KVM: nVMX: Check IO instruction VM-exit conditions

Consult the 'unconditional IO exiting' and 'use IO bitmaps' VM-execution
controls when checking instruction interception. If the 'use IO bitmaps'
VM-execution control is 1, check the instruction access against the IO
bitmaps to determine if the instruction causes a VM-exit.

Signed-off-by: Oliver Upton <oupton@google.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 f979832..e920d78 100644 (file)
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -5353,7 +5353,7 @@ static bool nested_vmx_exit_handled_io(struct kvm_vcpu *vcpu,
                                       struct vmcs12 *vmcs12)
 {
        unsigned long exit_qualification;
-       unsigned int port;
+       unsigned short port;
        int size;
 
        if (!nested_cpu_has(vmcs12, CPU_BASED_USE_IO_BITMAPS))

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 5801a86..63aaf44 100644 (file)
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7145,6 +7145,39 @@ static void vmx_request_immediate_exit(struct kvm_vcpu *vcpu)
        to_vmx(vcpu)->req_immediate_exit = true;
 }
 
+static int vmx_check_intercept_io(struct kvm_vcpu *vcpu,
+                                 struct x86_instruction_info *info)
+{
+       struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
+       unsigned short port;
+       bool intercept;
+       int size;
+
+       if (info->intercept == x86_intercept_in ||
+           info->intercept == x86_intercept_ins) {
+               port = info->src_val;
+               size = info->dst_bytes;
+       } else {
+               port = info->dst_val;
+               size = info->src_bytes;
+       }
+
+       /*
+        * If the 'use IO bitmaps' VM-execution control is 0, IO instruction
+        * VM-exits depend on the 'unconditional IO exiting' VM-execution
+        * control.
+        *
+        * Otherwise, IO instruction VM-exits are controlled by the IO bitmaps.
+        */
+       if (!nested_cpu_has(vmcs12, CPU_BASED_USE_IO_BITMAPS))
+               intercept = nested_cpu_has(vmcs12,
+                                          CPU_BASED_UNCOND_IO_EXITING);
+       else
+               intercept = nested_vmx_check_io_bitmaps(vcpu, port, size);
+
+       return intercept ? X86EMUL_UNHANDLEABLE : X86EMUL_CONTINUE;
+}
+
 static int vmx_check_intercept(struct kvm_vcpu *vcpu,
                               struct x86_instruction_info *info,
                               enum x86_intercept_stage stage)
@@ -7152,18 +7185,30 @@ static int vmx_check_intercept(struct kvm_vcpu *vcpu,
        struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
        struct x86_emulate_ctxt *ctxt = &vcpu->arch.emulate_ctxt;
 
+       switch (info->intercept) {
        /*
         * RDPID causes #UD if disabled through secondary execution controls.
         * Because it is marked as EmulateOnUD, we need to intercept it here.
         */
-       if (info->intercept == x86_intercept_rdtscp &&
-           !nested_cpu_has2(vmcs12, SECONDARY_EXEC_RDTSCP)) {
-               ctxt->exception.vector = UD_VECTOR;
-               ctxt->exception.error_code_valid = false;
-               return X86EMUL_PROPAGATE_FAULT;
-       }
+       case x86_intercept_rdtscp:
+               if (!nested_cpu_has2(vmcs12, SECONDARY_EXEC_RDTSCP)) {
+                       ctxt->exception.vector = UD_VECTOR;
+                       ctxt->exception.error_code_valid = false;
+                       return X86EMUL_PROPAGATE_FAULT;
+               }
+               break;
+
+       case x86_intercept_in:
+       case x86_intercept_ins:
+       case x86_intercept_out:
+       case x86_intercept_outs:
+               return vmx_check_intercept_io(vcpu, info);
 
        /* TODO: check more intercepts... */
+       default:
+               break;
+       }
+
        return X86EMUL_UNHANDLEABLE;
 }