Set the callback to receive evtchns from Xen, using the
callback vector delivery mechanism.
The traditional way for receiving event channel notifications from Xen
is via the interrupts from the platform PCI device.
The callback vector is a newer alternative that allow us to receive
notifications on any vcpu and doesn't need any PCI support: we allocate
a vector exclusively to receive events, in the vector handler we don't
need to interact with the vlapic, therefore we avoid a VMEXIT.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Initialize basic pv on hvm features adding a new Xen HVM specific
hypervisor_x86 structure.
Don't try to initialize xen-kbdfront and xen-fbfront when running on HVM
because the backends are not available.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Scan the set of pages we're freeing and make sure they're actually
owned by the domain before freeing. This generally won't happen on a
domU (since Xen gives us contigious memory), but it could happen if
there are some hardware mappings passed through.
We only bother going up to the highest page Xen actually claimed to
give us, since there's definitely nothing of ours above that.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Scan an e820 table and release any memory which lies between e820 entries,
as it won't be used and would just be wasted. At present this is just to
release any memory beyond the end of the e820 map, but it will also deal
with holes being punched in the map.
Derived from patch by Miroslav Rezanina <mrezanin@redhat.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
A memory region must be physically contiguous in order to be accessed
through DMA. This patch adds xen_create_contiguous_region, which
ensures a region of contiguous virtual memory is also physically
contiguous.
Based on Stephen Tweedie's port of the 2.6.18-xen version.
Remove contiguous_bitmap[] as it's no longer needed.
Ported from linux-2.6.18-xen.hg 707:e410857fd83c
[ Impact: add Xen-internal API to make pages phys-contig ]
Signed-off-by: Alex Nixon <alex.nixon@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* xen_create_contiguous_region needs access to the balloon lock to
ensure memory doesn't change under its feet, so expose the balloon
lock
* Change the name of the lock to xen_reservation_lock, to imply it's
now less-specific usage.
[ Impact: cleanup ]
Signed-off-by: Alex Nixon <alex.nixon@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
PV DomU domains are allowed to map hardware MFNs for PCI passthrough,
but are not generally allowed to map raw machine pages. In particular,
various pieces of code try to map DMI and ACPI tables in the ISA ROM
range. We disallow _PAGE_IOMAP for those mappings, so that they are
redirected to a set of local zeroed pages we reserve for that purpose.
[ Impact: prevent passthrough of ISA space, as we only allow PCI ]
Signed-off-by: Alex Nixon <alex.nixon@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
In a Xen domain, ioremap operates on machine addresses, not
pseudo-physical addresses. We use _PAGE_IOMAP to determine whether a
mapping is intended for machine addresses.
[ Impact: allow Xen domain to map real hardware ]
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
The core suspend/resume code is run from stop_machine on CPU0 but
parts of the suspend/resume machinery (including xen_arch_resume) are
run on whichever CPU happened to schedule the xenwatch kernel thread.
As part of the non-core resume code xen_arch_resume is called in order
to restart the timer tick on non-boot processors. The boot processor
itself is taken care of by core timekeeping code.
xen_arch_resume uses smp_call_function which does not call the given
function on the current processor. This means that we can end up with
one CPU not receiving timer ticks if the xenwatch thread happened to
be scheduled on CPU > 0.
Use on_each_cpu instead of smp_call_function to ensure the timer tick
is resumed everywhere.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Stable Kernel <stable@kernel.org> # .32.x
* 'timers-for-linus-cleanups' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
avr32: Fix typo in read_persistent_clock()
sparc: Convert sparc to use read/update_persistent_clock
cris: Convert cris to use read/update_persistent_clock
m68k: Convert m68k to use read/update_persistent_clock
m32r: Convert m32r to use read/update_peristent_clock
blackfin: Convert blackfin to use read/update_persistent_clock
ia64: Convert ia64 to use read/update_persistent_clock
avr32: Convert avr32 to use read/update_persistent_clock
h8300: Convert h8300 to use read/update_persistent_clock
frv: Convert frv to use read/update_persistent_clock
mn10300: Convert mn10300 to use read/update_persistent_clock
alpha: Convert alpha to use read/update_persistent_clock
xtensa: Fix unnecessary setting of xtime
time: Clean up direct xtime usage in xen
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cleanup xen's direct use of internal timekeeping values.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Acked-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Now that both Xen and VMI disable allocations of PTE pages from high
memory this paravirt op serves no further purpose.
This effectively reverts ce6234b5 "add kmap_atomic_pte for mapping
highpte pages".
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
LKML-Reference: <1267204562-11844-3-git-send-email-ian.campbell@citrix.com>
Acked-by: Alok Kataria <akataria@vmware.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
There's a path in the pagefault code where the kernel deliberately
breaks its own locking rules by kmapping a high pte page without
holding the pagetable lock (in at least page_check_address). This
breaks Xen's ability to track the pinned/unpinned state of the
page. There does not appear to be a viable workaround for this
behaviour so simply disable HIGHPTE for all Xen guests.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
LKML-Reference: <1267204562-11844-1-git-send-email-ian.campbell@citrix.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Pasi Kärkkäinen <pasik@iki.fi>
Cc: <stable@kernel.org> # .32.x: 14315592: Allow highmem user page tables to be disabled at boot time
Cc: <stable@kernel.org> # .32.x
Cc: <xen-devel@lists.xensource.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Under Xen 64 bit guests actually run their kernel in ring 3,
however the hypervisor takes care of squashing descriptor the
RPLs transparently (in order to allow them to continue to
differentiate between user and kernel space CS using the RPL).
Therefore the Xen paravirt backend should use RPL==0 instead of
1 (or 3). Using RPL==1 causes generic arch code to take
incorrect code paths because it uses "testl $3, <CS>, je foo"
type tests for a userspace CS and this considers 1==userspace.
