linux.git/drivers/xen, branch v3.6-rc2

Merge tag 'for-3.6' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

2012-07-24T23:17:07+00:00

Pull PCI changes from Bjorn Helgaas:
 "Host bridge hotplug:
    - Add MMCONFIG support for hot-added host bridges (Jiang Liu)
  Device hotplug:
    - Move fixups from __init to __devinit (Sebastian Andrzej Siewior)
    - Call FINAL fixups for hot-added devices, too (Myron Stowe)
    - Factor out generic code for P2P bridge hot-add (Yinghai Lu)
    - Remove all functions in a slot, not just those with _EJx (Amos
      Kong)
  Dynamic resource management:
    - Track bus number allocation (struct resource tree per domain)
      (Yinghai Lu)
    - Make P2P bridge 1K I/O windows work with resource reassignment
      (Bjorn Helgaas, Yinghai Lu)
    - Disable decoding while updating 64-bit BARs (Bjorn Helgaas)
  Power management:
    - Add PCIe runtime D3cold support (Huang Ying)
  Virtualization:
    - Add VFIO infrastructure (ACS, DMA source ID quirks) (Alex
      Williamson)
    - Add quirks for devices with broken INTx masking (Jan Kiszka)
  Miscellaneous:
    - Fix some PCI Express capability version issues (Myron Stowe)
    - Factor out some arch code with a weak, generic, pcibios_setup()
      (Myron Stowe)"

* tag 'for-3.6' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (122 commits)
  PCI: hotplug: ensure a consistent return value in error case
  PCI: fix undefined reference to 'pci_fixup_final_inited'
  PCI: build resource code for M68K architecture
  PCI: pciehp: remove unused pciehp_get_max_lnk_width(), pciehp_get_cur_lnk_width()
  PCI: reorder __pci_assign_resource() (no change)
  PCI: fix truncation of resource size to 32 bits
  PCI: acpiphp: merge acpiphp_debug and debug
  PCI: acpiphp: remove unused res_lock
  sparc/PCI: replace pci_cfg_fake_ranges() with pci_read_bridge_bases()
  PCI: call final fixups hot-added devices
  PCI: move final fixups from __init to __devinit
  x86/PCI: move final fixups from __init to __devinit
  MIPS/PCI: move final fixups from __init to __devinit
  PCI: support sizing P2P bridge I/O windows with 1K granularity
  PCI: reimplement P2P bridge 1K I/O windows (Intel P64H2)
  PCI: disable MEM decoding while updating 64-bit MEM BARs
  PCI: leave MEM and IO decoding disabled during 64-bit BAR sizing, too
  PCI: never discard enable/suspend/resume_early/resume fixups
  PCI: release temporary reference in __nv_msi_ht_cap_quirk()
  PCI: restructure 'pci_do_fixups()'
  ...

xen PVonHVM: move shared_info to MMIO before kexec

2012-07-19T19:52:05+00:00

Currently kexec in a PVonHVM guest fails with a triple fault because the
new kernel overwrites the shared info page. The exact failure depends on
the size of the kernel image. This patch moves the pfn from RAM into
MMIO space before the kexec boot.

The pfn containing the shared_info is located somewhere in RAM. This
will cause trouble if the current kernel is doing a kexec boot into a
new kernel. The new kernel (and its startup code) can not know where the
pfn is, so it can not reserve the page. The hypervisor will continue to
update the pfn, and as a result memory corruption occours in the new
kernel.

One way to work around this issue is to allocate a page in the
xen-platform pci device's BAR memory range. But pci init is done very
late and the shared_info page is already in use very early to read the
pvclock. So moving the pfn from RAM to MMIO is racy because some code
paths on other vcpus could access the pfn during the small   window when
the old pfn is moved to the new pfn. There is even a  small window were
the old pfn is not backed by a mfn, and during that time all reads
return -1.

Because it is not known upfront where the MMIO region is located it can
not be used right from the start in xen_hvm_init_shared_info.

To minimise trouble the move of the pfn is done shortly before kexec.
This does not eliminate the race because all vcpus are still online when
the syscore_ops will be called. But hopefully there is no work pending
at this point in time. Also the syscore_op is run last which reduces the
risk further.

Signed-off-by: Olaf Hering 
Signed-off-by: Konrad Rzeszutek Wilk

xen: enable platform-pci only in a Xen guest

2012-07-19T19:52:03+00:00

While debugging kexec issues in a PVonHVM guest I modified
xen_hvm_platform() to return false to disable all PV drivers. This
caused a crash in platform_pci_init() because it expects certain data
structures to be initialized properly.

To avoid such a crash make sure the driver is initialized only if
running in a Xen guest.

