Commit graph

884 commits

Author SHA1 Message Date
Alexandru Elisei
14a34b30f1 KVM: arm64: Treat emulated TVAL TimerValue as a signed 32-bit integer
commit 4a267aa707 upstream.

According to the ARM ARM, registers CNT{P,V}_TVAL_EL0 have bits [63:32]
RES0 [1]. When reading the register, the value is truncated to the least
significant 32 bits [2], and on writes, TimerValue is treated as a signed
32-bit integer [1, 2].

When the guest behaves correctly and writes 32-bit values, treating TVAL
as an unsigned 64 bit register works as expected. However, things start
to break down when the guest writes larger values, because
(u64)0x1_ffff_ffff = 8589934591. but (s32)0x1_ffff_ffff = -1, and the
former will cause the timer interrupt to be asserted in the future, but
the latter will cause it to be asserted now.  Let's treat TVAL as a
signed 32-bit register on writes, to match the behaviour described in
the architecture, and the behaviour experimentally exhibited by the
virtual timer on a non-vhe host.

[1] Arm DDI 0487E.a, section D13.8.18
[2] Arm DDI 0487E.a, section D11.2.4

Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
[maz: replaced the read-side mask with lower_32_bits]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Fixes: 8fa7616248 ("KVM: arm/arm64: arch_timer: Fix CNTP_TVAL calculation")
Link: https://lore.kernel.org/r/20200127103652.2326-1-alexandru.elisei@arm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-14 16:53:04 -05:00
Eric Auger
35696255ed KVM: arm64: pmu: Fix chained SW_INCR counters
commit aa76829171 upstream.

At the moment a SW_INCR counter always overflows on 32-bit
boundary, independently on whether the n+1th counter is
programmed as CHAIN.

Check whether the SW_INCR counter is a 64b counter and if so,
implement the 64b logic.

Fixes: 80f393a23b ("KVM: arm/arm64: Support chained PMU counters")
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200124142535.29386-4-eric.auger@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-14 16:53:04 -05:00
Eric Auger
38342cf9a8 KVM: arm64: pmu: Don't increment SW_INCR if PMCR.E is unset
commit 3837407c1a upstream.

The specification says PMSWINC increments PMEVCNTR<n>_EL1 by 1
if PMEVCNTR<n>_EL0 is enabled and configured to count SW_INCR.

For PMEVCNTR<n>_EL0 to be enabled, we need both PMCNTENSET to
be set for the corresponding event counter but we also need
the PMCR.E bit to be set.

Fixes: 7a0adc7064 ("arm64: KVM: Add access handler for PMSWINC register")
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Andrew Murray <andrew.murray@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200124142535.29386-2-eric.auger@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-14 16:53:04 -05:00
James Morse
b5fedd5c1e KVM: arm: Make inject_abt32() inject an external abort instead
commit 21aecdbd7f upstream.

KVM's inject_abt64() injects an external-abort into an aarch64 guest.
The KVM_CAP_ARM_INJECT_EXT_DABT is intended to do exactly this, but
for an aarch32 guest inject_abt32() injects an implementation-defined
exception, 'Lockdown fault'.

Change this to external abort. For non-LPAE we now get the documented:
| Unhandled fault: external abort on non-linefetch (0x008) at 0x9c800f00
and for LPAE:
| Unhandled fault: synchronous external abort (0x210) at 0x9c800f00

Fixes: 74a64a9816 ("KVM: arm/arm64: Unify 32bit fault injection")
Reported-by: Beata Michalska <beata.michalska@linaro.org>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200121123356.203000-3-james.morse@arm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-14 16:53:04 -05:00
James Morse
d1af171974 KVM: arm: Fix DFSR setting for non-LPAE aarch32 guests
commit 018f22f95e upstream.

Beata reports that KVM_SET_VCPU_EVENTS doesn't inject the expected
exception to a non-LPAE aarch32 guest.

The host intends to inject DFSR.FS=0x14 "IMPLEMENTATION DEFINED fault
(Lockdown fault)", but the guest receives DFSR.FS=0x04 "Fault on
instruction cache maintenance". This fault is hooked by
do_translation_fault() since ARMv6, which goes on to silently 'handle'
the exception, and restart the faulting instruction.

It turns out, when TTBCR.EAE is clear DFSR is split, and FS[4] has
to shuffle up to DFSR[10].

As KVM only does this in one place, fix up the static values. We
now get the expected:
| Unhandled fault: lock abort (0x404) at 0x9c800f00

Fixes: 74a64a9816 ("KVM: arm/arm64: Unify 32bit fault injection")
Reported-by: Beata Michalska <beata.michalska@linaro.org>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200121123356.203000-2-james.morse@arm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-14 16:53:04 -05:00
Gavin Shan
849d3987a1 KVM: arm/arm64: Fix young bit from mmu notifier
commit cf2d23e0ba upstream.

kvm_test_age_hva() is called upon mmu_notifier_test_young(), but wrong
address range has been passed to handle_hva_to_gpa(). With the wrong
address range, no young bits will be checked in handle_hva_to_gpa().
It means zero is always returned from mmu_notifier_test_young().

This fixes the issue by passing correct address range to the underly
function handle_hva_to_gpa(), so that the hardware young (access) bit
will be visited.

Fixes: 35307b9a5f ("arm/arm64: KVM: Implement Stage-2 page aging")
Signed-off-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200121055659.19560-1-gshan@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-14 16:53:03 -05:00
Eric Auger
0ebe31af3d KVM: arm/arm64: vgic-its: Fix restoration of unmapped collections
commit 8c58be3449 upstream.

Saving/restoring an unmapped collection is a valid scenario. For
example this happens if a MAPTI command was sent, featuring an
unmapped collection. At the moment the CTE fails to be restored.
Only compare against the number of online vcpus if the rdist
base is set.

