From: Cornelia Huck <cohuck@redhat.com> To: David Gibson <david@gibson.dropbear.id.au> Cc: dgilbert@redhat.com, frankja@linux.ibm.com, pair@us.ibm.com, qemu-devel@nongnu.org, pbonzini@redhat.com, brijesh.singh@amd.com, ehabkost@redhat.com, marcel.apfelbaum@gmail.com, "Michael S. Tsirkin" <mst@redhat.com>, qemu-ppc@nongnu.org, kvm@vger.kernel.org, pasic@linux.ibm.com, qemu-s390x@nongnu.org, "David Hildenbrand" <david@redhat.com>, "Christian Borntraeger" <borntraeger@de.ibm.com>, "Richard Henderson" <rth@twiddle.net>, "Daniel P. Berrangé" <berrange@redhat.com>, mdroth@linux.vnet.ibm.com, "Thomas Huth" <thuth@redhat.com> Subject: Re: [for-5.2 v4 10/10] s390: Recognize host-trust-limitation option Date: Mon, 27 Jul 2020 17:50:40 +0200 [thread overview] Message-ID: <20200727175040.7beca3dd.cohuck@redhat.com> (raw) In-Reply-To: <20200724025744.69644-11-david@gibson.dropbear.id.au> On Fri, 24 Jul 2020 12:57:44 +1000 David Gibson <david@gibson.dropbear.id.au> wrote: > At least some s390 cpu models support "Protected Virtualization" (PV), > a mechanism to protect guests from eavesdropping by a compromised > hypervisor. > > This is similar in function to other mechanisms like AMD's SEV and > POWER's PEF, which are controlled bythe "host-trust-limitation" > machine option. s390 is a slightly special case, because we already > supported PV, simply by using a CPU model with the required feature > (S390_FEAT_UNPACK). > > To integrate this with the option used by other platforms, we > implement the following compromise: > > - When the host-trust-limitation option is set, s390 will recognize > it, verify that the CPU can support PV (failing if not) and set > virtio default options necessary for encrypted or protected guests, > as on other platforms. i.e. if host-trust-limitation is set, we > will either create a guest capable of entering PV mode, or fail > outright > > - If host-trust-limitation is not set, guest's might still be able to > enter PV mode, if the CPU has the right model. This may be a > little surprising, but shouldn't actually be harmful. This could be workable, I guess. Would like a second opinion, though. > > To start a guest supporting Protected Virtualization using the new > option use the command line arguments: > -object s390-pv-guest,id=pv0 -machine host-trust-limitation=pv0 > > Signed-off-by: David Gibson <david@gibson.dropbear.id.au> > --- > hw/s390x/pv.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 61 insertions(+) > > diff --git a/hw/s390x/pv.c b/hw/s390x/pv.c > index ab3a2482aa..4bf3b345b6 100644 > --- a/hw/s390x/pv.c > +++ b/hw/s390x/pv.c > @@ -14,8 +14,11 @@ > #include <linux/kvm.h> > > #include "cpu.h" > +#include "qapi/error.h" > #include "qemu/error-report.h" > #include "sysemu/kvm.h" > +#include "qom/object_interfaces.h" > +#include "exec/host-trust-limitation.h" > #include "hw/s390x/ipl.h" > #include "hw/s390x/pv.h" > > @@ -111,3 +114,61 @@ void s390_pv_inject_reset_error(CPUState *cs) > /* Report that we are unable to enter protected mode */ > env->regs[r1 + 1] = DIAG_308_RC_INVAL_FOR_PV; > } > + > +#define TYPE_S390_PV_GUEST "s390-pv-guest" > +#define S390_PV_GUEST(obj) \ > + OBJECT_CHECK(S390PVGuestState, (obj), TYPE_S390_PV_GUEST) > + > +typedef struct S390PVGuestState S390PVGuestState; > + > +/** > + * S390PVGuestState: > + * > + * The S390PVGuestState object is basically a dummy used to tell the > + * host trust limitation