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Diffstat (limited to 'arch/x86/kvm/vmx.c')
-rw-r--r--arch/x86/kvm/vmx.c17
1 files changed, 15 insertions, 2 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 3a727ca02f2..eda2cb619c2 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2121,7 +2121,7 @@ static void ept_save_pdptrs(struct kvm_vcpu *vcpu)
(unsigned long *)&vcpu->arch.regs_dirty);
}
-static void vmx_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4);
+static int vmx_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4);
static void ept_update_paging_mode_cr0(unsigned long *hw_cr0,
unsigned long cr0,
@@ -2219,11 +2219,23 @@ static void vmx_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
vmcs_writel(GUEST_CR3, guest_cr3);
}
-static void vmx_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
+static int vmx_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
{
unsigned long hw_cr4 = cr4 | (to_vmx(vcpu)->rmode.vm86_active ?
KVM_RMODE_VM_CR4_ALWAYS_ON : KVM_PMODE_VM_CR4_ALWAYS_ON);
+ if (cr4 & X86_CR4_VMXE) {
+ /*
+ * To use VMXON (and later other VMX instructions), a guest
+ * must first be able to turn on cr4.VMXE (see handle_vmon()).
+ * So basically the check on whether to allow nested VMX
+ * is here.
+ */
+ if (!nested_vmx_allowed(vcpu))
+ return 1;
+ } else if (to_vmx(vcpu)->nested.vmxon)
+ return 1;
+
vcpu->arch.cr4 = cr4;
if (enable_ept) {
if (!is_paging(vcpu)) {
@@ -2236,6 +2248,7 @@ static void vmx_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
vmcs_writel(CR4_READ_SHADOW, cr4);
vmcs_writel(GUEST_CR4, hw_cr4);
+ return 0;
}
static void vmx_get_segment(struct kvm_vcpu *vcpu,