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Violators will be prosecuted for from ; Wed, 4 Sep 2019 08:33:50 +0100 Subject: Re: [PATCH] KVM: s390: Disallow invalid bits in kvm_valid_regs and kvm_dirty_regs References: <20190904071308.25683-1-thuth@redhat.com> From: Janosch Frank Date: Wed, 4 Sep 2019 09:33:45 +0200 MIME-Version: 1.0 In-Reply-To: <20190904071308.25683-1-thuth@redhat.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="KCJXWAnzrD8uRwAanjK8DKax8UhWoz0bJ" Message-Id: <3b1666ee-0b7f-a775-3622-5ca7f938aeb0@linux.ibm.com> Sender: linux-s390-owner@vger.kernel.org List-ID: To: Thomas Huth , kvm@vger.kernel.org, Christian Borntraeger Cc: David Hildenbrand , Cornelia Huck , linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --KCJXWAnzrD8uRwAanjK8DKax8UhWoz0bJ Content-Type: multipart/mixed; boundary="xPn7lGCZnSVGl0FJB37AXdkF6Z4YI95iy"; protected-headers="v1" From: Janosch Frank To: Thomas Huth , kvm@vger.kernel.org, Christian Borntraeger Cc: David Hildenbrand , Cornelia Huck , linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org Message-ID: <3b1666ee-0b7f-a775-3622-5ca7f938aeb0@linux.ibm.com> Subject: Re: [PATCH] KVM: s390: Disallow invalid bits in kvm_valid_regs and kvm_dirty_regs References: <20190904071308.25683-1-thuth@redhat.com> In-Reply-To: <20190904071308.25683-1-thuth@redhat.com> --xPn7lGCZnSVGl0FJB37AXdkF6Z4YI95iy Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 9/4/19 9:13 AM, Thomas Huth wrote: > If unknown bits are set in kvm_valid_regs or kvm_dirty_regs, this > clearly indicates that something went wrong in the KVM userspace > application. The x86 variant of KVM already contains a check for > bad bits (and the corresponding kselftest checks this), so let's > do the same on s390x now, too. >=20 > Signed-off-by: Thomas Huth I think it would make sense to split the kvm changes from the test. Reviewed-by: Janosch Frank > --- > arch/s390/include/uapi/asm/kvm.h | 6 ++++ > arch/s390/kvm/kvm-s390.c | 4 +++ > .../selftests/kvm/s390x/sync_regs_test.c | 30 +++++++++++++++++++= > 3 files changed, 40 insertions(+) >=20 > diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/= asm/kvm.h > index 47104e5b47fd..436ec7636927 100644 > --- a/arch/s390/include/uapi/asm/kvm.h > +++ b/arch/s390/include/uapi/asm/kvm.h > @@ -231,6 +231,12 @@ struct kvm_guest_debug_arch { > #define KVM_SYNC_GSCB (1UL << 9) > #define KVM_SYNC_BPBC (1UL << 10) > #define KVM_SYNC_ETOKEN (1UL << 11) > + > +#define KVM_SYNC_S390_VALID_FIELDS \ > + (KVM_SYNC_PREFIX | KVM_SYNC_GPRS | KVM_SYNC_ACRS | KVM_SYNC_CRS | \ > + KVM_SYNC_ARCH0 | KVM_SYNC_PFAULT | KVM_SYNC_VRS | KVM_SYNC_RICCB | \= > + KVM_SYNC_FPRS | KVM_SYNC_GSCB | KVM_SYNC_BPBC | KVM_SYNC_ETOKEN) > + > /* length and alignment of the sdnx as a power of two */ > #define SDNXC 8 > #define SDNXL (1UL << SDNXC) > diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c > index 49d7722229ae..a7d7dedfe527 100644 > --- a/arch/s390/kvm/kvm-s390.c > +++ b/arch/s390/kvm/kvm-s390.c > @@ -3998,6 +3998,10 