This issue was previously masked because get_kernel_rpl() was
omitted when setting CS in kernel_thread(). This was fixed when
kernel_thread() was unified with 32 bit in
f443ff4201.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Christian Kujau <lists@nerdbynature.de>
Cc: Jeremy Fitzhardinge <Jeremy.Fitzhardinge@citrix.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Brian Gerst <brgerst@gmail.com>
LKML-Reference: <1263377768-19600-2-git-send-email-ian.campbell@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The raw_spin* namespace was taken by lockdep for the architecture
specific implementations. raw_spin_* would be the ideal name space for
the spinlocks which are not converted to sleeping locks in preempt-rt.
Linus suggested to convert the raw_ to arch_ locks and cleanup the
name space instead of using an artifical name like core_spin,
atomic_spin or whatever
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: linux-arch@vger.kernel.org
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (34 commits)
m68k: rename global variable vmalloc_end to m68k_vmalloc_end
percpu: add missing per_cpu_ptr_to_phys() definition for UP
percpu: Fix kdump failure if booted with percpu_alloc=page
percpu: make misc percpu symbols unique
percpu: make percpu symbols in ia64 unique
percpu: make percpu symbols in powerpc unique
percpu: make percpu symbols in x86 unique
percpu: make percpu symbols in xen unique
percpu: make percpu symbols in cpufreq unique
percpu: make percpu symbols in oprofile unique
percpu: make percpu symbols in tracer unique
percpu: make percpu symbols under kernel/ and mm/ unique
percpu: remove some sparse warnings
percpu: make alloc_percpu() handle array types
vmalloc: fix use of non-existent percpu variable in put_cpu_var()
this_cpu: Use this_cpu_xx in trace_functions_graph.c
this_cpu: Use this_cpu_xx for ftrace
this_cpu: Use this_cpu_xx in nmi handling
this_cpu: Use this_cpu operations in RCU
this_cpu: Use this_cpu ops for VM statistics
...
Fix up trivial (famous last words) global per-cpu naming conflicts in
arch/x86/kvm/svm.c
mm/slab.c
* 'bugfix' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen:
xen: try harder to balloon up under memory pressure.
Xen balloon: fix totalram_pages counting.
xen: explicitly create/destroy stop_machine workqueues outside suspend/resume region.
xen: improve error handling in do_suspend.
xen: don't leak IRQs over suspend/resume.
xen: call clock resume notifier on all CPUs
xen: use iret for return from 64b kernel to 32b usermode
xen: don't call dpm_resume_noirq() with interrupts disabled.
xen: register runstate info for boot CPU early
xen: register runstate on secondary CPUs
xen: register timer interrupt with IRQF_TIMER
xen: correctly restore pfn_to_mfn_list_list after resume
xen: restore runstate_info even if !have_vcpu_info_placement
xen: re-register runstate area earlier on resume.
xen: wait up to 5 minutes for device connetion
xen: improvement to wait_for_devices()
xen: fix is_disconnected_device/exists_disconnected_device
xen/xenbus: make DEVICE_ATTR()s static
* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (36 commits)
x86, mm: Correct the implementation of is_untracked_pat_range()
x86/pat: Trivial: don't create debugfs for memtype if pat is disabled
x86, mtrr: Fix sorting of mtrr after subtracting
x86: Move find_smp_config() earlier and avoid bootmem usage
x86, platform: Change is_untracked_pat_range() to bool; cleanup init
x86: Change is_ISA_range() into an inline function
x86, mm: is_untracked_pat_range() takes a normal semiclosed range
x86, mm: Call is_untracked_pat_range() rather than is_ISA_range()
x86: UV SGI: Don't track GRU space in PAT
x86: SGI UV: Fix BAU initialization
x86, numa: Use near(er) online node instead of roundrobin for NUMA
x86, numa, bootmem: Only free bootmem on NUMA failure path
x86: Change crash kernel to reserve via reserve_early()
x86: Eliminate redundant/contradicting cache line size config options
x86: When cleaning MTRRs, do not fold WP into UC
x86: remove "extern" from function prototypes in <asm/proto.h>
x86, mm: Report state of NX protections during boot
x86, mm: Clean up and simplify NX enablement
x86, pageattr: Make set_memory_(x|nx) aware of NX support
x86, sleep: Always save the value of EFER
...
Fix up conflicts (added both iommu_shutdown and is_untracked_pat_range)
to 'struct x86_platform_ops') in
arch/x86/include/asm/x86_init.h
arch/x86/kernel/x86_init.c
Commit ae21ee65e8 "PCI: acs p2p upsteram
forwarding enabling" doesn't actually enable ACS.
Add a function to pci core to allow an IOMMU to request that ACS
be enabled. The existing mechanism of using iommu_found() in the pci
core to know when ACS should be enabled doesn't actually work due to
initialization order; iommu has only been detected not initialized.
Have Intel and AMD IOMMUs request ACS, and Xen does as well during early
init of dom0.
Cc: Allen Kay <allen.m.kay@intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
tick_resume() is never called on secondary processors. Presumably this
is because they are offlined for suspend on native and so this is
normally taken care of in the CPU onlining path. Under Xen we keep all
CPUs online over a suspend.
This patch papers over the issue for me but I will investigate a more
generic, less hacky, way of doing to the same.
tick_suspend is also only called on the boot CPU which I presume should
be fixed too.
Signed-off-by: Ian Campbell <Ian.Campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
If Xen wants to return to a 32b usermode with sysret it must use the
right form. When using VCGF_in_syscall to trigger this, it looks at
the code segment and does a 32b sysret if it is FLAT_USER_CS32.
However, this is different from __USER32_CS, so it fails to return
properly if we use the normal Linux segment.
So avoid the whole mess by dropping VCGF_in_syscall and simply use
plain iret to return to usermode.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Jan Beulich <jbeulich@novell.com>
Cc: Stable Kernel <stable@kernel.org>
printk timestamping uses sched_clock, which in turn relies on runstate
info under Xen. So make sure we set it up before any printks can
be called.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>
The commit "xen: re-register runstate area earlier on resume" caused us
to never try and setup the runstate area for secondary CPUs. Ensure that
we do this...
