Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753382Ab2B1FZs (ORCPT ); Tue, 28 Feb 2012 00:25:48 -0500 Received: from cn.fujitsu.com ([222.73.24.84]:55939 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751098Ab2B1FZq (ORCPT ); Tue, 28 Feb 2012 00:25:46 -0500 Message-ID: <4F4C6596.8020903@cn.fujitsu.com> Date: Tue, 28 Feb 2012 13:26:46 +0800 From: Wen Congyang User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100413 Fedora/3.0.4-2.fc13 Thunderbird/3.0.4 MIME-Version: 1.0 To: Jan Kiszka CC: kvm list , Avi Kivity , KAMEZAWA Hiroyuki , "Daniel P. Berrange" , linux-kernel@vger.kernel.org, qemu-devel Subject: Re: [PATCH] kvm: notify host when guest paniced References: <4F4AF1FB.6000903@cn.fujitsu.com> <4F4B9C57.3010407@siemens.com> In-Reply-To: <4F4B9C57.3010407@siemens.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2012-02-28 13:23:55, Serialize by Router on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2012-02-28 13:23:57, Serialize complete at 2012-02-28 13:23:57 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5956 Lines: 193 At 02/27/2012 11:08 PM, Jan Kiszka Wrote: > On 2012-02-27 04:01, Wen Congyang wrote: >> We can know the guest is paniced when the guest runs on xen. >> But we do not have such feature on kvm. This patch implemnts >> this feature, and the implementation is the same as xen: >> register panic notifier, and call hypercall when the guest >> is paniced. >> >> Signed-off-by: Wen Congyang >> --- >> arch/x86/kernel/kvm.c | 12 ++++++++++++ >> arch/x86/kvm/svm.c | 8 ++++++-- >> arch/x86/kvm/vmx.c | 8 ++++++-- >> arch/x86/kvm/x86.c | 13 +++++++++++-- >> include/linux/kvm.h | 1 + >> include/linux/kvm_para.h | 1 + >> 6 files changed, 37 insertions(+), 6 deletions(-) >> >> diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c >> index f0c6fd6..b928d1d 100644 >> --- a/arch/x86/kernel/kvm.c >> +++ b/arch/x86/kernel/kvm.c >> @@ -331,6 +331,17 @@ static struct notifier_block kvm_pv_reboot_nb = { >> .notifier_call = kvm_pv_reboot_notify, >> }; >> >> +static int >> +kvm_pv_panic_notify(struct notifier_block *nb, unsigned long code, void *unused) >> +{ >> + kvm_hypercall0(KVM_HC_GUEST_PANIC); >> + return NOTIFY_DONE; >> +} >> + >> +static struct notifier_block kvm_pv_panic_nb = { >> + .notifier_call = kvm_pv_panic_notify, >> +}; >> + > > You should split up host and guest-side changes. OK > >> static u64 kvm_steal_clock(int cpu) >> { >> u64 steal; >> @@ -417,6 +428,7 @@ void __init kvm_guest_init(void) >> >> paravirt_ops_setup(); >> register_reboot_notifier(&kvm_pv_reboot_nb); >> + atomic_notifier_chain_register(&panic_notifier_list, &kvm_pv_panic_nb); >> for (i = 0; i < KVM_TASK_SLEEP_HASHSIZE; i++) >> spin_lock_init(&async_pf_sleepers[i].lock); >> if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF)) >> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c >> index 0b7690e..38b4705 100644 >> --- a/arch/x86/kvm/svm.c >> +++ b/arch/x86/kvm/svm.c >> @@ -1900,10 +1900,14 @@ static int halt_interception(struct vcpu_svm *svm) >> >> static int vmmcall_interception(struct vcpu_svm *svm) >> { >> + int ret; >> + >> svm->next_rip = kvm_rip_read(&svm->vcpu) + 3; >> skip_emulated_instruction(&svm->vcpu); >> - kvm_emulate_hypercall(&svm->vcpu); >> - return 1; >> + ret = kvm_emulate_hypercall(&svm->vcpu); >> + >> + /* Ignore the error? */ >> + return ret == 0 ? 