| Message ID | 20210112044508.427338-11-david@gibson.dropbear.id.au (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Generalize memory encryption models | expand |
On 12.01.21 05:45, David Gibson wrote: [...] > diff --git a/include/hw/ppc/pef.h b/include/hw/ppc/pef.h > new file mode 100644 > index 0000000000..7c92391177 > --- /dev/null > +++ b/include/hw/ppc/pef.h > @@ -0,0 +1,26 @@ > +/* > + * PEF (Protected Execution Facility) for POWER support > + * > + * Copyright David Gibson, Redhat Inc. 2020 > + * > + * This work is licensed under the terms of the GNU GPL, version 2 or later. > + * See the COPYING file in the top-level directory. > + * > + */ > + > +#ifndef HW_PPC_PEF_H > +#define HW_PPC_PEF_H > + > +int pef_kvm_init(ConfidentialGuestSupport *cgs, Error **errp); > + > +#ifdef CONFIG_KVM > +void kvmppc_svm_off(Error **errp); > +#else > +static inline void kvmppc_svm_off(Error **errp) > +{ > +} > +#endif > + > + > +#endif /* HW_PPC_PEF_H */ > + In case you do a respin, git am says Applying: confidential guest support: Update documentation Applying: spapr: Add PEF based confidential guest support .git/rebase-apply/patch:254: new blank line at EOF. + warning: 1 line adds whitespace errors. Applying: spapr: PEF: prevent migration
On Tue, Jan 12, 2021 at 08:56:53AM +0100, Christian Borntraeger wrote: > > > On 12.01.21 05:45, David Gibson wrote: > [...] > > diff --git a/include/hw/ppc/pef.h b/include/hw/ppc/pef.h > > new file mode 100644 > > index 0000000000..7c92391177 > > --- /dev/null > > +++ b/include/hw/ppc/pef.h > > @@ -0,0 +1,26 @@ > > +/* > > + * PEF (Protected Execution Facility) for POWER support > > + * > > + * Copyright David Gibson, Redhat Inc. 2020 > > + * > > + * This work is licensed under the terms of the GNU GPL, version 2 or later. > > + * See the COPYING file in the top-level directory. > > + * > > + */ > > + > > +#ifndef HW_PPC_PEF_H > > +#define HW_PPC_PEF_H > > + > > +int pef_kvm_init(ConfidentialGuestSupport *cgs, Error **errp); > > + > > +#ifdef CONFIG_KVM > > +void kvmppc_svm_off(Error **errp); > > +#else > > +static inline void kvmppc_svm_off(Error **errp) > > +{ > > +} > > +#endif > > + > > + > > +#endif /* HW_PPC_PEF_H */ > > + > > In case you do a respin, > > git am says > Applying: confidential guest support: Update documentation > Applying: spapr: Add PEF based confidential guest support > .git/rebase-apply/patch:254: new blank line at EOF. > + > warning: 1 line adds whitespace errors. > Applying: spapr: PEF: prevent migration Oops, corrected.
On Tue, Jan 12, 2021 at 03:45:05PM +1100, David Gibson wrote: > Some upcoming POWER machines have a system called PEF (Protected > Execution Facility) which uses a small ultravisor to allow guests to > run in a way that they can't be eavesdropped by the hypervisor. The > effect is roughly similar to AMD SEV, although the mechanisms are > quite different. > > Most of the work of this is done between the guest, KVM and the > ultravisor, with little need for involvement by qemu. However qemu > does need to tell KVM to allow secure VMs. > > Because the availability of secure mode is a guest visible difference > which depends on having the right hardware and firmware, we don't > enable this by default. In order to run a secure guest you need to > create a "pef-guest" object and set the confidential-guest-support > property to point to it. > > Note that this just *allows* secure guests, the architecture of PEF is > such that the guest still needs to talk to the ultravisor to enter > secure mode. Qemu has no directl way of knowing if the guest is in > secure mode, and certainly can't know until well after machine > creation time. > > To start a PEF-capable guest, use the command line options: > -object pef-guest,id=pef0 -machine confidential-guest-support=pef0 > > Signed-off-by: David Gibson <david@gibson.dropbear.id.au> > --- > docs/confidential-guest-support.txt | 2 + > docs/papr-pef.txt | 30 ++++++++ > hw/ppc/meson.build | 1 + > hw/ppc/pef.c | 115 ++++++++++++++++++++++++++++ > hw/ppc/spapr.c | 10 +++ > include/hw/ppc/pef.h | 26 +++++++ > target/ppc/kvm.c | 18 ----- > target/ppc/kvm_ppc.h | 6 -- > 8 files changed, 184 insertions(+), 24 deletions(-) > create mode 100644 docs/papr-pef.txt > create mode 100644 hw/ppc/pef.c > create mode 100644 include/hw/ppc/pef.h > > diff --git a/hw/ppc/pef.c b/hw/ppc/pef.c > new file mode 100644 > index 0000000000..b227dc6905 > --- /dev/null > +++ b/hw/ppc/pef.c > @@ -0,0 +1,115 @@ > +/* > + * PEF (Protected Execution Facility) for POWER support > + * > + * Copyright David Gibson, Redhat Inc. 2020 > + * > + * This work is licensed under the terms of the GNU GPL, version 2 or later. > + * See the COPYING file in the top-level directory. > + * > + */ > + > +#include "qemu/osdep.h" > + > +#include "qapi/error.h" > +#include "qom/object_interfaces.h" > +#include "sysemu/kvm.h" > +#include "migration/blocker.h" > +#include "exec/confidential-guest-support.h" > +#include "hw/ppc/pef.h" > + > +#define TYPE_PEF_GUEST "pef-guest" > +#define PEF_GUEST(obj) \ > + OBJECT_CHECK(PefGuestState, (obj), TYPE_PEF_GUEST) > + > +typedef struct PefGuestState PefGuestState; Can use OBJECT_DECLARE_TYPE. Also the struct naming ought to match the type naming. eg use PefGuest for the struct, to match TYPE_PEF_GUEST. > + > +/** > + * PefGuestState: > + * > + * The PefGuestState object is used for creating and managing a PEF > + * guest. > + * > + * # $QEMU \ > + * -object pef-guest,id=pef0 \ > + * -machine ...,confidential-guest-support=pef0 > + */ > +struct PefGuestState { > + Object parent_obj; > +}; > + > +#ifdef CONFIG_KVM > +static int kvmppc_svm_init(Error **errp) > +{ > + if (!kvm_check_extension(kvm_state, KVM_CAP_PPC_SECURE_GUEST)) { > + error_setg(errp, > + "KVM implementation does not support Secure VMs (is an ultravisor running?)"); > + return -1; > + } else { > + int ret = kvm_vm_enable_cap(kvm_state, KVM_CAP_PPC_SECURE_GUEST, 0, 1); > + > + if (ret < 0) { > + error_setg(errp, > + "Error enabling PEF with KVM"); > + return -1; > + } > + } > + > + return 0; > +} > + > +/* > + * Don't set error if KVM_PPC_SVM_OFF ioctl is invoked on kernels > + * that don't support this ioctl. > + */ > +void kvmppc_svm_off(Error **errp) > +{ > + int rc; > + > + if (!kvm_enabled()) { > + return; > + } > + > + rc = kvm_vm_ioctl(KVM_STATE(current_accel()), KVM_PPC_SVM_OFF); > + if (rc && rc != -ENOTTY) { > + error_setg_errno(errp, -rc, "KVM_PPC_SVM_OFF ioctl failed"); > + } > +} > +#else > +static int kvmppc_svm_init(Error **errp) > +{ > + g_assert_not_reached(); > +} > +#endif > + > +int pef_kvm_init(ConfidentialGuestSupport *cgs, Error **errp) > +{ > + if (!object_dynamic_cast(OBJECT(cgs), TYPE_PEF_GUEST)) { > + return 0; > + } > + > + if (!kvm_enabled()) { > + error_setg(errp, "PEF requires KVM"); > + return -1; > + } > + > + return kvmppc_svm_init(errp); > +} > + > +static const TypeInfo pef_guest_info = { > + .parent = TYPE_OBJECT, > + .name = TYPE_PEF_GUEST, > + .instance_size = sizeof(PefGuestState), > + .interfaces = (InterfaceInfo[]) { > + { TYPE_CONFIDENTIAL_GUEST_SUPPORT }, > + { TYPE_USER_CREATABLE }, > + { } > + } > +}; > + > +static void > +pef_register_types(void) > +{ > + type_register_static(&pef_guest_info); > +} > + > +type_init(pef_register_types); Can use OBJECT_DEFINE_TYPE_WITH_INTERFACES here Regards, Daniel
On Tue, Jan 12, 2021 at 03:45:05PM +1100, David Gibson wrote: > Some upcoming POWER machines have a system called PEF (Protected > Execution Facility) which uses a small ultravisor to allow guests to > run in a way that they can't be eavesdropped by the hypervisor. The > effect is roughly similar to AMD SEV, although the mechanisms are > quite different. > > Most of the work of this is done between the guest, KVM and the > ultravisor, with little need for involvement by qemu. However qemu > does need to tell KVM to allow secure VMs. > > Because the availability of secure mode is a guest visible difference > which depends on having the right hardware and firmware, we don't > enable this by default. In order to run a secure guest you need to > create a "pef-guest" object