• Sean Christopherson's avatar
    KVM: selftests: Mark "guest_saw_irq" as volatile in xen_shinfo_test · 5addaf53
    Sean Christopherson authored
    Tag "guest_saw_irq" as "volatile" to ensure that the compiler will never
    optimize away lookups.  Relying on the compiler thinking that the flag
    is global and thus might change also works, but it's subtle, less robust,
    and looks like a bug at first glance, e.g. risks being "fixed" and
    breaking the test.
    
    Make the flag "static" as well since convincing the compiler it's global
    is no longer necessary.
    
    Alternatively, the flag could be accessed with {READ,WRITE}_ONCE(), but
    literally every access would need the wrappers, and eking out performance
    isn't exactly top priority for selftests.
    Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
    Message-Id: <20221013211234.1318131-17-seanjc@google.com>
    Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
    5addaf53
xen_shinfo_test.c 26.9 KB