15 May, 2008
4 commits
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Surround all the code withing show_interrupts() with
get/put_online_cpus() to prevent strange results wrt cpu hotplug.Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky -
Both smp_call_function() and __smp_call_function_map() access
cpu_online_map. Both functions run with preemption disabled which
protects for cpus going offline. However new cpus can be added and
therefore the cpu_online_map can change unexpectedly.
So use the call_lock to protect against changes to the cpu_online_map
in start_secondary() and all smp_call_* functions.Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky -
We should use const char * for passing the name of the debug feature
around since it will not be changed.Signed-off-by: Cornelia Huck
Signed-off-by: Martin Schwidefsky -
Let's just use the generic vmmemmap_alloc_block() function which
always returns initialized memory.Cc: Gerald Schaefer
Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky
07 May, 2008
4 commits
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Use the existing arch_alloc_page/arch_free_page callbacks to do
the guest page state transitions between stable and unused.Acked-by: Rik van Riel
Signed-off-by: Martin Schwidefsky -
This removes redundant arch code for generic ptrace requests
already handled by ptrace_request and compat_ptrace_request.
It simplifies things to just have the standard entry points,
and use the generic compat_sys_ptrace.Signed-off-by: Roland McGrath
Signed-off-by: Martin Schwidefsky -
From: Martin Schwidefsky
This patch fixes a bug with cpu bound guest on kvm-s390. Sometimes it
was impossible to deliver a signal to a spinning guest. We used
preemption as a circumvention. The preemption notifiers called
vcpu_load, which checked for pending signals and triggered a host
intercept. But even with preemption, a sigkill was not delivered
immediately.This patch changes the low level host interrupt handler to check for the
SIE instruction, if TIF_WORK is set. In that case we change the
instruction pointer of the return PSW to rerun the vcpu_run loop. The kvm
code sees an intercept reason 0 if that happens. This patch adds accounting
for these types of intercept as well.The advantages:
- works with and without preemption
- signals are delivered immediately
- much better host latencies without preemptionAcked-by: Carsten Otte
Signed-off-by: Christian Borntraeger
Signed-off-by: Martin Schwidefsky -
On return from syscall or interrupt, we have to check if we return to
userspace (likely) and if there is work todo (less likely) to decide
if we handle the work. We can optimize this check: we first check for
the less likely work case and then check for userspace.This patch is also a preparation for an additional patch, that fixes a bug
in KVM dealing with cpu bound guests.Signed-off-by: Martin Schwidefsky
04 May, 2008
1 commit
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This replaces the duplicated arch-specific versions of "sys_pipe()" with
one unified implementation. This removes almost 250 lines of duplicated
code.It's marked __weak, so that *if* an architecture wants to override the
default implementation it can do so by simply having its own replacement
version, since many architectures use alternate calling conventions for
the 'pipe()' system call for legacy reasons (ie traditional UNIX
implementations often return the two file descriptors in registers)I still haven't changed the cris version even though Linus says the BKL
isn't needed. The arch maintainer can easily do it if there are really
no obstacles.Signed-off-by: Ulrich Drepper
Signed-off-by: Linus Torvalds
30 Apr, 2008
17 commits
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* 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6:
[S390] Update default configuration.
[S390] use generic sys_ptrace
[S390] Remove self ptrace IEEE_IP hack.
[S390] Convert to SPARSEMEM & SPARSEMEM_VMEMMAP
[S390] System z large page support.
[S390] Convert machine feature detection code to C.
[S390] vmemmap: use clear_table to initialise page tables.
[S390] Move stfl to system.h and delete duplicated version.
[S390] uaccess_mvcos: #ifdef config dependent code.
[S390] cpu topology: Fix possible deadlock.
[S390] Add topology_core_siblings to topology.h
[S390] cio: Make isc handling more robust.
[S390] remove -traditional
[S390] Automatically detect added cpus.
[S390] smp: Fix locking order.
[S390] Add missing ifndef/define to include/asm-s390/sysinfo.h.
