| Message ID | 1550519559-15915-18-git-send-email-Dave.Martin@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: arm64: SVE guest support | expand |
On 18/02/2019 19:52, Dave Martin wrote: > In order to avoid the pointless complexity of maintaining two ioctl > register access views of the same data, this patch blocks ioctl > access to the FPSIMD V-registers on vcpus that support SVE. > > This will make it more straightforward to add SVE register access > support. > > Since SVE is an opt-in feature for userspace, this will not affect > existing users. > > Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Julien Thierry <julien.thierry@arm.com> > --- > arch/arm64/kvm/guest.c | 38 +++++++++++++++++++++++++++----------- > 1 file changed, 27 insertions(+), 11 deletions(-) > > diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c > index f83fe22..f491456 100644 > --- a/arch/arm64/kvm/guest.c > +++ b/arch/arm64/kvm/guest.c > @@ -95,7 +95,14 @@ static int core_reg_size_from_offset(u64 off) > return -EINVAL; > } > > -static int validate_core_offset(const struct kvm_one_reg *reg) > +static bool core_reg_offset_is_vreg(u64 off) > +{ > + return off >= KVM_REG_ARM_CORE_REG(fp_regs.vregs) && > + off < KVM_REG_ARM_CORE_REG(fp_regs.fpsr); > +} > + > +static int validate_core_offset(const struct kvm_vcpu *vcpu, > + const struct kvm_one_reg *reg) > { > u64 off = core_reg_offset_from_id(reg->id); > int size = core_reg_size_from_offset(off); > @@ -103,10 +110,18 @@ static int validate_core_offset(const struct kvm_one_reg *reg) > if (size < 0) > return -EINVAL; > > - if (KVM_REG_SIZE(reg->id) == size) > - return 0; > + if (KVM_REG_SIZE(reg->id) != size) > + return -EINVAL; > > - return -EINVAL; > + /* > + * The KVM_REG_ARM64_SVE regs must be used instead of > + * KVM_REG_ARM_CORE for accessing the FPSIMD V-registers on > + * SVE-enabled vcpus: > + */ > + if (vcpu_has_sve(vcpu) && core_reg_offset_is_vreg(off)) > + return -EINVAL; > + > + return 0; > } > > static int get_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) > @@ -128,7 +143,7 @@ static int get_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) > (off + (KVM_REG_SIZE(reg->id) / sizeof(__u32))) >= nr_regs) > return -ENOENT; > > - if (validate_core_offset(reg)) > + if (validate_core_offset(vcpu, reg)) > return -EINVAL; > > if (copy_to_user(uaddr, ((u32 *)regs) + off, KVM_REG_SIZE(reg->id))) > @@ -153,7 +168,7 @@ static int set_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) > (off + (KVM_REG_SIZE(reg->id) / sizeof(__u32))) >= nr_regs) > return -ENOENT; > > - if (validate_core_offset(reg)) > + if (validate_core_offset(vcpu, reg)) > return -EINVAL; > > if (KVM_REG_SIZE(reg->id) > sizeof(tmp)) > @@ -206,7 +221,8 @@ int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs) > return -EINVAL; > } > > -static int copy_core_reg_indices(u64 __user **uind) > +static int copy_core_reg_indices(const struct kvm_vcpu *vcpu, > + u64 __user **uind) > { > unsigned int i; > int n = 0; > @@ -248,9 +264,9 @@ static int copy_core_reg_indices(u64 __user **uind) > return n; > } > > -static unsigned long num_core_regs(void) > +static unsigned long num_core_regs(const struct kvm_vcpu *vcpu) > { > - return copy_core_reg_indices(NULL); > + return copy_core_reg_indices(vcpu, NULL); > } > > /** > @@ -315,7 +331,7 @@ unsigned long kvm_arm_num_regs(struct kvm_vcpu *vcpu) > { > unsigned long res = 0; > > - res += num_core_regs(); > + res += num_core_regs(vcpu); > res += kvm_arm_num_sys_reg_descs(vcpu); > res += kvm_arm_get_fw_num_regs(vcpu); > res += NUM_TIMER_REGS; > @@ -332,7 +348,7 @@ int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices) > { > int ret; > > - ret = copy_core_reg_indices(&uindices); > + ret = copy_core_reg_indices(vcpu, &uindices); > if (ret < 0) > return ret; > >