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>
Otherwise the timer is disabled by dpm_suspend_noirq() which in turn prevents
correct operation of stop_machine on multi-processor systems and breaks
suspend.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>
pvops kernels >= 2.6.30 can currently only be saved and restored once. The
second attempt to save results in:
ERROR Internal error: Frame# in pfn-to-mfn frame list is not in pseudophys
ERROR Internal error: entry 0: p2m_frame_list[0] is 0xf2c2c2c2, max 0x120000
ERROR Internal error: Failed to map/save the p2m frame list
I finally narrowed it down to:
commit cdaead6b4e
Author: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Date: Fri Feb 27 15:34:59 2009 -0800
xen: split construction of p2m mfn tables from registration
Build the p2m_mfn_list_list early with the rest of the p2m table, but
register it later when the real shared_info structure is in place.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
The unforeseen side-effect of this change was to cause the mfn list list to not
be rebuilt on resume. Prior to this change it would have been rebuilt via
xen_post_suspend() -> xen_setup_shared_info() -> xen_setup_mfn_list_list().
Fix by explicitly calling xen_build_mfn_list_list() from xen_post_suspend().
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>
Even if have_vcpu_info_placement is not set, we still need to set up
the runstate area on each resumed vcpu.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>
This is necessary to ensure the runstate area is available to
xen_sched_clock before any calls to printk which will require it in
order to provide a timestamp.
I chose to pull the xen_setup_runstate_info out of xen_time_init into
the caller in order to maintain parity with calling
xen_setup_runstate_info separately from calling xen_time_resume.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>
The 32- and 64-bit code used very different mechanisms for enabling
NX, but even the 32-bit code was enabling NX in head_32.S if it is
available. Furthermore, we had a bewildering collection of tests for
the available of NX.
This patch:
a) merges the 32-bit set_nx() and the 64-bit check_efer() function
into a single x86_configure_nx() function. EFER control is left
to the head code.
b) eliminates the nx_enabled variable entirely. Things that need to
test for NX enablement can verify __supported_pte_mask directly,
and cpu_has_nx gives the supported status of NX.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Vegard Nossum <vegardno@ifi.uio.no>
Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Chris Wright <chrisw@sous-sol.org>
LKML-Reference: <1258154897-6770-5-git-send-email-hpa@zytor.com>
Acked-by: Kees Cook <kees.cook@canonical.com>
Move xen_domain and related tests out of asm-x86 to xen/xen.h so they
can be included whenever they are necessary.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
A Xen guest never needs to know about extended topology, and knowing
would just confuse it.
This patch just zeros ebx in leaf 0xb which indicates no topology info,
preventing a crash under Xen on cpus which support this leaf.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>
Now that the return from alloc_percpu is compatible with the address
of per-cpu vars, it makes sense to hand around the address of per-cpu
variables. To make this sane, we remove the per_cpu__ prefix we used
created to stop people accidentally using these vars directly.
Now we have sparse, we can use that (next patch).
tj: * Updated to convert stuff which were missed by or added after the
original patch.
* Kill per_cpu_var() macro.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
This patch updates percpu related symbols in xen such that percpu
symbols are unique and don't clash with local symbols. This serves
two purposes of decreasing the possibility of global percpu symbol
collision and allowing dropping per_cpu__ prefix from percpu symbols.
* arch/x86/xen/smp.c, arch/x86/xen/time.c, arch/ia64/xen/irq_xen.c:
add xen_ prefix to percpu variables
* arch/ia64/xen/time.c: add xen_ prefix to percpu variables, drop
processed_ prefix and make them static
Partly based on Rusty Russell's "alloc_percpu: rename percpu vars
which cause name clashes" patch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Chris Wright <chrisw@sous-sol.org>
xen_setup_stackprotector() ends up trying to set page protections,
so we need to have vm_mmu_ops set up before trying to do so.
Failing to do so causes an early boot crash.
[ Impact: Fix early crash under Xen. ]
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: Remove redundant non-NUMA topology functions
x86: early_printk: Protect against using the same device twice
x86: Reduce verbosity of "PAT enabled" kernel message
x86: Reduce verbosity of "TSC is reliable" message
x86: mce: Use safer ways to access MCE registers
x86: mce, inject: Use real inject-msg in raise_local
x86: mce: Fix thermal throttling message storm
x86: mce: Clean up thermal throttling state tracking code
x86: split NX setup into separate file to limit unstack-protected code
xen: check EFER for NX before setting up GDT mapping
x86: Cleanup linker script using new linker script macros.
x86: Use section .data.page_aligned for the idt_table.
x86: convert to use __HEAD and HEAD_TEXT macros.
x86: convert compressed loader to use __HEAD and HEAD_TEXT macros.
x86: fix fragile computation of vsyscall address
Makes code futureproof against the impending change to mm->cpu_vm_mask (to be a pointer).
It's also a chance to use the new cpumask_ ops which take a pointer
(the older ones are deprecated, but there's no hurry for arch code).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
x86-64 assumes NX is available by default, so we need to
explicitly check for it before using NX. Some first-generation
Intel x86-64 processors didn't support NX, and even recent systems
allow it to be disabled in BIOS.
[ Impact: prevent Xen crash on NX-less 64-bit machines ]
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>
* 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (38 commits)
x86: Move get/set_wallclock to x86_platform_ops
x86: platform: Fix section annotations
x86: apic namespace cleanup
x86: Distangle ioapic and i8259
x86: Add Moorestown early detection
x86: Add hardware_subarch ID for Moorestown
x86: Add early platform detection
x86: Move tsc_init to late_time_init
x86: Move tsc_calibration to x86_init_ops
x86: Replace the now identical time_32/64.c by time.c
x86: time_32/64.c unify profile_pc
x86: Move calibrate_cpu to tsc.c
x86: Make timer setup and global variables the same in time_32/64.c
x86: Remove mca bus ifdef from timer interrupt
x86: Simplify timer_ack magic in time_32.c
x86: Prepare unification of time_32/64.c
x86: Remove do_timer hook
x86: Add timer_init to x86_init_ops
x86: Move percpu clockevents setup to x86_init_ops
x86: Move xen_post_allocator_init into xen_pagetable_setup_done
...
