[RFC PATCH 2/6] RISC-V: KVM: Transfer the physical address of MRIF to iommu-ir

[fangyu . yu]

From: Fangyu Yu <fangyu.yu@xxxxxxxxxxxxxxxxx>

According to the RISC-V IOMMU Spec, an IOMMU may optionally
support memory-resident interrupt files (MRIFs).

When the guest interrupt files are used up, we transfer the
physical address of MRIF to iommu-ir, and enable MRIF  mode
if the iommu-ir supports.

Signed-off-by: Fangyu Yu <fangyu.yu@xxxxxxxxxxxxxxxxx>
---
 arch/riscv/kvm/aia_imsic.c | 23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/arch/riscv/kvm/aia_imsic.c b/arch/riscv/kvm/aia_imsic.c
index 8f5703d9112a..e91164742fd0 100644
--- a/arch/riscv/kvm/aia_imsic.c
+++ b/arch/riscv/kvm/aia_imsic.c
@@ -21,6 +21,8 @@
 
 #define IMSIC_MAX_EIX	(IMSIC_MAX_ID / BITS_PER_TYPE(u64))
 
+static int kvm_riscv_vcpu_irq_update(struct kvm_vcpu *vcpu);
+
 struct imsic_mrif_eix {
 	unsigned long eip[BITS_PER_TYPE(u64) / BITS_PER_LONG];
 	unsigned long eie[BITS_PER_TYPE(u64) / BITS_PER_LONG];
@@ -717,7 +719,8 @@ void kvm_riscv_vcpu_aia_imsic_release(struct kvm_vcpu *vcpu)
 				 vcpu->arch.aia_context.imsic_addr,
 				 IMSIC_MMIO_PAGE_SZ);
 
-	/* TODO: Purge the IOMMU mapping ??? */
+	/* Update the IOMMU mapping */
+	kvm_riscv_vcpu_irq_update(vcpu);
 
 	/*
 	 * At this point, all interrupt producers have been re-directed
@@ -795,13 +798,14 @@ int kvm_arch_update_irqfd_routing(struct kvm *kvm, unsigned int host_irq,
 
 			read_lock_irqsave(&imsic->vsfile_lock, flags);
 
-			if (WARN_ON_ONCE(imsic->vsfile_cpu < 0)) {
-				read_unlock_irqrestore(&imsic->vsfile_lock, flags);
-				goto out;
+			if (imsic->vsfile_cpu < 0) {
+				vcpu_info.hpa = imsic->swfile_pa;
+				vcpu_info.mrif = true;
+			} else {
+				vcpu_info.hpa = imsic->vsfile_pa;
+				vcpu_info.mrif = false;
 			}
 
-			vcpu_info.hpa = imsic->vsfile_pa;
-
 			ret = irq_set_vcpu_affinity(host_irq, &vcpu_info);
 			if (ret) {
 				read_unlock_irqrestore(&imsic->vsfile_lock, flags);
@@ -844,6 +848,13 @@ static int kvm_riscv_vcpu_irq_update(struct kvm_vcpu *vcpu)
 		if (!irqfd->producer)
 			continue;
 		host_irq = irqfd->producer->irq;
+
+		if (imsic->vsfile_cpu < 0) {
+			vcpu_info.hpa = imsic->swfile_pa;
+			vcpu_info.mrif = true;
+		} else {
+			vcpu_info.mrif = false;
+		}
 		ret = irq_set_vcpu_affinity(host_irq, &vcpu_info);
 		if (ret) {
 			spin_unlock_irq(&kvm->irqfds.lock);
-- 
2.49.0