On Wed, Feb 03, 2021 at 06:50:16PM +0100, Greg Kurz wrote: > On Tue, 2 Feb 2021 15:13:12 +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 direct 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 > > --- > > Reviewed-by: Greg Kurz > > Just some cosmetic comments in case you need to respin. See below. > > > docs/confidential-guest-support.txt | 3 + > > docs/papr-pef.txt | 30 +++++++ > > hw/ppc/meson.build | 1 + > > hw/ppc/pef.c | 133 ++++++++++++++++++++++++++++ > > hw/ppc/spapr.c | 8 +- > > include/hw/ppc/pef.h | 17 ++++ > > target/ppc/kvm.c | 18 ---- > > target/ppc/kvm_ppc.h | 6 -- > > 8 files changed, 191 insertions(+), 25 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 bd439ac800..4da4c91bd3 100644 > > --- a/docs/confidential-guest-support.txt > > +++ b/docs/confidential-guest-support.txt > > @@ -40,4 +40,7 @@ Currently supported confidential guest mechanisms are: > > AMD Secure Encrypted Virtualization (SEV) > > docs/amd-memory-encryption.txt > > > > +POWER Protected Execution Facility (PEF) > > + docs/papr-pef.txt > > + > > 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..72550e9bf8 > > --- /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,id=pef0 \ > > + -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 actually 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..f9fd1f2a71 > > --- /dev/null > > +++ b/hw/ppc/pef.c > > @@ -0,0 +1,133 @@ > > +/* > > + * PEF (Protected Execution Facility) for POWER support > > + * > > + * Copyright Red Hat. > > + * > > + * 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" > > +OBJECT_DECLARE_SIMPLE_TYPE(PefGuest, PEF_GUEST) > > + > > +typedef struct PefGuest PefGuest; > > +typedef struct PefGuestClass PefGuestClass; > > + > > +struct PefGuestClass { > > + ConfidentialGuestSupportClass parent_class; > > +}; > > + > > +/** > > + * PefGuest: > > + * > > + * The PefGuest object is used for creating and managing a PEF > > + * guest. > > + * > > + * # $QEMU \ > > + * -object pef-guest,id=pef0 \ > > + * -machine ...,confidential-guest-support=pef0 > > + */ > > +struct PefGuest { > > + ConfidentialGuestSupport parent_obj; > > +}; > > + > > +static int kvmppc_svm_init(Error **errp) > > FWIW, this function could return bool. Yes, but I feel like returning 0 vs. negative is more idiomatic for errors than a bool. > > +{ > > +#ifdef CONFIG_KVM > > + 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; > > +#else > > + g_assert_not_reached(); > > +#endif > > +} > > + > > +/* > > + * Don't set error if KVM_PPC_SVM_OFF ioctl is invoked on kernels > > + * that don't support this ioctl. > > + */ > > +static int kvmppc_svm_off(Error **errp) > > +{ > > +#ifdef CONFIG_KVM > > + int rc; > > + > > + 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"); > > + return rc; > > The ultimate caller for this is spapr_machine_reset() which doesn't > care for a return value since it passes &error_fatal. Is there any > chance that callers ever need to know about the errno value actually ? > If not, it looks like this could return bool all the same. Probably not, but again, I feel like this is more idiomatic. > > + } > > + return 0; > > +#else > > + g_assert_not_reached(); > > +#endif > > +} > > + > > +int pef_kvm_init(ConfidentialGuestSupport *cgs, Error **errp) > > Ditto. > > > +{ > > + 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); > > +} > > + > > +int pef_kvm_reset(ConfidentialGuestSupport *cgs, Error **errp) > > Ditto. > > > +{ > > + if (!object_dynamic_cast(OBJECT(cgs), TYPE_PEF_GUEST)) { > > + return 0; > > + } > > + > > + /* > > + * If we don't have KVM we should never have been able to > > + * initialize PEF, so we should never get this far > > + */ > > + assert(kvm_enabled()); > > + > > + return kvmppc_svm_off(errp); > > +} > > + > > +OBJECT_DEFINE_TYPE_WITH_INTERFACES(PefGuest, > > + pef_guest, > > + PEF_GUEST, > > + CONFIDENTIAL_GUEST_SUPPORT, > > + { TYPE_USER_CREATABLE }, > > + { NULL }) > > + > > +static void pef_guest_class_init(ObjectClass *oc, void *data) > > +{ > > +} > > + > > +static void pef_guest_init(Object *obj) > > +{ > > +} > > + > > +static void pef_guest_finalize(Object *obj) > > +{ > > +} > > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > > index 6c47466fc2..612356e9ec 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" > > > > @@ -1574,7 +1575,7 @@ static void spapr_machine_reset(MachineState *machine) > > void *fdt; > > int rc; > > > > - kvmppc_svm_off(&error_fatal); > > + pef_kvm_reset(machine->cgs, &error_fatal); > > spapr_caps_apply(spapr); > > > > first_ppc_cpu = POWERPC_CPU(first_cpu); > > @@ -2658,6 +2659,11 @@ static void spapr_machine_init(MachineState *machine) > > char *filename; > > Error *resize_hpt_err = NULL; > > > > + /* > > + * if Secure VM (PEF) support is configured, then initialize it > > + */ > > + pef_kvm_init(machine->cgs, &error_fatal); > > + > > msi_nonbroken = true; > > > > QLIST_INIT(&spapr->phbs); > > diff --git a/include/hw/ppc/pef.h b/include/hw/ppc/pef.h > > new file mode 100644 > > index 0000000000..707dbe524c > > --- /dev/null > > +++ b/include/hw/ppc/pef.h > > @@ -0,0 +1,17 @@ > > +/* > > + * PEF (Protected Execution Facility) for POWER support > > + * > > + * Copyright Red Hat. > > + * > > + * 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); > > +int pef_kvm_reset(ConfidentialGuestSupport *cgs, Error **errp); > > + > > +#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) > > { > -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson