@@ -39,6 +39,7 @@
#define KVM_MAX_VCPUS VGIC_V3_MAX_CPUS
#define KVM_VCPU_MAX_FEATURES 7
+#define KVM_VCPU_VALID_FEATURES (BIT(KVM_VCPU_MAX_FEATURES) - 1)
#define KVM_REQ_SLEEP \
KVM_ARCH_REQ_FLAGS(0, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
@@ -1167,42 +1167,40 @@ int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level,
return -EINVAL;
}
-static int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
- const struct kvm_vcpu_init *init)
+static int kvm_vcpu_init_check_features(struct kvm_vcpu *vcpu,
+ const struct kvm_vcpu_init *init)
{
- unsigned int i, ret;
- u32 phys_target = kvm_target_cpu();
+ unsigned long features = init->features[0];
+ int i;
- if (init->target != phys_target)
- return -EINVAL;
+ if (features & ~KVM_VCPU_VALID_FEATURES)
+ return -ENOENT;
- /*
- * Secondary and subsequent calls to KVM_ARM_VCPU_INIT must
- * use the same target.
- */
- if (vcpu->arch.target != -1 && vcpu->arch.target != init->target)
- return -EINVAL;
+ for (i = 1; i < ARRAY_SIZE(init->features); i++) {
+ if (init->features[i])
+ return -ENOENT;
+ }
- /* -ENOENT for unknown features, -EINVAL for invalid combinations. */
- for (i = 0; i < sizeof(init->features) * 8; i++) {
- bool set = (init->features[i / 32] & (1 << (i % 32)));
+ return 0;
+}
- if (set && i >= KVM_VCPU_MAX_FEATURES)
- return -ENOENT;
+static bool kvm_vcpu_init_changed(struct kvm_vcpu *vcpu,
+ const struct kvm_vcpu_init *init)
+{
+ unsigned long features = init->features[0];
- /*
- * Secondary and subsequent calls to KVM_ARM_VCPU_INIT must
- * use the same feature set.
- */
- if (vcpu->arch.target != -1 && i < KVM_VCPU_MAX_FEATURES &&
- test_bit(i, vcpu->arch.features) != set)
- return -EINVAL;
+ return !bitmap_equal(vcpu->arch.features, &features, KVM_VCPU_MAX_FEATURES) ||
+ vcpu->arch.target != init->target;
+}
- if (set)
- set_bit(i, vcpu->arch.features);
- }
+static int __kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
+ const struct kvm_vcpu_init *init)
+{
+ unsigned long features = init->features[0];
+ int ret;
- vcpu->arch.target = phys_target;
+ vcpu->arch.target = init->target;
+ bitmap_copy(vcpu->arch.features, &features, KVM_VCPU_MAX_FEATURES);
/* Now we know what it is, we can reset it. */
ret = kvm_reset_vcpu(vcpu);
@@ -1214,6 +1212,27 @@ static int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
return ret;
}
+static int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
+ const struct kvm_vcpu_init *init)
+{
+ int ret;
+
+ if (init->target != kvm_target_cpu())
+ return -EINVAL;
+
+ ret = kvm_vcpu_init_check_features(vcpu, init);
+ if (ret)
+ return ret;
+
+ if (vcpu->arch.target == -1)
+ return __kvm_vcpu_set_target(vcpu, init);
+
+ if (kvm_vcpu_init_changed(vcpu, init))
+ return -EINVAL;
+
+ return kvm_reset_vcpu(vcpu);
+}
+
static int kvm_arch_vcpu_ioctl_vcpu_init(struct kvm_vcpu *vcpu,
struct kvm_vcpu_init *init)
{
kvm_vcpu_set_target() iteratively sanitises and copies feature flags in one go. This is rather odd, especially considering the fact that bitmap accessors can do the heavy lifting. A subsequent change will make vCPU features VM-wide, and fitting that into the present implementation is just a chore. Rework the whole thing to use bitmap accessors to sanitise and copy flags. Signed-off-by: Oliver Upton <oliver.upton@linux.dev> --- arch/arm64/include/asm/kvm_host.h | 1 + arch/arm64/kvm/arm.c | 75 +++++++++++++++++++------------ 2 files changed, 48 insertions(+), 28 deletions(-)