From: Wanpeng Li <wanpeng.li@xxxxxxxxxxx> L2 guest crash during boot if VPID is enabled on L1 and disabled on L0. This also can be catched by kvm-unit-tests/vmx.flat when VPID is disabled on L0. KVM: entry failed, hardware error 0x7 EAX=00000000 EBX=00000000 ECX=00000000 EDX=000306c3 ESI=00000000 EDI=00000000 EBP=00000000 ESP=00000000 EIP=0000fff0 EFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0 ES =0000 00000000 0000ffff 00009300 CS =f000 ffff0000 0000ffff 00009b00 SS =0000 00000000 0000ffff 00009300 DS =0000 00000000 0000ffff 00009300 FS =0000 00000000 0000ffff 00009300 GS =0000 00000000 0000ffff 00009300 LDT=0000 00000000 0000ffff 00008200 TR =0000 00000000 0000ffff 00008b00 GDT= 00000000 0000ffff IDT= 00000000 0000ffff CR0=60000010 CR2=00000000 CR3=00000000 CR4=00000000 DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000 DR6=00000000ffff0ff0 DR7=0000000000000400 EFER=0000000000000000 The enable_vpid sysfs perm parameter miss the 0 prefix, so the enable_vpid is failed to be disabled though vmcs_config bit is not set. This patch fixes it by utilizing S_IRUGO which includes 0 prefix instead. Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx> Cc: Radim Krčmář <rkrcmar@xxxxxxxxxx> Signed-off-by: Wanpeng Li <wanpeng.li@xxxxxxxxxxx> --- arch/x86/kvm/vmx.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 98e82ee..a7e4880 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -66,7 +66,7 @@ static const struct x86_cpu_id vmx_cpu_id[] = { MODULE_DEVICE_TABLE(x86cpu, vmx_cpu_id); static bool __read_mostly enable_vpid = 1; -module_param_named(vpid, enable_vpid, bool, 0444); +module_param_named(vpid, enable_vpid, bool, S_IRUGO); static bool __read_mostly flexpriority_enabled = 1; module_param_named(flexpriority, flexpriority_enabled, bool, S_IRUGO); -- 2.7.4