Fixes: ea1ad53e1e ("KVM: arm64: vgic-its: Collection table save/restore")
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Link: https://lore.kernel.org/r/20191213094237.19627-1-eric.auger@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-14 16:53:03 -05:00
Christoffer Dall
3e27597687 KVM: arm64: Only sign-extend MMIO up to register width
commit b6ae256afd upstream.

On AArch64 you can do a sign-extended load to either a 32-bit or 64-bit
register, and we should only sign extend the register up to the width of
the register as specified in the operation (by using the 32-bit Wn or
64-bit Xn register specifier).

As it turns out, the architecture provides this decoding information in
the SF ("Sixty-Four" -- how cute...) bit.

Let's take advantage of this with the usual 32-bit/64-bit header file
dance and do the right thing on AArch64 hosts.

Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20191212195055.5541-1-christoffer.dall@arm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:36:47 -08:00
Mark Rutland
70d8fc9129 KVM: arm/arm64: Correct AArch32 SPSR on exception entry
commit 1cfbb484de upstream.

Confusingly, there are three SPSR layouts that a kernel may need to deal
with:

(1) An AArch64 SPSR_ELx view of an AArch64 pstate
(2) An AArch64 SPSR_ELx view of an AArch32 pstate
(3) An AArch32 SPSR_* view of an AArch32 pstate

When the KVM AArch32 support code deals with SPSR_{EL2,HYP}, it's either
dealing with #2 or #3 consistently. On arm64 the PSR_AA32_* definitions
match the AArch64 SPSR_ELx view, and on arm the PSR_AA32_* definitions
match the AArch32 SPSR_* view.

However, when we inject an exception into an AArch32 guest, we have to
synthesize the AArch32 SPSR_* that the guest will see. Thus, an AArch64
host needs to synthesize layout #3 from layout #2.

This patch adds a new host_spsr_to_spsr32() helper for this, and makes
use of it in the KVM AArch32 support code. For arm64 we need to shuffle
the DIT bit around, and remove the SS bit, while for arm we can use the
value as-is.

I've open-coded the bit manipulation for now to avoid having to rework
the existing PSR_* definitions into PSR64_AA32_* and PSR32_AA32_*
definitions. I hope to perform a more thorough refactoring in future so
that we can handle pstate view manipulation more consistently across the
kernel tree.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200108134324.46500-4-mark.rutland@arm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:36:46 -08:00
Mark Rutland
3117265a94 KVM: arm/arm64: Correct CPSR on exception entry
commit 3c2483f154 upstream.

When KVM injects an exception into a guest, it generates the CPSR value
from scratch, configuring CPSR.{M,A,I,T,E}, and setting all other
bits to zero.

This isn't correct, as the architecture specifies that some CPSR bits
are (conditionally) cleared or set upon an exception, and others are
unchanged from the original context.

This patch adds logic to match the architectural behaviour. To make this
simple to follow/audit/extend, documentation references are provided,
and bits are configured in order of their layout in SPSR_EL2. This
layout can be seen in the diagram on ARM DDI 0487E.a page C5-426.

Note that this code is used by both arm and arm64, and is intended to
fuction with the SPSR_EL2 and SPSR_HYP layouts.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200108134324.46500-3-mark.rutland@arm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:36:46 -08:00
Paolo Bonzini
f5d5f5fae4 KVM/arm fixes for .5.5, take #1
- Fix uninitialised sysreg accessor
 - Fix handling of demand-paged device mappings
 - Stop spamming the console on IMPDEF sysregs
 - Relax mappings of writable memslots
 - Assorted cleanups
 -----BEGIN PGP SIGNATURE-----
 
 iQJDBAABCgAtFiEEn9UcU+C1Yxj9lZw9I9DQutE9ekMFAl3ydlsPHG1hekBrZXJu
 ZWwub3JnAAoJECPQ0LrRPXpDRLIQAIrwXMd5LnXS62AFmDtze1Q4uFsRf1RsUJBY
 P5ZReCm3VZWt3SncHI7Tuy2VpzvRq1foTOBDe5tTqu2hkbXC0EIvQL/tcbdDTteG
 YInVVs6YiGIQ6GMGIgJTWOVmTHGTft5sEKdYeV2S30N+4drfSUnbUrOqRLs87VJ5
 WvFbl97Jg3CVLEdZ2ZdmxpufqH24WxEm2aGjncBOhKjxj1xokxKUSmxoJ0Zj95o5
 4kkjKkyNG1Gnt07qL2jUV52g7hnSo9NhgNu3XaU6vEv3Xy4YPrbBZwL3gM3f2lKk
 F4AFUDKqaskjWWlNscEYZYhUtd7Sx2s4tqFVQXUbPkBrUorhRHid4r1BiwGYZNb0
 pKB40kVXz8q5ZJV4qKhSQ2qwnyoGBw9LKkiqYqT4Wk0JLqizWjQyfX3bO1XHB2o/
 jz1VojegSrmWg+798osXCyT6Tjvuwyp8cvnY1tM5t2rO0ppTH6EtwAqhpBARou1V
 VOpqIVHI9yx4zok+TIQAZtRSI7eFisJIjSuFrqQkJUKdp7G+W1PM51LTcroZNNyD
 LEUnEPZPbONsH0shl8qV8rt7U2sN4eHSlsDhdaHe0mW2gllFIUbaSljH+IWBnmWV
 phOKFDZnIvE6hySJzCLiCuvRH9OGdEDSFe96cWNjHTa5EEYS0v9BARUO9zpoNcq+
 1w4YLExU
 =jJwo
 -----END PGP SIGNATURE-----

Merge tag 'kvmarm-fixes-5.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-master

KVM/arm fixes for .5.5, take #1

- Fix uninitialised sysreg accessor
- Fix handling of demand-paged device mappings
- Stop spamming the console on IMPDEF sysregs
- Relax mappings of writable memslots
- Assorted cleanups
2019-12-18 17:47:38 +01:00
Marc Zyngier
6d674e28f6 KVM: arm/arm64: Properly handle faulting of device mappings
A device mapping is normally always mapped at Stage-2, since there
is very little gain in having it faulted in.

