Andrey Smetanin [Mon, 30 Nov 2015 16:22:21 +0000 (19:22 +0300)]
kvm/x86: Hyper-V SynIC timers
Per Hyper-V specification (and as required by Hyper-V-aware guests),
SynIC provides 4 per-vCPU timers. Each timer is programmed via a pair
of MSRs, and signals expiration by delivering a special format message
to the configured SynIC message slot and triggering the corresponding
synthetic interrupt.
Note: as implemented by this patch, all periodic timers are "lazy"
(i.e. if the vCPU wasn't scheduled for more than the timer period the
timer events are lost), regardless of the corresponding configuration
MSR. If deemed necessary, the "catch up" mode (the timer period is
shortened until the timer catches up) will be implemented later.
Changes v2:
* Use remainder to calculate periodic timer expiration time
Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com> Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> CC: Gleb Natapov <gleb@kernel.org> CC: Paolo Bonzini <pbonzini@redhat.com> CC: "K. Y. Srinivasan" <kys@microsoft.com> CC: Haiyang Zhang <haiyangz@microsoft.com> CC: Vitaly Kuznetsov <vkuznets@redhat.com> CC: Roman Kagan <rkagan@virtuozzo.com> CC: Denis V. Lunev <den@openvz.org> CC: qemu-devel@nongnu.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Andrey Smetanin [Mon, 30 Nov 2015 16:22:20 +0000 (19:22 +0300)]
kvm/x86: Hyper-V SynIC message slot pending clearing at SINT ack
The SynIC message protocol mandates that the message slot is claimed
by atomically setting message type to something other than HVMSG_NONE.
If another message is to be delivered while the slot is still busy,
message pending flag is asserted to indicate to the guest that the
hypervisor wants to be notified when the slot is released.
To make sure the protocol works regardless of where the message
sources are (kernel or userspace), clear the pending flag on SINT ACK
notification, and let the message sources compete for the slot again.
Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com> Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> CC: Gleb Natapov <gleb@kernel.org> CC: Paolo Bonzini <pbonzini@redhat.com> CC: "K. Y. Srinivasan" <kys@microsoft.com> CC: Haiyang Zhang <haiyangz@microsoft.com> CC: Vitaly Kuznetsov <vkuznets@redhat.com> CC: Roman Kagan <rkagan@virtuozzo.com> CC: Denis V. Lunev <den@openvz.org> CC: qemu-devel@nongnu.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Andrey Smetanin [Mon, 30 Nov 2015 16:22:16 +0000 (19:22 +0300)]
drivers/hv: Move struct hv_timer_message_payload into UAPI Hyper-V x86 header
This struct is required for Hyper-V SynIC timers implementation inside KVM
and for upcoming Hyper-V VMBus support by userspace(QEMU). So place it into
Hyper-V UAPI header.
Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com> CC: Gleb Natapov <gleb@kernel.org> CC: Paolo Bonzini <pbonzini@redhat.com> CC: "K. Y. Srinivasan" <kys@microsoft.com> CC: Haiyang Zhang <haiyangz@microsoft.com> CC: Vitaly Kuznetsov <vkuznets@redhat.com> CC: Roman Kagan <rkagan@virtuozzo.com> CC: Denis V. Lunev <den@openvz.org> CC: qemu-devel@nongnu.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Andrey Smetanin [Mon, 30 Nov 2015 16:22:15 +0000 (19:22 +0300)]
drivers/hv: Move struct hv_message into UAPI Hyper-V x86 header
This struct is required for Hyper-V SynIC timers implementation inside KVM
and for upcoming Hyper-V VMBus support by userspace(QEMU). So place it into
Hyper-V UAPI header.
Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com> Acked-by: K. Y. Srinivasan <kys@microsoft.com> Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> CC: Gleb Natapov <gleb@kernel.org> CC: Paolo Bonzini <pbonzini@redhat.com> CC: "K. Y. Srinivasan" <kys@microsoft.com> CC: Haiyang Zhang <haiyangz@microsoft.com> CC: Vitaly Kuznetsov <vkuznets@redhat.com> CC: Roman Kagan <rkagan@virtuozzo.com> CC: Denis V. Lunev <den@openvz.org> CC: qemu-devel@nongnu.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Wed, 16 Dec 2015 17:49:29 +0000 (18:49 +0100)]
Merge tag 'kvm-s390-next-4.5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD
KVM: s390 features and fixes for 4.5 (kvm/next)
Some small cleanups
- use assignment instead of memcpy
- use %pK for kernel pointers
Changes regarding guest memory size
- Fix an off-by-one error in our guest memory interface (we might
use unnecessarily big page tables, e.g. 3 levels for a 2GB guest
instead of 2 levels)
- We now ask the machine about the max. supported guest address
and limit accordingly.
Dominik Dingel [Mon, 1 Dec 2014 16:24:42 +0000 (17:24 +0100)]
KVM: s390: fix mismatch between user and in-kernel guest limit
While the userspace interface requests the maximum size the gmap code
expects to get a maximum address.
This error resulted in bigger page tables than necessary for some guest
sizes, e.g. a 2GB guest used 3 levels instead of 2.
At the same time we introduce KVM_S390_NO_MEM_LIMIT, which allows in a
bright future that a guest spans the complete 64 bit address space.
We also switch to TASK_MAX_SIZE for the initial memory size, this is a
cosmetic change as the previous size also resulted in a 4 level pagetable
creation.
Reported-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
The s390dbf and trace events provide a debugfs interface.
If kptr_restrict is active, we should not expose kernel
pointers. We can fence the debugfs output by using %pK
instead of %p.
KVM: s390: don't load kvm without virtualization support
If we don't have support for virtualization (SIE), e.g. when running under
a hypervisor not supporting execution of the SIE instruction, we should
immediately abort loading the kvm module, as the SIE instruction cannot
be enabled dynamically.