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcp= u, struct kvm_run *kvm_run) > if (kvm_run->immediate_exit) > return -EINTR; > =20 > + if (kvm_run->kvm_valid_regs & ~KVM_SYNC_S390_VALID_FIELDS || > + kvm_run->kvm_dirty_regs & ~KVM_SYNC_S390_VALID_FIELDS) > + return -EINVAL; > + > vcpu_load(vcpu); > =20 > if (guestdbg_exit_pending(vcpu)) { > diff --git a/tools/testing/selftests/kvm/s390x/sync_regs_test.c b/tools= /testing/selftests/kvm/s390x/sync_regs_test.c > index bbc93094519b..d5290b4ad636 100644 > --- a/tools/testing/selftests/kvm/s390x/sync_regs_test.c > +++ b/tools/testing/selftests/kvm/s390x/sync_regs_test.c > @@ -85,6 +85,36 @@ int main(int argc, char *argv[]) > =20 > run =3D vcpu_state(vm, VCPU_ID); > =20 > + /* Request reading invalid register set from VCPU. */ > + run->kvm_valid_regs =3D INVALID_SYNC_FIELD; > + rv =3D _vcpu_run(vm, VCPU_ID); > + TEST_ASSERT(rv < 0 && errno =3D=3D EINVAL, > + "Invalid kvm_valid_regs did not cause expected KVM_RUN error: %d= \n", > + rv); > + vcpu_state(vm, VCPU_ID)->kvm_valid_regs =3D 0; > + > + run->kvm_valid_regs =3D INVALID_SYNC_FIELD | TEST_SYNC_FIELDS; > + rv =3D _vcpu_run(vm, VCPU_ID); > + TEST_ASSERT(rv < 0 && errno =3D=3D EINVAL, > + "Invalid kvm_valid_regs did not cause expected KVM_RUN error: %d= \n", > + rv); > + vcpu_state(vm, VCPU_ID)->kvm_valid_regs =3D 0; > + > + /* Request setting invalid register set into VCPU. */ > + run->kvm_dirty_regs =3D INVALID_SYNC_FIELD; > + rv =3D _vcpu_run(vm, VCPU_ID); > + TEST_ASSERT(rv < 0 && errno =3D=3D EINVAL, > + "Invalid kvm_dirty_regs did not cause expected KVM_RUN error: %d= \n", > + rv); > + vcpu_state(vm, VCPU_ID)->kvm_dirty_regs =3D 0; > + > + run->kvm_dirty_regs =3D INVALID_SYNC_FIELD | TEST_SYNC_FIELDS; > + rv =3D _vcpu_run(vm, VCPU_ID); > + TEST_ASSERT(rv < 0 && errno =3D=3D EINVAL, > + "Invalid kvm_dirty_regs did not cause expected KVM_RUN error: %d= \n", > + rv); > + vcpu_state(vm, VCPU_ID)->kvm_dirty_regs =3D 0; > + > /* Request and verify all valid register sets. */ > run->kvm_valid_regs =3D TEST_SYNC_FIELDS; > rv =3D _vcpu_run(vm, VCPU_ID); >=20 --xPn7lGCZnSVGl0FJB37AXdkF6Z4YI95iy-- --KCJXWAnzrD8uRwAanjK8DKax8UhWoz0bJ Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEwGNS88vfc9+v45Yq41TmuOI4ufgFAl1vaNoACgkQ41TmuOI4 ufjW5xAAqrwQio0Wlchvkb6AmqBKX2hwY0bGnw4oALIkbpoEMQIKLp1Ka88r55wt cZAk90yeT7AMHNpeerBsMqkXRn5FhWkCdGGcowmjPNLHImCCwq8YztzNmps+yvxR S25XUoTODXHPXZFVxUyvLsA2wQPuKuo1nt9jvT9Ecbfoi4IFs/Hr/9+cIBWb4Dx4 Cci6QnW/dLpEkgZ195hgZOif+ENGbd7fod5y73zkCI/sVrUPWyhM/di3afS2pDOZ 7+Ckf9ydQDbGP1dfEPK5tsi/bYmKpHHqH5ORhemKJRGgBjaLqEPBq5pzxvYkVM50 TPP3SpukZmDHzFX7VvIWMuGApyxE+IEC3+u2zGBabZTE+hMIAlRDrW6LplmV42dt ZyhPr9tJCYRLiMdzBZLzL1lBPm9EqbBhV47/WM66iu7256ljJ03eN6KeBlBOT8PC KdpR7LmyB5EoNTYMZ6XgBmBefFKb/JTcigTtIaXNXIOrlbVT2kreYpp2KIN/lwif DAFiTJptZX9W+tIBV6A0b9SXQBeovLiDCBjMlSZy08Edm18dr5TVeUbhoQGtpYyY 7/jf6WVewzjn4YO/1hX2a1uL5dkCDLoIhx18IuQ+V7MPlbELoYZQuB7+P074xR7e UiQmR8/qS29kOKEpaMx75rk9N2BRmyahWRjo7mCbjsNC0mB479Q= =bXog -----END PGP SIGNATURE----- --KCJXWAnzrD8uRwAanjK8DKax8UhWoz0bJ--