Nonetheless, it is possible to end-up in a situation where the device
mapping has been removed from Stage-2 (userspace munmaped the VFIO
region, and the MMU notifier did its job), but present in a userspace
mapping (userpace has mapped it back at the same address). In such
a situation, the device mapping will be demand-paged as the guest
performs memory accesses.

This requires to be careful when dealing with mapping size, cache
management, and to handle potential execution of a device mapping.

Reported-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Alexandru Elisei <alexandru.elisei@arm.com>
Reviewed-by: James Morse <james.morse@arm.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20191211165651.7889-2-maz@kernel.org
2019-12-12 16:22:40 +00:00
Jia He
97418e968b KVM: arm/arm64: Remove excessive permission check in kvm_arch_prepare_memory_region
In kvm_arch_prepare_memory_region, arm kvm regards the memory region as
writable if the flag has no KVM_MEM_READONLY, and the vm is readonly if
!VM_WRITE.

But there is common usage for setting kvm memory region as follows:
e.g. qemu side (see the PROT_NONE flag)
1. mmap(NULL, size, PROT_NONE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
   memory_region_init_ram_ptr()
2. re mmap the above area with read/write authority.

Such example is used in virtio-fs qemu codes which hasn't been upstreamed
[1]. But seems we can't forbid this example.

Without this patch, it will cause an EPERM during kvm_set_memory_region()
and cause qemu boot crash.

As told by Ard, "the underlying assumption is incorrect, i.e., that the
value of vm_flags at this point in time defines how the VMA is used
during its lifetime. There may be other cases where a VMA is created
with VM_READ vm_flags that are changed to VM_READ|VM_WRITE later, and
we are currently rejecting this use case as well."

[1] https://gitlab.com/virtio-fs/qemu/blob/5a356e/hw/virtio/vhost-user-fs.c#L488

Suggested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Jia He <justin.he@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Link: https://lore.kernel.org/r/20191206020802.196108-1-justin.he@arm.com
2019-12-06 19:37:48 +00:00
Miaohe Lin
72a610f32e KVM: arm/arm64: vgic: Use wrapper function to lock/unlock all vcpus in kvm_vgic_create()
Use wrapper function lock_all_vcpus()/unlock_all_vcpus()
in kvm_vgic_create() to remove duplicated code dealing
with locking and unlocking all vcpus in a vm.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Link: https://lore.kernel.org/r/1575081918-11401-1-git-send-email-linmiaohe@huawei.com
2019-12-06 11:41:38 +00:00
Miaohe Lin
0bda9498dd KVM: arm/arm64: vgic: Fix potential double free dist->spis in __kvm_vgic_destroy()
In kvm_vgic_dist_init() called from kvm_vgic_map_resources(), if
dist->vgic_model is invalid, dist->spis will be freed without set
dist->spis = NULL. And in vgicv2 resources clean up path,
__kvm_vgic_destroy() will be called to free allocated resources.
And dist->spis will be freed again in clean up chain because we
forget to set dist->spis = NULL in kvm_vgic_dist_init() failed
path. So double free would happen.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/1574923128-19956-1-git-send-email-linmiaohe@huawei.com
2019-12-06 11:41:29 +00:00
Miaohe Lin
7e0befd521 KVM: arm/arm64: Get rid of unused arg in cpu_init_hyp_mode()
As arg dummy is not really needed, there's no need to pass
NULL when calling cpu_init_hyp_mode(). So clean it up.

Fixes: 67f6919766 ("arm64: kvm: allows kvm cpu hotplug")
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/1574320559-5662-1-git-send-email-linmiaohe@huawei.com
2019-12-06 11:41:18 +00:00
Marc Zyngier
cd7056ae34 Merge remote-tracking branch 'kvmarm/misc-5.5' into kvmarm/next 2019-11-08 11:27:29 +00:00
Marc Zyngier
ef2e78ddad KVM: arm64: Opportunistically turn off WFI trapping when using direct LPI injection
Just like we do for WFE trapping, it can be useful to turn off
WFI trapping when the physical CPU is not oversubscribed (that
is, the vcpu is the only runnable process on this CPU) *and*
that we're using direct injection of interrupts.

The conditions are reevaluated on each vcpu_load(), ensuring that
we don't switch to this mode on a busy system.

On a GICv4 system, this has the effect of reducing the generation
of doorbell interrupts to zero when the right conditions are
met, which is a huge improvement over the current situation
(where the doorbells are screaming if the CPU ever hits a
blocking WFI).

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Link: https://lore.kernel.org/r/20191107160412.30301-3-maz@kernel.org
2019-11-08 11:14:36 +00:00
Marc Zyngier
5bd90b0989 KVM: vgic-v4: Track the number of VLPIs per vcpu
In order to find out whether a vcpu is likely to be the target of
VLPIs (and to further optimize the way we deal with those), let's
track the number of VLPIs a vcpu can receive.

This gets implemented with an atomic variable that gets incremented
or decremented on map, unmap and move of a VLPI.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Link: https://lore.kernel.org/r/20191107160412.30301-2-maz@kernel.org
2019-11-08 11:13:24 +00:00
Thomas Gleixner
9090825fa9 KVM: arm/arm64: Let the timer expire in hardirq context on RT
The timers are canceled from an preempt-notifier which is invoked with
disabled preemption which is not allowed on PREEMPT_RT.
The timer callback is short so in could be invoked in hard-IRQ context
on -RT.

