KVM: VMX: make PLE window per-VCPU
Change PLE window into per-VCPU variable, seeded from module parameter,
to allow greater flexibility.
Brings in a small overhead on every vmentry.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 7c26533..7017599 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -484,6 +484,10 @@
/* Support for a guest hypervisor (nested VMX) */
struct nested_vmx nested;
+
+ /* Dynamic PLE window. */
+ int ple_window;
+ bool ple_window_dirty;
};
enum segment_cache_field {
@@ -4402,7 +4406,8 @@
if (ple_gap) {
vmcs_write32(PLE_GAP, ple_gap);
- vmcs_write32(PLE_WINDOW, ple_window);
+ vmx->ple_window = ple_window;
+ vmx->ple_window_dirty = true;
}
vmcs_write32(PAGE_FAULT_ERROR_CODE_MASK, 0);
@@ -7389,6 +7394,11 @@
if (vmx->emulation_required)
return;
+ if (vmx->ple_window_dirty) {
+ vmx->ple_window_dirty = false;
+ vmcs_write32(PLE_WINDOW, vmx->ple_window);
+ }
+
if (vmx->nested.sync_shadow_vmcs) {
copy_vmcs12_to_shadow(vmx);
vmx->nested.sync_shadow_vmcs = false;