[S390] Move show_regs to traps.c.
[S390] cio: Use strict_strtoul() for attributes. -
TIF_RESTORE_SIGMASK no longer needs to be in the _TIF_WORK_* masks. Those low
bits are scarce, and are all used up now. Renumber TIF_RESTORE_SIGMASK to
free one up.Signed-off-by: Roland McGrath
Cc: Oleg Nesterov
Cc: Ingo Molnar
Cc: Thomas Gleixner
Cc: Martin Schwidefsky
Cc: Heiko Carstens
Cc: "Luck, Tony"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Signed-off-by: Martin Schwidefsky
-
After the PT_IEEE_IP hack has been removed s390 can now use
the common code sys_ptrace function.Signed-off-by: Martin Schwidefsky
-
The self referential PT_IEEE_IP ptrace peek & poke calls have been
broken for that last 6 years. For peek the code always returns 0
instead of the last ieee fault and for poke the code does nothing.
Since nobody noticed the code seems to be superfluous. So lets
remove it.Cc: Christoph Hellwig
Signed-off-by: Martin Schwidefsky -
Convert s390 to SPARSEMEM and SPARSEMEM_VMEMMAP. We do a select
of SPARSEMEM_VMEMMAP since it is configurable. This is because
SPARSEMEM without SPARSEMEM_VMEMMAP gives us a hell of broken
include dependencies that I don't want to fix.Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky -
This adds hugetlbfs support on System z, using both hardware large page
support if available and software large page emulation on older hardware.
Shared (large) page tables are implemented in software emulation mode,
by using page->index of the first tail page from a compound large page
to store page table information.Signed-off-by: Gerald Schaefer
Signed-off-by: Martin Schwidefsky -
From: Heiko Carstens
From: Carsten OtteThis lets us use defines for the magic bits in machine flags instead
of using plain numbers all over the place.
In addition on newer machines features/facilities are indicated by the
result of the stfl instruction. So we use these bits instead of trying
to execute new instructions and check wether we get an exception or
not.
Also the mvpg instruction is always available when in zArch mode,
whereas the idte instruction is only available in zArch mode. This
results in some minor optimizations.Signed-off-by: Heiko Carstens
Signed-off-by: Carsten Otte
Signed-off-by: Martin Schwidefsky -
Always use clear_table to initialise page tables. The overlapping
memcpy is just a leftover of a previous version that wasn't fully
converted to clear_table.Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky -
Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky -
arch/s390/lib/uaccess_mvcos.c:166:
warning: 'strnlen_user_mvcos' defined but not used
arch/s390/lib/uaccess_mvcos.c:186:
warning: 'strncpy_from_user_mvcos' defined but not usedSigned-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky -
When we get a notification that cpu topology changed, we schedule a
work struct which just calls arch_reinit_sched_domains. This function
in turn calls get_online_cpus() which results int the lockdep warning
below.After all it turnded out that it's not legal to call get_online_cpus()
from the context of a multi-threaded work queue.
