From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751985Ab2GUHZN (ORCPT ); Sat, 21 Jul 2012 03:25:13 -0400 Received: from mout.web.de ([212.227.17.11]:61769 "EHLO mout.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751719Ab2GUHZM (ORCPT ); Sat, 21 Jul 2012 03:25:12 -0400 X-Greylist: delayed 325 seconds by postgrey-1.27 at vger.kernel.org; Sat, 21 Jul 2012 03:25:12 EDT Message-ID: <500A580D.1010301@web.de> Date: Sat, 21 Jul 2012 09:19:41 +0200 From: Jan Kiszka User-Agent: Mozilla/5.0 (X11; U; Linux i686 (x86_64); de; rv:1.8.1.12) Gecko/20080226 SUSE/2.0.0.12-1.1 Thunderbird/2.0.0.12 Mnenhy/0.7.5.666 MIME-Version: 1.0 To: Wen Congyang CC: kvm list , qemu-devel , "linux-kernel@vger.kernel.org" , Avi Kivity , "Daniel P. Berrange" , KAMEZAWA Hiroyuki , Gleb Natapov Subject: Re: [PATCH v7] kvm: notify host when the guest is panicked References: <500A565A.8080403@cn.fujitsu.com> In-Reply-To: <500A565A.8080403@cn.fujitsu.com> X-Enigmail-Version: 1.4.3 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig232B1F9952360E33B1AE00D9" X-Provags-ID: V02:K0:vJ6xR1VBX6k0mZWDz6a6n/aw60ZUodhl5UQ62pbncwT kAi7E0buBsjahHE2ZdKtJIHaRCTwmMSiyg7uvMRquABUNIK/qt p+l/tQISeWYgo0N3mo+WKi9sHuvxoXENjHiOlRzp1cmnJvTRTu ifWzS3kLfy2ME2WYekcB1djnYlYCxqhWyR6Sd+3kZ7ISHxu8Qk oN/VPAgZoBo0caBt7XHEA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig232B1F9952360E33B1AE00D9 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 2012-07-21 09:12, Wen Congyang wrote: > We can know the guest is panicked when the guest runs on xen. > But we do not have such feature on kvm. >=20 > Another purpose of this feature is: management app(for example: > libvirt) can do auto dump when the guest is panicked. If management > app does not do auto dump, the guest's user can do dump by hand if > he sees the guest is panicked. >=20 > We have three solutions to implement this feature: > 1. use vmcall > 2. use I/O port > 3. use virtio-serial. >=20 > We have decided to avoid touching hypervisor. The reason why I choose > choose the I/O port is: > 1. it is easier to implememt > 2. it does not depend any virtual device > 3. it can work when startint the kernel >=20 > Signed-off-by: Wen Congyang > --- > arch/ia64/include/asm/kvm_para.h | 5 +++++ > arch/powerpc/include/asm/kvm_para.h | 5 +++++ > arch/s390/include/asm/kvm_para.h | 5 +++++ > arch/x86/include/asm/kvm_para.h | 7 +++++++ > arch/x86/kernel/kvm.c | 14 ++++++++++++++ > include/linux/kvm_para.h | 13 +++++++++++++ > 6 files changed, 49 insertions(+), 0 deletions(-) >=20 > diff --git a/arch/ia64/include/asm/kvm_para.h b/arch/ia64/include/asm/k= vm_para.h > index 2019cb9..187c0e2 100644 > --- a/arch/ia64/include/asm/kvm_para.h > +++ b/arch/ia64/include/asm/kvm_para.h > @@ -31,6 +31,11 @@ static inline bool kvm_check_and_clear_guest_paused(= void) > return false; > } > =20 > +static inline unsigned int kvm_arch_pv_features(void) > +{ > + return 0; > +} > + > #endif > =20 > #endif > diff --git a/arch/powerpc/include/asm/kvm_para.h b/arch/powerpc/include= /asm/kvm_para.h > index c18916b..be81aac 100644 > --- a/arch/powerpc/include/asm/kvm_para.h > +++ b/arch/powerpc/include/asm/kvm_para.h > @@ -211,6 +211,11 @@ static inline bool kvm_check_and_clear_guest_pause= d(void) > return false; > } > =20 > +static inline unsigned int kvm_arch_pv_features(void) > +{ > + return 