kvm: nVMX: Allow L1 to intercept software exceptions (#BP and #OF)

commit ef85b67385436ddc1998f45f1d6a210f935b3388 upstream.

When L2 exits to L0 due to "exception or NMI", software exceptions
(#BP and #OF) for which L1 has requested an intercept should be
handled by L1 rather than L0. Previously, only hardware exceptions
were forwarded to L1.

Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index bd0ed47..0fb33a0 100644 (file)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -876,10 +876,10 @@ static inline bool nested_cpu_has_virtual_nmis(struct vmcs12 *vmcs12,
        return vmcs12->pin_based_vm_exec_control & PIN_BASED_VIRTUAL_NMIS;
 }
 
        return vmcs12->pin_based_vm_exec_control & PIN_BASED_VIRTUAL_NMIS;
 }
 

-static inline bool is_exception(u32 intr_info)
+static inline bool is_nmi(u32 intr_info)

 {
        return (intr_info & (INTR_INFO_INTR_TYPE_MASK | INTR_INFO_VALID_MASK))
 {
        return (intr_info & (INTR_INFO_INTR_TYPE_MASK | INTR_INFO_VALID_MASK))

-               == (INTR_TYPE_HARD_EXCEPTION | INTR_INFO_VALID_MASK);
+               == (INTR_TYPE_NMI_INTR | INTR_INFO_VALID_MASK);

 }
 
 static void nested_vmx_vmexit(struct kvm_vcpu *vcpu);
 }
 
 static void nested_vmx_vmexit(struct kvm_vcpu *vcpu);


@@ -4225,7 +4225,7 @@ static int handle_exception(struct kvm_vcpu *vcpu)
                return 0;
        }
 
                return 0;
        }
 

-       if ((intr_info & INTR_INFO_INTR_TYPE_MASK) == INTR_TYPE_NMI_INTR)
+       if (is_nmi(intr_info))

                return 1;  /* already handled by vmx_vcpu_run() */
 
        if (is_no_device(intr_info)) {
                return 1;  /* already handled by vmx_vcpu_run() */
 
        if (is_no_device(intr_info)) {


@@ -5773,7 +5773,7 @@ static bool nested_vmx_exit_handled(struct kvm_vcpu *vcpu)
 
        switch (exit_reason) {
        case EXIT_REASON_EXCEPTION_NMI:
 
        switch (exit_reason) {
        case EXIT_REASON_EXCEPTION_NMI:

-               if (!is_exception(intr_info))
+               if (is_nmi(intr_info))

                        return 0;
                else if (is_page_fault(intr_info))
                        return enable_ept;
                        return 0;
                else if (is_page_fault(intr_info))
                        return enable_ept;


@@ -5973,8 +5973,7 @@ static void vmx_complete_atomic_exit(struct vcpu_vmx *vmx)
                kvm_machine_check();
 
        /* We need to handle NMIs before interrupts are enabled */
                kvm_machine_check();
 
        /* We need to handle NMIs before interrupts are enabled */

-       if ((exit_intr_info & INTR_INFO_INTR_TYPE_MASK) == INTR_TYPE_NMI_INTR &&
-           (exit_intr_info & INTR_INFO_VALID_MASK)) {
+       if (is_nmi(exit_intr_info)) {

                kvm_before_handle_nmi(&vmx->vcpu);
                asm("int $2");
                kvm_after_handle_nmi(&vmx->vcpu);
                kvm_before_handle_nmi(&vmx->vcpu);
                asm("int $2");
                kvm_after_handle_nmi(&vmx->vcpu);