RISC-V: KVM: Factor-out FP virtualization into separate sources

The timer and SBI virtualization is already in separate sources.
In future, we will have vector and AIA virtualization also added
as separate sources.

To align with above described modularity, we factor-out FP
virtualization into separate sources.

Signed-off-by: Anup Patel <[e-mail]>
Message-Id: <[e-mail]>
Signed-off-by: Paolo Bonzini <[e-mail]>

arch/riscv/include/asm/kvm_host.h

···
 #include <linux/types.h>
 #include <linux/kvm.h>
 #include <linux/kvm_types.h>
+#include <asm/kvm_vcpu_fp.h>
 #include <asm/kvm_vcpu_timer.h>
 
 #ifdef CONFIG_64BIT
···
 			struct kvm_cpu_trap *trap);
 
 void __kvm_riscv_switch_to(struct kvm_vcpu_arch *vcpu_arch);
-void __kvm_riscv_fp_f_save(struct kvm_cpu_context *context);
-void __kvm_riscv_fp_f_restore(struct kvm_cpu_context *context);
-void __kvm_riscv_fp_d_save(struct kvm_cpu_context *context);
-void __kvm_riscv_fp_d_restore(struct kvm_cpu_context *context);
 
 int kvm_riscv_vcpu_set_interrupt(struct kvm_vcpu *vcpu, unsigned int irq);
 int kvm_riscv_vcpu_unset_interrupt(struct kvm_vcpu *vcpu, unsigned int irq);

arch/riscv/include/asm/kvm_vcpu_fp.h

···
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ *     Atish Patra <[e-mail]>
+ *     Anup Patel <[e-mail]>
+ */
+
+#ifndef __KVM_VCPU_RISCV_FP_H
+#define __KVM_VCPU_RISCV_FP_H
+
+#include <linux/types.h>
+
+struct kvm_cpu_context;
+
+#ifdef CONFIG_FPU
+void __kvm_riscv_fp_f_save(struct kvm_cpu_context *context);
+void __kvm_riscv_fp_f_restore(struct kvm_cpu_context *context);
+void __kvm_riscv_fp_d_save(struct kvm_cpu_context *context);
+void __kvm_riscv_fp_d_restore(struct kvm_cpu_context *context);
+
+void kvm_riscv_vcpu_fp_reset(struct kvm_vcpu *vcpu);
+void kvm_riscv_vcpu_guest_fp_save(struct kvm_cpu_context *cntx,
+				  unsigned long isa);
+void kvm_riscv_vcpu_guest_fp_restore(struct kvm_cpu_context *cntx,
+				     unsigned long isa);
+void kvm_riscv_vcpu_host_fp_save(struct kvm_cpu_context *cntx);
+void kvm_riscv_vcpu_host_fp_restore(struct kvm_cpu_context *cntx);
+#else
+static inline void kvm_riscv_vcpu_fp_reset(struct kvm_vcpu *vcpu)
+{
+}
+static inline void kvm_riscv_vcpu_guest_fp_save(struct kvm_cpu_context *cntx,
+						unsigned long isa)
+{
+}
+static inline void kvm_riscv_vcpu_guest_fp_restore(
+					struct kvm_cpu_context *cntx,
+					unsigned long isa)
+{
+}
+static inline void kvm_riscv_vcpu_host_fp_save(struct kvm_cpu_context *cntx)
+{
+}
+static inline void kvm_riscv_vcpu_host_fp_restore(
+					struct kvm_cpu_context *cntx)
+{
+}
+#endif
+
+int kvm_riscv_vcpu_get_reg_fp(struct kvm_vcpu *vcpu,
+			      const struct kvm_one_reg *reg,
+			      unsigned long rtype);
+int kvm_riscv_vcpu_set_reg_fp(struct kvm_vcpu *vcpu,
+			      const struct kvm_one_reg *reg,
+			      unsigned long rtype);
+
+#endif

arch/riscv/kvm/Makefile

···
 kvm-y += mmu.o
 kvm-y += vcpu.o
 kvm-y += vcpu_exit.o
+kvm-y += vcpu_fp.o
 kvm-y += vcpu_switch.o
 kvm-y += vcpu_sbi.o
 kvm-y += vcpu_timer.o

