1 files changed, 91 insertions, 0 deletions

diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
index 840f4586796f..cf6832365345 100644
--- a/arch/riscv/kvm/vcpu.c
+++ b/arch/riscv/kvm/vcpu.c
@@ -38,6 +38,86 @@ const struct kvm_stats_header kvm_vcpu_stats_header = {
 		       sizeof(kvm_vcpu_stats_desc),
 };
 
+#ifdef CONFIG_FPU
+static void kvm_riscv_vcpu_fp_reset(struct kvm_vcpu *vcpu)
+{
+	unsigned long isa = vcpu->arch.isa;
+	struct kvm_cpu_context *cntx = &vcpu->arch.guest_context;
+
+	cntx->sstatus &= ~SR_FS;
+	if (riscv_isa_extension_available(&isa, f) ||
+	    riscv_isa_extension_available(&isa, d))
+		cntx->sstatus |= SR_FS_INITIAL;
+	else
+		cntx->sstatus |= SR_FS_OFF;
+}
+
+static void kvm_riscv_vcpu_fp_clean(struct kvm_cpu_context *cntx)
+{
+	cntx->sstatus &= ~SR_FS;
+	cntx->sstatus |= SR_FS_CLEAN;
+}
+
+static void kvm_riscv_vcpu_guest_fp_save(struct kvm_cpu_context *cntx,
+					 unsigned long isa)
+{
+	if ((cntx->sstatus & SR_FS) == SR_FS_DIRTY) {
+		if (riscv_isa_extension_available(&isa, d))
+			__kvm_riscv_fp_d_save(cntx);
+		else if (riscv_isa_extension_available(&isa, f))
+			__kvm_riscv_fp_f_save(cntx);
+		kvm_riscv_vcpu_fp_clean(cntx);
+	}
+}
+
+static void kvm_riscv_vcpu_guest_fp_restore(struct kvm_cpu_context *cntx,
+					    unsigned long isa)
+{
+	if ((cntx->sstatus & SR_FS) != SR_FS_OFF) {
+		if (riscv_isa_extension_available(&isa, d))
+			__kvm_riscv_fp_d_restore(cntx);
+		else if (riscv_isa_extension_available(&isa, f))
+			__kvm_riscv_fp_f_restore(cntx);
+		kvm_riscv_vcpu_fp_clean(cntx);
+	}
+}
+
+static void kvm_riscv_vcpu_host_fp_save(struct kvm_cpu_context *cntx)
+{
+	/* No need to check host sstatus as it can be modified outside */
+	if (riscv_isa_extension_available(NULL, d))
+		__kvm_riscv_fp_d_save(cntx);
+	else if (riscv_isa_extension_available(NULL, f))
+		__kvm_riscv_fp_f_save(cntx);
+}
+
+static void kvm_riscv_vcpu_host_fp_restore(struct kvm_cpu_context *cntx)
+{
+	if (riscv_isa_extension_available(NULL, d))
+		__kvm_riscv_fp_d_restore(cntx);
+	else if (riscv_isa_extension_available(NULL, f))
+		__kvm_riscv_fp_f_restore(cntx);
+}
+#else
+static void kvm_riscv_vcpu_fp_reset(struct kvm_vcpu *vcpu)
+{
+}
+static void kvm_riscv_vcpu_guest_fp_save(struct kvm_cpu_context *cntx,
+					 unsigned long isa)
+{
+}
+static void kvm_riscv_vcpu_guest_fp_restore(struct kvm_cpu_context *cntx,
+					    unsigned long isa)
+{
+}
+static void kvm_riscv_vcpu_host_fp_save(struct kvm_cpu_context *cntx)
+{
+}
+static void kvm_riscv_vcpu_host_fp_restore(struct kvm_cpu_context *cntx)
+{
+}
+#endif
+
 #define KVM_RISCV_ISA_ALLOWED	(riscv_isa_extension_mask(a) | \
 				 riscv_isa_extension_mask(c) | \
 				 riscv_isa_extension_mask(d) | \
@@ -58,6 +138,8 @@ static void kvm_riscv_reset_vcpu(struct kvm_vcpu *vcpu)
 
 	memcpy(cntx, reset_cntx, sizeof(*cntx));
 
+	kvm_riscv_vcpu_fp_reset(vcpu);
+
 	kvm_riscv_vcpu_timer_reset(vcpu);
 
 	WRITE_ONCE(vcpu->arch.irqs_pending, 0);
@@ -192,6 +274,7 @@ static int kvm_riscv_vcpu_set_reg_config(struct kvm_vcpu *vcpu,
 			vcpu->arch.isa = reg_val;
 			vcpu->arch.isa &= riscv_isa_extension_base(NULL);
 			vcpu->arch.isa &= KVM_RISCV_ISA_ALLOWED;
+			kvm_riscv_vcpu_fp_reset(vcpu);
 		} else {
 			return -EOPNOTSUPP;
 		}
@@ -593,6 +676,10 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 
 	kvm_riscv_vcpu_timer_restore(vcpu);
 
+	kvm_riscv_vcpu_host_fp_save(&vcpu->arch.host_context);
+	kvm_riscv_vcpu_guest_fp_restore(&vcpu->arch.guest_context,
+					vcpu->arch.isa);
+
 	vcpu->cpu = cpu;
 }
 
@@ -602,6 +689,10 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
 
 	vcpu->cpu = -1;
 
+	kvm_riscv_vcpu_guest_fp_save(&vcpu->arch.guest_context,
+				     vcpu->arch.isa);
+	kvm_riscv_vcpu_host_fp_restore(&vcpu->arch.host_context);
+
 	csr_write(CSR_HGATP, 0);
 
 	csr->vsstatus = csr_read(CSR_VSSTATUS);