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authorMarc Zyngier <maz@kernel.org>2019-10-27 14:41:59 +0000
committerMarc Zyngier <maz@kernel.org>2019-10-28 16:20:58 +0000
commit8e01d9a396e6db153d94a6004e6473d9ff251a6a (patch)
treea7b0bba9a91ac8544ee28ba101864f5a8486e87e /virt
parent5c401308017f256ae9de804b4a1c65be1d390571 (diff)
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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')
-rw-r--r--virt/kvm/arm/arm.c12
-rw-r--r--virt/kvm/arm/vgic/vgic-v3.c4
-rw-r--r--virt/kvm/arm/vgic/vgic-v4.c55
-rw-r--r--virt/kvm/arm/vgic/vgic.c4
-rw-r--r--virt/kvm/arm/vgic/vgic.h2
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