From 66c1d22bc170f9bfaa54a11e34ac7f0392e52100 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= Date: Tue, 17 Mar 2015 14:02:32 +0100 Subject: [PATCH] KVM: nVMX: mask unrestricted_guest if disabled on L0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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") Tested-By: Kashyap Chamarthy Signed-off-by: Radim Krčmář Signed-off-by: Marcelo Tosatti [ luis: backported to 3.16: - use nested_vmx_secondary_ctls_high instead of vmx->nested.nested_vmx_secondary_ctls_high ] Signed-off-by: Luis Henriques --- arch/x86/kvm/vmx.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 2557e8e2193db..aa6bd8cc914ce 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2348,8 +2348,7 @@ 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; @@ -2363,6 +2362,10 @@ 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; -- 2.47.3