Commit Graph

1005 Commits

Author SHA1 Message Date
Linus Torvalds 1cd731df09 Bug-fixes:
- Revert "xen/grant-table: Avoid m2p_override during mapping" as it broke Xen ARM build.
  - Fix CR4 not being set on AP processors in Xen PVH mode.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQEcBAABAgAGBQJS8AyQAAoJEFjIrFwIi8fJbD4IAJssMuaLI5CRsSWBgDFHHDFt
 srVJpDOYQiDr/TxkwFCVcL4sFy9Htb3KMArU4eIBl6uMqQbGa+3rHyXcHYI219YY
 XH3D8RG+9JChwsxtaeUEzwx1C8ehcygD34vtdcoQXa7eBuEi4TL3HeLifR+HrXKO
 UdFrTA34FmvpVFbSuRXkZh5sd6ca9et9xHuQHM8SIY6pVokY6xaEYOp17tfPZpwM
 7A6LFjUjXeugHC2L3+/H8UOHA9nSZQvnMiZOWq2Cusc2Dt2V7emzgk2wcc2CHttf
 EA6GbtiJzHqMPmt5EjubI9hHdSMB31HpY4hnQE38+ucl+BwiSdRE9z2Rm4TYClg=
 =IX4M
 -----END PGP SIGNATURE-----

Merge tag 'stable/for-linus-3.14-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull Xen fixes from Konrad Rzeszutek Wilk:
 "Bug-fixes:
   - Revert "xen/grant-table: Avoid m2p_override during mapping" as it
     broke Xen ARM build.
   - Fix CR4 not being set on AP processors in Xen PVH mode"

* tag 'stable/for-linus-3.14-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/pvh: set CR4 flags for APs
  Revert "xen/grant-table: Avoid m2p_override during mapping"
2014-02-05 16:01:11 -08:00
Mukesh Rathor afca50132c xen/pvh: set CR4 flags for APs
During bootup in the 'probe_page_size_mask' these CR4 flags are
set in there. But for AP processors they are not set as we do not
use 'secondary_startup_64' which the baremetal kernels uses.
Instead do it in this function which we use in Xen PVH during our
startup for AP processors.

As such fix it up to make sure we have that flag set.

Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2014-02-03 15:44:18 -05:00
Konrad Rzeszutek Wilk e85fc98055 Revert "xen/grant-table: Avoid m2p_override during mapping"
This reverts commit 08ece5bb23.

As it breaks ARM builds and needs more attention
on the ARM side.

Acked-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2014-02-03 06:44:49 -05:00
Linus Torvalds 14164b46fc Bug-fixes:
- Xen ARM couldn't use the new FIFO events
  - Xen ARM couldn't use the SWIOTLB if compiled as 32-bit with 64-bit PCIe devices.
  - Grant table were doing needless M2P operations.
  - Ratchet down the self-balloon code so it won't OOM.
  - Fix misplaced kfree in Xen PVH error code paths.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQEcBAABAgAGBQJS68IQAAoJEFjIrFwIi8fJAWgH/j4HStEey3rgGcqwIWSHkkap
 +t55wsrT8Ylq6CzZjaUtCo3pB7HotW526x/0rA2pxVqHn/8oCN/1EtdrNtYm/umX
 qOoda+db5NIjAEGVLWSLqGyokJQDrX/brXIWfYR300e9fnJi7yT/rFC4QHoZVUYl
 5LME8XH/jE012vvYelNu6DbbodlRmVCT8hctJS+eB5ER2WmtD9Pkw4GybEXPVYJz
 hE0Ts1DN91nKP2FGJb+mfB9UFT5X8i00akAK+Qc1R3sRnRh6eRoNV8dgyCnudKpO
 UPEdiAZvgij+mzlgIYSz6nKH0U/VbvRsG3lc3i5Si3o+vR3CYPCkvzOGX2d0rjw=
 =7cxW
 -----END PGP SIGNATURE-----

Merge tag 'stable/for-linus-3.14-rc0-late-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull Xen bugfixes from Konrad Rzeszutek Wilk:
 "Bug-fixes for the new features that were added during this cycle.

  There are also two fixes for long-standing issues for which we have a
  solution: grant-table operations extra work that was not needed
  causing performance issues and the self balloon code was too
  aggressive causing OOMs.

  Details:
   - Xen ARM couldn't use the new FIFO events
   - Xen ARM couldn't use the SWIOTLB if compiled as 32-bit with 64-bit PCIe devices.
   - Grant table were doing needless M2P operations.
   - Ratchet down the self-balloon code so it won't OOM.
   - Fix misplaced kfree in Xen PVH error code paths"

* tag 'stable/for-linus-3.14-rc0-late-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/pvh: Fix misplaced kfree from xlated_setup_gnttab_pages
  drivers: xen: deaggressive selfballoon driver
  xen/grant-table: Avoid m2p_override during mapping
  xen/gnttab: Use phys_addr_t to describe the grant frame base address
  xen: swiotlb: handle sizeof(dma_addr_t) != sizeof(phys_addr_t)
  arm/xen: Initialize event channels earlier
2014-01-31 08:38:18 -08:00
Dave Jones f93576e1ac xen/pvh: Fix misplaced kfree from xlated_setup_gnttab_pages
Passing a freed 'pages' to free_xenballooned_pages will end badly
on kernels with slub debug enabled.

This looks out of place between the rc assign and the check, but
we do want to kfree pages regardless of which path we take.

Signed-off-by: Dave Jones <davej@fedoraproject.org>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2014-01-31 09:48:58 -05:00
Zoltan Kiss 08ece5bb23 xen/grant-table: Avoid m2p_override during mapping
The grant mapping API does m2p_override unnecessarily: only gntdev needs it,
for blkback and future netback patches it just cause a lock contention, as
those pages never go to userspace. Therefore this series does the following:
- the original functions were renamed to __gnttab_[un]map_refs, with a new
  parameter m2p_override
- based on m2p_override either they follow the original behaviour, or just set
  the private flag and call set_phys_to_machine
- gnttab_[un]map_refs are now a wrapper to call __gnttab_[un]map_refs with
  m2p_override false
- a new function gnttab_[un]map_refs_userspace provides the old behaviour

It also removes a stray space from page.h and change ret to 0 if
XENFEAT_auto_translated_physmap, as that is the only possible return value
there.

v2:
- move the storing of the old mfn in page->index to gnttab_map_refs
- move the function header update to a separate patch

v3:
- a new approach to retain old behaviour where it needed
- squash the patches into one

v4:
- move out the common bits from m2p* functions, and pass pfn/mfn as parameter
- clear page->private before doing anything with the page, so m2p_find_override
  won't race with this

v5:
- change return value handling in __gnttab_[un]map_refs
- remove a stray space in page.h
- add detail why ret = 0 now at some places

v6:
- don't pass pfn to m2p* functions, just get it locally

Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com>
Suggested-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2014-01-31 09:48:32 -05:00
Linus Torvalds 12f2bbd609 Merge branch 'x86-asmlinkage-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 asmlinkage (LTO) changes from Peter Anvin:
 "This patchset adds more infrastructure for link time optimization
  (LTO).

