External inputs to the vgic from time to time need to poke into the
state of a virtual interrupt, the prime example is the architected timer
code.
Since the IRQ's active state can be represented in two places; the LR or
the distributor, we first loop over the LRs but if not active in the LRs
we just return if *any* IRQ is active on the VCPU in question.
This is of course bogus, as we should check if the specific IRQ in
quesiton is active on the distributor instead.
Reported-by: Eric Auger <eric.auger@linaro.org>
Acked-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>
We were probing the physial distributor state for the active state of a
HW virtual IRQ, because we had seen evidence that the LR state was not
cleared when the guest deactivated a virtual interrupted.
However, this issue turned out to be a software bug in the GIC, which
was solved by: 84aab5e68c2a5e1e18d81ae8308c3ce25d501b29
(KVM: arm/arm64: arch_timer: Preserve physical dist. active
state on LR.active, 2015-11-24)
Therefore, get rid of the complexities and just look at the LR.
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
We were incorrectly removing the active state from the physical
distributor on the timer interrupt when the timer output level was
deasserted. We shouldn't be doing this without considering the virtual
interrupt's active state, because the architecture requires that when an
LR has the HW bit set and the pending or active bits set, then the
physical interrupt must also have the corresponding bits set.
This addresses an issue where we have been observing an inconsistency
between the LR state and the physical distributor state where the LR
state was active and the physical distributor was not active, which
shouldn't happen.
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
handling.
PPC: Mostly bug fixes.
ARM: No big features, but many small fixes and prerequisites including:
- a number of fixes for the arch-timer
- introducing proper level-triggered semantics for the arch-timers
- a series of patches to synchronously halt a guest (prerequisite for
IRQ forwarding)
- some tracepoint improvements
- a tweak for the EL2 panic handlers
- some more VGIC cleanups getting rid of redundant state
x86: quite a few changes:
- support for VT-d posted interrupts (i.e. PCI devices can inject
interrupts directly into vCPUs). This introduces a new component (in
virt/lib/) that connects VFIO and KVM together. The same infrastructure
will be used for ARM interrupt forwarding as well.
- more Hyper-V features, though the main one Hyper-V synthetic interrupt
controller will have to wait for 4.5. These will let KVM expose Hyper-V
devices.
- nested virtualization now supports VPID (same as PCID but for vCPUs)
which makes it quite a bit faster
- for future hardware that supports NVDIMM, there is support for clflushopt,
clwb, pcommit
- support for "split irqchip", i.e. LAPIC in kernel + IOAPIC/PIC/PIT in
userspace, which reduces the attack surface of the hypervisor
- obligatory smattering of SMM fixes
- on the guest side, stable scheduler clock support was rewritten to not
require help from the hypervisor.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.22 (GNU/Linux)
iQEcBAABAgAGBQJWO2IQAAoJEL/70l94x66D/K0H/3AovAgYmJQToZlimsktMk6a
f2xhdIqfU5lIQQh5uNBCfL3o9o8H9Py1ym7aEw3fmztPHHJYc91oTatt2UEKhmEw
VtZHp/dFHt3hwaIdXmjRPEXiYctraKCyrhaUYdWmUYkoKi7lW5OL5h+S7frG2U6u
p/hFKnHRZfXHr6NSgIqvYkKqtnc+C0FWY696IZMzgCksOO8jB1xrxoSN3tANW3oJ
PDV+4og0fN/Fr1capJUFEc/fejREHneANvlKrLaa8ht0qJQutoczNADUiSFLcMPG
iHljXeDsv5eyjMtUuIL8+MPzcrIt/y4rY41ZPiKggxULrXc6H+JJL/e/zThZpXc=
=iv2z
-----END PGP SIGNATURE-----
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Paolo Bonzini:
"First batch of KVM changes for 4.4.
s390:
A bunch of fixes and optimizations for interrupt and time handling.
PPC:
Mostly bug fixes.
ARM:
No big features, but many small fixes and prerequisites including:
- a number of fixes for the arch-timer
- introducing proper level-triggered semantics for the arch-timers
- a series of patches to synchronously halt a guest (prerequisite
for IRQ forwarding)
- some tracepoint improvements
- a tweak for the EL2 panic handlers
- some more VGIC cleanups getting rid of redundant state
x86:
Quite a few changes:
- support for VT-d posted interrupts (i.e. PCI devices can inject
interrupts directly into vCPUs). This introduces a new
component (in virt/lib/) that connects VFIO and KVM together.
