Commit Graph

698 Commits

Author SHA1 Message Date
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
Zhenzhong Duan 90d4f5534d xen:pvhvm: enable PVHVM VCPU placement when using more than 32 CPUs.
PVHVM running with more than 32 vcpus and pv_irq/pv_time enabled
need VCPU placement to work, or else it will softlockup.

CC: stable@kernel.org
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-11-16 12:13:44 -05:00
David Vrabel cd12909cb5 xen: map foreign pages for shared rings by updating the PTEs directly
When mapping a foreign page with xenbus_map_ring_valloc() with the
GNTTABOP_map_grant_ref hypercall, set the GNTMAP_contains_pte flag and
pass a pointer to the PTE (in init_mm).

After the page is mapped, the usual fault mechanism can be used to
update additional MMs.  This allows the vmalloc_sync_all() to be
removed from alloc_vm_area().

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
[v1: Squashed fix by Michal for no-mmu case]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>
2011-11-16 12:13:08 -05:00
Linus Torvalds 403299a851 Merge branch 'upstream/xen-settime' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen
* 'upstream/xen-settime' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen:
  xen/dom0: set wallclock time in Xen
  xen: add dom0_op hypercall
  xen/acpi: Domain0 acpi parser related platform hypercall
2011-11-06 20:15:05 -08:00
Linus Torvalds 06d381484f Merge branch 'stable/vmalloc-3.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
* 'stable/vmalloc-3.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  net: xen-netback: use API provided by xenbus module to map rings
  block: xen-blkback: use API provided by xenbus module to map rings
  xen: use generic functions instead of xen_{alloc, free}_vm_area()
2011-11-06 18:31:36 -08:00
Linus Torvalds 04a8752485 Merge branches 'stable/drivers-3.2', 'stable/drivers.bugfixes-3.2' and 'stable/pci.fixes-3.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
* 'stable/drivers-3.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xenbus: don't rely on xen_initial_domain to detect local xenstore
  xenbus: Fix loopback event channel assuming domain 0
  xen/pv-on-hvm:kexec: Fix implicit declaration of function 'xen_hvm_domain'
  xen/pv-on-hvm kexec: add xs_reset_watches to shutdown watches from old kernel
  xen/pv-on-hvm kexec: update xs_wire.h:xsd_sockmsg_type from xen-unstable
  xen/pv-on-hvm kexec+kdump: reset PV devices in kexec or crash kernel
  xen/pv-on-hvm kexec: rebind virqs to existing eventchannel ports
  xen/pv-on-hvm kexec: prevent crash in xenwatch_thread() when stale watch events arrive

* 'stable/drivers.bugfixes-3.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/pciback: Check if the device is found instead of blindly assuming so.
  xen/pciback: Do not dereference psdev during printk when it is NULL.
  xen: remove XEN_PLATFORM_PCI config option
  xen: XEN_PVHVM depends on PCI
  xen/pciback: double lock typo
  xen/pciback: use mutex rather than spinlock in vpci backend
  xen/pciback: Use mutexes when working with Xenbus state transitions.
  xen/pciback: miscellaneous adjustments
  xen/pciback: use mutex rather than spinlock in passthrough backend
  xen/pciback: use resource_size()

* 'stable/pci.fixes-3.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/pci: support multi-segment systems
  xen-swiotlb: When doing coherent alloc/dealloc check before swizzling the MFNs.
  xen/pci: make bus notifier handler return sane values
  xen-swiotlb: fix printk and panic args
  xen-swiotlb: Fix wrong panic.
  xen-swiotlb: Retry up three times to allocate Xen-SWIOTLB
  xen-pcifront: Update warning comment to use 'e820_host' option.
2011-10-25 09:19:36 +02:00
Linus Torvalds 31018acd4c Merge branches 'stable/bug.fixes-3.2' and 'stable/mmu.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
* 'stable/bug.fixes-3.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/p2m/debugfs: Make type_name more obvious.
  xen/p2m/debugfs: Fix potential pointer exception.
  xen/enlighten: Fix compile warnings and set cx to known value.
  xen/xenbus: Remove the unnecessary check.
  xen/irq: If we fail during msi_capability_init return proper error code.
  xen/events: Don't check the info for NULL as it is already done.
  xen/events: BUG() when we can't allocate our event->irq array.

