Commit Graph

205 Commits

Author SHA1 Message Date
Thomas Gleixner
caab277b1d treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation this program is
  distributed in the hope that it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details you should have received a copy of the gnu general
  public license along with this program if not see http www gnu org
  licenses

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 503 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Enrico Weigelt <info@metux.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:07 +02:00
Thomas Gleixner
5dfa3c2f10 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 342
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license this
  program is distributed in the hope that it will be useful but
  without any warranty without even the implied warranty of
  merchantability or fitness for a particular purpose see the gnu
  general public license for more details you should have received a
  copy of the gnu general public license along with this program if
  not see http www gnu org licenses

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 15 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190530000437.237481593@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05 17:37:07 +02:00
Thomas Gleixner
4505153954 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation this program is
  distributed in the hope that it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details you should have received a copy of the gnu general
  public license along with this program if not write to the free
  software foundation inc 59 temple place suite 330 boston ma 02111
  1307 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 136 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190530000436.384967451@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05 17:37:06 +02:00
Linus Torvalds
636deed6c0 ARM: some cleanups, direct physical timer assignment, cache sanitization
for 32-bit guests
 
 s390: interrupt cleanup, introduction of the Guest Information Block,
 preparation for processor subfunctions in cpu models
 
 PPC: bug fixes and improvements, especially related to machine checks
 and protection keys
 
 x86: many, many cleanups, including removing a bunch of MMU code for
 unnecessary optimizations; plus AVIC fixes.
 
 Generic: memcg accounting
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.22 (GNU/Linux)
 
 iQEcBAABAgAGBQJci+7XAAoJEL/70l94x66DUMkIAKvEefhceySHYiTpfefjLjIC
 16RewgHa+9CO4Oo5iXiWd90fKxtXLXmxDQOS4VGzN0rxvLGRw/fyXIxL1MDOkaAO
 l8SLSNuewY4XBUgISL3PMz123r18DAGOuy9mEcYU/IMesYD2F+wy5lJ17HIGq6X2
 RpoF1p3qO1jfkPTKOob6Ixd4H5beJNPKpdth7LY3PJaVhDxgouj32fxnLnATVSnN
 gENQ10fnt8BCjshRYW6Z2/9bF15JCkUFR1xdBW2/xh1oj+kvPqqqk2bEN1eVQzUy
 2hT/XkwtpthqjSbX8NNavWRSFnOnbMLTRKQyIXmFVsM5VoSrwtiGsCFzBgcT++I=
 =XIzU
 -----END PGP SIGNATURE-----

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Paolo Bonzini:
 "ARM:
   - some cleanups
   - direct physical timer assignment
   - cache sanitization for 32-bit guests

  s390:
   - interrupt cleanup
   - introduction of the Guest Information Block
   - preparation for processor subfunctions in cpu models

  PPC:
   - bug fixes and improvements, especially related to machine checks
     and protection keys

  x86:
   - many, many cleanups, including removing a bunch of MMU code for
     unnecessary optimizations
   - AVIC fixes

  Generic:
   - memcg accounting"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (147 commits)
  kvm: vmx: fix formatting of a comment
  KVM: doc: Document the life cycle of a VM and its resources
  MAINTAINERS: Add KVM selftests to existing KVM entry
  Revert "KVM/MMU: Flush tlb directly in the kvm_zap_gfn_range()"
  KVM: PPC: Book3S: Add count cache flush parameters to kvmppc_get_cpu_char()
  KVM: PPC: Fix compilation when KVM is not enabled
  KVM: Minor cleanups for kvm_main.c
  KVM: s390: add debug logging for cpu model subfunctions
  KVM: s390: implement subfunction processor calls
  arm64: KVM: Fix architecturally invalid reset value for FPEXC32_EL2
  KVM: arm/arm64: Remove unused timer variable
  KVM: PPC: Book3S: Improve KVM reference counting
  KVM: PPC: Book3S HV: Fix build failure without IOMMU support
  Revert "KVM: Eliminate extra function calls in kvm_get_dirty_log_protect()"
  x86: kvmguest: use TSC clocksource if invariant TSC is exposed
  KVM: Never start grow vCPU halt_poll_ns from value below halt_poll_ns_grow_start
  KVM: Expose the initial start value in grow_halt_poll_ns() as a module parameter
  KVM: grow_halt_poll_ns() should never shrink vCPU halt_poll_ns
  KVM: x86/mmu: Consolidate kvm_mmu_zap_all() and kvm_mmu_zap_mmio_sptes()
  KVM: x86/mmu: WARN if zapping a MMIO spte results in zapping children
  ...
2019-03-15 15:00:28 -07:00
Christoffer Dall
bee038a674 KVM: arm/arm64: Rework the timer code to use a timer_map
We are currently emulating two timers in two different ways.  When we
add support for nested virtualization in the future, we are going to be
emulating either two timers in two diffferent ways, or four timers in a
single way.

We need a unified data structure to keep track of how we map virtual
state to physical state and we need to cleanup some of the timer code to
operate more independently on a struct arch_timer_context instead of
trying to consider the global state of the VCPU and recomputing all
state.

Co-written with Marc Zyngier <marc.zyngier@arm.com>

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
2019-02-19 21:05:43 +00:00
Christoffer Dall
9e01dc76be KVM: arm/arm64: arch_timer: Assign the phys timer on VHE systems
VHE systems don't have to emulate the physical timer, we can simply
assign the EL1 physical timer directly to the VM as the host always
uses the EL2 timers.

