From: Radim Krčmář Date: Tue, 17 Mar 2015 13:02:32 +0000 (+0100) Subject: KVM: nVMX: mask unrestricted_guest if disabled on L0 X-Git-Tag: v3.19.6~6 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1b4137224d2c2a5201606d8f1acabd3d28668499;p=thirdparty%2Fkernel%2Fstable.git KVM: nVMX: mask unrestricted_guest if disabled on L0 commit 0790ec172de1bd2e23f1dbd4925426b6cc3c1b72 upstream. If EPT was enabled, unrestricted_guest was allowed in L1 regardless of L0. L1 triple faulted when running L2 guest that required emulation. Another side effect was 'WARN_ON_ONCE(vmx->nested.nested_run_pending)' in L0's dmesg: WARNING: CPU: 0 PID: 0 at arch/x86/kvm/vmx.c:9190 nested_vmx_vmexit+0x96e/0xb00 [kvm_intel] () Prevent this scenario by masking SECONDARY_EXEC_UNRESTRICTED_GUEST when the host doesn't have it enabled. Fixes: 78051e3b7e35 ("KVM: nVMX: Disable unrestricted mode if ept=0") Cc: stable@vger.kernel.org Tested-By: Kashyap Chamarthy Signed-off-by: Radim Krčmář Signed-off-by: Marcelo Tosatti Signed-off-by: Greg Kroah-Hartman --- diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index d4c58d884838d..312446418b366 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2404,8 +2404,7 @@ static __init void nested_vmx_setup_ctls_msrs(void) if (enable_ept) { /* nested EPT: emulate EPT also to L1 */ - nested_vmx_secondary_ctls_high |= SECONDARY_EXEC_ENABLE_EPT | - SECONDARY_EXEC_UNRESTRICTED_GUEST; + nested_vmx_secondary_ctls_high |= SECONDARY_EXEC_ENABLE_EPT; nested_vmx_ept_caps = VMX_EPT_PAGE_WALK_4_BIT | VMX_EPTP_WB_BIT | VMX_EPT_2MB_PAGE_BIT | VMX_EPT_INVEPT_BIT; @@ -2419,6 +2418,10 @@ static __init void nested_vmx_setup_ctls_msrs(void) } else nested_vmx_ept_caps = 0; + if (enable_unrestricted_guest) + nested_vmx_secondary_ctls_high |= + SECONDARY_EXEC_UNRESTRICTED_GUEST; + /* miscellaneous data */ rdmsr(MSR_IA32_VMX_MISC, nested_vmx_misc_low, nested_vmx_misc_high); nested_vmx_misc_low &= VMX_MISC_SAVE_EFER_LMA;