On Tue, Apr 19, 2022 at 6:33 PM Atish Patra <atishp@xxxxxxxxxxxx> wrote:
>
> Currently, the config reg register allows to disable all allowed
> single letter ISA extensions. It shouldn't be the case as vmm
> shouldn't be able disable base extensions (imac).
/s/able/able to/
> These extensions should always be enabled as long as they are enabled
> in the host ISA.
>
> Signed-off-by: Atish Patra <atishp@xxxxxxxxxxxx>
> ---
> arch/riscv/kvm/vcpu.c | 21 +++++++++++++--------
> 1 file changed, 13 insertions(+), 8 deletions(-)
>
> diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
> index 2e25a7b83a1b..14dd801651e5 100644
> --- a/arch/riscv/kvm/vcpu.c
> +++ b/arch/riscv/kvm/vcpu.c
> @@ -38,12 +38,16 @@ const struct kvm_stats_header kvm_vcpu_stats_header = {
> sizeof(kvm_vcpu_stats_desc),
> };
>
> -#define KVM_RISCV_ISA_ALLOWED (riscv_isa_extension_mask(a) | \
> - riscv_isa_extension_mask(c) | \
> - riscv_isa_extension_mask(d) | \
> - riscv_isa_extension_mask(f) | \
> - riscv_isa_extension_mask(i) | \
> - riscv_isa_extension_mask(m))
> +#define KVM_RISCV_ISA_DISABLE_ALLOWED (riscv_isa_extension_mask(d) | \
> + riscv_isa_extension_mask(f))
> +
> +#define KVM_RISCV_ISA_DISABLE_NOT_ALLOWED (riscv_isa_extension_mask(a) | \
> + riscv_isa_extension_mask(c) | \
> + riscv_isa_extension_mask(i) | \
> + riscv_isa_extension_mask(m))
> +
> +#define KVM_RISCV_ISA_ALLOWED (KVM_RISCV_ISA_DISABLE_ALLOWED | \
> + KVM_RISCV_ISA_DISABLE_NOT_ALLOWED)
>
> static void kvm_riscv_reset_vcpu(struct kvm_vcpu *vcpu)
> {
> @@ -217,9 +221,10 @@ 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;
> + /* Ignore the disable request for these extensions */
> + vcpu->arch.isa = reg_val | KVM_RISCV_ISA_DISABLE_NOT_ALLOWED;
> vcpu->arch.isa &= riscv_isa_extension_base(NULL);
> - vcpu->arch.isa &= KVM_RISCV_ISA_ALLOWED;
> + vcpu->arch.isa &= KVM_RISCV_ISA_DISABLE_ALLOWED;
> kvm_riscv_vcpu_fp_reset(vcpu);
> } else {
> return -EOPNOTSUPP;
> --
> 2.25.1
>
Sorry. I forgot to add the fixes tag.
Fixes: 92ad82002c39 (RISC-V: KVM: Implement
KVM_GET_ONE_REG/KVM_SET_ONE_REG ioctls)
--
Regards,
Atish