In order to minimize the amount of cruft, AArch32 gets definitions for
the physical timer too, but is should be generally unused on this
architecture.

Co-written with Marc Zyngier <marc.zyngier@arm.com>

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
2019-02-19 21:05:42 +00:00
Christoffer Dall
e604dd5d45 KVM: arm/arm64: timer: Rework data structures for multiple timers
Prepare for having 4 timer data structures (2 for now).

Move loaded to the cpu data structure and not the individual timer
structure, in preparation for assigning the EL1 phys timer as well.

Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-02-19 21:05:41 +00:00
Andre Przywara
84135d3d18 KVM: arm/arm64: consolidate arch timer trap handlers
At the moment we have separate system register emulation handlers for
each timer register. Actually they are quite similar, and we rely on
kvm_arm_timer_[gs]et_reg() for the actual emulation anyways, so let's
just merge all of those handlers into one function, which just marshalls
the arguments and then hands off to a set of common accessors.
This makes extending the emulation to include EL2 timers much easier.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
[Fixed 32-bit VM breakage and reduced to reworking existing code]
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
[Fixed 32bit host, general cleanup]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-02-19 21:05:40 +00:00
Christoffer Dall
accb99bcd0 KVM: arm/arm64: Simplify bg_timer programming
Instead of calling into kvm_timer_[un]schedule from the main kvm
blocking path, test if the VCPU is on the wait queue from the load/put
path and perform the background timer setup/cancel in this path.

This has the distinct advantage that we no longer race between load/put
and schedule/unschedule and programming and canceling of the bg_timer
always happens when the timer state is not loaded.

Note that we must now remove the checks in kvm_timer_blocking that do
not schedule a background timer if one of the timers can fire, because
we no longer have a guarantee that kvm_vcpu_check_block() will be called
before kvm_timer_blocking.

Reported-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-02-19 21:05:36 +00:00
Julien Thierry
e08d8d2960 KVM: arm/arm64: vgic: Make vgic_cpu->ap_list_lock a raw_spinlock
vgic_cpu->ap_list_lock must always be taken with interrupts disabled as
it is used in interrupt context.

For configurations such as PREEMPT_RT_FULL, this means that it should
be a raw_spinlock since RT spinlocks are interruptible.

Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
2019-01-24 15:09:09 +01:00
Julien Thierry
fc3bc47523 KVM: arm/arm64: vgic: Make vgic_dist->lpi_list_lock a raw_spinlock
vgic_dist->lpi_list_lock must always be taken with interrupts disabled as
it is used in interrupt context.

For configurations such as PREEMPT_RT_FULL, this means that it should
be a raw_spinlock since RT spinlocks are interruptible.

Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
2019-01-24 15:09:01 +01:00
Julien Thierry
8fa3adb8c6 KVM: arm/arm64: vgic: Make vgic_irq->irq_lock a raw_spinlock
vgic_irq->irq_lock must always be taken with interrupts disabled as
it is used in interrupt context.

For configurations such as PREEMPT_RT_FULL, this means that it should
be a raw_spinlock since RT spinlocks are interruptible.

Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
2019-01-24 15:08:50 +01:00
Christoffer Dall
8a411b060f KVM: arm/arm64: Remove arch timer workqueue
The use of a work queue in the hrtimer expire function for the bg_timer
is a leftover from the time when we would inject interrupts when the
bg_timer expired.

Since we are no longer doing that, we can instead call
kvm_vcpu_wake_up() directly from the hrtimer function and remove all
workqueue functionality from the arch timer code.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-19 17:47:07 +00:00
Marc Zyngier
6249f2a479 KVM: arm/arm64: vgic-v3: Add core support for Group0 SGIs
Although vgic-v3 now supports Group0 interrupts, it still doesn't
deal with Group0 SGIs. As usually with the GIC, nothing is simple:

- ICC_SGI1R can signal SGIs of both groups, since GICD_CTLR.DS==1
  with KVM (as per 8.1.10, Non-secure EL1 access)

- ICC_SGI0R can only generate Group0 SGIs

- ICC_ASGI1R sees its scope refocussed to generate only Group0
  SGIs (as per the note at the bottom of Table 8-14)

We only support Group1 SGIs so far, so no material change.

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-08-12 12:06:34 +01:00
Christoffer Dall
32f8777ed9 KVM: arm/arm64: vgic: Let userspace opt-in to writable v2 IGROUPR
Simply letting IGROUPR be writable from userspace would break
migration from old kernels to newer kernels, because old kernels
incorrectly report interrupt groups as group 1.  This would not be a big
problem if userspace wrote GICD_IIDR as read from the kernel, because we
could detect the incompatibility and return an error to userspace.
Unfortunately, this is not the case with current userspace
implementations and simply letting IGROUPR be writable from userspace for
an emulated GICv2 silently breaks migration and causes the destination
VM to no longer run after migration.

We now encourage userspace to write the read and expected value of
GICD_IIDR as the first part of a GIC register restore, and if we observe
a write to GICD_IIDR we know that userspace has been updated and has had
a chance to cope with older kernels (VGICv2 IIDR.Revision == 0)
incorrectly reporting interrupts as group 1, and therefore we now allow
groups to be user writable.

Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-07-21 16:02:29 +01:00
Christoffer Dall
8df3c8f33f KVM: arm/arm64: vgic: Add group field to struct irq
In preparation for proper group 0 and group 1 support in the vgic, we
add a field in the struct irq to store the group of all interrupts.

