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-rw-r--r--arch/riscv/kvm/vcpu_fp.c167
1 files changed, 167 insertions, 0 deletions
diff --git a/arch/riscv/kvm/vcpu_fp.c b/arch/riscv/kvm/vcpu_fp.c
new file mode 100644
index 000000000000..1b070152578f
--- /dev/null
+++ b/arch/riscv/kvm/vcpu_fp.c
@@ -0,0 +1,167 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ * Atish Patra <atish.patra@wdc.com>
+ * Anup Patel <anup.patel@wdc.com>
+ */
+
+#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;
+}