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  1. 20 5月, 2016 10 次提交
  3. 03 5月, 2016 1 次提交
  5. 09 3月, 2016 2 次提交
  7. 01 3月, 2016 14 次提交
  9. 14 12月, 2015 1 次提交
  11. 25 11月, 2015 1 次提交
    • C
      KVM: arm/arm64: arch_timer: Preserve physical dist. active state on LR.active · 0e3dfda9
      由 Christoffer Dall 提交于 
      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: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>
      0e3dfda9
  13. 04 11月, 2015 2 次提交
  15. 23 10月, 2015 3 次提交
    • M
      KVM: arm: Do not indent the arguments of DECLARE_BITMAP · 5fdf876d
      由 Michal Marek 提交于 
      Besides being a coding style issue, it confuses make tags:

ctags: Warning: include/kvm/arm_vgic.h:307: null expansion of name pattern "\1"
ctags: Warning: include/kvm/arm_vgic.h:308: null expansion of name pattern "\1"
ctags: Warning: include/kvm/arm_vgic.h:309: null expansion of name pattern "\1"
ctags: Warning: include/kvm/arm_vgic.h:317: null expansion of name pattern "\1"

Cc: kvmarm@lists.cs.columbia.edu
Signed-off-by: NMichal Marek <mmarek@suse.com>
Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>
      5fdf876d
    • C
      arm/arm64: KVM: Rework the arch timer to use level-triggered semantics · 4b4b4512
      由 Christoffer Dall 提交于 
      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: NChristoffer Dall <christoffer.dall@linaro.org>
      4b4b4512
    • C
      arm/arm64: KVM: arch_timer: Only schedule soft timer on vcpu_block · d35268da
      由 Christoffer Dall 提交于 
      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: NChristoffer Dall <christoffer.dall@linaro.org>
      d35268da
  17. 10 10月, 2015 1 次提交
  19. 17 9月, 2015 1 次提交
    • M
      arm/arm64: KVM: Remove 'config KVM_ARM_MAX_VCPUS' · ef748917
      由 Ming Lei 提交于 
      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: NMing Lei <ming.lei@canonical.com>
Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
      ef748917
  21. 12 8月, 2015 4 次提交