Currently, the SIE instructions fails with an exception on a non-SIE
host, resulting in the guest making no progress, instead of failing hard.
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
s390: show virtualization support in /proc/cpuinfo
This patch exposes the SIE capability (aka virtualization support) via
/proc/cpuinfo -> "features" as "sie".
As we don't want to expose this hwcap via elf, let's add a second,
"internal"/non-elf capability list. The content is simply concatenated
to the existing features when printing /proc/cpuinfo.
We also add the defines to elf.h to keep the hwcap stuff at a common
place.
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
sca_add_vpcu is not called for ucontrol guests. We must also not
apply the sca checking for sca_can_add_vcpu as ucontrol guests
do not have to follow the sca limits.
As common code already checks that id < KVM_MAX_VCPUS all other
data structures are safe as well.
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Let's always set and clear the sda when enabling/disabling a VCPU.
Dealing with sda being set to something else makes no sense anymore
as we enable a VCPU in the SCA now after it has been registered at
the VM.
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
If something goes wrong in kvm_arch_vcpu_create, the VCPU has already
been added to the sca but will never be removed. Trying to create VCPUs
with duplicate ids (e.g. after a failed attempt) is problematic.
Also, when creating multiple VCPUs in parallel, we could theoretically
forget to set the correct SCA when the switch to ESCA happens just
before the VCPU is registered.
Let's add the VCPU to the SCA in kvm_arch_vcpu_postcreate, where we can
be sure that no duplicate VCPU with the same id is around and the VCPU
has already been registered at the VM. We also have to make sure to update
ECB at that point.
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Having no sca can never happen, even when something goes wrong when
switching to ESCA. Otherwise we would have a serious bug.
Let's remove this superfluous check.
Acked-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
If CPUSTAT_ECALL_PEND isn't set, we can't have an external call pending,
so we can directly avoid taking the lock.
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
This patch allows s390 to have more than 64 VCPUs for a guest (up to
248 for memory usage considerations), if supported by the underlaying
hardware (sclp.has_esca).
Signed-off-by: Eugene (jno) Dvurechenski <jno@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
This patch adds code that performs transparent switch to Extended
SCA on addition of 65th VCPU in a VM. Disposal of ESCA is added too.
The entier ESCA functionality, however, is still not enabled.
The enablement will be provided in a separate patch.
This patch also uses read/write lock protection of SCA and its subfields for
possible disposal at the BSCA-to-ESCA transition. While only Basic SCA needs such
a protection (for the swap), any SCA access is now guarded.
Signed-off-by: Eugene (jno) Dvurechenski <jno@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
This patch updates the routines (sca_*) to provide transparent access
to and manipulation on the data for both Basic and Extended SCA in use.
The kvm.arch.sca is generalized to (void *) to handle BSCA/ESCA cases.
Also the kvm.arch.use_esca flag is provided.
The actual functionality is kept the same.
Signed-off-by: Eugene (jno) Dvurechenski <jno@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
KVM: s390: rewrite vcpu_post_run and drop out early
Let's rewrite this function to better reflect how we actually handle
exit_code. By dropping out early we can save a few cycles. This
especially speeds up sie exits caused by host irqs.
Also, let's move the special -EOPNOTSUPP for intercepts to
the place where it belongs and convert it to -EREMOTE.
Reviewed-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Janosch Frank [Wed, 14 Oct 2015 10:37:35 +0000 (12:37 +0200)]
KVM: Remove unnecessary debugfs dentry references
KVM creates debugfs files to export VM statistics to userland. To be
able to remove them on kvm exit it tracks the files' dentries.
Since their parent directory is also tracked and since each parent
direntry knows its children we can easily remove them by using
debugfs_remove_recursive(kvm_debugfs_dir). Therefore we don't
need the extra tracking in the kvm_stats_debugfs_item anymore.
Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com> Reviewed-By: Sascha Silbe <silbe@linux.vnet.ibm.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Usually, VCPU ids match the array index. So let's try a fast
lookup first before falling back to the slow iteration.
Suggested-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Let's reuse the new common function for VPCU lookup by id.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
[split out the new function into a separate patch]
Takuya Yoshikawa [Thu, 26 Nov 2015 12:15:38 +0000 (21:15 +0900)]
KVM: x86: MMU: Use for_each_rmap_spte macro instead of pte_list_walk()
As kvm_mmu_get_page() was changed so that every parent pointer would not
get into the sp->parent_ptes chain before the entry pointed to by it was
set properly, we can use the for_each_rmap_spte macro instead of
pte_list_walk().
Takuya Yoshikawa [Thu, 26 Nov 2015 12:14:34 +0000 (21:14 +0900)]
KVM: x86: MMU: Move parent_pte handling from kvm_mmu_get_page() to link_shadow_page()
Every time kvm_mmu_get_page() is called with a non-NULL parent_pte
argument, link_shadow_page() follows that to set the parent entry so
that the new mapping will point to the returned page table.
Moving parent_pte handling there allows to clean up the code because
parent_pte is passed to kvm_mmu_get_page() just for mark_unsync() and
mmu_page_add_parent_pte().
In addition, the patch avoids calling mark_unsync() for other parents in
the sp->parent_ptes chain than the newly added parent_pte, because they
have been there since before the current page fault handling started.
Takuya Yoshikawa [Fri, 20 Nov 2015 08:46:29 +0000 (17:46 +0900)]
KVM: x86: MMU: Move initialization of parent_ptes out from kvm_mmu_alloc_page()
Make kvm_mmu_alloc_page() do just what its name tells to do, and remove
the extra allocation error check and zero-initialization of parent_ptes:
shadow page headers allocated by kmem_cache_zalloc() are always in the
per-VCPU pools.
Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Takuya Yoshikawa [Fri, 20 Nov 2015 08:45:44 +0000 (17:45 +0900)]
KVM: x86: MMU: Consolidate BUG_ON checks for reverse-mapped sptes
At some call sites of rmap_get_first() and rmap_get_next(), BUG_ON is
placed right after the call to detect unrelated sptes which must not be
found in the reverse-mapping list.
Move this check in rmap_get_first/next() so that all call sites, not
just the users of the for_each_rmap_spte() macro, will be checked the
same way.
One thing to keep in mind is that kvm_mmu_unlink_parents() also uses
rmap_get_first() to handle parent sptes. The change will not break it
because parent sptes are present, at least until drop_parent_pte()
actually unlinks them, and not mmio-sptes.
Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Takuya Yoshikawa [Fri, 20 Nov 2015 08:44:55 +0000 (17:44 +0900)]
KVM: x86: MMU: Remove is_rmap_spte() and use is_shadow_present_pte()
is_rmap_spte(), originally named is_rmap_pte(), was introduced when the
simple reverse mapping was implemented by commit cd4a4e5374110444
("[PATCH] KVM: MMU: Implement simple reverse mapping"). At that point,
its role was clear and only rmap_add() and rmap_remove() were using it
to select sptes that need to be reverse-mapped.
Independently of that, is_shadow_present_pte() was first introduced by
commit c7addb902054195b ("KVM: Allow not-present guest page faults to
bypass kvm") to do bypass_guest_pf optimization, which does not exist
any more.
These two seem to have changed their roles somewhat, and is_rmap_spte()
just calls is_shadow_present_pte() now.
Since using both of them without clear distinction just makes the code
confusing, remove is_rmap_spte().
Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Takuya Yoshikawa [Fri, 20 Nov 2015 08:44:05 +0000 (17:44 +0900)]
KVM: x86: MMU: Make mmu_set_spte() return emulate value
mmu_set_spte()'s code is based on the assumption that the emulate
parameter has a valid pointer value if set_spte() returns true and
write_fault is not zero. In other cases, emulate may be NULL, so a
NULL-check is needed.
Stop passing emulate pointer and make mmu_set_spte() return the emulate
value instead to clean up this complex interface. Prefetch functions
can just throw away the return value.
Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Takuya Yoshikawa [Fri, 20 Nov 2015 08:43:13 +0000 (17:43 +0900)]
KVM: x86: MMU: Add helper function to clear a bit in unsync child bitmap
Both __mmu_unsync_walk() and mmu_pages_clear_parents() have three line
code which clears a bit in the unsync child bitmap; the former places it
inside a loop block and uses a few goto statements to jump to it.
A new helper function, clear_unsync_child_bit(), makes the code cleaner.
Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Yaowei Bai [Mon, 16 Nov 2015 03:10:24 +0000 (11:10 +0800)]
KVM: powerpc: kvmppc_visible_gpa can be boolean
In another patch kvm_is_visible_gfn is maken return bool due to this
function only returns zero or one as its return value, let's also make
kvmppc_visible_gpa return bool to keep consistent.
No functional change.
Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Since nEPT doesn't support A/D bit, we should not set those bit
when building the shadow page table.
but this is not necessary. Even though nEPT doesn't support A/D
bits, and hence the vmcs12 EPT pointer will never enable them,
we always use them for shadow page tables if available (see
construct_eptp in vmx.c). So we can set the A/D bits freely
in the shadow page table.
This patch hence basically reverts commit 7a1638ce4220.
Cc: Yang Zhang <yang.z.zhang@Intel.com> Cc: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Thu, 12 Nov 2015 13:49:16 +0000 (14:49 +0100)]
KVM: svm: add support for RDTSCP
RDTSCP was never supported for AMD CPUs, which nobody noticed because
Linux does not use it. But exactly the fact that Linux does not
use it makes the implementation very simple; we can freely trash
MSR_TSC_AUX while running the guest.
Cc: Joerg Roedel <joro@8bytes.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Thu, 12 Nov 2015 13:49:17 +0000 (14:49 +0100)]
KVM: x86: expose MSR_TSC_AUX to userspace
If we do not do this, it is not properly saved and restored across
migration. Windows notices due to its self-protection mechanisms,
and is very upset about it (blue screen of death).
Cc: Radim Krcmar <rkrcmar@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Andrey Smetanin [Tue, 10 Nov 2015 12:36:35 +0000 (15:36 +0300)]
kvm/x86: Hyper-V kvm exit
A new vcpu exit is introduced to notify the userspace of the
changes in Hyper-V SynIC configuration triggered by guest writing to the
corresponding MSRs.
Changes v4:
* exit into userspace only if guest writes into SynIC MSR's
Changes v3:
* added KVM_EXIT_HYPERV types and structs notes into docs
Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com> Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Gleb Natapov <gleb@kernel.org> CC: Paolo Bonzini <pbonzini@redhat.com> CC: Roman Kagan <rkagan@virtuozzo.com> CC: Denis V. Lunev <den@openvz.org> CC: qemu-devel@nongnu.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Andrey Smetanin [Tue, 10 Nov 2015 12:36:34 +0000 (15:36 +0300)]
kvm/x86: Hyper-V synthetic interrupt controller
SynIC (synthetic interrupt controller) is a lapic extension,
which is controlled via MSRs and maintains for each vCPU
- 16 synthetic interrupt "lines" (SINT's); each can be configured to
trigger a specific interrupt vector optionally with auto-EOI
semantics
- a message page in the guest memory with 16 256-byte per-SINT message
slots
- an event flag page in the guest memory with 16 2048-bit per-SINT
event flag areas
The host triggers a SINT whenever it delivers a new message to the
corresponding slot or flips an event flag bit in the corresponding area.
The guest informs the host that it can try delivering a message by
explicitly asserting EOI in lapic or writing to End-Of-Message (EOM)
MSR.
