Commit Graph

44 Commits

Author SHA1 Message Date
Bjorn Helgaas
75841d89f3 KVM: arm64: Fix typos
Fix typos, most reported by "codespell arch/arm64".  Only touches comments,
no code changes.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: James Morse <james.morse@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Zenghui Yu <yuzenghui@huawei.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: kvmarm@lists.linux.dev
Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20240103231605.1801364-6-helgaas@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-24 09:13:33 +00:00
Marc Zyngier
111903d1f5 KVM: arm64: nv: Hoist vcpu_has_nv() into is_hyp_ctxt()
A rather common idiom when writing NV code as part of KVM is
to have things such has:

	if (vcpu_has_nv(vcpu) && is_hyp_ctxt(vcpu)) {
		[...]
	}

to check that we are in a hyp-related context. The second part of
the conjunction would be enough, but the first one contains a
static key that allows the rest of the checkis to be elided when
in a non-NV environment.

Rewrite is_hyp_ctxt() to directly use vcpu_has_nv(). The result
is the same, and the code easier to read. The one occurence of
this that is already merged is rewritten in the process.

In order to avoid nasty cirtular dependencies between kvm_emulate.h
and kvm_nested.h, vcpu_has_feature() is itself hoisted into kvm_host.h,
at the cost of some #deferry...

Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2023-12-19 09:50:52 +00:00
Paolo Bonzini
45b890f768 KVM/arm64 updates for 6.7
- Generalized infrastructure for 'writable' ID registers, effectively
    allowing userspace to opt-out of certain vCPU features for its guest
 
  - Optimization for vSGI injection, opportunistically compressing MPIDR
    to vCPU mapping into a table
 
  - Improvements to KVM's PMU emulation, allowing userspace to select
    the number of PMCs available to a VM
 
  - Guest support for memory operation instructions (FEAT_MOPS)
 
  - Cleanups to handling feature flags in KVM_ARM_VCPU_INIT, squashing
    bugs and getting rid of useless code
 
  - Changes to the way the SMCCC filter is constructed, avoiding wasted
    memory allocations when not in use
 
  - Load the stage-2 MMU context at vcpu_load() for VHE systems, reducing
    the overhead of errata mitigations
 
  - Miscellaneous kernel and selftest fixes
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Merge tag 'kvmarm-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 updates for 6.7

 - Generalized infrastructure for 'writable' ID registers, effectively
   allowing userspace to opt-out of certain vCPU features for its guest

 - Optimization for vSGI injection, opportunistically compressing MPIDR
   to vCPU mapping into a table

 - Improvements to KVM's PMU emulation, allowing userspace to select
   the number of PMCs available to a VM

 - Guest support for memory operation instructions (FEAT_MOPS)

 - Cleanups to handling feature flags in KVM_ARM_VCPU_INIT, squashing
   bugs and getting rid of useless code

 - Changes to the way the SMCCC filter is constructed, avoiding wasted
   memory allocations when not in use

 - Load the stage-2 MMU context at vcpu_load() for VHE systems, reducing
   the overhead of errata mitigations

 - Miscellaneous kernel and selftest fixes
2023-10-31 16:37:07 -04:00
Oliver Upton
54b44ad26c Merge branch kvm-arm64/sgi-injection into kvmarm/next
* kvm-arm64/sgi-injection:
  : vSGI injection improvements + fixes, courtesy Marc Zyngier
  :
  : Avoid linearly searching for vSGI targets using a compressed MPIDR to
  : index a cache. While at it, fix some egregious bugs in KVM's mishandling
  : of vcpuid (user-controlled value) and vcpu_idx.
  KVM: arm64: Clarify the ordering requirements for vcpu/RD creation
  KVM: arm64: vgic-v3: Optimize affinity-based SGI injection
  KVM: arm64: Fast-track kvm_mpidr_to_vcpu() when mpidr_data is available
  KVM: arm64: Build MPIDR to vcpu index cache at runtime
  KVM: arm64: Simplify kvm_vcpu_get_mpidr_aff()
  KVM: arm64: Use vcpu_idx for invalidation tracking
  KVM: arm64: vgic: Use vcpu_idx for the debug information
  KVM: arm64: vgic-v2: Use cpuid from userspace as vcpu_id
  KVM: arm64: vgic-v3: Refactor GICv3 SGI generation
  KVM: arm64: vgic-its: Treat the collection target address as a vcpu_id
  KVM: arm64: vgic: Make kvm_vgic_inject_irq() take a vcpu pointer

