface (PV guests
with no PCI passthrough would have SWIOTLB turned on - which meant
64MB of precious contingous DMA32 memory being eaten up per guest).
The problem was: "on xen we add an extra memory region at the end of
the e820, and on this particular machine this extra memory region
would start below 4g and cross over the 4g boundary:

[0xfee01000-0x192655000)

Unfortunately e820_end_of_low_ram_pfn does not expect an
e820 layout like that so it returns 4g, therefore initial_memory_mapping
will map [0 - 0x100000000), that is a memory range that includes some
reserved memory regions."

The memory range was the IOAPIC regions, and with the 1-1 mapping
turned on, it would map them as RAM, not as MMIO regions. This caused
the hypervisor to complain. Fortunately this is experienced only under
the initial domain so we guard for it.

Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-06-16 13:51:32 -04:00
Linus Torvalds e33ab8f275 Merge branches 'stable/irq', 'stable/p2m.bugfixes', 'stable/e820.bugfixes' and 'stable/mmu.bugfixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
* 'stable/irq' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen: do not clear and mask evtchns in __xen_evtchn_do_upcall

* 'stable/p2m.bugfixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/p2m: Create entries in the P2M_MFN trees's to track 1-1 mappings

* 'stable/e820.bugfixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/setup: Fix for incorrect xen_extra_mem_start initialization under 32-bit
  xen/setup: Ignore E820_UNUSABLE when setting 1-1 mappings.

* 'stable/mmu.bugfixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen mmu: fix a race window causing leave_mm BUG()
2011-05-19 16:14:58 -07:00
Daniel Kiper ae15a3b4d1 arch/x86/xen/setup: Cleanup code/data sections definitions
Cleanup code/data sections definitions
accordingly to include/linux/init.h.

Signed-off-by: Daniel Kiper <dkiper@net-space.pl>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-12 17:19:34 -04:00
Daniel Kiper 0f16d0dfcd xen/setup: Fix for incorrect xen_extra_mem_start initialization under 32-bit
git commit 24bdb0b62c (xen: do not create
the extra e820 region at an addr lower than 4G) does not take into
account that ifdef CONFIG_X86_32 instead of e820_end_of_low_ram_pfn()
find_low_pfn_range() is called (both calls are from arch/x86/kernel/setup.c).
find_low_pfn_range() behaves correctly and does not require change in
xen_extra_mem_start initialization. Additionally, if xen_extra_mem_start
is initialized in the same way as ifdef CONFIG_X86_64 then memory hotplug
support for Xen balloon driver (under development) is broken.

Signed-off-by: Daniel Kiper <dkiper@net-space.pl>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-12 14:37:06 -04:00
Konrad Rzeszutek Wilk 15bfc09451 xen/setup: Ignore E820_UNUSABLE when setting 1-1 mappings.
When we parse the raw E820, the Xen hypervisor can set "E820_RAM"
to "E820_UNUSABLE" if the mem=X argument is used. As such we
should _not_ consider the E820_UNUSABLE as an 1-1 identity
mapping, but instead use the same case as for E820_RAM.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-12 14:32:13 -04:00
Stefano Stabellini 24bdb0b62c xen: do not create the extra e820 region at an addr lower than 4G
Do not add the extra e820 region at a physical address lower than 4G
because it breaks e820_end_of_low_ram_pfn().

It is OK for us to move the xen_extra_mem_start up and down because this
is the index of the memory that can be ballooned in/out - it is memory
not available to the kernel during bootup.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-04-20 09:04:40 -04:00
Linus Torvalds c7146dd009 Merge branches 'stable/p2m-identity.v4.9.1' and 'stable/e820' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
* 'stable/p2m-identity.v4.9.1' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/m2p: Check whether the MFN has IDENTITY_FRAME bit set..
  xen/m2p: No need to catch exceptions when we know that there is no RAM
  xen/debug: WARN_ON when identity PFN has no _PAGE_IOMAP flag set.
  xen/debugfs: Add 'p2m' file for printing out the P2M layout.
  xen/setup: Set identity mapping for non-RAM E820 and E820 gaps.
  xen/mmu: WARN_ON when racing to swap middle leaf.
  xen/mmu: Set _PAGE_IOMAP if PFN is an identity PFN.
  xen/mmu: Add the notion of identity (1-1) mapping.
  xen: Mark all initial reserved pages for the balloon as INVALID_P2M_ENTRY.

* 'stable/e820' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/e820: Don't mark balloon memory as E820_UNUSABLE when running as guest and fix overflow.
  xen/setup: Inhibit resource API from using System RAM E820 gaps as PCI mem gaps.
2011-03-15 10:32:15 -07:00
Konrad Rzeszutek Wilk 68df0da7f4 xen/setup: Set identity mapping for non-RAM E820 and E820 gaps.
We walk the E820 region and start at 0 (for PV guests we start
at ISA_END_ADDRESS) and skip any E820 RAM regions. For all other
regions and as well the gaps we set them to be identity mappings.