Let the timer expire on hard-IRQ context even on -RT.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Julien Grall <julien.grall@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20191107095424.16647-1-bigeasy@linutronix.de
2019-11-07 16:13:33 +00:00
Zenghui Yu
ca185b2609 KVM: arm/arm64: vgic: Don't rely on the wrong pending table
It's possible that two LPIs locate in the same "byte_offset" but target
two different vcpus, where their pending status are indicated by two
different pending tables.  In such a scenario, using last_byte_offset
optimization will lead KVM relying on the wrong pending table entry.
Let us use last_ptr instead, which can be treated as a byte index into
a pending table and also, can be vcpu specific.

Fixes: 280771252c ("KVM: arm64: vgic-v3: KVM_DEV_ARM_VGIC_SAVE_PENDING_TABLES")
Cc: stable@vger.kernel.org
Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20191029071919.177-4-yuzenghui@huawei.com
2019-10-29 13:47:39 +00:00
Zenghui Yu
bad36e4e8c KVM: arm/arm64: vgic: Fix some comments typo
Fix various comments, including wrong function names, grammar mistakes
and specification references.

Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20191029071919.177-3-yuzenghui@huawei.com
2019-10-29 13:47:32 +00:00
Marc Zyngier
8e01d9a396 KVM: arm64: vgic-v4: Move the GICv4 residency flow to be driven by vcpu_load/put
When the VHE code was reworked, a lot of the vgic stuff was moved around,
but the GICv4 residency code did stay untouched, meaning that we come
in and out of residency on each flush/sync, which is obviously suboptimal.

To address this, let's move things around a bit:

- Residency entry (flush) moves to vcpu_load
- Residency exit (sync) moves to vcpu_put
- On blocking (entry to WFI), we "put"
- On unblocking (exit from WFI), we "load"

Because these can nest (load/block/put/load/unblock/put, for example),
we now have per-VPE tracking of the residency state.

Additionally, vgic_v4_put gains a "need doorbell" parameter, which only
gets set to true when blocking because of a WFI. This allows a finer
control of the doorbell, which now also gets disabled as soon as
it gets signaled.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20191027144234.8395-2-maz@kernel.org
2019-10-28 16:20:58 +00:00
Marc Zyngier
a4b28f5c67 Merge remote-tracking branch 'kvmarm/kvm-arm64/stolen-time' into kvmarm-master/next 2019-10-24 15:04:09 +01:00
Steven Price
58772e9a3d KVM: arm64: Provide VCPU attributes for stolen time
Allow user space to inform the KVM host where in the physical memory
map the paravirtualized time structures should be located.

User space can set an attribute on the VCPU providing the IPA base
address of the stolen time structure for that VCPU. This must be
repeated for every VCPU in the VM.

The address is given in terms of the physical address visible to
the guest and must be 64 byte aligned. The guest will discover the
address via a hypercall.

Signed-off-by: Steven Price <steven.price@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-10-21 19:20:29 +01:00
Steven Price
8564d6372a KVM: arm64: Support stolen time reporting via shared structure
Implement the service call for configuring a shared structure between a
VCPU and the hypervisor in which the hypervisor can write the time
stolen from the VCPU's execution time by other tasks on the host.

User space allocates memory which is placed at an IPA also chosen by user
space. The hypervisor then updates the shared structure using
kvm_put_guest() to ensure single copy atomicity of the 64-bit value
reporting the stolen time in nanoseconds.

Whenever stolen time is enabled by the guest, the stolen time counter is
reset.

The stolen time itself is retrieved from the sched_info structure
maintained by the Linux scheduler code. We enable SCHEDSTATS when
selecting KVM Kconfig to ensure this value is meaningful.

Signed-off-by: Steven Price <steven.price@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-10-21 19:20:28 +01:00
Steven Price
b48c1a45a1 KVM: arm64: Implement PV_TIME_FEATURES call
This provides a mechanism for querying which paravirtualized time
features are available in this hypervisor.

Also add the header file which defines the ABI for the paravirtualized
time features we're about to add.

Signed-off-by: Steven Price <steven.price@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-10-21 19:20:27 +01:00
Christoffer Dall
55009c6ed2 KVM: arm/arm64: Factor out hypercall handling from PSCI code
We currently intertwine the KVM PSCI implementation with the general
dispatch of hypercall handling, which makes perfect sense because PSCI
is the only category of hypercalls we support.

However, as we are about to support additional hypercalls, factor out
this functionality into a separate hypercall handler file.

Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
[steven.price@arm.com: rebased]
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-10-21 19:20:26 +01:00
Christoffer Dall
da345174ce KVM: arm/arm64: Allow user injection of external data aborts
In some scenarios, such as buggy guest or incorrect configuration of the
VMM and firmware description data, userspace will detect a memory access
to a portion of the IPA, which is not mapped to any MMIO region.

For this purpose, the appropriate action is to inject an external abort
to the guest.  The kernel already has functionality to inject an
external abort, but we need to wire up a signal from user space that
lets user space tell the kernel to do this.

It turns out, we already have the set event functionality which we can
perfectly reuse for this.

Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-10-21 18:59:51 +01:00
Christoffer Dall
c726200dd1 KVM: arm/arm64: Allow reporting non-ISV data aborts to userspace
For a long time, if a guest accessed memory outside of a memslot using
any of the load/store instructions in the architecture which doesn't
supply decoding information in the ESR_EL2 (the ISV bit is not set), the
kernel would print the following message and terminate the VM as a
result of returning -ENOSYS to userspace:

  load/store instruction decoding not implemented

The reason behind this message is that KVM assumes that all accesses
outside a memslot is an MMIO access which should be handled by
userspace, and we originally expected to eventually implement some sort
of decoding of load/store instructions where the ISV bit was not set.