system to use s390's PV mechanism. guest. > + * > + * # $QEMU \ > + * -object s390-pv-guest,id=pv0 \ > + * -machine ...,host-trust-limitation=pv0 > + */ > +struct S390PVGuestState { > + Object parent_obj; > +}; > + > +static int s390_pv_kvm_init(HostTrustLimitation *gmpo, Error **errp) > +{ > + if (!s390_has_feat(S390_FEAT_UNPACK)) { > + error_setg(errp, > + "CPU model does not support Protected Virtualization"); > + return -1; > + } > + > + return 0; > +} So here's where I'm confused: If I follow the code correctly, the ->kvm_init callback is invoked before kvm_arch_init() is called. The kvm_arch_init() implementation for s390x checks whether KVM_CAP_S390_PROTECTED is available, which is a pre-req for S390_FEAT_UNPACK. Am I missing something? Can someone with access to PV hardware check whether this works as intended? > + > +static void s390_pv_guest_class_init(ObjectClass *oc, void *data) > +{ > + HostTrustLimitationClass *gmpc = HOST_TRUST_LIMITATION_CLASS(oc); > + > + gmpc->kvm_init = s390_pv_kvm_init; > +} > + > +static const TypeInfo s390_pv_guest_info = { > + .parent = TYPE_OBJECT, > + .name = TYPE_S390_PV_GUEST, > + .instance_size = sizeof(S390PVGuestState), > + .class_init = s390_pv_guest_class_init, > + .interfaces = (InterfaceInfo[]) { > + { TYPE_HOST_TRUST_LIMITATION }, > + { TYPE_USER_CREATABLE }, > + { } > + } > +}; > + > +static void > +s390_pv_register_types(void) > +{ > + type_register_static(&s390_pv_guest_info); > +} > + > +type_init(s390_pv_register_types);
WARNING: multiple messages have this Message-ID (diff)
From: Cornelia Huck <cohuck@redhat.com> To: David Gibson <david@gibson.dropbear.id.au> Cc: pair@us.ibm.com, brijesh.singh@amd.com, frankja@linux.ibm.com, kvm@vger.kernel.org, "Michael S. Tsirkin" <mst@redhat.com>, "David Hildenbrand" <david@redhat.com>, qemu-devel@nongnu.org, dgilbert@redhat.com, pasic@linux.ibm.com, "Christian Borntraeger" <borntraeger@de.ibm.com>, qemu-s390x@nongnu.org, qemu-ppc@nongnu.org, "Daniel P. Berrangé" <berrange@redhat.com>, "Thomas Huth" <thuth@redhat.com>, pbonzini@redhat.com, "Richard Henderson" <rth@twiddle.net>, mdroth@linux.vnet.ibm.com, ehabkost@redhat.com Subject: Re: [for-5.2 v4 10/10] s390: Recognize host-trust-limitation option Date: Mon, 27 Jul 2020 17:50:40 +0200 [thread overview] Message-ID: <20200727175040.7beca3dd.cohuck@redhat.com> (raw) In-Reply-To: <20200724025744.69644-11-david@gibson.dropbear.id.au> On Fri, 24 Jul 2020 12:57:44 +1000 David Gibson <david@gibson.dropbear.id.au> wrote: > At least some s390 cpu models support "Protected Virtualization" (PV), > a mechanism to protect guests from eavesdropping by a compromised > hypervisor. > > This is similar in function to other mechanisms like AMD's SEV and > POWER's PEF, which are controlled bythe "host-trust-limitation" > machine option. s390 is a slightly special case, because we already > supported PV, simply by using a CPU model with the required feature > (S390_FEAT_UNPACK). > > To integrate this with the option used by other platforms, we > implement the following compromise: > > - When the host-trust-limitation option is set, s390 will recognize > it, verify that the CPU can support PV (failing if not) and set > virtio default options necessary for encrypted or protected guests, > as on other platforms. i.e. if host-trust-limitation is set, we > will either create a guest capable of entering PV mode, or fail > outright > > - If host-trust-limitation is not set, guest's might still be able to > enter PV mode, if the CPU has the right model. This may be a > little surprising, but shouldn't actually be harmful. This could be workable, I guess. Would like a second opinion, though. > > To start a guest supporting Protected Virtualization using the new > option use the command line arguments: > -object s390-pv-guest,id=pv0 -machine host-trust-limitation=pv0 > > Signed-off-by: David Gibson <david@gibson.dropbear.id.au> > --- > hw/s390x/pv.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 61 insertions(+) > > diff --git a/hw/s390x/pv.c b/hw/s390x/pv.c > index ab3a2482aa..4bf3b345b6 100644 > --- a/hw/s390x/pv.c > +++ b/hw/s390x/pv.c > @@ -14,8 +14,11 @@ > #include <linux/kvm.h> > > #include "cpu.h" > +#include "qapi/error.h" > #include "qemu/error-report.h" > #include "sysemu/kvm.h" > +#include "qom/object_interfaces.h" > +#include "exec/host-trust-limitation.h" > #include "hw/s390x/ipl.h" > #include "hw/s390x/pv.h" > > @@ -111,3 +114,61 @@ void s390_pv_inject_reset_error(CPUState *cs) > /* Report that we are unable to enter protected mode */ > env->regs[r1 + 1] = DIAG_308_RC_INVAL_FOR_PV; > } > + > +#define TYPE_S390_PV_GUEST "s390-pv-guest" > +#define S390_PV_GUEST(obj) \ > + OBJECT_CHECK(S390PVGuestState, (obj), TYPE_S390_PV_GUEST) > + > +typedef struct S390PVGuestState S390PVGuestState; > + > +/** > + * S390PVGuestState: > + * > + * The S390PVGuestState object is basically a dummy used to tell the > + * host trust limitation system to use s390's PV mechanism. guest. > + * > + * # $QEMU \ > + * -object s390-pv-guest,id=pv0 \ > + * -machine ...,host-trust-limitation=pv0 > + */ > +struct S390PVGuestState { > + Object parent_obj; > +}; > + > +static int s390_pv_kvm_init(HostTrustLimitation *gmpo, Error **errp) > +{ > + if (!s390_has_feat(S390_FEAT_UNPACK)) { > + error_setg(errp, > + "CPU model does not support Protected Virtualization"); > + return -1; > + } > + > + return 0; > +} So here's where I'm confused: If I follow the code correctly, the ->kvm_init callback is invoked before kvm_arch_init() is called. The kvm_arch_init() implementation for s390x checks whether KVM_CAP_S390_PROTECTED is available, which is a pre-req for S390_FEAT_UNPACK. Am I missing something? Can someone with access to PV hardware check whether this works as intended? > + > +static void s390_pv_guest_class_init(ObjectClass *oc, void *data) > +{ > + HostTrustLimitationClass *gmpc = HOST_TRUST_LIMITATION_CLASS(oc); > + > + gmpc->kvm_init = s390_pv_kvm_init; > +} > + > +static const TypeInfo s390_pv_guest_info = { > + .parent = TYPE_OBJECT, > + .name = TYPE_S390_PV_GUEST, > + .instance_size = sizeof(S390PVGuestState), > + .class_init = s390_pv_guest_class_init, > + .interfaces = (InterfaceInfo[]) { > + { TYPE_HOST_TRUST_LIMITATION }, > + { TYPE_USER_CREATABLE }, > + { } > + } > +}; > + > +static void > +s390_pv_register_types(void) > +{ > + type_register_static(&s390_pv_guest_info); > +} > + > +type_init(s390_pv_register_types);
