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Date: Fri, 27 May 2022 16:02:43 +0800
From: Gavin Shan <gshan@...hat.com>
To: kvmarm@...ts.cs.columbia.edu
Cc: maz@...nel.org, linux-kernel@...r.kernel.org, eauger@...hat.com,
oupton@...gle.com, Jonathan.Cameron@...wei.com,
pbonzini@...hat.com, vkuznets@...hat.com, will@...nel.org,
james.morse@....com, mark.rutland@....com,
shannon.zhaosl@...il.com, shijie@...eremail.onmicrosoft.com,
shan.gavin@...il.com
Subject: [PATCH v7 12/22] KVM: arm64: Support event injection and delivery
This supports event injection, delivery and cancellation. The event
is injected and cancelled by kvm_sdei_{inject, cancel}_event(). For
event delivery, kvm_sdei_deliver_event() is added to accommodate
KVM_REQ_SDEI request.
The KVM_REQ_SDEI request can be raised in several situation:
* PE is unmasked
* Event is enabled
* Completion of currently running event or handler on receiving
EVENT_COMPLETE or EVENT_COMPLETE_AND_RESUME hypercall, which
will be supported in the subsequent patch.
Signed-off-by: Gavin Shan <gshan@...hat.com>
---
arch/arm64/include/asm/kvm_sdei.h | 4 +
arch/arm64/kvm/arm.c | 3 +
arch/arm64/kvm/sdei.c | 123 ++++++++++++++++++++++++++++++
3 files changed, 130 insertions(+)
diff --git a/arch/arm64/include/asm/kvm_sdei.h b/arch/arm64/include/asm/kvm_sdei.h
index 609338b17478..735d9ac1a5a2 100644
--- a/arch/arm64/include/asm/kvm_sdei.h
+++ b/arch/arm64/include/asm/kvm_sdei.h
@@ -64,6 +64,10 @@ struct kvm_sdei_vcpu {
/* APIs */
int kvm_sdei_call(struct kvm_vcpu *vcpu);
+int kvm_sdei_inject_event(struct kvm_vcpu *vcpu,
+ unsigned int num, bool immediate);
+int kvm_sdei_cancel_event(struct kvm_vcpu *vcpu, unsigned int num);
+void kvm_sdei_deliver_event(struct kvm_vcpu *vcpu);
void kvm_sdei_create_vcpu(struct kvm_vcpu *vcpu);
void kvm_sdei_destroy_vcpu(struct kvm_vcpu *vcpu);
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index e9516f951e7b..06cb5e38634e 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -720,6 +720,9 @@ static int check_vcpu_requests(struct kvm_vcpu *vcpu)
if (kvm_check_request(KVM_REQ_VCPU_RESET, vcpu))
kvm_reset_vcpu(vcpu);
+ if (kvm_check_request(KVM_REQ_SDEI, vcpu))
+ kvm_sdei_deliver_event(vcpu);
+
/*
* Clear IRQ_PENDING requests that were made to guarantee
* that a VCPU sees new virtual interrupts.
diff --git a/arch/arm64/kvm/sdei.c b/arch/arm64/kvm/sdei.c
index 42ba6f97b168..36a72c1750fc 100644
--- a/arch/arm64/kvm/sdei.c
+++ b/arch/arm64/kvm/sdei.c
@@ -266,6 +266,129 @@ int kvm_sdei_call(struct kvm_vcpu *vcpu)
return 1;
}
+int kvm_sdei_inject_event(struct kvm_vcpu *vcpu,
+ unsigned int num,
+ bool immediate)
+{
+ struct kvm_sdei_vcpu *vsdei = vcpu->arch.sdei;
+
+ if (!vsdei)
+ return -EPERM;
+
+ if (num >= KVM_NR_SDEI_EVENTS || !test_bit(num, &vsdei->registered))
+ return -ENOENT;
+
+ /*
+ * The event may be expected to be delivered immediately. There
+ * are several cases we can't do this:
+ *
+ * (1) The PE has been masked from any events.
+ * (2) The event isn't enabled yet.
+ * (3) There are any pending or running events.
