Merge tag 'kvm-3.6-2' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Avi Kivity:
 "A trio of KVM fixes: incorrect lookup of guest cpuid, an uninitialized
  variable fix, and error path cleanup fix."

* tag 'kvm-3.6-2' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: fix error paths for failed gfn_to_page() calls
  KVM: x86: Check INVPCID feature bit in EBX of leaf 7
  KVM: PIC: fix use of uninitialised variable.

3 files changed, 29 insertions, 9 deletions

diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c
index e498b18f010..9fc9aa7ac70 100644
--- a/arch/x86/kvm/i8259.c
+++ b/arch/x86/kvm/i8259.c
@@ -318,7 +318,7 @@ static void pic_ioport_write(void *opaque, u32 addr, u32 val)
                 if (val & 0x10) {
                         u8 edge_irr = s->irr & ~s->elcr;
                         int i;
-                        bool found;
+                        bool found = false;
                         struct kvm_vcpu *vcpu;
 
                         s->init4 = val & 1;
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index c00f03de1b7..b1eb202ee76 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -3619,6 +3619,7 @@ static void seg_setup(int seg)
 
 static int alloc_apic_access_page(struct kvm *kvm)
 {
+        struct page *page;
         struct kvm_userspace_memory_region kvm_userspace_mem;
         int r = 0;
 
@@ -3633,7 +3634,13 @@ static int alloc_apic_access_page(struct kvm *kvm)
         if (r)
                 goto out;
 
-        kvm->arch.apic_access_page = gfn_to_page(kvm, 0xfee00);
+        page = gfn_to_page(kvm, 0xfee00);
+        if (is_error_page(page)) {
+                r = -EFAULT;
+                goto out;
+        }
+
+        kvm->arch.apic_access_page = page;
 out:
         mutex_unlock(&kvm->slots_lock);
         return r;
@@ -3641,6 +3648,7 @@ out:
 
 static int alloc_identity_pagetable(struct kvm *kvm)
 {
+        struct page *page;
         struct kvm_userspace_memory_region kvm_userspace_mem;
         int r = 0;
 
@@ -3656,8 +3664,13 @@ static int alloc_identity_pagetable(struct kvm *kvm)
         if (r)
                 goto out;
 
-        kvm->arch.ept_identity_pagetable = gfn_to_page(kvm,
-                        kvm->arch.ept_identity_map_addr >> PAGE_SHIFT);
+        page = gfn_to_page(kvm, kvm->arch.ept_identity_map_addr >> PAGE_SHIFT);
+        if (is_error_page(page)) {
+                r = -EFAULT;
+                goto out;
+        }
+
+        kvm->arch.ept_identity_pagetable = page;
 out:
         mutex_unlock(&kvm->slots_lock);
         return r;
@@ -6575,7 +6588,7 @@ static void vmx_cpuid_update(struct kvm_vcpu *vcpu)
         /* Exposing INVPCID only when PCID is exposed */
         best = kvm_find_cpuid_entry(vcpu, 0x7, 0);
         if (vmx_invpcid_supported() &&
-            best && (best->ecx & bit(X86_FEATURE_INVPCID)) &&
+            best && (best->ebx & bit(X86_FEATURE_INVPCID)) &&
             guest_cpuid_has_pcid(vcpu)) {
                 exec_control |= SECONDARY_EXEC_ENABLE_INVPCID;
                 vmcs_write32(SECONDARY_VM_EXEC_CONTROL,
@@ -6585,7 +6598,7 @@ static void vmx_cpuid_update(struct kvm_vcpu *vcpu)
                 vmcs_write32(SECONDARY_VM_EXEC_CONTROL,
                              exec_control);
                 if (best)
-                        best->ecx &= ~bit(X86_FEATURE_INVPCID);
+                        best->ebx &= ~bit(X86_FEATURE_INVPCID);
         }
 }
 
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 148ed666e31..2966c847d48 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5113,17 +5113,20 @@ static void post_kvm_run_save(struct kvm_vcpu *vcpu)
                         !kvm_event_needs_reinjection(vcpu);
 }
 
-static void vapic_enter(struct kvm_vcpu *vcpu)
+static int vapic_enter(struct kvm_vcpu *vcpu)
 {
         struct kvm_lapic *apic = vcpu->arch.apic;
         struct page *page;
 
         if (!apic || !apic->vapic_addr)
-                return;
+                return 0;
 
         page = gfn_to_page(vcpu->kvm, apic->vapic_addr >> PAGE_SHIFT);
+        if (is_error_page(page))
+                return -EFAULT;
 
         vcpu->arch.apic->vapic_page = page;
+        return 0;
 }
 
 static void vapic_exit(struct kvm_vcpu *vcpu)
@@ -5430,7 +5433,11 @@ static int __vcpu_run(struct kvm_vcpu *vcpu)
         }
 
         vcpu->srcu_idx = srcu_read_lock(&kvm->srcu);
-        vapic_enter(vcpu);
+        r = vapic_enter(vcpu);
+        if (r) {
+                srcu_read_unlock(&kvm->srcu, vcpu->srcu_idx);
+                return r;
+        }
 
         r = 1;
         while (r > 0) {