The reasons we do not want to set the identity mapping from 0->
ISA_END_ADDRESS when running as PV is b/c that the kernel would
try to read DMI information and fail (no permissions to read that).
There is a lot of gnarly code to deal with that weird region so
we won't try to do a cleanup in this patch.

This code ends up calling 'set_phys_to_identity' with the start
and end PFN of the the E820 that are non-RAM or have gaps.
On 99% of machines that means one big region right underneath the
4GB mark. Usually starts at 0xc0000 (or 0x80000) and goes to
0x100000.

[v2: Fix for E820 crossing 1MB region and clamp the start]
[v3: Squshed in code that does this over ranges]
[v4: Moved the comment to the correct spot]
[v5: Use the "raw" E820 from the hypervisor]
[v6: Added Review-by tag]

Reviewed-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-14 11:17:10 -04:00
Konrad Rzeszutek Wilk 86b32122fd xen/e820: Don't mark balloon memory as E820_UNUSABLE when running as guest and fix overflow.
If we have a guest that asked for:

memory=1024
maxmem=2048

Which means we want 1GB now, and create pagetables so that we can expand
up to 2GB, we would have this E820 layout:

[    0.000000] BIOS-provided physical RAM map:
[    0.000000]  Xen: 0000000000000000 - 00000000000a0000 (usable)
[    0.000000]  Xen: 00000000000a0000 - 0000000000100000 (reserved)
[    0.000000]  Xen: 0000000000100000 - 0000000080800000 (usable)

Due to patch: "xen/setup: Inhibit resource API from using System RAM E820 gaps as PCI mem gaps."
we would mark the memory past the 1GB mark as unusuable resulting in:

[    0.000000] BIOS-provided physical RAM map:
[    0.000000]  Xen: 0000000000000000 - 00000000000a0000 (usable)
[    0.000000]  Xen: 00000000000a0000 - 0000000000100000 (reserved)
[    0.000000]  Xen: 0000000000100000 - 0000000040000000 (usable)
[    0.000000]  Xen: 0000000040000000 - 0000000080800000 (unusable)

which meant that we could not balloon up anymore. We could
balloon the guest down. The fix is to run the code introduced
by the above mentioned patch only for the initial domain.

We will have to revisit this once we start introducing a modified
E820 for PCI passthrough so that we can utilize the P2M identity code.

We also fix an overflow by having UL instead of ULL on 32-bit machines.

[v2: Ian pointed to the overflow issue]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-11 11:01:45 -05:00
Konrad Rzeszutek Wilk 6eaa412f27 xen: Mark all initial reserved pages for the balloon as INVALID_P2M_ENTRY.
With this patch, we diligently set regions that will be used by the
balloon driver to be INVALID_P2M_ENTRY and under the ownership
of the balloon driver. We are OK using the __set_phys_to_machine
as we do not expect to be allocating any P2M middle or entries pages.
The set_phys_to_machine has the side-effect of potentially allocating
new pages and we do not want that at this stage.

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

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

[v2: Rebased with mmu->p2m code split]
Reviewed-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-03 11:52:48 -05:00
Zhang, Fengzhe 2f14ddc3a7 xen/setup: Inhibit resource API from using System RAM E820 gaps as PCI mem gaps.
With the hypervisor argument of dom0_mem=X we iterate over the physical
(only for the initial domain) E820 and subtract the the size from each
E820_RAM region the delta so that the cumulative size of all E820_RAM regions
is equal to 'X'. This sometimes ends up with E820_RAM regions with zero size
(which are removed by e820_sanitize) and E820_RAM that are smaller
than physically.

Later on the PCI API looks at the E820 and attempts to set up an
resource region for the "PCI mem". The E820 (assume dom0_mem=1GB is
set) compared to the physical looks as so:

 [    0.000000] BIOS-provided physical RAM map:
 [    0.000000]  Xen: 0000000000000000 - 0000000000097c00 (usable)
 [    0.000000]  Xen: 0000000000097c00 - 0000000000100000 (reserved)
-[    0.000000]  Xen: 0000000000100000 - 00000000defafe00 (usable)
+[    0.000000]  Xen: 0000000000100000 - 0000000040000000 (usable)
 [    0.000000]  Xen: 00000000defafe00 - 00000000defb1ea0 (ACPI NVS)
 [    0.000000]  Xen: 00000000defb1ea0 - 00000000e0000000 (reserved)
 [    0.000000]  Xen: 00000000f4000000 - 00000000f8000000 (reserved)
..
And we get
[    0.000000] Allocating PCI resources starting at 40000000 (gap: 40000000:9efafe00)

while it should have started at e0000000 (a nice big gap up to
f4000000 exists). The "Allocating PCI" is part of the resource API.