and set the confidential-guest-support > property to point to it. > > Note that this just *allows* secure guests, the architecture of PEF is > such that the guest still needs to talk to the ultravisor to enter > secure mode. Qemu has no directl way of knowing if the guest is in > secure mode, and certainly can't know until well after machine > creation time. > > To start a PEF-capable guest, use the command line options: > -object pef-guest,id=pef0 -machine confidential-guest-support=pef0 > > Signed-off-by: David Gibson <david@gibson.dropbear.id.au> > --- > docs/confidential-guest-support.txt | 2 + > docs/papr-pef.txt | 30 ++++++++ > hw/ppc/meson.build | 1 + > hw/ppc/pef.c | 115 ++++++++++++++++++++++++++++ > hw/ppc/spapr.c | 10 +++ > include/hw/ppc/pef.h | 26 +++++++ > target/ppc/kvm.c | 18 ----- > target/ppc/kvm_ppc.h | 6 -- > 8 files changed, 184 insertions(+), 24 deletions(-) > create mode 100644 docs/papr-pef.txt > create mode 100644 hw/ppc/pef.c > create mode 100644 include/hw/ppc/pef.h > > +static const TypeInfo pef_guest_info = { > + .parent = TYPE_OBJECT, > + .name = TYPE_PEF_GUEST, > + .instance_size = sizeof(PefGuestState), > + .interfaces = (InterfaceInfo[]) { > + { TYPE_CONFIDENTIAL_GUEST_SUPPORT }, > + { TYPE_USER_CREATABLE }, > + { } > + } > +}; IIUC, the earlier patch defines TYPE_CONFIDENTIAL_GUEST_SUPPORT as a object, but you're using it as an interface here. The later s390 patch uses it as a parent, which makes more sense given it is a declared as an object. Regards, Daniel
On Tue, Jan 12, 2021 at 09:56:12AM +0000, Daniel P. Berrangé wrote: > On Tue, Jan 12, 2021 at 03:45:05PM +1100, David Gibson wrote: > > Some upcoming POWER machines have a system called PEF (Protected > > Execution Facility) which uses a small ultravisor to allow guests to > > run in a way that they can't be eavesdropped by the hypervisor. The > > effect is roughly similar to AMD SEV, although the mechanisms are > > quite different. > > > > Most of the work of this is done between the guest, KVM and the > > ultravisor, with little need for involvement by qemu. However qemu > > does need to tell KVM to allow secure VMs. > > > > Because the availability of secure mode is a guest visible difference > > which depends on having the right hardware and firmware, we don't > > enable this by default. In order to run a secure guest you need to > > create a "pef-guest" object and set the confidential-guest-support > > property to point to it. > > > > Note that this just *allows* secure guests, the architecture of PEF is > > such that the guest still needs to talk to the ultravisor to enter > > secure mode. Qemu has no directl way of knowing if the guest is in > > secure mode, and certainly can't know until well after machine > > creation time. > > > > To start a PEF-capable guest, use the command line options: > > -object pef-guest,id=pef0 -machine confidential-guest-support=pef0 > > > > Signed-off-by: David Gibson <david@gibson.dropbear.id.au> > > --- > > docs/confidential-guest-support.txt | 2 + > > docs/papr-pef.txt | 30 ++++++++ > > hw/ppc/meson.build | 1 + > > hw/ppc/pef.c | 115 ++++++++++++++++++++++++++++ > > hw/ppc/spapr.c | 10 +++ > > include/hw/ppc/pef.h | 26 +++++++ > > target/ppc/kvm.c | 18 ----- > > target/ppc/kvm_ppc.h | 6 -- > > 8 files changed, 184 insertions(+), 24 deletions(-) > > create mode 100644 docs/papr-pef.txt > > create mode 100644 hw/ppc/pef.c > > create mode 100644 include/hw/ppc/pef.h > > > > > +static const TypeInfo pef_guest_info = { > > + .parent = TYPE_OBJECT, > > + .name = TYPE_PEF_GUEST, > > + .instance_size = sizeof(PefGuestState), > > + .interfaces = (InterfaceInfo[]) { > > + { TYPE_CONFIDENTIAL_GUEST_SUPPORT }, > > + { TYPE_USER_CREATABLE }, > > + { } > > + } > > +}; > > IIUC, the earlier patch defines TYPE_CONFIDENTIAL_GUEST_SUPPORT > as a object, but you're using it as an interface here. The later > s390 patch uses it as a parent, which makes more sense given it > is a declared as an object. Oops, that's a holdover from an earlier version that used an interface. Fixed.