Fix up conflicts in arch/x86/include/asm/io_apic.h
get/set_wallclock() have already a set of platform dependent
implementations (default, EFI, paravirt). MRST will add another
variant.
Moving them to platform ops simplifies the existing code and minimizes
the effort to integrate new variants.
Signed-off-by: Feng Tang <feng.tang@intel.com>
LKML-Reference: <new-submission>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* 'x86-xen-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: split __phys_addr out into separate file
xen: use stronger barrier after unlocking lock
xen: only enable interrupts while actually blocking for spinlock
xen: make -fstack-protector work under Xen
* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (22 commits)
x86: Fix code patching for paravirt-alternatives on 486
x86, msr: change msr-reg.o to obj-y, and export its symbols
x86: Use hard_smp_processor_id() to get apic id for AMD K8 cpus
x86, sched: Workaround broken sched domain creation for AMD Magny-Cours
x86, mcheck: Use correct cpumask for shared bank4
x86, cacheinfo: Fixup L3 cache information for AMD multi-node processors
x86: Fix CPU llc_shared_map information for AMD Magny-Cours
x86, msr: Fix msr-reg.S compilation with gas 2.16.1, on 32-bit too
x86: Move kernel_fpu_using to irq_fpu_usable in asm/i387.h
x86, msr: fix msr-reg.S compilation with gas 2.16.1
x86, msr: Export the register-setting MSR functions via /dev/*/msr
x86, msr: Create _on_cpu helpers for {rw,wr}msr_safe_regs()
x86, msr: Have the _safe MSR functions return -EIO, not -EFAULT
x86, msr: CFI annotations, cleanups for msr-reg.S
x86, asm: Make _ASM_EXTABLE() usable from assembly code
x86, asm: Add 32-bit versions of the combined CFI macros
x86, AMD: Disable wrongly set X86_FEATURE_LAHF_LM CPUID bit
x86, msr: Rewrite AMD rd/wrmsr variants
x86, msr: Add rd/wrmsr interfaces with preset registers
x86: add specific support for Intel Atom architecture
...
We need to have a stronger barrier between releasing the lock and
checking for any waiting spinners. A compiler barrier is not sufficient
because the CPU's ordering rules do not prevent the read xl->spinners
from happening before the unlock assignment, as they are different
memory locations.
We need to have an explicit barrier to enforce the write-read ordering
to different memory locations.
Because of it, I can't bring up > 4 HVM guests on one SMP machine.
[ Code and commit comments expanded -J ]
[ Impact: avoid deadlock when using Xen PV spinlocks ]
Signed-off-by: Yang Xiaowei <xiaowei.yang@intel.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Where possible we enable interrupts while waiting for a spinlock to
become free, in order to reduce big latency spikes in interrupt handling.
However, at present if we manage to pick up the spinlock just before
blocking, we'll end up holding the lock with interrupts enabled for a
while. This will cause a deadlock if we recieve an interrupt in that
window, and the interrupt handler tries to take the lock too.
Solve this by shrinking the interrupt-enabled region to just around the
blocking call.
[ Impact: avoid race/deadlock when using Xen PV spinlocks ]
Reported-by: "Yang, Xiaowei" <xiaowei.yang@intel.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
-fstack-protector uses a special per-cpu "stack canary" value.
gcc generates special code in each function to test the canary to make
sure that the function's stack hasn't been overrun.
On x86-64, this is simply an offset of %gs, which is the usual per-cpu
base segment register, so setting it up simply requires loading %gs's
base as normal.
On i386, the stack protector segment is %gs (rather than the usual kernel
percpu %fs segment register). This requires setting up the full kernel
GDT and then loading %gs accordingly. We also need to make sure %gs is
initialized when bringing up secondary cpus too.
To keep things consistent, we do the full GDT/segment register setup on
both architectures.
Because we need to avoid -fstack-protected code before setting up the GDT
and because there's no way to disable it on a per-function basis, several
files need to have stack-protector inhibited.
[ Impact: allow Xen booting with stack-protector enabled ]
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
For some reason, the _safe MSR functions returned -EFAULT, not -EIO.
However, the only user which cares about the return code as anything
other than a boolean is the MSR driver, which wants -EIO. Change it
to -EIO across the board.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
TSC calibration is modified by the vmware hypervisor and paravirt by
separate means. Moorestown wants to add its own calibration routine as
well. So make calibrate_tsc a proper x86_init_ops function and
override it by paravirt or by the early setup of the vmware
hypervisor.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The timer init code is convoluted with several quirks and the paravirt
timer chooser. Figuring out which code path is actually taken is not
for the faint hearted.
Move the numaq TSC quirk to tsc_pre_init x86_init_ops function and
replace the paravirt time chooser and the remaining x86 quirk with a
simple x86_init_ops function.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
paravirt overrides the setup of the default apic timers as per cpu
timers. Moorestown needs to override that as well.
Move it to x86_init_ops setup and create a separate x86_cpuinit struct
which holds the function for the secondary evtl. hotplugabble CPUs.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
We really do not need two paravirt/x86_init_ops functions which are
called in two consecutive source lines. Move the only user of
post_allocator_init into the already existing pagetable_setup_done
function.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Replace another obscure paravirt magic and move it to
x86_init_ops. Such a hook is also useful for embedded and special
hardware.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
ARCH_SETUP is a horrible leftover from the old arch/i386 mach support
code. It still has a lonely user in xen. Move it to x86_init_ops.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
irq_init is overridden by x86_quirks and by paravirts. Unify the whole
mess and make it an unconditional x86_init_ops function which defaults
to the standard function and can be overridden by the early platform
code.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
memory_setup is overridden by x86_quirks and by paravirts with weak
functions and quirks. Unify the whole mess and make it an
unconditional x86_init_ops function which defaults to the standard
function and can be overridden by the early platform code.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Initialize cx before calling xen_cpuid(), in order to suppress the
"may be used uninitialized in this function" warning.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Xen always runs on CPUs which properly support WP enforcement in
privileged mode, so there's no need to test for it.
This also works around a crash reported by Arnd Hannemann, though I
think its just a band-aid for that case.