The same infrastructure will be used for ARM interrupt
forwarding as well.
- more Hyper-V features, though the main one Hyper-V synthetic
interrupt controller will have to wait for 4.5. These will let
KVM expose Hyper-V devices.
- nested virtualization now supports VPID (same as PCID but for
vCPUs) which makes it quite a bit faster
- for future hardware that supports NVDIMM, there is support for
clflushopt, clwb, pcommit
- support for "split irqchip", i.e. LAPIC in kernel +
IOAPIC/PIC/PIT in userspace, which reduces the attack surface of
the hypervisor
- obligatory smattering of SMM fixes
- on the guest side, stable scheduler clock support was rewritten
to not require help from the hypervisor"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (123 commits)
KVM: VMX: Fix commit which broke PML
KVM: x86: obey KVM_X86_QUIRK_CD_NW_CLEARED in kvm_set_cr0()
KVM: x86: allow RSM from 64-bit mode
KVM: VMX: fix SMEP and SMAP without EPT
KVM: x86: move kvm_set_irq_inatomic to legacy device assignment
KVM: device assignment: remove pointless #ifdefs
KVM: x86: merge kvm_arch_set_irq with kvm_set_msi_inatomic
KVM: x86: zero apic_arb_prio on reset
drivers/hv: share Hyper-V SynIC constants with userspace
KVM: x86: handle SMBASE as physical address in RSM
KVM: x86: add read_phys to x86_emulate_ops
KVM: x86: removing unused variable
KVM: don't pointlessly leave KVM_COMPAT=y in non-KVM configs
KVM: arm/arm64: Merge vgic_set_lr() and vgic_sync_lr_elrsr()
KVM: arm/arm64: Clean up vgic_retire_lr() and surroundings
KVM: arm/arm64: Optimize away redundant LR tracking
KVM: s390: use simple switch statement as multiplexer
KVM: s390: drop useless newline in debugging data
KVM: s390: SCA must not cross page boundaries
KVM: arm: Do not indent the arguments of DECLARE_BITMAP
...
Now we see that vgic_set_lr() and vgic_sync_lr_elrsr() are always used
together. Merge them into one function, saving from second vgic_ops
dereferencing every time.
Signed-off-by: Pavel Fedin <p.fedin@samsung.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
1. Remove unnecessary 'irq' argument, because irq number can be retrieved
from the LR.
2. Since cff9211eb1
("arm/arm64: KVM: Fix arch timer behavior for disabled interrupts ")
LR_STATE_PENDING is queued back by vgic_retire_lr() itself. Also, it
clears vlr.state itself. Therefore, we remove the same, now duplicated,
check with all accompanying bit manipulations from vgic_unqueue_irqs().
3. vgic_retire_lr() is always accompanied by vgic_irq_clear_queued(). Since
it already does more than just clearing the LR, move
vgic_irq_clear_queued() inside of it.
Signed-off-by: Pavel Fedin <p.fedin@samsung.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Currently we use vgic_irq_lr_map in order to track which LRs hold which
IRQs, and lr_used bitmap in order to track which LRs are used or free.
vgic_irq_lr_map is actually used only for piggy-back optimization, and
can be easily replaced by iteration over lr_used. This is good because in
future, when LPI support is introduced, number of IRQs will grow up to at
least 16384, while numbers from 1024 to 8192 are never going to be used.
This would be a huge memory waste.
In its turn, lr_used is also completely redundant since
ae705930fc ("arm/arm64: KVM: Keep elrsr/aisr
in sync with software model"), because together with lr_used we also update
elrsr. This allows to easily replace lr_used with elrsr, inverting all
conditions (because in elrsr '1' means 'free').
Signed-off-by: Pavel Fedin <p.fedin@samsung.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Pull irq updates from Thomas Gleixner:
"The irq departement delivers:
- Rework the irqdomain core infrastructure to accomodate ACPI based
systems. This is required to support ARM64 without creating
artificial device tree nodes.
- Sanitize the ACPI based ARM GIC initialization by making use of the
new firmware independent irqdomain core
- Further improvements to the generic MSI management
- Generalize the irq migration on CPU hotplug
- Improvements to the threaded interrupt infrastructure
- Allow the migration of "chained" low level interrupt handlers
- Allow optional force masking of interrupts in disable_irq[_nosysnc]
- Support for two new interrupt chips - Sigh!
