This series fixes few issues around ISA string generations for guests.
Earlier these patches were part of the sstc series[1] but I created
a separate series for these fixes as they can be applied separately
as a part of rc fixes.
[1] https://lore.kernel.org/lkml/[email protected]/
Atish Patra (2):
RISC-V: KVM: Remove 's' & 'u' as valid ISA extension
RISC-V: KVM: Restrict the extensions that can be disabled
arch/riscv/kvm/vcpu.c | 23 +++++++++++++----------
1 file changed, 13 insertions(+), 10 deletions(-)
--
2.25.1
There are no ISA extension defined as 's' & 'u' in RISC-V specifications.
The misa register defines 's' & 'u' bit as Supervisor/User privilege mode
enabled. But it should not appear in the ISA extension in the device tree.
Remove those from the allowed ISA extension for kvm.
Signed-off-by: Atish Patra <[email protected]>
---
arch/riscv/kvm/vcpu.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
index 6785aef4cbd4..2e25a7b83a1b 100644
--- a/arch/riscv/kvm/vcpu.c
+++ b/arch/riscv/kvm/vcpu.c
@@ -43,9 +43,7 @@ const struct kvm_stats_header kvm_vcpu_stats_header = {
riscv_isa_extension_mask(d) | \
riscv_isa_extension_mask(f) | \
riscv_isa_extension_mask(i) | \
- riscv_isa_extension_mask(m) | \
- riscv_isa_extension_mask(s) | \
- riscv_isa_extension_mask(u))
+ riscv_isa_extension_mask(m))
static void kvm_riscv_reset_vcpu(struct kvm_vcpu *vcpu)
{
--
2.25.1
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 <[email protected]>
---
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
On Tue, Apr 19, 2022 at 6:33 PM Atish Patra <[email protected]> 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 <[email protected]>
> ---
> 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