Re: [PATCH v6 2/2] i386: Add notify VM exit support

[Xiaoyao Li]

On 9/19/2022 1:46 PM, Chenyi Qiang wrote:
> > Not sure some warning would be also useful here, but I really don't know
> > the whole context so I can't tell whether there can easily be false
> > positives to pollute qemu log.
>
> The false positive case is not easy to happen unless some potential 
> issues in silicon. But in case of it, to avoid polluting qemu log, how 
> about:
>
> diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
> index ae7fb2c495..8f97133cbf 100644
> --- a/target/i386/kvm/kvm.c
> +++ b/target/i386/kvm/kvm.c
> @@ -5213,6 +5213,7 @@ int kvm_arch_handle_exit(CPUState *cs, struct 
> kvm_run *run)
>           break;
>       case KVM_EXIT_NOTIFY:
>           ret = 0;
> +        warn_report_once("KVM: notify window was exceeded in guest");
>           if (run->notify.flags & KVM_NOTIFY_CONTEXT_INVALID) {
>               warn_report("KVM: invalid context due to notify vmexit");
>               if (has_triple_fault_event) {

how about this

    case KVM_EXIT_NOTIFY:
        bool ctx_invalid = run->notify.flags & KVM_NOTIFY_CONTEXT_INVALID;
        ret = 0;
        warn_report_once("KVM: Encounter notify exit with %svalid context",
                         ctx_invalid ? "in" : "");

        if (ctx_invalid) {
            ...
        }