- A larger set of errata fixes for ARM gicv3
- The usual pile of fixes, updates, improvements and cleanups all
over the place"
* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (71 commits)
Document that IRQ_NONE should be returned when IRQ not actually handled
PCI/MSI: Allow the MSI domain to be device-specific
PCI: Add per-device MSI domain hook
of/irq: Use the msi-map property to provide device-specific MSI domain
of/irq: Split of_msi_map_rid to reuse msi-map lookup
irqchip/gic-v3-its: Parse new version of msi-parent property
PCI/MSI: Use of_msi_get_domain instead of open-coded "msi-parent" parsing
of/irq: Use of_msi_get_domain instead of open-coded "msi-parent" parsing
of/irq: Add support code for multi-parent version of "msi-parent"
irqchip/gic-v3-its: Add handling of PCI requester id.
PCI/MSI: Add helper function pci_msi_domain_get_msi_rid().
of/irq: Add new function of_msi_map_rid()
Docs: dt: Add PCI MSI map bindings
irqchip/gic-v2m: Add support for multiple MSI frames
irqchip/gic-v3: Fix translation of LPIs after conversion to irq_fwspec
irqchip/mxs: Add Alphascale ASM9260 support
irqchip/mxs: Prepare driver for hardware with different offsets
irqchip/mxs: Panic if ioremap or domain creation fails
irqdomain: Documentation updates
irqdomain/msi: Use fwnode instead of of_node
...
The VGIC and timer code for KVM arm/arm64 doesn't have any tracepoints
or tracepoint infrastructure defined. Rewriting some of the timer code
handling showed me how much we need this, so let's add these simple
trace points once and for all and we can easily expand with additional
trace points in these files as we go along.
Cc: Wei Huang <wei@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
We mark edge-triggered interrupts with the HW bit set as queued to
prevent the VGIC code from injecting LRs with both the Active and
Pending bits set at the same time while also setting the HW bit,
because the hardware does not support this.
However, this means that we must also clear the queued flag when we sync
back a LR where the state on the physical distributor went from active
to inactive because the guest deactivated the interrupt. At this point
we must also check if the interrupt is pending on the distributor, and
tell the VGIC to queue it again if it is.
Since these actions on the sync path are extremely close to those for
level-triggered interrupts, rename process_level_irq to
process_queued_irq, allowing it to cater for both cases.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
The arch timer currently uses edge-triggered semantics in the sense that
the line is never sampled by the vgic and lowering the line from the
timer to the vgic doesn't have any effect on the pending state of
virtual interrupts in the vgic. This means that we do not support a
guest with the otherwise valid behavior of (1) disable interrupts (2)
enable the timer (3) disable the timer (4) enable interrupts. Such a
guest would validly not expect to see any interrupts on real hardware,
but will see interrupts on KVM.
This patch fixes this shortcoming through the following series of
changes.
First, we change the flow of the timer/vgic sync/flush operations. Now
the timer is always flushed/synced before the vgic, because the vgic
samples the state of the timer output. This has the implication that we
move the timer operations in to non-preempible sections, but that is
fine after the previous commit getting rid of hrtimer schedules on every
entry/exit.
Second, we change the internal behavior of the timer, letting the timer
keep track of its previous output state, and only lower/raise the line
to the vgic when the state changes. Note that in theory this could have
been accomplished more simply by signalling the vgic every time the
state *potentially* changed, but we don't want to be hitting the vgic
more often than necessary.
Third, we get rid of the use of the map->active field in the vgic and
instead simply set the interrupt as active on the physical distributor
whenever the input to the GIC is asserted and conversely clear the
physical active state when the input to the GIC is deasserted.
Fourth, and finally, we now initialize the timer PPIs (and all the other
unused PPIs for now), to be level-triggered, and modify the sync code to
sample the line state on HW sync and re-inject a new interrupt if it is
still pending at that time.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
We currently initialize the SGIs to be enabled in the VGIC code, but we
use the VGIC_NR_PPIS define for this purpose, instead of the the more
natural VGIC_NR_SGIS. Change this slightly confusing use of the
defines.
Note: This should have no functional change, as both names are defined
to the number 16.
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
The GICD_ICFGR allows the bits for the SGIs and PPIs to be read only.