We initialize the group to group 0 when emulating GICv2 and to group 1
when emulating GICv3, just like we treat them today.  LPIs are always
group 1.  We also continue to ignore writes from the guest, preserving
existing functionality, for now.

Finally, we also add this field to the vgic debug logic to show the
group for all interrupts.

Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-07-21 16:02:24 +01:00
Christoffer Dall
aa075b0f30 KVM: arm/arm64: vgic: Keep track of implementation revision
As we are about to tweak implementation aspects of the VGIC emulation,
while still preserving some level of backwards compatibility support,
add a field to keep track of the implementation revision field which is
reported to the VM and to userspace.

Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-07-21 16:02:21 +01:00
Eric Auger
e25028c8de KVM: arm/arm64: Bump VGIC_V3_MAX_CPUS to 512
Let's raise the number of supported vcpus along with
vgic v3 now that HW is looming with more physical CPUs.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-05-25 12:29:27 +01:00
Eric Auger
5ec17fbac6 KVM: arm/arm64: Remove kvm_vgic_vcpu_early_init
kvm_vgic_vcpu_early_init gets called after kvm_vgic_cpu_init which
is confusing. The call path is as follows:
kvm_vm_ioctl_create_vcpu
|_ kvm_arch_cpu_create
   |_ kvm_vcpu_init
      |_ kvm_arch_vcpu_init
         |_ kvm_vgic_vcpu_init
|_ kvm_arch_vcpu_postcreate
   |_ kvm_vgic_vcpu_early_init

Static initialization currently done in kvm_vgic_vcpu_early_init()
can be moved to kvm_vgic_vcpu_init(). So let's move the code and
remove kvm_vgic_vcpu_early_init(). kvm_arch_vcpu_postcreate() does
nothing.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-05-25 12:29:27 +01:00
Eric Auger
dbd9733ab6 KVM: arm/arm64: Replace the single rdist region by a list
At the moment KVM supports a single rdist region. We want to
support several separate rdist regions so let's introduce a list
of them. This patch currently only cares about a single
entry in this list as the functionality to register several redist
regions is not yet there. So this only translates the existing code
into something functionally similar using that new data struct.

The redistributor region handle is stored in the vgic_cpu structure
to allow later computation of the TYPER last bit.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-05-25 12:29:26 +01:00
Marc Zyngier
53692908b0 KVM: arm/arm64: vgic: Fix source vcpu issues for GICv2 SGI
Now that we make sure we don't inject multiple instances of the
same GICv2 SGI at the same time, we've made another bug more
obvious:

If we exit with an active SGI, we completely lose track of which
vcpu it came from. On the next entry, we restore it with 0 as a
source, and if that wasn't the right one, too bad. While this
doesn't seem to trouble GIC-400, the architectural model gets
offended and doesn't deactivate the interrupt on EOI.

Another connected issue is that we will happilly make pending
an interrupt from another vcpu, overriding the above zero with
something that is just as inconsistent. Don't do that.

The final issue is that we signal a maintenance interrupt when
no pending interrupts are present in the LR. Assuming we've fixed
the two issues above, we end-up in a situation where we keep
exiting as soon as we've reached the active state, and not be
able to inject the following pending.

The fix comes in 3 parts:
- GICv2 SGIs have their source vcpu saved if they are active on
  exit, and restored on entry
- Multi-SGIs cannot go via the Pending+Active state, as this would
  corrupt the source field
- Multi-SGIs are converted to using MI on EOI instead of NPIE

Fixes: 16ca6a607d ("KVM: arm/arm64: vgic: Don't populate multiple LRs with the same vintid")
Reported-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-04-27 12:39:09 +01:00
Marc Zyngier
85bd0ba1ff arm/arm64: KVM: Add PSCI version selection API
Although we've implemented PSCI 0.1, 0.2 and 1.0, we expose either 0.1
or 1.0 to a guest, defaulting to the latest version of the PSCI
implementation that is compatible with the requested version. This is
no different from doing a firmware upgrade on KVM.

But in order to give a chance to hypothetical badly implemented guests
that would have a fit by discovering something other than PSCI 0.2,
let's provide a new API that allows userspace to pick one particular
version of the API.

This is implemented as a new class of "firmware" registers, where
we expose the PSCI version. This allows the PSCI version to be
save/restored as part of a guest migration, and also set to
any supported version if the guest requires it.

Cc: stable@vger.kernel.org #4.16
Reviewed-by: Christoffer Dall <cdall@kernel.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-04-20 16:32:23 +01:00
Marc Zyngier
5fbb0df6f6 kvm/arm fixes for 4.16, take 2
- Peace of mind locking fix in vgic_mmio_read_pending
 - Allow hw-mapped interrupts to be reset when the VM resets
 - Fix GICv2 multi-source SGI injection
 - Fix MMIO synchronization for GICv2 on v3 emulation
 - Remove excess verbosity on the console
 -----BEGIN PGP SIGNATURE-----
 