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

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

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

Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1382458079-24450-8-git-send-email-andi@firstfloor.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-01-29 22:17:18 -08:00
Andi Kleen dd41f818e5 x86, asmlinkage, xen, kvm: Make {xen,kvm}_lock_spinning global and visible
These functions are called from inline assembler stubs, thus
need to be global and visible.

Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1382458079-24450-7-git-send-email-andi@firstfloor.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-01-29 22:17:18 -08:00
Andi Kleen a2e7f0e3a4 x86, asmlinkage, paravirt: Make paravirt thunks global
The paravirt thunks use a hack of using a static reference to a static
function to reference that function from the top level statement.

This assumes that gcc always generates static function names in a specific
format, which is not necessarily true.

Simply make these functions global and asmlinkage or __visible. This way the
static __used variables are not needed and everything works.

Functions with arguments are __visible to keep the register calling
convention on 32bit.

Changed in paravirt and in all users (Xen and vsmp)

v2: Use __visible for functions with arguments

Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Ido Yariv <ido@wizery.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1382458079-24450-5-git-send-email-andi@firstfloor.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-01-29 22:17:17 -08:00
Roger Pau Monne c9f6e9977e xen/pvh: Set X86_CR0_WP and others in CR0 (v2)
otherwise we will get for some user-space applications
that use 'clone' with CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID
end up hitting an assert in glibc manifested by:

general protection ip:7f80720d364c sp:7fff98fd8a80 error:0 in
libc-2.13.so[7f807209e000+180000]

This is due to the nature of said operations which sets and clears
the PID.  "In the successful one I can see that the page table of
the parent process has been updated successfully to use a
different physical page, so the write of the tid on
that page only affects the child...

On the other hand, in the failed case, the write seems to happen before
the copy of the original page is done, so both the parent and the child
end up with the same value (because the parent copies the page after
the write of the child tid has already happened)."
(Roger's analysis). The nature of this is due to the Xen's commit
of 51e2cac257ec8b4080d89f0855c498cbbd76a5e5
"x86/pvh: set only minimal cr0 and cr4 flags in order to use paging"
the CR0_WP was removed so COW features of the Linux kernel were not
operating properly.

While doing that also update the rest of the CR0 flags to be inline
with what a baremetal Linux kernel would set them to.

In 'secondary_startup_64' (baremetal Linux) sets:

X86_CR0_PE | X86_CR0_MP | X86_CR0_ET | X86_CR0_NE | X86_CR0_WP |
X86_CR0_AM | X86_CR0_PG

The hypervisor for HVM type guests (which PVH is a bit) sets:
X86_CR0_PE | X86_CR0_ET | X86_CR0_TS
For PVH it specifically sets:
X86_CR0_PG

Which means we need to set the rest: X86_CR0_MP | X86_CR0_NE  |
X86_CR0_WP | X86_CR0_AM to have full parity.

Signed-off-by: Roger Pau Monne <roger.pau@citrix.com>
Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[v1: Took out the cr4 writes to be a seperate patch]
[v2: 0-DAY kernel found xen_setup_gdt to be missing a static]
2014-01-21 13:26:05 -05:00
Konrad Rzeszutek Wilk 54d44eb3c7 xen/pvh: Use 'depend' instead of 'select'.
The usage of 'select' means it will enable the CONFIG
options without checking their dependencies. That meant
we would inadvertently turn on CONFIG_XEN_PVHM while its
core dependency (CONFIG_PCI) was turned off.

This patch fixes the warnings and compile failures:

warning: (XEN_PVH) selects XEN_PVHVM which has unmet direct
dependencies (HYPERVISOR_GUEST && XEN && PCI && X86_LOCAL_APIC)

Reported-by: Jim Davis <jim.epost@gmail.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2014-01-10 10:45:35 -05:00
Wei Yongjun 5602aba808 xen/pvh: remove duplicated include from enlighten.c
Remove duplicated include.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2014-01-07 09:59:49 -05:00
Konrad Rzeszutek Wilk 0869a64232 xen/pvh: Fix compile issues with xen_pvh_domain()
Oddly enough it compiles for my ancient compiler but with
the supplied .config it does blow up. Fix is easy enough.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Reported-by: Jim Davis <jim.epost@gmail.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2014-01-07 09:59:28 -05:00
Mukesh Rathor 4e903a20da xen/pvh: Support ParaVirtualized Hardware extensions (v3).
PVH allows PV linux guest to utilize hardware extended capabilities,
such as running MMU updates in a HVM container.

The Xen side defines PVH as (from docs/misc/pvh-readme.txt,
with modifications):

"* the guest uses auto translate:
 - p2m is managed by Xen
 - pagetables are owned by the guest
 - mmu_update hypercall not available
* it uses event callback and not vlapic emulation,
* IDT is native, so set_trap_table hcall is also N/A for a PVH guest.

For a full list of hcalls supported for PVH, see pvh_hypercall64_table
in arch/x86/hvm/hvm.c in xen.  From the ABI prespective, it's mostly a
PV guest with auto translate, although it does use hvm_op for setting
callback vector."

Use .ascii and .asciz to define xen feature string. Note, the PVH
string must be in a single line (not multiple lines with \) to keep the
assembler from putting null char after each string before \.
This patch allows it to be configured and enabled.

We also use introduce the 'XEN_ELFNOTE_SUPPORTED_FEATURES' ELF note to
tell the hypervisor that 'hvm_callback_vector' is what the kernel
needs. We can not put it in 'XEN_ELFNOTE_FEATURES' as older hypervisor
parse fields they don't understand as errors and refuse to load
the kernel. This work-around fixes the problem.

Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2014-01-06 10:44:24 -05:00
Konrad Rzeszutek Wilk 6926f6d610 xen/pvh: Piggyback on PVHVM for grant driver (v4)
In PVH the shared grant frame is the PFN and not MFN,
hence its mapped via the same code path as HVM.