arch/riscv/kvm/vcpu.c

···
 		       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) | \
···
 
 	if (reg_num == KVM_REG_RISCV_CSR_REG(sip))
 		WRITE_ONCE(vcpu->arch.irqs_pending_mask, 0);
-
-	return 0;
-}
-
-static int kvm_riscv_vcpu_get_reg_fp(struct kvm_vcpu *vcpu,
-				     const struct kvm_one_reg *reg,
-				     unsigned long rtype)
-{
-	struct kvm_cpu_context *cntx = &vcpu->arch.guest_context;
-	unsigned long isa = vcpu->arch.isa;
-	unsigned long __user *uaddr =
-			(unsigned long __user *)(unsigned long)reg->addr;
-	unsigned long reg_num = reg->id & ~(KVM_REG_ARCH_MASK |
-					    KVM_REG_SIZE_MASK |
-					    rtype);
-	void *reg_val;
-
-	if ((rtype == KVM_REG_RISCV_FP_F) &&
-	    riscv_isa_extension_available(&isa, f)) {
-		if (KVM_REG_SIZE(reg->id) != sizeof(u32))
-			return -EINVAL;
-		if (reg_num == KVM_REG_RISCV_FP_F_REG(fcsr))
-			reg_val = &cntx->fp.f.fcsr;
-		else if ((KVM_REG_RISCV_FP_F_REG(f[0]) <= reg_num) &&
-			  reg_num <= KVM_REG_RISCV_FP_F_REG(f[31]))
-			reg_val = &cntx->fp.f.f[reg_num];
-		else
-			return -EINVAL;
-	} else if ((rtype == KVM_REG_RISCV_FP_D) &&
-		   riscv_isa_extension_available(&isa, d)) {
-		if (reg_num == KVM_REG_RISCV_FP_D_REG(fcsr)) {
-			if (KVM_REG_SIZE(reg->id) != sizeof(u32))
-				return -EINVAL;
-			reg_val = &cntx->fp.d.fcsr;
-		} else if ((KVM_REG_RISCV_FP_D_REG(f[0]) <= reg_num) &&
-			   reg_num <= KVM_REG_RISCV_FP_D_REG(f[31])) {
-			if (KVM_REG_SIZE(reg->id) != sizeof(u64))
-				return -EINVAL;
-			reg_val = &cntx->fp.d.f[reg_num];
-		} else
-			return -EINVAL;
-	} else
-		return -EINVAL;
-
-	if (copy_to_user(uaddr, reg_val, KVM_REG_SIZE(reg->id)))
-		return -EFAULT;
-
-	return 0;
-}
-
-static int kvm_riscv_vcpu_set_reg_fp(struct kvm_vcpu *vcpu,
-				     const struct kvm_one_reg *reg,
-				     unsigned long rtype)
-{
-	struct kvm_cpu_context *cntx = &vcpu->arch.guest_context;
-	unsigned long isa = vcpu->arch.isa;
-	unsigned long __user *uaddr =
-			(unsigned long __user *)(unsigned long)reg->addr;
-	unsigned long reg_num = reg->id & ~(KVM_REG_ARCH_MASK |
-					    KVM_REG_SIZE_MASK |
-					    rtype);
-	void *reg_val;
-
-	if ((rtype == KVM_REG_RISCV_FP_F) &&
-	    riscv_isa_extension_available(&isa, f)) {
-		if (KVM_REG_SIZE(reg->id) != sizeof(u32))
-			return -EINVAL;
-		if (reg_num == KVM_REG_RISCV_FP_F_REG(fcsr))
-			reg_val = &cntx->fp.f.fcsr;
-		else if ((KVM_REG_RISCV_FP_F_REG(f[0]) <= reg_num) &&
-			  reg_num <= KVM_REG_RISCV_FP_F_REG(f[31]))
-			reg_val = &cntx->fp.f.f[reg_num];
-		else
-			return -EINVAL;
-	} else if ((rtype == KVM_REG_RISCV_FP_D) &&
-		   riscv_isa_extension_available(&isa, d)) {
-		if (reg_num == KVM_REG_RISCV_FP_D_REG(fcsr)) {
-			if (KVM_REG_SIZE(reg->id) != sizeof(u32))
-				return -EINVAL;
-			reg_val = &cntx->fp.d.fcsr;
-		} else if ((KVM_REG_RISCV_FP_D_REG(f[0]) <= reg_num) &&
-			   reg_num <= KVM_REG_RISCV_FP_D_REG(f[31])) {
-			if (KVM_REG_SIZE(reg->id) != sizeof(u64))
-				return -EINVAL;
-			reg_val = &cntx->fp.d.f[reg_num];
-		} else
-			return -EINVAL;
-	} else
-		return -EINVAL;
-
-	if (copy_from_user(reg_val, uaddr, KVM_REG_SIZE(reg->id)))
-		return -EFAULT;
 
