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-rw-r--r--arch/x86/include/asm/kvm_host.h2
-rw-r--r--arch/x86/kvm/svm.c6
-rw-r--r--arch/x86/kvm/vmx.c17
-rw-r--r--arch/x86/kvm/x86.c4
4 files changed, 22 insertions, 7 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index ff17deb6e98..d167039ecdf 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -555,7 +555,7 @@ struct kvm_x86_ops {
void (*decache_cr4_guest_bits)(struct kvm_vcpu *vcpu);
void (*set_cr0)(struct kvm_vcpu *vcpu, unsigned long cr0);
void (*set_cr3)(struct kvm_vcpu *vcpu, unsigned long cr3);
- void (*set_cr4)(struct kvm_vcpu *vcpu, unsigned long cr4);
+ int (*set_cr4)(struct kvm_vcpu *vcpu, unsigned long cr4);
void (*set_efer)(struct kvm_vcpu *vcpu, u64 efer);
void (*get_idt)(struct kvm_vcpu *vcpu, struct desc_ptr *dt);
void (*set_idt)(struct kvm_vcpu *vcpu, struct desc_ptr *dt);
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 506e4fe23ad..475d1c94850 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1496,11 +1496,14 @@ static void svm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
update_cr0_intercept(svm);
}
-static void svm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
+static int svm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
{
unsigned long host_cr4_mce = read_cr4() & X86_CR4_MCE;
unsigned long old_cr4 = to_svm(vcpu)->vmcb->save.cr4;
+ if (cr4 & X86_CR4_VMXE)
+ return 1;
+
if (npt_enabled && ((old_cr4 ^ cr4) & X86_CR4_PGE))
svm_flush_tlb(vcpu);
@@ -1510,6 +1513,7 @@ static void svm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
cr4 |= host_cr4_mce;
to_svm(vcpu)->vmcb->save.cr4 = cr4;
mark_dirty(to_svm(vcpu)->vmcb, VMCB_CR);
+ return 0;
}
static void svm_set_segment(struct kvm_vcpu *vcpu,
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,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index d88de565d0c..460932b62c5 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -615,11 +615,9 @@ int kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
kvm_read_cr3(vcpu)))
return 1;
- if (cr4 & X86_CR4_VMXE)
+ if (kvm_x86_ops->set_cr4(vcpu, cr4))
return 1;
- kvm_x86_ops->set_cr4(vcpu, cr4);
-
if ((cr4 ^ old_cr4) & pdptr_bits)
kvm_mmu_reset_context(vcpu);