 iQJJBAABCAAzFiEEn9UcU+C1Yxj9lZw9I9DQutE9ekMFAlqqp/cVHG1hcmMuenlu
 Z2llckBhcm0uY29tAAoJECPQ0LrRPXpDAGkP/2LMhFN561PKlqgu5V4hFvowJiXb
 Gbb/qi095vtDGccbKmJKAZp3jyOM2oJEMUkx5RBYglWjW0mxb3zPAAxhldXiqv/2
 CrOGGlS/FwfyIjCt7870pltDOIgRmk8Fv/MyQjjGKF6VAghd6yVHIZiOUjiriUyz
 6hNyc2znLm0tBqm4j3HTXKHpD23YseW387pQoeQ03/WiXiZ60O3e3k0yppXO81qE
 b7TGT4Bz04mxlAISZVZeTmG7P7P4ej6+NhOH+1kxacseLzHdECPBA0JRcwRpfLkP
 5JFodUOX7/KHpvpMLUxRNRnLBei9WUL4o2LAEV0qDaj7nlAud0kKUm22RLaVKDm+
 8FSUQ12XKqnZsRrl6IizU1oAb1I1iV3j9HF5iNf3mk9AO27REGk0b8fDyRzDj300
 xpySgvIgA+f+EyY+3ve0AmEUa5QKz/WLuik2ZCqpVOuufrO8XpS+zjn1L1tzTlkR
 95EahDA7enutw47G0uWtxoPMeU4HTZS/CAiFwUbq8BEK7T3Rct7UySPLwgeYBoji
 MUlCRhPyAANCJmtO6rpOS3htkQ3XkkO1DVIGLuWC5Zl00W1T5I5+VRrVL1YI4v3O
 d2ui9r5X5Vmg4OUdhr2D9fXgPWWKEbqD90jv40rGLsMl0g/IwrC+o2VxgYxSeu5x
 CLUYILwEA5NDZSof
 =iyYE
 -----END PGP SIGNATURE-----

Merge tag 'kvm-arm-fixes-for-v4.16-2' into HEAD

Resolve conflicts with current mainline
2018-03-19 17:43:01 +00:00
Marc Zyngier
1bb32a44ae KVM: arm/arm64: Keep GICv2 HYP VAs in kvm_vgic_global_state
As we're about to change the way we map devices at HYP, we need
to move away from kern_hyp_va on an IO address.

One way of achieving this is to store the VAs in kvm_vgic_global_state,
and use that directly from the HYP code. This requires a small change
to create_hyp_io_mappings so that it can also return a HYP VA.

We take this opportunity to nuke the vctrl_base field in the emulated
distributor, as it is not used anymore.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 13:04:06 +00:00
Christoffer Dall
bb5ed70359 KVM: arm/arm64: Get rid of vgic_elrsr
There is really no need to store the vgic_elrsr on the VGIC data
structures as the only need we have for the elrsr is to figure out if an
LR is inactive when we save the VGIC state upon returning from the
guest.  We can might as well store this in a temporary local variable.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 10:53:20 +00:00
Christoffer Dall
413aa807ae KVM: arm/arm64: Reset mapped IRQs on VM reset
We currently don't allow resetting mapped IRQs from userspace, because
their state is controlled by the hardware.  But we do need to reset the
state when the VM is reset, so we provide a function for the 'owner' of
the mapped interrupt to reset the interrupt state.

Currently only the timer uses mapped interrupts, so we call this
function from the timer reset logic.

Cc: stable@vger.kernel.org
Fixes: 4c60e360d6 ("KVM: arm/arm64: Provide a get_input_level for the arch timer")
Signed-off-by: Christoffer Dall <cdall@kernel.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-14 18:29:14 +00:00
Linus Torvalds
15303ba5d1 KVM changes for 4.16
ARM:
 - Include icache invalidation optimizations, improving VM startup time
 
 - Support for forwarded level-triggered interrupts, improving
   performance for timers and passthrough platform devices
 
 - A small fix for power-management notifiers, and some cosmetic changes
 
 PPC:
 - Add MMIO emulation for vector loads and stores
 
 - Allow HPT guests to run on a radix host on POWER9 v2.2 CPUs without
   requiring the complex thread synchronization of older CPU versions
 
 - Improve the handling of escalation interrupts with the XIVE interrupt
   controller
 
 - Support decrement register migration
 
 - Various cleanups and bugfixes.
 
 s390:
 - Cornelia Huck passed maintainership to Janosch Frank
 
 - Exitless interrupts for emulated devices
 
 - Cleanup of cpuflag handling
 
 - kvm_stat counter improvements
 
 - VSIE improvements
 
 - mm cleanup
 
 x86:
 - Hypervisor part of SEV
 
 - UMIP, RDPID, and MSR_SMI_COUNT emulation
 
 - Paravirtualized TLB shootdown using the new KVM_VCPU_PREEMPTED bit
 
 - Allow guests to see TOPOEXT, GFNI, VAES, VPCLMULQDQ, and more AVX512
   features
 
 - Show vcpu id in its anonymous inode name
 
 - Many fixes and cleanups
 
 - Per-VCPU MSR bitmaps (already merged through x86/pti branch)
 
 - Stable KVM clock when nesting on Hyper-V (merged through x86/hyperv)
 -----BEGIN PGP SIGNATURE-----
 
 iQEcBAABCAAGBQJafvMtAAoJEED/6hsPKofo6YcH/Rzf2RmshrWaC3q82yfIV0Qz
 Z8N8yJHSaSdc3Jo6cmiVj0zelwAxdQcyjwlT7vxt5SL2yML+/Q0st9Hc3EgGGXPm
 Il99eJEl+2MYpZgYZqV8ff3mHS5s5Jms+7BITAeh6Rgt+DyNbykEAvzt+MCHK9cP
 xtsIZQlvRF7HIrpOlaRzOPp3sK2/MDZJ1RBE7wYItK3CUAmsHim/LVYKzZkRTij3
 /9b4LP1yMMbziG+Yxt1o682EwJB5YIat6fmDG9uFeEVI5rWWN7WFubqs8gCjYy/p
 FX+BjpOdgTRnX+1m9GIj0Jlc/HKMXryDfSZS07Zy4FbGEwSiI5SfKECub4mDhuE=
 =C/uD
 -----END PGP SIGNATURE-----

