Commit Graph

287 Commits

Author SHA1 Message Date
Lai Jiangshan
90d83dc3d4 KVM: use the correct RCU API for PROVE_RCU=y
The RCU/SRCU API have already changed for proving RCU usage.

I got the following dmesg when PROVE_RCU=y because we used incorrect API.
This patch coverts rcu_deference() to srcu_dereference() or family API.

===================================================
[ INFO: suspicious rcu_dereference_check() usage. ]
---------------------------------------------------
arch/x86/kvm/mmu.c:3020 invoked rcu_dereference_check() without protection!

other info that might help us debug this:

rcu_scheduler_active = 1, debug_locks = 0
2 locks held by qemu-system-x86/8550:
 #0:  (&kvm->slots_lock){+.+.+.}, at: [<ffffffffa011a6ac>] kvm_set_memory_region+0x29/0x50 [kvm]
 #1:  (&(&kvm->mmu_lock)->rlock){+.+...}, at: [<ffffffffa012262d>] kvm_arch_commit_memory_region+0xa6/0xe2 [kvm]

stack backtrace:
Pid: 8550, comm: qemu-system-x86 Not tainted 2.6.34-rc4-tip-01028-g939eab1 #27
Call Trace:
 [<ffffffff8106c59e>] lockdep_rcu_dereference+0xaa/0xb3
 [<ffffffffa012f6c1>] kvm_mmu_calculate_mmu_pages+0x44/0x7d [kvm]
 [<ffffffffa012263e>] kvm_arch_commit_memory_region+0xb7/0xe2 [kvm]
 [<ffffffffa011a5d7>] __kvm_set_memory_region+0x636/0x6e2 [kvm]
 [<ffffffffa011a6ba>] kvm_set_memory_region+0x37/0x50 [kvm]
 [<ffffffffa015e956>] vmx_set_tss_addr+0x46/0x5a [kvm_intel]
 [<ffffffffa0126592>] kvm_arch_vm_ioctl+0x17a/0xcf8 [kvm]
 [<ffffffff810a8692>] ? unlock_page+0x27/0x2c
 [<ffffffff810bf879>] ? __do_fault+0x3a9/0x3e1
 [<ffffffffa011b12f>] kvm_vm_ioctl+0x364/0x38d [kvm]
 [<ffffffff81060cfa>] ? up_read+0x23/0x3d
 [<ffffffff810f3587>] vfs_ioctl+0x32/0xa6
 [<ffffffff810f3b19>] do_vfs_ioctl+0x495/0x4db
 [<ffffffff810e6b2f>] ? fget_light+0xc2/0x241
 [<ffffffff810e416c>] ? do_sys_open+0x104/0x116
 [<ffffffff81382d6d>] ? retint_swapgs+0xe/0x13
 [<ffffffff810f3ba6>] sys_ioctl+0x47/0x6a
 [<ffffffff810021db>] system_call_fastpath+0x16/0x1b

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-05-17 12:18:01 +03:00
Wei Yongjun
7b06bf2ffa KVM: s390: Fix possible memory leak of in kvm_arch_vcpu_create()
This patch fixed possible memory leak in kvm_arch_vcpu_create()
under s390, which would happen when kvm_arch_vcpu_create() fails.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Acked-by: Carsten Otte <cotte@de.ibm.com>
Cc: stable@kernel.org
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-05-17 12:15:19 +03:00
Carsten Otte
cd3b70f5d4 [S390] virtualization aware cpu measurement
Use the SPP instruction to set a tag on entry to / exit of the virtual
machine context. This allows the cpu measurement facility to distinguish
the samples from the host and the different guests.

Signed-off-by: Carsten Otte <cotte@de.ibm.com>
2010-05-17 10:00:15 +02:00
Tejun Heo
5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
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>
2010-03-30 22:02:32 +09:00
Linus Torvalds
c812a51d11 Merge branch 'kvm-updates/2.6.34' of git://git.kernel.org/pub/scm/virt/kvm/kvm
* 'kvm-updates/2.6.34' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (145 commits)
  KVM: x86: Add KVM_CAP_X86_ROBUST_SINGLESTEP
  KVM: VMX: Update instruction length on intercepted BP
  KVM: Fix emulate_sys[call, enter, exit]()'s fault handling
  KVM: Fix segment descriptor loading
  KVM: Fix load_guest_segment_descriptor() to inject page fault
  KVM: x86 emulator: Forbid modifying CS segment register by mov instruction
  KVM: Convert kvm->requests_lock to raw_spinlock_t
  KVM: Convert i8254/i8259 locks to raw_spinlocks
  KVM: x86 emulator: disallow opcode 82 in 64-bit mode
  KVM: x86 emulator: code style cleanup
  KVM: Plan obsolescence of kernel allocated slots, paravirt mmu
  KVM: x86 emulator: Add LOCK prefix validity checking
  KVM: x86 emulator: Check CPL level during privilege instruction emulation
  KVM: x86 emulator: Fix popf emulation
  KVM: x86 emulator: Check IOPL level during io instruction emulation
  KVM: x86 emulator: fix memory access during x86 emulation
  KVM: x86 emulator: Add Virtual-8086 mode of emulation
  KVM: x86 emulator: Add group9 instruction decoding
  KVM: x86 emulator: Add group8 instruction decoding
  KVM: do not store wqh in irqfd
  ...