Signed-off-by: Olaf Hering 
Signed-off-by: Konrad Rzeszutek Wilk

xen/pv-on-hvm kexec: shutdown watches from old kernel

2012-07-19T19:52:02+00:00

Add xs_reset_watches function to shutdown watches from old kernel after
kexec boot.  The old kernel does not unregister all watches in the
shutdown path.  They are still active, the double registration can not
be detected by the new kernel.  When the watches fire, unexpected events
will arrive and the xenwatch thread will crash (jumps to NULL).  An
orderly reboot of a hvm guest will destroy the entire guest with all its
resources (including the watches) before it is rebuilt from scratch, so
the missing unregister is not an issue in that case.

With this change the xenstored is instructed to wipe all active watches
for the guest.  However, a patch for xenstored is required so that it
accepts the XS_RESET_WATCHES request from a client (see changeset
23839:42a45baf037d in xen-unstable.hg). Without the patch for xenstored
the registration of watches will fail and some features of a PVonHVM
guest are not available. The guest is still able to boot, but repeated
kexec boots will fail.

Signed-off-by: Olaf Hering 
Signed-off-by: Konrad Rzeszutek Wilk

xen/acpi: Fix potential memory leak.

2012-07-19T19:51:42+00:00

Coverity points out that we do not free in one case the
pr_backup - and sure enough we forgot.

Found by Coverity (CID 401970)

Signed-off-by: Konrad Rzeszutek Wilk

xen/mce: add .poll method for mcelog device driver

2012-07-19T19:51:41+00:00

If a driver leaves its poll method NULL, the device is assumed to
be both readable and writable without blocking.

This patch add .poll method to xen mcelog device driver, so that
when mcelog use system calls like ppoll or select, it would be
blocked when no data available, and avoid spinning at CPU.

Reported-by: Konrad Rzeszutek Wilk 
Signed-off-by: Liu, Jinsong 
Signed-off-by: Konrad Rzeszutek Wilk

xen/mce: schedule a workqueue to avoid sleep in atomic context

2012-07-19T19:51:40+00:00

copy_to_user might sleep and print a stack trace if it is executed
in an atomic spinlock context. Like this:

(XEN) CMCI: send CMCI to DOM0 through virq
BUG: sleeping function called from invalid context at /home/konradinux/kernel.h:199
in_atomic(): 1, irqs_disabled(): 0, pid: 4581, name: mcelog
Pid: 4581, comm: mcelog Tainted: G           O 3.5.0-rc1upstream-00003-g149000b-dirty #1
 [] __might_sleep+0xda/0x100
 [] xen_mce_chrdev_read+0xab/0x140
 [] vfs_read+0xc5/0x190
 [] sys_read+0x4c/0x90
 [] system_call_fastpath+0x16

This patch schedule a workqueue for IRQ handler to poll the data,
and use mutex instead of spinlock, so copy_to_user sleep in atomic
context would not occur.

Reported-by: Konrad Rzeszutek Wilk 
Suggested-by: Konrad Rzeszutek Wilk 
Signed-off-by: Liu, Jinsong 
Signed-off-by: Konrad Rzeszutek Wilk

xen/pcpu: Xen physical cpus online/offline sys interface

2012-07-19T19:51:39+00:00

This patch provide Xen physical cpus online/offline sys interface.
User can use it for their own purpose, like power saving:
by offlining some cpus when light workload it save power greatly.

Its basic workflow is, user online/offline cpu via sys interface,
then hypercall xen to implement, after done xen inject virq back to dom0,
and then dom0 sync cpu status.

Signed-off-by: Jiang, Yunhong 
Signed-off-by: Liu, Jinsong 
Signed-off-by: Konrad Rzeszutek Wilk

xen/mce: Add mcelog support for Xen platform

2012-07-19T19:51:36+00:00

When MCA error occurs, it would be handled by Xen hypervisor first,
and then the error information would be sent to initial domain for logging.

This patch gets error information from Xen hypervisor and convert
Xen format error into Linux format mcelog. This logic is basically
self-contained, not touching other kernel components.

By using tools like mcelog tool users could read specific error information,
like what they did under native Linux.

To test follow directions outlined in Documentation/acpi/apei/einj.txt

Acked-and-tested-by: Borislav Petkov 
Signed-off-by: Ke, Liping 
Signed-off-by: Jiang, Yunhong 
Signed-off-by: Jeremy Fitzhardinge 
Signed-off-by: Liu, Jinsong 
Signed-off-by: Konrad Rzeszutek Wilk

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

2012-06-16T00:17:15+00:00

Pull five Xen bug-fixes from Konrad Rzeszutek Wilk:

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

* tag 'stable/for-linus-3.5-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen: mark local pages as FOREIGN in the m2p_override
  xen/setup: filter APERFMPERF cpuid feature out
  xen/balloon: Subtract from xen_released_pages the count that is populated.
  xen/pci: Check for PCI bridge before using it.
  xen/events: Add WARN_ON when quick lookup found invalid type.
  xen/hvc: Check HVM_PARAM_CONSOLE_[EVTCHN|PFN] for correctness.
  xen/hvc: Fix error cases around HVM_PARAM_CONSOLE_PFN
  xen/hvc: Collapse error logic.