RISC-V: KVM: Initial skeletal support for AIA

To incrementally implement AIA support, we first add minimal skeletal
support which only compiles and detects AIA hardware support at the
boot-time but does not provide any functionality.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>

1 files changed, 40 insertions, 5 deletions

diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
index 02b49cb94561..b46e9cc92938 100644
--- a/arch/riscv/kvm/vcpu.c
+++ b/arch/riscv/kvm/vcpu.c
@@ -137,6 +137,8 @@ static void kvm_riscv_reset_vcpu(struct kvm_vcpu *vcpu)
 
 	kvm_riscv_vcpu_timer_reset(vcpu);
 
+	kvm_riscv_vcpu_aia_reset(vcpu);
+
 	WRITE_ONCE(vcpu->arch.irqs_pending, 0);
 	WRITE_ONCE(vcpu->arch.irqs_pending_mask, 0);
 
@@ -159,6 +161,7 @@ int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id)
 
 int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
 {
+	int rc;
 	struct kvm_cpu_context *cntx;
 	struct kvm_vcpu_csr *reset_csr = &vcpu->arch.guest_reset_csr;
 	unsigned long host_isa, i;
@@ -201,6 +204,11 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
 	/* setup performance monitoring */
 	kvm_riscv_vcpu_pmu_init(vcpu);
 
+	/* Setup VCPU AIA */
+	rc = kvm_riscv_vcpu_aia_init(vcpu);
+	if (rc)
+		return rc;
+
 	/* Reset VCPU */
 	kvm_riscv_reset_vcpu(vcpu);
 
@@ -220,6 +228,9 @@ void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
 
 void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
 {
+	/* Cleanup VCPU AIA context */
+	kvm_riscv_vcpu_aia_deinit(vcpu);
+
 	/* Cleanup VCPU timer */
 	kvm_riscv_vcpu_timer_deinit(vcpu);
 
@@ -741,6 +752,9 @@ void kvm_riscv_vcpu_flush_interrupts(struct kvm_vcpu *vcpu)
 		csr->hvip &= ~mask;
 		csr->hvip |= val;
 	}
+
+	/* Flush AIA high interrupts */
+	kvm_riscv_vcpu_aia_flush_interrupts(vcpu);
 }
 
 void kvm_riscv_vcpu_sync_interrupts(struct kvm_vcpu *vcpu)
@@ -766,6 +780,9 @@ void kvm_riscv_vcpu_sync_interrupts(struct kvm_vcpu *vcpu)
 		}
 	}
 
+	/* Sync-up AIA high interrupts */
+	kvm_riscv_vcpu_aia_sync_interrupts(vcpu);
+
 	/* Sync-up timer CSRs */
 	kvm_riscv_vcpu_timer_sync(vcpu);
 }
@@ -802,10 +819,15 @@ int kvm_riscv_vcpu_unset_interrupt(struct kvm_vcpu *vcpu, unsigned int irq)
 
 bool kvm_riscv_vcpu_has_interrupts(struct kvm_vcpu *vcpu, unsigned long mask)
 {
-	unsigned long ie = ((vcpu->arch.guest_csr.vsie & VSIP_VALID_MASK)
-			    << VSIP_TO_HVIP_SHIFT) & mask;
+	unsigned long ie;
+
+	ie = ((vcpu->arch.guest_csr.vsie & VSIP_VALID_MASK)
+		<< VSIP_TO_HVIP_SHIFT) & mask;
+	if (READ_ONCE(vcpu->arch.irqs_pending) & ie)
+		return true;
 
-	return (READ_ONCE(vcpu->arch.irqs_pending) & ie) ? true : false;
+	/* Check AIA high interrupts */
+	return kvm_riscv_vcpu_aia_has_interrupts(vcpu, mask);
 }
 
 void kvm_riscv_vcpu_power_off(struct kvm_vcpu *vcpu)
@@ -901,6 +923,8 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 	kvm_riscv_vcpu_guest_fp_restore(&vcpu->arch.guest_context,
 					vcpu->arch.isa);
 
+	kvm_riscv_vcpu_aia_load(vcpu, cpu);
+
 	vcpu->cpu = cpu;
 }
 
@@ -910,6 +934,8 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
 
 	vcpu->cpu = -1;
 
+	kvm_riscv_vcpu_aia_put(vcpu);
+
 	kvm_riscv_vcpu_guest_fp_save(&vcpu->arch.guest_context,
 				     vcpu->arch.isa);
 	kvm_riscv_vcpu_host_fp_restore(&vcpu->arch.host_context);
@@ -977,6 +1003,7 @@ static void kvm_riscv_update_hvip(struct kvm_vcpu *vcpu)
 	struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr;
 
 	csr_write(CSR_HVIP, csr->hvip);
+	kvm_riscv_vcpu_aia_update_hvip(vcpu);
 }
 
 /*
@@ -1049,6 +1076,15 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
 
 		kvm_riscv_check_vcpu_requests(vcpu);
 
+		preempt_disable();
+
+		/* Update AIA HW state before entering guest */
+		ret = kvm_riscv_vcpu_aia_update(vcpu);
+		if (ret <= 0) {
+			preempt_enable();
+			continue;
+		}
+
 		local_irq_disable();
 
 		/*
@@ -1077,6 +1113,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
 		    xfer_to_guest_mode_work_pending()) {
 			vcpu->mode = OUTSIDE_GUEST_MODE;
 			local_irq_enable();
+			preempt_enable();
 			kvm_vcpu_srcu_read_lock(vcpu);
 			continue;
 		}
@@ -1110,8 +1147,6 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
 		/* Syncup interrupts state with HW */
 		kvm_riscv_vcpu_sync_interrupts(vcpu);
 
-		preempt_disable();
-
 		/*
 		 * We must ensure that any pending interrupts are taken before
 		 * we exit guest timing so that timer ticks are accounted as