It could deadlock this way:process 0 (events/cpu-x):
-> run_workqueue
-> removes my work_struct from the work queue
-> calls work_struct->fn
-> get_online_cpus()
-> locks on cpu_hotplug.lock since process 1 below is doing cpu hotplugprocess 1:
-> cpu_down (for cpu-x)
-> cpu_hotplug_begin (holds cpu_hotplug.lock now)
-> cpu-x dead
-> notifier_call_chain with CPU_DEAD
-> cleanup_workqueue_thread
-> flush_cpu_workqueue (succeeds)
-> kthread_stop for events/cpu-x
-> now kthread_stop waits for my work_struct to complete from within
process 0. -> dead.A single threaded workqueue wouldn't have such problems, however there is
no such common queue available and it's not worth to create one for the
very rare calls to arch_reinit_sched_domains.So we just create a kernel thread from our work struct which calls
arch_reinit_sched_domains and are done with it.Thanks to Oleg Nesterov and Peter Zijlstra for helping me figuring out
that this isn't a false positive lockdep warning:=======================================================
[ INFO: possible circular locking dependency detected ]
2.6.25-03562-g3dc5063-dirty #12
-------------------------------------------------------
events/3/14 is trying to acquire lock:
(&cpu_hotplug.lock){--..}, at: [] get_online_cpus+0x50/0x78but task is already holding lock:
(topology_work){--..}, at: [] run_workqueue+0x106/0x278which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (topology_work){--..}:
[] __lock_acquire+0x1010/0x111c
[] lock_acquire+0xc0/0xf8
[] run_workqueue+0x170/0x278
[] worker_thread+0x8c/0xf0
[] kthread+0x68/0xa0
[] kernel_thread_starter+0x6/0xc
[] kernel_thread_starter+0x0/0xc-> #1 (events){--..}:
[] __lock_acquire+0x1010/0x111c
[] lock_acquire+0xc0/0xf8
[] cleanup_workqueue_thread+0x60/0xa8
[] workqueue_cpu_callback+0xbc/0x170
[] notifier_call_chain+0x5c/0xa4
[] __raw_notifier_call_chain+0x26/0x38
[] raw_notifier_call_chain+0x2e/0x40
[] cpu_down+0x228/0x31c
[] store_online+0x64/0xb8
[] sysdev_store+0x48/0x58
[] sysfs_write_file+0x126/0x1c0
[] vfs_write+0xb0/0x15c
[] sys_write+0x56/0x88
[] sys32_write+0x34/0x4c
[] sysc_noemu+0x10/0x16
[] 0x77f3f186-> #0 (&cpu_hotplug.lock){--..}:
[] __lock_acquire+0xe20/0x111c
[] lock_acquire+0xc0/0xf8
[] mutex_lock_nested+0xd0/0x364
[] get_online_cpus+0x50/0x78
[] arch_reinit_sched_domains+0x26/0x58
[] topology_work_fn+0x26/0x34
[] run_workqueue+0x176/0x278
[] worker_thread+0x8c/0xf0
[] kthread+0x68/0xa0
[] kernel_thread_starter+0x6/0xc
[] kernel_thread_starter+0x0/0xcother info that might help us debug this:
2 locks held by events/3/14:
#0: (events){--..}, at: [] run_workqueue+0x106/0x278
#1: (topology_work){--..}, at: [] run_workqueue+0x106/0x278stack backtrace:
CPU: 3 Not tainted 2.6.25-03562-g3dc5063-dirty #12
Process events/3 (pid: 14, task: 000000002fb04038, ksp: 000000002fb0bd70)
0400000000000000 000000002fb0ba40 0000000000000002 0000000000000000
000000002fb0bae0 000000002fb0ba58 000000002fb0ba58 0000000000016488
0000000000000000 000000002fb0bd70 0000000000000000 0000000000000000
000000002fb0ba40 000000000000000c 000000002fb0ba40 000000002fb0bab0
00000000003c99e0 0000000000016488 000000002fb0ba40 000000002fb0ba90
Call Trace:
([] show_trace+0x138/0x158)
[] show_stack+0xc6/0xf8
[] dump_stack+0xb0/0xc0
[] print_circular_bug_tail+0xa2/0xb4
[] __lock_acquire+0xe20/0x111c
[] lock_acquire+0xc0/0xf8
[] mutex_lock_nested+0xd0/0x364
[] get_online_cpus+0x50/0x78
[] arch_reinit_sched_domains+0x26/0x58
[] topology_work_fn+0x26/0x34
[] run_workqueue+0x176/0x278
[] worker_thread+0x8c/0xf0
[] kthread+0x68/0xa0
[] kernel_thread_starter+0x6/0xc
[] kernel_thread_starter+0x0/0xc
INFO: lockdep is turned off.Cc: Oleg Nesterov
Cc: Peter Zijlstra
Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky -
This exposes the core siblings to user space via sysfs.