 	return 0;
 }

arch/riscv/kvm/vcpu_fp.c

···
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ *     Atish Patra <[e-mail]>
+ *     Anup Patel <[e-mail]>
+ */
+
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/kvm_host.h>
+#include <linux/uaccess.h>
+
+#ifdef CONFIG_FPU
+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;
+}
+
+void kvm_riscv_vcpu_fp_clean(struct kvm_cpu_context *cntx)
+{
+	cntx->sstatus &= ~SR_FS;
+	cntx->sstatus |= SR_FS_CLEAN;
+}
+
+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);
+	}
+}
+
+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);
+	}
+}
+
+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);
+}
+
+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);
+}
+#endif
+
+int kvm_riscv_vcpu_get_reg_fp(struct kvm_vcpu *vcpu,
+			      const struct kvm_one_reg *reg,
+			      unsigned long rtype)
+{
+	struct kvm_cpu_context *cntx = &vcpu->arch.guest_context;
+	unsigned long isa = vcpu->arch.isa;
+	unsigned long __user *uaddr =
+			(unsigned long __user *)(unsigned long)reg->addr;
+	unsigned long reg_num = reg->id & ~(KVM_REG_ARCH_MASK |
+					    KVM_REG_SIZE_MASK |
+					    rtype);
+	void *reg_val;
+
+	if ((rtype == KVM_REG_RISCV_FP_F) &&
+	    riscv_isa_extension_available(&isa, f)) {
+		if (KVM_REG_SIZE(reg->id) != sizeof(u32))
+			return -EINVAL;
+		if (reg_num == KVM_REG_RISCV_FP_F_REG(fcsr))
+			reg_val = &cntx->fp.f.fcsr;
+		else if ((KVM_REG_RISCV_FP_F_REG(f[0]) <= reg_num) &&
+			  reg_num <= KVM_REG_RISCV_FP_F_REG(f[31]))
+			reg_val = &cntx->fp.f.f[reg_num];
+		else
+			return -EINVAL;
+	} else if ((rtype == KVM_REG_RISCV_FP_D) &&
+		   riscv_isa_extension_available(&isa, d)) {
+		if (reg_num == KVM_REG_RISCV_FP_D_REG(fcsr)) {
+			if (KVM_REG_SIZE(reg->id) != sizeof(u32))
+				return -EINVAL;
+			reg_val = &cntx->fp.d.fcsr;
+		} else if ((KVM_REG_RISCV_FP_D_REG(f[0]) <= reg_num) &&
+			   reg_num <= KVM_REG_RISCV_FP_D_REG(f[31])) {
+			if (KVM_REG_SIZE(reg->id) != sizeof(u64))
+				return -EINVAL;
+			reg_val = &cntx->fp.d.f[reg_num];
+		} else
+			return -EINVAL;
+	} else
+		return -EINVAL;
+
+	if (copy_to_user(uaddr, reg_val, KVM_REG_SIZE(reg->id)))
+		return -EFAULT;
+
+	return 0;
+}
+
+int kvm_riscv_vcpu_set_reg_fp(struct kvm_vcpu *vcpu,
+			      const struct kvm_one_reg *reg,
+			      unsigned long rtype)
+{
+	struct kvm_cpu_context *cntx = &vcpu->arch.guest_context;
+	unsigned long isa = vcpu->arch.isa;
+	unsigned long __user *uaddr =
+			(unsigned long __user *)(unsigned long)reg->addr;
+	unsigned long reg_num = reg->id & ~(KVM_REG_ARCH_MASK |
+					    KVM_REG_SIZE_MASK |
+					    rtype);
+	void *reg_val;
+
+	if ((rtype == KVM_REG_RISCV_FP_F) &&
+	    riscv_isa_extension_available(&isa, f)) {
+		if (KVM_REG_SIZE(reg->id) != sizeof(u32))
+			return -EINVAL;
+		if (reg_num == KVM_REG_RISCV_FP_F_REG(fcsr))
+			reg_val = &cntx->fp.f.fcsr;
+		else if ((KVM_REG_RISCV_FP_F_REG(f[0]) <= reg_num) &&
+			  reg_num <= KVM_REG_RISCV_FP_F_REG(f[31]))
+			reg_val = &cntx->fp.f.f[reg_num];
+		else
+			return -EINVAL;
+	} else if ((rtype == KVM_REG_RISCV_FP_D) &&
+		   riscv_isa_extension_available(&isa, d)) {
+		if (reg_num == KVM_REG_RISCV_FP_D_REG(fcsr)) {
+			if (KVM_REG_SIZE(reg->id) != sizeof(u32))
+				return -EINVAL;
+			reg_val = &cntx->fp.d.fcsr;
+		} else if ((KVM_REG_RISCV_FP_D_REG(f[0]) <= reg_num) &&
+			   reg_num <= KVM_REG_RISCV_FP_D_REG(f[31])) {
+			if (KVM_REG_SIZE(reg->id) != sizeof(u64))
+				return -EINVAL;
+			reg_val = &cntx->fp.d.f[reg_num];
+		} else
+			return -EINVAL;
+	} else
+		return -EINVAL;
+
+	if (copy_from_user(reg_val, uaddr, KVM_REG_SIZE(reg->id)))
+		return -EFAULT;
+
+	return 0;
+}