The userspace (qemu) triggers interrupts and receives EOM notifications
via irqfd with resampler; for that, a GSI is allocated for each
configured SINT, and irq_routing api is extended to support GSI-SINT
mapping.
Changes v4:
* added activation of SynIC by vcpu KVM_ENABLE_CAP
* added per SynIC active flag
* added deactivation of APICv upon SynIC activation
Changes v3:
* added KVM_CAP_HYPERV_SYNIC and KVM_IRQ_ROUTING_HV_SINT notes into
docs
Changes v2:
* do not use posted interrupts for Hyper-V SynIC AutoEOI vectors
* add Hyper-V SynIC vectors into EOI exit bitmap
* Hyper-V SyniIC SINT msr write logic simplified
Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com> Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Gleb Natapov <gleb@kernel.org> CC: Paolo Bonzini <pbonzini@redhat.com> CC: Roman Kagan <rkagan@virtuozzo.com> CC: Denis V. Lunev <den@openvz.org> CC: qemu-devel@nongnu.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Andrey Smetanin [Tue, 10 Nov 2015 12:36:33 +0000 (15:36 +0300)]
kvm/x86: per-vcpu apicv deactivation support
The decision on whether to use hardware APIC virtualization used to be
taken globally, based on the availability of the feature in the CPU
and the value of a module parameter.
However, under certain circumstances we want to control it on per-vcpu
basis. In particular, when the userspace activates HyperV synthetic
interrupt controller (SynIC), APICv has to be disabled as it's
incompatible with SynIC auto-EOI behavior.
To achieve that, introduce 'apicv_active' flag on struct
kvm_vcpu_arch, and kvm_vcpu_deactivate_apicv() function to turn APICv
off. The flag is initialized based on the module parameter and CPU
capability, and consulted whenever an APICv-specific action is
performed.
Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com> Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Gleb Natapov <gleb@kernel.org> CC: Paolo Bonzini <pbonzini@redhat.com> CC: Roman Kagan <rkagan@virtuozzo.com> CC: Denis V. Lunev <den@openvz.org> CC: qemu-devel@nongnu.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Andrey Smetanin [Tue, 10 Nov 2015 12:36:32 +0000 (15:36 +0300)]
kvm/x86: split ioapic-handled and EOI exit bitmaps
The function to determine if the vector is handled by ioapic used to
rely on the fact that only ioapic-handled vectors were set up to
cause vmexits when virtual apic was in use.
We're going to break this assumption when introducing Hyper-V
synthetic interrupts: they may need to cause vmexits too.
To achieve that, introduce a new bitmap dedicated specifically for
ioapic-handled vectors, and populate EOI exit bitmap from it for now.
Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com> Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Gleb Natapov <gleb@kernel.org> CC: Paolo Bonzini <pbonzini@redhat.com> CC: Roman Kagan <rkagan@virtuozzo.com> CC: Denis V. Lunev <den@openvz.org> CC: qemu-devel@nongnu.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Actually kvm_arch_irq_routing_update() should be
kvm_arch_post_irq_routing_update() as it's called at the end
of irq routing update.
This renaming frees kvm_arch_irq_routing_update function name.
kvm_arch_irq_routing_update() weak function which will be used
to update mappings for arch-specific irq routing entries
(in particular, the upcoming Hyper-V synthetic interrupts).
Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com> Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Gleb Natapov <gleb@kernel.org> CC: Paolo Bonzini <pbonzini@redhat.com> CC: Roman Kagan <rkagan@virtuozzo.com> CC: Denis V. Lunev <den@openvz.org> CC: qemu-devel@nongnu.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Haozhong Zhang [Wed, 25 Nov 2015 09:21:39 +0000 (17:21 +0800)]
KVM: nVMX: remove incorrect vpid check in nested invvpid emulation
This patch removes the vpid check when emulating nested invvpid
instruction of type all-contexts invalidation. The existing code is
incorrect because:
(1) According to Intel SDM Vol 3, Section "INVVPID - Invalidate
Translations Based on VPID", invvpid instruction does not check
vpid in the invvpid descriptor when its type is all-contexts
invalidation.
(2) According to the same document, invvpid of type all-contexts
invalidation does not require there is an active VMCS, so/and
get_vmcs12() in the existing code may result in a NULL-pointer
dereference. In practice, it can crash both KVM itself and L1
hypervisors that use invvpid (e.g. Xen).
Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Mark Rutland [Mon, 16 Nov 2015 13:58:29 +0000 (13:58 +0000)]
arm64: kvm: report original PAR_EL1 upon panic
If we call __kvm_hyp_panic while a guest context is active, we call
__restore_sysregs before acquiring the system register values for the
panic, in the process throwing away the PAR_EL1 value at the point of
the panic.
This patch modifies __kvm_hyp_panic to stash the PAR_EL1 value prior to
restoring host register values, enabling us to report the original
values at the point of the panic.
Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Mark Rutland [Mon, 16 Nov 2015 13:55:51 +0000 (13:55 +0000)]
arm64: kvm: avoid %p in __kvm_hyp_panic
Currently __kvm_hyp_panic uses %p for values which are not pointers,
such as the ESR value. This can confusingly lead to "(null)" being
printed for the value.
Use %x instead, and only use %p for host pointers.
Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Cc: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Christoffer Dall [Tue, 24 Nov 2015 15:34:31 +0000 (16:34 +0100)]
KVM: arm/arm64: vgic: Trust the LR state for HW IRQs
We were probing the physial distributor state for the active state of a
HW virtual IRQ, because we had seen evidence that the LR state was not
cleared when the guest deactivated a virtual interrupted.
However, this issue turned out to be a software bug in the GIC, which
was solved by: 84aab5e68c2a5e1e18d81ae8308c3ce25d501b29
(KVM: arm/arm64: arch_timer: Preserve physical dist. active
state on LR.active, 2015-11-24)
Therefore, get rid of the complexities and just look at the LR.