On Tue, Jan 12, 2021 at 12:27:50PM +0100, Greg Kurz wrote: > On Tue, 12 Jan 2021 15:45:05 +1100 > David Gibson <david@gibson.dropbear.id.au> wrote: > > > Some upcoming POWER machines have a system called PEF (Protected > > Execution Facility) which uses a small ultravisor to allow guests to > > run in a way that they can't be eavesdropped by the hypervisor. The > > effect is roughly similar to AMD SEV, although the mechanisms are > > quite different. > > > > Most of the work of this is done between the guest, KVM and the > > ultravisor, with little need for involvement by qemu. However qemu > > does need to tell KVM to allow secure VMs. > > > > Because the availability of secure mode is a guest visible difference > > which depends on having the right hardware and firmware, we don't > > enable this by default. In order to run a secure guest you need to > > create a "pef-guest" object and set the confidential-guest-support > > property to point to it. > > > > Note that this just *allows* secure guests, the architecture of PEF is > > such that the guest still needs to talk to the ultravisor to enter > > secure mode. Qemu has no directl way of knowing if the guest is in > > secure mode, and certainly can't know until well after machine > > creation time. > > > > To start a PEF-capable guest, use the command line options: > > -object pef-guest,id=pef0 -machine confidential-guest-support=pef0 > > > > Signed-off-by: David Gibson <david@gibson.dropbear.id.au> > > --- > > docs/confidential-guest-support.txt | 2 + > > docs/papr-pef.txt | 30 ++++++++ > > hw/ppc/meson.build | 1 + > > hw/ppc/pef.c | 115 ++++++++++++++++++++++++++++ > > hw/ppc/spapr.c | 10 +++ > > include/hw/ppc/pef.h | 26 +++++++ > > target/ppc/kvm.c | 18 ----- > > target/ppc/kvm_ppc.h | 6 -- > > 8 files changed, 184 insertions(+), 24 deletions(-) > > create mode 100644 docs/papr-pef.txt > > create mode 100644 hw/ppc/pef.c > > create mode 100644 include/hw/ppc/pef.h > > > > diff --git a/docs/confidential-guest-support.txt b/docs/confidential-guest-support.txt > > index 2790425b38..d466aa79d5 100644 > > --- a/docs/confidential-guest-support.txt > > +++ b/docs/confidential-guest-support.txt > > @@ -40,4 +40,6 @@ Currently supported confidential guest mechanisms are: > > AMD Secure Encrypted Virtualization (SEV) > > docs/amd-memory-encryption.txt > > > > +POWER Protected Execution Facility (PEF) > > Maybe add: > > /docs/papr-pef.txt Good idea, added. > > + > > Other mechanisms may be supported in future. > > diff --git a/docs/papr-pef.txt b/docs/papr-pef.txt > > new file mode 100644 > > index 0000000000..798e39f3ed > > --- /dev/null > > +++ b/docs/papr-pef.txt > > @@ -0,0 +1,30 @@ > > +POWER (PAPR) Protected Execution Facility (PEF) > > +=============================================== > > + > > +Protected Execution Facility (PEF), also known as Secure Guest support > > +is a feature found on IBM POWER9 and POWER10 processors. > > + > > +If a suitable firmware including an Ultravisor is installed, it adds > > +an extra memory protection mode to the CPU. The ultravisor manages a > > +pool of secure memory which cannot be accessed by the hypervisor. > > + > > +When this feature is enabled in qemu, a guest can use ultracalls to > > +enter "secure mode". This transfers most of its memory to secure > > +memory, where it cannot be eavesdropped by a compromised hypervisor. > > + > > +Launching > > +--------- > > + > > +To launch a guest which will be permitted to enter PEF secure mode: > > + > > +# ${QEMU} \ > > + -object pef-guest \ > > Add missing id=pef0 Done. > > + -machine confidential-guest-support=pef0 \ > > + ... > > + > > +Live Migration > > +---------------- > > + > > +Live migration is not yet implemented for PEF guests. For > > +consistency, we currently prevent migration if the PEF feature is > > +enabled, whether or not the guest has actuall entered secure mode. > > actually Fixed, thanks. > > > diff --git a/hw/ppc/meson.build