The allocation of the grant frame is done differently - we
do not use the early platform-pci driver and have an
ioremap area - instead we use balloon memory and stitch
all of the non-contingous pages in a virtualized area.

That means when we call the hypervisor to replace the GMFN
with a XENMAPSPACE_grant_table type, we need to lookup the
old PFN for every iteration instead of assuming a flat
contingous PFN allocation.

Lastly, we only use v1 for grants. This is because PVHVM
is not able to use v2 due to no XENMEM_add_to_physmap
calls on the error status page (see commit
69e8f430e2
 xen/granttable: Disable grant v2 for HVM domains.)

Until that is implemented this workaround has to
be in place.

Also per suggestions by Stefano utilize the PVHVM paths
as they share common functionality.

v2 of this patch moves most of the PVH code out in the
arch/x86/xen/grant-table driver and touches only minimally
the generic driver.

v3, v4: fixes us some of the code due to earlier patches.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2014-01-06 10:44:21 -05:00
Mukesh Rathor 2771374d47 xen/pvh: Piggyback on PVHVM for event channels (v2)
PVH is a PV guest with a twist - there are certain things
that work in it like HVM and some like PV. There is
a similar mode - PVHVM where we run in HVM mode with
PV code enabled - and this patch explores that.

The most notable PV interfaces are the XenBus and event channels.

We will piggyback on how the event channel mechanism is
used in PVHVM - that is we want the normal native IRQ mechanism
and we will install a vector (hvm callback) for which we
will call the event channel mechanism.

This means that from a pvops perspective, we can use
native_irq_ops instead of the Xen PV specific. Albeit in the
future we could support pirq_eoi_map. But that is
a feature request that can be shared with PVHVM.

Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2014-01-06 10:44:15 -05:00
Mukesh Rathor 9103bb0f82 xen/pvh: Update E820 to work with PVH (v2)
In xen_add_extra_mem() we can skip updating P2M as it's managed
by Xen. PVH maps the entire IO space, but only RAM pages need
to be repopulated.

Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2014-01-06 10:44:13 -05:00
Mukesh Rathor 5840c84b16 xen/pvh: Secondary VCPU bringup (non-bootup CPUs)
The VCPU bringup protocol follows the PV with certain twists.
From xen/include/public/arch-x86/xen.h:

Also note that when calling DOMCTL_setvcpucontext and VCPU_initialise
for HVM and PVH guests, not all information in this structure is updated:

 - For HVM guests, the structures read include: fpu_ctxt (if
 VGCT_I387_VALID is set), flags, user_regs, debugreg[*]

 - PVH guests are the same as HVM guests, but additionally use ctrlreg[3] to
 set cr3. All other fields not used should be set to 0.

This is what we do. We piggyback on the 'xen_setup_gdt' - but modify
a bit - we need to call 'load_percpu_segment' so that 'switch_to_new_gdt'
can load per-cpu data-structures. It has no effect on the VCPU0.

We also piggyback on the %rdi register to pass in the CPU number - so
that when we bootup a new CPU, the cpu_bringup_and_idle will have
passed as the first parameter the CPU number (via %rdi for 64-bit).

Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2014-01-06 10:44:12 -05:00
Mukesh Rathor 8d656bbe43 xen/pvh: Load GDT/GS in early PV bootup code for BSP.
During early bootup we start life using the Xen provided
GDT, which means that we are running with %cs segment set
to FLAT_KERNEL_CS (FLAT_RING3_CS64 0xe033, GDT index 261).

But for PVH we want to be use HVM type mechanism for
segment operations. As such we need to switch to the HVM
one and also reload ourselves with the __KERNEL_CS:eip
to run in the proper GDT and segment.

For HVM this is usually done in 'secondary_startup_64' in
(head_64.S) but since we are not taking that bootup
path (we start in PV - xen_start_kernel) we need to do
that in the early PV bootup paths.

For good measure we also zero out the %fs, %ds, and %es
(not strictly needed as Xen has already cleared them
for us). The %gs is loaded by 'switch_to_new_gdt'.

Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
2014-01-06 10:44:10 -05:00
Mukesh Rathor 4dd322bc3b xen/pvh: Setup up shared_info.
For PVHVM the shared_info structure is provided via the same way
as for normal PV guests (see include/xen/interface/xen.h).

That is during bootup we get 'xen_start_info' via the %esi register
in startup_xen. Then later we extract the 'shared_info' from said
structure (in xen_setup_shared_info) and start using it.

The 'xen_setup_shared_info' is all setup to work with auto-xlat
guests, but there are two functions which it calls that are not:
xen_setup_mfn_list_list and xen_setup_vcpu_info_placement.
This patch modifies the P2M code (xen_setup_mfn_list_list)
while the "Piggyback on PVHVM for event channels" modifies
the xen_setup_vcpu_info_placement.

Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2014-01-06 10:44:09 -05:00
Mukesh Rathor 76bcceff0b xen/pvh/mmu: Use PV TLB instead of native.
We also optimize one - the TLB flush. The native operation would
needlessly IPI offline VCPUs causing extra wakeups. Using the
Xen one avoids that and lets the hypervisor determine which
VCPU needs the TLB flush.

Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2014-01-06 10:44:07 -05:00
Mukesh Rathor 4e44e44b0b xen/pvh: MMU changes for PVH (v2)
.. which are surprisingly small compared to the amount for PV code.

PVH uses mostly native mmu ops, we leave the generic (native_*) for
the majority and just overwrite the baremetal with the ones we need.

At startup, we are running with pre-allocated page-tables
courtesy of the tool-stack. But we still need to graft them
in the Linux initial pagetables. However there is no need to
unpin/pin and change them to R/O or R/W.

Note that the xen_pagetable_init due to 7836fec9d0994cc9c9150c5a33f0eb0eb08a335a
"xen/mmu/p2m: Refactor the xen_pagetable_init code." does not
need any changes - we just need to make sure that xen_post_allocator_init
does not alter the pvops from the default native one.

Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2014-01-06 10:44:05 -05:00
Konrad Rzeszutek Wilk b621e157ba xen/mmu: Cleanup xen_pagetable_p2m_copy a bit.
Stefano noticed that the code runs only under 64-bit so
the comments about 32-bit are pointless.