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-10-30 20:19:13 +00:00
Marc Zyngier
9404673293 KVM: arm64: timers: Correctly handle TGE flip with CNTPOFF_EL2
Contrary to common belief, HCR_EL2.TGE has a direct and immediate
effect on the way the EL0 physical counter is offset. Flipping
TGE from 1 to 0 while at EL2 immediately changes the way the counter
compared to the CVAL limit.

This means that we cannot directly save/restore the guest's view of
CVAL, but that we instead must treat it as if CNTPOFF didn't exist.
Only in the world switch, once we figure out that we do have CNTPOFF,
can we must the offset back and forth depending on the polarity of
TGE.

Fixes: 2b4825a869 ("KVM: arm64: timers: Use CNTPOFF_EL2 to offset the physical timer")
Reported-by: Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com>
Tested-by: Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2023-10-12 16:55:21 +01:00
Marc Zyngier
9a0a75d3cc KVM: arm64: vgic: Make kvm_vgic_inject_irq() take a vcpu pointer
Passing a vcpu_id to kvm_vgic_inject_irq() is silly for two reasons:

- we often confuse vcpu_id and vcpu_idx
- we eventually have to convert it back to a vcpu
- we can't count

Instead, pass a vcpu pointer, which is unambiguous. A NULL vcpu
is also allowed for interrupts that are not private to a vcpu
(such as SPIs).

Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230927090911.3355209-2-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-09-30 18:15:43 +00:00
Oliver Upton
3d4b2a4cdd KVM: arm64: Remove unused return value from kvm_reset_vcpu()
Get rid of the return value for kvm_reset_vcpu() as there are no longer
any cases where it returns a nonzero value.

Link: https://lore.kernel.org/r/20230920195036.1169791-8-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-09-21 18:13:29 +00:00
Marc Zyngier
fe769e6c1f KVM: arm64: timers: Use CNTHCTL_EL2 when setting non-CNTKCTL_EL1 bits
It recently appeared that, when running VHE, there is a notable
difference between using CNTKCTL_EL1 and CNTHCTL_EL2, despite what
the architecture documents:

- When accessed from EL2, bits [19:18] and [16:10] of CNTKCTL_EL1 have
  the same assignment as CNTHCTL_EL2
- When accessed from EL1, bits [19:18] and [16:10] are RES0

It is all OK, until you factor in NV, where the EL2 guest runs at EL1.
In this configuration, CNTKCTL_EL11 doesn't trap, nor ends up in
the VNCR page. This means that any write from the guest affecting
CNTHCTL_EL2 using CNTKCTL_EL1 ends up losing some state. Not good.

The fix it obvious: don't use CNTKCTL_EL1 if you want to change bits
that are not part of the EL1 definition of CNTKCTL_EL1, and use
CNTHCTL_EL2 instead. This doesn't change anything for a bare-metal OS,
and fixes it when running under NV. The NV hypervisor will itself
have to work harder to merge the two accessors.

Note that there is a pending update to the architecture to address
this issue by making the affected bits UNKNOWN when CNTKCTL_EL1 is
used from EL2 with VHE enabled.

