From 2be3bcbfe84713c49a42041baf3451e20a381355 Mon Sep 17 00:00:00 2001 From: Keir Fraser Date: Fri, 20 May 2011 09:06:58 +0100 Subject: [PATCH] nestedsvm: reduce TLB flushes Reduce TLB flushes: 1. When we update the cr3 during VMRUN/VMEXIT emulation we toggle between n1asid and n2asid forth and back => no TLB flush needed 2. Only flush n1asid or n2asid depending on vcpu guest mode and not both unconditionally. Signed-off-by: Christoph Egger Signed-off-by: Keir Fraser --- xen/arch/x86/hvm/svm/svm.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/xen/arch/x86/hvm/svm/svm.c b/xen/arch/x86/hvm/svm/svm.c index b342897812..8b1557b8ca 100644 --- a/xen/arch/x86/hvm/svm/svm.c +++ b/xen/arch/x86/hvm/svm/svm.c @@ -451,7 +451,14 @@ static void svm_update_guest_cr(struct vcpu *v, unsigned int cr) break; case 3: vmcb_set_cr3(vmcb, v->arch.hvm_vcpu.hw_cr[3]); - hvm_asid_flush_vcpu(v); + if ( !nestedhvm_enabled(v->domain) ) + hvm_asid_flush_vcpu(v); + else if ( nestedhvm_vmswitch_in_progress(v) ) + ; /* We toggle between n1asid/n2asid -> no flush required. */ + else + hvm_asid_flush_vcpu_asid( + nestedhvm_vcpu_in_guestmode(v) + ? &vcpu_nestedhvm(v).nv_n2asid : &v->arch.hvm_vcpu.n1asid); break; case 4: value = HVM_CR4_HOST_MASK; -- 2.30.2