* 'stable/mmu.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen: Fix selfballooning and ensure it doesn't go too far
  xen/gntdev: Fix sleep-inside-spinlock
  xen: modify kernel mappings corresponding to granted pages
  xen: add an "highmem" parameter to alloc_xenballooned_pages
  xen/p2m: Use SetPagePrivate and its friends for M2P overrides.
  xen/p2m: Make debug/xen/mmu/p2m visible again.
  Revert "xen/debug: WARN_ON when identity PFN has no _PAGE_IOMAP flag set."
2011-10-25 09:17:47 +02:00
Konrad Rzeszutek Wilk a491dbef56 xen/p2m/debugfs: Make type_name more obvious.
Per Ian Campbell suggestion to defend against future breakage
in case we expand the P2M values, incorporate the defines
in the string array.

Suggested-by: Ian Campbell <Ian.Campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-10-19 17:03:34 -04:00
Konrad Rzeszutek Wilk 8404877ee1 xen/p2m/debugfs: Fix potential pointer exception.
We could be referencing the last + 1 element of level_name[]
array which would cause a pointer exception, because of the
initial setup of lvl=4.

[v1: No need to do this for type_name, pointed out by Ian Campbell]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-10-19 17:03:32 -04:00
Konrad Rzeszutek Wilk 5e28783013 xen/enlighten: Fix compile warnings and set cx to known value.
We get:
linux/arch/x86/xen/enlighten.c: In function ‘xen_start_kernel’:
linux/arch/x86/xen/enlighten.c:226: warning: ‘cx’ may be used uninitialized in this function
linux/arch/x86/xen/enlighten.c:240: note: ‘cx’ was declared here

and the cx is really not set but passed in the xen_cpuid instruction
which masks the value with returned masked_ecx from cpuid. This
can potentially lead to invalid data being stored in cx.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-10-19 17:03:31 -04:00
David Vrabel 4dcaebbf65 xen: use generic functions instead of xen_{alloc, free}_vm_area()
Replace calls to the Xen-specific xen_alloc_vm_area() and
xen_free_vm_area() functions with the generic equivalent
(alloc_vm_area() and free_vm_area()).

On x86, these were identical already.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-09-29 15:02:18 -04:00
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
Stefano Stabellini b17d0b5c08 xen: XEN_PVHVM depends on PCI
Xen PV on HVM guests require PCI support because they need the
xen-platform-pci driver in order to initialize xenbus.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-09-29 10:52:16 -04:00
Stefano Stabellini 0930bba674 xen: modify kernel mappings corresponding to granted pages
If we want to use granted pages for AIO, changing the mappings of a user
vma and the corresponding p2m is not enough, we also need to update the
kernel mappings accordingly.
Currently this is only needed for pages that are created for user usages
through /dev/xen/gntdev. As in, pages that have been in use by the
kernel and use the P2M will not need this special mapping.
However there are no guarantees that in the future the kernel won't
start accessing pages through the 1:1 even for internal usage.

In order to avoid the complexity of dealing with highmem, we allocated
the pages lowmem.
We issue a HYPERVISOR_grant_table_op right away in
m2p_add_override and we remove the mappings using another
HYPERVISOR_grant_table_op in m2p_remove_override.
Considering that m2p_add_override and m2p_remove_override are called
once per page we use multicalls and hypercall batching.

Use the kmap_op pointer directly as argument to do the mapping as it is
guaranteed to be present up until the unmapping is done.
Before issuing any unmapping multicalls, we need to make sure that the
mapping has already being done, because we need the kmap->handle to be
set correctly.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
[v1: Removed GRANT_FRAME_BIT usage]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-09-29 10:32:58 -04:00
Jeremy Fitzhardinge fdb9eb9f15 xen/dom0: set wallclock time in Xen
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2011-09-26 11:04:39 -07:00
Konrad Rzeszutek Wilk 0f4b49eaf2 xen/p2m: Use SetPagePrivate and its friends for M2P overrides.
We use the page->private field and hence should use the proper
macros and set proper bits. Also WARN_ON in case somebody
tries to overwrite our data.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-09-23 22:22:33 -04:00
Konrad Rzeszutek Wilk a867db10e8 xen/p2m: Make debug/xen/mmu/p2m visible again.
We dropped a lot of the MMU debugfs in favour of using
tracing API - but there is one which just provides
mostly static information that was made invisible by this change.