However, it turns out that many of the instructions which don't provide
decoding information on abort are not safe to use for MMIO accesses, and
the remaining few that would potentially make sense to use on MMIO
accesses, such as those with register writeback, are not used in
practice.  It also turns out that fetching an instruction from guest
memory can be a pretty horrible affair, involving stopping all CPUs on
SMP systems, handling multiple corner cases of address translation in
software, and more.  It doesn't appear likely that we'll ever implement
this in the kernel.

What is much more common is that a user has misconfigured his/her guest
and is actually not accessing an MMIO region, but just hitting some
random hole in the IPA space.  In this scenario, the error message above
is almost misleading and has led to a great deal of confusion over the
years.

It is, nevertheless, ABI to userspace, and we therefore need to
introduce a new capability that userspace explicitly enables to change
behavior.

This patch introduces KVM_CAP_ARM_NISV_TO_USER (NISV meaning Non-ISV)
which does exactly that, and introduces a new exit reason to report the
event to userspace.  User space can then emulate an exception to the
guest, restart the guest, suspend the guest, or take any other
appropriate action as per the policy of the running system.

Reported-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Reviewed-by: Alexander Graf <graf@amazon.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-10-21 18:59:44 +01:00
Marc Zyngier
8c3252c065 KVM: arm64: pmu: Reset sample period on overflow handling
The PMU emulation code uses the perf event sample period to trigger
the overflow detection. This works fine  for the *first* overflow
handling, but results in a huge number of interrupts on the host,
unrelated to the number of interrupts handled in the guest (a x20
factor is pretty common for the cycle counter). On a slow system
(such as a SW model), this can result in the guest only making
forward progress at a glacial pace.

It turns out that the clue is in the name. The sample period is
exactly that: a period. And once the an overflow has occured,
the following period should be the full width of the associated
counter, instead of whatever the guest had initially programed.

Reset the sample period to the architected value in the overflow
handler, which now results in a number of host interrupts that is
much closer to the number of interrupts in the guest.

Fixes: b02386eb7d ("arm64: KVM: Add PMU overflow interrupt routing")
Reviewed-by: Andrew Murray <andrew.murray@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-10-20 10:47:07 +01:00
Marc Zyngier
725ce66979 KVM: arm64: pmu: Set the CHAINED attribute before creating the in-kernel event
The current convention for KVM to request a chained event from the
host PMU is to set bit[0] in attr.config1 (PERF_ATTR_CFG1_KVM_PMU_CHAINED).

But as it turns out, this bit gets set *after* we create the kernel
event that backs our virtual counter, meaning that we never get
a 64bit counter.

Moving the setting to an earlier point solves the problem.

Fixes: 80f393a23b ("KVM: arm/arm64: Support chained PMU counters")
Reviewed-by: Andrew Murray <andrew.murray@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-10-20 10:47:07 +01:00
Marc Zyngier
f4e23cf947 KVM: arm64: pmu: Fix cycle counter truncation
When a counter is disabled, its value is sampled before the event
is being disabled, and the value written back in the shadow register.

In that process, the value gets truncated to 32bit, which is adequate
for any counter but the cycle counter (defined as a 64bit counter).

This obviously results in a corrupted counter, and things like
"perf record -e cycles" not working at all when run in a guest...
A similar, but less critical bug exists in kvm_pmu_get_counter_value.

Make the truncation conditional on the counter not being the cycle
counter, which results in a minor code reorganisation.

Fixes: 80f393a23b ("KVM: arm/arm64: Support chained PMU counters")
Reviewed-by: Andrew Murray <andrew.murray@arm.com>
Reported-by: Julien Thierry <julien.thierry.kdev@gmail.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-10-20 10:47:07 +01:00
Paolo Bonzini
d53a4c8e77 KVM/arm fixes for 5.4, take #1
- Remove the now obsolete hyp_alternate_select construct
 - Fix the TRACE_INCLUDE_PATH macro in the vgic code
 -----BEGIN PGP SIGNATURE-----
 
 iQJDBAABCgAtFiEEn9UcU+C1Yxj9lZw9I9DQutE9ekMFAl2TFyoPHG1hekBrZXJu
 ZWwub3JnAAoJECPQ0LrRPXpDROwP/inRUonz+KEG2B0Bx/NWtzdnDghxdcoNC9H6
 lVDHJ2dtC5Kmf0iHEualUvxXHYx7QJ3Maov3UAtkeYl3s4wC6TAl++QkqAG9PYsc
 lPQH4GBiQNewQyaebc/NKHDz3I3TClJDq57haHSFFiCwsUpJRgYL8WjktZD/Dide
 CUSQGxdnaALzHvMv5a8yQWadPL/RrXCZqOSKbUjjc20meZxrO66HwUd1G6uZZVDn
 VClMQwFkQzVjR7yX21/7gmTcwG99RqVaAsvOpCu9+MVlqSpDROspmSPMuG5X/usO
 zDgC07UFNPYHQKrGu8DHqlvO9DrK3vR8VEuKu+asVZP7D/ntvKhAM2c5ai188Z12
 w8rOnhJKnDtMGHXn4owcC9tgSfrPR+ZukaltzKRVVFm1Y1Io+qTkAuf3geFqZ1hj
 L9LWZ0KlMsFvfIKWPcAEp5rA9EeZoP5IeVCelBWj9ERDrcCMhma8RxpAlBPz1YPy
 J345jthE4xFZYQxV+amTKJ3CzbZPuU2iIKgDBYiG2PNCuKwCT46RQitOXWWTwSIb
 FZ6pcsmhofj69dSAlrRFjEpiLNkJuNX1ArsAA91vXemTXA2YfVLMZo1HkrmFNfbR
 j4HP1BhNVdCgk6HF2HzwdRt8eutvk889GG3q+uCoYCaSu3M8MUEgx64LurOPProO
 11jhNb3J
 =9luB
 -----END PGP SIGNATURE-----