Merge tag 'kvm-4.16-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Radim Krčmář:
 "ARM:

   - icache invalidation optimizations, improving VM startup time

   - support for forwarded level-triggered interrupts, improving
     performance for timers and passthrough platform devices

   - a small fix for power-management notifiers, and some cosmetic
     changes

  PPC:

   - add MMIO emulation for vector loads and stores

   - allow HPT guests to run on a radix host on POWER9 v2.2 CPUs without
     requiring the complex thread synchronization of older CPU versions

   - improve the handling of escalation interrupts with the XIVE
     interrupt controller

   - support decrement register migration

   - various cleanups and bugfixes.

  s390:

   - Cornelia Huck passed maintainership to Janosch Frank

   - exitless interrupts for emulated devices

   - cleanup of cpuflag handling

   - kvm_stat counter improvements

   - VSIE improvements

   - mm cleanup

  x86:

   - hypervisor part of SEV

   - UMIP, RDPID, and MSR_SMI_COUNT emulation

   - paravirtualized TLB shootdown using the new KVM_VCPU_PREEMPTED bit

   - allow guests to see TOPOEXT, GFNI, VAES, VPCLMULQDQ, and more
     AVX512 features

   - show vcpu id in its anonymous inode name

   - many fixes and cleanups

   - per-VCPU MSR bitmaps (already merged through x86/pti branch)

   - stable KVM clock when nesting on Hyper-V (merged through
     x86/hyperv)"

* tag 'kvm-4.16-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (197 commits)
  KVM: PPC: Book3S: Add MMIO emulation for VMX instructions
  KVM: PPC: Book3S HV: Branch inside feature section
  KVM: PPC: Book3S HV: Make HPT resizing work on POWER9
  KVM: PPC: Book3S HV: Fix handling of secondary HPTEG in HPT resizing code
  KVM: PPC: Book3S PR: Fix broken select due to misspelling
  KVM: x86: don't forget vcpu_put() in kvm_arch_vcpu_ioctl_set_sregs()
  KVM: PPC: Book3S PR: Fix svcpu copying with preemption enabled
  KVM: PPC: Book3S HV: Drop locks before reading guest memory
  kvm: x86: remove efer_reload entry in kvm_vcpu_stat
  KVM: x86: AMD Processor Topology Information
  x86/kvm/vmx: do not use vm-exit instruction length for fast MMIO when running nested
  kvm: embed vcpu id to dentry of vcpu anon inode
  kvm: Map PFN-type memory regions as writable (if possible)
  x86/kvm: Make it compile on 32bit and with HYPYERVISOR_GUEST=n
  KVM: arm/arm64: Fixup userspace irqchip static key optimization
  KVM: arm/arm64: Fix userspace_irqchip_in_use counting
  KVM: arm/arm64: Fix incorrect timer_is_pending logic
  MAINTAINERS: update KVM/s390 maintainers
  MAINTAINERS: add Halil as additional vfio-ccw maintainer
  MAINTAINERS: add David as a reviewer for KVM/s390
  ...
2018-02-10 13:16:35 -08:00
Linus Torvalds
c013632192 2nd set of arm64 updates for 4.16:
Spectre v1 mitigation:
 - back-end version of array_index_mask_nospec()
 - masking of the syscall number to restrict speculation through the
   syscall table
 - masking of __user pointers prior to deference in uaccess routines
 
 Spectre v2 mitigation update:
 - using the new firmware SMC calling convention specification update
 - removing the current PSCI GET_VERSION firmware call mitigation as
   vendors are deploying new SMCCC-capable firmware
 - additional branch predictor hardening for synchronous exceptions and
   interrupts while in user mode
 
 Meltdown v3 mitigation update for Cavium Thunder X: unaffected but
 hardware erratum gets in the way. The kernel now starts with the page
 tables mapped as global and switches to non-global if kpti needs to be
 enabled.
 
 Other:
 - Theoretical trylock bug fixed
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEE5RElWfyWxS+3PLO2a9axLQDIXvEFAlp8lqcACgkQa9axLQDI
 XvH2lxAAnsYqthpGQ11MtDJB+/UiBAFkg9QWPDkwrBDvNhgpll+J0VQuCN1QJ2GX
 qQ8rkv8uV+y4Fqr8hORGJy5At+0aI63ZCJ72RGkZTzJAtbFbFGIDHP7RhAEIGJBS
 Lk9kDZ7k39wLEx30UXIFYTTVzyHar397TdI7vkTcngiTzZ8MdFATfN/hiKO906q3
 14pYnU9Um4aHUdcJ+FocL3dxvdgniuuMBWoNiYXyOCZXjmbQOnDNU2UrICroV8lS
 mB+IHNEhX1Gl35QzNBtC0ET+aySfHBMJmM5oln+uVUljIGx6En1WLj6mrHYcx8U2
 rIBm5qO/X/4iuzYPGkxwQtpjq3wPYxsSUnMdKJrsUZqAfy2QeIhFx6XUtJsZPB2J
 /lgls5xSXMOS7oiOQtmVjcDLBURDmYXGwljXR4n4jLm4CT1V9qSLcKHu1gdFU9Mq
 VuMUdPOnQub1vqKndi154IoYDTo21jAib2ktbcxpJfSJnDYoit4Gtnv7eWY+M3Pd
 Toaxi8htM2HSRwbvslHYGW8ZcVpI79Jit+ti7CsFg7m9Lvgs0zxcnNui4uPYDymT
 jh2JYxuirIJbX9aGGhnmkNhq9REaeZJg9LA2JM8S77FCHN3bnlSdaG6wy899J6EI
 lK4anCuPQKKKhUia/dc1MeKwrmmC18EfPyGUkOzywg/jGwGCmZM=
 =Y0TT
 -----END PGP SIGNATURE-----

Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull more arm64 updates from Catalin Marinas:
 "As I mentioned in the last pull request, there's a second batch of
  security updates for arm64 with mitigations for Spectre/v1 and an
  improved one for Spectre/v2 (via a newly defined firmware interface
  API).

  Spectre v1 mitigation:

   - back-end version of array_index_mask_nospec()

   - masking of the syscall number to restrict speculation through the
     syscall table

   - masking of __user pointers prior to deference in uaccess routines

  Spectre v2 mitigation update:

   - using the new firmware SMC calling convention specification update

   - removing the current PSCI GET_VERSION firmware call mitigation as
     vendors are deploying new SMCCC-capable firmware

   - additional branch predictor hardening for synchronous exceptions
     and interrupts while in user mode

  Meltdown v3 mitigation update:

    - Cavium Thunder X is unaffected but a hardware erratum gets in the
      way. The kernel now starts with the page tables mapped as global
      and switches to non-global if kpti needs to be enabled.

  Other:

   - Theoretical trylock bug fixed"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (38 commits)
  arm64: Kill PSCI_GET_VERSION as a variant-2 workaround
  arm64: Add ARM_SMCCC_ARCH_WORKAROUND_1 BP hardening support
  arm/arm64: smccc: Implement SMCCC v1.1 inline primitive
  arm/arm64: smccc: Make function identifiers an unsigned quantity
  firmware/psci: Expose SMCCC version through psci_ops
  firmware/psci: Expose PSCI conduit
  arm64: KVM: Add SMCCC_ARCH_WORKAROUND_1 fast handling
  arm64: KVM: Report SMCCC_ARCH_WORKAROUND_1 BP hardening support
  arm/arm64: KVM: Turn kvm_psci_version into a static inline
  arm/arm64: KVM: Advertise SMCCC v1.1
  arm/arm64: KVM: Implement PSCI 1.0 support
  arm/arm64: KVM: Add smccc accessors to PSCI code
  arm/arm64: KVM: Add PSCI_VERSION helper
  arm/arm64: KVM: Consolidate the PSCI include files
  arm64: KVM: Increment PC after handling an SMC trap
  arm: KVM: Fix SMCCC handling of unimplemented SMC/HVC calls
  arm64: KVM: Fix SMCCC handling of unimplemented SMC/HVC calls
  arm64: entry: Apply BP hardening for suspicious interrupts from EL0
  arm64: entry: Apply BP hardening for high-priority synchronous exceptions
  arm64: futex: Mask __user pointers prior to dereference
  ...
2018-02-08 10:44:25 -08:00
Marc Zyngier
a4097b3511 arm/arm64: KVM: Turn kvm_psci_version into a static inline
We're about to need kvm_psci_version in HYP too. So let's turn it
into a static inline, and pass the kvm structure as a second
parameter (so that HYP can do a kern_hyp_va on it).

Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-02-06 22:54:03 +00:00
Marc Zyngier
09e6be12ef arm/arm64: KVM: Advertise SMCCC v1.1
The new SMC Calling Convention (v1.1) allows for a reduced overhead
when calling into the firmware, and provides a new feature discovery
mechanism.

Make it visible to KVM guests.

Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-02-06 22:54:01 +00:00
Marc Zyngier
58e0b2239a arm/arm64: KVM: Implement PSCI 1.0 support
PSCI 1.0 can be trivially implemented by providing the FEATURES
call on top of PSCI 0.2 and returning 1.0 as the PSCI version.

We happily ignore everything else, as they are either optional or
are clarifications that do not require any additional change.

PSCI 1.0 is now the default until we decide to add a userspace
selection API.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-02-06 22:53:59 +00:00
Marc Zyngier
d0a144f12a arm/arm64: KVM: Add PSCI_VERSION helper
As we're about to trigger a PSCI version explosion, it doesn't
hurt to introduce a PSCI_VERSION helper that is going to be
used everywhere.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-02-06 22:53:56 +00:00
Marc Zyngier
1a2fb94e6a arm/arm64: KVM: Consolidate the PSCI include files
As we're about to update the PSCI support, and because I'm lazy,
let's move the PSCI include file to include/kvm so that both
ARM architectures can find it.

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-02-06 22:53:54 +00:00
Radim Krčmář
7bf14c28ee Merge branch 'x86/hyperv' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Topic branch for stable KVM clockource under Hyper-V.

Thanks to Christoffer Dall for resolving the ARM conflict.
2018-02-01 15:04:17 +01:00
Christoffer Dall
4c60e360d6 KVM: arm/arm64: Provide a get_input_level for the arch timer
The VGIC can now support the life-cycle of mapped level-triggered
interrupts, and we no longer have to read back the timer state on every
exit from the VM if we had an asserted timer interrupt signal, because
the VGIC already knows if we hit the unlikely case where the guest
disables the timer without ACKing the virtual timer interrupt.