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Christoffer Dall [Tue, 24 Nov 2015 15:23:05 +0000 (16:23 +0100)]
KVM: arm/arm64: arch_timer: Preserve physical dist. active state on LR.active
We were incorrectly removing the active state from the physical
distributor on the timer interrupt when the timer output level was
deasserted. We shouldn't be doing this without considering the virtual
interrupt's active state, because the architecture requires that when an
LR has the HW bit set and the pending or active bits set, then the
physical interrupt must also have the corresponding bits set.
This addresses an issue where we have been observing an inconsistency
between the LR state and the physical distributor state where the LR
state was active and the physical distributor was not active, which
shouldn't happen.
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Christoffer Dall [Tue, 24 Nov 2015 09:31:07 +0000 (10:31 +0100)]
KVM: arm/arm64: Fix preemptible timer active state crazyness
We were setting the physical active state on the GIC distributor in a
preemptible section, which could cause us to set the active state on
different physical CPU from the one we were actually going to run on,
hacoc ensues.
Since we are no longer descheduling/scheduling soft timers in the
flush/sync timer functions, simply moving the timer flush into a
non-preemptible section.
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Marc Zyngier [Mon, 16 Nov 2015 10:28:18 +0000 (10:28 +0000)]
arm64: KVM: Add workaround for Cortex-A57 erratum 834220
Cortex-A57 parts up to r1p2 can misreport Stage 2 translation faults
when a Stage 1 permission fault or device alignment fault should
have been reported.
This patch implements the workaround (which is to validate that the
Stage-1 translation actually succeeds) by using code patching.
Cc: stable@vger.kernel.org Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Marc Zyngier [Mon, 16 Nov 2015 10:28:17 +0000 (10:28 +0000)]
arm64: KVM: Fix AArch32 to AArch64 register mapping
When running a 32bit guest under a 64bit hypervisor, the ARMv8
architecture defines a mapping of the 32bit registers in the 64bit
space. This includes banked registers that are being demultiplexed
over the 64bit ones.
On exceptions caused by an operation involving a 32bit register, the
HW exposes the register number in the ESR_EL2 register. It was so
far understood that SW had to distinguish between AArch32 and AArch64
accesses (based on the current AArch32 mode and register number).
It turns out that I misinterpreted the ARM ARM, and the clue is in
D1.20.1: "For some exceptions, the exception syndrome given in the
ESR_ELx identifies one or more register numbers from the issued
instruction that generated the exception. Where the exception is
taken from an Exception level using AArch32 these register numbers
give the AArch64 view of the register."
Which means that the HW is already giving us the translated version,
and that we shouldn't try to interpret it at all (for example, doing
an MMIO operation from the IRQ mode using the LR register leads to
very unexpected behaviours).
The fix is thus not to perform a call to vcpu_reg32() at all from
vcpu_reg(), and use whatever register number is supplied directly.
The only case we need to find out about the mapping is when we
actively generate a register access, which only occurs when injecting
a fault in a guest.
Cc: stable@vger.kernel.org Reviewed-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Ard Biesheuvel [Tue, 10 Nov 2015 14:11:20 +0000 (15:11 +0100)]
ARM/arm64: KVM: test properly for a PTE's uncachedness
The open coded tests for checking whether a PTE maps a page as
uncached use a flawed '(pte_val(xxx) & CONST) != CONST' pattern,
which is not guaranteed to work since the type of a mapping is
not a set of mutually exclusive bits
For HYP mappings, the type is an index into the MAIR table (i.e, the
index itself does not contain any information whatsoever about the
type of the mapping), and for stage-2 mappings it is a bit field where
normal memory and device types are defined as follows:
I.e., masking *and* comparing with the latter matches on the former,
and we have been getting lucky merely because the S2 device mappings
also have the PTE_UXN bit set, or we would misidentify memory mappings
as device mappings.
Since the unmap_range() code path (which contains one instance of the
flawed test) is used both for HYP mappings and stage-2 mappings, and
considering the difference between the two, it is non-trivial to fix
this by rewriting the tests in place, as it would involve passing
down the type of mapping through all the functions.
However, since HYP mappings and stage-2 mappings both deal with host
physical addresses, we can simply check whether the mapping is backed
by memory that is managed by the host kernel, and only perform the
D-cache maintenance if this is the case.
Cc: stable@vger.kernel.org Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Pavel Fedin <p.fedin@samsung.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Linus Torvalds [Sun, 22 Nov 2015 23:21:40 +0000 (15:21 -0800)]
Merge branch 'akpm' (patches from Andrew)
Merge slub bulk allocator updates from Andrew Morton:
"This missed the merge window because I was waiting for some repairs to
come in. Nothing actually uses the bulk allocator yet and the changes
to other code paths are pretty small. And the net guys are waiting
for this so they can start merging the client code"
More comments from Jesper Dangaard Brouer:
"The kmem_cache_alloc_bulk() call, in mm/slub.c, were included in
previous kernel. The present version contains a bug. Vladimir
Davydov noticed it contained a bug, when kernel is compiled with
CONFIG_MEMCG_KMEM (see commit 03ec0ed57ffc: "slub: fix kmem cgroup
bug in kmem_cache_alloc_bulk"). Plus the mem cgroup counterpart in
kmem_cache_free_bulk() were missing (see commit 033745189b1b "slub:
add missing kmem cgroup support to kmem_cache_free_bulk").
I don't consider the fix stable-material because there are no in-tree
users of the API.
But with known bugs (for memcg) I cannot start using the API in the
net-tree"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
slab/slub: adjust kmem_cache_alloc_bulk API
slub: add missing kmem cgroup support to kmem_cache_free_bulk
slub: fix kmem cgroup bug in kmem_cache_alloc_bulk
slub: optimize bulk slowpath free by detached freelist
slub: support for bulk free with SLUB freelists
Linus Torvalds [Sun, 22 Nov 2015 23:10:57 +0000 (15:10 -0800)]
Merge tag 'tty-4.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial fixes from Greg KH:
"Here are a few small tty/serial driver fixes for 4.4-rc2 that resolve
some reported problems.
