KVM: call cache_all_regs() only once during instruction emulation

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 6 insertions, 8 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index a9a307a75465..f5f2d3d44577 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4459,6 +4459,12 @@ static void init_emulate_ctxt(struct kvm_vcpu *vcpu)
         struct decode_cache *c = &vcpu->arch.emulate_ctxt.decode;
         int cs_db, cs_l;
 
+        /*
+         * TODO: fix emulate.c to use guest_read/write_register
+         * instead of direct ->regs accesses, can save hundred cycles
+         * on Intel for instructions that don't read/change RSP, for
+         * for example.
+         */
         cache_all_regs(vcpu);
 
         kvm_x86_ops->get_cs_db_l_bits(vcpu, &cs_db, &cs_l);
@@ -4562,14 +4568,6 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu,
 
         kvm_clear_exception_queue(vcpu);
 
-        /*
-         * TODO: fix emulate.c to use guest_read/write_register
-         * instead of direct ->regs accesses, can save hundred cycles
-         * on Intel for instructions that don't read/change RSP, for
-         * for example.
-         */
-        cache_all_regs(vcpu);
-
         if (!(emulation_type & EMULTYPE_NO_DECODE)) {
                 init_emulate_ctxt(vcpu);
                 vcpu->arch.emulate_ctxt.interruptibility = 0;