This means we rework a bit of the code to factor out the functionality
to snapshot the timer state from vtimer_save_state(), and we can reuse
this functionality in the sync path when we have an irqchip in
userspace, and also to support our implementation of the
get_input_level() function for the timer.

This change also means that we can no longer rely on the timer's view of
the interrupt line to set the active state, because we no longer
maintain this state for mapped interrupts when exiting from the guest.
Instead, we only set the active state if the virtual interrupt is
active, and otherwise we simply let the timer fire again and raise the
virtual interrupt from the ISR.

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2018-01-02 10:05:46 +01:00
Christoffer Dall
b6909a659f KVM: arm/arm64: Support a vgic interrupt line level sample function
The GIC sometimes need to sample the physical line of a mapped
interrupt.  As we know this to be notoriously slow, provide a callback
function for devices (such as the timer) which can do this much faster
than talking to the distributor, for example by comparing a few
in-memory values.  Fall back to the good old method of poking the
physical GIC if no callback is provided.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2018-01-02 10:05:46 +01:00
Marc Zyngier
f384dcfe4d KVM: arm/arm64: timer: Don't set irq as forwarded if no usable GIC
If we don't have a usable GIC, do not try to set the vcpu affinity
as this is guaranteed to fail.

Reported-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Tested-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-12-18 10:53:23 +01:00
Christoffer Dall
ec6449a9c2 KVM: arm/arm64: Don't enable/disable physical timer access on VHE
After the timer optimization rework we accidentally end up calling
physical timer enable/disable functions on VHE systems, which is neither
needed nor correct, since the CNTHCTL_EL2 register format is
different when HCR_EL2.E2H is set.

The CNTHCTL_EL2 is initialized when CPUs become online in
kvm_timer_init_vhe() and we don't have to call these functions on VHE
systems, which also allows us to inline the non-VHE functionality.

Reported-by: Jintack Lim <jintack@cs.columbia.edu>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-11-29 16:46:09 +01:00
Marc Zyngier
df9ba95993 KVM: arm/arm64: GICv4: Use the doorbell interrupt as an unblocking source
The doorbell interrupt is only useful if the vcpu is blocked on WFI.
In all other cases, recieving a doorbell interrupt is just a waste
of cycles.

So let's only enable the doorbell if a vcpu is getting blocked,
and disable it when it is unblocked. This is very similar to
what we're doing for the background timer.

Reviewed-by: Christoffer Dall <cdall@linaro.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-11-10 09:43:22 +01:00
Marc Zyngier
196b136498 KVM: arm/arm64: GICv4: Wire mapping/unmapping of VLPIs in VFIO irq bypass
Let's use the irq bypass mechanism also used for x86 posted interrupts
to intercept the virtual PCIe endpoint configuration and establish our
LPI->VLPI mapping.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-11-10 09:28:52 +01:00
Marc Zyngier
74fe55dc9a KVM: arm/arm64: GICv4: Add init/teardown of the per-VM vPE irq domain
In order to control the GICv4 view of virtual CPUs, we rely
on an irqdomain allocated for that purpose. Let's add a couple
of helpers to that effect.

At the same time, the vgic data structures gain new fields to
track all this... erm... wonderful stuff.

The way we hook into the vgic init is slightly convoluted. We
need the vgic to be initialized (in order to guarantee that
the number of vcpus is now fixed), and we must have a vITS
(otherwise this is all very pointless). So we end-up calling
the init from both vgic_init and vgic_its_create.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-11-10 09:06:56 +01:00
Marc Zyngier
e7c4805924 KVM: arm/arm64: GICv4: Add property field and per-VM predicate
Add a new has_gicv4 field in the global VGIC state that indicates
whether the HW is GICv4 capable, as a per-VM predicate indicating
if there is a possibility for a VM to support direct injection
(the above being true and the VM having an ITS).

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-11-10 09:06:45 +01:00
Eric Auger
47bbd31f74 KVM: arm/arm64: vgic: restructure kvm_vgic_(un)map_phys_irq
We want to reuse the core of the map/unmap functions for IRQ
forwarding. Let's move the computation of the hwirq in
kvm_vgic_map_phys_irq and pass the linux IRQ as parameter.
the host_irq is added to struct vgic_irq.

We introduce kvm_vgic_map/unmap_irq which take a struct vgic_irq
handle as a parameter.

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-11-06 17:20:19 +01:00
Christoffer Dall
1c88ab7ec8 KVM: arm/arm64: Rework kvm_timer_should_fire
kvm_timer_should_fire() can be called in two different situations from
the kvm_vcpu_block().

The first case is before calling kvm_timer_schedule(), used for wait
polling, and in this case the VCPU thread is running and the timer state
is loaded onto the hardware so all we have to do is check if the virtual
interrupt lines are asserted, becasue the timer interrupt handler
functions will raise those lines as appropriate.

The second case is inside the wait loop of kvm_vcpu_block(), where we
have already called kvm_timer_schedule() and therefore the hardware will
be disabled and the software view of the timer state is up to date
(timer->loaded is false), and so we can simply check if the timer should
fire by looking at the software state.

