[PATCH] KVM: Simplify is_long_mode()

Instead of doing tricky stuff with the arch dependent virtualization
registers, take a peek at the guest's efer.

This simlifies some code, and fixes some confusion in the mmu branch.

Signed-off-by: Avi Kivity <avi@qumranet.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

6 files changed, 14 insertions, 18 deletions

diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index 930e04ce1af6..c2db4218d6cc 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -278,7 +278,6 @@ struct kvm_arch_ops {
                             struct kvm_segment *var, int seg);
         void (*set_segment)(struct kvm_vcpu *vcpu,
                             struct kvm_segment *var, int seg);
-        int (*is_long_mode)(struct kvm_vcpu *vcpu);
         void (*get_cs_db_l_bits)(struct kvm_vcpu *vcpu, int *db, int *l);
         void (*set_cr0)(struct kvm_vcpu *vcpu, unsigned long cr0);
         void (*set_cr0_no_modeswitch)(struct kvm_vcpu *vcpu,
@@ -403,6 +402,15 @@ static inline struct page *_gfn_to_page(struct kvm *kvm, gfn_t gfn)
         return (slot) ? slot->phys_mem[gfn - slot->base_gfn] : NULL;
 }
 
+static inline int is_long_mode(struct kvm_vcpu *vcpu)
+{
+#ifdef CONFIG_X86_64
+        return vcpu->shadow_efer & EFER_LME;
+#else
+        return 0;
+#endif
+}
+
 static inline int is_pae(struct kvm_vcpu *vcpu)
 {
         return vcpu->cr4 & CR4_PAE_MASK;
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 9f24f22e4cb2..38375e2bb703 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -398,7 +398,7 @@ void set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
                 return;
         }
 
-        if (kvm_arch_ops->is_long_mode(vcpu)) {
+        if (is_long_mode(vcpu)) {
                 if (!(cr4 & CR4_PAE_MASK)) {
                         printk(KERN_DEBUG "set_cr4: #GP, clearing PAE while "
                                "in long mode\n");
@@ -425,7 +425,7 @@ EXPORT_SYMBOL_GPL(set_cr4);
 
 void set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
 {
-        if (kvm_arch_ops->is_long_mode(vcpu)) {
+        if (is_long_mode(vcpu)) {
                 if ( cr3 & CR3_L_MODE_RESEVED_BITS) {
                         printk(KERN_DEBUG "set_cr3: #GP, reserved bits\n");
                         inject_gp(vcpu);
diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c
index bdffe83b19e8..85887fcd584f 100644
--- a/drivers/kvm/mmu.c
+++ b/drivers/kvm/mmu.c
@@ -578,7 +578,7 @@ static int init_kvm_mmu(struct kvm_vcpu *vcpu)
 
         if (!is_paging(vcpu))
                 return nonpaging_init_context(vcpu);
-        else if (kvm_arch_ops->is_long_mode(vcpu))
+        else if (is_long_mode(vcpu))
                 return paging64_init_context(vcpu);
         else if (is_pae(vcpu))
                 return paging32E_init_context(vcpu);
diff --git a/drivers/kvm/paging_tmpl.h b/drivers/kvm/paging_tmpl.h
index a9771b4c5bb8..09bb9b4ed12d 100644
--- a/drivers/kvm/paging_tmpl.h
+++ b/drivers/kvm/paging_tmpl.h
@@ -68,7 +68,7 @@ static void FNAME(init_walker)(struct guest_walker *walker,
         hpa = safe_gpa_to_hpa(vcpu, vcpu->cr3 & PT64_BASE_ADDR_MASK);
         walker->table = kmap_atomic(pfn_to_page(hpa >> PAGE_SHIFT), KM_USER0);
 
-        ASSERT((!kvm_arch_ops->is_long_mode(vcpu) && is_pae(vcpu)) ||
+        ASSERT((!is_long_mode(vcpu) && is_pae(vcpu)) ||
                (vcpu->cr3 & ~(PAGE_MASK | CR3_FLAGS_MASK)) == 0);
 
         walker->table = (pt_element_t *)( (unsigned long)walker->table |
@@ -131,7 +131,7 @@ static pt_element_t *FNAME(fetch_guest)(struct kvm_vcpu *vcpu,
                      (walker->table[index] & PT_PAGE_SIZE_MASK) &&
                      (PTTYPE == 64 || is_pse(vcpu))))
                         return &walker->table[index];
-                if (walker->level != 3 || kvm_arch_ops->is_long_mode(vcpu))
+                if (walker->level != 3 || is_long_mode(vcpu))
                         walker->inherited_ar &= walker->table[index];
                 paddr = safe_gpa_to_hpa(vcpu, walker->table[index] & PT_BASE_ADDR_MASK);
                 kunmap_atomic(walker->table, KM_USER0);
diff --git a/drivers/kvm/svm.c b/drivers/kvm/svm.c
index 283024ab3ba0..68124c0bf630 100644
--- a/drivers/kvm/svm.c
+++ b/drivers/kvm/svm.c
@@ -166,11 +166,6 @@ static inline void write_dr7(unsigned long val)
         asm volatile ("mov %0, %%dr7" :: "r" (val));
 }
 
-static inline int svm_is_long_mode(struct kvm_vcpu *vcpu)
-{
-        return vcpu->svm->vmcb->save.efer & KVM_EFER_LMA;
-}
-
 static inline void force_new_asid(struct kvm_vcpu *vcpu)
 {
         vcpu->svm->asid_generation--;
@@ -1609,7 +1604,6 @@ static struct kvm_arch_ops svm_arch_ops = {
         .get_segment_base = svm_get_segment_base,
         .get_segment = svm_get_segment,
         .set_segment = svm_set_segment,
-        .is_long_mode = svm_is_long_mode,
         .get_cs_db_l_bits = svm_get_cs_db_l_bits,
         .set_cr0 = svm_set_cr0,
         .set_cr0_no_modeswitch = svm_set_cr0,
diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index 983a15b1977c..603a4135de42 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -900,11 +900,6 @@ static void vmx_set_segment(struct kvm_vcpu *vcpu,
         vmcs_write32(sf->ar_bytes, ar);
 }
 
-static int vmx_is_long_mode(struct kvm_vcpu *vcpu)
-{
-        return vmcs_read32(VM_ENTRY_CONTROLS) & VM_ENTRY_CONTROLS_IA32E_MASK;
-}
-
 static void vmx_get_cs_db_l_bits(struct kvm_vcpu *vcpu, int *db, int *l)
 {
         u32 ar = vmcs_read32(GUEST_CS_AR_BYTES);
@@ -1975,7 +1970,6 @@ static struct kvm_arch_ops vmx_arch_ops = {
         .get_segment_base = vmx_get_segment_base,
         .get_segment = vmx_get_segment,
         .set_segment = vmx_set_segment,
-        .is_long_mode = vmx_is_long_mode,
         .get_cs_db_l_bits = vmx_get_cs_db_l_bits,
         .set_cr0 = vmx_set_cr0,
         .set_cr0_no_modeswitch = vmx_set_cr0_no_modeswitch,