RISC-V: KVM: Improve vector save/restore errors

kvm_riscv_vcpu_(get/set)_reg_vector() now returns ENOENT if V is not
available, EINVAL if reg type is not of VECTOR type, and any error that
might be thrown by kvm_riscv_vcpu_vreg_addr().

Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>

diff --git a/arch/riscv/kvm/vcpu_vector.c b/arch/riscv/kvm/vcpu_vector.c
index edd2eecbddc2ed14666e330590272dccd52ab54a..39c5bceb4d1b022258da4a2e7193b88ee69bef8c 100644 (file)
--- a/arch/riscv/kvm/vcpu_vector.c
+++ b/arch/riscv/kvm/vcpu_vector.c
@@ -91,44 +91,44 @@ void kvm_riscv_vcpu_free_vector_context(struct kvm_vcpu *vcpu)
 }
 #endif
 
-static void *kvm_riscv_vcpu_vreg_addr(struct kvm_vcpu *vcpu,
+static int kvm_riscv_vcpu_vreg_addr(struct kvm_vcpu *vcpu,
                                      unsigned long reg_num,
-                                     size_t reg_size)
+                                     size_t reg_size,
+                                     void **reg_val)
 {
        struct kvm_cpu_context *cntx = &vcpu->arch.guest_context;
-       void *reg_val;
        size_t vlenb = riscv_v_vsize / 32;
 
        if (reg_num < KVM_REG_RISCV_VECTOR_REG(0)) {
                if (reg_size != sizeof(unsigned long))
-                       return NULL;
+                       return -EINVAL;
                switch (reg_num) {
                case KVM_REG_RISCV_VECTOR_CSR_REG(vstart):
-                       reg_val = &cntx->vector.vstart;
+                       *reg_val = &cntx->vector.vstart;
                        break;
                case KVM_REG_RISCV_VECTOR_CSR_REG(vl):
-                       reg_val = &cntx->vector.vl;
+                       *reg_val = &cntx->vector.vl;
                        break;
                case KVM_REG_RISCV_VECTOR_CSR_REG(vtype):
-                       reg_val = &cntx->vector.vtype;
+                       *reg_val = &cntx->vector.vtype;
                        break;
                case KVM_REG_RISCV_VECTOR_CSR_REG(vcsr):
-                       reg_val = &cntx->vector.vcsr;
+                       *reg_val = &cntx->vector.vcsr;
                        break;
                case KVM_REG_RISCV_VECTOR_CSR_REG(datap):
                default:
-                       return NULL;
+                       return -ENOENT;
                }
        } else if (reg_num <= KVM_REG_RISCV_VECTOR_REG(31)) {
                if (reg_size != vlenb)
-                       return NULL;
-               reg_val = cntx->vector.datap
+                       return -EINVAL;
+               *reg_val = cntx->vector.datap
                          + (reg_num - KVM_REG_RISCV_VECTOR_REG(0)) * vlenb;
        } else {
-               return NULL;
+               return -ENOENT;
        }
 
-       return reg_val;
+       return 0;
 }
 
 int kvm_riscv_vcpu_get_reg_vector(struct kvm_vcpu *vcpu,
@@ -141,17 +141,20 @@ int kvm_riscv_vcpu_get_reg_vector(struct kvm_vcpu *vcpu,
        unsigned long reg_num = reg->id & ~(KVM_REG_ARCH_MASK |
                                            KVM_REG_SIZE_MASK |
                                            rtype);
-       void *reg_val = NULL;
        size_t reg_size = KVM_REG_SIZE(reg->id);
+       void *reg_val;
+       int rc;
 
-       if (rtype == KVM_REG_RISCV_VECTOR &&
-           riscv_isa_extension_available(isa, v)) {
-               reg_val = kvm_riscv_vcpu_vreg_addr(vcpu, reg_num, reg_size);
-       }
-
-       if (!reg_val)
+       if (rtype != KVM_REG_RISCV_VECTOR)
                return -EINVAL;
 
+       if (!riscv_isa_extension_available(isa, v))
+               return -ENOENT;
+
+       rc = kvm_riscv_vcpu_vreg_addr(vcpu, reg_num, reg_size, &reg_val);
+       if (rc)
+               return rc;
+
        if (copy_to_user(uaddr, reg_val, reg_size))
                return -EFAULT;
 
@@ -168,17 +171,20 @@ int kvm_riscv_vcpu_set_reg_vector(struct kvm_vcpu *vcpu,
        unsigned long reg_num = reg->id & ~(KVM_REG_ARCH_MASK |
                                            KVM_REG_SIZE_MASK |
                                            rtype);
-       void *reg_val = NULL;
        size_t reg_size = KVM_REG_SIZE(reg->id);
+       void *reg_val;
+       int rc;
 
-       if (rtype == KVM_REG_RISCV_VECTOR &&
-           riscv_isa_extension_available(isa, v)) {
-               reg_val = kvm_riscv_vcpu_vreg_addr(vcpu, reg_num, reg_size);
-       }
-
-       if (!reg_val)
+       if (rtype != KVM_REG_RISCV_VECTOR)
                return -EINVAL;
 
+       if (!riscv_isa_extension_available(isa, v))
+               return -ENOENT;
+
+       rc = kvm_riscv_vcpu_vreg_addr(vcpu, reg_num, reg_size, &reg_val);
+       if (rc)
+               return rc;
+
        if (copy_from_user(reg_val, uaddr, reg_size))
                return -EFAULT;