Signed-off-by: Christoffer Dall <cdall@linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
2017-11-06 16:23:17 +01:00
Christoffer Dall
7e90c8e570 KVM: arm/arm64: Get rid of kvm_timer_flush_hwstate
Now when both the vtimer and the ptimer when using both the in-kernel
vgic emulation and a userspace IRQ chip are driven by the timer signals
and at the vcpu load/put boundaries, instead of recomputing the timer
state at every entry/exit to/from the guest, we can get entirely rid of
the flush hwstate function.

Signed-off-by: Christoffer Dall <cdall@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
2017-11-06 16:23:16 +01:00
Christoffer Dall
b103cc3f10 KVM: arm/arm64: Avoid timer save/restore in vcpu entry/exit
We don't need to save and restore the hardware timer state and examine
if it generates interrupts on on every entry/exit to the guest.  The
timer hardware is perfectly capable of telling us when it has expired
by signaling interrupts.

When taking a vtimer interrupt in the host, we don't want to mess with
the timer configuration, we just want to forward the physical interrupt
to the guest as a virtual interrupt.  We can use the split priority drop
and deactivate feature of the GIC to do this, which leaves an EOI'ed
interrupt active on the physical distributor, making sure we don't keep
taking timer interrupts which would prevent the guest from running.  We
can then forward the physical interrupt to the VM using the HW bit in
the LR of the GIC, like we do already, which lets the guest directly
deactivate both the physical and virtual timer simultaneously, allowing
the timer hardware to exit the VM and generate a new physical interrupt
when the timer output is again asserted later on.

We do need to capture this state when migrating VCPUs between physical
CPUs, however, which we use the vcpu put/load functions for, which are
called through preempt notifiers whenever the thread is scheduled away
from the CPU or called directly if we return from the ioctl to
userspace.

One caveat is that we have to save and restore the timer state in both
kvm_timer_vcpu_[put/load] and kvm_timer_[schedule/unschedule], because
we can have the following flows:

  1. kvm_vcpu_block
  2. kvm_timer_schedule
  3. schedule
  4. kvm_timer_vcpu_put (preempt notifier)
  5. schedule (vcpu thread gets scheduled back)
  6. kvm_timer_vcpu_load (preempt notifier)
  7. kvm_timer_unschedule

And a version where we don't actually call schedule:

  1. kvm_vcpu_block
  2. kvm_timer_schedule
  7. kvm_timer_unschedule

Since kvm_timer_[schedule/unschedule] may not be followed by put/load,
but put/load also may be called independently, we call the timer
save/restore functions from both paths.  Since they rely on the loaded
flag to never save/restore when unnecessary, this doesn't cause any
harm, and we ensure that all invokations of either set of functions work
as intended.

An added benefit beyond not having to read and write the timer sysregs
on every entry and exit is that we no longer have to actively write the
active state to the physical distributor, because we configured the
irq for the vtimer to only get a priority drop when handling the
interrupt in the GIC driver (we called irq_set_vcpu_affinity()), and
the interrupt stays active after firing on the host.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-11-06 16:23:14 +01:00
Christoffer Dall
f2a2129e0a KVM: arm/arm64: Use separate timer for phys timer emulation
We were using the same hrtimer for emulating the physical timer and for
making sure a blocking VCPU thread would be eventually woken up.  That
worked fine in the previous arch timer design, but as we are about to
actually use the soft timer expire function for the physical timer
emulation, change the logic to use a dedicated hrtimer.

This has the added benefit of not having to cancel any work in the sync
path, which in turn allows us to run the flush and sync with IRQs
disabled.

Note that the hrtimer used to program the host kernel's timer to
generate an exit from the guest when the emulated physical timer fires
never has to inject any work, and to share the soft_timer_cancel()
function with the bg_timer, we change the function to only cancel any
pending work if the pointer to the work struct is not null.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-11-06 16:23:12 +01:00
Christoffer Dall
14d61fa98f KVM: arm/arm64: Rename soft timer to bg_timer
As we are about to introduce a separate hrtimer for the physical timer,
call this timer bg_timer, because we refer to this timer as the
background timer in the code and comments elsewhere.

Signed-off-by: Christoffer Dall <cdall@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
2017-11-06 16:23:11 +01:00
Christoffer Dall
8409a06f2a KVM: arm/arm64: Make timer_arm and timer_disarm helpers more generic
We are about to add an additional soft timer to the arch timer state for
a VCPU and would like to be able to reuse the functions to program and
cancel a timer, so we make them slightly more generic and rename to make
it more clear that these functions work on soft timers and not the
hardware resource that this code is managing.

The armed flag on the timer state is only used to assert a condition,
and we don't rely on this assertion in any meaningful way, so we can
simply get rid of this flack and slightly reduce complexity.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-11-06 16:23:11 +01:00
Andrew Jones
d9f89b4e92 KVM: arm/arm64: PMU: Fix overflow interrupt injection
kvm_pmu_overflow_set() is called from perf's interrupt handler,
making the call of kvm_vgic_inject_irq() from it introduced with
"KVM: arm/arm64: PMU: remove request-less vcpu kick" a really bad
idea, as it's quite easy to try and retake a lock that the
interrupted context is already holding. The fix is to use a vcpu
kick, leaving the interrupt injection to kvm_pmu_sync_hwstate(),
like it was doing before the refactoring. We don't just revert,
though, because before the kick was request-less, leaving the vcpu
exposed to the request-less vcpu kick race, and also because the
kick was used unnecessarily from register access handlers.

Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-07-25 14:18:01 +01:00