The isa field in config register is meant only for single letter base ISA
extensions. Multi-letter extensions can not be encoded here as it will
exceed the size of ULONG easily in future.
Only allow single letter extensions (0-25) to be encoded in that field.
Signed-off-by: Atish Patra <atishp@xxxxxxxxxxxx>
---
arch/riscv/include/uapi/asm/kvm.h | 1 +
arch/riscv/kvm/vcpu.c | 6 ++++--
2 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/arch/riscv/include/uapi/asm/kvm.h b/arch/riscv/include/uapi/asm/kvm.h
index f808ad1ce500..aa9f5a5c57d8 100644
--- a/arch/riscv/include/uapi/asm/kvm.h
+++ b/arch/riscv/include/uapi/asm/kvm.h
@@ -47,6 +47,7 @@ struct kvm_sregs {
/* CONFIG registers for KVM_GET_ONE_REG and KVM_SET_ONE_REG */
struct kvm_riscv_config {
+ /* This is a bitmap of all the single letter base ISA extensions */
unsigned long isa;
};
diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
index 624166004e36..7a07dba504f8 100644
--- a/arch/riscv/kvm/vcpu.c
+++ b/arch/riscv/kvm/vcpu.c
@@ -182,13 +182,14 @@ static int kvm_riscv_vcpu_get_reg_config(struct kvm_vcpu *vcpu,
KVM_REG_SIZE_MASK |
KVM_REG_RISCV_CONFIG);
unsigned long reg_val;
+ unsigned long isa_mask = GENMASK(25, 0);
if (KVM_REG_SIZE(reg->id) != sizeof(unsigned long))
return -EINVAL;
switch (reg_num) {
case KVM_REG_RISCV_CONFIG_REG(isa):
- reg_val = vcpu->arch.isa;
+ reg_val = vcpu->arch.isa & isa_mask;
break;
default:
return -EINVAL;
@@ -209,6 +210,7 @@ static int kvm_riscv_vcpu_set_reg_config(struct kvm_vcpu *vcpu,
KVM_REG_SIZE_MASK |
KVM_REG_RISCV_CONFIG);
unsigned long reg_val;
+ unsigned long isa_mask = GENMASK(25, 0);
if (KVM_REG_SIZE(reg->id) != sizeof(unsigned long))
return -EINVAL;
@@ -219,7 +221,7 @@ static int kvm_riscv_vcpu_set_reg_config(struct kvm_vcpu *vcpu,
switch (reg_num) {
case KVM_REG_RISCV_CONFIG_REG(isa):
if (!vcpu->arch.ran_atleast_once) {
- vcpu->arch.isa = reg_val;
+ vcpu->arch.isa = reg_val & isa_mask;
vcpu->arch.isa &= riscv_isa_extension_base(NULL);
vcpu->arch.isa &= KVM_RISCV_ISA_ALLOWED;
kvm_riscv_vcpu_fp_reset(vcpu);
--
2.30.2