0 : 1; > > Why can't kvm_emulate_hypercall return the right value? Because before this patch, kvm always ignores the error. After rereading the code, kvm_emulate_hypercall() will return -KVM_EPERM when vcpu's CPL is not 0. I think we should deal with this exception in kvm_emulate_hypercall(), and return 1. But I donot know how to do it. kvm_queue_exception(vcpu, UD_VECTOR)? > >> } >> >> static unsigned long nested_svm_get_tdp_cr3(struct kvm_vcpu *vcpu) >> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c >> index 66147ca..1b57ebb 100644 >> --- a/arch/x86/kvm/vmx.c >> +++ b/arch/x86/kvm/vmx.c >> @@ -4582,9 +4582,13 @@ static int handle_halt(struct kvm_vcpu *vcpu) >> >> static int handle_vmcall(struct kvm_vcpu *vcpu) >> { >> + int ret; >> + >> skip_emulated_instruction(vcpu); >> - kvm_emulate_hypercall(vcpu); >> - return 1; >> + ret = kvm_emulate_hypercall(vcpu); >> + >> + /* Ignore the error? */ >> + return ret == 0 ? 0 : 1; >> } >> >> static int handle_invd(struct kvm_vcpu *vcpu) >> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c >> index c9d99e5..3fc2853 100644 >> --- a/arch/x86/kvm/x86.c >> +++ b/arch/x86/kvm/x86.c >> @@ -4923,7 +4923,7 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu) >> u64 param, ingpa, outgpa, ret; >> uint16_t code, rep_idx, rep_cnt, res = HV_STATUS_SUCCESS, rep_done = 0; >> bool fast, longmode; >> - int cs_db, cs_l; >> + int cs_db, cs_l, r = 1; >> >> /* >> * hypercall generates UD from non zero cpl and real mode >> @@ -4964,6 +4964,10 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu) >> case HV_X64_HV_NOTIFY_LONG_SPIN_WAIT: >> kvm_vcpu_on_spin(vcpu); >> break; >> + case KVM_HC_GUEST_PANIC: >> + vcpu->run->exit_reason = KVM_EXIT_GUEST_PANIC; >> + r = 0; >> + break; > > That's the wrong place. This is a KVM hypercall, not a HyperV one. OK, I will remove it. Thanks Wen Congyang > >> default: >> res = HV_STATUS_INVALID_HYPERCALL_CODE; >> break; >> @@ -4977,7 +4981,7 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu) >> kvm_register_write(vcpu, VCPU_REGS_RAX, ret & 0xffffffff); >> } >> >> - return 1; >> + return r; >> } >> >> int kvm_emulate_hypercall(struct kvm_vcpu *vcpu) >> @@ -5013,6 +5017,11 @@ int kvm_emulate_hypercall(struct kvm_vcpu *vcpu) >> case KVM_HC_VAPIC_POLL_IRQ: >> ret = 0; >> break; >> + case KVM_HC_GUEST_PANIC: >> + ret = 0; >> + vcpu->run->exit_reason = KVM_EXIT_GUEST_PANIC; >> + r = 0; >> + break; >> default: >> ret = -KVM_ENOSYS; >> break; >> diff --git a/include/linux/kvm.h b/include/linux/kvm.h >> index acbe429..8f0e31b 100644 >> --- a/include/linux/kvm.h >> +++ b/include/linux/kvm.h >> @@ -163,6 +163,7 @@ struct kvm_pit_config { >> #define KVM_EXIT_OSI 18 >> #define KVM_EXIT_PAPR_HCALL 19 >> #define KVM_EXIT_S390_UCONTROL 20 >> +#define KVM_EXIT_GUEST_PANIC 21 >> >> /* For KVM_EXIT_INTERNAL_ERROR */ >> #define KVM_INTERNAL_ERROR_EMULATION 1 >> diff --git a/include/linux/kvm_para.h b/include/linux/kvm_para.h >> index ff476dd..cf94023 100644 >> --- a/include/linux/kvm_para.h >> +++ b/include/linux/kvm_para.h >> @@ -19,6 +19,7 @@ >> #define KVM_HC_MMU_OP 2 >> #define KVM_HC_FEATURES 3 >> #define KVM_HC_PPC_MAP_MAGIC_PAGE 4 >> +#define KVM_HC_GUEST_PANIC 5 >> >> /* >> * hypercalls use architecture specific > > Jan > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/