KVM: nVMX: fix nested EPT detection

The nested_ept_enabled flag introduced in commit 7ca29de2136 was not
computed correctly. We are interested only in L1's EPT state, not the
the combined L0+L1 value.

In particular, if L0 uses EPT but L1 does not, nested_ept_enabled must
be false to make sure that PDPSTRs are loaded based on CR3 as usual,
because the special case described in 26.3.2.4 Loading Page-Directory-
Pointer-Table Entries does not apply.

Fixes: 7ca29de21362 ("KVM: nVMX: fix CR3 load if L2 uses PAE paging and EPT")
Cc: qemu-stable@nongnu.org
Reported-by: Wanpeng Li <wanpeng.li@hotmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Ladi Prosek <lprosek@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 7ad658b693536741c37b16aeb07840a2ce75f5b9)
OraBug: 26628813 KVM: nVMX: fix CR3 load if L2 uses PAE paging and EPT - backport+regression fix
Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: Jack Vogel <jack.vogel@oracle.com>
Tested-by: Eyal Moscovici <eyal.moscovici@oracle.com>
Tested-by: Chris Kenna <chris.kenna@oracle.com>
Acked-by: Konrad Wilk <konrad.wilk@oracle.com>

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 21492d6d85efd440f688f6537e4b25b4a15caa1b..88dad40c19fe1300c5300a0f1b8aa416f743be63 100644 (file)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -9133,7 +9133,6 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
 {
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        u32 exec_control;
-       bool nested_ept_enabled = false;
 
        vmcs_write16(GUEST_ES_SELECTOR, vmcs12->guest_es_selector);
        vmcs_write16(GUEST_CS_SELECTOR, vmcs12->guest_cs_selector);
@@ -9294,7 +9293,6 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
                                vmcs12->guest_intr_status);
                }
 
-               nested_ept_enabled = (exec_control & SECONDARY_EXEC_ENABLE_EPT) != 0;
                vmcs_write32(SECONDARY_VM_EXEC_CONTROL, exec_control);
        }
 
@@ -9423,7 +9421,7 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
        vmcs_writel(CR4_READ_SHADOW, nested_read_cr4(vmcs12));
 
        /* Shadow page tables on either EPT or shadow page tables. */
-       if (nested_vmx_load_cr3(vcpu, vmcs12->guest_cr3, nested_ept_enabled,
+       if (nested_vmx_load_cr3(vcpu, vmcs12->guest_cr3, nested_cpu_has_ept(vmcs12),
                                entry_failure_code))
                return 1;