b/hw/ppc/meson.build > > index ffa2ec37fa..218631c883 100644 > > --- a/hw/ppc/meson.build > > +++ b/hw/ppc/meson.build > > @@ -27,6 +27,7 @@ ppc_ss.add(when: 'CONFIG_PSERIES', if_true: files( > > 'spapr_nvdimm.c', > > 'spapr_rtas_ddw.c', > > 'spapr_numa.c', > > + 'pef.c', > > )) > > ppc_ss.add(when: 'CONFIG_SPAPR_RNG', if_true: files('spapr_rng.c')) > > ppc_ss.add(when: ['CONFIG_PSERIES', 'CONFIG_LINUX'], if_true: files( > > diff --git a/hw/ppc/pef.c b/hw/ppc/pef.c > > new file mode 100644 > > index 0000000000..b227dc6905 > > --- /dev/null > > +++ b/hw/ppc/pef.c > > @@ -0,0 +1,115 @@ > > +/* > > + * PEF (Protected Execution Facility) for POWER support > > + * > > + * Copyright David Gibson, Redhat Inc. 2020 > > + * > > + * This work is licensed under the terms of the GNU GPL, version 2 or later. > > + * See the COPYING file in the top-level directory. > > + * > > + */ > > + > > +#include "qemu/osdep.h" > > + > > +#include "qapi/error.h" > > +#include "qom/object_interfaces.h" > > +#include "sysemu/kvm.h" > > +#include "migration/blocker.h" > > +#include "exec/confidential-guest-support.h" > > +#include "hw/ppc/pef.h" > > + > > +#define TYPE_PEF_GUEST "pef-guest" > > +#define PEF_GUEST(obj) \ > > + OBJECT_CHECK(PefGuestState, (obj), TYPE_PEF_GUEST) > > + > > +typedef struct PefGuestState PefGuestState; > > + > > Maybe convert to: > > #define TYPE_PEF_GUEST "pef-guest" > OBJECT_DECLARE_SIMPLE_TYPE(PefGuestState, PEF_GUEST); Right, I wasn't previously aware of those helper macros, so I need to use them in a bunch of places. > > +/** > > + * PefGuestState: > > + * > > + * The PefGuestState object is used for creating and managing a PEF > > + * guest. > > + * > > + * # $QEMU \ > > + * -object pef-guest,id=pef0 \ > > + * -machine ...,confidential-guest-support=pef0 > > + */ > > +struct PefGuestState { > > + Object parent_obj; > > +}; > > + > > +#ifdef CONFIG_KVM > > +static int kvmppc_svm_init(Error **errp) > > +{ > > + if (!kvm_check_extension(kvm_state, KVM_CAP_PPC_SECURE_GUEST)) { > > + error_setg(errp, > > + "KVM implementation does not support Secure VMs (is an ultravisor running?)"); > > + return -1; > > + } else { > > + int ret = kvm_vm_enable_cap(kvm_state, KVM_CAP_PPC_SECURE_GUEST, 0, 1); > > + > > + if (ret < 0) { > > + error_setg(errp, > > + "Error enabling PEF with KVM"); > > + return -1; > > + } > > + } > > + > > + return 0; > > +} > > + > > +/* > > + * Don't set error if KVM_PPC_SVM_OFF ioctl is invoked on kernels > > + * that don't support this ioctl. > > + */ > > +void kvmppc_svm_off(Error **errp) > > +{ > > + int rc; > > + > > + if (!kvm_enabled()) { > > + return; > > + } > > + > > + rc = kvm_vm_ioctl(KVM_STATE(current_accel()), KVM_PPC_SVM_OFF); > > + if (rc && rc != -ENOTTY) { > > + error_setg_errno(errp, -rc, "KVM_PPC_SVM_OFF ioctl failed"); > > + } > > +} > > +#else > > +static int kvmppc_svm_init(Error **errp) > > +{ > > + g_assert_not_reached(); > > +} > > +#endif > > + > > +int pef_kvm_init(ConfidentialGuestSupport *cgs, Error **errp) > > +{ > > + if (!object_dynamic_cast(OBJECT(cgs), TYPE_PEF_GUEST)) { > > + return 0; > > + } > > + > > + if (!kvm_enabled()) { > > + error_setg(errp, "PEF requires KVM"); > > + return -1; > > + } > > + > > + return kvmppc_svm_init(errp); > > +} > > + > > +static const TypeInfo pef_guest_info = { > > + .parent = TYPE_OBJECT, > > + .name = TYPE_PEF_GUEST, > > + .instance_size = sizeof(PefGuestState), > > + .interfaces = (InterfaceInfo[]) { > > + { TYPE_CONFIDENTIAL_GUEST_SUPPORT }, > > + { TYPE_USER_CREATABLE }, > > + { } > > + } > > +}; > > + > > +static void > > +pef_register_types(void) > > +{ > > + type_register_static(&pef_guest_info); > > +} > > + > > +type_init(pef_register_types); > > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > > index 2c403b574e..5d0009cae7 100644 > > --- a/hw/ppc/spapr.c > > +++ b/hw/ppc/spapr.c > > @@ -83,6 +83,7 @@ > > #include "hw/ppc/spapr_tpm_proxy.h" > > #include "hw/ppc/spapr_nvdimm.h" > > #include "hw/ppc/spapr_numa.h" > > +#include "hw/ppc/pef.h" > > > > #include "monitor/monitor.h" > > > > @@ -2657,6 +2658,15 @@ static void spapr_machine_init(MachineState *machine) > > long load_limit, fw_size; > > char *filename; > > Error *resize_hpt_err = NULL; > > + Error *local_err = NULL; > > + > > + /* > > + * if Secure VM (PEF) support is configured, then initialize it > > + */ > > + if (pef_kvm_init(machine->cgs, &local_err) < 0) { > > + error_report_err(local_err); > > + exit(1); > > It looks like you just need to pass &error_fatal to pef_kvm_init(). Good point, fixed. > > + } > > > > msi_nonbroken = true; > > > > diff --git a/include/hw/ppc/pef.h b/include/hw/ppc/pef.h > > new file mode 100644 > > index 0000000000..7c92391177 > > --- /dev/null > > +++ b/include/hw/ppc/pef.h > > @@ -0,0 +1,26 @@ > > +/* > > + * PEF (Protected Execution Facility) for POWER support > > + * > > + * Copyright David Gibson, Redhat Inc. 2020 > > + * > > + * This work is licensed under the terms of the GNU GPL, version 2 or later. > > + * See the COPYING file in the top-level directory. > > + * > > + */ > > + > > +#ifndef HW_PPC_PEF_H > > +#define HW_PPC_PEF_H > > + > > +int pef_kvm_init(ConfidentialGuestSupport *cgs, Error **errp); > > + > > +#ifdef CONFIG_KVM > > +void kvmppc_svm_off(Error **errp); > > +#else > > +static inline void kvmppc_svm_off(Error **errp) > > +{ > > +} > > +#endif > > + > > + > > +#endif /* HW_PPC_PEF_H */ > > + > > diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c > > index daf690a678..0c5056dd5b 100644 > > --- a/target/ppc/kvm.c > > +++ b/target/ppc/kvm.c > > @@ -2929,21 +2929,3 @@ void kvmppc_set_reg_tb_offset(PowerPCCPU *cpu, int64_t tb_offset) > > kvm_set_one_reg(cs, KVM_REG_PPC_TB_OFFSET, &tb_offset); > > } > > } > > - > > -/* > > - * Don't set error if KVM_PPC_SVM_OFF ioctl is invoked on kernels > > - * that don't support this ioctl. > > - */ > > -void kvmppc_svm_off(Error **errp) > > -{ > > - int rc; > > - > > - if (!kvm_enabled()) { > > - return; > > - } > > - > > - rc = kvm_vm_ioctl(KVM_STATE(current_accel()), KVM_PPC_SVM_OFF); > > - if (rc && rc != -ENOTTY) { > > - error_setg_errno(errp, -rc, "KVM_PPC_SVM_OFF ioctl failed"); > > - } > > -} > > diff --git a/target/ppc/kvm_ppc.h b/target/ppc/kvm_ppc.h > > index 73ce2bc951..989f61ace0 100644 > > --- a/target/ppc/kvm_ppc.h > > +++ b/target/ppc/kvm_ppc.h > > @@ -39,7 +39,6 @@ int kvmppc_booke_watchdog_enable(PowerPCCPU *cpu); > > target_ulong kvmppc_configure_v3_mmu(PowerPCCPU *cpu, > > bool radix, bool gtse, > > uint64_t proc_tbl); > > -void kvmppc_svm_off(Error **errp); > > #ifndef CONFIG_USER_ONLY > > bool kvmppc_spapr_use_multitce(void); > > int kvmppc_spapr_enable_inkernel_multitce(void); > > @@ -216,11 +215,6 @@ static inline target_ulong kvmppc_configure_v3_mmu(PowerPCCPU *cpu, > > return 0; > > } > > > > -static inline void kvmppc_svm_off(Error **errp) > > -{ > > - return; > > -} > > - > > static inline void kvmppc_set_reg_ppc_online(PowerPCCPU *cpu, > > unsigned int online) > > { >
diff --git a/docs/confidential-guest-support.txt b/docs/confidential-guest-support.txt index 2790425b38..d466aa79d5 100644 --- a/docs/confidential-guest-support.txt +++ b/docs/confidential-guest-support.txt @@ -40,4 +40,6 @@ Currently supported confidential guest mechanisms are: AMD Secure Encrypted Virtualization (SEV) docs/amd-memory-encryption.txt +POWER Protected Execution Facility (PEF) + Other mechanisms may be supported in future. diff --git a/docs/papr-pef.txt b/docs/papr-pef.txt new file mode 100644 index 0000000000..798e39f3ed --- /dev/null +++ b/docs/papr-pef.txt @@ -0,0 +1,30 @@ +POWER (PAPR) Protected Execution Facility (PEF) +=============================================== + +Protected Execution Facility (PEF), also known as Secure Guest support +is a feature found on IBM POWER9 and POWER10 processors. + +If a suitable firmware including an Ultravisor is installed, it adds +an extra memory protection mode to the CPU. The