Trivial conflicts in Documentation/feature-removal-schedule.txt
2010-03-05 13:12:34 -08:00
Marcelo Tosatti
6474920477 KVM: fix cleanup_srcu_struct on vm destruction
cleanup_srcu_struct on VM destruction remains broken:

BUG: unable to handle kernel paging request at ffffffffffffffff
IP: [<ffffffff802533d2>] srcu_read_lock+0x16/0x21
RIP: 0010:[<ffffffff802533d2>]  [<ffffffff802533d2>] srcu_read_lock+0x16/0x21
Call Trace:
 [<ffffffffa05354c4>] kvm_arch_vcpu_uninit+0x1b/0x48 [kvm]
 [<ffffffffa05339c6>] kvm_vcpu_uninit+0x9/0x15 [kvm]
 [<ffffffffa0569f7d>] vmx_free_vcpu+0x7f/0x8f [kvm_intel]
 [<ffffffffa05357b5>] kvm_arch_destroy_vm+0x78/0x111 [kvm]
 [<ffffffffa053315b>] kvm_put_kvm+0xd4/0xfe [kvm]

Move it to kvm_arch_destroy_vm.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Reported-by: Jan Kiszka <jan.kiszka@siemens.com>
2010-03-01 12:36:01 -03:00
Marcelo Tosatti
f656ce0185 KVM: switch vcpu context to use SRCU
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01 12:35:45 -03:00
Marcelo Tosatti
f7784b8ec9 KVM: split kvm_arch_set_memory_region into prepare and commit
Required for SRCU convertion later.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01 12:35:44 -03:00
David S. Miller
47871889c6 Merge branch 'master' of /home/davem/src/GIT/linux-2.6/
Conflicts:
	drivers/firmware/iscsi_ibft.c
2010-02-28 19:23:06 -08:00
Heiko Carstens
cbb870c822 [S390] Cleanup struct _lowcore usage and defines.
Use asm offsets to make sure the offset defines to struct _lowcore and
its layout don't get out of sync.
Also add a BUILD_BUG_ON() which checks that the size of the structure
is sane.
And while being at it change those sites which use odd casts to access
the current lowcore. These should use S390_lowcore instead.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-02-26 22:37:31 +01:00
Heiko Carstens
b8e660b83d [S390] Replace ENOTSUPP usage with EOPNOTSUPP
ENOTSUPP is not supposed to leak to userspace so lets just use
EOPNOTSUPP everywhere.
Doesn't fix a bug, but makes future reviews easier.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-02-26 22:37:31 +01:00
Heiko Carstens
f64ca21714 [S390] zfcpdump: remove cross arch dump support
Remove support to be able to dump 31 bit systems with a 64 bit dumper.
This is mostly useless since no distro ships 31 bit kernels together
with a 64 bit dumper.
We also get rid of a bit of hacky code.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-02-26 22:37:30 +01:00
David S. Miller
2bb4646fce Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-02-16 22:09:29 -08:00
Christian Borntraeger
062d5e9b0d KVM: S390: fix potential array overrun in intercept handling
kvm_handle_sie_intercept uses a jump table to get the intercept handler
for a SIE intercept. Static code analysis revealed a potential problem:
the intercept_funcs jump table was defined to contain (0x48 >> 2) entries,
but we only checked for code > 0x48 which would cause an off-by-one
array overflow if code == 0x48.

Use the compiler and ARRAY_SIZE to automatically set the limits.

Cc: stable@kernel.org
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-01-25 12:26:39 -02:00
Michael S. Tsirkin
3a4d5c94e9 vhost_net: a kernel-level virtio server
What it is: vhost net is a character device that can be used to reduce
the number of system calls involved in virtio networking.
Existing virtio net code is used in the guest without modification.

There's similarity with vringfd, with some differences and reduced scope
- uses eventfd for signalling
- structures can be moved around in memory at any time (good for
  migration, bug work-arounds in userspace)
- write logging is supported (good for migration)
- support memory table and not just an offset (needed for kvm)

common virtio related code has been put in a separate file vhost.c and
can be made into a separate module if/when more backends appear.  I used
Rusty's lguest.c as the source for developing this part : this supplied
me with witty comments I wouldn't be able to write myself.

What it is not: vhost net is not a bus, and not a generic new system
call. No assumptions are made on how guest performs hypercalls.
Userspace hypervisors are supported as well as kvm.

How it works: Basically, we connect virtio frontend (configured by
userspace) to a backend. The backend could be a network device, or a tap
device.  Backend is also configured by userspace, including vlan/mac
etc.

Status: This works for me, and I haven't see any crashes.
Compared to userspace, people reported improved latency (as I save up to
4 system calls per packet), as well as better bandwidth and CPU
utilization.

Features that I plan to look at in the future:
- mergeable buffers
- zero copy
- scalability tuning: figure out the best threading model to use

Note on RCU usage (this is also documented in vhost.h, near
private_pointer which is the value protected by this variant of RCU):
what is happening is that the rcu_dereference() is being used in a
workqueue item.  The role of rcu_read_lock() is taken on by the start of
execution of the workqueue item, of rcu_read_unlock() by the end of
execution of the workqueue item, and of synchronize_rcu() by
flush_workqueue()/flush_work(). In the future we might need to apply
some gcc attribute or sparse annotation to the function passed to
INIT_WORK(). Paul's ack below is for this RCU usage.

(Includes fixes by Alan Cox <alan@linux.intel.com>,
David L Stevens <dlstevens@us.ibm.com>,
Chris Wright <chrisw@redhat.com>)

Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-01-15 01:43:29 -08:00
Linus Torvalds
67dd2f5a66 Merge branch 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6
* 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6: (72 commits)
  [S390] 3215/3270 console: remove wrong comment
  [S390] dasd: remove BKL from extended error reporting code
  [S390] vmlogrdr: remove BKL
  [S390] vmur: remove BKL
  [S390] zcrypt: remove BKL
  [S390] 3270: remove BKL
  [S390] vmwatchdog: remove lock_kernel() from open() function
  [S390] monwriter: remove lock_kernel() from open() function
  [S390] monreader: remove lock_kernel() from open() function
  [S390] s390: remove unused nfsd #includes
  [S390] ftrace: build ftrace.o when CONFIG_FTRACE_SYSCALLS is set for s390
  [S390] etr/stp: put correct per cpu variable
  [S390] tty3270: move keyboard compat ioctls
  [S390] sclp: improve servicability setting
  [S390] s390: use change recording override for kernel mapping
  [S390] MAINTAINERS: Add s390 drivers block
  [S390] use generic sockios.h header file
  [S390] use generic termbits.h header file
  [S390] smp: remove unused typedef and defines
  [S390] cmm: free pages on hibernate.
  ...
2009-12-09 19:01:47 -08:00
Martin Schwidefsky
b11b533427 [S390] Improve address space mode selection.
Introduce user_mode to replace the two variables switch_amode and
s390_noexec. There are three valid combinations of the old values:
  1) switch_amode == 0 && s390_noexec == 0
  2) switch_amode == 1 && s390_noexec == 0
  3) switch_amode == 1 && s390_noexec == 1
They get replaced by
  1) user_mode == HOME_SPACE_MODE
  2) user_mode == PRIMARY_SPACE_MODE
  3) user_mode == SECONDARY_SPACE_MODE
The new kernel parameter user_mode=[primary,secondary,home] lets
you choose the address space mode the user space processes should
use. In addition the CONFIG_S390_SWITCH_AMODE config option
is removed.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07 12:51:33 +01:00
Carsten Otte
f50146bd7b KVM: s390: Fix prefix register checking in arch/s390/kvm/sigp.c
This patch corrects the checking of the new address for the prefix register.
On s390, the prefix register is used to address the cpu's lowcore (address
0...8k). This check is supposed to verify that the memory is readable and
present.
copy_from_guest is a helper function, that can be used to read from guest
memory. It applies prefixing, adds the start address of the guest memory in
user, and then calls copy_from_user. Previous code was obviously broken for
two reasons:
- prefixing should not be applied here. The current prefix register is
  going to be updated soon, and the address we're looking for will be
  0..8k after we've updated the register
- we're adding the guest origin (gmsor) twice: once in subject code
  and once in copy_from_guest

With kuli, we did not hit this problem because (a) we were lucky with
previous prefix register content, and (b) our guest memory was mmaped
very low into user address space.

Cc: stable@kernel.org
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Reported-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-12-03 09:32:26 +02:00
Carsten Otte
d7b0b5eb30 KVM: s390: Make psw available on all exits, not just a subset
This patch moves s390 processor status word into the base kvm_run
struct and keeps it up-to date on all userspace exits.

The userspace ABI is broken by this, however there are no applications
in the wild using this.  A capability check is provided so users can
verify the updated API exists.

Cc: stable@kernel.org
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-12-03 09:32:25 +02:00
Alexander Graf
10474ae894 KVM: Activate Virtualization On Demand
X86 CPUs need to have some magic happening to enable the virtualization
extensions on them. This magic can result in unpleasant results for
users, like blocking other VMMs from working (vmx) or using invalid TLB
entries (svm).

Currently KVM activates virtualization when the respective kernel module
is loaded. This blocks us from autoloading KVM modules without breaking
other VMMs.

To circumvent this problem at least a bit, this patch introduces on
demand activation of virtualization. This means, that instead
virtualization is enabled on creation of the first virtual machine
and disabled on destruction of the last one.

So using this, KVM can be easily autoloaded, while keeping other
hypervisors usable.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-12-03 09:32:10 +02:00
Avi Kivity
367e1319b2 KVM: Return -ENOTTY on unrecognized ioctls
Not the incorrect -EINVAL.

Signed-off-by: Avi Kivity <avi@redhat.com>
2009-12-03 09:32:08 +02:00
Christian Borntraeger
8feda6f786 KVM: s390: fix memsize >= 4G
commit 628eb9b8a8
    KVM: s390: streamline memslot handling

introduced kvm_s390_vcpu_get_memsize. This broke guests >=4G, since this
function returned an int.

This patch changes the return value to a long.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-10-04 13:57:23 +02:00
Joe Perches
a419aef8b8 trivial: remove unnecessary semicolons
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-09-21 15:14:58 +02:00
Gleb Natapov
a1b37100d9 KVM: Reduce runnability interface with arch support code
Remove kvm_cpu_has_interrupt() and kvm_arch_interrupt_allowed() from
interface between general code and arch code. kvm_arch_vcpu_runnable()
checks for interrupts instead.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 08:33:13 +03:00
Marcelo Tosatti
2023a29cbe KVM: remove old KVMTRACE support code
Return EOPNOTSUPP for KVM_TRACE_ENABLE/PAUSE/DISABLE ioctls.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 08:33:03 +03:00
Gleb Natapov
988a2cae6a KVM: Use macro to iterate over vcpus.
[christian: remove unused variables on s390]

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 08:32:52 +03:00
Christian Ehrhardt
628eb9b8a8 KVM: s390: streamline memslot handling
This patch relocates the variables kvm-s390 uses to track guest mem addr/size.
As discussed dropping the variables at struct kvm_arch level allows to use the
common vcpu->request based mechanism to reload guest memory if e.g. changes
via set_memory_region.

The kick mechanism introduced in this series is used to ensure running vcpus
leave guest state to catch the update.

Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 08:32:42 +03:00
Christian Ehrhardt
b1d16c495d KVM: s390: fix signal handling
If signal pending is true we exit without updating kvm_run, userspace
currently just does nothing and jumps to kvm_run again.
Since we did not set an exit_reason we might end up with a random one
(whatever was the last exit). Therefore it was possible to e.g. jump to
the psw position the last real interruption set.
Setting the INTR exit reason ensures that no old psw data is swapped
in on reentry.

Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 08:32:42 +03:00
Christian Ehrhardt
9ace903d17 KVM: s390: infrastructure to kick vcpus out of guest state
To ensure vcpu's come out of guest context in certain cases this patch adds a
s390 specific way to kick them out of guest context. Currently it kicks them
out to rerun the vcpu_run path in the s390 code, but the mechanism itself is
expandable and with a new flag we could also add e.g. kicks to userspace etc.

Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 08:32:42 +03:00
Avi Kivity
0ba12d1081 KVM: Move common KVM Kconfig items to new file virt/kvm/Kconfig
Reduce Kconfig code duplication.

Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 08:32:41 +03:00
Linus Torvalds
17d11ba149 Merge branch 'kvm-updates/2.6.31' of git://git.kernel.org/pub/scm/virt/kvm/kvm
* 'kvm-updates/2.6.31' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: Avoid redelivery of edge interrupt before next edge
  KVM: MMU: limit rmap chain length
  KVM: ia64: fix build failures due to ia64/unsigned long mismatches
  KVM: Make KVM_HPAGES_PER_HPAGE unsigned long to avoid build error on powerpc
  KVM: fix ack not being delivered when msi present
  KVM: s390: fix wait_queue handling
  KVM: VMX: Fix locking imbalance on emulation failure
  KVM: VMX: Fix locking order in handle_invalid_guest_state
  KVM: MMU: handle n_free_mmu_pages > n_alloc_mmu_pages in kvm_mmu_change_mmu_pages
  KVM: SVM: force new asid on vcpu migration
  KVM: x86: verify MTRR/PAT validity
  KVM: PIT: fix kpit_elapsed division by zero
  KVM: Fix KVM_GET_MSR_INDEX_LIST
2009-08-09 14:58:21 -07:00
Roel Kluin
53cb780adb [S390] KVM: Read buffer overflow
Check whether index is within bounds before testing the element.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-08-07 10:40:40 +02:00
Christian Borntraeger
d3bc2f91b4 KVM: s390: fix wait_queue handling
There are two waitqueues in kvm for wait handling:
vcpu->wq for virt/kvm/kvm_main.c and
vpcu->arch.local_int.wq for the s390 specific wait code.

the wait handling in kvm_s390_handle_wait was broken by using different
wait_queues for add_wait queue and remove_wait_queue.

There are two options to fix the problem:
o  move all the s390 specific code to vcpu->wq and remove
   vcpu->arch.local_int.wq
o  move all the s390 specific code to vcpu->arch.local_int.wq

This patch chooses the 2nd variant for two reasons:
o  s390 does not use kvm_vcpu_block but implements its own enabled wait
   handling.
   Having a separate wait_queue make it clear, that our wait mechanism is
   different
o  the patch is much smaller

Report-by:  Julia Lawall <julia@diku.dk>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-08-05 13:59:46 +03:00
Christian Borntraeger
ef50f7ac7e KVM: s390: Allow stfle instruction in the guest
2.6.31-rc introduced an architecture level set checker based on facility
bits. e.g. if the kernel is compiled to run only on z9, several facility
bits are checked very early and the kernel refuses to boot if a z9 specific
facility is missing.
Until now kvm on s390 did not implement the store facility extended (STFLE)
instruction. A 2.6.31-rc kernel that was compiled for z9 or higher did not
boot in kvm. This patch implements stfle.