We currently simulate this behavior by writing a hardcoded value to the
register for the SGIs and PPIs on every write of these bits to the
register (ignoring what the guest actually wrote), and by writing the
same value as the reset value to the register.
This is a bit counter-intuitive, as the register is RO for these bits,
and we can just implement it that way, allowing us to control the value
of the bits purely in the reset code.
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Currently vgic_process_maintenance() processes dealing with a completed
level-triggered interrupt directly, but we are soon going to reuse this
logic for level-triggered mapped interrupts with the HW bit set, so
move this logic into a separate static function.
Probably the most scary part of this commit is convincing yourself that
the current flow is safe compared to the old one. In the following I
try to list the changes and why they are harmless:
Move vgic_irq_clear_queued after kvm_notify_acked_irq:
Harmless because the only potential effect of clearing the queued
flag wrt. kvm_set_irq is that vgic_update_irq_pending does not set
the pending bit on the emulated CPU interface or in the
pending_on_cpu bitmask if the function is called with level=1.
However, the point of kvm_notify_acked_irq is to call kvm_set_irq
with level=0, and we set the queued flag again in
__kvm_vgic_sync_hwstate later on if the level is stil high.
Move vgic_set_lr before kvm_notify_acked_irq:
Also, harmless because the LR are cpu-local operations and
kvm_notify_acked only affects the dist
Move vgic_dist_irq_clear_soft_pend after kvm_notify_acked_irq:
Also harmless, because now we check the level state in the
clear_soft_pend function and lower the pending bits if the level is
low.
Reviewed-by: Eric Auger <eric.auger@linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
We currently schedule a soft timer every time we exit the guest if the
timer did not expire while running the guest. This is really not
necessary, because the only work we do in the timer work function is to
kick the vcpu.
Kicking the vcpu does two things:
(1) If the vpcu thread is on a waitqueue, make it runnable and remove it
from the waitqueue.
(2) If the vcpu is running on a different physical CPU from the one
doing the kick, it sends a reschedule IPI.
The second case cannot happen, because the soft timer is only ever
scheduled when the vcpu is not running. The first case is only relevant
when the vcpu thread is on a waitqueue, which is only the case when the
vcpu thread has called kvm_vcpu_block().
Therefore, we only need to make sure a timer is scheduled for
kvm_vcpu_block(), which we do by encapsulating all calls to
kvm_vcpu_block() with kvm_timer_{un}schedule calls.
Additionally, we only schedule a soft timer if the timer is enabled and
unmasked, since it is useless otherwise.
Note that theoretically userspace can use the SET_ONE_REG interface to
change registers that should cause the timer to fire, even if the vcpu
is blocked without a scheduled timer, but this case was not supported
before this patch and we leave it for future work for now.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
We currently do a single update of the vgic state when the distributor
enable/disable control register is accessed and then bypass updating the
state for as long as the distributor remains disabled.
This is incorrect, because updating the state does not consider the
distributor enable bit, and this you can end up in a situation where an
interrupt is marked as pending on the CPU interface, but not pending on
the distributor, which is an impossible state to be in, and triggers a
warning. Consider for example the following sequence of events:
1. An interrupt is marked as pending on the distributor
- the interrupt is also forwarded to the CPU interface
2. The guest turns off the distributor (it's about to do a reboot)
- we stop updating the CPU interface state from now on
3. The guest disables the pending interrupt
- we remove the pending state from the distributor, but don't touch
the CPU interface, see point 2.
Since the distributor disable bit really means that no interrupts should
be forwarded to the CPU interface, we modify the code to keep updating
the internal VGIC state, but always set the CPU interface pending bits
to zero when the distributor is disabled.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
When a guest reboots or offlines/onlines CPUs, it is not uncommon for it
to clear the pending and active states of an interrupt through the
emulated VGIC distributor. However, since the architected timers are
defined by the architecture to be level triggered and the guest
rightfully expects them to be that, but we emulate them as
edge-triggered, we have to mimic level-triggered behavior for an
edge-triggered virtual implementation.
We currently do not signal the VGIC when the map->active field is true,
because it indicates that the guest has already been signalled of the
interrupt as required. Normally this field is set to false when the
guest deactivates the virtual interrupt through the sync path.
We also need to catch the case where the guest deactivates the interrupt
through the emulated distributor, again allowing guests to boot even if
the original virtual timer signal hit before the guest's GIC
initialization sequence is run.
