[RFC PATCH v4 4/5] RISC-V: KVM: add support for SBI_FWFT_PTE_AD_HW_UPDATING

[Yong-Xuan Wang]

Add support for SBI_FWFT_PTE_AD_HW_UPDATING to set the PTE A/D bits
updating behavior for Guest/VM.

Signed-off-by: Yong-Xuan Wang <yongxuan.wang at sifive.com>
---
 arch/riscv/include/asm/kvm_vcpu_sbi_fwft.h |  2 +-
 arch/riscv/kvm/vcpu_sbi_fwft.c             | 38 +++++++++++++++++++++-
 2 files changed, 38 insertions(+), 2 deletions(-)

diff --git a/arch/riscv/include/asm/kvm_vcpu_sbi_fwft.h b/arch/riscv/include/asm/kvm_vcpu_sbi_fwft.h
index 7b7bcc5c8fee..3614a44e0a4a 100644
--- a/arch/riscv/include/asm/kvm_vcpu_sbi_fwft.h
+++ b/arch/riscv/include/asm/kvm_vcpu_sbi_fwft.h
@@ -11,7 +11,7 @@
 
 #include <asm/sbi.h>
 
-#define KVM_SBI_FWFT_FEATURE_COUNT	1
+#define KVM_SBI_FWFT_FEATURE_COUNT	2
 
 struct kvm_sbi_fwft_config;
 struct kvm_vcpu;
diff --git a/arch/riscv/kvm/vcpu_sbi_fwft.c b/arch/riscv/kvm/vcpu_sbi_fwft.c
index 89ec263c250d..14ef74023340 100644
--- a/arch/riscv/kvm/vcpu_sbi_fwft.c
+++ b/arch/riscv/kvm/vcpu_sbi_fwft.c
@@ -71,6 +71,36 @@ static int kvm_sbi_fwft_get_misaligned_delegation(struct kvm_vcpu *vcpu,
 	return SBI_SUCCESS;
 }
 
+static int kvm_sbi_fwft_adue_supported(struct kvm_vcpu *vcpu)
+{
+	if (!riscv_isa_extension_available(vcpu->arch.isa, SVADU))
+		return SBI_ERR_NOT_SUPPORTED;
+
+	return 0;
+}
+
+static int kvm_sbi_fwft_set_adue(struct kvm_vcpu *vcpu, struct kvm_sbi_fwft_config *conf,
+				 unsigned long value)
+{
+	if (value)
+		vcpu->arch.cfg.henvcfg |= ENVCFG_ADUE;
+	else
+		vcpu->arch.cfg.henvcfg &= ~ENVCFG_ADUE;
+
+	return SBI_SUCCESS;
+}
+
+static int kvm_sbi_fwft_get_adue(struct kvm_vcpu *vcpu, struct kvm_sbi_fwft_config *conf,
+				 unsigned long *value)
+{
+	if (!riscv_isa_extension_available(vcpu->arch.isa, SVADU))
+		return SBI_ERR_NOT_SUPPORTED;
+
+	*value = !!(vcpu->arch.cfg.henvcfg & ENVCFG_ADUE);
+
+	return SBI_SUCCESS;
+}
+
 static struct kvm_sbi_fwft_config *
 kvm_sbi_fwft_get_config(struct kvm_vcpu *vcpu, enum sbi_fwft_feature_t feature)
 {
@@ -177,7 +207,13 @@ static const struct kvm_sbi_fwft_feature features[] = {
 		.supported = kvm_sbi_fwft_misaligned_delegation_supported,
 		.set = kvm_sbi_fwft_set_misaligned_delegation,
 		.get = kvm_sbi_fwft_get_misaligned_delegation,
-	}
+	},
+	{
+		.id = SBI_FWFT_PTE_AD_HW_UPDATING,
+		.supported = kvm_sbi_fwft_adue_supported,
+		.set = kvm_sbi_fwft_set_adue,
+		.get = kvm_sbi_fwft_get_adue,
+	},
 };
 
 static_assert(ARRAY_SIZE(features) == KVM_SBI_FWFT_FEATURE_COUNT);
-- 
2.17.1