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@xxxxxxx>
---
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)
--
2.1.4
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