All have been in linux-next, full details are in the shortlog below"
* tag 'tty-4.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
serial: export fsl8250_handle_irq
serial: 8250_mid: Add missing dependency
tty: audit: Fix audit source
serial: etraxfs-uart: Fix crash
serial: fsl_lpuart: Fix earlycon support
bcm63xx_uart: Use the device name when registering an interrupt
tty: Fix direct use of tty buffer work
tty: Fix tty_send_xchar() lock order inversion
Linus Torvalds [Sun, 22 Nov 2015 21:26:24 +0000 (13:26 -0800)]
Merge tag 'staging-4.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
Pull staging/IIO fixes from Greg KH:
"Here are some staging and iio driver fixes for 4.4-rc2. All of these
are in response to issues that have been reported and have been in
linux-next for a while"
* tag 'staging-4.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
Revert "Staging: wilc1000: coreconfigurator: Drop unneeded wrapper functions"
iio: adc: xilinx: Fix VREFN scale
iio: si7020: Swap data byte order
iio: adc: vf610_adc: Fix division by zero error
iio:ad7793: Fix ad7785 product ID
iio: ad5064: Fix ad5629/ad5669 shift
iio:ad5064: Make sure ad5064_i2c_write() returns 0 on success
iio: lpc32xx_adc: fix warnings caused by enabling unprepared clock
staging: iio: select IRQ_WORK for IIO_DUMMY_EVGEN
vf610_adc: Fix internal temperature calculation
Linus Torvalds [Sun, 22 Nov 2015 21:15:05 +0000 (13:15 -0800)]
Merge tag 'usb-4.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
Pull USB fixes from Greg KH:
"Here are a number of USB fixes and new device ids for 4.4-rc2. All
have been in linux-next and the details are in the shortlog"
* tag 'usb-4.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (28 commits)
usblp: do not set TASK_INTERRUPTIBLE before lock
USB: MAINTAINERS: cxacru
usb: kconfig: fix warning of select USB_OTG
USB: option: add XS Stick W100-2 from 4G Systems
xhci: Fix a race in usb2 LPM resume, blocking U3 for usb2 devices
usb: xhci: fix checking ep busy for CFC
xhci: Workaround to get Intel xHCI reset working more reliably
usb: chipidea: imx: fix a possible NULL dereference
usb: chipidea: usbmisc_imx: fix a possible NULL dereference
usb: chipidea: otg: gadget module load and unload support
usb: chipidea: debug: disable usb irq while role switch
ARM: dts: imx27.dtsi: change the clock information for usb
usb: chipidea: imx: refine clock operations to adapt for all platforms
usb: gadget: atmel_usba_udc: Expose correct device speed
usb: musb: enable usb_dma parameter
usb: phy: phy-mxs-usb: fix a possible NULL dereference
usb: dwc3: gadget: let us set lower max_speed
usb: musb: fix tx fifo flush handling
usb: gadget: f_loopback: fix the warning during the enumeration
usb: dwc2: host: Fix remote wakeup when not in DWC2_L2
...
Linus Torvalds [Sun, 22 Nov 2015 20:59:46 +0000 (12:59 -0800)]
Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
Pull MIPS fixes from Ralf Baechle:
- Fix a flood of annoying build warnings
- A number of fixes for Atheros 79xx platforms
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
MIPS: ath79: Add a machine entry for booting OF machines
MIPS: ath79: Fix the size of the MISC INTC registers in ar9132.dtsi
MIPS: ath79: Fix the DDR control initialization on ar71xx and ar934x
MIPS: Fix flood of warnings about comparsion being always true.
Linus Torvalds [Sun, 22 Nov 2015 20:50:58 +0000 (12:50 -0800)]
Merge branch 'parisc-4.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux
Pull parisc update from Helge Deller:
"This patchset adds Huge Page and HUGETLBFS support for parisc"
Honestly, the hugepage support should have gone through in the merge
window, and is not really an rc-time fix. But it only touches
arch/parisc, and I cannot find it in myself to care. If one of the
three parisc users notices a breakage, I will point at Helge and make
rude farting noises.
* 'parisc-4.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
parisc: Map kernel text and data on huge pages
parisc: Add Huge Page and HUGETLBFS support
parisc: Use long branch to do_syscall_trace_exit
parisc: Increase initial kernel mapping to 32MB on 64bit kernel
parisc: Initialize the fault vector earlier in the boot process.
parisc: Add defines for Huge page support
parisc: Drop unused MADV_xxxK_PAGES flags from asm/mman.h
parisc: Drop definition of start_thread_som for HP-UX SOM binaries
parisc: Fix wrong comment regarding first pmd entry flags
Linus Torvalds [Sun, 22 Nov 2015 20:37:20 +0000 (12:37 -0800)]
Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf tool fixes from Thomas Gleixner:
"A couple of fixes for perf tools:
- Build system updates
- Plug a memory leak in an error path of perf probe
- Tear down probes correctly when adding fails
- Fixes to the perf symbol handling
- Fix ordering of event processing in buildid-list
- Fix per DSO filtering in the histogram browser"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf probe: Clear probe_trace_event when add_probe_trace_event() fails
perf probe: Fix memory leaking on failure by clearing all probe_trace_events
perf inject: Also re-pipe lost_samples event
perf buildid-list: Requires ordered events
perf symbols: Fix dso lookup by long name and missing buildids
perf symbols: Allow forcing reading of non-root owned files by root
perf hists browser: The dso can be obtained from popup_action->ms.map->dso
perf hists browser: Fix 'd' hotkey action to filter by DSO
perf symbols: Rebuild rbtree when adjusting symbols for kcore
tools: Add a "make all" rule
tools: Actually install tmon in the install rule
Linus Torvalds [Sun, 22 Nov 2015 20:00:12 +0000 (12:00 -0800)]
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
"This update contains:
- MPX updates for handling 32bit processes
- A fix for a long standing bug in 32bit signal frame handling
related to FPU/XSAVE state
- Handle get_xsave_addr() correctly in KVM
- Fix SMAP check under paravirtualization
- Add a comment to the static function trace entry to avoid further
confusion about the difference to dynamic tracing"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/cpu: Fix SMAP check in PVOPS environments
x86/ftrace: Add comment on static function tracing
x86/fpu: Fix get_xsave_addr() behavior under virtualization
x86/fpu: Fix 32-bit signal frame handling
x86/mpx: Fix 32-bit address space calculation
x86/mpx: Do proper get_user() when running 32-bit binaries on 64-bit kernels
Adjust kmem_cache_alloc_bulk API before we have any real users.
