Modifications could get unwanted values of PLE window. (low or negative) Use ple_window and the maximal value that cannot overflow as bounds. ple_window_max defaults to a very high value, but it would make sense to set it to some fraction of the scheduler tick. Signed-off-by: Radim Krčmář <rkrcmar@xxxxxxxxxx> --- arch/x86/kvm/vmx.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 66259fd..e1192fb 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -144,6 +144,10 @@ module_param(ple_window_grow, int, S_IRUGO); static int ple_window_shrink = KVM_VMX_DEFAULT_PLE_WINDOW_SHRINK; module_param(ple_window_shrink, int, S_IRUGO); +/* Default is to compute the maximum so we can never overflow. */ +static int ple_window_max = INT_MAX / KVM_VMX_DEFAULT_PLE_WINDOW_GROW; +module_param(ple_window_max, int, S_IRUGO); + extern const ulong vmx_return; #define NR_AUTOLOAD_MSRS 8 @@ -5704,7 +5708,7 @@ static void grow_ple_window(struct kvm_vcpu *vcpu) else new = old + ple_window_grow; - vmx->ple_window = new; + vmx->ple_window = min(new, ple_window_max); } static void shrink_ple_window(struct kvm_vcpu *vcpu) @@ -5720,7 +5724,7 @@ static void shrink_ple_window(struct kvm_vcpu *vcpu) else new = old - ple_window_shrink; - vmx->ple_window = new; + vmx->ple_window = max(new, ple_window); } /* -- 2.0.4 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