Signed-off-by: Heiko Carstens
-
Signed-off-by: Mathieu Desnoyers
CC: Sam Ravnborg
Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky -
Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky -
On some smp sysfs store attributes get_online_cpus() may block on
cpu_hotplug.lock, but we hold already smp_cpu_state_mutex. Since the
locking order on cpu hotplug via arch_update_cpu_topology is inverse
this might lead to deadlocks.
So make sure locking order is always the same.Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky -
This is where it should be and we can get rid of some externs
and a static inline function.Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky
29 Apr, 2008
3 commits
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New version that does not preserve the marker. Arch maintainers indicate
that the marker functionality is is not needed anymore.Note you may simplify the s390 asm-offsets.c code further if you use the
OFFSET() macro instead of the DEFINE. See kbuild.hSigned-off-by: Christoph Lameter
Cc: Martin Schwidefsky
Cc: Heiko Carstens
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
s390 has a strange marker in DEFINE. Undefine the DEFINE from kbuild.h and
define it the way s390 wants it to preserve things as they were.May be good if the arch maintainer could go over this and check if this
workaround is really necessary.Signed-off-by: Christoph Lameter
Cc: Martin Schwidefsky
Cc: Heiko Carstens
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add a proper prototype for __do_softirq() in include/linux/interrupt.h
Signed-off-by: Adrian Bunk
Acked-by: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
27 Apr, 2008
11 commits
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So userspace can save/restore the mpstate during migration.
[avi: export the #define constants describing the value]
[christian: add s390 stubs]
[avi: ditto for ia64]Signed-off-by: Marcelo Tosatti
Signed-off-by: Christian Borntraeger
Signed-off-by: Carsten Otte
Signed-off-by: Avi Kivity -
Timers that fire between guest hlt and vcpu_block's add_wait_queue() are
ignored, possibly resulting in hangs.Also make sure that atomic_inc and waitqueue_active tests happen in the
specified order, otherwise the following race is open:CPU0 CPU1
if (waitqueue_active(wq))
add_wait_queue()
if (!atomic_read(pit_timer->pending))
schedule()
atomic_inc(pit_timer->pending)Signed-off-by: Marcelo Tosatti
Signed-off-by: Avi Kivity -
Signed-off-by: Avi Kivity
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Temporarily rename this function to avoid merge conflicts and/or
dependencies. This function will be removed as soon as git-s390
and kvm.git are finally upstream.Signed-off-by: Heiko Carstens
Signed-off-by: Carsten Otte
Signed-off-by: Avi Kivity -
kvm_arch_vcpu_ioctl_run currently incorrectly always returns 0.
Signed-off-by: Heiko Carstens
Signed-off-by: Carsten Otte
Signed-off-by: Avi Kivity -
This patch adds functionality to detect if the kernel runs under the KVM
hypervisor. A macro MACHINE_IS_KVM is exported for device drivers. This
allows drivers to skip device detection if the systems runs non-virtualized.
We also define a preferred console to avoid having the ttyS0, which is a line
mode only console.Signed-off-by: Christian Borntraeger
Acked-by: Martin Schwidefsky
Signed-off-by: Carsten Otte
Signed-off-by: Avi Kivity -
This patch adds the virtualization submenu and the kvm option to the kernel
config. It also defines HAVE_KVM for 64bit kernels.Acked-by: Martin Schwidefsky
Signed-off-by: Christian Borntraeger
Signed-off-by: Carsten Otte
Signed-off-by: Avi Kivity -
This patch introduces interpretation of some diagnose instruction intercepts.
Diagnose is our classic architected way of doing a hypercall. This patch
features the following diagnose codes:
- vm storage size, that tells the guest about its memory layout
- time slice end, which is used by the guest to indicate that it waits
for a lock and thus cannot use up its time slice in a useful way
- ipl functions, which a guest can use to reset and reboot itselfIn order to implement ipl functions, we also introduce an exit reason that
causes userspace to perform various resets on the virtual machine. All resets
are described in the principles of operation book, except KVM_S390_RESET_IPL
which causes a reboot of the machine.Acked-by: Martin Schwidefsky
Signed-off-by: Christian Borntraeger
Signed-off-by: Carsten Otte
Signed-off-by: Avi Kivity -
This patch introduces in-kernel handling of _some_ sigp interprocessor
signals (similar to ipi).
