KVM: nVMX: Refactor IO bitmap checks into helper function

Checks against the IO bitmap are useful for both instruction emulation
and VM-exit reflection. Refactor the IO bitmap checks into a helper
function.

Signed-off-by: Oliver Upton <oupton@google.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 50d8dbb..f979832 100644 (file)
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -5312,24 +5312,17 @@ fail:
        return 1;
 }
 
-
-static bool nested_vmx_exit_handled_io(struct kvm_vcpu *vcpu,
-                                      struct vmcs12 *vmcs12)
+/*
+ * Return true if an IO instruction with the specified port and size should cause
+ * a VM-exit into L1.
+ */
+bool nested_vmx_check_io_bitmaps(struct kvm_vcpu *vcpu, unsigned int port,
+                                int size)
 {
-       unsigned long exit_qualification;
+       struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
        gpa_t bitmap, last_bitmap;
-       unsigned int port;
-       int size;
        u8 b;
 
-       if (!nested_cpu_has(vmcs12, CPU_BASED_USE_IO_BITMAPS))
-               return nested_cpu_has(vmcs12, CPU_BASED_UNCOND_IO_EXITING);
-
-       exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
-
-       port = exit_qualification >> 16;
-       size = (exit_qualification & 7) + 1;
-
        last_bitmap = (gpa_t)-1;
        b = -1;
 
@@ -5356,6 +5349,24 @@ static bool nested_vmx_exit_handled_io(struct kvm_vcpu *vcpu,
        return false;
 }
 
+static bool nested_vmx_exit_handled_io(struct kvm_vcpu *vcpu,
+                                      struct vmcs12 *vmcs12)
+{
+       unsigned long exit_qualification;
+       unsigned int port;
+       int size;
+
+       if (!nested_cpu_has(vmcs12, CPU_BASED_USE_IO_BITMAPS))
+               return nested_cpu_has(vmcs12, CPU_BASED_UNCOND_IO_EXITING);
+
+       exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
+
+       port = exit_qualification >> 16;
+       size = (exit_qualification & 7) + 1;
+
+       return nested_vmx_check_io_bitmaps(vcpu, port, size);
+}
+
 /*
  * Return 1 if we should exit from L2 to L1 to handle an MSR access,
  * rather than handle it ourselves in L0. I.e., check whether L1 expressed

diff --git a/arch/x86/kvm/vmx/nested.h b/arch/x86/kvm/vmx/nested.h
index 1db388f..9aeda46 100644 (file)
--- a/arch/x86/kvm/vmx/nested.h
+++ b/arch/x86/kvm/vmx/nested.h
@@ -33,6 +33,8 @@ int vmx_get_vmx_msr(struct nested_vmx_msrs *msrs, u32 msr_index, u64 *pdata);
 int get_vmx_mem_address(struct kvm_vcpu *vcpu, unsigned long exit_qualification,
                        u32 vmx_instruction_info, bool wr, int len, gva_t *ret);
 void nested_vmx_pmu_entry_exit_ctls_update(struct kvm_vcpu *vcpu);
+bool nested_vmx_check_io_bitmaps(struct kvm_vcpu *vcpu, unsigned int port,
+                                int size);
 
 static inline struct vmcs12 *get_vmcs12(struct kvm_vcpu *vcpu)
 {