KVM: Use standard CR3 flags, tighten checking

The kernel now has asm/cpu-features.h: use those macros instead of inventing
our own.

Also spell out definition of CR3_RESEVED_BITS, fix spelling and
tighten it for the non-PAE case.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Avi Kivity <avi@qumranet.com>

3 files changed, 25 insertions, 19 deletions

diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index 7117c3b3cca7..983c33f38377 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -19,12 +19,9 @@
 #include <linux/kvm.h>
 #include <linux/kvm_para.h>
 
-#define CR3_WPT_MASK (1ULL << 3)
-#define CR3_PCD_MASK (1ULL << 4)
-
-#define CR3_RESEVED_BITS 0x07ULL
-#define CR3_L_MODE_RESEVED_BITS (~((1ULL << 40) - 1) | 0x0fe7ULL)
-#define CR3_FLAGS_MASK ((1ULL << 5) - 1)
+#define CR3_PAE_RESERVED_BITS ((X86_CR3_PWT | X86_CR3_PCD) - 1)
+#define CR3_NONPAE_RESERVED_BITS ((PAGE_SIZE-1) & ~(X86_CR3_PWT | X86_CR3_PCD))
+#define CR3_L_MODE_RESERVED_BITS (CR3_NONPAE_RESERVED_BITS|0xFFFFFF0000000000ULL)
 
 #define CR4_VME_MASK (1ULL << 0)
 #define CR4_PSE_MASK (1ULL << 4)
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 5d8febe580de..34a571dee514 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -571,23 +571,32 @@ EXPORT_SYMBOL_GPL(set_cr4);
 void set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
 {
         if (is_long_mode(vcpu)) {
-                if (cr3 & CR3_L_MODE_RESEVED_BITS) {
+                if (cr3 & CR3_L_MODE_RESERVED_BITS) {
                         printk(KERN_DEBUG "set_cr3: #GP, reserved bits\n");
                         inject_gp(vcpu);
                         return;
                 }
         } else {
-                if (cr3 & CR3_RESEVED_BITS) {
-                        printk(KERN_DEBUG "set_cr3: #GP, reserved bits\n");
-                        inject_gp(vcpu);
-                        return;
-                }
-                if (is_paging(vcpu) && is_pae(vcpu) &&
-                    !load_pdptrs(vcpu, cr3)) {
-                        printk(KERN_DEBUG "set_cr3: #GP, pdptrs "
-                               "reserved bits\n");
-                        inject_gp(vcpu);
-                        return;
+                if (is_pae(vcpu)) {
+                        if (cr3 & CR3_PAE_RESERVED_BITS) {
+                                printk(KERN_DEBUG
+                                       "set_cr3: #GP, reserved bits\n");
+                                inject_gp(vcpu);
+                                return;
+                        }
+                        if (is_paging(vcpu) && !load_pdptrs(vcpu, cr3)) {
+                                printk(KERN_DEBUG "set_cr3: #GP, pdptrs "
+                                       "reserved bits\n");
+                                inject_gp(vcpu);
+                                return;
+                        }
+                } else {
+                        if (cr3 & CR3_NONPAE_RESERVED_BITS) {
+                                printk(KERN_DEBUG
+                                       "set_cr3: #GP, reserved bits\n");
+                                inject_gp(vcpu);
+                                return;
+                        }
                 }
         }
 
diff --git a/drivers/kvm/paging_tmpl.h b/drivers/kvm/paging_tmpl.h
index 4b5391c717f8..01901ec3fe80 100644
--- a/drivers/kvm/paging_tmpl.h
+++ b/drivers/kvm/paging_tmpl.h
@@ -99,7 +99,7 @@ static int FNAME(walk_addr)(struct guest_walker *walker,
         walker->table = kmap_atomic(pfn_to_page(hpa >> PAGE_SHIFT), KM_USER0);
 
         ASSERT((!is_long_mode(vcpu) && is_pae(vcpu)) ||
-               (vcpu->cr3 & ~(PAGE_MASK | CR3_FLAGS_MASK)) == 0);
+               (vcpu->cr3 & CR3_NONPAE_RESERVED_BITS) == 0);
 
         walker->inherited_ar = PT_USER_MASK | PT_WRITABLE_MASK;