On 09/06/2018 01:15 AM, Eric Blake wrote:
Adding Markus, as the maintainer of Error APIs, to make sure he sees
this thread.
Thanks. :)
On 09/04/2018 06:22 AM, Daniel P. Berrangé wrote:
On Tue, Sep 04, 2018 at 07:08:20PM +0800, Fei Li wrote:
In the subject line: s/paramater/parameter/
Thanks for pointing this out! :)
The caller of qemu_init_vcpu() already passed the **errp to handle
errors. In view of this, add a new Error parameter to the following
call trace to propagate the error and let the final caller check it.
Signed-off-by: Fei Li <f...@suse.com>
---
-void qemu_init_vcpu(CPUState *cpu)
+void qemu_init_vcpu(CPUState *cpu, Error **errp)
{
cpu->nr_cores = smp_cores;
cpu->nr_threads = smp_threads;
cpu->stopped = true;
+ Error *local_err = NULL;
if (!cpu->as) {
/* If the target cpu hasn't set up any address spaces itself,
@@ -2046,17 +2047,22 @@ void qemu_init_vcpu(CPUState *cpu)
}
if (kvm_enabled()) {
- qemu_kvm_start_vcpu(cpu);
+ qemu_kvm_start_vcpu(cpu, &local_err);
} else if (hax_enabled()) {
- qemu_hax_start_vcpu(cpu);
+ qemu_hax_start_vcpu(cpu, &local_err);
} else if (hvf_enabled()) {
- qemu_hvf_start_vcpu(cpu);
+ qemu_hvf_start_vcpu(cpu, &local_err);
} else if (tcg_enabled()) {
- qemu_tcg_init_vcpu(cpu);
+ qemu_tcg_init_vcpu(cpu, &local_err);
} else if (whpx_enabled()) {
- qemu_whpx_start_vcpu(cpu);
+ qemu_whpx_start_vcpu(cpu, &local_err);
} else {
- qemu_dummy_start_vcpu(cpu);
+ qemu_dummy_start_vcpu(cpu, &local_err);
+ }
+
+ if (local_err) {
+ error_propagate(errp, local_err);
+ return;
}
I'd be inclined to make this method return a boolean, so....
diff --git a/target/alpha/cpu.c b/target/alpha/cpu.c
index b08078e7fc..5b0b4892f2 100644
--- a/target/alpha/cpu.c
+++ b/target/alpha/cpu.c
@@ -66,7 +66,11 @@ static void alpha_cpu_realizefn(DeviceState *dev,
Error **errp)
return;
}
- qemu_init_vcpu(cs);
+ qemu_init_vcpu(cs, &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ return;
+ }
...this can be simplified to get rid of the local error object
if (!qemu_init_vcpu(cs, errp)) {
return;
}
Returning a bool introduces an interesting semantic question on
whether 0 is success or failure (-1/0 vs. false/true means you have to
pay attention to return type to decide between !func() or func()<0
when using the return value to learn if errp was set). But Markus has
expressed some thoughts on the matter before:
https://lists.gnu.org/archive/html/qemu-devel/2017-08/msg00124.html
and favored a bool return if only for consistency with glib and to
avoid abuse of trying to overload the returned int when using errp is
better.
Thanks for providing these instructive discussions, I read the link, and
yes,
I agree with "return a bool: false/true inside the callee". Just as the
following:
if (!foo(arg, errp)) { // assuming foo() returns a bool: false/true
handle the error...
}
As this is "Nicely concise." :)
I will prepare the next version according to all the comments.
Have a nice day, thanks all
Fei