Adjust API to return type 'int' instead of previously type 'bool'. This
is done to allow future extension of the bulk alloc API.
A future extension could be to allow SLUB to stop at a page boundary, when
specified by a flag, and then return the number of objects.
The advantage of this approach, would make it easier to make bulk alloc
run without local IRQs disabled. With an approach of cmpxchg "stealing"
the entire c->freelist or page->freelist. To avoid overshooting we would
stop processing at a slab-page boundary. Else we always end up returning
some objects at the cost of another cmpxchg.
To keep compatible with future users of this API linking against an older
kernel when using the new flag, we need to return the number of allocated
objects with this API change.
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
slub: add missing kmem cgroup support to kmem_cache_free_bulk
Initial implementation missed support for kmem cgroup support in
kmem_cache_free_bulk() call, add this.
If CONFIG_MEMCG_KMEM is not enabled, the compiler should be smart enough
to not add any asm code.
Incoming bulk free objects can belong to different kmem cgroups, and
object free call can happen at a later point outside memcg context. Thus,
we need to keep the orig kmem_cache, to correctly verify if a memcg object
match against its "root_cache" (s->memcg_params.root_cache).
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
slub: fix kmem cgroup bug in kmem_cache_alloc_bulk
The call slab_pre_alloc_hook() interacts with kmemgc and is not allowed to
be called several times inside the bulk alloc for loop, due to the call to
memcg_kmem_get_cache().
This would result in hitting the VM_BUG_ON in __memcg_kmem_get_cache.
As suggested by Vladimir Davydov, change slab_post_alloc_hook() to be able
to handle an array of objects.
A subtle detail is, loop iterator "i" in slab_post_alloc_hook() must have
same type (size_t) as size argument. This helps the compiler to easier
realize that it can remove the loop, when all debug statements inside loop
evaluates to nothing. Note, this is only an issue because the kernel is
compiled with GCC option: -fno-strict-overflow
In slab_alloc_node() the compiler inlines and optimizes the invocation of
slab_post_alloc_hook(s, flags, 1, &object) by removing the loop and access
object directly.
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Reported-by: Vladimir Davydov <vdavydov@virtuozzo.com> Suggested-by: Vladimir Davydov <vdavydov@virtuozzo.com> Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
slub: optimize bulk slowpath free by detached freelist
This change focus on improving the speed of object freeing in the
"slowpath" of kmem_cache_free_bulk.
The calls slab_free (fastpath) and __slab_free (slowpath) have been
extended with support for bulk free, which amortize the overhead of
the (locked) cmpxchg_double.
To use the new bulking feature, we build what I call a detached
freelist. The detached freelist takes advantage of three properties:
1) the free function call owns the object that is about to be freed,
thus writing into this memory is synchronization-free.
2) many freelist's can co-exist side-by-side in the same slab-page
each with a separate head pointer.
3) it is the visibility of the head pointer that needs synchronization.
Given these properties, the brilliant part is that the detached
freelist can be constructed without any need for synchronization. The
freelist is constructed directly in the page objects, without any
synchronization needed. The detached freelist is allocated on the
stack of the function call kmem_cache_free_bulk. Thus, the freelist
head pointer is not visible to other CPUs.
All objects in a SLUB freelist must belong to the same slab-page.
Thus, constructing the detached freelist is about matching objects
that belong to the same slab-page. The bulk free array is scanned is
a progressive manor with a limited look-ahead facility.
Kmem debug support is handled in call of slab_free().
Notice kmem_cache_free_bulk no longer need to disable IRQs. This
only slowed down single free bulk with approx 3 cycles.
Performance data:
Benchmarked[1] obj size 256 bytes on CPU i7-4790K @ 4.00GHz
SLUB fastpath single object quick reuse: 47 cycles(tsc) 11.931 ns
To get stable and comparable numbers, the kernel have been booted with
"slab_merge" (this also improve performance for larger bulk sizes).
Performance data, compared against fallback bulking:
Performance with normal SLUB merging is significantly slower for
larger bulking. This is believed to (primarily) be an effect of not
having to share the per-CPU data-structures, as tuning per-CPU size
can achieve similar performance.
Make it possible to free a freelist with several objects by adjusting API
of slab_free() and __slab_free() to have head, tail and an objects counter
(cnt).
Tail being NULL indicate single object free of head object. This allow
compiler inline constant propagation in slab_free() and
slab_free_freelist_hook() to avoid adding any overhead in case of single
object free.
This allows a freelist with several objects (all within the same
slab-page) to be free'ed using a single locked cmpxchg_double in
__slab_free() and with an unlocked cmpxchg_double in slab_free().
Object debugging on the free path is also extended to handle these
freelists. When CONFIG_SLUB_DEBUG is enabled it will also detect if
objects don't belong to the same slab-page.
