[PATCH 5.5 098/150] KVM: nVMX: Refactor IO bitmap checks into helper function

From: Greg Kroah-Hartman
Date: Thu Feb 27 2020 - 09:16:48 EST


From: Oliver Upton <oupton@xxxxxxxxxx>

commit e71237d3ff1abf9f3388337cfebf53b96df2020d upstream.

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@xxxxxxxxxx>
Reviewed-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/x86/kvm/vmx/nested.c | 39 +++++++++++++++++++++++++--------------
arch/x86/kvm/vmx/nested.h | 2 ++
2 files changed, 27 insertions(+), 14 deletions(-)

--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -5304,24 +5304,17 @@ 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;

@@ -5348,6 +5341,24 @@ static bool nested_vmx_exit_handled_io(s
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 access,
* rather than handle it ourselves in L0. I.e., check whether L1 expressed
--- a/arch/x86/kvm/vmx/nested.h
+++ b/arch/x86/kvm/vmx/nested.h
@@ -34,6 +34,8 @@ int vmx_get_vmx_msr(struct nested_vmx_ms
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)
{