On Thu, Feb 21, 2019 at 12:06:23PM +0000, Julien Thierry wrote: > > > On 18/02/2019 19:52, Dave Martin wrote: > > In order to avoid the pointless complexity of maintaining two ioctl > > register access views of the same data, this patch blocks ioctl > > access to the FPSIMD V-registers on vcpus that support SVE. > > > > This will make it more straightforward to add SVE register access > > support. > > > > Since SVE is an opt-in feature for userspace, this will not affect > > existing users. > > > > Signed-off-by: Dave Martin <Dave.Martin@arm.com> > > Reviewed-by: Julien Thierry <julien.thierry@arm.com> Thanks ---Dave
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c index f83fe22..f491456 100644 --- a/arch/arm64/kvm/guest.c +++ b/arch/arm64/kvm/guest.c @@ -95,7 +95,14 @@ static int core_reg_size_from_offset(u64 off) return -EINVAL; } -static int validate_core_offset(const struct kvm_one_reg *reg) +static bool core_reg_offset_is_vreg(u64 off) +{ + return off >= KVM_REG_ARM_CORE_REG(fp_regs.vregs) && + off < KVM_REG_ARM_CORE_REG(fp_regs.fpsr); +} + +static int validate_core_offset(const struct kvm_vcpu *vcpu, + const struct kvm_one_reg *reg) { u64 off = core_reg_offset_from_id(reg->id); int size = core_reg_size_from_offset(off); @@ -103,10 +110,18 @@ static int validate_core_offset(const struct kvm_one_reg *reg) if (size < 0) return -EINVAL; - if (KVM_REG_SIZE(reg->id) == size) - return 0; + if (KVM_REG_SIZE(reg->id) != size) + return -EINVAL; - return -EINVAL; + /* + * The KVM_REG_ARM64_SVE regs must be used instead of + * KVM_REG_ARM_CORE for accessing the FPSIMD V-registers on + * SVE-enabled vcpus: + */ + if (vcpu_has_sve(vcpu) && core_reg_offset_is_vreg(off)) + return -EINVAL; + + return 0; } static int get_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) @@ -128,7 +143,7 @@ static int get_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) (off + (KVM_REG_SIZE(reg->id) / sizeof(__u32))) >= nr_regs) return -ENOENT; - if (validate_core_offset(reg)) + if (validate_core_offset(vcpu, reg)) return -EINVAL; if (copy_to_user(uaddr, ((u32 *)regs) + off, KVM_REG_SIZE(reg->id))) @@ -153,7 +168,7 @@ static int set_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) (off + (KVM_REG_SIZE(reg->id) / sizeof(__u32))) >= nr_regs) return -ENOENT; - if (validate_core_offset(reg)) + if (validate_core_offset(vcpu, reg)) return -EINVAL; if (KVM_REG_SIZE(reg->id) > sizeof(tmp)) @@ -206,7 +221,8 @@ int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs) return -EINVAL; } -static int copy_core_reg_indices(u64 __user **uind) +static int copy_core_reg_indices(const struct kvm_vcpu *vcpu, + u64 __user **uind) { unsigned int i; int n = 0; @@ -248,9 +264,9 @@ static int copy_core_reg_indices(u64 __user **uind) return n; } -static unsigned long num_core_regs(void) +static unsigned long num_core_regs(const struct kvm_vcpu *vcpu) { - return copy_core_reg_indices(NULL); + return copy_core_reg_indices(vcpu, NULL); } /** @@ -315,7 +331,7 @@ unsigned long kvm_arm_num_regs(struct kvm_vcpu *vcpu) { unsigned long res = 0; - res += num_core_regs(); + res += num_core_regs(vcpu); res += kvm_arm_num_sys_reg_descs(vcpu); res += kvm_arm_get_fw_num_regs(vcpu); res += NUM_TIMER_REGS; @@ -332,7 +348,7 @@ int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices) { int ret; - ret = copy_core_reg_indices(&uindices); + ret = copy_core_reg_indices(vcpu, &uindices); if (ret < 0) return ret;
In order to avoid the pointless complexity of maintaining two ioctl register access views of the same data, this patch blocks ioctl access to the FPSIMD V-registers on vcpus that support SVE. This will make it more straightforward to add SVE register access support. Since SVE is an opt-in feature for userspace, this will not affect existing users. Signed-off-by: Dave Martin <Dave.Martin@arm.com> --- arch/arm64/kvm/guest.c | 38 +++++++++++++++++++++++++++----------- 1 file changed, 27 insertions(+), 11 deletions(-)