Reviewed-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
We have an interesting issue when the guest disables the timer interrupt
on the VGIC, which happens when turning VCPUs off using PSCI, for
example.
The problem is that because the guest disables the virtual interrupt at
the VGIC level, we never inject interrupts to the guest and therefore
never mark the interrupt as active on the physical distributor. The
host also never takes the timer interrupt (we only use the timer device
to trigger a guest exit and everything else is done in software), so the
interrupt does not become active through normal means.
The result is that we keep entering the guest with a programmed timer
that will always fire as soon as we context switch the hardware timer
state and run the guest, preventing forward progress for the VCPU.
Since the active state on the physical distributor is really part of the
timer logic, it is the job of our virtual arch timer driver to manage
this state.
The timer->map->active boolean field indicates whether we have signalled
this interrupt to the vgic and if that interrupt is still pending or
active. As long as that is the case, the hardware doesn't have to
generate physical interrupts and therefore we mark the interrupt as
active on the physical distributor.
We also have to restore the pending state of an interrupt that was
queued to an LR but was retired from the LR for some reason, while
remaining pending in the LR.
Cc: Marc Zyngier <marc.zyngier@arm.com>
Reported-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
When lowering a level-triggered line from userspace, we forgot to lower
the pending bit on the emulated CPU interface and we also did not
re-compute the pending_on_cpu bitmap for the CPU affected by the change.
Update vgic_update_irq_pending() to fix the two issues above and also
raise a warning in vgic_quue_irq_to_lr if we encounter an interrupt
pending on a CPU which is neither marked active nor pending.
[ Commit text reworked completely - Christoffer ]
Signed-off-by: Pavel Fedin <p.fedin@samsung.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Hardware virtualisation of GICv3 is only supported by 64bit hosts for
the moment. Some VGICv3 bits are missing from the 32bit side, and this
patch allows to still be able to build 32bit hosts when CONFIG_ARM_GIC_V3
is selected.
To this end, we introduce a new option, CONFIG_KVM_ARM_VGIC_V3, that is
only enabled on the 64bit side. The selection is done unconditionally
because CONFIG_ARM_GIC_V3 is always enabled on arm64.
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
This patch removes config option of KVM_ARM_MAX_VCPUS,
and like other ARCHs, just choose the maximum allowed
value from hardware, and follows the reasons:
1) from distribution view, the option has to be
defined as the max allowed value because it need to
meet all kinds of virtulization applications and
need to support most of SoCs;
2) using a bigger value doesn't introduce extra memory
consumption, and the help text in Kconfig isn't accurate
because kvm_vpu structure isn't allocated until request
of creating VCPU is sent from QEMU;
3) the main effect is that the field of vcpus[] in 'struct kvm'
becomes a bit bigger(sizeof(void *) per vcpu) and need more cache
lines to hold the structure, but 'struct kvm' is one generic struct,
and it has worked well on other ARCHs already in this way. Also,
the world switch frequecy is often low, for example, it is ~2000
when running kernel building load in VM from APM xgene KVM host,
so the effect is very small, and the difference can't be observed
in my test at all.
Cc: Dann Frazier <dann.frazier@canonical.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Provide a better quality of implementation and be architecture compliant
on ARMv7 for the architected timer by resetting the CNTV_CTL to 0 on
reset of the timer.
This change alone fixes the UEFI reset issue reported by Laszlo back in
February.
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Drew Jones <drjones@redhat.com>
Cc: Wei Huang <wei@redhat.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
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>
We currently set the physical active state only when we *inject* a new
pending virtual interrupt, but this is actually not correct, because we
could have been preempted and run something else on the system that
resets the active state to clear. This causes us to run the VM with the
timer set to fire, but without setting the physical active state.
The solution is to always check the LR configurations, and we if have a
mapped interrupt in the LR in either the pending or active state
(virtual), then set the physical active state.
Acked-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>
In order to remove the crude hack where we sneak the masked bit
into the timer's control register, make use of the phys_irq_map
API control the active state of the interrupt.
This causes some limited changes to allow for potential error
propagation.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Virtual interrupts mapped to a HW interrupt should only be triggered
from inside the kernel. Otherwise, you could end up confusing the
kernel (and the GIC's) state machine.