Merge tag 'kvmarm-fixes-5.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm fixes for 5.4, take #1

- Remove the now obsolete hyp_alternate_select construct
- Fix the TRACE_INCLUDE_PATH macro in the vgic code
2019-10-03 12:08:50 +02:00
Linus Torvalds
fe38bd6862 * s390: ioctl hardening, selftests
* ARM: ITS translation cache; support for 512 vCPUs, various cleanups
 and bugfixes
 
 * PPC: various minor fixes and preparation
 
 * x86: bugfixes all over the place (posted interrupts, SVM, emulation
 corner cases, blocked INIT), some IPI optimizations
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.22 (GNU/Linux)
 
 iQEcBAABAgAGBQJdf7fdAAoJEL/70l94x66DJzkIAKDcuWXJB4Qtoto6yUvPiHZm
 LYkY/Dn1zulb/DhzrBoXFey/jZXwl9kxMYkVTefnrAl0fRwFGX+G1UYnQrtAL6Gr
 ifdTYdy3kZhXCnnp99QAantWDswJHo1THwbmHrlmkxS4MdisEaTHwgjaHrDRZ4/d
 FAEwW2isSonP3YJfTtsKFFjL9k2D4iMnwZ/R2B7UOaWvgnerZ1GLmOkilvnzGGEV
 IQ89IIkWlkKd4SKgq8RkDKlfW5JrLrSdTK2Uf0DvAxV+J0EFkEaR+WlLsqumra0z
 Eg3KwNScfQj0DyT0TzurcOxObcQPoMNSFYXLRbUu1+i0CGgm90XpF1IosiuihgU=
 =w6I3
 -----END PGP SIGNATURE-----

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

Pull KVM updates from Paolo Bonzini:
 "s390:
   - ioctl hardening
   - selftests

  ARM:
   - ITS translation cache
   - support for 512 vCPUs
   - various cleanups and bugfixes

  PPC:
   - various minor fixes and preparation

  x86:
   - bugfixes all over the place (posted interrupts, SVM, emulation
     corner cases, blocked INIT)
   - some IPI optimizations"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (75 commits)
  KVM: X86: Use IPI shorthands in kvm guest when support
  KVM: x86: Fix INIT signal handling in various CPU states
  KVM: VMX: Introduce exit reason for receiving INIT signal on guest-mode
  KVM: VMX: Stop the preemption timer during vCPU reset
  KVM: LAPIC: Micro optimize IPI latency
  kvm: Nested KVM MMUs need PAE root too
  KVM: x86: set ctxt->have_exception in x86_decode_insn()
  KVM: x86: always stop emulation on page fault
  KVM: nVMX: trace nested VM-Enter failures detected by H/W
  KVM: nVMX: add tracepoint for failed nested VM-Enter
  x86: KVM: svm: Fix a check in nested_svm_vmrun()
  KVM: x86: Return to userspace with internal error on unexpected exit reason
  KVM: x86: Add kvm_emulate_{rd,wr}msr() to consolidate VXM/SVM code
  KVM: x86: Refactor up kvm_{g,s}et_msr() to simplify callers
  doc: kvm: Fix return description of KVM_SET_MSRS
  KVM: X86: Tune PLE Window tracepoint
  KVM: VMX: Change ple_window type to unsigned int
  KVM: X86: Remove tailing newline for tracepoints
  KVM: X86: Trace vcpu_id for vmexit
  KVM: x86: Manually calculate reserved bits when loading PDPTRS
  ...
2019-09-18 09:49:13 -07:00
Zenghui Yu
aac60f1a86 KVM: arm/arm64: vgic: Use the appropriate TRACE_INCLUDE_PATH
Commit 49dfe94fe5 ("KVM: arm/arm64: Fix TRACE_INCLUDE_PATH") fixes
TRACE_INCLUDE_PATH to the correct relative path to the define_trace.h
and explains why did the old one work.

The same fix should be applied to virt/kvm/arm/vgic/trace.h.

Reviewed-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-09-11 16:36:19 +01:00
Marc Zyngier
92f35b751c KVM: arm/arm64: vgic: Allow more than 256 vcpus for KVM_IRQ_LINE
While parts of the VGIC support a large number of vcpus (we
bravely allow up to 512), other parts are more limited.

One of these limits is visible in the KVM_IRQ_LINE ioctl, which
only allows 256 vcpus to be signalled when using the CPU or PPI
types. Unfortunately, we've cornered ourselves badly by allocating
all the bits in the irq field.

Since the irq_type subfield (8 bit wide) is currently only taking
the values 0, 1 and 2 (and we have been careful not to allow anything
else), let's reduce this field to only 4 bits, and allocate the
remaining 4 bits to a vcpu2_index, which acts as a multiplier:

  vcpu_id = 256 * vcpu2_index + vcpu_index

With that, and a new capability (KVM_CAP_ARM_IRQ_LINE_LAYOUT_2)
allowing this to be discovered, it becomes possible to inject
PPIs to up to 4096 vcpus. But please just don't.

Whilst we're there, add a clarification about the use of KVM_IRQ_LINE
on arm, which is not completely conditionned by KVM_CAP_IRQCHIP.

