[PATCH 4.19 71/97] KVM: nVMX: Refactor IO bitmap checks into helper function

Greg Kroah-Hartman
2020-02-27T14:30:04Z

From: Oliver Upton <oupton@google.com>

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@google.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/x86/kvm/vmx.c | 40 +++++++++++++++++++++++++++-------------
1 file changed, 27 insertions(+), 13 deletions(-)

--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -5725,6 +5725,26 @@ static bool cs_ss_rpl_check(struct kvm_v
(ss.selector & SEGMENT_RPL_MASK));
}

+static bool nested_vmx_check_io_bitmaps(struct kvm_vcpu *vcpu,
+ unsigned int port, int size);
+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);
+}
+
/*
* Check if guest state is valid. Returns true if valid, false if
* not.
@@ -9469,23 +9489,17 @@ static int (*const kvm_vmx_exit_handlers
static const int kvm_vmx_max_exit_handlers =
ARRAY_SIZE(kvm_vmx_exit_handlers);

-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;