Also we change the condition for xen_revector_p2m_tree
returning the same value (because it could not allocate
a swath of space to put the new P2M in) or it had been
called once already. In such we return early from the
function.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2014-01-06 10:44:04 -05:00
Konrad Rzeszutek Wilk 32df75cd14 xen/mmu/p2m: Refactor the xen_pagetable_init code (v2).
The revectoring and copying of the P2M only happens when
!auto-xlat and on 64-bit builds. It is not obvious from
the code, so lets have seperate 32 and 64-bit functions.

We also invert the check for auto-xlat to make the code
flow simpler.

Suggested-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2014-01-06 10:44:02 -05:00
Konrad Rzeszutek Wilk 696fd7c5b2 xen/pvh: Don't setup P2M tree.
P2M is not available for PVH. Fortunatly for us the
P2M code already has mostly the support for auto-xlat guest thanks to
commit 3d24bbd7dd
"grant-table: call set_phys_to_machine after mapping grant refs"
which: "
introduces set_phys_to_machine calls for auto_translated guests
(even on x86) in gnttab_map_refs and gnttab_unmap_refs.
translated by swiotlb-xen... " so we don't need to muck much.

with above mentioned "commit you'll get set_phys_to_machine calls
from gnttab_map_refs and gnttab_unmap_refs but PVH guests won't do
anything with them " (Stefano Stabellini) which is OK - we want
them to be NOPs.

This is because we assume that an "IOMMU is always present on the
plaform and Xen is going to make the appropriate IOMMU pagetable
changes in the hypercall implementation of GNTTABOP_map_grant_ref
and GNTTABOP_unmap_grant_ref, then eveything should be transparent
from PVH priviligied point of view and DMA transfers involving
foreign pages keep working with no issues[sp]

Otherwise we would need a P2M (and an M2P) for PVH priviligied to
track these foreign pages .. (see arch/arm/xen/p2m.c)."
(Stefano Stabellini).

We still have to inhibit the building of the P2M tree.
That had been done in the past by not calling
xen_build_dynamic_phys_to_machine (which setups the P2M tree
and gives us virtual address to access them). But we are missing
a check for xen_build_mfn_list_list - which was continuing to setup
the P2M tree and would blow up at trying to get the virtual
address of p2m_missing (which would have been setup by
xen_build_dynamic_phys_to_machine).

Hence a check is needed to not call xen_build_mfn_list_list when
running in auto-xlat mode.

Instead of replicating the check for auto-xlat in enlighten.c
do it in the p2m.c code. The reason is that the xen_build_mfn_list_list
is called also in xen_arch_post_suspend without any checks for
auto-xlat. So for PVH or PV with auto-xlat - we would needlessly
allocate space for an P2M tree.

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

Without the filtering we expose to the guest the:

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

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

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

Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2014-01-06 10:43:59 -05:00
Mukesh Rathor ddc416cbc4 xen/pvh/x86: Define what an PVH guest is (v3).
Which is a PV guest with auto page translation enabled
and with vector callback. It is a cross between PVHVM and PV.

The Xen side defines PVH as (from docs/misc/pvh-readme.txt,
with modifications):

"* the guest uses auto translate:
 - p2m is managed by Xen
 - pagetables are owned by the guest
 - mmu_update hypercall not available
* it uses event callback and not vlapic emulation,
* IDT is native, so set_trap_table hcall is also N/A for a PVH guest.

For a full list of hcalls supported for PVH, see pvh_hypercall64_table
in arch/x86/hvm/hvm.c in xen.  From the ABI prespective, it's mostly a
PV guest with auto translate, although it does use hvm_op for setting
callback vector."

Also we use the PV cpuid, albeit we can use the HVM (native) cpuid.
However, we do have a fair bit of filtering in the xen_cpuid and
we can piggyback on that until the hypervisor/toolstack filters
the appropiate cpuids. Once that is done we can swap over to
use the native one.

We setup a Kconfig entry that is disabled by default and
cannot be enabled.

Note that on ARM the concept of PVH is non-existent. As Ian
put it: "an ARM guest is neither PV nor HVM nor PVHVM.
It's a bit like PVH but is different also (it's further towards
the H end of the spectrum than even PVH).". As such these
options (PVHVM, PVH) are never enabled nor seen on ARM
compilations.

Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2014-01-06 10:43:58 -05:00
David Vrabel 8785c67663 xen/x86: set VIRQ_TIMER priority to maximum
Commit bee980d9e (xen/events: Handle VIRQ_TIMER before any other hardirq
in event loop) effectively made the VIRQ_TIMER the highest priority event
when using the 2-level ABI.

Set the VIRQ_TIMER priority to the highest so this behaviour is retained
when using the FIFO-based ABI.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2014-01-06 10:07:55 -05:00
Konrad Rzeszutek Wilk 6f6c15ef91 xen/pvhvm: Remove the xen_platform_pci int.
Since we have  xen_has_pv_devices,xen_has_pv_disk_devices,
xen_has_pv_nic_devices, and xen_has_pv_and_legacy_disk_devices
to figure out the different 'unplug' behaviors - lets
use those instead of this single int.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2014-01-03 14:54:53 -05:00
Konrad Rzeszutek Wilk 51c71a3bba xen/pvhvm: If xen_platform_pci=0 is set don't blow up (v4).
The user has the option of disabling the platform driver:
00:02.0 Unassigned class [ff80]: XenSource, Inc. Xen Platform Device (rev 01)

which is used to unplug the emulated drivers (IDE, Realtek 8169, etc)
and allow the PV drivers to take over. If the user wishes
to disable that they can set:

  xen_platform_pci=0
  (in the guest config file)

or
  xen_emul_unplug=never
  (on the Linux command line)

except it does not work properly. The PV drivers still try to
load and since the Xen platform driver is not run - and it
has not initialized the grant tables, most of the PV drivers
stumble upon:

input: Xen Virtual Keyboard as /devices/virtual/input/input5
input: Xen Virtual Pointer as /devices/virtual/input/input6M
------------[ cut here ]------------
kernel BUG at /home/konrad/ssd/konrad/linux/drivers/xen/grant-table.c:1206!
invalid opcode: 0000 [#1] SMP
Modules linked in: xen_kbdfront(+) xenfs xen_privcmd
CPU: 6 PID: 1389 Comm: modprobe Not tainted 3.13.0-rc1upstream-00021-ga6c892b-dirty #1
Hardware name: Xen HVM domU, BIOS 4.4-unstable 11/26/2013
RIP: 0010:[<ffffffff813ddc40>]  [<ffffffff813ddc40>] get_free_entries+0x2e0/0x300
Call Trace:
 [<ffffffff8150d9a3>] ? evdev_connect+0x1e3/0x240
 [<ffffffff813ddd0e>] gnttab_grant_foreign_access+0x2e/0x70
 [<ffffffffa0010081>] xenkbd_connect_backend+0x41/0x290 [xen_kbdfront]
 [<ffffffffa0010a12>] xenkbd_probe+0x2f2/0x324 [xen_kbdfront]
 [<ffffffff813e5757>] xenbus_dev_probe+0x77/0x130
 [<ffffffff813e7217>] xenbus_frontend_dev_probe+0x47/0x50
 [<ffffffff8145e9a9>] driver_probe_device+0x89/0x230
 [<ffffffff8145ebeb>] __driver_attach+0x9b/0xa0
 [<ffffffff8145eb50>] ? driver_probe_device+0x230/0x230
 [<ffffffff8145eb50>] ? driver_probe_device+0x230/0x230
 [<ffffffff8145cf1c>] bus_for_each_dev+0x8c/0xb0
 [<ffffffff8145e7d9>] driver_attach+0x19/0x20
 [<ffffffff8145e260>] bus_add_driver+0x1a0/0x220
 [<ffffffff8145f1ff>] driver_register+0x5f/0xf0
 [<ffffffff813e55c5>] xenbus_register_driver_common+0x15/0x20
 [<ffffffff813e76b3>] xenbus_register_frontend+0x23/0x40
 [<ffffffffa0015000>] ? 0xffffffffa0014fff
 [<ffffffffa001502b>] xenkbd_init+0x2b/0x1000 [xen_kbdfront]
 [<ffffffff81002049>] do_one_initcall+0x49/0x170

.. snip..

which is hardly nice. This patch fixes this by having each
PV driver check for:
 - if running in PV, then it is fine to execute (as that is their
   native environment).
 - if running in HVM, check if user wanted 'xen_emul_unplug=never',
   in which case bail out and don't load any PV drivers.
 - if running in HVM, and if PCI device 5853:0001 (xen_platform_pci)
   does not exist, then bail out and not load PV drivers.
 - (v2) if running in HVM, and if the user wanted 'xen_emul_unplug=ide-disks',
   then bail out for all PV devices _except_ the block one.
   Ditto for the network one ('nics').
 - (v2) if running in HVM, and if the user wanted 'xen_emul_unplug=unnecessary'
   then load block PV driver, and also setup the legacy IDE paths.
   In (v3) make it actually load PV drivers.

Reported-by: Sander Eikelenboom <linux@eikelenboom.it
Reported-by: Anthony PERARD <anthony.perard@citrix.com>
Reported-and-Tested-by: Fabio Fantoni <fabio.fantoni@m2r.biz>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[v2: Add extra logic to handle the myrid ways 'xen_emul_unplug'
can be used per Ian and Stefano suggestion]
[v3: Make the unnecessary case work properly]
[v4: s/disks/ide-disks/ spotted by Fabio]
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com> [for PCI parts]
CC: stable@vger.kernel.org
2014-01-03 14:54:18 -05:00
Linus Torvalds eda670c626 Features:
- SWIOTLB has tracing added when doing bounce buffer.
  - Xen ARM/ARM64 can use Xen-SWIOTLB. This work allows Linux to
    safely program real devices for DMA operations when running as
    a guest on Xen on ARM, without IOMMU support.*1
  - xen_raw_printk works with PVHVM guests if needed.
 Bug-fixes:
  - Make memory ballooning work under HVM with large MMIO region.
  - Inform hypervisor of MCFG regions found in ACPI DSDT.
  - Remove deprecated IRQF_DISABLED.
  - Remove deprecated __cpuinit.
 
 [*1]:
 "On arm and arm64 all Xen guests, including dom0, run with second stage
 translation enabled. As a consequence when dom0 programs a device for a
 DMA operation is going to use (pseudo) physical addresses instead
 machine addresses. This work introduces two trees to track physical to
 machine and machine to physical mappings of foreign pages. Local pages
 are assumed mapped 1:1 (physical address == machine address).  It
 enables the SWIOTLB-Xen driver on ARM and ARM64, so that Linux can
 translate physical addresses to machine addresses for dma operations
 when necessary. " (Stefano).
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1.4.15 (GNU/Linux)
 
 iQEcBAABAgAGBQJSgS86AAoJEFjIrFwIi8fJpY4H/R2gke1A1p9UvTwbkaDhgPs/
 u/mkI6aH+ktgvu5QZNprki660uydtc4Ck7y8leeLGYw+ed1Ys559SJhRc/x8jBYZ
 Hh2chnplld0LAjSpdIDTTePArE1xBo4Gz+fT0zc5cVh0leJwOXn92Kx8N5AWD/T3
 gwH4Ok4K1dzZBIls7imM2AM/L1xcApcx3Dl/QpNcoePQtR4yLuPWMUbb3LM8pbUY
 0B6ZVN4GOhtJ84z8HRKnh4uMnBYmhmky6laTlHVa6L+j1fv7aAPCdNbePjIt/Pvj
 HVYB1O/ht73yHw0zGfK6lhoGG8zlu+Q7sgiut9UsGZZfh34+BRKzNTypqJ3ezQo=
 =xc43
 -----END PGP SIGNATURE-----

Merge tag 'stable/for-linus-3.13-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull Xen updates from Konrad Rzeszutek Wilk:
 "This has tons of fixes and two major features which are concentrated
  around the Xen SWIOTLB library.

  The short <blurb> is that the tracing facility (just one function) has
  been added to SWIOTLB to make it easier to track I/O progress.
  Additionally under Xen and ARM (32 & 64) the Xen-SWIOTLB driver
  "is used to translate physical to machine and machine to physical
  addresses of foreign[guest] pages for DMA operations" (Stefano) when
  booting under hardware without proper IOMMU.

  There are also bug-fixes, cleanups, compile warning fixes, etc.

  The commit times for some of the commits is a bit fresh - that is b/c
  we wanted to make sure we have the Ack's from the ARM folks - which
  with the string of back-to-back conferences took a bit of time.  Rest
  assured - the code has been stewing in #linux-next for some time.

  Features:
   - SWIOTLB has tracing added when doing bounce buffer.
   - Xen ARM/ARM64 can use Xen-SWIOTLB.  This work allows Linux to
     safely program real devices for DMA operations when running as a
     guest on Xen on ARM, without IOMMU support. [*1]
   - xen_raw_printk works with PVHVM guests if needed.