Reported-by: Zenghui Yu <yuzenghui@huawei.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-09-09 12:29:09 +01:00
Linus Torvalds
9cf6b756cd arm64 fixes for -rc7
- Fix GICv2 emulation bug (KVM)
 
 - Fix deadlock in virtual GIC interrupt injection code (KVM)
 
 - Fix kprobes blacklist init failure due to broken kallsyms lookup
 -----BEGIN PGP SIGNATURE-----
 
 iQEzBAABCgAdFiEEPxTL6PPUbjXGY88ct6xw3ITBYzQFAl1mW/0ACgkQt6xw3ITB
 YzQWEQgAnG+20c1uzPqIEME3o0bCXsci0I1w4yPYPH/NVrfmJdAjfway/cLZlMCh
 JYKBTc392kfYXgzAvMqvjNe+9O/qg9MnMxV7Afjfk9e0k+41Kcw/7U39/B6q4yOg
 zIz4YW6SdbbbUfY9VgR8SjsZ3HwJoP8YVNEv3W259funtFHkKDO35h1iG1f57GWL
 UELjEnag9dmCH35ykt7+SC4woBGjOQnic2XLSS7VZuU/26TfnUyo2HCdDcLcViCZ
 DHDQgaHAscb+tgJjeNtNEeRu+GPBG9LOhPw4EpBjGHeoJla7z74GOJPMEt4Ufoqd
 qG9TPfOFAFM30/PAdlWF3SjfzqK3PA==
 =WYzY
 -----END PGP SIGNATURE-----

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

Pull arm64 fixes from Will Deacon:
 "Hot on the heels of our last set of fixes are a few more for -rc7.

  Two of them are fixing issues with our virtual interrupt controller
  implementation in KVM/arm, while the other is a longstanding but
  straightforward kallsyms fix which was been acked by Masami and
  resolves an initialisation failure in kprobes observed on arm64.

   - Fix GICv2 emulation bug (KVM)

   - Fix deadlock in virtual GIC interrupt injection code (KVM)

   - Fix kprobes blacklist init failure due to broken kallsyms lookup"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  KVM: arm/arm64: vgic-v2: Handle SGI bits in GICD_I{S,C}PENDR0 as WI
  KVM: arm/arm64: vgic: Fix potential deadlock when ap_list is long
  kallsyms: Don't let kallsyms_lookup_size_offset() fail on retrieving the first symbol
2019-08-28 10:37:21 -07:00
Marc Zyngier
82e40f558d KVM: arm/arm64: vgic-v2: Handle SGI bits in GICD_I{S,C}PENDR0 as WI
A guest is not allowed to inject a SGI (or clear its pending state)
by writing to GICD_ISPENDR0 (resp. GICD_ICPENDR0), as these bits are
defined as WI (as per ARM IHI 0048B 4.3.7 and 4.3.8).

Make sure we correctly emulate the architecture.

Fixes: 96b298000d ("KVM: arm/arm64: vgic-new: Add PENDING registers handlers")
Cc: stable@vger.kernel.org # 4.7+
Reported-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-28 11:21:42 +01:00
Heyi Guo
d4a8061a7c KVM: arm/arm64: vgic: Fix potential deadlock when ap_list is long
If the ap_list is longer than 256 entries, merge_final() in list_sort()
will call the comparison callback with the same element twice, causing
a deadlock in vgic_irq_cmp().

Fix it by returning early when irqa == irqb.

Cc: stable@vger.kernel.org # 4.7+
Fixes: 8e44474579 ("KVM: arm/arm64: vgic-new: Add IRQ sorting")
Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Heyi Guo <guoheyi@huawei.com>
[maz: massaged commit log and patch, added Fixes and Cc-stable]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-27 16:19:56 +01:00
Eric Auger
3109741a8d KVM: arm/arm64: vgic: Use a single IO device per redistributor
At the moment we use 2 IO devices per GICv3 redistributor: one
one for the RD_base frame and one for the SGI_base frame.

Instead we can use a single IO device per redistributor (the 2
frames are contiguous). This saves slots on the KVM_MMIO_BUS
which is currently limited to NR_IOBUS_DEVS (1000).

This change allows to instantiate up to 512 redistributors and may
speed the guest boot with a large number of VCPUs.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-08-25 11:02:52 +01:00
Marc Zyngier
926c61568d KVM: arm/arm64: vgic: Remove spurious semicolons
Detected by Coccinelle (and Will Deacon) using
scripts/coccinelle/misc/semicolon.cocci.

Reported-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-08-25 11:02:13 +01:00
Will Deacon
087eeea9ad KVM/arm fixes for 5.3, take #3
- Don't overskip instructions on MMIO emulation
 - Fix UBSAN splat when initializing PPI priorities
 -----BEGIN PGP SIGNATURE-----
 
 iQJDBAABCgAtFiEEn9UcU+C1Yxj9lZw9I9DQutE9ekMFAl1gE4sPHG1hekBrZXJu
 ZWwub3JnAAoJECPQ0LrRPXpDvT0QALDyWgNXugpyOTbuH01zgTT5W2PxWPnLT6bl
 yCN84C2falMjLgsvBGJo+HuD8nOTwCsam+6mVnbVOmXjDpFtsp1z/unJ9Cv9T4e+
 1/TSDgp1Y1wJsdfVMqLOj2LOJterVC65e+eRp4ShEaCaGl0QsJLQIZNndoycen8K
 XcwLokABKoypctGz/1XJD9fX0GeJdgJQ2dASVuccaWxvo0lrD5qoRlZUIdWKjTmn
 OneayyIB8Dqn2Ju/bQ9bbTzg5VLfw2L9lnrVAlaFnWZETWHAtG6uCK6Zj/eDNZj8
 TFBwXtKLbdJPQO+JR7l40QjvK/qkHdVaOp4M1kB+4niYogK23WlWvh7kZ/sZbAUb
 A1PRQ39L6f0LJrJJtWeS/bJyUmBnX4PJkwZMNV4EN4fXDi2+79/DxUKXih+im/WN
 W26WMAqFwxKiMSEENLfl4ladmrgo9SUBeI8QAnEgvUChCcy9HGpKgQp/KjImM9b3
 ab87VS8BUYfyThF7PPshfBteWg3rHPQY2kjRn7B8yRhCcoWBErGtXkEdIhxvtfjk
 hUgvT8CPk4uoh4DynqRxvDR16xMPwpUTtedVoZzIkGgG6ZLHAdX0303OLaRZ/KDl
 j6vKdm8rU5I4samalckcHuoP+t2Hmmdbd0JNo+BaiorbtBXXXJQWd++85tCMniTg
 kWGoHUn5
 =FGm5
 -----END PGP SIGNATURE-----