Fixes: c605ee2450 ("KVM: arm64: timers: Allow physical offset without CNTPOFF_EL2")
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org # v6.4
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20230627140557.544885-1-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-07-11 19:28:30 +00:00
Dan Carpenter
21e87daece KVM: arm64: timers: Fix resource leaks in kvm_timer_hyp_init()
Smatch detected this bug:
    arch/arm64/kvm/arch_timer.c:1425 kvm_timer_hyp_init()
    warn: missing unwind goto?

There are two resources to be freed the vtimer and ptimer.  The
line that Smatch complains about should free the vtimer first
before returning and then after that cleanup code should free
the ptimer.

I've added a out_free_ptimer_irq to free the ptimer and renamed
the existing label to out_free_vtimer_irq.

Fixes: 9e01dc76be ("KVM: arm/arm64: arch_timer: Assign the phys timer on VHE systems")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/72fffc35-7669-40b1-9d14-113c43269cf3@kili.mountain
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-06-13 12:06:05 +00:00
Marc Zyngier
b22498c484 Merge branch kvm-arm64/timer-vm-offsets into kvmarm-master/next
* kvm-arm64/timer-vm-offsets: (21 commits)
  : .
  : This series aims at satisfying multiple goals:
  :
  : - allow a VMM to atomically restore a timer offset for a whole VM
  :   instead of updating the offset each time a vcpu get its counter
  :   written
  :
  : - allow a VMM to save/restore the physical timer context, something
  :   that we cannot do at the moment due to the lack of offsetting
  :
  : - provide a framework that is suitable for NV support, where we get
  :   both global and per timer, per vcpu offsetting, and manage
  :   interrupts in a less braindead way.
  :
  : Conflict resolution involves using the new per-vcpu config lock instead
  : of the home-grown timer lock.
  : .
  KVM: arm64: Handle 32bit CNTPCTSS traps
  KVM: arm64: selftests: Augment existing timer test to handle variable offset
  KVM: arm64: selftests: Deal with spurious timer interrupts
  KVM: arm64: selftests: Add physical timer registers to the sysreg list
  KVM: arm64: nv: timers: Support hyp timer emulation
  KVM: arm64: nv: timers: Add a per-timer, per-vcpu offset
  KVM: arm64: Document KVM_ARM_SET_CNT_OFFSETS and co
  KVM: arm64: timers: Abstract the number of valid timers per vcpu
  KVM: arm64: timers: Fast-track CNTPCT_EL0 trap handling
  KVM: arm64: Elide kern_hyp_va() in VHE-specific parts of the hypervisor
  KVM: arm64: timers: Move the timer IRQs into arch_timer_vm_data
  KVM: arm64: timers: Abstract per-timer IRQ access
  KVM: arm64: timers: Rationalise per-vcpu timer init
  KVM: arm64: timers: Allow save/restoring of the physical timer
  KVM: arm64: timers: Allow userspace to set the global counter offset
  KVM: arm64: Expose {un,}lock_all_vcpus() to the rest of KVM
  KVM: arm64: timers: Allow physical offset without CNTPOFF_EL2
  KVM: arm64: timers: Use CNTPOFF_EL2 to offset the physical timer
  arm64: Add HAS_ECV_CNTPOFF capability
  arm64: Add CNTPOFF_EL2 register definition
  ...

Signed-off-by: Marc Zyngier <maz@kernel.org>
2023-04-21 09:36:40 +01:00
Marc Zyngier
81dc9504a7 KVM: arm64: nv: timers: Support hyp timer emulation
Emulating EL2 also means emulating the EL2 timers. To do so, we expand
our timer framework to deal with at most 4 timers. At any given time,
two timers are using the HW timers, and the two others are purely
emulated.

The role of deciding which is which at any given time is left to a
mapping function which is called every time we need to make such a
decision.

Reviewed-by: Colton Lewis <coltonlewis@google.com>
Co-developed-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230330174800.2677007-18-maz@kernel.org
2023-03-30 19:01:10 +01:00
Marc Zyngier
1e0eec09d4 KVM: arm64: nv: timers: Add a per-timer, per-vcpu offset
Being able to set a global offset isn't enough.