0; > +} > + > #endif /* __KERNEL__ */ > =20 > #endif /* __POWERPC_KVM_PARA_H__ */ > diff --git a/arch/s390/include/asm/kvm_para.h b/arch/s390/include/asm/k= vm_para.h > index a988329..3d993b7 100644 > --- a/arch/s390/include/asm/kvm_para.h > +++ b/arch/s390/include/asm/kvm_para.h > @@ -154,6 +154,11 @@ static inline bool kvm_check_and_clear_guest_pause= d(void) > return false; > } > =20 > +static inline unsigned int kvm_arch_pv_features(void) > +{ > + return 0; > +} > + > #endif > =20 > #endif /* __S390_KVM_PARA_H */ > diff --git a/arch/x86/include/asm/kvm_para.h b/arch/x86/include/asm/kvm= _para.h > index 63ab166..c8ad86e 100644 > --- a/arch/x86/include/asm/kvm_para.h > +++ b/arch/x86/include/asm/kvm_para.h > @@ -89,6 +89,8 @@ struct kvm_vcpu_pv_apf_data { > __u32 enabled; > }; > =20 > +#define KVM_PV_PORT (0x505UL) > + > #ifdef __KERNEL__ > #include > =20 > @@ -221,6 +223,11 @@ static inline void kvm_disable_steal_time(void) > } > #endif > =20 > +static inline unsigned int kvm_arch_pv_features(void) > +{ > + return inl(KVM_PV_PORT); > +} > + > #endif /* __KERNEL__ */ > =20 > #endif /* _ASM_X86_KVM_PARA_H */ > diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c > index e554e5a..9a97f7e 100644 > --- a/arch/x86/kernel/kvm.c > +++ b/arch/x86/kernel/kvm.c > @@ -328,6 +328,17 @@ static struct notifier_block kvm_pv_reboot_nb =3D = { > .notifier_call =3D kvm_pv_reboot_notify, > }; > =20 > +static int > +kvm_pv_panic_notify(struct notifier_block *nb, unsigned long code, voi= d *unused) > +{ > + outl(KVM_PV_PANICKED, KVM_PV_PORT); > + return NOTIFY_DONE; > +} > + > +static struct notifier_block kvm_pv_panic_nb =3D { > + .notifier_call =3D kvm_pv_panic_notify, > +}; > + > static u64 kvm_steal_clock(int cpu) > { > u64 steal; > @@ -414,6 +425,9 @@ void __init kvm_guest_init(void) > =20 > paravirt_ops_setup(); > register_reboot_notifier(&kvm_pv_reboot_nb); > + if (kvm_pv_has_feature(KVM_PV_FEATURE_PANICKED)) > + atomic_notifier_chain_register(&panic_notifier_list, > + &kvm_pv_panic_nb); > for (i =3D 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/include/linux/kvm_para.h b/include/linux/kvm_para.h > index ff476dd..e73efcf 100644 > --- a/include/linux/kvm_para.h > +++ b/include/linux/kvm_para.h > @@ -20,6 +20,12 @@ > #define KVM_HC_FEATURES 3 > #define KVM_HC_PPC_MAP_MAGIC_PAGE 4 > =20 > +/* The bit of the value read from KVM_PV_PORT */ > +#define KVM_PV_FEATURE_PANICKED 0 > + > +/* The value writen to KVM_PV_PORT */ > +#define KVM_PV_PANICKED 1 > + > /* > * hypercalls use architecture specific > */ > @@ -33,5 +39,12 @@ static inline int kvm_para_has_feature(unsigned int = feature) > return 1; > return 0; > } > + > +static inline int kvm_pv_has_feature(unsigned int feature) > +{ > + if (kvm_arch_pv_features() & (1UL << feature)) Reading from an invalid I/O port will return -1. So your test will deliver a wrong result on a platform that doesn't support this PV channel= =2E Jan > + return 1; > + return 0; > +} > #endif /* __KERNEL__ */ > #endif /* __LINUX_KVM_PARA_H */ >=20 --------------enig232B1F9952360E33B1AE00D9 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.16 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAlAKWA0ACgkQitSsb3rl5xThvQCffQjfmpBHXT83smD0FOH31WM2 7TwAnjsvqFODU0wCi4LL/VUm8rV0e4jF =XfGT -----END PGP SIGNATURE----- --------------enig232B1F9952360E33B1AE00D9--