Messages in this thread Patch in this message | | | From | Kamal Mostafa <> | Subject | [PATCH 3.13.y-ckt 25/90] KVM: nVMX: mask unrestricted_guest if disabled on L0 | Date | Tue, 5 May 2015 13:53:57 -0700 |
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3.13.11-ckt20 -stable review patch. If anyone has any objections, please let me know.
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From: =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= <rkrcmar@redhat.com>
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 <kchamart@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> [ kamal: backport to 3.13-stable: context ] Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- arch/x86/kvm/vmx.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 2ff437d..9c2c662 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2260,8 +2260,8 @@ 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; @@ -2276,6 +2276,10 @@ 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_PREEMPTION_TIMER_RATE_MASK | -- 1.9.1
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