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author | 2019-10-27 14:41:59 +0000 | |
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committer | 2019-10-28 16:20:58 +0000 | |
commit | 8e01d9a396e6db153d94a6004e6473d9ff251a6a (patch) | |
tree | a7b0bba9a91ac8544ee28ba101864f5a8486e87e /virt/kvm/arm | |
parent | KVM: arm64: Don't set HCR_EL2.TVM when S2FWB is supported (diff) | |
download | linux-8e01d9a396e6db153d94a6004e6473d9ff251a6a.tar.gz linux-8e01d9a396e6db153d94a6004e6473d9ff251a6a.tar.bz2 linux-8e01d9a396e6db153d94a6004e6473d9ff251a6a.zip |
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
Diffstat (limited to 'virt/kvm/arm')
-rw-r--r-- | virt/kvm/arm/arm.c | 12 | ||||
-rw-r--r-- | virt/kvm/arm/vgic/vgic-v3.c | 4 | ||||
-rw-r--r-- | virt/kvm/arm/vgic/vgic-v4.c | 55 | ||||
-rw-r--r-- | virt/kvm/arm/vgic/vgic.c | 4 | ||||
-rw-r--r-- | virt/kvm/arm/vgic/vgic.h | 2 |
5 files changed, 38 insertions, 39 deletions
diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c index 86c6aa1cb58e..bd2afcf9a13f 100644 --- a/virt/kvm/arm/arm.c +++ b/virt/kvm/arm/arm.c @@ -322,20 +322,24 @@ void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) /* * If we're about to block (most likely because we've just hit a * WFI), we need to sync back the state of the GIC CPU interface - * so that we have the lastest PMR and group enables. This ensures + * so that we have the latest PMR and group enables. This ensures * that kvm_arch_vcpu_runnable has up-to-date data to decide * whether we have pending interrupts. + * + * For the same reason, we want to tell GICv4 that we need + * doorbells to be signalled, should an interrupt become pending. */ preempt_disable(); kvm_vgic_vmcr_sync(vcpu); + vgic_v4_put(vcpu, true); preempt_enable(); - - kvm_vgic_v4_enable_doorbell(vcpu); } void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) { - kvm_vgic_v4_disable_doorbell(vcpu); + preempt_disable(); + vgic_v4_load(vcpu); + preempt_enable(); } int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu) diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c index 8d69f007dd0c..48307a9eb1d8 100644 --- a/virt/kvm/arm/vgic/vgic-v3.c +++ b/virt/kvm/arm/vgic/vgic-v3.c @@ -664,6 +664,8 @@ void vgic_v3_load(struct kvm_vcpu *vcpu) if (has_vhe()) __vgic_v3_activate_traps(vcpu); + + WARN_ON(vgic_v4_load(vcpu)); } void vgic_v3_vmcr_sync(struct kvm_vcpu *vcpu) @@ -676,6 +678,8 @@ void vgic_v3_vmcr_sync(struct kvm_vcpu *vcpu) void vgic_v3_put(struct kvm_vcpu *vcpu) { + WARN_ON(vgic_v4_put(vcpu, false)); + vgic_v3_vmcr_sync(vcpu); kvm_call_hyp(__vgic_v3_save_aprs, vcpu); diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c index 477af6aebb97..7e1f3202968a 100644 --- a/virt/kvm/arm/vgic/vgic-v4.c +++ b/virt/kvm/arm/vgic/vgic-v4.c @@ -85,6 +85,10 @@ static irqreturn_t vgic_v4_doorbell_handler(int irq, void *info) { struct kvm_vcpu *vcpu = info; + /* We got the message, no need to fire again */ + if (!irqd_irq_disabled(&irq_to_desc(irq)->irq_data)) + disable_irq_nosync(irq); + vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last = true; kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu); kvm_vcpu_kick(vcpu); @@ -192,20 +196,30 @@ void vgic_v4_teardown(struct kvm *kvm) its_vm->vpes = NULL; } -int vgic_v4_sync_hwstate(struct kvm_vcpu *vcpu) +int vgic_v4_put(struct kvm_vcpu *vcpu, bool need_db) { - if (!vgic_supports_direct_msis(vcpu->kvm)) + struct its_vpe *vpe = &vcpu->arch.vgic_cpu.vgic_v3.its_vpe; + struct irq_desc *desc = irq_to_desc(vpe->irq); + + if (!vgic_supports_direct_msis(vcpu->kvm) || !vpe->resident) return 0; - return its_schedule_vpe(&vcpu->arch.vgic_cpu.vgic_v3.its_vpe, false); + /* + * If blocking, a doorbell is required. Undo the nested + * disable_irq() calls... + */ + while (need_db && irqd_irq_disabled(&desc->irq_data)) + enable_irq(vpe->irq); + + return its_schedule_vpe(vpe, false); } -int vgic_v4_flush_hwstate(struct kvm_vcpu *vcpu) +int vgic_v4_load(struct kvm_vcpu *vcpu) { - int irq = vcpu->arch.vgic_cpu.vgic_v3.its_vpe.irq; + struct its_vpe *vpe = &vcpu->arch.vgic_cpu.vgic_v3.its_vpe; int err; - if (!vgic_supports_direct_msis(vcpu->kvm)) + if (!vgic_supports_direct_msis(vcpu->kvm) || vpe->resident) return 0; /* @@ -214,11 +228,14 @@ int vgic_v4_flush_hwstate(struct kvm_vcpu *vcpu) * doc in drivers/irqchip/irq-gic-v4.c to understand how this * turns into a VMOVP command at the ITS level. */ - err = irq_set_affinity(irq, cpumask_of(smp_processor_id())); + err = irq_set_affinity(vpe->irq, cpumask_of(smp_processor_id())); if (err) return err; - err = its_schedule_vpe(&vcpu->arch.vgic_cpu.vgic_v3.its_vpe, true); + /* Disabled the doorbell, as we're about to enter the guest */ + disable_irq_nosync(vpe->irq); + + err = its_schedule_vpe(vpe, true); if (err) return err; @@ -226,9 +243,7 @@ int vgic_v4_flush_hwstate(struct kvm_vcpu *vcpu) * Now that the VPE is resident, let's get rid of a potential * doorbell interrupt that would still be pending. */ - err = irq_set_irqchip_state(irq, IRQCHIP_STATE_PENDING, false); - - return err; + return irq_set_irqchip_state(vpe->irq, IRQCHIP_STATE_PENDING, false); } static struct vgic_its *vgic_get_its(struct kvm *kvm, @@ -335,21 +350,3 @@ out: mutex_unlock(&its->its_lock); return ret; } - -void kvm_vgic_v4_enable_doorbell(struct kvm_vcpu *vcpu) -{ - if (vgic_supports_direct_msis(vcpu->kvm)) { - int irq = vcpu->arch.vgic_cpu.vgic_v3.its_vpe.irq; - if (irq) - enable_irq(irq); - } -} - -void kvm_vgic_v4_disable_doorbell(struct kvm_vcpu *vcpu) -{ - if (vgic_supports_direct_msis(vcpu->kvm)) { - int irq = vcpu->arch.vgic_cpu.vgic_v3.its_vpe.irq; - if (irq) - disable_irq(irq); - } -} diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c index 45a870cb63f5..99b02ca730a8 100644 --- a/virt/kvm/arm/vgic/vgic.c +++ b/virt/kvm/arm/vgic/vgic.c @@ -857,8 +857,6 @@ void kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu) { struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu; - WARN_ON(vgic_v4_sync_hwstate(vcpu)); - /* An empty ap_list_head implies used_lrs == 0 */ if (list_empty(&vcpu->arch.vgic_cpu.ap_list_head)) return; @@ -882,8 +880,6 @@ static inline void vgic_restore_state(struct kvm_vcpu *vcpu) /* Flush our emulation state into the GIC hardware before entering the guest. */ void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu) { - WARN_ON(vgic_v4_flush_hwstate(vcpu)); - /* * If there are no virtual interrupts active or pending for this * VCPU, then there is no work to do and we can bail out without diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h index 83066a81b16a..c7fefd6b1c80 100644 --- a/virt/kvm/arm/vgic/vgic.h +++ b/virt/kvm/arm/vgic/vgic.h @@ -316,7 +316,5 @@ void vgic_its_invalidate_cache(struct kvm *kvm); bool vgic_supports_direct_msis(struct kvm *kvm); int vgic_v4_init(struct kvm *kvm); void vgic_v4_teardown(struct kvm *kvm); -int vgic_v4_sync_hwstate(struct kvm_vcpu *vcpu); -int vgic_v4_flush_hwstate(struct kvm_vcpu *vcpu); #endif |