Reported-by: Arnd Hannemann <hannemann@nets.rwth-aachen.de>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Make sure the stack-protector segment registers are properly set up
before calling any functions which may have stack-protection compiled
into them.
[ Impact: prevent Xen early-boot crash when stack-protector is enabled ]
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
* 'x86-xen-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (42 commits)
xen: cache cr0 value to avoid trap'n'emulate for read_cr0
xen/x86-64: clean up warnings about IST-using traps
xen/x86-64: fix breakpoints and hardware watchpoints
xen: reserve Xen start_info rather than e820 reserving
xen: add FIX_TEXT_POKE to fixmap
lguest: update lazy mmu changes to match lguest's use of kvm hypercalls
xen: honour VCPU availability on boot
xen: add "capabilities" file
xen: drop kexec bits from /sys/hypervisor since kexec isn't implemented yet
xen/sys/hypervisor: change writable_pt to features
xen: add /sys/hypervisor support
xen/xenbus: export xenbus_dev_changed
xen: use device model for suspending xenbus devices
xen: remove suspend_cancel hook
xen/dev-evtchn: clean up locking in evtchn
xen: export ioctl headers to userspace
xen: add /dev/xen/evtchn driver
xen: add irq_from_evtchn
xen: clean up gate trap/interrupt constants
xen: set _PAGE_NX in __supported_pte_mask before pagetable construction
...
Xiaohui Xin and some other folks at Intel have been looking into what's
behind the performance hit of paravirt_ops when running native.
It appears that the hit is entirely due to the paravirtualized
spinlocks introduced by:
| commit 8efcbab674
| Date: Mon Jul 7 12:07:51 2008 -0700
|
| paravirt: introduce a "lock-byte" spinlock implementation
The extra call/return in the spinlock path is somehow
causing an increase in the cycles/instruction of somewhere around 2-7%
(seems to vary quite a lot from test to test). The working theory is
that the CPU's pipeline is getting upset about the
call->call->locked-op->return->return, and seems to be failing to
speculate (though I haven't seen anything definitive about the precise
reasons). This doesn't entirely make sense, because the performance
hit is also visible on unlock and other operations which don't involve
locked instructions. But spinlock operations clearly swamp all the
other pvops operations, even though I can't imagine that they're
nearly as common (there's only a .05% increase in instructions
executed).
If I disable just the pv-spinlock calls, my tests show that pvops is
identical to non-pvops performance on native (my measurements show that
it is actually about .1% faster, but Xiaohui shows a .05% slowdown).
Summary of results, averaging 10 runs of the "mmperf" test, using a
no-pvops build as baseline:
nopv Pv-nospin Pv-spin
CPU cycles 100.00% 99.89% 102.18%
instructions 100.00% 100.10% 100.15%
CPI 100.00% 99.79% 102.03%
cache ref 100.00% 100.84% 100.28%
cache miss 100.00% 90.47% 88.56%
cache miss rate 100.00% 89.72% 88.31%
branches 100.00% 99.93% 100.04%
branch miss 100.00% 103.66% 107.72%
branch miss rt 100.00% 103.73% 107.67%
wallclock 100.00% 99.90% 102.20%
The clear effect here is that the 2% increase in CPI is
directly reflected in the final wallclock time.
(The other interesting effect is that the more ops are
out of line calls via pvops, the lower the cache access
and miss rates. Not too surprising, but it suggests that
the non-pvops kernel is over-inlined. On the flipside,
the branch misses go up correspondingly...)
So, what's the fix?
Paravirt patching turns all the pvops calls into direct calls, so
_spin_lock etc do end up having direct calls. For example, the compiler
generated code for paravirtualized _spin_lock is:
<_spin_lock+0>: mov %gs:0xb4c8,%rax
<_spin_lock+9>: incl 0xffffffffffffe044(%rax)
<_spin_lock+15>: callq *0xffffffff805a5b30
<_spin_lock+22>: retq
The indirect call will get patched to:
<_spin_lock+0>: mov %gs:0xb4c8,%rax
<_spin_lock+9>: incl 0xffffffffffffe044(%rax)
<_spin_lock+15>: callq <__ticket_spin_lock>
<_spin_lock+20>: nop; nop /* or whatever 2-byte nop */
<_spin_lock+22>: retq
One possibility is to inline _spin_lock, etc, when building an
optimised kernel (ie, when there's no spinlock/preempt
instrumentation/debugging enabled). That will remove the outer
call/return pair, returning the instruction stream to a single
call/return, which will presumably execute the same as the non-pvops
case. The downsides arel 1) it will replicate the
preempt_disable/enable code at eack lock/unlock callsite; this code is
fairly small, but not nothing; and 2) the spinlock definitions are
already a very heavily tangled mass of #ifdefs and other preprocessor
magic, and making any changes will be non-trivial.
The other obvious answer is to disable pv-spinlocks. Making them a
separate config option is fairly easy, and it would be trivial to
enable them only when Xen is enabled (as the only non-default user).
But it doesn't really address the common case of a distro build which
is going to have Xen support enabled, and leaves the open question of
whether the native performance cost of pv-spinlocks is worth the
performance improvement on a loaded Xen system (10% saving of overall
system CPU when guests block rather than spin). Still it is a
reasonable short-term workaround.
[ Impact: fix pvops performance regression when running native ]
Analysed-by: "Xin Xiaohui" <xiaohui.xin@intel.com>
Analysed-by: "Li Xin" <xin.li@intel.com>
Analysed-by: "Nakajima Jun" <jun.nakajima@intel.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Xen-devel <xen-devel@lists.xensource.com>
LKML-Reference: <4A0B62F7.5030802@goop.org>
[ fixed the help text ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
mmu.c needs to #include module.h to prevent these warnings:
arch/x86/xen/mmu.c:239: warning: data definition has no type or storage class
arch/x86/xen/mmu.c:239: warning: type defaults to 'int' in declaration of 'EXPORT_SYMBOL_GPL'
arch/x86/xen/mmu.c:239: warning: parameter names (without types) in function declaration
[ Impact: cleanup ]
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
stts() is implemented in terms of read_cr0/write_cr0 to update the
state of the TS bit. This happens during context switch, and so
is fairly performance critical. Rather than falling back to
a trap-and-emulate native read_cr0, implement our own by caching
the last-written value from write_cr0 (the TS bit is the only one
we really care about).