Rearrange the injection path so that kvm_vgic_inject_irq is
used for non-mapped interrupts, and kvm_vgic_inject_mapped_irq is
used for mapped interrupts. The latter should only be called from
inside the kernel (timer, irqfd).
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
In order to control the active state of an interrupt, introduce
a pair of accessors allowing the state to be set/queried.
This only affects the logical state, and the HW state will only be
applied at world-switch time.
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
To allow a HW interrupt to be injected into a guest, we lookup the
guest virtual interrupt in the irq_phys_map list, and if we have
a match, encode both interrupts in the LR.
We also mark the interrupt as "active" at the host distributor level.
On guest EOI on the virtual interrupt, the host interrupt will be
deactivated.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
In order to be able to feed physical interrupts to a guest, we need
to be able to establish the virtual-physical mapping between the two
worlds.
The mappings are kept in a set of RCU lists, indexed by virtual interrupts.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
We only set the irq_queued flag for level interrupts, meaning
that "!vgic_irq_is_queued(vcpu, irq)" is a good enough predicate
for all interrupts.
This will allow us to inject edge HW interrupts, for which the
state ACTIVE+PENDING is not allowed.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Now that struct vgic_lr supports the LR_HW bit and carries a hwirq
field, we can encode that information into the list registers.
This patch provides implementations for both GICv2 and GICv3.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
- CPU ops and PSCI (Power State Coordination Interface) refactoring
following the merging of the arm64 ACPI support, together with
handling of Trusted (secure) OS instances
- Using fixmap for permanent FDT mapping, removing the initial dtb
placement requirements (within 512MB from the start of the kernel
image). This required moving the FDT self reservation out of the
memreserve processing
- Idmap (1:1 mapping used for MMU on/off) handling clean-up
- Removing flush_cache_all() - not safe on ARM unless the MMU is off.
Last stages of CPU power down/up are handled by firmware already
- "Alternatives" (run-time code patching) refactoring and support for
immediate branch patching, GICv3 CPU interface access
- User faults handling clean-up
And some fixes:
- Fix for VDSO building with broken ELF toolchains
- Fixing another case of init_mm.pgd usage for user mappings (during
ASID roll-over broadcasting)
- Fix for FPSIMD reloading after CPU hotplug
- Fix for missing syscall trace exit
- Workaround for .inst asm bug
- Compat fix for switching the user tls tpidr_el0 register
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=YeGl
-----END PGP SIGNATURE-----
Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 updates from Catalin Marinas:
"Mostly refactoring/clean-up:
- CPU ops and PSCI (Power State Coordination Interface) refactoring
following the merging of the arm64 ACPI support, together with
handling of Trusted (secure) OS instances
- Using fixmap for permanent FDT mapping, removing the initial dtb
placement requirements (within 512MB from the start of the kernel
image). This required moving the FDT self reservation out of the
memreserve processing
- Idmap (1:1 mapping used for MMU on/off) handling clean-up
- Removing flush_cache_all() - not safe on ARM unless the MMU is off.
Last stages of CPU power down/up are handled by firmware already
- "Alternatives" (run-time code patching) refactoring and support for
immediate branch patching, GICv3 CPU interface access
- User faults handling clean-up
And some fixes:
- Fix for VDSO building with broken ELF toolchains
- Fix another case of init_mm.pgd usage for user mappings (during
ASID roll-over broadcasting)
- Fix for FPSIMD reloading after CPU hotplug
- Fix for missing syscall trace exit
- Workaround for .inst asm bug
- Compat fix for switching the user tls tpidr_el0 register"
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (42 commits)
arm64: use private ratelimit state along with show_unhandled_signals
arm64: show unhandled SP/PC alignment faults
arm64: vdso: work-around broken ELF toolchains in Makefile
arm64: kernel: rename __cpu_suspend to keep it aligned with arm
arm64: compat: print compat_sp instead of sp
arm64: mm: Fix freeing of the wrong memmap entries with !SPARSEMEM_VMEMMAP
arm64: entry: fix context tracking for el0_sp_pc
arm64: defconfig: enable memtest
arm64: mm: remove reference to tlb.S from comment block
arm64: Do not attempt to use init_mm in reset_context()
arm64: KVM: Switch vgic save/restore to alternative_insn
arm64: alternative: Introduce feature for GICv3 CPU interface
arm64: psci: fix !CONFIG_HOTPLUG_CPU build warning
arm64: fix bug for reloading FPSIMD state after CPU hotplug.
arm64: kernel thread don't need to save fpsimd context.
arm64: fix missing syscall trace exit
arm64: alternative: Work around .inst assembler bugs
arm64: alternative: Merge alternative-asm.h into alternative.h
arm64: alternative: Allow immediate branch as alternative instruction
arm64: Rework alternate sequence for ARM erratum 845719
...
