From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexander Graf Subject: Re: [PATCH 2/5] Don't call svm_complete_interrupts for nested guests Date: Wed, 23 Sep 2009 01:04:31 -0700 Message-ID: References: <1253278832-31803-1-git-send-email-agraf@suse.de> <1253278832-31803-2-git-send-email-agraf@suse.de> <1253278832-31803-3-git-send-email-agraf@suse.de> <20090923012640.GC4654@8bytes.org> Mime-Version: 1.0 (iPhone Mail 7A341) Content-Type: text/plain; charset=us-ascii; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit Cc: "kvm@vger.kernel.org" To: Joerg Roedel Return-path: Received: from cantor2.suse.de ([195.135.220.15]:51105 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753836AbZIWIEI (ORCPT ); Wed, 23 Sep 2009 04:04:08 -0400 In-Reply-To: <20090923012640.GC4654@8bytes.org> Sender: kvm-owner@vger.kernel.org List-ID: Am 22.09.2009 um 18:26 schrieb Joerg Roedel : > On Fri, Sep 18, 2009 at 03:00:29PM +0200, Alexander Graf wrote: >> SVM has some cleanup code, that tries to reinject interrupts and >> exceptions >> when the guest didn't manage to deal with them yet. It basically >> transfers >> them to KVM internal state. >> >> Unfortunately, the internal state is reserved for the L1 guest >> state, so we >> shouldn't try to go through that logic when running a nested guest. >> >> When doing something the host KVM can handle, let's just reinject >> the event >> into the L2 guest, because we didn't touch its state anyways. > > I don't really understandt what problem this patch addresses. There > are > situations where we have events to reinject into the l2 guest > directly. > But the generic reinjection code works fine for it. > The only problematic thing with it is that it implicitly relies on > exit_int_info not to be changed in the exit cycle (which would be > worth > a comment). It si > > Joerg > >> >> Signed-off-by: Alexander Graf >> --- >> arch/x86/kvm/svm.c | 18 ++++++++++++++---- >> 1 files changed, 14 insertions(+), 4 deletions(-) >> >> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c >> index f12a669..61efd13 100644 >> --- a/arch/x86/kvm/svm.c >> +++ b/arch/x86/kvm/svm.c >> @@ -2349,7 +2349,10 @@ static int handle_exit(struct kvm_vcpu *vcpu) >> trace_kvm_exit(exit_code, svm->vmcb->save.rip); >> >> if (is_nested(svm)) { >> + struct vmcb_control_area *control = &svm->vmcb->control; >> int vmexit; >> + int type; >> + int vec; >> >> nsvm_printk("nested handle_exit: 0x%x | 0x%lx | 0x%lx | 0x%lx >> \n", >> exit_code, svm->vmcb->control.exit_info_1, >> @@ -2362,9 +2365,18 @@ static int handle_exit(struct kvm_vcpu *vcpu) >> >> if (vmexit == NESTED_EXIT_DONE) >> return 1; >> - } >> >> - svm_complete_interrupts(svm); >> + type = control->exit_int_info & SVM_EXITINTINFO_TYPE_MASK; >> + vec = control->exit_int_info & SVM_EXITINTINFO_VEC_MASK; >> + if ((type == SVM_EXITINTINFO_TYPE_INTR) || >> + ((type == SVM_EXITINTINFO_TYPE_EXEPT) && ! >> kvm_exception_is_soft(vec))) { >> + control->event_inj = control->exit_int_info; >> + control->event_inj_err = control->exit_int_info_err; >> + } >> + } else { >> + /* Don't interpret exit_info for nested guests */ >> + svm_complete_interrupts(svm); >> + } >> >> if (npt_enabled) { >> int mmu_reload = 0; >> @@ -2602,8 +2614,6 @@ static void svm_complete_interrupts(struct >> vcpu_svm *svm) >> case SVM_EXITINTINFO_TYPE_EXEPT: >> /* In case of software exception do not reinject an exception >> vector, but re-execute and instruction instead */ >> - if (is_nested(svm)) >> - break; >> if (kvm_exception_is_soft(vector)) >> break; >> if (exitintinfo & SVM_EXITINTINFO_VALID_ERR) { >> -- >> 1.6.0.2 >> >> -- >> To unsubscribe from this list: send the line "unsubscribe kvm" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html