Impact: optimise Xen context switches
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Ignore known IST-using traps. Aside from the debugger traps, they're
low-level faults which Xen will handle for us, so the kernel needn't
worry about them. Keep warning in case unknown trap starts using IST.
Impact: suppress spurious warnings
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Native x86-64 uses the IST mechanism to run int3 and debug traps on
an alternative stack. Xen does not do this, and so the frames were
being misinterpreted by the ptrace code. This change special-cases
these two exceptions by using Xen variants which run on the normal
kernel stack properly.
Impact: avoid crash or bad data when IST trap is invoked under Xen
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Use reserve_early rather than e820 reservations for Xen start info and mfn->pfn
table, so that the memory use is a bit more self-documenting.
[ Impact: cleanup ]
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Xen-devel <xen-devel@lists.xensource.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <4A032EF1.6070708@goop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Conflicts:
arch/frv/include/asm/pgtable.h
arch/x86/include/asm/required-features.h
arch/x86/xen/mmu.c
Merge reason: x86/xen was on a .29 base still, move it to a fresher
branch and pick up Xen fixes as well, plus resolve
conflicts
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The Xen pagetables are no longer implicitly reserved as part of the other
i386_start_kernel reservations, so make sure we explicitly reserve them.
This prevents them from being released into the general kernel free page
pool and reused.
[ Impact: fix Xen guest crash ]
Also-Bisected-by: Bryan Donlan <bdonlan@gmail.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Xen-devel <xen-devel@lists.xensource.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <4A032EEC.30509@goop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Pass clocksource pointer to the read() callback for clocksources. This
allows us to share the callback between multiple instances.
[hugh@veritas.com: fix powerpc build of clocksource pass clocksource mods]
[akpm@linux-foundation.org: cleanup]
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Acked-by: John Stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-rc1/xen/core' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen:
xen: add FIX_TEXT_POKE to fixmap
xen: honour VCPU availability on boot
xen: clean up gate trap/interrupt constants
xen: set _PAGE_NX in __supported_pte_mask before pagetable construction
xen: resume interrupts before system devices.
xen/mmu: weaken flush_tlb_other test
xen/mmu: some early pagetable cleanups
Xen: Add virt_to_pfn helper function
x86-64: remove PGE from must-have feature list
xen: mask XSAVE from cpuid
NULL noise: arch/x86/xen/smp.c
xen: remove xen_load_gdt debug
xen: make xen_load_gdt simpler
xen: clean up xen_load_gdt
xen: split construction of p2m mfn tables from registration
xen: separate p2m allocation from setting
xen: disable preempt for leave_lazy_mmu
Use phys_addr_t for receiving a physical address argument instead of
unsigned long. This allows fixmap to handle pages higher than 4GB on
x86-32.
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
FIX_TEXT_POKE[01] are used to map kernel addresses, so they're mapping
pfns, not mfns.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
FIX_TEXT_POKE[01] are used to map kernel addresses, so they're mapping
pfns, not mfns.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Some 64-bit machines don't support the NX flag in ptes.
Check for NX before constructing the kernel pagetables.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Impact: fixes crashing bug
There's no particular problem with getting an empty cpu mask,
so just shortcut-return if we get one.
Avoids crash reported by Christophe Saout <christophe@saout.de>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
1. make sure early-allocated ptes are pinned, so they can be later
unpinned
2. don't pin pmd+pud, just make them RO
3. scatter some __inits around
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Xen leaves XSAVE set in cpuid, but doesn't allow cr4.OSXSAVE
to be set. This confuses the kernel and it ends up crashing on
an xsetbv instruction.
At boot time, try to set cr4.OSXSAVE, and mask XSAVE out of
cpuid it we can't. This will produce a spurious error from Xen,
but allows us to support XSAVE if/when Xen does.
This also factors out the cpuid mask decisions to boot time.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Fix this sparse warnings:
arch/x86/xen/smp.c:316:52: warning: Using plain integer as NULL pointer
arch/x86/xen/smp.c:421:60: warning: Using plain integer as NULL pointer
Signed-off-by: Hannes Eder <hannes@hanneseder.net>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Remove use of multicall machinery which is unused (gdt loading
is never performance critical). This removes the implicit use
of percpu variables, which simplifies understanding how
the percpu code's use of load_gdt interacts with this code.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Build the p2m_mfn_list_list early with the rest of the p2m table, but
register it later when the real shared_info structure is in place.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
When doing very early p2m setting, we need to separate setting
from allocation, so split things up accordingly.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
xen_mc_flush() requires preemption to be disabled for its own sanity,
so disable it while we're flushing.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
* commit 'origin/master': (4825 commits)
Fix build errors due to CONFIG_BRANCH_TRACER=y
parport: Use the PCI IRQ if offered
tty: jsm cleanups
Adjust path to gpio headers
KGDB_SERIAL_CONSOLE check for module
Change KCONFIG name
tty: Blackin CTS/RTS
Change hardware flow control from poll to interrupt driven
Add support for the MAX3100 SPI UART.
lanana: assign a device name and numbering for MAX3100
serqt: initial clean up pass for tty side
tty: Use the generic RS485 ioctl on CRIS
tty: Correct inline types for tty_driver_kref_get()
splice: fix deadlock in splicing to file
nilfs2: support nanosecond timestamp
nilfs2: introduce secondary super block
nilfs2: simplify handling of active state of segments
nilfs2: mark minor flag for checkpoint created by internal operation
nilfs2: clean up sketch file
nilfs2: super block operations fix endian bug
...
Conflicts:
arch/x86/include/asm/thread_info.h
arch/x86/lguest/boot.c
drivers/xen/manage.c
Some 64-bit machines don't support the NX flag in ptes.
