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 <rkrc...@redhat.com>
---
I've been thinking about a general hierarchical per-vcpu variable model,
but it's hard to have current performance and sane code.
arch/x86/kvm/vmx.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 2b306f9..eaa5574 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -484,6 +484,9 @@ struct vcpu_vmx {
/* Support for a guest hypervisor (nested VMX) */
struct nested_vmx nested;
+
+ /* Dynamic PLE window. */
+ int ple_window;
};
enum segment_cache_field {
@@ -4403,6 +4406,7 @@ static int vmx_vcpu_setup(struct vcpu_vmx *vmx)
if (ple_gap) {
vmcs_write32(PLE_GAP, ple_gap);
vmcs_write32(PLE_WINDOW, ple_window);
+ vmx->ple_window = ple_window;
}
vmcs_write32(PAGE_FAULT_ERROR_CODE_MASK, 0);
@@ -7387,6 +7391,9 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
if (vmx->emulation_required)
return;
+ if (ple_gap)
+ vmcs_write32(PLE_WINDOW, vmx->ple_window);
+
if (vmx->nested.sync_shadow_vmcs) {
copy_vmcs12_to_shadow(vmx);
vmx->nested.sync_shadow_vmcs = false;
--
2.0.4
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