kvm_s390_handle_sigp() decodes the sigp instruction and calls individual
handlers depending on the operation requested:
- sigp sense tries to retrieve information such as existence or running state
of the remote cpu
- sigp emergency sends an external interrupt to the remove cpu
- sigp stop stops a remove cpu
- sigp stop store status stops a remote cpu, and stores its entire internal
state to the cpus lowcore
- sigp set arch sets the architecture mode of the remote cpu. setting to
ESAME (s390x 64bit) is accepted, setting to ESA/S390 (s390, 31 or 24 bit) is
denied, all others are passed to userland
- sigp set prefix sets the prefix register of a remote cpuFor implementation of this, the stop intercept indication starts to get reused
on purpose: a set of action bits defines what to do once a cpu gets stopped:
ACTION_STOP_ON_STOP really stops the cpu when a stop intercept is recognized
ACTION_STORE_ON_STOP stores the cpu status to lowcore when a stop intercept is
recognizedAcked-by: Martin Schwidefsky
Signed-off-by: Christian Borntraeger
Signed-off-by: Carsten Otte
Signed-off-by: Carsten Otte
Signed-off-by: Avi Kivity -
This patch introduces in-kernel handling of some intercepts for privileged
instructions:handle_set_prefix() sets the prefix register of the local cpu
handle_store_prefix() stores the content of the prefix register to memory
handle_store_cpu_address() stores the cpu number of the current cpu to memory
handle_skey() just decrements the instruction address and retries
handle_stsch() delivers condition code 3 "operation not supported"
handle_chsc() same here
handle_stfl() stores the facility list which contains the
capabilities of the cpu
handle_stidp() stores cpu type/model/revision and such
handle_stsi() stores information about the system topologyAcked-by: Martin Schwidefsky
Signed-off-by: Christian Borntraeger
Signed-off-by: Heiko Carstens
Signed-off-by: Carsten Otte
Signed-off-by: Avi Kivity -
This patch contains the s390 interrupt subsystem (similar to in kernel apic)
including timer interrupts (similar to in-kernel-pit) and enabled wait
(similar to in kernel hlt).In order to achieve that, this patch also introduces intercept handling
for instruction intercepts, and it implements load control instructions.This patch introduces an ioctl KVM_S390_INTERRUPT which is valid for both
the vm file descriptors and the vcpu file descriptors. In case this ioctl is
issued against a vm file descriptor, the interrupt is considered floating.
Floating interrupts may be delivered to any virtual cpu in the configuration.The following interrupts are supported:
SIGP STOP - interprocessor signal that stops a remote cpu
SIGP SET PREFIX - interprocessor signal that sets the prefix register of a
(stopped) remote cpu
INT EMERGENCY - interprocessor interrupt, usually used to signal need_reshed
and for smp_call_function() in the guest.
PROGRAM INT - exception during program execution such as page fault, illegal
instruction and friends
RESTART - interprocessor signal that starts a stopped cpu
INT VIRTIO - floating interrupt for virtio signalisation
INT SERVICE - floating interrupt for signalisations from the system
service processorstruct kvm_s390_interrupt, which is submitted as ioctl parameter when injecting
an interrupt, also carrys parameter data for interrupts along with the interrupt
type. Interrupts on s390 usually have a state that represents the current
operation, or identifies which device has caused the interruption on s390.kvm_s390_handle_wait() does handle waitpsw in two flavors: in case of a
disabled wait (that is, disabled for interrupts), we exit to userspace. In case
of an enabled wait we set up a timer that equals the cpu clock comparator value
and sleep on a wait queue.[christian: change virtio interrupt to 0x2603]
Acked-by: Martin Schwidefsky
Signed-off-by: Heiko Carstens
Signed-off-by: Carsten Otte
Signed-off-by: Christian Borntraeger
Signed-off-by: Avi Kivity