With NV, we also need to a per-vcpu, per-timer offset (for example,
CNTVCT_EL0 being offset by CNTVOFF_EL2).

Use a similar method as the VM-wide offset to have a timer point
to the shadow register that contains the offset value.

Reviewed-by: Colton Lewis <coltonlewis@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230330174800.2677007-17-maz@kernel.org
2023-03-30 19:01:10 +01:00
Marc Zyngier
476fcd4b7b KVM: arm64: timers: Abstract the number of valid timers per vcpu
We so far have a pretty fixed number of timers to take care of.
This is about to change as NV brings another two into the
picture, and we must be careful not to try and emulate non-valid
timers in a given VM.

For this, abstract the number of timers for a given vcpu behind
an accessor, which helpfully returns a constant for now.

Reviewed-by: Colton Lewis <coltonlewis@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230330174800.2677007-15-maz@kernel.org
2023-03-30 19:01:10 +01:00
Marc Zyngier
8a5eb2d210 KVM: arm64: timers: Move the timer IRQs into arch_timer_vm_data
Having the timer IRQs duplicated into each vcpu isn't great, and
becomes absolutely awful with NV. So let's move these into
the per-VM arch_timer_vm_data structure.

This simplifies a lot of code, but requires us to introduce a
mutex so that we can reason about userspace trying to change
an interrupt number while another vcpu is running, something
that wasn't really well handled so far.

Reviewed-by: Colton Lewis <coltonlewis@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230330174800.2677007-12-maz@kernel.org
2023-03-30 19:01:10 +01:00
Marc Zyngier
33c549460e KVM: arm64: timers: Abstract per-timer IRQ access
As we are about to move the location of the per-timer IRQ into
the VM structure, abstract the location of the IRQ behind an
accessor. This will make the repainting sligntly less painful.

Reviewed-by: Colton Lewis <coltonlewis@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230330174800.2677007-11-maz@kernel.org
2023-03-30 19:01:10 +01:00
Marc Zyngier
5591805d2c KVM: arm64: timers: Rationalise per-vcpu timer init
The way we initialise our timer contexts may be satisfactory
for two timers, but will be getting pretty annoying with four.

Cleanup the whole thing by removing the code duplication and
getting rid of unused IRQ configuration elements.

Reviewed-by: Colton Lewis <coltonlewis@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230330174800.2677007-10-maz@kernel.org
2023-03-30 19:01:10 +01:00
Marc Zyngier
30ec7997d1 KVM: arm64: timers: Allow userspace to set the global counter offset
And this is the moment you have all been waiting for: setting the
counter offset from userspace.

We expose a brand new capability that reports the ability to set
the offset for both the virtual and physical sides.

In keeping with the architecture, the offset is expressed as
a delta that is substracted from the physical counter value.

Once this new API is used, there is no going back, and the counters
cannot be written to to set the offsets implicitly (the writes
are instead ignored).

Reviewed-by: Colton Lewis <coltonlewis@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230330174800.2677007-8-maz@kernel.org
2023-03-30 19:01:10 +01:00
Marc Zyngier
c605ee2450 KVM: arm64: timers: Allow physical offset without CNTPOFF_EL2
CNTPOFF_EL2 is awesome, but it is mostly vapourware, and no publicly
available implementation has it. So for the common mortals, let's
implement the emulated version of this thing.

It means trapping accesses to the physical counter and timer, and
emulate some of it as necessary.

As for CNTPOFF_EL2, nobody sets the offset yet.

Reviewed-by: Colton Lewis <coltonlewis@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230330174800.2677007-6-maz@kernel.org
2023-03-30 19:01:09 +01:00
Marc Zyngier
2b4825a869 KVM: arm64: timers: Use CNTPOFF_EL2 to offset the physical timer
With ECV and CNTPOFF_EL2, it is very easy to offer an offset for
the physical timer. So let's do just that.

