KVM: Add accessor for reading cr4 (or some bits of cr4)

Some bits of cr4 can be owned by the guest on vmx, so when we read them,
we copy them to the vcpu structure.  In preparation for making the set of
guest-owned bits dynamic, use helpers to access these bits so we don't need
to know where the bit resides.

No changes to svm since all bits are host-owned there.

Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 6 insertions, 10 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 27931867791..84dd33e717f 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -482,7 +482,7 @@ EXPORT_SYMBOL_GPL(kvm_lmsw);
 
 void kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
 {
-        unsigned long old_cr4 = vcpu->arch.cr4;
+        unsigned long old_cr4 = kvm_read_cr4(vcpu);
         unsigned long pdptr_bits = X86_CR4_PGE | X86_CR4_PSE | X86_CR4_PAE;
 
         if (cr4 & CR4_RESERVED_BITS) {
@@ -1899,7 +1899,7 @@ static int kvm_vcpu_ioctl_x86_set_mce(struct kvm_vcpu *vcpu,
                 return 0;
         if (mce->status & MCI_STATUS_UC) {
                 if ((vcpu->arch.mcg_status & MCG_STATUS_MCIP) ||
-                    !(vcpu->arch.cr4 & X86_CR4_MCE)) {
+                    !kvm_read_cr4_bits(vcpu, X86_CR4_MCE)) {
                         printk(KERN_DEBUG "kvm: set_mce: "
                                "injects mce exception while "
                                "previous one is in progress!\n");
@@ -3616,7 +3616,6 @@ unsigned long realmode_get_cr(struct kvm_vcpu *vcpu, int cr)
 {
         unsigned long value;
 
-        kvm_x86_ops->decache_cr4_guest_bits(vcpu);
         switch (cr) {
         case 0:
                 value = vcpu->arch.cr0;
@@ -3628,7 +3627,7 @@ unsigned long realmode_get_cr(struct kvm_vcpu *vcpu, int cr)
                 value = vcpu->arch.cr3;
                 break;
         case 4:
-                value = vcpu->arch.cr4;
+                value = kvm_read_cr4(vcpu);
                 break;
         case 8:
                 value = kvm_get_cr8(vcpu);
@@ -3656,7 +3655,7 @@ void realmode_set_cr(struct kvm_vcpu *vcpu, int cr, unsigned long val,
                 kvm_set_cr3(vcpu, val);
                 break;
         case 4:
-                kvm_set_cr4(vcpu, mk_cr_64(vcpu->arch.cr4, val));
+                kvm_set_cr4(vcpu, mk_cr_64(kvm_read_cr4(vcpu), val));
                 break;
         case 8:
                 kvm_set_cr8(vcpu, val & 0xfUL);
@@ -4237,11 +4236,10 @@ int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
         sregs->gdt.limit = dt.limit;
         sregs->gdt.base = dt.base;
 
-        kvm_x86_ops->decache_cr4_guest_bits(vcpu);
         sregs->cr0 = vcpu->arch.cr0;
         sregs->cr2 = vcpu->arch.cr2;
         sregs->cr3 = vcpu->arch.cr3;
-        sregs->cr4 = vcpu->arch.cr4;
+        sregs->cr4 = kvm_read_cr4(vcpu);
         sregs->cr8 = kvm_get_cr8(vcpu);
         sregs->efer = vcpu->arch.shadow_efer;
         sregs->apic_base = kvm_get_apic_base(vcpu);
@@ -4737,13 +4735,11 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
         kvm_x86_ops->set_efer(vcpu, sregs->efer);
         kvm_set_apic_base(vcpu, sregs->apic_base);
 
-        kvm_x86_ops->decache_cr4_guest_bits(vcpu);
-
         mmu_reset_needed |= vcpu->arch.cr0 != sregs->cr0;
         kvm_x86_ops->set_cr0(vcpu, sregs->cr0);
         vcpu->arch.cr0 = sregs->cr0;
 
-        mmu_reset_needed |= vcpu->arch.cr4 != sregs->cr4;
+        mmu_reset_needed |= kvm_read_cr4(vcpu) != sregs->cr4;
         kvm_x86_ops->set_cr4(vcpu, sregs->cr4);
         if (!is_long_mode(vcpu) && is_pae(vcpu)) {
                 load_pdptrs(vcpu, vcpu->arch.cr3);