The users that end up using those PCI I/O regions usually supply their
own BARs when calling the resource API (request_resource, or allocate_resource),
but there are exceptions which provide an empty 'struct resource' and
expect the API to provide the 'struct resource' to be populated with valid values.
The one that triggered this bug was the intel AGP driver that requested
a region for the flush page (intel_i9xx_setup_flush).

Before this patch, when running under Xen hypervisor, the 'struct resource'
returned could have (depending on the dom0_mem size) physical ranges of a 'System RAM'
instead of 'I/O' regions. This ended up with the Hypervisor failing a request
to populate PTE's with those PFNs as the domain did not have access to those
'System RAM' regions (rightly so).

After this patch, the left-over E820_RAM region from the truncation, will be
labeled as E820_UNUSABLE. The E820 will look as so:

 [    0.000000] BIOS-provided physical RAM map:
 [    0.000000]  Xen: 0000000000000000 - 0000000000097c00 (usable)
 [    0.000000]  Xen: 0000000000097c00 - 0000000000100000 (reserved)
-[    0.000000]  Xen: 0000000000100000 - 00000000defafe00 (usable)
+[    0.000000]  Xen: 0000000000100000 - 0000000040000000 (usable)
+[    0.000000]  Xen: 0000000040000000 - 00000000defafe00 (unusable)
 [    0.000000]  Xen: 00000000defafe00 - 00000000defb1ea0 (ACPI NVS)
 [    0.000000]  Xen: 00000000defb1ea0 - 00000000e0000000 (reserved)
 [    0.000000]  Xen: 00000000f4000000 - 00000000f8000000 (reserved)

For more information:
http://mid.gmane.org/1A42CE6F5F474C41B63392A5F80372B2335E978C@shsmsx501.ccr.corp.intel.com

BugLink: http://bugzilla.xensource.com/bugzilla/show_bug.cgi?id=1726

Signed-off-by: Fengzhe Zhang <fengzhe.zhang@intel.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-02-22 12:48:50 -05:00
Stefano Stabellini 23febeddbe xen/setup: Route halt operations to safe_halt pvop.
With this patch, the cpuidle driver does not load and
does not issue the mwait operations. Instead the hypervisor
is doing them (b/c we call the safe_halt pvops call).

This fixes quite a lot of bootup issues wherein the user had
to force interrupts for the continuation of the bootup.

Details are discussed in:

http://lists.xensource.com/archives/html/xen-devel/2011-01/msg00535.html

[v2: Wrote the commit description]

Reported-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Tested-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-01-27 12:00:24 -05:00
Stefano Stabellini 7cb31b752c xen/e820: Guard against E820_RAM not having page-aligned size or start.
Under Dell Inspiron 1525, and Intel SandyBridge SDP's the
BIOS e820 RAM is not page-aligned:

[   0.000000]  Xen: 0000000000100000 - 00000000df66d800 (usable)

We were not handling that and ended up setting up a pagetable
that included up to df66e000 with the disastrous effect that when

        memset(NODE_DATA(nodeid), 0, sizeof(pg_data_t));

tried to clear the page it would crash at the 2K mark.

Initially reported by Michael Young @
http://lists.xensource.com/archives/html/xen-devel/2011-01/msg00108.html

The fix is to page-align the size and also take into consideration
the start of the E820 (in case that is not page-aligned either). This
fixes the bootup failure on those affected machines.

This patch is a rework of the Micheal A Young initial patch and
considers the case if the start is not page-aligned.

Reported-by: Michael A Young <m.a.young@durham.ac.uk>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Michael A Young <m.a.young@durham.ac.uk>
2011-01-27 10:49:35 -05:00
Linus Torvalds 8338fded13 Merge branches 'upstream/core' and 'upstream/bugfix' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen
* 'upstream/core' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen:
  xen: allocate irq descs on any NUMA node
  xen: prevent crashes with non-HIGHMEM 32-bit kernels with largeish memory
  xen: use default_idle
  xen: clean up "extra" memory handling some more

* 'upstream/bugfix' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen:
  xen: x86/32: perform initial startup on initial_page_table
  xen: don't bother to stop other cpus on shutdown/reboot
2010-12-03 10:08:52 -08:00
Linus Torvalds 8a3fbc9fdb Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen: remove duplicated #include
  xen: x86/32: perform initial startup on initial_page_table
2010-11-25 08:35:53 +09:00
Huang Weiyi e6d4a76dbf xen: remove duplicated #include
Remove duplicated #include('s) in
  arch/x86/xen/setup.c

Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2010-11-24 12:07:45 -05:00