Nothing can set the offset yet, so this should have no effect
whatsoever (famous last words...).

Reviewed-by: Colton Lewis <coltonlewis@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230330174800.2677007-5-maz@kernel.org
2023-03-30 19:01:09 +01:00
Marc Zyngier
0d0ae656b7 KVM: arm64: timers: Use a per-vcpu, per-timer accumulator for fractional ns
Instead of accumulating the fractional ns value generated every time
we compute a ns delta in a global variable, use a per-vcpu, per-timer
variable. This keeps the fractional ns local to the timer instead of
contributing to any odd, unrelated timer.

Reviewed-by: Colton Lewis <coltonlewis@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230330174800.2677007-2-maz@kernel.org
2023-03-30 19:01:09 +01:00
Marc Zyngier
47053904e1 KVM: arm64: timers: Convert per-vcpu virtual offset to a global value
Having a per-vcpu virtual offset is a pain. It needs to be synchronized
on each update, and expands badly to a setup where different timers can
have different offsets, or have composite offsets (as with NV).

So let's start by replacing the use of the CNTVOFF_EL2 shadow register
(which we want to reclaim for NV anyway), and make the virtual timer
carry a pointer to a VM-wide offset.

This simplifies the code significantly. It also addresses two terrible bugs:

- The use of CNTVOFF_EL2 leads to some nice offset corruption
  when the sysreg gets reset, as reported by Joey.

- The kvm mutex is taken from a vcpu ioctl, which goes against
  the locking rules...

Reported-by: Joey Gouly <joey.gouly@arm.com>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230224173915.GA17407@e124191.cambridge.arm.com
Tested-by: Joey Gouly <joey.gouly@arm.com>
Link: https://lore.kernel.org/r/20230224191640.3396734-1-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-03-11 02:00:40 -08:00
Oliver Upton
1b915210d9 Merge branch kvm-arm64/nv-timer-improvements into kvmarm/next
* kvm-arm64/nv-timer-improvements:
  : Timer emulation improvements, courtesy of Marc Zyngier.
  :
  :  - Avoid re-arming an hrtimer for a guest timer that is already pending
  :
  :  - Only reload the affected timer context when emulating a sysreg access
  :    instead of both the virtual/physical timers.
  KVM: arm64: timers: Don't BUG() on unhandled timer trap
  KVM: arm64: Reduce overhead of trapped timer sysreg accesses
  KVM: arm64: Don't arm a hrtimer for an already pending timer

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-02-13 23:26:21 +00:00
Marc Zyngier
fc6ee952cf KVM: arm64: Reduce overhead of trapped timer sysreg accesses
Each read/write to a trapped timer system register results
in a whole kvm_timer_vcpu_put/load() cycle which affects all
of the timers, and a bit more.

There is no need for such a thing, and we can limit the impact
to the timer being affected, and only this one.

This drastically simplifies the emulated case, and limits the
damage for trapped accesses. This also brings some performance
back for NV.

Whilst we're at it, fix a comment that didn't quite capture why
we always set CNTVOFF_EL2 to 0 when disabling the virtual timer.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230112123829.458912-3-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-01-26 18:48:47 +00:00
Marc Zyngier
4d74ecfa64 KVM: arm64: Don't arm a hrtimer for an already pending timer
When fully emulating a timer, we back it with a hrtimer that is
armver on vcpu_load(). However, we do this even if the timer is
already pending.

This causes spurious interrupts to be taken, though the guest
doesn't observe them (the interrupt is already pending).

Although this is a waste of precious cycles, this isn't the
end of the world with the current state of KVM. However, this
can lead to a situation where a guest doesn't make forward
progress anymore with NV.

Fix it by checking that if the timer is already pending
before arming a new hrtimer. Also drop the hrtimer cancelling,
which is useless, by construction.

