From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: [PATCH v2] KVM: x86: Extend KVM_SET_VCPU_EVENTS with selective updates Date: Sun, 06 Dec 2009 18:24:15 +0100 Message-ID: <4B1BE8BF.7030404@web.de> References: <4B1BE216.2090407@web.de> <4B1BE452.6090107@redhat.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig345DB8416178A92955DB0B85" Cc: Marcelo Tosatti , kvm , Gleb Natapov To: Avi Kivity Return-path: Received: from fmmailgate03.web.de ([217.72.192.234]:33278 "EHLO fmmailgate03.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933963AbZLFRYK (ORCPT ); Sun, 6 Dec 2009 12:24:10 -0500 In-Reply-To: <4B1BE452.6090107@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig345DB8416178A92955DB0B85 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: quoted-printable User space may not want to overwrite asynchronously changing VCPU event states on write-back. So allow to skip nmi.pending and sipi_vector by setting corresponding bits in the flags field of kvm_vcpu_events. Signed-off-by: Jan Kiszka --- Changes in v2: - invert selection logic Documentation/kvm/api.txt | 10 +++++++++- arch/x86/include/asm/kvm.h | 4 ++++ arch/x86/kvm/x86.c | 9 ++++++--- 3 files changed, 19 insertions(+), 4 deletions(-) diff --git a/Documentation/kvm/api.txt b/Documentation/kvm/api.txt index e1a1141..b22592d 100644 --- a/Documentation/kvm/api.txt +++ b/Documentation/kvm/api.txt @@ -685,7 +685,7 @@ struct kvm_vcpu_events { __u8 pad; } nmi; __u32 sipi_vector; - __u32 flags; /* must be zero */ + __u32 flags; }; =20 4.30 KVM_SET_VCPU_EVENTS @@ -701,6 +701,14 @@ vcpu. =20 See KVM_GET_VCPU_EVENTS for the data structure. =20 +Fields that may be modified asynchronously by running VCPUs can be exclu= ded +from the update. These fields are nmi.pending and sipi_vector. Keep the +corresponding bits in the flags field cleared to suppress overwriting th= e +current in-kernel state. The bits are: + +KVM_VCPUEVENT_SET_NMI_PENDING - transfer nmi.pending to the kernel +KVM_VCPUEVENT_SET_SIPI_VECTOR - transfer sipi_vector + =20 5. The kvm_run structure =20 diff --git a/arch/x86/include/asm/kvm.h b/arch/x86/include/asm/kvm.h index 950df43..d1a67ae 100644 --- a/arch/x86/include/asm/kvm.h +++ b/arch/x86/include/asm/kvm.h @@ -254,6 +254,10 @@ struct kvm_reinject_control { __u8 reserved[31]; }; =20 +/* When set in flags, include corresponding fields on KVM_SET_VCPU_EVENT= S */ +#define KVM_VCPUEVENT_SET_NMI_PENDING 0x00000001 +#define KVM_VCPUEVENT_SET_SIPI_VECTOR 0x00000002 + /* for KVM_GET/SET_VCPU_EVENTS */ struct kvm_vcpu_events { struct { diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index dd15d7a..e3c35ff 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1953,7 +1953,8 @@ static void kvm_vcpu_ioctl_x86_get_vcpu_events(stru= ct kvm_vcpu *vcpu, static int kvm_vcpu_ioctl_x86_set_vcpu_events(struct kvm_vcpu *vcpu, struct kvm_vcpu_events *events) { - if (events->flags) + if (events->flags & + ~(KVM_VCPUEVENT_SET_NMI_PENDING | KVM_VCPUEVENT_SET_SIPI_VECTOR)) return -EINVAL; =20 vcpu_load(vcpu); @@ -1970,10 +1971,12 @@ static int kvm_vcpu_ioctl_x86_set_vcpu_events(str= uct kvm_vcpu *vcpu, kvm_pic_clear_isr_ack(vcpu->kvm); =20 vcpu->arch.nmi_injected =3D events->nmi.injected; - vcpu->arch.nmi_pending =3D events->nmi.pending; + if (events->flags & KVM_VCPUEVENT_SET_NMI_PENDING) + vcpu->arch.nmi_pending =3D events->nmi.pending; kvm_x86_ops->set_nmi_mask(vcpu, events->nmi.masked); =20 - vcpu->arch.sipi_vector =3D events->sipi_vector; + if (events->flags & KVM_VCPUEVENT_SET_SIPI_VECTOR) + vcpu->arch.sipi_vector =3D events->sipi_vector; =20 vcpu_put(vcpu); =20 --------------enig345DB8416178A92955DB0B85 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org iEYEARECAAYFAksb6L8ACgkQitSsb3rl5xShdgCgxwZUDCnbSFqXawt9399YXkkY Jm0AoOHW6agd/Cc52Aaqb5OClVLmShK5 =QQPY -----END PGP SIGNATURE----- --------------enig345DB8416178A92955DB0B85--