  Bug-fixes:
   - Make memory ballooning work under HVM with large MMIO region.
   - Inform hypervisor of MCFG regions found in ACPI DSDT.
   - Remove deprecated IRQF_DISABLED.
   - Remove deprecated __cpuinit.

  [*1]:
  "On arm and arm64 all Xen guests, including dom0, run with second
   stage translation enabled.  As a consequence when dom0 programs a
   device for a DMA operation is going to use (pseudo) physical
   addresses instead machine addresses.  This work introduces two trees
   to track physical to machine and machine to physical mappings of
   foreign pages.  Local pages are assumed mapped 1:1 (physical address
   == machine address).  It enables the SWIOTLB-Xen driver on ARM and
   ARM64, so that Linux can translate physical addresses to machine
   addresses for dma operations when necessary.  " (Stefano)"

* tag 'stable/for-linus-3.13-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (32 commits)
  xen/arm: pfn_to_mfn and mfn_to_pfn return the argument if nothing is in the p2m
  arm,arm64/include/asm/io.h: define struct bio_vec
  swiotlb-xen: missing include dma-direction.h
  pci-swiotlb-xen: call pci_request_acs only ifdef CONFIG_PCI
  arm: make SWIOTLB available
  xen: delete new instances of added __cpuinit
  xen/balloon: Set balloon's initial state to number of existing RAM pages
  xen/mcfg: Call PHYSDEVOP_pci_mmcfg_reserved for MCFG areas.
  xen: remove deprecated IRQF_DISABLED
  x86/xen: remove deprecated IRQF_DISABLED
  swiotlb-xen: fix error code returned by xen_swiotlb_map_sg_attrs
  swiotlb-xen: static inline xen_phys_to_bus, xen_bus_to_phys, xen_virt_to_bus and range_straddles_page_boundary
  grant-table: call set_phys_to_machine after mapping grant refs
  arm,arm64: do not always merge biovec if we are running on Xen
  swiotlb: print a warning when the swiotlb is full
  swiotlb-xen: use xen_dma_map/unmap_page, xen_dma_sync_single_for_cpu/device
  xen: introduce xen_dma_map/unmap_page and xen_dma_sync_single_for_cpu/device
  tracing/events: Fix swiotlb tracepoint creation
  swiotlb-xen: use xen_alloc/free_coherent_pages
  xen: introduce xen_alloc/free_coherent_pages
  ...
2013-11-15 13:34:37 +09:00
Kirill A. Shutemov 49076ec2cc mm: dynamically allocate page->ptl if it cannot be embedded to struct page
If split page table lock is in use, we embed the lock into struct page
of table's page.  We have to disable split lock, if spinlock_t is too
big be to be embedded, like when DEBUG_SPINLOCK or DEBUG_LOCK_ALLOC
enabled.

This patch add support for dynamic allocation of split page table lock
if we can't embed it to struct page.

page->ptl is unsigned long now and we use it as spinlock_t if
sizeof(spinlock_t) <= sizeof(long), otherwise it's pointer to spinlock_t.

The spinlock_t allocated in pgtable_page_ctor() for PTE table and in
pgtable_pmd_page_ctor() for PMD table.  All other helpers converted to
support dynamically allocated page->ptl.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-15 09:32:20 +09:00
Kirill A. Shutemov 57c1ffcefb mm: rename USE_SPLIT_PTLOCKS to USE_SPLIT_PTE_PTLOCKS
We're going to introduce split page table lock for PMD level.  Let's
rename existing split ptlock for PTE level to avoid confusion.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Tested-by: Alex Thorlton <athorlton@sgi.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Jones <davej@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Robin Holt <robinmholt@gmail.com>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-15 09:32:14 +09:00
Konrad Rzeszutek Wilk e1d8f62ad4 Merge remote-tracking branch 'stefano/swiotlb-xen-9.1' into stable/for-linus-3.13
* stefano/swiotlb-xen-9.1:
  swiotlb-xen: fix error code returned by xen_swiotlb_map_sg_attrs
  swiotlb-xen: static inline xen_phys_to_bus, xen_bus_to_phys, xen_virt_to_bus and range_straddles_page_boundary
  grant-table: call set_phys_to_machine after mapping grant refs
  arm,arm64: do not always merge biovec if we are running on Xen
  swiotlb: print a warning when the swiotlb is full
  swiotlb-xen: use xen_dma_map/unmap_page, xen_dma_sync_single_for_cpu/device
  xen: introduce xen_dma_map/unmap_page and xen_dma_sync_single_for_cpu/device
  swiotlb-xen: use xen_alloc/free_coherent_pages
  xen: introduce xen_alloc/free_coherent_pages
  arm64/xen: get_dma_ops: return xen_dma_ops if we are running as xen_initial_domain
  arm/xen: get_dma_ops: return xen_dma_ops if we are running as xen_initial_domain
  swiotlb-xen: introduce xen_swiotlb_set_dma_mask
  xen/arm,arm64: enable SWIOTLB_XEN
  xen: make xen_create_contiguous_region return the dma address
  xen/x86: allow __set_phys_to_machine for autotranslate guests
  arm/xen,arm64/xen: introduce p2m
  arm64: define DMA_ERROR_CODE
  arm: make SWIOTLB available

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Conflicts:
	arch/arm/include/asm/dma-mapping.h
	drivers/xen/swiotlb-xen.c

[Conflicts arose b/c "arm: make SWIOTLB available" v8 was in Stefano's
branch, while I had v9 + Ack from Russel. I also fixed up white-space
issues]
2013-11-08 16:10:48 -05:00
Stefano Stabellini 92c0fd17c0 pci-swiotlb-xen: call pci_request_acs only ifdef CONFIG_PCI
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-11-08 15:21:44 -05:00
Paul Gortmaker 3b284bde70 xen: delete new instances of added __cpuinit
commit 6efa20e49b
("xen: Support 64-bit PV guest receiving NMIs") and
commit cd9151e26d
( "xen/balloon: set a mapping for ballooned out pages")
added new instances of __cpuinit usage.

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

Cc: Konrad Rzeszutek Wilk <konrad@kernel.org>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-11-08 15:13:16 -05:00
Michael Opdenacker 9d71cee667 x86/xen: remove deprecated IRQF_DISABLED
This patch proposes to remove the IRQF_DISABLED flag from x86/xen
code. It's a NOOP since 2.6.35 and it will be removed one day.

Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-11-06 15:31:01 -05:00
Frediano Ziglio 7cde9b27e7 xen: Fix possible user space selector corruption
Due to the way kernel is initialized under Xen is possible that the
ring1 selector used by the kernel for the boot cpu end up to be copied
to userspace leading to segmentation fault in the userspace.

Xen code in the kernel initialize no-boot cpus with correct selectors (ds
and es set to __USER_DS) but the boot one keep the ring1 (passed by Xen).
On task context switch (switch_to) we assume that ds, es and cs already
point to __USER_DS and __KERNEL_CSso these selector are not changed.

If processor is an Intel that support sysenter instruction sysenter/sysexit
is used so ds and es are not restored switching back from kernel to
userspace. In the case the selectors point to a ring1 instead of __USER_DS
the userspace code will crash on first memory access attempt (to be
precise Xen on the emulated iret used to do sysexit will detect and set ds
and es to zero which lead to GPF anyway).

Now if an userspace process call kernel using sysenter and get rescheduled
(for me it happen on a specific init calling wait4) could happen that the
ring1 selector is set to ds and es.

This is quite hard to detect cause after a while these selectors are fixed
(__USER_DS seems sticky).

Bisecting the code commit 7076aada10 appears
to be the first one that have this issue.

Signed-off-by: Frediano Ziglio <frediano.ziglio@citrix.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
2013-10-10 14:39:37 +00:00
Stefano Stabellini 1b65c4e5a9 swiotlb-xen: use xen_alloc/free_coherent_pages
Use xen_alloc_coherent_pages and xen_free_coherent_pages to allocate or
free coherent pages.

We need to be careful handling the pointer returned by
xen_alloc_coherent_pages, because on ARM the pointer is not equal to
phys_to_virt(*dma_handle). In fact virt_to_phys only works for kernel
direct mapped RAM memory.
In ARM case the pointer could be an ioremap address, therefore passing
it to virt_to_phys would give you another physical address that doesn't
correspond to it.

Make xen_create_contiguous_region take a phys_addr_t as start parameter to
avoid the virt_to_phys calls which would be incorrect.

Changes in v6:
- remove extra spaces.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-10-10 13:41:10 +00:00
Stefano Stabellini 69908907b0 xen: make xen_create_contiguous_region return the dma address
Modify xen_create_contiguous_region to return the dma address of the
newly contiguous buffer.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>


Changes in v4:
- use virt_to_machine instead of virt_to_bus.
2013-10-09 16:56:32 +00:00
Stefano Stabellini 2f558d4091 xen/x86: allow __set_phys_to_machine for autotranslate guests
Allow __set_phys_to_machine to be called for autotranslate guests.
It can be used to keep track of phys_to_machine changes, however we
don't do anything with the information at the moment.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2013-10-09 20:39:01 +00:00
Konrad Rzeszutek Wilk b1922a519e xen/mmu: Correct PAT MST setting.
Jan Beulich spotted that the PAT MSR settings in the Xen public
document that "the first (PAT6) column was wrong across the
board, and the column for PAT7 was missing altogether."

This updates it to be in sync.

CC: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
2013-09-27 09:04:45 -04:00
Linus Torvalds 4b97280675 Bug-fixes:
- Fix PV spinlocks triggering jump_label code bug
  - Remove extraneous code in the tpm front driver
  - Fix ballooning out of pages when non-preemptible
  - Fix deadlock when using a 32-bit initial domain with large amount of memory.
  - Add xen_nopvpsin parameter to the documentation
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1.4.14 (GNU/Linux)
 
 iQEcBAABAgAGBQJSQvzCAAoJEFjIrFwIi8fJyCIIAMENABapdLhrOiRdQ1Y7T5v1
 4bogPDLwpVxHzwo/vnHcNpl35/dUZrC6wQa51Bkoqq0V8o1XmjFy3SY/EBGjEAvw
 hh4qxGY0p0NNi6hKrWC8mH9u2TcluZGm1uecabkXUhl9mrAB5oBsfJdbBZ5N69gO
 QXXt0j7Xwv1APwH86T0e1Lz+lulhdw2ItXP4osYkEbRYNSaaGnuwsd0Jxcb4DeMk
 qhKgP7QMn3C7zDDaapJo1axeYQRBNEtv5M8+0wwMleX4yX1+IBRZeQTsRfMr7RB/
 8FhssWiH15xU6Gmzgi/VR8xhTEIbQh5GWsVReGf6pqIYSxGSYTvvyhm0bVRH4JI=
 =c+7u
 -----END PGP SIGNATURE-----

Merge tag 'stable/for-linus-3.12-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull Xen fixes from Konrad Rzeszutek Wilk:
 "Bug-fixes and one update to the kernel-paramters.txt documentation.

   - Fix PV spinlocks triggering jump_label code bug
   - Remove extraneous code in the tpm front driver
   - Fix ballooning out of pages when non-preemptible
   - Fix deadlock when using a 32-bit initial domain with large amount
     of memory
   - Add xen_nopvpsin parameter to the documentation"

* tag 'stable/for-linus-3.12-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/spinlock: Document the xen_nopvspin parameter.
  xen/p2m: check MFN is in range before using the m2p table
  xen/balloon: don't alloc page while non-preemptible
  xen: Do not enable spinlocks before jump_label_init() has executed
  tpm: xen-tpmfront: Remove the locality sysfs attribute
  tpm: xen-tpmfront: Fix default durations
2013-09-25 15:50:53 -07:00
David Vrabel 0160676bba xen/p2m: check MFN is in range before using the m2p table
On hosts with more than 168 GB of memory, a 32-bit guest may attempt
to grant map an MFN that is error cannot lookup in its mapping of the
m2p table.  There is an m2p lookup as part of m2p_add_override() and
m2p_remove_override().  The lookup falls off the end of the mapped
portion of the m2p and (because the mapping is at the highest virtual
address) wraps around and the lookup causes a fault on what appears to
be a user space address.

do_page_fault() (thinking it's a fault to a userspace address), tries
to lock mm->mmap_sem.  If the gntdev device is used for the grant map,
m2p_add_override() is called from from gnttab_mmap() with mm->mmap_sem
already locked.  do_page_fault() then deadlocks.

The deadlock would most commonly occur when a 64-bit guest is started
and xenconsoled attempts to grant map its console ring.

Introduce mfn_to_pfn_no_overrides() which checks the MFN is within the
mapped portion of the m2p table before accessing the table and use
this in m2p_add_override(), m2p_remove_override(), and mfn_to_pfn()
(which already had the correct range check).