Reported-by: D Scott Phillips <scott@os.amperecomputing.com>
Fixes: bee038a674 ("KVM: arm/arm64: Rework the timer code to use a timer_map")
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230112123829.458912-2-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-01-26 18:48:47 +00:00
Sean Christopherson
8d20bd6381 KVM: x86: Unify pr_fmt to use module name for all KVM modules
Define pr_fmt using KBUILD_MODNAME for all KVM x86 code so that printks
use consistent formatting across common x86, Intel, and AMD code.  In
addition to providing consistent print formatting, using KBUILD_MODNAME,
e.g. kvm_amd and kvm_intel, allows referencing SVM and VMX (and SEV and
SGX and ...) as technologies without generating weird messages, and
without causing naming conflicts with other kernel code, e.g. "SEV: ",
"tdx: ", "sgx: " etc.. are all used by the kernel for non-KVM subsystems.

Opportunistically move away from printk() for prints that need to be
modified anyways, e.g. to drop a manual "kvm: " prefix.

Opportunistically convert a few SGX WARNs that are similarly modified to
WARN_ONCE; in the very unlikely event that the WARNs fire, odds are good
that they would fire repeatedly and spam the kernel log without providing
unique information in each print.

Note, defining pr_fmt yields undesirable results for code that uses KVM's
printk wrappers, e.g. vcpu_unimpl().  But, that's a pre-existing problem
as SVM/kvm_amd already defines a pr_fmt, and thankfully use of KVM's
wrappers is relatively limited in KVM x86 code.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Message-Id: <20221130230934.1014142-35-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-29 15:47:35 -05:00
Marc Zyngier
466d27e48d KVM: arm64: Simplify the CPUHP logic
For a number of historical reasons, the KVM/arm64 hotplug setup is pretty
complicated, and we have two extra CPUHP notifiers for vGIC and timers.

It looks pretty pointless, and gets in the way of further changes.
So let's just expose some helpers that can be called from the core
CPUHP callback, and get rid of everything else.

This gives us the opportunity to drop a useless notifier entry,
as well as tidy-up the timer enable/disable, which was a bit odd.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221130230934.1014142-17-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-29 15:41:04 -05:00
Marc Zyngier
dc94f89ae6 Merge branch kvm-arm64/burn-the-flags into kvmarm-master/next
* kvm-arm64/burn-the-flags:
  : .
  : Rework the per-vcpu flags to make them more manageable,
  : splitting them in different sets that have specific
  : uses:
  :
  : - configuration flags
  : - input to the world-switch
  : - state bookkeeping for the kernel itself
  :
  : The FP tracking is also simplified and tracked outside
  : of the flags as a separate state.
  : .
  KVM: arm64: Move the handling of !FP outside of the fast path
  KVM: arm64: Document why pause cannot be turned into a flag
  KVM: arm64: Reduce the size of the vcpu flag members
  KVM: arm64: Add build-time sanity checks for flags
  KVM: arm64: Warn when PENDING_EXCEPTION and INCREMENT_PC are set together
  KVM: arm64: Convert vcpu sysregs_loaded_on_cpu to a state flag
  KVM: arm64: Kill unused vcpu flags field
  KVM: arm64: Move vcpu WFIT flag to the state flag set
  KVM: arm64: Move vcpu ON_UNSUPPORTED_CPU flag to the state flag set
  KVM: arm64: Move vcpu SVE/SME flags to the state flag set
  KVM: arm64: Move vcpu debug/SPE/TRBE flags to the input flag set
  KVM: arm64: Move vcpu PC/Exception flags to the input flag set
  KVM: arm64: Move vcpu configuration flags into their own set
  KVM: arm64: Add three sets of flags to the vcpu state
  KVM: arm64: Add helpers to manipulate vcpu flags among a set
  KVM: arm64: Move FP state ownership from flag to a tristate
  KVM: arm64: Drop FP_FOREIGN_STATE from the hypervisor code

Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-06-29 10:30:10 +01:00
Marc Zyngier
eebc538d8e KVM: arm64: Move vcpu WFIT flag to the state flag set
The host kernel uses the WFIT flag to remember that a vcpu has used
this instruction and wake it up as required. Move it to the state
set, as nothing in the hypervisor uses this information.