Bring it back.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-09-23 22:22:32 -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
Jan Beulich 61cca2fab7 xen/i386: follow-up to "replace order-based range checking of M2P table by linear one"
The numbers obtained from the hypervisor really can't ever lead to an
overflow here, only the original calculation going through the order
of the range could have. This avoids the (as Jeremy points outs)
somewhat ugly NULL-based calculation here.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-09-15 04:39:46 -04:00
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 d9543314ee Merge branch 'upstream/bugfix' of git://github.com/jsgf/linux-xen
* 'upstream/bugfix' of git://github.com/jsgf/linux-xen:
  xen: use non-tracing preempt in xen_clocksource_read()
2011-09-12 17:22:31 -07:00
Stefano Stabellini f10cd522c5 xen: disable PV spinlocks on HVM
PV spinlocks cannot possibly work with the current code because they are
enabled after pvops patching has already been done, and because PV
spinlocks use a different data structure than native spinlocks so we
cannot switch between them dynamically. A spinlock that has been taken
once by the native code (__ticket_spin_lock) cannot be taken by
__xen_spin_lock even after it has been released.

Reported-and-Tested-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-09-08 13:59:06 -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
Konrad Rzeszutek Wilk ed467e69f1 xen/smp: Warn user why they keel over - nosmp or noapic and what to use instead.
We have hit a couple of customer bugs where they would like to
use those parameters to run an UP kernel - but both of those
options turn of important sources of interrupt information so
we end up not being able to boot. The correct way is to
pass in 'dom0_max_vcpus=1' on the Xen hypervisor line and
the kernel will patch itself to be a UP kernel.

Fixes bug: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=637308

CC: stable@kernel.org
Acked-by: Ian Campbell <Ian.Campbell@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-09-01 12:54:49 -04:00
Igor Mammedov d198d49914 xen: x86_32: do not enable iterrupts when returning from exception in interrupt context
If vmalloc page_fault happens inside of interrupt handler with interrupts
disabled then on exit path from exception handler when there is no pending
interrupts, the following code (arch/x86/xen/xen-asm_32.S:112):

	cmpw $0x0001, XEN_vcpu_info_pending(%eax)
	sete XEN_vcpu_info_mask(%eax)

will enable interrupts even if they has been previously disabled according to
eflags from the bounce frame (arch/x86/xen/xen-asm_32.S:99)

	testb $X86_EFLAGS_IF>>8, 8+1+ESP_OFFSET(%esp)
	setz XEN_vcpu_info_mask(%eax)

Solution is in setting XEN_vcpu_info_mask only when it should be set
according to
	cmpw $0x0001, XEN_vcpu_info_pending(%eax)
but not clearing it if there isn't any pending events.

Reproducer for bug is attached to RHBZ 707552

CC: stable@kernel.org
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-09-01 12:54:42 -04:00
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
Jeremy Fitzhardinge f1c39625d6 xen: use non-tracing preempt in xen_clocksource_read()
The tracing code used sched_clock() to get tracing timestamps, which
ends up calling xen_clocksource_read().  xen_clocksource_read() must
disable preemption, but if preemption tracing is enabled, this results
in infinite recursion.

I've only noticed this when boot-time tracing tests are enabled, but it
seems like a generic bug.  It looks like it would also affect
kvm_clocksource_read().

Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
2011-08-24 09:54:24 -07:00
Linus Torvalds 4762e252f4 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/tracing: Fix tracing config option properly
  xen: Do not enable PV IPIs when vector callback not present
  xen/x86: replace order-based range checking of M2P table by linear one
  xen: xen-selfballoon.c needs more header files
2011-08-22 11:25:44 -07:00
Jeremy Fitzhardinge 60c5f08e15 xen/tracing: Fix tracing config option properly
Steven Rostedt says we should use CONFIG_EVENT_TRACING.

Cc:Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-08-22 11:28:33 -04:00
Stefano Stabellini 3c05c4bed4 xen: Do not enable PV IPIs when vector callback not present
Fix regression for HVM case on older (<4.1.1) hypervisors caused by

  commit 99bbb3a84a
  Author: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
  Date:   Thu Dec 2 17:55:10 2010 +0000

    xen: PV on HVM: support PV spinlocks and IPIs

This change replaced the SMP operations with event based handlers without
taking into account that this only works when the hypervisor supports
callback vectors. This causes unexplainable hangs early on boot for
HVM guests with more than one CPU.