This patch should go in before 2.6.31.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-06-28 14:10:30 +03:00
Heiko Carstens
dab4079d5b [S390] uaccess: use might_fault() instead of might_sleep()
Adds more checking in case lockdep is turned on.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-06-12 10:27:33 +02:00
Carsten Otte
51e4d5ab28 KVM: s390: Verify memory in kvm run
This check verifies that the guest we're trying to run in KVM_RUN
has some memory assigned to it. It enters an endless exception
loop if this is not the case.

Reported-by: Mijo Safradin <mijo@linux.vnet.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Christian Ehrhardt <ehrhardt@de.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-06-10 11:48:57 +03:00
Carsten Otte
3edbcff9bf KVM: s390: Sanity check on validity intercept
This patch adds a sanity check for the content of the guest
prefix register content before faulting in the cpu lowcore
that it refers to. The guest might end up in an endless loop
where SIE complains about missing lowcore with incorrect
content of the prefix register without this fix.

Reported-by: Mijo Safradin <mijo@linux.vnet.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Christian Ehrhardt <ehrhardt@de.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-06-10 11:48:56 +03:00
Carsten Otte
abf4a71ed9 KVM: s390: Unlink vcpu on destroy - v2
This patch makes sure we do unlink a vcpu's sie control block
from the system control area in kvm_arch_vcpu_destroy. This
prevents illegal accesses to the sie control block from other
virtual cpus after free.

Reported-by: Mijo Safradin <mijo@linux.vnet.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Christian Ehrhardt <ehrhardt@de.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-06-10 11:48:56 +03:00
Christian Borntraeger
b037a4f34e KVM: s390: optimize float int lock: spin_lock_bh --> spin_lock
The floating interrupt lock is only taken in process context. We can
replace all spin_lock_bh with standard spin_lock calls.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Ehrhardt <ehrhardt@de.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-06-10 11:48:56 +03:00
Christian Borntraeger
ca8723023f KVM: s390: use hrtimer for clock wakeup from idle - v2
This patch reworks the s390 clock comparator wakeup to hrtimer. The clock
comparator is a per-cpu value that is compared against the TOD clock. If
ckc <= TOD an external interrupt 1004 is triggered. Since the clock comparator
and the TOD clock have a much higher resolution than jiffies we should use
hrtimers to trigger the wakeup. This speeds up guest nanosleep for small
values.

Since hrtimers callbacks run in hard-irq context, I added a tasklet to do
the actual work with enabled interrupts.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Christian Ehrhardt <ehrhardt@de.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-06-10 11:48:55 +03:00
Carsten Otte
2668dab794 KVM: s390: Fix memory slot versus run - v3
This patch fixes an incorrectness in the kvm backend for s390.
In case virtual cpus are being created before the corresponding
memory slot is being registered, we need to update the sie
control blocks for the virtual cpus.

*updates in v3*
In consideration of the s390 memslot constraints locking was changed
to trylock. These locks should never be held, as vcpu's can't run without
the single memslot we just assign when running this code. To ensure this
never deadlocks in case other code changes the code uses trylocks and bail
out if it can't get all locks.

Additionally most of the discussed special conditions for s390 like
only one memslot and no user_alloc are now checked for validity in
kvm_arch_set_memory_region.

Reported-by: Mijo Safradin <mijo@linux.vnet.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Christian Ehrhardt <ehrhardt@de.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-06-10 11:48:55 +03:00
Gleb Natapov
78646121e9 KVM: Fix interrupt unhalting a vcpu when it shouldn't
kvm_vcpu_block() unhalts vpu on an interrupt/timer without checking
if interrupt window is actually opened.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-06-10 11:48:33 +03:00
Linus Torvalds
21cdbc1378 Merge branch 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6
* 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6: (81 commits)
  [S390] remove duplicated #includes
  [S390] cpumask: use mm_cpumask() wrapper
  [S390] cpumask: Use accessors code.
  [S390] cpumask: prepare for iterators to only go to nr_cpu_ids/nr_cpumask_bits.
  [S390] cpumask: remove cpu_coregroup_map
  [S390] fix clock comparator save area usage
  [S390] Add hwcap flag for the etf3 enhancement facility
  [S390] Ensure that ipl panic notifier is called late.
  [S390] fix dfp elf hwcap/facility bit detection
  [S390] smp: perform initial cpu reset before starting a cpu
  [S390] smp: fix memory leak on __cpu_up
  [S390] ipl: Improve checking logic and remove switch defaults.
  [S390] s390dbf: Remove needless check for NULL pointer.
  [S390] s390dbf: Remove redundant initilizations.
  [S390] use kzfree()
  [S390] BUG to BUG_ON changes
  [S390] zfcpdump: Prevent zcore from beeing built as a kernel module.
  [S390] Use csum_partial in checksum.h
  [S390] cleanup lowcore.h
  [S390] eliminate ipl_device from lowcore
  ...
2009-03-26 16:04:22 -07:00
Heiko Carstens
f5daba1d41 [S390] split/move machine check handler code
Split machine check handler code and move it to cio and kernel code
where it belongs to. No functional change.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-03-26 15:24:10 +01:00
Christian Borntraeger
92e6ecf392 [S390] Fix hypervisor detection for KVM
Currently we use the cpuid (via STIDP instruction) to recognize LPAR,
z/VM and KVM.
The architecture states, that bit 0-7 of STIDP returns all zero, and
if STIDP is executed in a virtual machine, the VM operating system
will replace bits 0-7 with FF.

KVM should not use FE to distinguish z/VM from KVM for interested
guests. The proper way to detect the hypervisor is the STSI (Store
System Information) instruction, which return information about the
hypervisors via function code 3, selector1=2, selector2=2.

This patch changes the detection routine of Linux to use STSI instead
of STIDP. This detection is earlier than bootmem, we have to use a
static buffer. Since STSI expects a 4kb block (4kb aligned) this
patch also changes the init.data alignment for s390. As this section
will be freed during boot, this should be no problem.

Patch is tested with LPAR, z/VM, KVM on LPAR, and KVM under z/VM.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-03-26 15:24:09 +01:00
Christian Borntraeger
b7e6e4d360 KVM: s390: Fix SIGP set prefix ioctl
This patch fixes the SET PREFIX interrupt if triggered by userspace.
Until now, it was not necessary, but life migration will need it. In
addition, it helped me creating SMP support for my kvm_crashme tool
(lets kvm execute random guest memory content).

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24 11:03:07 +02:00
Christian Borntraeger
70455a36a0 KVM: s390: Fix problem state check for b2 intercepts
The kernel handles some priviledged instruction exits. While I was
unable to trigger such an exit from guest userspace, the code should
check for supervisor state before emulating a priviledged instruction.

I also renamed kvm_s390_handle_priv to kvm_s390_handle_b2. After all
there are non priviledged b2 instructions like stck (store clock).

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24 11:03:07 +02:00
Christian Borntraeger
2c411b48af KVM: s390: Fix printk on SIGP set arch
KVM on s390 does not support the ESA/390 architecture. We refuse to
change the architecture mode and print a warning. This patch removes
the printk for several reasons:

o A malicious guest can flood host dmesg
o The old message had no newline
o there is no connection between the message and the failing guest

This patch simply removes the printk. We already set the condition
code to 3 - the guest knows that something went wrong.

Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24 11:03:07 +02:00
Avi Kivity
5d9b8e30f5 KVM: Add CONFIG_HAVE_KVM_IRQCHIP
Two KVM archs support irqchips and two don't.  Add a Kconfig item to
make selecting between the two models easier.

Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24 11:03:02 +02:00
Jan Kiszka
d0bfb940ec KVM: New guest debug interface
This rips out the support for KVM_DEBUG_GUEST and introduces a new IOCTL
instead: KVM_SET_GUEST_DEBUG. The IOCTL payload consists of a generic
part, controlling the "main switch" and the single-step feature. The
arch specific part adds an x86 interface for intercepting both types of
debug exceptions separately and re-injecting them when the host was not
interested. Moveover, the foundation for guest debugging via debug
registers is layed.

To signal breakpoint events properly back to userland, an arch-specific
data block is now returned along KVM_EXIT_DEBUG. For x86, the arch block
contains the PC, the debug exception, and relevant debug registers to
tell debug events properly apart.

The availability of this new interface is signaled by
KVM_CAP_SET_GUEST_DEBUG. Empty stubs for not yet supported archs are
provided.

Note that both SVM and VTX are supported, but only the latter was tested
yet. Based on the experience with all those VTX corner case, I would be
fairly surprised if SVM will work out of the box.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24 11:02:49 +02:00
Sheng Yang
ad8ba2cd44 KVM: Add kvm_arch_sync_events to sync with asynchronize events
kvm_arch_sync_events is introduced to quiet down all other events may happen
contemporary with VM destroy process, like IRQ handler and work struct for
assigned device.

For kvm_arch_sync_events is called at the very beginning of kvm_destroy_vm(), so
the state of KVM here is legal and can provide a environment to quiet down other
events.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-02-15 02:47:36 +02:00
Heiko Carstens
33e1911566 [S390] Use unsigned long long for u64 on 64bit.
As requested by Andrew. Same as what sparc did.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-01-09 12:15:07 +01:00
Avi Kivity
ca9edaee1a KVM: Consolidate userspace memory capability reporting into common code
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:55:46 +02:00
Christian Borntraeger
6692cef30b KVM: s390: Fix memory leak of vcpu->run
The s390 backend of kvm never calls kvm_vcpu_uninit. This causes
a memory leak of vcpu->run pages.
Lets call kvm_vcpu_uninit in kvm_arch_vcpu_destroy to free
the vcpu->run.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:55:03 +02:00
Christian Borntraeger
d329c035e7 KVM: s390: Fix refcounting and allow module unload
Currently it is impossible to unload the kvm module on s390.
This patch fixes kvm_arch_destroy_vm to release all cpus.
This make it possible to unload the module.