Reviewed-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-06-29 10:23:23 +01:00
Marc Zyngier
efedd01de4 KVM: arm64: Warn if accessing timer pending state outside of vcpu context
A recurrent bug in the KVM/arm64 code base consists in trying to
access the timer pending state outside of the vcpu context, which
makes zero sense (the pending state only exists when the vcpu
is loaded).

In order to avoid more embarassing crashes and catch the offenders
red-handed, add a warning to kvm_arch_timer_get_input_level() and
return the state as non-pending. This avoids taking the system down,
and still helps tracking down silly bugs.

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220607131427.1164881-4-maz@kernel.org
2022-06-08 10:16:23 +01:00
Marc Zyngier
89f5074c50 KVM: arm64: Handle blocking WFIT instruction
When trapping a blocking WFIT instruction, take it into account when
computing the deadline of the background timer.

The state is tracked with a new vcpu flag, and is gated by a new
CPU capability, which isn't currently enabled.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220419182755.601427-6-maz@kernel.org
2022-04-20 13:24:45 +01:00
Marc Zyngier
daf85a5f6b KVM: arm64: Introduce kvm_counter_compute_delta() helper
Refactor kvm_timer_compute_delta() and extract a helper that
compute the delta (in ns) between a given timer and an arbitrary
value.

No functional change expected.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220419182755.601427-5-maz@kernel.org
2022-04-20 13:24:44 +01:00
Marc Zyngier
b57de4ffd7 KVM: arm64: Simplify kvm_cpu_has_pending_timer()
kvm_cpu_has_pending_timer() ends up checking all the possible
timers for a wake-up cause. However, we already check for
pending interrupts whenever we try to wake-up a vcpu, including
the timer interrupts.

Obviously, doing the same work twice is once too many. Reduce
this helper to almost nothing, but keep it around, as we are
going to make use of it soon.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220419182755.601427-4-maz@kernel.org
2022-04-20 13:24:44 +01:00
Sean Christopherson
d92a5d1c6c KVM: Add helpers to wake/query blocking vCPU
Add helpers to wake and query a blocking vCPU.  In addition to providing
nice names, the helpers reduce the probability of KVM neglecting to use
kvm_arch_vcpu_get_wait().

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211009021236.4122790-20-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08 04:24:54 -05:00
Sean Christopherson
91b99ea706 KVM: Rename kvm_vcpu_block() => kvm_vcpu_halt()
Rename kvm_vcpu_block() to kvm_vcpu_halt() in preparation for splitting
the actual "block" sequences into a separate helper (to be named
kvm_vcpu_block()).  x86 will use the standalone block-only path to handle
non-halt cases where the vCPU is not runnable.

Rename block_ns to halt_ns to match the new function name.

No functional change intended.

Reviewed-by: David Matlack <dmatlack@google.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211009021236.4122790-14-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08 04:24:51 -05:00
Marc Zyngier
46808a4cb8 KVM: Use 'unsigned long' as kvm_for_each_vcpu()'s index
Everywhere we use kvm_for_each_vpcu(), we use an int as the vcpu
index. Unfortunately, we're about to move rework the iterator,
which requires this to be upgrade to an unsigned long.

Let's bite the bullet and repaint all of it in one go.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Message-Id: <20211116160403.4074052-7-maz@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08 04:24:15 -05:00
Marc Zyngier
5f59229680 KVM: arm64: timer: Add support for SW-based deactivation
In order to deal with the lack of active state, we need to use
the mask/unmask primitives (after all, the active state is just an
additional mask on top of the normal one).

