KVM: x86 emulator: add get_cached_segment_base() callback to x86_emulate_ops
On VMX it is expensive to call get_cached_descriptor() just to get segment
base since multiple vmcs_reads are done instead of only one. Introduce
new call back get_cached_segment_base() for efficiency.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index e3a5455..9a469df 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3714,6 +3714,12 @@
kvm_x86_ops->get_gdt(vcpu, dt);
}
+static unsigned long emulator_get_cached_segment_base(int seg,
+ struct kvm_vcpu *vcpu)
+{
+ return get_segment_base(vcpu, seg);
+}
+
static bool emulator_get_cached_descriptor(struct desc_struct *desc, int seg,
struct kvm_vcpu *vcpu)
{
@@ -3804,6 +3810,7 @@
.set_cached_descriptor = emulator_set_cached_descriptor,
.get_segment_selector = emulator_get_segment_selector,
.set_segment_selector = emulator_set_segment_selector,
+ .get_cached_segment_base = emulator_get_cached_segment_base,
.get_gdt = emulator_get_gdt,
.get_cr = emulator_get_cr,
.set_cr = emulator_set_cr,