[PATCH v4 09/10] RISC-V: KVM: Improve vector save/restore errors

Daniel Henrique Barboza
2023-08-03T16:33:41Z

From: Andrew Jones <ajones@ventanamicro.com>

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>
---
arch/riscv/kvm/vcpu_vector.c | 60 ++++++++++++++++++++----------------
1 file changed, 33 insertions(+), 27 deletions(-)

diff --git a/arch/riscv/kvm/vcpu_vector.c b/arch/riscv/kvm/vcpu_vector.c
index edd2eecbddc2..39c5bceb4d1b 100644
--- 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;