All faults caused by accessing the non-existant parts of the m2p are
thus within the kernel address space and exception_fixup() is called
without trying to lock mm->mmap_sem.

This means that for MFNs that are outside the mapped range of the m2p
then mfn_to_pfn() will always look in the m2p overrides.  This is
correct because it must be a foreign MFN (and the PFN in the m2p in
this case is only relevant for the other domain).

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Cc: Stefano Stabellini <stefano.stabellini@citrix.com>
Cc: Jan Beulich <JBeulich@suse.com>
--
v3: check for auto_translated_physmap in mfn_to_pfn_no_overrides()
v2: in mfn_to_pfn() look in m2p_overrides if the MFN is out of
    range as it's probably foreign.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2013-09-25 09:00:03 -04:00
Konrad Rzeszutek Wilk a945928ea2 xen: Do not enable spinlocks before jump_label_init() has executed
xen_init_spinlocks() currently calls static_key_slow_inc() before
jump_label_init() is invoked. When CONFIG_JUMP_LABEL is set (which usually is
the case) the effect of this static_key_slow_inc() is deferred until after
jump_label_init(). This is different from when CONFIG_JUMP_LABEL is not set, in
which case the key is set immediately. Thus, depending on the value of config
option, we may observe different behavior.

In addition, when we come to __jump_label_transform() from jump_label_init(),
the key (paravirt_ticketlocks_enabled) is already enabled. On processors where
ideal_nop is not the same as default_nop this will cause a BUG() since it is
expected that before a key is enabled the latter is replaced by the former
during initialization.

To address this problem we need to move
static_key_slow_inc(&paravirt_ticketlocks_enabled) so that it is called
after jump_label_init(). We also need to make sure that this is done before
other cpus start to boot. early_initcall appears to be  a good place to do so.
(Note that we cannot move whole xen_init_spinlocks() there since pv_lock_ops
need to be set before alternative_instructions() runs.)

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[v2: Added extra comments in the code]
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
2013-09-24 16:22:26 -04:00
Linus Torvalds a60d4b9874 Bug-fixes:
- Boot on ARM without using Xen unconditionally
  - On Xen ARM don't run cpuidle/cpufreq
  - Fix regression in balloon driver, preempt count warnings
  - Fixes to make PVHVM able to use pv ticketlock.
  - Revert Xen PVHVM disabling pv ticketlock (aka, re-enable pv ticketlocks)
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1.4.14 (GNU/Linux)
 
 iQEcBAABAgAGBQJSLhcPAAoJEFjIrFwIi8fJGq8IAIxI9zcnY9N6eaD3DepdZlz9
 AMT8/k7afau1rDMk5r3HaUjAkdeEvCgeWw8W6tJ+OK19AmFTVEvoO803MSzYkDol
 6XoknSoU9UnE+/w4FF1FttWmRxkZ8Op/hcs9435q7o+L0zlk9CbbkxFlzUKf5yVD
 KfvQED4D/ShmPj2f+jYLCtsIi1m/AJ36BsfaUtJo3QVKvJIFFbT6F1AJ4tlbmvC0
 FOaHYl9cTlPXfrpwviIP0+W8RVmcWreLqSOKsdHuWzB//MSvZDVmLGc7JPorblfe
 cuME/tF/Y5bnxHKp8Es2MczpdvS6yp/HNoe0g6AdLVPL7dvGPqKpf2uZZNXUawQ=
 =qpSg
 -----END PGP SIGNATURE-----

Merge tag 'stable/for-linus-3.12-rc0-tag-two' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull Xen bug-fixes from Konrad Rzeszutek Wilk:
 "This pull I usually do after rc1 is out but because we have a nice
  amount of fixes, some bootup related fixes for ARM, and it is early in
  the cycle we figured to do it now to help with tracking of potential
  regressions.

  The simple ones are the ARM ones - one of the patches fell through the
  cracks, other fixes a bootup issue (unconditionally using Xen
  functions).  Then a fix for a regression causing preempt count being
  off (patch causing this went in v3.12).

  Lastly are the fixes to make Xen PVHVM guests use PV ticketlocks (Xen
  PV already does).

  The enablement of that was supposed to be part of the x86 spinlock
  merge in commit 816434ec4a ("The biggest change here are
  paravirtualized ticket spinlocks (PV spinlocks), which bring a nice
  speedup on various benchmarks...") but unfortunatly it would cause
  hang when booting Xen PVHVM guests.  Yours truly got all of the bugs
  fixed last week and they (six of them) are included in this pull.

  Bug-fixes:
   - Boot on ARM without using Xen unconditionally
   - On Xen ARM don't run cpuidle/cpufreq
   - Fix regression in balloon driver, preempt count warnings
   - Fixes to make PVHVM able to use pv ticketlock.
   - Revert Xen PVHVM disabling pv ticketlock (aka, re-enable pv ticketlocks)"

* tag 'stable/for-linus-3.12-rc0-tag-two' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/spinlock: Don't use __initdate for xen_pv_spin
  Revert "xen/spinlock: Disable IRQ spinlock (PV) allocation on PVHVM"
  xen/spinlock: Don't setup xen spinlock IPI kicker if disabled.
  xen/smp: Update pv_lock_ops functions before alternative code starts under PVHVM
  xen/spinlock: We don't need the old structure anymore
  xen/spinlock: Fix locking path engaging too soon under PVHVM.
  xen/arm: disable cpuidle and cpufreq when linux is running as dom0
  xen/p2m: Don't call get_balloon_scratch_page() twice, keep interrupts disabled for multicalls
  ARM: xen: only set pm function ptrs for Xen guests
2013-09-10 20:07:04 -07:00
Konrad Rzeszutek Wilk c3b7cb1fd8 xen/spinlock: Don't use __initdate for xen_pv_spin
As we get compile warnings about .init.data being
used by non-init functions.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-09-09 13:08:49 -04:00
Konrad Rzeszutek Wilk fb78e58c27 Revert "xen/spinlock: Disable IRQ spinlock (PV) allocation on PVHVM"
This reverts commit 70dd4998cb.

Now that the bugs have been resolved we can re-enable the
PV ticketlock implementation under PVHVM Xen guests.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
2013-09-09 12:06:45 -04:00
Konrad Rzeszutek Wilk 3310bbedac xen/spinlock: Don't setup xen spinlock IPI kicker if disabled.
There is no need to setup this kicker IPI if we are never going
to use the paravirtualized ticketlock mechanism.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
2013-09-09 12:06:38 -04:00