+ */
+ if (immediate &&
+ ((vcpu->arch.flags & KVM_ARM64_SDEI_MASKED) ||
+ !test_bit(num, &vsdei->enabled) ||
+ vsdei->pending || vsdei->running))
+ return -EBUSY;
+
+ set_bit(num, &vsdei->pending);
+ if (!(vcpu->arch.flags & KVM_ARM64_SDEI_MASKED) &&
+ test_bit(num, &vsdei->enabled))
+ kvm_make_request(KVM_REQ_SDEI, vcpu);
+
+ return 0;
+}
+
+int kvm_sdei_cancel_event(struct kvm_vcpu *vcpu, unsigned int num)
+{
+ struct kvm_sdei_vcpu *vsdei = vcpu->arch.sdei;
+
+ if (!vsdei)
+ return -EPERM;
+
+ if (num >= KVM_NR_SDEI_EVENTS || !test_bit(num, &vsdei->registered))
+ return -ENOENT;
+
+ if (test_bit(num, &vsdei->running))
+ return -EBUSY;
+
+ clear_bit(num, &vsdei->pending);
+
+ return 0;
+}
+
+void kvm_sdei_deliver_event(struct kvm_vcpu *vcpu)
+{
+ struct kvm_sdei_vcpu *vsdei = vcpu->arch.sdei;
+ struct kvm_sdei_event_context *ctxt = &vsdei->ctxt;
+ unsigned int num, i;
+ unsigned long pstate;
+
+ if (!vsdei || (vcpu->arch.flags & KVM_ARM64_SDEI_MASKED))
+ return;
+
+ /*
+ * All supported events have normal priority. So the currently
+ * running event can't be preempted by any one else.
+ */
+ if (vsdei->running)
+ return;
+
+ /* Select next pending event to be delivered */
+ num = 0;
+ while (num < KVM_NR_SDEI_EVENTS) {
+ num = find_next_bit(&vsdei->pending, KVM_NR_SDEI_EVENTS, num);
+ if (test_bit(num, &vsdei->enabled))
+ break;
+ }
+
+ if (num >= KVM_NR_SDEI_EVENTS)
+ return;
+
+ /*
+ * Save the interrupted context. We might have pending request
+ * to adjust PC. Lets adjust it now so that the resume address
+ * is correct when COMPLETE or COMPLETE_AND_RESUME hypercall
+ * is handled.
+ */
+ __kvm_adjust_pc(vcpu);
+ ctxt->pc = *vcpu_pc(vcpu);
+ ctxt->pstate = *vcpu_cpsr(vcpu);
+ for (i = 0; i < ARRAY_SIZE(ctxt->regs); i++)
+ ctxt->regs[i] = vcpu_get_reg(vcpu, i);
+
+ /*
+ * Inject event. The following registers are modified according
+ * to the specification.
+ *
+ * x0: event number
+ * x1: argument specified when the event is registered
+ * x2: PC of the interrupted context
+ * x3: PSTATE of the interrupted context
+ * PC: event handler
+ * PSTATE: Cleared nRW bit, but D/A/I/F bits are set
+ */
+ for (i = 0; i < ARRAY_SIZE(ctxt->regs); i++)
+ vcpu_set_reg(vcpu, i, 0);
+
+ vcpu_set_reg(vcpu, 0, num);
+ vcpu_set_reg(vcpu, 1, vsdei->handlers[num].ep_arg);
+ vcpu_set_reg(vcpu, 2, ctxt->pc);
+ vcpu_set_reg(vcpu, 3, ctxt->pstate);
+
+ pstate = ctxt->pstate;
+ pstate &= ~(PSR_MODE32_BIT | PSR_MODE_MASK);
+ pstate |= (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT | PSR_MODE_EL1h);
+
+ *vcpu_cpsr(vcpu) = pstate;
+ *vcpu_pc(vcpu) = vsdei->handlers[num].ep_addr;
+
+ /* Update event states */
+ clear_bit(num, &vsdei->pending);
+ set_bit(num, &vsdei->running);
+}
+
void kvm_sdei_create_vcpu(struct kvm_vcpu *vcpu)
{
struct kvm_sdei_vcpu *vsdei;
--
2.23.0
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