These changes are needed for the next patch to bulk free the detached
freelists it introduces and constructs.
Micro benchmarking showed no performance reduction due to this change,
when debugging is turned off (compiled with CONFIG_SLUB_DEBUG).
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com> Acked-by: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Helge Deller [Sat, 21 Nov 2015 23:07:06 +0000 (00:07 +0100)]
parisc: Add Huge Page and HUGETLBFS support
This patch adds huge page support to allow userspace to allocate huge
pages and to use hugetlbfs filesystem on 32- and 64-bit Linux kernels.
A later patch will add kernel support to map kernel text and data on
huge pages.
The only requirement is, that the kernel needs to be compiled for a
PA8X00 CPU (PA2.0 architecture). Older PA1.X CPUs do not support
variable page sizes. 64bit Kernels are compiled for PA2.0 by default.
Technically on parisc multiple physical huge pages may be needed to
emulate standard 2MB huge pages.
Helge Deller [Fri, 20 Nov 2015 10:22:32 +0000 (11:22 +0100)]
parisc: Use long branch to do_syscall_trace_exit
Use the 22bit instead of the 17bit branch instruction on a 64bit kernel
to reach the do_syscall_trace_exit function from the gateway page.
A huge page enabled kernel may need the additional branch distance bits.
Helge Deller [Fri, 20 Nov 2015 10:17:27 +0000 (11:17 +0100)]
parisc: Increase initial kernel mapping to 32MB on 64bit kernel
For the 64bit kernel the initially 16 MB kernel memory might become too
small if you build a kernel with many modules built-in and with kernel
text and data areas mapped on huge pages.
This patch increases the initial mapping to 32MB for 64bit kernels and
keeps 16MB for 32bit kernels.
Helge Deller [Fri, 20 Nov 2015 09:50:01 +0000 (10:50 +0100)]
parisc: Initialize the fault vector earlier in the boot process.
A fault vector on parisc needs to be 2K aligned. Furthermore the
checksum of the fault vector needs to sum up to 0 which is being
calculated and written at runtime.
Up to now we aligned both PA20 and PA11 fault vectors on the same 4K
page in order to easily write the checksum after having mapped the
kernel read-only (by mapping this page only as read-write).
But when we want to map the kernel text and data on huge pages this
makes things harder.
So, simplify it by aligning both fault vectors on 2K boundries and write
the checksum before we map the page read-only.
Helge Deller [Fri, 20 Nov 2015 14:46:52 +0000 (15:46 +0100)]
parisc: Add defines for Huge page support
Huge pages on parisc will have the same size as one pmd table, which
is on a 64bit kernel 2MB on a kernel with 4K kernel page sizes, and
on a 32bit kernel 4MB when used with 4K kernel pages.
Since parisc does not physically supports 2MB huge page sizes, emulate
it with two consecutive 1MB page sizes instead. Keeping the same huge
page size as one pmd will allow us to add transparent huge page support
later on.
Bit 21 in the pte flags was unused and will now be used to mark a page
as huge page (_PAGE_HPAGE_BIT).
Linus Torvalds [Sat, 21 Nov 2015 18:49:13 +0000 (10:49 -0800)]
Merge branch 'akpm' (patches from Andrew)
Merge misc fixes from Andrew Morton:
"A bunch of fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
slub: mark the dangling ifdef #else of CONFIG_SLUB_DEBUG
slub: avoid irqoff/on in bulk allocation
slub: create new ___slab_alloc function that can be called with irqs disabled
mm: fix up sparse warning in gfpflags_allow_blocking
ocfs2: fix umask ignored issue
PM/OPP: add entry in MAINTAINERS
kernel/panic.c: turn off locks debug before releasing console lock
kernel/signal.c: unexport sigsuspend()
kasan: fix kmemleak false-positive in kasan_module_alloc()
fat: fix fake_offset handling on error path
mm/hugetlbfs: fix bugs in fallocate hole punch of areas with holes
mm/page-writeback.c: initialize m_dirty to avoid compile warning
various: fix pci_set_dma_mask return value checking
mm: loosen MADV_NOHUGEPAGE to enable Qemu postcopy on s390
mm: vmalloc: don't remove inexistent guard hole in remove_vm_area()
tools/vm/page-types.c: support KPF_IDLE
ncpfs: don't allow negative timeouts
configfs: allow dynamic group creation
MAINTAINERS: add Moritz as reviewer for FPGA Manager Framework
slab.h: sprinkle __assume_aligned attributes
Linus Torvalds [Sat, 21 Nov 2015 18:19:15 +0000 (10:19 -0800)]
Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fixes from Thomas Gleixner:
"Three fixes for the ARM GIC interrupt controller from Marc addressing
various shortcomings versus boot initialization and suspend/resume"
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/gic: Add save/restore of the active state
irqchip/gic: Clear enable bits before restoring them
irqchip/gic: Make sure all interrupts are deactivated at boot
Linus Torvalds [Sat, 21 Nov 2015 17:52:07 +0000 (09:52 -0800)]
Merge tag 'for-linus-20151120' of git://git.infradead.org/linux-mtd
Pull MTD fixes from Brian Norris:
- MAINTAINERS updates for brcmnand driver
- Fix reboot hangs seen when multiple NAND flash chips are registered
with the same controller
- Fix build issues on jz4740 NAND driver; the error was introduced in
4.3, so I guess nobody really cared, but we might as well fix it
* tag 'for-linus-20151120' of git://git.infradead.org/linux-mtd:
MAINTAINERS: brcmnand: Add co-maintainer for Broadcom SoCs
MAINTAINERS: brcmnand: Add Broadcom internal mailing-list
mtd: nand: fix shutdown/reboot for multi-chip systems
mtd: jz4740_nand: fix build on jz4740 after removing gpio.h
projects / karo-tx-linux.git / log