On Tue, 17 Oct 2023, Raghavendra Rao Ananta wrote:
On Tue, Oct 17, 2023 at 8:52 AM Sebastian Ott <sebott@xxxxxxxxxx> wrote:
On Mon, 9 Oct 2023, Raghavendra Rao Ananta wrote:
+static int set_pmcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r,
+ u64 val)
+{
+ struct kvm *kvm = vcpu->kvm;
+ u64 new_n, mutable_mask;
+
+ mutex_lock(&kvm->arch.config_lock);
+
+ /*
+ * Make PMCR immutable once the VM has started running, but do
+ * not return an error (-EBUSY) to meet the existing expectations.
+ */
Why should we mention which error we're _not_ returning?
Oh, it's not to break the existing userspace expectations. Before this
series, any 'write' from userspace was possible. Returning -EBUSY all
of a sudden might tamper with this expectation.
Yes I get that part. What I've meant is why specifically mention -EBUSY?
You're also not returning -EFAULT nor -EINVAL.
/*
* Make PMCR immutable once the VM has started running, but do
* not return an error to meet the existing expectations.
*/
IMHO provides the same info to the reader and is less confusing
Sebastian