To avoid adding a bunch of ugly conditionals in the timer and vgic
code, let's use a timer-specific irqdomain to deal with the state
conversion. Yes, this is an unexpected use of irqdomains, but
there is no reason not to be just as creative as the designers
of the HW...

This involves overloading the vcpu_affinity, set_irqchip_state
and eoi callbacks so that the rest of the KVM code can continue
ignoring the oddities of the underlying platform.

Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-06-01 10:46:00 +01:00
Marc Zyngier
2f2f7e39db KVM: arm64: timer: Refactor IRQ configuration
As we are about to add some more things to the timer IRQ
configuration, move this code out of the main timer init code
into its own set of functions.

No functional changes.

Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-06-01 10:46:00 +01:00
Marc Zyngier
db75f1a33f KVM: arm64: vgic: move irq->get_input_level into an ops structure
We already have the option to attach a callback to an interrupt
to retrieve its pending state. As we are planning to expand this
facility, move this callback into its own data structure.

This will limit the size of individual interrupts as the ops
structures can be shared across multiple interrupts.

Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-06-01 10:45:59 +01:00
Alexandru Elisei
f16570ba47 KVM: arm64: arch_timer: Remove VGIC initialization check
kvm_timer_enable() is called in kvm_vcpu_first_run_init() after
kvm_vgic_map_resources() if the VGIC wasn't ready. kvm_vgic_map_resources()
is the only place where kvm->arch.vgic.ready is set to true.

For a v2 VGIC, kvm_vgic_map_resources() will attempt to initialize the VGIC
and set the initialized flag.

For a v3 VGIC, kvm_vgic_map_resources() will return an error code if the
VGIC isn't already initialized.

The end result is that if we've reached kvm_timer_enable(), the VGIC is
initialzed and ready and vgic_initialized() will always be true, so remove
this check.

Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
[maz: added comment about vgic initialisation, as suggested by Eric]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201201150157.223625-3-alexandru.elisei@arm.com
2020-12-23 16:43:12 +00:00
Marc Zyngier
41ce82f63c KVM: arm64: timers: Move timer registers to the sys_regs file
Move the timer gsisters to the sysreg file. This will further help when
they are directly changed by a nesting hypervisor in the VNCR page.

This requires moving the initialisation of the timer struct so that some
of the helpers (such as arch_timer_ctx_index) can work correctly at an
early stage.

Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-07-07 09:28:38 +01:00
Marc Zyngier
3c5ff0c60f KVM: arm64: timers: Rename kvm_timer_sync_hwstate to kvm_timer_sync_user
kvm_timer_sync_hwstate() has nothing to do with the timer HW state,
but more to do with the state of a userspace interrupt controller.
Change the suffix from _hwstate to_user, in keeping with the rest
of the code.

Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-07-07 09:28:38 +01:00
Paolo Bonzini
380609445c KVM/arm64 updates for Linux 5.8:
- Move the arch-specific code into arch/arm64/kvm
 - Start the post-32bit cleanup
 - Cherry-pick a few non-invasive pre-NV patches
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Merge tag 'kvmarm-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 updates for Linux 5.8:

- Move the arch-specific code into arch/arm64/kvm
- Start the post-32bit cleanup
- Cherry-pick a few non-invasive pre-NV patches
2020-06-01 04:26:27 -04:00
Marc Zyngier
c6fe89ff8b KVM: arm64: Simplify __kvm_timer_set_cntvoff implementation
Now that this function isn't constrained by the 32bit PCS,
let's simplify it by taking a single 64bit offset instead
of two 32bit parameters.

Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-05-16 15:04:18 +01:00
Marc Zyngier
9ed24f4b71 KVM: arm64: Move virt/kvm/arm to arch/arm64
Now that the 32bit KVM/arm host is a distant memory, let's move the
whole of the KVM/arm64 code into the arm64 tree.

As they said in the song: Welcome Home (Sanitarium).

Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200513104034.74741-1-maz@kernel.org
2020-05-16 15:03:59 +01:00