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Author SHA1 Message Date
Wanpeng Li ce44a4d5db KVM: Extend MAX_IRQ_ROUTES to 4096 for all archs
[ Upstream commit ddc9cfb79c ]

Our virtual machines make use of device assignment by configuring
12 NVMe disks for high I/O performance. Each NVMe device has 129
MSI-X Table entries:
Capabilities: [50] MSI-X: Enable+ Count=129 Masked-Vector table: BAR=0 offset=00002000
The windows virtual machines fail to boot since they will map the number of
MSI-table entries that the NVMe hardware reported to the bus to msi routing
table, this will exceed the 1024. This patch extends MAX_IRQ_ROUTES to 4096
for all archs, in the future this might be extended again if needed.

Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim KrÄmář <rkrcmar@redhat.com>
Cc: Cornelia Huck <cohuck@redhat.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Tonny Lu <tonnylu@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-21 04:02:57 +09:00
Sebastian Ott 5f95541a0d kvm: fix warning for CONFIG_HAVE_KVM_EVENTFD builds
[ Upstream commit 076467490b ]

Move the kvm_arch_irq_routing_update() prototype outside of
ifdef CONFIG_HAVE_KVM_EVENTFD guards to fix the following sparse warning:

arch/s390/kvm/../../../virt/kvm/irqchip.c:171:28: warning: symbol 'kvm_arch_irq_routing_update' was not declared. Should it be static?

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-30 07:52:02 +02:00
Jan H. Schönherr 40ba283e26 KVM: Let KVM_SET_SIGNAL_MASK work as advertised
[ Upstream commit 20b7035c66 ]

KVM API says for the signal mask you set via KVM_SET_SIGNAL_MASK, that
"any unblocked signal received [...] will cause KVM_RUN to return with
-EINTR" and that "the signal will only be delivered if not blocked by
the original signal mask".

This, however, is only true, when the calling task has a signal handler
registered for a signal. If not, signal evaluation is short-circuited for
SIG_IGN and SIG_DFL, and the signal is either ignored without KVM_RUN
returning or the whole process is terminated.

Make KVM_SET_SIGNAL_MASK behave as advertised by utilizing logic similar
to that in do_sigtimedwait() to avoid short-circuiting of signals.

Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-03 17:39:06 +01:00
Longpeng(Mike) 199b5763d3 KVM: add spinlock optimization framework
If a vcpu exits due to request a user mode spinlock, then
the spinlock-holder may be preempted in user mode or kernel mode.
(Note that not all architectures trap spin loops in user mode,
only AMD x86 and ARM/ARM64 currently do).

But if a vcpu exits in kernel mode, then the holder must be
preempted in kernel mode, so we should choose a vcpu in kernel mode
as a more likely candidate for the lock holder.

This introduces kvm_arch_vcpu_in_kernel() to decide whether the
vcpu is in kernel-mode when it's preempted.  kvm_vcpu_on_spin's
new argument says the same of the spinning VCPU.

Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-08 10:57:43 +02:00
David Hildenbrand 5e2f30b756 KVM: nVMX: get rid of nested_get_page()
nested_get_page() just sounds confusing. All we want is a page from G1.
This is even unrelated to nested.

Let's introduce kvm_vcpu_gpa_to_page() so we don't get too lengthy
lines.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
[Squash pasto fix from Wanpeng Li. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-07 15:27:00 +02:00
Paolo Bonzini 3898da947b KVM: avoid using rcu_dereference_protected
During teardown, accesses to memslots and buses are using
rcu_dereference_protected with an always-true condition because
these accesses are done outside the usual mutexes.  This
is because the last reference is gone and there cannot be any
concurrent modifications, but rcu_dereference_protected is
ugly and unobvious.

Instead, check the refcount in kvm_get_bus and __kvm_memslots.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-08-02 22:41:02 +02:00
Claudio Imbrenda fdeaf7e3eb KVM: make pid available for uevents without debugfs
Simplify and improve the code so that the PID is always available in
the uevent even when debugfs is not available.

This adds a userspace_pid field to struct kvm, as per Radim's
suggestion, so that the PID can be retrieved on destruction too.

Acked-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Fixes: 286de8f6ac ("KVM: trigger uevents when creating or destroying a VM")
Signed-off-by: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-07-26 18:57:44 +02:00
Christian Borntraeger 7e988b103d KVM: use correct accessor function for __kvm_memslots
kvm memslots are protected by srcu and not by rcu. We must use
srcu_dereference_check instead of rcu_dereference_check.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
2017-07-10 12:28:46 +02:00
Christian Borntraeger a80cf7b5f4 KVM: mark memory slots as rcu
we access the memslots array via srcu. Mark it as such and
use the right access functions also for the freeing of
memory slots.

Found by sparse:
./include/linux/kvm_host.h:565:16: error: incompatible types in
comparison expression (different address spaces)

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
2017-07-07 15:24:17 +02:00
Christian Borntraeger 4a12f95177 KVM: mark kvm->busses as rcu protected
mark kvm->busses as rcu protected and use the correct access
function everywhere.

found by sparse
virt/kvm/kvm_main.c:3490:15: error: incompatible types in comparison expression (different address spaces)
virt/kvm/kvm_main.c:3509:15: error: incompatible types in comparison expression (different address spaces)
virt/kvm/kvm_main.c:3561:15: error: incompatible types in comparison expression (different address spaces)
virt/kvm/kvm_main.c:3644:15: error: incompatible types in comparison expression (different address spaces)

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2017-07-07 15:24:16 +02:00
Christian Borntraeger 0e4524a5d3 KVM: mark vcpu->pid pointer as rcu protected
We do use rcu to protect the pid pointer. Mark it as such and
adopt all code to use the proper access methods.

This was detected by sparse.
"virt/kvm/kvm_main.c:2248:15: error: incompatible types in comparison
expression (different address spaces)"

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
2017-07-07 13:00:19 +02:00
Radim Krčmář 2fa6e1e12a KVM: add kvm_request_pending
A first step in vcpu->requests encapsulation.  Additionally, we now
use READ_ONCE() when accessing vcpu->requests, which ensures we
always load vcpu->requests when it's accessed.  This is important as
other threads can change it any time.  Also, READ_ONCE() documents
that vcpu->requests is used with other threads, likely requiring
memory barriers, which it does.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
[ Documented the new use of READ_ONCE() and converted another check
  in arch/mips/kvm/vz.c ]
Signed-off-by: Andrew Jones <drjones@redhat.com>
Acked-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-04 16:53:00 +02:00
Andrew Jones 2387149ead KVM: improve arch vcpu request defining
Marc Zyngier suggested that we define the arch specific VCPU request
base, rather than requiring each arch to remember to start from 8.
That suggestion, along with Radim Krcmar's recent VCPU request flag
addition, snowballed into defining something of an arch VCPU request
defining API.

No functional change.

(Looks like x86 is running out of arch VCPU request bits.  Maybe
 someday we'll need to extend to 64.)

Signed-off-by: Andrew Jones <drjones@redhat.com>
Acked-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-04 16:53:00 +02:00
Linus Torvalds 5ccd414080 Second round of KVM Changes for v4.12:
* ARM: bugfixes; moved shared 32-bit/64-bit files to virt/kvm/arm;
 support for saving/restoring virtual ITS state to userspace
 
 * PPC: XIVE (eXternal Interrupt Virtualization Engine) support
 
 * x86: nVMX improvements, including emulated page modification logging
 (PML) which brings nice performance improvements on some workloads
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull more KVM updates from Paolo Bonzini:
 "ARM:
   - bugfixes
   - moved shared 32-bit/64-bit files to virt/kvm/arm
   - support for saving/restoring virtual ITS state to userspace

  PPC:
   - XIVE (eXternal Interrupt Virtualization Engine) support

  x86:
   - nVMX improvements, including emulated page modification logging
     (PML) which brings nice performance improvements on some workloads"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (45 commits)
  KVM: arm/arm64: vgic-its: Cleanup after failed ITT restore
  KVM: arm/arm64: Don't call map_resources when restoring ITS tables
  KVM: arm/arm64: Register ITS iodev when setting base address
  KVM: arm/arm64: Get rid of its->initialized field
  KVM: arm/arm64: Register iodevs when setting redist base and creating VCPUs
  KVM: arm/arm64: Slightly rework kvm_vgic_addr
  KVM: arm/arm64: Make vgic_v3_check_base more broadly usable
  KVM: arm/arm64: Refactor vgic_register_redist_iodevs
  KVM: Add kvm_vcpu_get_idx to get vcpu index in kvm->vcpus
  nVMX: Advertise PML to L1 hypervisor
  nVMX: Implement emulated Page Modification Logging
  kvm: x86: Add a hook for arch specific dirty logging emulation
  kvm: nVMX: Validate CR3 target count on nested VM-entry
  KVM: set no_llseek in stat_fops_per_vm
  KVM: arm/arm64: vgic: Rename kvm_vgic_vcpu_init to kvm_vgic_vcpu_enable
  KVM: arm/arm64: Clarification and relaxation to ITS save/restore ABI
  KVM: arm64: vgic-v3: KVM_DEV_ARM_VGIC_SAVE_PENDING_TABLES
  KVM: arm64: vgic-its: Fix pending table sync
  KVM: arm64: vgic-its: ITT save and restore
  KVM: arm64: vgic-its: Device table save/restore
  ...
2017-05-10 11:29:23 -07:00
Linus Torvalds de4d195308 Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU updates from Ingo Molnar:
 "The main changes are:

   - Debloat RCU headers

   - Parallelize SRCU callback handling (plus overlapping patches)

   - Improve the performance of Tree SRCU on a CPU-hotplug stress test

   - Documentation updates

   - Miscellaneous fixes"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (74 commits)
  rcu: Open-code the rcu_cblist_n_lazy_cbs() function
  rcu: Open-code the rcu_cblist_n_cbs() function
  rcu: Open-code the rcu_cblist_empty() function
  rcu: Separately compile large rcu_segcblist functions
  srcu: Debloat the <linux/rcu_segcblist.h> header
  srcu: Adjust default auto-expediting holdoff
  srcu: Specify auto-expedite holdoff time
  srcu: Expedite first synchronize_srcu() when idle
  srcu: Expedited grace periods with reduced memory contention
  srcu: Make rcutorture writer stalls print SRCU GP state
  srcu: Exact tracking of srcu_data structures containing callbacks
  srcu: Make SRCU be built by default
  srcu: Fix Kconfig botch when SRCU not selected
  rcu: Make non-preemptive schedule be Tasks RCU quiescent state
  srcu: Expedite srcu_schedule_cbs_snp() callback invocation
  srcu: Parallelize callback handling
  kvm: Move srcu_struct fields to end of struct kvm
  rcu: Fix typo in PER_RCU_NODE_PERIOD header comment
  rcu: Use true/false in assignment to bool
  rcu: Use bool value directly
  ...
2017-05-10 10:30:46 -07:00
Paolo Bonzini 36c344f3f1 Second round of KVM/ARM Changes for v4.12.
Changes include:
  - A fix related to the 32-bit idmap stub
  - A fix to the bitmask used to deode the operands of an AArch32 CP
    instruction
  - We have moved the files shared between arch/arm/kvm and
    arch/arm64/kvm to virt/kvm/arm
  - We add support for saving/restoring the virtual ITS state to
    userspace
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Merge tag 'kvm-arm-for-v4.12-round2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

Second round of KVM/ARM Changes for v4.12.

Changes include:
 - A fix related to the 32-bit idmap stub
 - A fix to the bitmask used to deode the operands of an AArch32 CP
   instruction
 - We have moved the files shared between arch/arm/kvm and
   arch/arm64/kvm to virt/kvm/arm
 - We add support for saving/restoring the virtual ITS state to
   userspace
2017-05-09 12:51:49 +02:00
Christoffer Dall 497d72d80a KVM: Add kvm_vcpu_get_idx to get vcpu index in kvm->vcpus
There are occasional needs to use the index of vcpu in the kvm->vcpus
array to map something related to a VCPU.  For example, unlike the
vcpu->vcpu_id, the vcpu index is guaranteed to not be sparse across all
vcpus which is useful when allocating a memory area for each vcpu.

Signed-off-by: Christoffer Dall <cdall@linaro.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
2017-05-09 12:19:14 +02:00
Paolo Bonzini 4415b33528 Merge branch 'kvm-ppc-next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into HEAD
The main thing here is a new implementation of the in-kernel
XICS interrupt controller emulation for POWER9 machines, from Ben
Herrenschmidt.

POWER9 has a new interrupt controller called XIVE (eXternal Interrupt
Virtualization Engine) which is able to deliver interrupts directly
to guest virtual CPUs in hardware without hypervisor intervention.
With this new code, the guest still sees the old XICS interface but
performance is better because the XICS emulation in the host uses the
XIVE directly rather than going through a XICS emulation in firmware.

Conflicts:
	arch/powerpc/kernel/cpu_setup_power.S [cherry-picked fix]
	arch/powerpc/kvm/book3s_xive.c [include asm/debugfs.h]
2017-05-09 11:50:01 +02:00
Linus Torvalds bf5f89463f Merge branch 'akpm' (patches from Andrew)
Merge more updates from Andrew Morton:

 - the rest of MM

 - various misc things

 - procfs updates

 - lib/ updates

 - checkpatch updates

 - kdump/kexec updates

 - add kvmalloc helpers, use them

 - time helper updates for Y2038 issues. We're almost ready to remove
   current_fs_time() but that awaits a btrfs merge.

 - add tracepoints to DAX

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (114 commits)
  drivers/staging/ccree/ssi_hash.c: fix build with gcc-4.4.4
  selftests/vm: add a test for virtual address range mapping
  dax: add tracepoint to dax_insert_mapping()
  dax: add tracepoint to dax_writeback_one()
  dax: add tracepoints to dax_writeback_mapping_range()
  dax: add tracepoints to dax_load_hole()
  dax: add tracepoints to dax_pfn_mkwrite()
  dax: add tracepoints to dax_iomap_pte_fault()
  mtd: nand: nandsim: convert to memalloc_noreclaim_*()
  treewide: convert PF_MEMALLOC manipulations to new helpers
  mm: introduce memalloc_noreclaim_{save,restore}
  mm: prevent potential recursive reclaim due to clearing PF_MEMALLOC
  mm/huge_memory.c: deposit a pgtable for DAX PMD faults when required
  mm/huge_memory.c: use zap_deposited_table() more
  time: delete CURRENT_TIME_SEC and CURRENT_TIME
  gfs2: replace CURRENT_TIME with current_time
  apparmorfs: replace CURRENT_TIME with current_time()
  lustre: replace CURRENT_TIME macro
  fs: ubifs: replace CURRENT_TIME_SEC with current_time
  fs: ufs: use ktime_get_real_ts64() for birthtime
  ...
2017-05-08 18:17:56 -07:00
Michal Hocko a7c3e901a4 mm: introduce kv[mz]alloc helpers
Patch series "kvmalloc", v5.

There are many open coded kmalloc with vmalloc fallback instances in the
tree.  Most of them are not careful enough or simply do not care about
the underlying semantic of the kmalloc/page allocator which means that
a) some vmalloc fallbacks are basically unreachable because the kmalloc
part will keep retrying until it succeeds b) the page allocator can
invoke a really disruptive steps like the OOM killer to move forward
which doesn't sound appropriate when we consider that the vmalloc
fallback is available.

As it can be seen implementing kvmalloc requires quite an intimate
knowledge if the page allocator and the memory reclaim internals which
strongly suggests that a helper should be implemented in the memory
subsystem proper.

Most callers, I could find, have been converted to use the helper
instead.  This is patch 6.  There are some more relying on __GFP_REPEAT
in the networking stack which I have converted as well and Eric Dumazet
was not opposed [2] to convert them as well.

[1] http://lkml.kernel.org/r/20170130094940.13546-1-mhocko@kernel.org
[2] http://lkml.kernel.org/r/1485273626.16328.301.camel@edumazet-glaptop3.roam.corp.google.com

This patch (of 9):

Using kmalloc with the vmalloc fallback for larger allocations is a
common pattern in the kernel code.  Yet we do not have any common helper
for that and so users have invented their own helpers.  Some of them are
really creative when doing so.  Let's just add kv[mz]alloc and make sure
it is implemented properly.  This implementation makes sure to not make
a large memory pressure for > PAGE_SZE requests (__GFP_NORETRY) and also
to not warn about allocation failures.  This also rules out the OOM
killer as the vmalloc is a more approapriate fallback than a disruptive
user visible action.

This patch also changes some existing users and removes helpers which
are specific for them.  In some cases this is not possible (e.g.
ext4_kvmalloc, libcfs_kvzalloc) because those seems to be broken and
require GFP_NO{FS,IO} context which is not vmalloc compatible in general
(note that the page table allocation is GFP_KERNEL).  Those need to be
fixed separately.

While we are at it, document that __vmalloc{_node} about unsupported gfp
mask because there seems to be a lot of confusion out there.
kvmalloc_node will warn about GFP_KERNEL incompatible (which are not
superset) flags to catch new abusers.  Existing ones would have to die
slowly.

[sfr@canb.auug.org.au: f2fs fixup]
  Link: http://lkml.kernel.org/r/20170320163735.332e64b7@canb.auug.org.au
Link: http://lkml.kernel.org/r/20170306103032.2540-2-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>	[ext4 part]
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-05-08 17:15:12 -07:00
Paolo Bonzini 4e335d9e7d Revert "KVM: Support vCPU-based gfn->hva cache"
This reverts commit bbd6411513.

I've been sitting on this revert for too long and it unfortunately
missed 4.11.  It's also the reason why I haven't merged ring-based
dirty tracking for 4.12.

Using kvm_vcpu_memslots in kvm_gfn_to_hva_cache_init and
kvm_vcpu_write_guest_offset_cached means that the MSR value can
now be used to access SMRAM, simply by making it point to an SMRAM
physical address.  This is problematic because it lets the guest
OS overwrite memory that it shouldn't be able to touch.

Cc: stable@vger.kernel.org
Fixes: bbd6411513
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-05-03 16:30:26 +02:00
David Hildenbrand 5c0aea0e8d KVM: x86: don't hold kvm->lock in KVM_SET_GSI_ROUTING
We needed the lock to avoid racing with creation of the irqchip on x86. As
kvm_set_irq_routing() calls srcu_synchronize_expedited(), this lock
might be held for a longer time.

Let's introduce an arch specific callback to check if we can actually
add irq routes. For x86, all we have to do is check if we have an
irqchip in the kernel. We don't need kvm->lock at that point as the
irqchip is marked as inititalized only when actually fully created.

Reported-by: Steve Rutherford <srutherford@google.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Fixes: 1df6ddede1 ("KVM: x86: race between KVM_SET_GSI_ROUTING and KVM_CREATE_IRQCHIP")
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-05-02 14:45:45 +02:00
Paul Mackerras fb7dcf723d Merge remote-tracking branch 'remotes/powerpc/topic/xive' into kvm-ppc-next
This merges in the powerpc topic/xive branch to bring in the code for
the in-kernel XICS interrupt controller emulation to use the new XIVE
(eXternal Interrupt Virtualization Engine) hardware in the POWER9 chip
directly, rather than via a XICS emulation in firmware.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-04-28 08:23:16 +10:00
Paolo Bonzini 7a97cec26b KVM: mark requests that need synchronization
kvm_make_all_requests() provides a synchronization that waits until all
kicked VCPUs have acknowledged the kick.  This is important for
KVM_REQ_MMU_RELOAD as it prevents freeing while lockless paging is
underway.

This patch adds the synchronization property into all requests that are
currently being used with kvm_make_all_requests() in order to preserve
the current behavior and only introduce a new framework.  Removing it
from requests where it is not necessary is left for future patches.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-04-27 14:36:44 +02:00
Radim Krčmář 178f02ffaf KVM: return if kvm_vcpu_wake_up() did wake up the VCPU
No need to kick a VCPU that we have just woken up.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-04-27 14:18:45 +02:00
Andrew Jones cde9af6e79 KVM: add explicit barrier to kvm_vcpu_kick
kvm_vcpu_kick() must issue a general memory barrier prior to reading
vcpu->mode in order to ensure correctness of the mutual-exclusion
memory barrier pattern used with vcpu->requests.  While the cmpxchg
called from kvm_vcpu_kick():

 kvm_vcpu_kick
   kvm_arch_vcpu_should_kick
     kvm_vcpu_exiting_guest_mode
       cmpxchg

implies general memory barriers before and after the operation, that
implication is only valid when cmpxchg succeeds.  We need an explicit
barrier for when it fails, otherwise a VCPU thread on its entry path
that reads zero for vcpu->requests does not exclude the possibility
the requesting thread sees !IN_GUEST_MODE when it reads vcpu->mode.

kvm_make_all_cpus_request already had a barrier, so we remove it, as
now it would be redundant.

Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-04-27 14:16:17 +02:00
Radim Krčmář 930f7fd6da KVM: mark requests that do not need a wakeup
Some operations must ensure that the guest is not running with stale
data, but if the guest is halted, then the update can wait until another
event happens.  kvm_make_all_requests() currently doesn't wake up, so we
can mark all requests used with it.

First 8 bits were arbitrarily reserved for request numbers.

Most uses of requests have the request type as a constant, so a compiler
will optimize the '&'.

An alternative would be to have an inline function that would return
whether the request needs a wake-up or not, but I like this one better
even though it might produce worse assembly.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-04-27 14:13:57 +02:00
Radim Krčmář 72875d8a4d KVM: add kvm_{test,clear}_request to replace {test,clear}_bit
Users were expected to use kvm_check_request() for testing and clearing,
but request have expanded their use since then and some users want to
only test or do a faster clear.

Make sure that requests are not directly accessed with bit operations.

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-04-27 14:12:22 +02:00
Benjamin Herrenschmidt 5af5099385 KVM: PPC: Book3S HV: Native usage of the XIVE interrupt controller
This patch makes KVM capable of using the XIVE interrupt controller
to provide the standard PAPR "XICS" style hypercalls. It is necessary
for proper operations when the host uses XIVE natively.

This has been lightly tested on an actual system, including PCI
pass-through with a TG3 device.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[mpe: Cleanup pr_xxx(), unsplit pr_xxx() strings, etc., fix build
 failures by adding KVM_XIVE which depends on KVM_XICS and XIVE, and
 adding empty stubs for the kvm_xive_xxx() routines, fixup subject,
 integrate fixes from Paul for building PR=y HV=n]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-04-27 21:37:29 +10:00
Ingo Molnar 58d30c36d4 Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
Pull RCU updates from Paul E. McKenney:

 - Documentation updates.

 - Miscellaneous fixes.

 - Parallelize SRCU callback handling (plus overlapping patches).

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-04-23 11:12:44 +02:00
Paul E. McKenney 6ade8694f4 kvm: Move srcu_struct fields to end of struct kvm
Parallelizing SRCU callback handling will increase the size of
srcu_struct, which will move the kvm structure's kvm_arch field out
of reach of powerpc's current assembly code, which will result in the
following sort of build error:

arch/powerpc/kvm/book3s_hv_rmhandlers.S:617: Error: operand out of range (0x000000000000b328 is not between 0xffffffffffff8000 and 0x0000000000007fff)

This commit moves the srcu_struct fields in the kvm structure to follow
the kvm_arch field, which will allow powerpc's assembly code to continue
to be able to reach the kvm_arch field.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: Michael Ellerman <michaele@au1.ibm.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
[ paulmck: Moved this commit to precede SRCU callback parallelization,
  and reworded the commit log into future tense, all in the name of
  bisectability. ]
2017-04-21 05:56:31 -07:00
David Hildenbrand 993225adf4 KVM: x86: rename kvm_vcpu_request_scan_ioapic()
Let's rename it into a proper arch specific callback.

Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-04-12 20:17:14 +02:00
Paolo Bonzini 4b4357e025 kvm: make KVM_COALESCED_MMIO_PAGE_OFFSET public
Its value has never changed; we might as well make it part of the ABI instead
of using the return value of KVM_CHECK_EXTENSION(KVM_CAP_COALESCED_MMIO).

Because PPC does not always make MMIO available, the code has to be made
dependent on CONFIG_KVM_MMIO rather than KVM_COALESCED_MMIO_PAGE_OFFSET.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-04-07 16:49:01 +02:00
Paolo Bonzini ad6260da1e KVM: x86: drop legacy device assignment
Legacy device assignment has been deprecated since 4.2 (released
1.5 years ago).  VFIO is better and everyone should have switched to it.
If they haven't, this should convince them. :)

Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-04-07 16:49:00 +02:00
David Hildenbrand 90db10434b KVM: kvm_io_bus_unregister_dev() should never fail
No caller currently checks the return value of
kvm_io_bus_unregister_dev(). This is evil, as all callers silently go on
freeing their device. A stale reference will remain in the io_bus,
getting at least used again, when the iobus gets teared down on
kvm_destroy_vm() - leading to use after free errors.

There is nothing the callers could do, except retrying over and over
again.

So let's simply remove the bus altogether, print an error and make
sure no one can access this broken bus again (returning -ENOMEM on any
attempt to access it).

Fixes: e93f8a0f82 ("KVM: convert io_bus to SRCU")
Cc: stable@vger.kernel.org # 3.4+
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-03-23 19:02:25 +01:00
Elena Reshetova e3736c3eb3 kvm: convert kvm.users_count from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-03-01 17:03:21 +01:00
Paolo Bonzini bd7e5b0899 KVM: x86: remove code for lazy FPU handling
The FPU is always active now when running KVM.

Reviewed-by: David Matlack <dmatlack@google.com>
Reviewed-by: Bandan Das <bsd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-02-17 12:28:01 +01:00
Cao, Lei bbd6411513 KVM: Support vCPU-based gfn->hva cache
Provide versions of struct gfn_to_hva_cache functions that
take vcpu as a parameter instead of struct kvm.  The existing functions
are not needed anymore, so delete them.  This allows dirty pages to
be logged in the vcpu dirty ring, instead of the global dirty ring,
for ring-based dirty memory tracking.

Signed-off-by: Lei Cao <lei.cao@stratus.com>
Message-Id: <CY1PR08MB19929BD2AC47A291FD680E83F04F0@CY1PR08MB1992.namprd08.prod.outlook.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-02-16 18:42:46 +01:00
Marc Zyngier 9d93dc1c96 arm/arm64: KVM: Get rid of KVM_MEMSLOT_INCOHERENT
KVM_MEMSLOT_INCOHERENT is not used anymore, as we've killed its
only use in the arm/arm64 MMU code. Let's remove the last artifacts.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-01-30 13:47:38 +00:00
Linus Torvalds 93173b5bf2 Small release, the most interesting stuff is x86 nested virt improvements.
x86: userspace can now hide nested VMX features from guests; nested
 VMX can now run Hyper-V in a guest; support for AVX512_4VNNIW and
 AVX512_FMAPS in KVM; infrastructure support for virtual Intel GPUs.
 
 PPC: support for KVM guests on POWER9; improved support for interrupt
 polling; optimizations and cleanups.
 
 s390: two small optimizations, more stuff is in flight and will be
 in 4.11.
 
 ARM: support for the GICv3 ITS on 32bit platforms.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Paolo Bonzini:
 "Small release, the most interesting stuff is x86 nested virt
  improvements.

  x86:
   - userspace can now hide nested VMX features from guests
   - nested VMX can now run Hyper-V in a guest
   - support for AVX512_4VNNIW and AVX512_FMAPS in KVM
   - infrastructure support for virtual Intel GPUs.

  PPC:
   - support for KVM guests on POWER9
   - improved support for interrupt polling
   - optimizations and cleanups.

  s390:
   - two small optimizations, more stuff is in flight and will be in
     4.11.

  ARM:
   - support for the GICv3 ITS on 32bit platforms"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (94 commits)
  arm64: KVM: pmu: Reset PMSELR_EL0.SEL to a sane value before entering the guest
  KVM: arm/arm64: timer: Check for properly initialized timer on init
  KVM: arm/arm64: vgic-v2: Limit ITARGETSR bits to number of VCPUs
  KVM: x86: Handle the kthread worker using the new API
  KVM: nVMX: invvpid handling improvements
  KVM: nVMX: check host CR3 on vmentry and vmexit
  KVM: nVMX: introduce nested_vmx_load_cr3 and call it on vmentry
  KVM: nVMX: propagate errors from prepare_vmcs02
  KVM: nVMX: fix CR3 load if L2 uses PAE paging and EPT
  KVM: nVMX: load GUEST_EFER after GUEST_CR0 during emulated VM-entry
  KVM: nVMX: generate MSR_IA32_CR{0,4}_FIXED1 from guest CPUID
  KVM: nVMX: fix checks on CR{0,4} during virtual VMX operation
  KVM: nVMX: support restore of VMX capability MSRs
  KVM: nVMX: generate non-true VMX MSRs based on true versions
  KVM: x86: Do not clear RFLAGS.TF when a singlestep trap occurs.
  KVM: x86: Add kvm_skip_emulated_instruction and use it.
  KVM: VMX: Move skip_emulated_instruction out of nested_vmx_check_vmcs12
  KVM: VMX: Reorder some skip_emulated_instruction calls
  KVM: x86: Add a return value to kvm_emulate_cpuid
  KVM: PPC: Book3S: Move prototypes for KVM functions into kvm_ppc.h
  ...
2016-12-13 15:47:02 -08:00
Linus Torvalds 518bacf5a5 Merge branch 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 FPU updates from Ingo Molnar:
 "The main changes in this cycle were:

   - do a large round of simplifications after all CPUs do 'eager' FPU
     context switching in v4.9: remove CR0 twiddling, remove leftover
     eager/lazy bts, etc (Andy Lutomirski)

   - more FPU code simplifications: remove struct fpu::counter, clarify
     nomenclature, remove unnecessary arguments/functions and better
     structure the code (Rik van Riel)"

* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/fpu: Remove clts()
  x86/fpu: Remove stts()
  x86/fpu: Handle #NM without FPU emulation as an error
  x86/fpu, lguest: Remove CR0.TS support
  x86/fpu, kvm: Remove host CR0.TS manipulation
  x86/fpu: Remove irq_ts_save() and irq_ts_restore()
  x86/fpu: Stop saving and restoring CR0.TS in fpu__init_check_bugs()
  x86/fpu: Get rid of two redundant clts() calls
  x86/fpu: Finish excising 'eagerfpu'
  x86/fpu: Split old_fpu & new_fpu handling into separate functions
  x86/fpu: Remove 'cpu' argument from __cpu_invalidate_fpregs_state()
  x86/fpu: Split old & new FPU code paths
  x86/fpu: Remove __fpregs_(de)activate()
  x86/fpu: Rename lazy restore functions to "register state valid"
  x86/fpu, kvm: Remove KVM vcpu->fpu_counter
  x86/fpu: Remove struct fpu::counter
  x86/fpu: Remove use_eager_fpu()
  x86/fpu: Remove the XFEATURE_MASK_EAGER/LAZY distinction
  x86/fpu: Hard-disable lazy FPU mode
  x86/crypto, x86/fpu: Remove X86_FEATURE_EAGER_FPU #ifdef from the crc32c code
2016-12-12 14:27:49 -08:00
Radim Krčmář ffcb09f27f Merge branch 'kvm-ppc-next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
PPC KVM update for 4.10:

 * Support for KVM guests on POWER9 using the hashed page table MMU.
 * Updates and improvements to the halt-polling support on PPC, from
   Suraj Jitindar Singh.
 * An optimization to speed up emulated MMIO, from Yongji Xie.
 * Various other minor cleanups.
2016-11-29 14:26:55 +01:00
Suraj Jitindar Singh ec76d819d2 KVM: Export kvm module parameter variables
The kvm module has the parameters halt_poll_ns, halt_poll_ns_grow, and
halt_poll_ns_shrink. Halt polling was recently added to the powerpc kvm-hv
module and these parameters were essentially duplicated for that. There is
no benefit to this duplication and it can lead to confusion when trying to
tune halt polling.

Thus move the definition of these variables to kvm_host.h and export them.
This will allow the kvm-hv module to use the same module parameters by
accessing these variables, which will be implemented in the next patch,
meaning that they will no longer be duplicated.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2016-11-28 11:48:47 +11:00
Bandan Das ae0f549951 kvm: x86: don't print warning messages for unimplemented msrs
Change unimplemented msrs messages to use pr_debug.
If CONFIG_DYNAMIC_DEBUG is set, then these messages can be
enabled at run time or else -DDEBUG can be used at compile
time to enable them. These messages will still be printed if
ignore_msrs=1.

Signed-off-by: Bandan Das <bsd@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-11-22 18:29:10 +01:00
Pan Xinhui 4ec6e86362 kvm: Introduce kvm_write_guest_offset_cached()
It allows us to update some status or field of a structure partially.

We can also save a kvm_read_guest_cached() call if we just update one
fild of the struct regardless of its current value.

Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: David.Laight@ACULAB.COM
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: benh@kernel.crashing.org
Cc: boqun.feng@gmail.com
Cc: borntraeger@de.ibm.com
Cc: bsingharora@gmail.com
Cc: dave@stgolabs.net
Cc: jgross@suse.com
Cc: kernellwp@gmail.com
Cc: konrad.wilk@oracle.com
Cc: linuxppc-dev@lists.ozlabs.org
Cc: mpe@ellerman.id.au
Cc: paulmck@linux.vnet.ibm.com
Cc: paulus@samba.org
Cc: rkrcmar@redhat.com
Cc: virtualization@lists.linux-foundation.org
Cc: will.deacon@arm.com
Cc: xen-devel-request@lists.xenproject.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1478077718-37424-8-git-send-email-xinhui.pan@linux.vnet.ibm.com
[ Typo fixes. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-11-22 12:48:07 +01:00
Ingo Molnar 4d69f155d5 Linux 4.9-rc1
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Merge tag 'v4.9-rc1' into x86/fpu, to resolve conflict

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-16 13:04:34 +02:00
Rik van Riel 3d42de25d2 x86/fpu, kvm: Remove KVM vcpu->fpu_counter
With the removal of the lazy FPU code, this field is no longer used.
Get rid of it.

Signed-off-by: Rik van Riel <riel@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: pbonzini@redhat.com
Link: http://lkml.kernel.org/r/1475627678-20788-7-git-send-email-riel@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-07 11:14:41 +02:00
Luiz Capitulino 45b5939e50 kvm: create per-vcpu dirs in debugfs
This commit adds the ability for archs to export
per-vcpu information via a new per-vcpu dir in
the VM's debugfs directory.

If kvm_arch_has_vcpu_debugfs() returns true, then KVM
will create a vcpu dir for each vCPU in the VM's
debugfs directory. Then kvm_arch_create_vcpu_debugfs()
is responsible for populating each vcpu directory
with arch specific entries.

The per-vcpu path in debugfs will look like:

/sys/kernel/debug/kvm/29162-10/vcpu0
/sys/kernel/debug/kvm/29162-10/vcpu1

This is all arch specific for now because the only
user of this interface (x86) wants to export x86-specific
per-vcpu information to user-space.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-09-16 16:57:47 +02:00
Luiz Capitulino 235539b48a kvm: add stubs for arch specific debugfs support
Two stubs are added:

 o kvm_arch_has_vcpu_debugfs(): must return true if the arch
   supports creating debugfs entries in the vcpu debugfs dir
   (which will be implemented by the next commit)

 o kvm_arch_create_vcpu_debugfs(): code that creates debugfs
   entries in the vcpu debugfs dir

For x86, this commit introduces a new file to avoid growing
arch/x86/kvm/x86.c even more.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-09-16 16:57:47 +02:00
Christoffer Dall a28ebea2ad KVM: Protect device ops->create and list_add with kvm->lock
KVM devices were manipulating list data structures without any form of
synchronization, and some implementations of the create operations also
suffered from a lack of synchronization.

Now when we've split the xics create operation into create and init, we
can hold the kvm->lock mutex while calling the create operation and when
manipulating the devices list.

The error path in the generic code gets slightly ugly because we have to
take the mutex again and delete the device from the list, but holding
the mutex during anon_inode_getfd or releasing/locking the mutex in the
common non-error path seemed wrong.

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-08-12 12:01:27 +02:00