BugLink: http://bugs.launchpad.net/bugs/791850

CC: stable@kernel.org
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Tested-and-Reported-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-08-22 11:28:09 -04:00
Jan Beulich ccbcdf7cf1 xen/x86: replace order-based range checking of M2P table by linear one
The order-based approach is not only less efficient (requiring a shift
and a compare, typical generated code looking like this

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

whereas a direct check requires just a compare, like in

	cmp	ebx, [machine_to_phys_nr]
	jae	...

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

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

CC: stable@kernel.org
Signed-off-by: Jan Beulich <jbeulich@novell.com>
[v1: Based on Jeremy's feedback]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-08-17 10:26:48 -04:00
Linus Torvalds 06e727d2a5 Merge branch 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-tip
* 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-tip:
  x86-64: Rework vsyscall emulation and add vsyscall= parameter
  x86-64: Wire up getcpu syscall
  x86: Remove unnecessary compile flag tweaks for vsyscall code
  x86-64: Add vsyscall:emulate_vsyscall trace event
  x86-64: Add user_64bit_mode paravirt op
  x86-64, xen: Enable the vvar mapping
  x86-64: Work around gold bug 13023
  x86-64: Move the "user" vsyscall segment out of the data segment.
  x86-64: Pad vDSO to a page boundary
2011-08-12 20:46:24 -07:00
Konrad Rzeszutek Wilk 10fe570fc1 Revert "xen/debug: WARN_ON when identity PFN has no _PAGE_IOMAP flag set."
We don' use it anymore and there are more false positives.

This reverts commit fc25151d9a.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-08-09 13:04:08 -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
Konrad Rzeszutek Wilk c00c8aa2d9 xen/trace: Fix compile error when CONFIG_XEN_PRIVILEGED_GUEST is not set
with CONFIG_XEN and CONFIG_FTRACE set we get this:

arch/x86/xen/trace.c:22: error: ‘__HYPERVISOR_console_io’ undeclared here (not in a function)
arch/x86/xen/trace.c:22: error: array index in initializer not of integer type
arch/x86/xen/trace.c:22: error: (near initialization for ‘xen_hypercall_names’)
arch/x86/xen/trace.c:23: error: ‘__HYPERVISOR_physdev_op_compat’ undeclared here (not in a function)

Issue was that the definitions of __HYPERVISOR were not pulled
if CONFIG_XEN_PRIVILEGED_GUEST was not set.

Reported-by: Randy Dunlap <rdunlap@xenotime.net>
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-08-05 09:43:02 -04:00
Andy Lutomirski 318f5a2a67 x86-64: Add user_64bit_mode paravirt op
Three places in the kernel assume that the only long mode CPL 3
selector is __USER_CS.  This is not true on Xen -- Xen's sysretq
changes cs to the magic value 0xe033.

Two of the places are corner cases, but as of "x86-64: Improve
vsyscall emulation CS and RIP handling"
(c9712944b2), vsyscalls will segfault
if called with Xen's extra CS selector.  This causes a panic when
older init builds die.

It seems impossible to make Xen use __USER_CS reliably without
taking a performance hit on every system call, so this fixes the
tests instead with a new paravirt op.  It's a little ugly because
ptrace.h can't include paravirt.h.

Signed-off-by: Andy Lutomirski <luto@mit.edu>
Link: http://lkml.kernel.org/r/f4fcb3947340d9e96ce1054a432f183f9da9db83.1312378163.git.luto@mit.edu
Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-08-04 16:13:49 -07:00
Andy Lutomirski 5d5791af4c x86-64, xen: Enable the vvar mapping
Xen needs to handle VVAR_PAGE, introduced in git commit:
9fd67b4ed0
x86-64: Give vvars their own page

Otherwise we die during bootup with a message like:

(XEN) mm.c:940:d10 Error getting mfn 1888 (pfn 1e3e48) from L1 entry
      8000000001888465 for l1e_owner=10, pg_owner=10
(XEN) mm.c:5049:d10 ptwr_emulate: could not get_page_from_l1e()
[    0.000000] BUG: unable to handle kernel NULL pointer dereference at (null)
[    0.000000] IP: [<ffffffff8103a930>] xen_set_pte+0x20/0xe0

Signed-off-by: Andy Lutomirski <luto@mit.edu>
Link: http://lkml.kernel.org/r/4659478ed2f3480938f96491c2ecbe2b2e113a23.1312378163.git.luto@mit.edu
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-08-04 16:13:47 -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
Jeremy Fitzhardinge 1e9ea2656b xen/tracing: it looks like we wanted CONFIG_FTRACE
Apparently we wanted CONFIG_FTRACE rather the CONFIG_FUNCTION_TRACER.

