[PATCH v2] KVM: VMX: Don't expose PLE enable if there is no hardware support

From: Wanpeng Li
Date: Thu Sep 28 2017 - 21:06:35 EST


From: Wanpeng Li <wanpeng.li@xxxxxxxxxxx>

PLE_Window: Software can configure this field as an upper bound on the amount of time
a guest is allowed to execute in a PAUSE LOOP.

KVM doesn't expose the PLE capability to the L1 hypervisor, however, ple_window still
shows the default value on L1 hypervisor. This patch fixes it by clearing all the
PLE related module parameter if there is no PLE capability.

Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Radim KrÄmÃÅ <rkrcmar@xxxxxxxxxx>
Signed-off-by: Wanpeng Li <wanpeng.li@xxxxxxxxxxx>
---
v1 -> v2:
* fix typo in patch description

arch/x86/kvm/vmx.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index c83d28b..4d4f9b4 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -6781,8 +6781,13 @@ static __init int hardware_setup(void)
if (enable_ept && !cpu_has_vmx_ept_2m_page())
kvm_disable_largepages();

- if (!cpu_has_vmx_ple())
+ if (!cpu_has_vmx_ple()) {
ple_gap = 0;
+ ple_window = 0;
+ ple_window_grow = 0;
+ ple_window_max = 0;
+ ple_window_shrink = 0;
+ }

if (!cpu_has_vmx_apicv()) {
enable_apicv = 0;
--
2.7.4