ultravisor manages a +pool of secure memory which cannot be accessed by the hypervisor. + +When this feature is enabled in qemu, a guest can use ultracalls to +enter "secure mode". This transfers most of its memory to secure +memory, where it cannot be eavesdropped by a compromised hypervisor. + +Launching +--------- + +To launch a guest which will be permitted to enter PEF secure mode: + +# ${QEMU} \ + -object pef-guest \ + -machine confidential-guest-support=pef0 \ + ... + +Live Migration +---------------- + +Live migration is not yet implemented for PEF guests. For +consistency, we currently prevent migration if the PEF feature is +enabled, whether or not the guest has actuall entered secure mode. diff --git a/hw/ppc/meson.build b/hw/ppc/meson.build index ffa2ec37fa..218631c883 100644 --- a/hw/ppc/meson.build +++ b/hw/ppc/meson.build @@ -27,6 +27,7 @@ ppc_ss.add(when: 'CONFIG_PSERIES', if_true: files( 'spapr_nvdimm.c', 'spapr_rtas_ddw.c', 'spapr_numa.c', + 'pef.c', )) ppc_ss.add(when: 'CONFIG_SPAPR_RNG', if_true: files('spapr_rng.c')) ppc_ss.add(when: ['CONFIG_PSERIES', 'CONFIG_LINUX'], if_true: files( diff --git a/hw/ppc/pef.c b/hw/ppc/pef.c new file mode 100644 index 0000000000..b227dc6905 --- /dev/null +++ b/hw/ppc/pef.c @@ -0,0 +1,115 @@ +/* + * PEF (Protected Execution Facility) for POWER support + * + * Copyright David Gibson, Redhat Inc. 2020 + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + * + */ + +#include "qemu/osdep.h" + +#include "qapi/error.h" +#include "qom/object_interfaces.h" +#include "sysemu/kvm.h" +#include "migration/blocker.h" +#include "exec/confidential-guest-support.h" +#include "hw/ppc/pef.h" + +#define TYPE_PEF_GUEST "pef-guest" +#define PEF_GUEST(obj) \ + OBJECT_CHECK(PefGuestState, (obj), TYPE_PEF_GUEST) + +typedef struct PefGuestState PefGuestState; + +/** + * PefGuestState: + * + * The PefGuestState object is used for creating and managing a PEF + * guest. + * + * # $QEMU \ + * -object pef-guest,id=pef0 \ + * -machine ...,confidential-guest-support=pef0 + */ +struct PefGuestState { + Object parent_obj; +}; + +#ifdef CONFIG_KVM +static int kvmppc_svm_init(Error **errp) +{ + if (!kvm_check_extension(kvm_state, KVM_CAP_PPC_SECURE_GUEST)) { + error_setg(errp, + "KVM implementation does not support Secure VMs (is an ultravisor running?)"); + return -1; + } else { + int ret = kvm_vm_enable_cap(kvm_state, KVM_CAP_PPC_SECURE_GUEST, 0, 1); + + if (ret < 0) { + error_setg(errp, + "Error enabling PEF with KVM"); + return -1; + } + } + + return 0; +} + +/* + * Don't set error if KVM_PPC_SVM_OFF ioctl is invoked on kernels + * that don't support this ioctl. + */ +void kvmppc_svm_off(Error **errp) +{ + int rc; + + if (!kvm_enabled()) { + return; + } + + rc = kvm_vm_ioctl(KVM_STATE(current_accel()), KVM_PPC_SVM_OFF); + if (rc && rc != -ENOTTY) { + error_setg_errno(errp, -rc, "KVM_PPC_SVM_OFF ioctl failed"); + } +} +#else +static int kvmppc_svm_init(Error **errp) +{ + g_assert_not_reached(); +} +#endif + +int pef_kvm_init(ConfidentialGuestSupport *cgs, Error **errp) +{ + if (!object_dynamic_cast(OBJECT(cgs), TYPE_PEF_GUEST)) { + return 0; + } + + if (!kvm_enabled()) { + error_setg(errp, "PEF requires KVM"); + return -1; + } + + return kvmppc_svm_init(errp); +} + +static const TypeInfo pef_guest_info = { + .parent = TYPE_OBJECT, + .name = TYPE_PEF_GUEST, + .instance_size = sizeof(PefGuestState), + .interfaces = (InterfaceInfo[]) { + { TYPE_CONFIDENTIAL_GUEST_SUPPORT }, + { TYPE_USER_CREATABLE }, + { } + } +}; + +static void +pef_register_types(void) +{ + type_register_static(&pef_guest_info); +} + +type_init(pef_register_types); diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c index 2c403b574e..5d0009cae7 100644 --- a/hw/ppc/spapr.c +++ b/hw/ppc/spapr.c @@ -83,6 +83,7 @@ #include "hw/ppc/spapr_tpm_proxy.h" #include "hw/ppc/spapr_nvdimm.h" #include "hw/ppc/spapr_numa.h" +#include "hw/ppc/pef.h" #include "monitor/monitor.h" @@ -2657,6 +2658,15 @@ static void