On 2/28/20 1:40 PM, Jim Mattson wrote: > On Fri, Feb 28, 2020 at 12:59 AM Oliver Upton <oupton@xxxxxxxxxx> wrote: >> >> Switch the default value of the 'avic' module parameter to 1. >> >> Suggested-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> >> Signed-off-by: Oliver Upton <oupton@xxxxxxxxxx> >> --- >> arch/x86/kvm/svm.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c >> index b82a500bccb7..70d2df13eb02 100644 >> --- a/arch/x86/kvm/svm.c >> +++ b/arch/x86/kvm/svm.c >> @@ -358,7 +358,7 @@ static int nested = true; >> module_param(nested, int, S_IRUGO); >> >> /* enable / disable AVIC */ >> -static int avic; >> +static int avic = 1; >> #ifdef CONFIG_X86_LOCAL_APIC >> module_param(avic, int, S_IRUGO); >> #endif >> -- >> 2.25.1.481.gfbce0eb801-goog > > How extensively has this been tested? Why hasn't someone from AMD > suggested this change? I personally don't suggest enable AVIC by default. There are cases of slow AVIC doorbell delivery, due to delivery path and contention under a large number of guest cores. >