In addition we stop messing with the module refcount in arch code.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:55:03 +02:00
Christian Borntraeger
3eb77d5116 KVM: s390: Fix problem state handling in guest sigp handler
We can get an exit for instructions starting with 0xae, even if the guest is
in userspace. Lets make sure, that the signal processor handler is only called
in guest supervisor mode. Otherwise, send a program check.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-11-23 14:34:39 +02:00
Christian Borntraeger
a0046b6db1 KVM: s390: Make facility bits future-proof
Heiko Carstens pointed out, that its safer to activate working facilities
instead of disabling problematic facilities. The new code uses the host
facility bits and masks it with known good ones.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:24 +02:00
Christian Borntraeger
1f4170e12d KVM: s390: Fix kvm on IBM System z10
The z10 system supports large pages, kvm-s390 doesnt.
Make sure that we dont advertise large pages to avoid the guest crashing as
soon as the guest kernel activates DAT.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-31 11:57:18 +03:00
Christian Borntraeger
5a00a5e7a3 KVM: s390: Fix possible host kernel bug on lctl(g) handling
The lctl(g) instructions require a specific alignment for the parameters.
The architecture requires a specification program check if these alignments
are not used. Enforcing this alignment also removes a possible host BUG,
since the get_guest functions check for proper alignment and emits a BUG.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-27 11:36:20 +03:00
Christian Borntraeger
f5e10b09a5 KVM: s390: Fix instruction naming for lctlg
Lets fix the name for the lctlg instruction...

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-27 11:36:12 +03:00
Christian Borntraeger
3cd612998f KVM: s390: Fix program check on interrupt delivery handling
The current interrupt handling on s390 misbehaves on an error case. On s390
each cpu has the prefix area (lowcore) for interrupt delivery. This memory
must always be available. If we fail to access the prefix area for a guest
on interrupt delivery the configuration is completely unusable. There is no
point in sending another program interrupt to an inaccessible lowcore.
Furthermore, we should not bug the host kernel, because this can be triggered
by userspace. I think the guest kernel itself can not trigger the problem, as
SET PREFIX and SIGNAL PROCESSOR SET PREFIX both check that the memory is
available and sane. As this is a userspace bug (e.g. setting the wrong guest
offset, unmapping guest memory) we should kill the userspace process instead
of BUGing the host kernel.
In the long term we probably should notify the userspace process about this
problem.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-27 11:36:05 +03:00
Martin Schwidefsky
0096369daa KVM: s390: Change guestaddr type in gaccess
All registers are unsigned long types. This patch changes all occurences
of guestaddr in gaccess from u64 to unsigned long.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-27 11:35:57 +03:00
Carsten Otte
2bd0ac4eb4 KVM: s390: Advertise KVM_CAP_USER_MEMORY
KVM_CAP_USER_MEMORY is used by s390, therefore, we should advertise it.

Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-27 11:35:40 +03:00
Marcelo Tosatti
34d4cb8fca KVM: MMU: nuke shadowed pgtable pages and ptes on memslot destruction
Flush the shadow mmu before removing regions to avoid stale entries.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:40 +03:00
Christian Borntraeger
180c12fb22 KVM: s390: rename private structures
While doing some tests with our lcrash implementation I have seen a
naming conflict with prefix_info in kvm_host.h vs. addrconf.h

To avoid future conflicts lets rename private definitions in
asm/kvm_host.h by adding the kvm_s390 prefix.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:37 +03:00
Christian Borntraeger
4da29e909e KVM: s390: Set guest storage limit and offset to sane values
Some machines do not accept 16EB as guest storage limit. Lets change the
default for the guest storage limit to a sane value. We also should set
the guest_origin to what userspace thinks it is. This allows guests
starting at an address != 0.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:37 +03:00
Carsten Otte
dfdded7c41 KVM: Fix memory leak on guest exit
This patch fixes a memory leak, we want to free the physmem when destroying
the vm.

Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:37 +03:00
Avi Kivity
7cc8883074 KVM: Remove decache_vcpus_on_cpu() and related callbacks
Obsoleted by the vmx-specific per-cpu list.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:25 +03:00
Carsten Otte
e52b2af541 KVM: s390: Fix race condition in kvm_s390_handle_wait
The call to add_timer was issued before local_int.lock was taken and before
timer_due was set to 0. If the timer expires before the lock is being taken,
the timer function will set timer_due to 1 and exit before the vcpu falls
asleep. Depending on other external events, the vcpu might sleep forever.
This fix pulls setting timer_due to the beginning of the function before
add_timer, which ensures correct behavior.

Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-06 21:08:26 +03:00
Carsten Otte
1f0d0f094d KVM: s390: Send program check on access error
If the guest accesses non-existing memory, the sie64a function returns
-EFAULT. We must check the return value and send a program check to the
guest if the sie instruction faulted, otherwise the guest will loop at
the faulting code.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-06 21:08:26 +03:00
Carsten Otte
0ff3186745 KVM: s390: fix interrupt delivery
The current code delivers pending interrupts before it checks for
need_resched. On a busy host, this can lead to a longer interrupt
latency if the interrupt is injected while the process is scheduled
away. This patch moves delivering the interrupt _after_ schedule(),
which makes more sense.

Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-06 21:08:26 +03:00
Christian Borntraeger
71cde5879f KVM: s390: handle machine checks when guest is running
The low-level interrupt handler on s390 checks for _TIF_WORK_INT and
exits the guest context, if work is pending.
TIF_WORK_INT is defined as_TIF_SIGPENDING | _TIF_NEED_RESCHED |
 _TIF_MCCK_PENDING. Currently the sie loop checks for signals and
reschedule, but it does not check for machine checks. That means that
we exit the guest context if a machine check is pending, but we do not
handle the machine check.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
CC: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-06 21:08:26 +03:00
Christian Borntraeger
b8cee18cc7 KVM: s390: use yield instead of schedule to implement diag 0x44
diag 0x44 is the common way on s390 to yield the cpu to the hypervisor.
It is called by the guest in cpu_relax and in the spinlock code to
yield to other guest cpus.

This semantic is similar to yield. Lets replace the call to schedule with
yield to make sure that current is really yielding.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-06 21:08:26 +03:00
Christian Borntraeger
0eaeafa10f [S390] s390-kvm: leave sie context on work. Removes preemption requirement
From: Martin Schwidefsky <schwidefsky@de.ibm.com>

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 preemption

Acked-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-05-07 09:23:01 +02:00
Heiko Carstens
484875b11f [S390] Move stfl to system.h and delete duplicated version.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-04-30 13:38:46 +02:00
Marcelo Tosatti
62d9f0dbc9 KVM: add ioctls to save/store mpstate
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 <mtosatti@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27 18:21:16 +03:00
Marcelo Tosatti
3d80840d96 KVM: hlt emulation should take in-kernel APIC/PIT timers into account
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 <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27 12:04:11 +03:00
Avi Kivity
7732a8d19b KVM: s390: Stub out kvmtrace
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27 12:01:20 +03:00
Heiko Carstens
f603f0731f KVM: s390: rename stfl to kvm_stfl
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 <heiko.carstens@de.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27 12:00:59 +03:00
Heiko Carstens
7e8e6ab48d KVM: s390: Fix incorrect return value
kvm_arch_vcpu_ioctl_run currently incorrectly always returns 0.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27 12:00:58 +03:00
Christian Borntraeger
77b455f1bc KVM: s390: add kvm to kconfig on s390
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 <schwidefsky@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27 12:00:47 +03:00
Christian Borntraeger
e28acfea5d KVM: s390: intercepts for diagnose instructions
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 itself

In 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 <martin.schwidefsky@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27 12:00:46 +03:00
Christian Borntraeger
5288fbf0ef KVM: s390: interprocessor communication via sigp
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 cpu

For 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
                     recognized

Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27 12:00:46 +03:00
Christian Borntraeger
453423dce2 KVM: s390: intercepts for privileged instructions
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 topology

Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27 12:00:45 +03:00
Carsten Otte
ba5c1e9b6c KVM: s390: interrupt subsystem, cpu timer, waitpsw
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 processor

struct 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 <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27 12:00:44 +03:00
Christian Borntraeger
8f2abe6a1e KVM: s390: sie intercept handling
This path introduces handling of sie intercepts in three flavors: Intercepts
are either handled completely in-kernel by kvm_handle_sie_intercept(),
or passed to userspace with corresponding data in struct kvm_run in case
kvm_handle_sie_intercept() returns -ENOTSUPP.
In case of partial execution in kernel with the need of userspace support,
kvm_handle_sie_intercept() may choose to set up struct kvm_run and return
-EREMOTE.

The trivial intercept reasons are handled in this patch:
handle_noop() just does nothing for intercepts that don't require our support
  at all
handle_stop() is called when a cpu enters stopped state, and it drops out to
  userland after updating our vcpu state
handle_validity() faults in the cpu lowcore if needed, or passes the request
  to userland

Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27 12:00:43 +03:00
Heiko Carstens
b0c632db63 KVM: s390: arch backend for the kvm kernel module
This patch contains the port of Qumranet's kvm kernel module to IBM zSeries
 (aka s390x, mainframe) architecture. It uses the mainframe's virtualization
instruction SIE to run virtual machines with up to 64 virtual CPUs each.
This port is only usable on 64bit host kernels, and can only run 64bit guest
kernels. However, running 31bit applications in guest userspace is possible.

The following source files are introduced by this patch
arch/s390/kvm/kvm-s390.c    similar to arch/x86/kvm/x86.c, this implements all
                            arch callbacks for kvm. __vcpu_run calls back into
                            sie64a to enter the guest machine context
arch/s390/kvm/sie64a.S      assembler function sie64a, which enters guest
                            context via SIE, and switches world before and after                            that
include/asm-s390/kvm_host.h contains all vital data structures needed to run
                            virtual machines on the mainframe
include/asm-s390/kvm.h      defines kvm_regs and friends for user access to
                            guest register content
arch/s390/kvm/gaccess.h     functions similar to uaccess to access guest memory
arch/s390/kvm/kvm-s390.h    header file for kvm-s390 internals, extended by
                            later patches

Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27 12:00:42 +03:00