5 files changed, 80 insertions, 0 deletions

diff --git a/arch/riscv/include/asm/kvm_vcpu_sbi.h b/arch/riscv/include/asm/kvm_vcpu_sbi.h
index b96705258cf9..4ed6203cdd30 100644
--- a/arch/riscv/include/asm/kvm_vcpu_sbi.h
+++ b/arch/riscv/include/asm/kvm_vcpu_sbi.h
@@ -85,6 +85,7 @@ extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_rfence;
 extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_srst;
 extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_hsm;
 extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_dbcn;
+extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_susp;
 extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_sta;
 extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_experimental;
 extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_vendor;
diff --git a/arch/riscv/include/uapi/asm/kvm.h b/arch/riscv/include/uapi/asm/kvm.h
index 3482c9a73d1b..24e22f6e3a47 100644
--- a/arch/riscv/include/uapi/asm/kvm.h
+++ b/arch/riscv/include/uapi/asm/kvm.h
@@ -198,6 +198,7 @@ enum KVM_RISCV_SBI_EXT_ID {
 	KVM_RISCV_SBI_EXT_VENDOR,
 	KVM_RISCV_SBI_EXT_DBCN,
 	KVM_RISCV_SBI_EXT_STA,
+	KVM_RISCV_SBI_EXT_SUSP,
 	KVM_RISCV_SBI_EXT_MAX,
 };
 
diff --git a/arch/riscv/kvm/Makefile b/arch/riscv/kvm/Makefile
index 0fb1840c3e0a..4e0bba91d284 100644
--- a/arch/riscv/kvm/Makefile
+++ b/arch/riscv/kvm/Makefile
@@ -30,6 +30,7 @@ kvm-y += vcpu_sbi_hsm.o
 kvm-$(CONFIG_RISCV_PMU_SBI) += vcpu_sbi_pmu.o
 kvm-y += vcpu_sbi_replace.o
 kvm-y += vcpu_sbi_sta.o
+kvm-y += vcpu_sbi_system.o
 kvm-$(CONFIG_RISCV_SBI_V01) += vcpu_sbi_v01.o
 kvm-y += vcpu_switch.o
 kvm-y += vcpu_timer.o
diff --git a/arch/riscv/kvm/vcpu_sbi.c b/arch/riscv/kvm/vcpu_sbi.c
index 6e704ed86a83..d1c83a77735e 100644
--- a/arch/riscv/kvm/vcpu_sbi.c
+++ b/arch/riscv/kvm/vcpu_sbi.c
@@ -71,6 +71,10 @@ static const struct kvm_riscv_sbi_extension_entry sbi_ext[] = {
 		.ext_ptr = &vcpu_sbi_ext_dbcn,
 	},
 	{
+		.ext_idx = KVM_RISCV_SBI_EXT_SUSP,
+		.ext_ptr = &vcpu_sbi_ext_susp,
+	},
+	{
 		.ext_idx = KVM_RISCV_SBI_EXT_STA,
 		.ext_ptr = &vcpu_sbi_ext_sta,
 	},
diff --git a/arch/riscv/kvm/vcpu_sbi_system.c b/arch/riscv/kvm/vcpu_sbi_system.c
new file mode 100644
index 000000000000..5d55e08791fa
--- /dev/null
+++ b/arch/riscv/kvm/vcpu_sbi_system.c
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2024 Ventana Micro Systems Inc.
+ */
+
+#include <linux/kvm_host.h>
+
+#include <asm/kvm_vcpu_sbi.h>
+#include <asm/sbi.h>
+
+static int kvm_sbi_ext_susp_handler(struct kvm_vcpu *vcpu, struct kvm_run *run,
+				    struct kvm_vcpu_sbi_return *retdata)
+{
+	struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
+	struct kvm_cpu_context *reset_cntx;
+	unsigned long funcid = cp->a6;
+	unsigned long hva, i;
+	struct kvm_vcpu *tmp;
+
+	switch (funcid) {
+	case SBI_EXT_SUSP_SYSTEM_SUSPEND:
+		if (cp->a0 != SBI_SUSP_SLEEP_TYPE_SUSPEND_TO_RAM) {
+			retdata->err_val = SBI_ERR_INVALID_PARAM;
+			return 0;
+		}
+
+		if (!(cp->sstatus & SR_SPP)) {
+			retdata->err_val = SBI_ERR_FAILURE;
+			return 0;
+		}
+
+		hva = kvm_vcpu_gfn_to_hva_prot(vcpu, cp->a1 >> PAGE_SHIFT, NULL);
+		if (kvm_is_error_hva(hva)) {
+			retdata->err_val = SBI_ERR_INVALID_ADDRESS;
+			return 0;
+		}
+
+		kvm_for_each_vcpu(i, tmp, vcpu->kvm) {
+			if (tmp == vcpu)
+				continue;
+			if (!kvm_riscv_vcpu_stopped(tmp)) {
+				retdata->err_val = SBI_ERR_DENIED;
+				return 0;
+			}
+		}
+
+		spin_lock(&vcpu->arch.reset_cntx_lock);
+		reset_cntx = &vcpu->arch.guest_reset_context;
+		reset_cntx->sepc = cp->a1;
+		reset_cntx->a0 = vcpu->vcpu_id;
+		reset_cntx->a1 = cp->a2;
+		spin_unlock(&vcpu->arch.reset_cntx_lock);
+
+		kvm_make_request(KVM_REQ_VCPU_RESET, vcpu);
+
+		/* userspace provides the suspend implementation */
+		kvm_riscv_vcpu_sbi_forward(vcpu, run);
+		retdata->uexit = true;
+		break;
+	default:
+		retdata->err_val = SBI_ERR_NOT_SUPPORTED;
+		break;
+	}
+
+	return 0;
+}
+
+const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_susp = {
+	.extid_start = SBI_EXT_SUSP,
+	.extid_end = SBI_EXT_SUSP,
+	.default_disabled = true,
+	.handler = kvm_sbi_ext_susp_handler,
+};