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author | Paul Mackerras <paulus@ozlabs.org> | 2018-10-08 16:30:48 +1100 |
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committer | Michael Ellerman <mpe@ellerman.id.au> | 2018-10-09 16:04:27 +1100 |
commit | d24ea8a7336a2c392728e2cf909d607a680feb7b (patch) | |
tree | 1bc989b981481e26fb0197e8c8f013eeff490b21 /arch/powerpc/kvm/book3s_xics.c | |
parent | e7b17d50471a8bfddf7c976c7d3a68104272b2f3 (diff) | |
download | lwn-d24ea8a7336a2c392728e2cf909d607a680feb7b.tar.gz lwn-d24ea8a7336a2c392728e2cf909d607a680feb7b.zip |
KVM: PPC: Book3S: Simplify external interrupt handling
Currently we use two bits in the vcpu pending_exceptions bitmap to
indicate that an external interrupt is pending for the guest, one
for "one-shot" interrupts that are cleared when delivered, and one
for interrupts that persist until cleared by an explicit action of
the OS (e.g. an acknowledge to an interrupt controller). The
BOOK3S_IRQPRIO_EXTERNAL bit is used for one-shot interrupt requests
and BOOK3S_IRQPRIO_EXTERNAL_LEVEL is used for persisting interrupts.
In practice BOOK3S_IRQPRIO_EXTERNAL never gets used, because our
Book3S platforms generally, and pseries in particular, expect
external interrupt requests to persist until they are acknowledged
at the interrupt controller. That combined with the confusion
introduced by having two bits for what is essentially the same thing
makes it attractive to simplify things by only using one bit. This
patch does that.
With this patch there is only BOOK3S_IRQPRIO_EXTERNAL, and by default
it has the semantics of a persisting interrupt. In order to avoid
breaking the ABI, we introduce a new "external_oneshot" flag which
preserves the behaviour of the KVM_INTERRUPT ioctl with the
KVM_INTERRUPT_SET argument.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kvm/book3s_xics.c')
-rw-r--r-- | arch/powerpc/kvm/book3s_xics.c | 11 |
1 files changed, 4 insertions, 7 deletions
diff --git a/arch/powerpc/kvm/book3s_xics.c b/arch/powerpc/kvm/book3s_xics.c index b8356cdc0c04..d9ba1b06d0f5 100644 --- a/arch/powerpc/kvm/book3s_xics.c +++ b/arch/powerpc/kvm/book3s_xics.c @@ -310,7 +310,7 @@ static inline bool icp_try_update(struct kvmppc_icp *icp, */ if (new.out_ee) { kvmppc_book3s_queue_irqprio(icp->vcpu, - BOOK3S_INTERRUPT_EXTERNAL_LEVEL); + BOOK3S_INTERRUPT_EXTERNAL); if (!change_self) kvmppc_fast_vcpu_kick(icp->vcpu); } @@ -593,8 +593,7 @@ static noinline unsigned long kvmppc_h_xirr(struct kvm_vcpu *vcpu) u32 xirr; /* First, remove EE from the processor */ - kvmppc_book3s_dequeue_irqprio(icp->vcpu, - BOOK3S_INTERRUPT_EXTERNAL_LEVEL); + kvmppc_book3s_dequeue_irqprio(icp->vcpu, BOOK3S_INTERRUPT_EXTERNAL); /* * ICP State: Accept_Interrupt @@ -754,8 +753,7 @@ static noinline void kvmppc_h_cppr(struct kvm_vcpu *vcpu, unsigned long cppr) * We can remove EE from the current processor, the update * transaction will set it again if needed */ - kvmppc_book3s_dequeue_irqprio(icp->vcpu, - BOOK3S_INTERRUPT_EXTERNAL_LEVEL); + kvmppc_book3s_dequeue_irqprio(icp->vcpu, BOOK3S_INTERRUPT_EXTERNAL); do { old_state = new_state = READ_ONCE(icp->state); @@ -1167,8 +1165,7 @@ int kvmppc_xics_set_icp(struct kvm_vcpu *vcpu, u64 icpval) * Deassert the CPU interrupt request. * icp_try_update will reassert it if necessary. */ - kvmppc_book3s_dequeue_irqprio(icp->vcpu, - BOOK3S_INTERRUPT_EXTERNAL_LEVEL); + kvmppc_book3s_dequeue_irqprio(icp->vcpu, BOOK3S_INTERRUPT_EXTERNAL); /* * Note that if we displace an interrupt from old_state.xisr, |