Reported-by: Sander Eikelenboom <linux@eikelenboom.it>
Tested-by: Sander Eikelenboom <linux@eikelenboom.it>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-08-04 15:31:27 -04:00
Linus Torvalds 35e51fe82d Merge branch 'idle-release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-idle-2.6
* 'idle-release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-idle-2.6:
  cpuidle: stop depending on pm_idle
  x86 idle: move mwait_idle_with_hints() to where it is used
  cpuidle: replace xen access to x86 pm_idle and default_idle
  cpuidle: create bootparam "cpuidle.off=1"
  mrst_pmu: driver for Intel Moorestown Power Management Unit
2011-08-03 21:54:15 -10:00
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
Linus Torvalds b993fdbc7f Merge branch 'upstream/xen-tracing2' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen
* 'upstream/xen-tracing2' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen:
  xen/tracing: fix compile errors when tracing is disabled.
2011-07-29 23:33:40 -07:00
Jeremy Fitzhardinge b3c4b98250 xen/tracing: fix compile errors when tracing is disabled.
When CONFIG_FUNCTION_TRACER is disabled, compilation fails as follows:
  CC      arch/x86/xen/setup.o
In file included from arch/x86/include/asm/xen/hypercall.h:42,
                 from arch/x86/xen/setup.c:19:
include/trace/events/xen.h:31: warning: 'struct multicall_entry' declared inside parameter list
include/trace/events/xen.h:31: warning: its scope is only this definition or declaration, which is probably not what you want
include/trace/events/xen.h:31: warning: 'struct multicall_entry' declared inside parameter list
include/trace/events/xen.h:31: warning: 'struct multicall_entry' declared inside parameter list
include/trace/events/xen.h:31: warning: 'struct multicall_entry' declared inside parameter list
[...]
arch/x86/xen/trace.c:5: error: '__HYPERVISOR_set_trap_table' undeclared here (not in a function)
arch/x86/xen/trace.c:5: error: array index in initializer not of integer type
arch/x86/xen/trace.c:5: error: (near initialization for 'xen_hypercall_names')
arch/x86/xen/trace.c:6: error: '__HYPERVISOR_mmu_update' undeclared here (not in a function)
arch/x86/xen/trace.c:6: error: array index in initializer not of integer type
arch/x86/xen/trace.c:6: error: (near initialization for 'xen_hypercall_names')

Fix this by making sure struct multicall_entry has a declaration in
scope at all times, and don't bother compiling xen/trace.c when tracing
is disabled.

Reported-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2011-07-25 15:51:02 -07:00
Linus Torvalds c61264f98c Merge branch 'upstream/xen-tracing2' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen
* 'upstream/xen-tracing2' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen:
  xen/trace: use class for multicall trace
  xen/trace: convert mmu events to use DECLARE_EVENT_CLASS()/DEFINE_EVENT()
  xen/multicall: move *idx fields to start of mc_buffer
  xen/multicall: special-case singleton hypercalls
  xen/multicalls: add unlikely around slowpath in __xen_mc_entry()
  xen/multicalls: disable MC_DEBUG
  xen/mmu: tune pgtable alloc/release
  xen/mmu: use extend_args for more mmuext updates
  xen/trace: add tlb flush tracepoints
  xen/trace: add segment desc tracing
  xen/trace: add xen_pgd_(un)pin tracepoints
  xen/trace: add ptpage alloc/release tracepoints
  xen/trace: add mmu tracepoints
  xen/trace: add multicall tracing
  xen/trace: set up tracepoint skeleton
  xen/multicalls: remove debugfs stats
  trace/xen: add skeleton for Xen trace events
2011-07-24 09:06:47 -07:00