Check for NX before constructing the kernel pagetables.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Impact: fixes crashing bug
There's no particular problem with getting an empty cpu mask,
so just shortcut-return if we get one.
Avoids crash reported by Christophe Saout <christophe@saout.de>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
1. make sure early-allocated ptes are pinned, so they can be later
unpinned
2. don't pin pmd+pud, just make them RO
3. scatter some __inits around
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Xen leaves XSAVE set in cpuid, but doesn't allow cr4.OSXSAVE
to be set. This confuses the kernel and it ends up crashing on
an xsetbv instruction.
At boot time, try to set cr4.OSXSAVE, and mask XSAVE out of
cpuid it we can't. This will produce a spurious error from Xen,
but allows us to support XSAVE if/when Xen does.
This also factors out the cpuid mask decisions to boot time.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Fix this sparse warnings:
arch/x86/xen/smp.c:316:52: warning: Using plain integer as NULL pointer
arch/x86/xen/smp.c:421:60: warning: Using plain integer as NULL pointer
Signed-off-by: Hannes Eder <hannes@hanneseder.net>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Remove use of multicall machinery which is unused (gdt loading
is never performance critical). This removes the implicit use
of percpu variables, which simplifies understanding how
the percpu code's use of load_gdt interacts with this code.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Build the p2m_mfn_list_list early with the rest of the p2m table, but
register it later when the real shared_info structure is in place.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
When doing very early p2m setting, we need to separate setting
from allocation, so split things up accordingly.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
xen_mc_flush() requires preemption to be disabled for its own sanity,
so disable it while we're flushing.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Impact: remove obsolete checks, simplification
Lift restrictions on preemption with lazy mmu mode, as it is now allowed.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Impact: fix lazy context switch API
Pass the previous and next tasks into the context switch start
end calls, so that the called functions can properly access the
task state (esp in end_context_switch, in which the next task
is not yet completely current).
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Impact: allow preemption during lazy mmu updates
If we're in lazy mmu mode when context switching, leave
lazy mmu mode, but remember the task's state in
TIF_LAZY_MMU_UPDATES. When we resume the task, check this
flag and re-enter lazy mmu mode if its set.
This sets things up for allowing lazy mmu mode while preemptible,
though that won't actually be active until the next change.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Impact: simplification, prepare for later changes
Make lazy cpu mode more specific to context switching, so that
it makes sense to do more context-switch specific things in
the callbacks.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Impact: new interface
Add a brk()-like allocator which effectively extends the bss in order
to allow very early code to do dynamic allocations. This is better than
using statically allocated arrays for data in subsystems which may never
get used.
The space for brk allocations is in the bss ELF segment, so that the
space is mapped properly by the code which maps the kernel, and so
that bootloaders keep the space free rather than putting a ramdisk or
something into it.
The bss itself, delimited by __bss_stop, ends before the brk area
(__brk_base to __brk_limit). The kernel text, data and bss is reserved
up to __bss_stop.
Any brk-allocated data is reserved separately just before the kernel
pagetable is built, as that code allocates from unreserved spaces
in the e820 map, potentially allocating from any unused brk memory.
Ultimately any unused memory in the brk area is used in the general
kernel memory pool.
Initially the brk space is set to 1MB, which is probably much larger
than any user needs (the largest current user is i386 head_32.S's code
to build the pagetables to map the kernel, which can get fairly large
with a big kernel image and no PSE support). So long as the system
has sufficient memory for the bootloader to reserve the kernel+1MB brk,
there are no bad effects resulting from an over-large brk.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
The virtually mapped percpu space causes us two problems:
- for hypercalls which take an mfn, we need to do a full pagetable
walk to convert the percpu va into an mfn, and
- when a hypercall requires a page to be mapped RO via all its aliases,
we need to make sure its RO in both the percpu mapping and in the
linear mapping
This primarily affects the gdt and the vcpu info structure.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Xen-devel <xen-devel@lists.xensource.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Tejun Heo <htejun@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This avoids a lockdep warning from:
if (DEBUG_LOCKS_WARN_ON(unlikely(!early_boot_irqs_enabled)))
return;
in trace_hardirqs_on_caller();
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Cc: Xen-devel <xen-devel@lists.xensource.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: remove unused/broken code
The Voyager subarch last built successfully on the v2.6.26 kernel
and has been stale since then and does not build on the v2.6.27,
v2.6.28 and v2.6.29-rc5 kernels.
No actual users beyond the maintainer reported this breakage.
Patches were sent and most of the fixes were accepted but the
discussion around how to do a few remaining issues cleanly
fizzled out with no resolution and the code remained broken.
In the v2.6.30 x86 tree development cycle 32-bit subarch support
has been reworked and removed - and the Voyager code, beyond the
build problems already known, needs serious and significant
changes and probably a rewrite to support it.
CONFIG_X86_VOYAGER has been marked BROKEN then. The maintainer has
been notified but no patches have been sent so far to fix it.
While all other subarchs have been converted to the new scheme,
voyager is still broken. We'd prefer to receive patches which
clean up the current situation in a constructive way, but even in
case of removal there is no obstacle to add that support back
after the issues have been sorted out in a mutually acceptable
fashion.
So remove this inactive code for now.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
make it simpler, don't need have one extra struct.