Merge tag 'kvmarm-fixes-for-5.3-3' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm/fixes

Pull KVM/arm fixes from Marc Zyngier as per Paulo's request at:

  https://lkml.kernel.org/r/21ae69a2-2546-29d0-bff6-2ea825e3d968@redhat.com

  "One (hopefully last) set of fixes for KVM/arm for 5.3: an embarassing
   MMIO emulation regression, and a UBSAN splat. Oh well...

   - Don't overskip instructions on MMIO emulation

   - Fix UBSAN splat when initializing PPI priorities"

* tag 'kvmarm-fixes-for-5.3-3' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm:
  KVM: arm/arm64: VGIC: Properly initialise private IRQ affinity
  KVM: arm/arm64: Only skip MMIO insn once
2019-08-24 12:46:30 +01:00
Andre Przywara
2e16f3e926 KVM: arm/arm64: VGIC: Properly initialise private IRQ affinity
At the moment we initialise the target *mask* of a virtual IRQ to the
VCPU it belongs to, even though this mask is only defined for GICv2 and
quickly runs out of bits for many GICv3 guests.
This behaviour triggers an UBSAN complaint for more than 32 VCPUs:
------
[ 5659.462377] UBSAN: Undefined behaviour in virt/kvm/arm/vgic/vgic-init.c:223:21
[ 5659.471689] shift exponent 32 is too large for 32-bit type 'unsigned int'
------
Also for GICv3 guests the reporting of TARGET in the "vgic-state" debugfs
dump is wrong, due to this very same problem.

Because there is no requirement to create the VGIC device before the
VCPUs (and QEMU actually does it the other way round), we can't safely
initialise mpidr or targets in kvm_vgic_vcpu_init(). But since we touch
every private IRQ for each VCPU anyway later (in vgic_init()), we can
just move the initialisation of those fields into there, where we
definitely know the VGIC type.

On the way make sure we really have either a VGICv2 or a VGICv3 device,
since the existing code is just checking for "VGICv3 or not", silently
ignoring the uninitialised case.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reported-by: Dave Martin <dave.martin@arm.com>
Tested-by: Julien Grall <julien.grall@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-08-23 17:23:01 +01:00
Andrew Jones
2113c5f62b KVM: arm/arm64: Only skip MMIO insn once
If after an MMIO exit to userspace a VCPU is immediately run with an
immediate_exit request, such as when a signal is delivered or an MMIO
emulation completion is needed, then the VCPU completes the MMIO
emulation and immediately returns to userspace. As the exit_reason
does not get changed from KVM_EXIT_MMIO in these cases we have to
be careful not to complete the MMIO emulation again, when the VCPU is
eventually run again, because the emulation does an instruction skip
(and doing too many skips would be a waste of guest code :-) We need
to use additional VCPU state to track if the emulation is complete.
As luck would have it, we already have 'mmio_needed', which even
appears to be used in this way by other architectures already.

Fixes: 0d640732db ("arm64: KVM: Skip MMIO insn after emulation")
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-08-22 13:19:56 +01:00
Alexandru Elisei
0ed5f5d639 KVM: arm/arm64: vgic: Make function comments match function declarations
Since commit 503a62862e ("KVM: arm/arm64: vgic: Rely on the GIC driver to
parse the firmware tables"), the vgic_v{2,3}_probe functions stopped using
a DT node. Commit 9097773245 ("KVM: arm/arm64: vgic-new: vgic_init:
implement kvm_vgic_hyp_init") changed the functions again, and now they
require exactly one argument, a struct gic_kvm_info populated by the GIC
driver. Unfortunately the comments regressed and state that a DT node is
used instead. Change the function comments to reflect the current
prototypes.

Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-08-18 18:44:04 +01:00
Marc Zyngier
41108170d9 KVM: arm/arm64: vgic-irqfd: Implement kvm_arch_set_irq_inatomic
Now that we have a cache of MSI->LPI translations, it is pretty
easy to implement kvm_arch_set_irq_inatomic (this cache can be
parsed without sleeping).

Hopefully, this will improve some LPI-heavy workloads.

Tested-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-08-18 18:38:54 +01:00
Marc Zyngier
86a7dae884 KVM: arm/arm64: vgic-its: Check the LPI translation cache on MSI injection
When performing an MSI injection, let's first check if the translation
is already in the cache. If so, let's inject it quickly without
going through the whole translation process.

Tested-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-08-18 18:38:53 +01:00
Marc Zyngier
89489ee9ce KVM: arm/arm64: vgic-its: Cache successful MSI->LPI translation
On a successful translation, preserve the parameters in the LPI
translation cache. Each translation is reusing the last slot
in the list, naturally evicting the least recently used entry.

Tested-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-08-18 18:38:52 +01:00
Marc Zyngier
cbfda481d8 KVM: arm/arm64: vgic-its: Invalidate MSI-LPI translation cache on vgic teardown
In order to avoid leaking vgic_irq structures on teardown, we need to
drop all references to LPIs before deallocating the cache itself.

This is done by invalidating the cache on vgic teardown.

Tested-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-08-18 18:38:51 +01:00