Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756604Ab2B1IGo (ORCPT ); Tue, 28 Feb 2012 03:06:44 -0500 Received: from cn.fujitsu.com ([222.73.24.84]:56378 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1755026Ab2B1IGm (ORCPT ); Tue, 28 Feb 2012 03:06:42 -0500 Message-ID: <4F4C8B4D.5050704@cn.fujitsu.com> Date: Tue, 28 Feb 2012 16:07:41 +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> <4F4C6596.8020903@cn.fujitsu.com> In-Reply-To: <4F4C6596.8020903@cn.fujitsu.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2012-02-28 16:04:48, Serialize by Router on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2012-02-28 16:04:53, Serialize complete at 2012-02-28 16:04:53 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: 6531 Lines: 204 At 02/28/2012 01:26 PM, Wen Congyang Wrote: > 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 Sorry for my miss. kvm_emulate_hypercall() does not 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/ > -- 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/