Back in the days, vgic.c used to have an intimate knowledge of
the actual GICv2. These days, this has been abstracted away into
hardware-specific backends.
Remove the now useless arm-gic.h #include directive, making it
clear that GICv2 specific code doesn't belong here.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Commit fd1d0ddf2a (KVM: arm/arm64: check IRQ number on userland
injection) rightly limited the range of interrupts userspace can
inject in a guest, but failed to consider the (unlikely) case where
a guest is configured with 1024 interrupts.
In this case, interrupts ranging from 1020 to 1023 are unuseable,
as they have a special meaning for the GIC CPU interface.
Make sure that these number cannot be used as an IRQ. Also delete
a redundant (and similarily buggy) check in kvm_set_irq.
Reported-by: Peter Maydell <peter.maydell@linaro.org>
Cc: Andre Przywara <andre.przywara@arm.com>
Cc: <stable@vger.kernel.org> # 4.1, 4.0, 3.19, 3.18
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
If a GICv3-enabled guest tries to configure Group0, we print a
warning on the console (because we don't support Group0 interrupts).
This is fairly pointless, and would allow a guest to spam the
console. Let's just drop the warning.
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
So far, we configured the world-switch by having a small array
of pointers to the save and restore functions, depending on the
GIC used on the platform.
Loading these values each time is a bit silly (they never change),
and it makes sense to rely on the instruction patching instead.
This leads to a nice cleanup of the code.
Acked-by: Will Deacon <will.deacon@arm.com>
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>
Commit 47a98b15ba ("arm/arm64: KVM: support for un-queuing active
IRQs") introduced handling of the GICD_I[SC]ACTIVER registers,
but only for the GICv2 emulation. For the sake of completeness and
as this is a pre-requisite for save/restore of the GICv3 distributor
state, we should also emulate their handling in the distributor and
redistributor frames of an emulated GICv3.
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
When userland injects a SPI via the KVM_IRQ_LINE ioctl we currently
only check it against a fixed limit, which historically is set
to 127. With the new dynamic IRQ allocation the effective limit may
actually be smaller (64).
So when now a malicious or buggy userland injects a SPI in that
range, we spill over on our VGIC bitmaps and bytemaps memory.
I could trigger a host kernel NULL pointer dereference with current
mainline by injecting some bogus IRQ number from a hacked kvmtool:
-----------------
....
DEBUG: kvm_vgic_inject_irq(kvm, cpu=0, irq=114, level=1)
DEBUG: vgic_update_irq_pending(kvm, cpu=0, irq=114, level=1)
DEBUG: IRQ #114 still in the game, writing to bytemap now...
Unable to handle kernel NULL pointer dereference at virtual address 00000000
pgd = ffffffc07652e000
[00000000] *pgd=00000000f658b003, *pud=00000000f658b003, *pmd=0000000000000000
Internal error: Oops: 96000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 1053 Comm: lkvm-msi-irqinj Not tainted 4.0.0-rc7+ #3027
Hardware name: FVP Base (DT)
task: ffffffc0774e9680 ti: ffffffc0765a8000 task.ti: ffffffc0765a8000
PC is at kvm_vgic_inject_irq+0x234/0x310
LR is at kvm_vgic_inject_irq+0x30c/0x310
pc : [<ffffffc0000ae0a8>] lr : [<ffffffc0000ae180>] pstate: 80000145
.....
So this patch fixes this by checking the SPI number against the
actual limit. Also we remove the former legacy hard limit of
127 in the ioctl code.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
CC: <stable@vger.kernel.org> # 4.0, 3.19, 3.18
[maz: wrap KVM_ARM_IRQ_GIC_MAX with #ifndef __KERNEL__,
as suggested by Christopher Covington]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
irqfd/arm curently does not support routing. kvm_irq_map_gsi is
supposed to return all the routing entries associated with the
provided gsi and return the number of those entries. We should
return 0 at this point.