v2: fix the sgi_uv build
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
We can't call the callbacks after enabling interrupts, as we may get a
nested multicall call, which would cause a great deal of havok.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
If one of the components of a multicall fails, WARN rather than BUG,
to help with debugging.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Store the caller for each multicall so we can report it on failure.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
In general, the only definitions that assembly files can use
are in _types.S headers (where available), so convert them.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
The commit
commit 4595f9620c
Author: Rusty Russell <rusty@rustcorp.com.au>
Date: Sat Jan 10 21:58:09 2009 -0800
x86: change flush_tlb_others to take a const struct cpumask
causes xen_flush_tlb_others to allocate a multicall and then issue it
without initializing it in the case where the cpumask is empty,
leading to:
[ 8.354898] 1 multicall(s) failed: cpu 1
[ 8.354921] Pid: 2213, comm: bootclean Not tainted 2.6.29-rc3-x86_32p-xenU-tip #135
[ 8.354937] Call Trace:
[ 8.354955] [<c01036e3>] xen_mc_flush+0x133/0x1b0
[ 8.354971] [<c0105d2a>] ? xen_force_evtchn_callback+0x1a/0x30
[ 8.354988] [<c0105a60>] xen_flush_tlb_others+0xb0/0xd0
[ 8.355003] [<c0126643>] flush_tlb_page+0x53/0xa0
[ 8.355018] [<c0176a80>] do_wp_page+0x2a0/0x7c0
[ 8.355034] [<c0238f0a>] ? notify_remote_via_irq+0x3a/0x70
[ 8.355049] [<c0178950>] handle_mm_fault+0x7b0/0xa50
[ 8.355065] [<c0131a3e>] ? wake_up_new_task+0x8e/0xb0
[ 8.355079] [<c01337b5>] ? do_fork+0xe5/0x320
[ 8.355095] [<c0121919>] do_page_fault+0xe9/0x240
[ 8.355109] [<c0121830>] ? do_page_fault+0x0/0x240
[ 8.355125] [<c032457a>] error_code+0x72/0x78
[ 8.355139] call 1/1: op=2863311530 arg=[aaaaaaaa] result=-38 xen_flush_tlb_others+0x41/0xd0
Since empty cpumasks are rare and undoing an xen_mc_entry() is tricky
just issue such requests normally.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: pt_regs changed, lazy gs handling made optional, add slight
overhead to SAVE_ALL, simplifies error_code path a bit
On x86_32, %gs hasn't been used by kernel and handled lazily. pt_regs
doesn't have place for it and gs is saved/loaded only when necessary.
In preparation for stack protector support, this patch makes lazy %gs
handling optional by doing the followings.
* Add CONFIG_X86_32_LAZY_GS and place for gs in pt_regs.
* Save and restore %gs along with other registers in entry_32.S unless
LAZY_GS. Note that this unfortunately adds "pushl $0" on SAVE_ALL
even when LAZY_GS. However, it adds no overhead to common exit path
and simplifies entry path with error code.
* Define different user_gs accessors depending on LAZY_GS and add
lazy_save_gs() and lazy_load_gs() which are noop if !LAZY_GS. The
lazy_*_gs() ops are used to save, load and clear %gs lazily.
* Define ELF_CORE_COPY_KERNEL_REGS() which always read %gs directly.
xen and lguest changes need to be verified.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Rather than overloading vectors for event channels, take full
responsibility for mapping an event channel to irq directly. With
this patch Xen has its own irq allocator.
When the kernel gets an event channel upcall, it maps the event
channel number to an irq and injects it into the normal interrupt
path.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Make the following style cleanups:
* drop unnecessary //#include from xen-asm_32.S
* compulsive adding of space after comma
* reformat multiline comments
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Enable the use of the direct vcpu-access operations on 64-bit.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Now that x86-64 has directly accessible percpu variables, it can also
implement the direct versions of these operations, which operate on a
vcpu_info structure directly embedded in the percpu area.
In fact, the 64-bit versions are more or less identical, and so can be
shared. The only two differences are:
1. xen_restore_fl_direct takes its argument in eax on 32-bit, and rdi on 64-bit.
Unfortunately it isn't possible to directly refer to the 2nd lsb of rdi directly
(as you can with %ah), so the code isn't quite as dense.
2. check_events needs to variants to save different registers.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
We need to access percpu data fairly early, so set up the percpu
registers as soon as possible. We only need to load the appropriate
segment register. We already have a GDT, but its hard to change it
early because we need to manipulate the pagetable to do so, and that
hasn't been set up yet.
Also, set the kernel stack when bringing up secondary CPUs. If we
don't they all end up sharing the same stack...
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Moving the mmu code from enlighten.c to mmu.c inadvertently broke the
32-bit build. Fix it.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Impact: Fix race condition
xen_mc_batch has a small preempt race where it takes the address of a
percpu variable immediately before disabling interrupts, thereby
leaving a small window in which we may migrate to another cpu and save
the flags in the wrong percpu variable. Disable interrupts before
saving the old flags in a percpu.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Impact: fix xen booting
We need to access percpu data fairly early, so set up the percpu
registers as soon as possible. We only need to load the appropriate
segment register. We already have a GDT, but its hard to change it
early because we need to manipulate the pagetable to do so, and that
hasn't been set up yet.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Impact: Optimization
In the native case, pte_val, make_pte, etc are all just identity
functions, so there's no need to clobber a lot of registers over them.
(This changes the 32-bit callee-save calling convention to return both
EAX and EDX so functions can return 64-bit values.)
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Impact: Optimization
One of the problems with inserting a pile of C calls where previously
there were none is that the register pressure is greatly increased.
The C calling convention says that the caller must expect a certain
set of registers may be trashed by the callee, and that the callee can
use those registers without restriction. This includes the function
argument registers, and several others.
This patch seeks to alleviate this pressure by introducing wrapper
thunks that will do the register saving/restoring, so that the
callsite doesn't need to worry about it, but the callee function can
be conventional compiler-generated code. In many cases (particularly
performance-sensitive cases) the callee will be in assembler anyway,
and need not use the compiler's calling convention.
Standard calling convention is:
arguments return scratch
x86-32 eax edx ecx eax ?
x86-64 rdi rsi rdx rcx rax r8 r9 r10 r11
The thunk preserves all argument and scratch registers. The return
register is not preserved, and is available as a scratch register for
unwrapped callee code (and of course the return value).
Wrapped function pointers are themselves wrapped in a struct
paravirt_callee_save structure, in order to get some warning from the
compiler when functions with mismatched calling conventions are used.
The most common paravirt ops, both statically and dynamically, are
interrupt enable/disable/save/restore, so handle them first. This is
particularly easy since their calls are handled specially anyway.
XXX Deal with VMI. What's their calling convention?
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Impact: Cleanup
Move remaining mmu-related stuff into mmu.c.
A general cleanup, and lay the groundwork for later patches.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
