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>
---
Changes since RFC v2:
* Removed the arch vm ioctl hook in favour of
kvm_arm_vcpu_sve_config(NULL, ...).
---
arch/arm64/kvm/guest.c | 7 +++++++
virt/kvm/arm/arm.c | 3 +++
2 files changed, 10 insertions(+)
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index ffb2a25..85a112c 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -675,6 +675,9 @@ 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_sve_config_done(vcpu))
return -EBADFD; /* too late, or already configured */
@@ -769,6 +772,9 @@ 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_sve_config_done(vcpu))
return -EBADFD; /* not configured yet */
@@ -778,6 +784,7 @@ 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 */
int kvm_arm_vcpu_sve_config(struct kvm_vcpu *vcpu,
struct kvm_sve_vls __user *userp)
{
diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
index cafd701..0f92d54 100644
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c
@@ -1286,6 +1286,9 @@ long kvm_arch_vm_ioctl(struct file *filp,
return 0;
}
+ case KVM_ARM_SVE_CONFIG:
+ return kvm_arm_vcpu_sve_config(NULL, argp);
+
default:
return -EINVAL;
}
--
2.1.4
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