Signed-off-by: Eric Auger <eric.auger@linaro.org>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Currently we have struct kvm_exit_mmio for encapsulating MMIO abort
data to be passed on from syndrome decoding all the way down to the
VGIC register handlers. Now as we switch the MMIO handling to be
routed through the KVM MMIO bus, it does not make sense anymore to
use that structure already from the beginning. So we keep the data in
local variables until we put them into the kvm_io_bus framework.
Then we fill kvm_exit_mmio in the VGIC only, making it a VGIC private
structure. On that way we replace the data buffer in that structure
with a pointer pointing to a single location in a local variable, so
we get rid of some copying on the way.
With all of the virtual GIC emulation code now being registered with
the kvm_io_bus, we can remove all of the old MMIO handling code and
its dispatching functionality.
I didn't bother to rename kvm_exit_mmio (to vgic_mmio or something),
because that touches a lot of code lines without any good reason.
This is based on an original patch by Nikolay.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Cc: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Using the framework provided by the recent vgic.c changes, we
register a kvm_io_bus device on mapping the virtual GICv3 resources.
The distributor mapping is pretty straight forward, but the
redistributors need some more love, since they need to be tagged with
the respective redistributor (read: VCPU) they are connected with.
We use the kvm_io_bus framework to register one devices per VCPU.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Currently we handle the redistributor registers in two separate MMIO
regions, one for the overall behaviour and SPIs and one for the
SGIs/PPIs. That latter forces the creation of _two_ KVM I/O bus
devices for each redistributor.
Since the spec mandates those two pages to be contigious, we could as
well merge them and save the churn with the second KVM I/O bus device.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Using the framework provided by the recent vgic.c changes we register
a kvm_io_bus device when initializing the virtual GICv2.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Currently we use a lot of VGIC specific code to do the MMIO
dispatching.
Use the previous reworks to add kvm_io_bus style MMIO handlers.
Those are not yet called by the MMIO abort handler, also the actual
VGIC emulator function do not make use of it yet, but will be enabled
with the following patches.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
The vgic_find_range() function in vgic.c takes a struct kvm_exit_mmio
argument, but actually only used the length field in there. Since we
need to get rid of that structure in that part of the code anyway,
let's rework the function (and it's callers) to pass the length
argument to the function directly.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
The name "kvm_mmio_range" is a bit bold, given that it only covers
the VGIC's MMIO ranges. To avoid confusion with kvm_io_range, rename
it to vgic_io_range.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
When a VCPU is no longer running, we currently check to see if it has a
timer scheduled in the future, and if it does, we schedule a host
hrtimer to notify is in case the timer expires while the VCPU is still
not running. When the hrtimer fires, we mask the guest's timer and
inject the timer IRQ (still relying on the guest unmasking the time when
it receives the IRQ).
This is all good and fine, but when migration a VM (checkpoint/restore)
this introduces a race. It is unlikely, but possible, for the following
sequence of events to happen:
1. Userspace stops the VM
2. Hrtimer for VCPU is scheduled
3. Userspace checkpoints the VGIC state (no pending timer interrupts)
4. The hrtimer fires, schedules work in a workqueue
5. Workqueue function runs, masks the timer and injects timer interrupt
6. Userspace checkpoints the timer state (timer masked)
At restore time, you end up with a masked timer without any timer
interrupts and your guest halts never receiving timer interrupts.
Fix this by only kicking the VCPU in the workqueue function, and sample
the expired state of the timer when entering the guest again and inject
the interrupt and mask the timer only then.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Migrating active interrupts causes the active state to be lost
completely. This implements some additional bitmaps to track the active
state on the distributor and export this to user space.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
This helps re-factor away some of the repetitive code and makes the code
flow more nicely.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
There is an interesting bug in the vgic code, which manifests itself
when the KVM run loop has a signal pending or needs a vmid generation
rollover after having disabled interrupts but before actually switching
to the guest.
In this case, we flush the vgic as usual, but we sync back the vgic
state and exit to userspace before entering the guest. The consequence
is that we will be syncing the list registers back to the software model
using the GICH_ELRSR and GICH_EISR from the last execution of the guest,
potentially overwriting a list register containing an interrupt.
This showed up during migration testing where we would capture a state
where the VM has masked the arch timer but there were no interrupts,
resulting in a hung test.
Cc: Marc Zyngier <marc.zyngier@arm.com>
Reported-by: Alex Bennee <alex.bennee@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Christoffer Dall