spapr_machine_init(MachineState *machine) long load_limit, fw_size; char *filename; Error *resize_hpt_err = NULL; + Error *local_err = NULL; + + /* + * if Secure VM (PEF) support is configured, then initialize it + */ + if (pef_kvm_init(machine->cgs, &local_err) < 0) { + error_report_err(local_err); + exit(1); + } msi_nonbroken = true; diff --git a/include/hw/ppc/pef.h b/include/hw/ppc/pef.h new file mode 100644 index 0000000000..7c92391177 --- /dev/null +++ b/include/hw/ppc/pef.h @@ -0,0 +1,26 @@ +/* + * PEF (Protected Execution Facility) for POWER support + * + * Copyright David Gibson, Redhat Inc. 2020 + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + * + */ + +#ifndef HW_PPC_PEF_H +#define HW_PPC_PEF_H + +int pef_kvm_init(ConfidentialGuestSupport *cgs, Error **errp); + +#ifdef CONFIG_KVM +void kvmppc_svm_off(Error **errp); +#else +static inline void kvmppc_svm_off(Error **errp) +{ +} +#endif + + +#endif /* HW_PPC_PEF_H */ + diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c index daf690a678..0c5056dd5b 100644 --- a/target/ppc/kvm.c +++ b/target/ppc/kvm.c @@ -2929,21 +2929,3 @@ void kvmppc_set_reg_tb_offset(PowerPCCPU *cpu, int64_t tb_offset) kvm_set_one_reg(cs, KVM_REG_PPC_TB_OFFSET, &tb_offset); } } - -/* - * Don't set error if KVM_PPC_SVM_OFF ioctl is invoked on kernels - * that don't support this ioctl. - */ -void kvmppc_svm_off(Error **errp) -{ - int rc; - - if (!kvm_enabled()) { - return; - } - - rc = kvm_vm_ioctl(KVM_STATE(current_accel()), KVM_PPC_SVM_OFF); - if (rc && rc != -ENOTTY) { - error_setg_errno(errp, -rc, "KVM_PPC_SVM_OFF ioctl failed"); - } -} diff --git a/target/ppc/kvm_ppc.h b/target/ppc/kvm_ppc.h index 73ce2bc951..989f61ace0 100644 --- a/target/ppc/kvm_ppc.h +++ b/target/ppc/kvm_ppc.h @@ -39,7 +39,6 @@ int kvmppc_booke_watchdog_enable(PowerPCCPU *cpu); target_ulong kvmppc_configure_v3_mmu(PowerPCCPU *cpu, bool radix, bool gtse, uint64_t proc_tbl); -void kvmppc_svm_off(Error **errp); #ifndef CONFIG_USER_ONLY bool kvmppc_spapr_use_multitce(void); int kvmppc_spapr_enable_inkernel_multitce(void); @@ -216,11 +215,6 @@ static inline target_ulong kvmppc_configure_v3_mmu(PowerPCCPU *cpu, return 0; } -static inline void kvmppc_svm_off(Error **errp) -{ - return; -} - static inline void kvmppc_set_reg_ppc_online(PowerPCCPU *cpu, unsigned int online) {
Some upcoming POWER machines have a system called PEF (Protected Execution Facility) which uses a small ultravisor to allow guests to run in a way that they can't be eavesdropped by the hypervisor. The effect is roughly similar to AMD SEV, although the mechanisms are quite different. Most of the work of this is done between the guest, KVM and the ultravisor, with little need for involvement by qemu. However qemu does need to tell KVM to allow secure VMs. Because the availability of secure mode is a guest visible difference which depends on having the right hardware and firmware, we don't enable this by default. In order to run a secure guest you need to create a "pef-guest" object and set the confidential-guest-support property to point to it. Note that this just *allows* secure guests, the architecture of PEF is such that the guest still needs to talk to the ultravisor to enter secure mode. Qemu has no directl way of knowing if the guest is in secure mode, and certainly can't know until well after machine creation time. To start a PEF-capable guest, use the command line options: -object pef-guest,id=pef0 -machine confidential-guest-support=pef0 Signed-off-by: David Gibson <david@gibson.dropbear.id.au> --- docs/confidential-guest-support.txt | 2 + docs/papr-pef.txt | 30 ++++++++ hw/ppc/meson.build | 1 + hw/ppc/pef.c | 115 ++++++++++++++++++++++++++++ hw/ppc/spapr.c | 10 +++ include/hw/ppc/pef.h | 26 +++++++ target/ppc/kvm.c | 18 ----- target/ppc/kvm_ppc.h | 6 -- 8 files changed, 184 insertions(+), 24 deletions(-) create mode 100644 docs/papr-pef.txt create mode 100644 hw/ppc/pef.c create mode 100644 include/hw/ppc/pef.h