| Message ID | 1538141967-15375-22-git-send-email-Dave.Martin@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: arm64: Initial support for SVE guests | expand |
Dave Martin <Dave.Martin@arm.com> writes: > Since userspace may need to decide on the set of vector lengths for > the guest before setting up a vm, it is onerous to require a vcpu > fd to be available first. KVM_ARM_SVE_CONFIG_QUERY is not > vcpu-dependent anyway, so this patch wires up KVM_ARM_SVE_CONFIG to > be usable on a vm fd where appropriate. > > Subcommands that are vcpu-dependent (currently > KVM_ARM_SVE_CONFIG_SET, KVM_ARM_SVE_CONFIG_GET) will return -EINVAL > if invoked on a vm fd. > > Signed-off-by: Dave Martin <Dave.Martin@arm.com> Apropos comments on last patch, this could go away if we went with just reporting the max VL via the SVE capability probe which works on the vmfd. > --- > arch/arm64/kvm/guest.c | 17 ++++++++++++++++- > 1 file changed, 16 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c > index f066b17..2313c22 100644 > --- a/arch/arm64/kvm/guest.c > +++ b/arch/arm64/kvm/guest.c > @@ -574,6 +574,9 @@ static int kvm_vcpu_set_sve_vls(struct kvm_vcpu *vcpu, struct kvm_sve_vls *vls, > unsigned int vq, max_vq; > int ret; > > + if (!vcpu) > + return -EINVAL; /* per-vcpu operation on vm fd */ > + > if (vcpu->arch.has_run_once || vcpu_has_sve(vcpu)) > return -EBADFD; /* too late, or already configured */ > > @@ -659,6 +662,9 @@ static int kvm_vcpu_query_sve_vls(struct kvm_vcpu *vcpu, struct kvm_sve_vls *vls > static int kvm_vcpu_get_sve_vls(struct kvm_vcpu *vcpu, struct kvm_sve_vls *vls, > struct kvm_sve_vls __user *userp) > { > + if (!vcpu) > + return -EINVAL; /* per-vcpu operation on vm fd */ > + > if (!vcpu_has_sve(vcpu)) > return -EBADFD; /* not configured yet */ > > @@ -668,6 +674,7 @@ static int kvm_vcpu_get_sve_vls(struct kvm_vcpu *vcpu, struct kvm_sve_vls *vls, > sve_vq_from_vl(vcpu->arch.sve_max_vl), userp); > } > > +/* vcpu may be NULL if this is called via a vm fd */ > static int kvm_vcpu_sve_config(struct kvm_vcpu *vcpu, > struct kvm_sve_vls __user *userp) > { > @@ -717,7 +724,15 @@ int kvm_arm_arch_vcpu_ioctl(struct kvm_vcpu *vcpu, > int kvm_arm_arch_vm_ioctl(struct kvm *kvm, > unsigned int ioctl, unsigned long arg) > { > - return -EINVAL; > + void __user *userp = (void __user *)arg; > + > + switch (ioctl) { > + case KVM_ARM_SVE_CONFIG: > + return kvm_vcpu_sve_config(NULL, userp); > + > + default: > + return -EINVAL; > + } > } > > int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu) -- Alex Bennée
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c index f066b17..2313c22 100644 --- a/arch/arm64/kvm/guest.c +++ b/arch/arm64/kvm/guest.c @@ -574,6 +574,9 @@ static int kvm_vcpu_set_sve_vls(struct kvm_vcpu *vcpu, struct kvm_sve_vls *vls, unsigned int vq, max_vq; int ret; + if (!vcpu) + return -EINVAL; /* per-vcpu operation on vm fd */ + if (vcpu->arch.has_run_once || vcpu_has_sve(vcpu)) return -EBADFD; /* too late, or already configured */ @@ -659,6 +662,9 @@ static int kvm_vcpu_query_sve_vls(struct kvm_vcpu *vcpu, struct kvm_sve_vls *vls static int kvm_vcpu_get_sve_vls(struct kvm_vcpu *vcpu, struct kvm_sve_vls *vls, struct kvm_sve_vls __user *userp) { + if (!vcpu) + return -EINVAL; /* per-vcpu operation on vm fd */ + if (!vcpu_has_sve(vcpu)) return -EBADFD; /* not configured yet */ @@ -668,6 +674,7 @@ static int kvm_vcpu_get_sve_vls(struct kvm_vcpu *vcpu, struct kvm_sve_vls *vls, sve_vq_from_vl(vcpu->arch.sve_max_vl), userp); } +/* vcpu may be NULL if this is called via a vm fd */ static int kvm_vcpu_sve_config(struct kvm_vcpu *vcpu, struct kvm_sve_vls __user *userp) { @@ -717,7 +724,15 @@ int kvm_arm_arch_vcpu_ioctl(struct kvm_vcpu *vcpu, int kvm_arm_arch_vm_ioctl(struct kvm *kvm, unsigned int ioctl, unsigned long arg) { - return -EINVAL; + void __user *userp = (void __user *)arg; + + switch (ioctl) { + case KVM_ARM_SVE_CONFIG: + return kvm_vcpu_sve_config(NULL, userp); + + default: + return -EINVAL; + } } int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
Since userspace may need to decide on the set of vector lengths for the guest before setting up a vm, it is onerous to require a vcpu fd to be available first. KVM_ARM_SVE_CONFIG_QUERY is not vcpu-dependent anyway, so this patch wires up KVM_ARM_SVE_CONFIG to be usable on a vm fd where appropriate. Subcommands that are vcpu-dependent (currently KVM_ARM_SVE_CONFIG_SET, KVM_ARM_SVE_CONFIG_GET) will return -EINVAL if invoked on a vm fd. Signed-off-by: Dave Martin <Dave.Martin@arm.com> --- arch/arm64/kvm/guest.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-)