diff mbox series

[2/2] RISC-V: KVM: Restrict the extensions that can be disabled

Message ID 20220420013258.3639264-3-atishp@rivosinc.com (mailing list archive)
State New, archived
Headers show
Series Miscellenous ISA string fixup | expand

Commit Message

Atish Kumar Patra April 20, 2022, 1:32 a.m. UTC
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).
These extensions should always be enabled as long as they are enabled
in the host ISA.

Signed-off-by: Atish Patra <atishp@rivosinc.com>
---
 arch/riscv/kvm/vcpu.c | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

Comments

Atish Patra April 20, 2022, 7:42 a.m. UTC | #1
On Tue, Apr 19, 2022 at 6:33 PM Atish Patra <atishp@rivosinc.com> 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@rivosinc.com>
> ---
>  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)
Anup Patel April 20, 2022, 8:47 a.m. UTC | #2
On Wed, Apr 20, 2022 at 1:13 PM Atish Patra <atishp@atishpatra.org> wrote:
>
> On Tue, Apr 19, 2022 at 6:33 PM Atish Patra <atishp@rivosinc.com> 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@rivosinc.com>
> > ---
> >  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)

I have queued this for fixes.

Thanks,
Anup

>
> --
> Regards,
> Atish
>
> --
> kvm-riscv mailing list
> kvm-riscv@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/kvm-riscv
diff mbox series

Patch

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;