next prev parent reply other threads:[~2020-07-27 15:51 UTC|newest] Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-07-24 2:57 [for-5.2 v4 00/10] Generalize memory encryption models David Gibson 2020-07-24 2:57 ` David Gibson 2020-07-24 2:57 ` [for-5.2 v4 01/10] host trust limitation: Introduce new host trust limitation interface David Gibson 2020-07-24 2:57 ` David Gibson 2020-07-24 2:57 ` [for-5.2 v4 02/10] host trust limitation: Handle memory encryption via interface David Gibson 2020-07-24 2:57 ` David Gibson 2020-07-24 2:57 ` [for-5.2 v4 03/10] host trust limitation: Move side effect out of machine_set_memory_encryption() David Gibson 2020-07-24 2:57 ` David Gibson 2020-07-24 2:57 ` [for-5.2 v4 04/10] host trust limitation: Rework the "memory-encryption" property David Gibson 2020-07-24 2:57 ` David Gibson 2020-07-24 2:57 ` [for-5.2 v4 05/10] host trust limitation: Decouple kvm_memcrypt_*() helpers from KVM David Gibson 2020-07-24 2:57 ` David Gibson 2020-07-24 2:57 ` [for-5.2 v4 06/10] host trust limitation: Add Error ** to HostTrustLimitation::kvm_init David Gibson 2020-07-24 2:57 ` David Gibson 2020-07-24 2:57 ` [for-5.2 v4 07/10] spapr: Add PEF based host trust limitation David Gibson 2020-07-24 2:57 ` David Gibson 2020-07-24 2:57 ` [for-5.2 v4 08/10] spapr: PEF: block migration David Gibson 2020-07-24 2:57 ` David Gibson 2020-07-27 15:01 ` Dr. David Alan Gilbert 2020-07-27 15:01 ` Dr. David Alan Gilbert 2020-07-24 2:57 ` [for-5.2 v4 09/10] host trust limitation: Alter virtio default properties for protected guests David Gibson 2020-07-24 2:57 ` David Gibson 2020-07-27 15:05 ` Dr. David Alan Gilbert 2020-07-27 15:05 ` Dr. David Alan Gilbert 2020-08-13 7:43 ` Greg Kurz 2020-08-13 7:43 ` Greg Kurz 2020-08-13 8:19 ` Greg Kurz 2020-08-13 8:19 ` Greg Kurz 2020-09-07 15:10 ` Halil Pasic 2020-09-07 15:10 ` Halil Pasic 2020-09-11 2:04 ` David Gibson 2020-09-11 2:04 ` David Gibson 2020-09-11 13:49 ` Halil Pasic 2020-09-11 13:49 ` Halil Pasic 2020-07-24 2:57 ` [for-5.2 v4 10/10] s390: Recognize host-trust-limitation option David Gibson 2020-07-24 2:57 ` David Gibson 2020-07-27 15:50 ` Cornelia Huck [this message] 2020-07-27 15:50 ` Cornelia Huck 2020-08-03 7:40 ` Janosch Frank 2020-08-03 7:40 ` Janosch Frank 2020-08-06 6:14 ` David Gibson 2020-08-06 6:14 ` David Gibson 2020-08-06 7:18 ` David Hildenbrand 2020-08-06 7:18 ` David Hildenbrand 2020-08-03 7:49 ` Janosch Frank 2020-08-03 7:49 ` Janosch Frank 2020-08-03 7:54 ` David Gibson 2020-08-03 7:54 ` David Gibson 2020-08-03 8:07 ` Janosch Frank 2020-08-03 8:07 ` Janosch Frank 2020-08-03 8:14 ` David Gibson 2020-08-03 8:14 ` David Gibson 2020-08-03 8:33 ` Cornelia Huck 2020-08-03 8:33 ` Cornelia Huck 2020-09-07 15:22 ` Halil Pasic 2020-09-07 15:22 ` Halil Pasic 2020-09-10 11:36 ` Cornelia Huck 2020-09-10 11:36 ` Cornelia Huck 2020-09-10 18:29 ` Halil Pasic 2020-09-10 18:29 ` Halil Pasic 2020-09-11 0:07 ` David Gibson 2020-09-11 0:07 ` David Gibson 2020-09-11 6:25 ` Greg Kurz 2020-09-11 6:25 ` Greg Kurz 2020-09-11 12:45 ` Halil Pasic 2020-09-11 12:45 ` Halil Pasic
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20200727175040.7beca3dd.cohuck@redhat.com \ --to=cohuck@redhat.com \ --cc=berrange@redhat.com \ --cc=borntraeger@de.ibm.com \ --cc=brijesh.singh@amd.com \ --cc=david@gibson.dropbear.id.au \ --cc=david@redhat.com \ --cc=dgilbert@redhat.com \ --cc=ehabkost@redhat.com \ --cc=frankja@linux.ibm.com \ --cc=kvm@vger.kernel.org \ --cc=marcel.apfelbaum@gmail.com \ --cc=mdroth@linux.vnet.ibm.com \ --cc=mst@redhat.com \ --cc=pair@us.ibm.com \ --cc=pasic@linux.ibm.com \ --cc=pbonzini@redhat.com \ --cc=qemu-devel@nongnu.org \ --cc=qemu-ppc@nongnu.org \ --cc=qemu-s390x@nongnu.org \ --cc=rth@twiddle.net \ --cc=thuth@redhat.com \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.