From a8dc82ce828579b92cf602cdc307a6c5b144069c Mon Sep 17 00:00:00 2001 From: Greg Kurz Date: Fri, 14 Aug 2020 09:24:50 +0200 Subject: [PATCH 01/13] qom: Allow optional sugar props MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Global properties have an @optional field, which allows to apply a given property to a given type even if one of its subclasses doesn't support it. This is especially used in the compat code when dealing with the "disable-modern" and "disable-legacy" properties and the "virtio-pci" type. Allow object_register_sugar_prop() to set this field as well. Signed-off-by: Greg Kurz Message-Id: <159738953558.377274.16617742952571083440.stgit@bahia.lan> Signed-off-by: David Gibson Reviewed-by: Eduardo Habkost Reviewed-by: Cornelia Huck Reviewed-by: Philippe Mathieu-Daudé --- include/qom/object.h | 3 ++- qom/object.c | 4 +++- softmmu/rtc.c | 3 ++- softmmu/vl.c | 17 +++++++++++------ 4 files changed, 18 insertions(+), 9 deletions(-) diff --git a/include/qom/object.h b/include/qom/object.h index d378f13a11..6721cd312e 100644 --- a/include/qom/object.h +++ b/include/qom/object.h @@ -638,7 +638,8 @@ bool object_apply_global_props(Object *obj, const GPtrArray *props, Error **errp); void object_set_machine_compat_props(GPtrArray *compat_props); void object_set_accelerator_compat_props(GPtrArray *compat_props); -void object_register_sugar_prop(const char *driver, const char *prop, const char *value); +void object_register_sugar_prop(const char *driver, const char *prop, + const char *value, bool optional); void object_apply_compat_props(Object *obj); /** diff --git a/qom/object.c b/qom/object.c index 2fa0119647..491823db4a 100644 --- a/qom/object.c +++ b/qom/object.c @@ -442,7 +442,8 @@ static GPtrArray *object_compat_props[3]; * other than "-global". These are generally used for syntactic * sugar and legacy command line options. */ -void object_register_sugar_prop(const char *driver, const char *prop, const char *value) +void object_register_sugar_prop(const char *driver, const char *prop, + const char *value, bool optional) { GlobalProperty *g; if (!object_compat_props[2]) { @@ -452,6 +453,7 @@ void object_register_sugar_prop(const char *driver, const char *prop, const char g->driver = g_strdup(driver); g->property = g_strdup(prop); g->value = g_strdup(value); + g->optional = optional; g_ptr_array_add(object_compat_props[2], g); } diff --git a/softmmu/rtc.c b/softmmu/rtc.c index e1e15ef613..5632684fc9 100644 --- a/softmmu/rtc.c +++ b/softmmu/rtc.c @@ -179,7 +179,8 @@ void configure_rtc(QemuOpts *opts) if (!strcmp(value, "slew")) { object_register_sugar_prop("mc146818rtc", "lost_tick_policy", - "slew"); + "slew", + false); } else if (!strcmp(value, "none")) { /* discard is default */ } else { diff --git a/softmmu/vl.c b/softmmu/vl.c index 2bf94ece9c..0d934844ff 100644 --- a/softmmu/vl.c +++ b/softmmu/vl.c @@ -1663,16 +1663,20 @@ static int machine_set_property(void *opaque, return 0; } if (g_str_equal(qom_name, "igd-passthru")) { - object_register_sugar_prop(ACCEL_CLASS_NAME("xen"), qom_name, value); + object_register_sugar_prop(ACCEL_CLASS_NAME("xen"), qom_name, value, + false); return 0; } if (g_str_equal(qom_name, "kvm-shadow-mem")) { - object_register_sugar_prop(ACCEL_CLASS_NAME("kvm"), qom_name, value); + object_register_sugar_prop(ACCEL_CLASS_NAME("kvm"), qom_name, value, + false); return 0; } if (g_str_equal(qom_name, "kernel-irqchip")) { - object_register_sugar_prop(ACCEL_CLASS_NAME("kvm"), qom_name, value); - object_register_sugar_prop(ACCEL_CLASS_NAME("whpx"), qom_name, value); + object_register_sugar_prop(ACCEL_CLASS_NAME("kvm"), qom_name, value, + false); + object_register_sugar_prop(ACCEL_CLASS_NAME("whpx"), qom_name, value, + false); return 0; } @@ -2298,9 +2302,10 @@ static void qemu_process_sugar_options(void) val = g_strdup_printf("%d", (uint32_t) qemu_opt_get_number(qemu_find_opts_singleton("smp-opts"), "cpus", 1)); - object_register_sugar_prop("memory-backend", "prealloc-threads", val); + object_register_sugar_prop("memory-backend", "prealloc-threads", val, + false); g_free(val); - object_register_sugar_prop("memory-backend", "prealloc", "on"); + object_register_sugar_prop("memory-backend", "prealloc", "on", false); } if (watchdog) { From f91f9f254ba10e94468663b23d0b780c240df268 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Tue, 5 May 2020 17:00:30 +1000 Subject: [PATCH 02/13] confidential guest support: Introduce new confidential guest support class Several architectures have mechanisms which are designed to protect guest memory from interference or eavesdropping by a compromised hypervisor. AMD SEV does this with in-chip memory encryption and Intel's TDX can do similar things. POWER's Protected Execution Framework (PEF) accomplishes a similar goal using an ultravisor and new memory protection features, instead of encryption. To (partially) unify handling for these, this introduces a new ConfidentialGuestSupport QOM base class. "Confidential" is kind of vague, but "confidential computing" seems to be the buzzword about these schemes, and "secure" or "protected" are often used in connection to unrelated things (such as hypervisor-from-guest or guest-from-guest security). The "support" in the name is significant because in at least some of the cases it requires the guest to take specific actions in order to protect itself from hypervisor eavesdropping. Signed-off-by: David Gibson --- backends/confidential-guest-support.c | 33 ++++++++++++++++++++ backends/meson.build | 1 + include/exec/confidential-guest-support.h | 38 +++++++++++++++++++++++ include/qemu/typedefs.h | 1 + target/i386/sev.c | 5 +-- 5 files changed, 76 insertions(+), 2 deletions(-) create mode 100644 backends/confidential-guest-support.c create mode 100644 include/exec/confidential-guest-support.h diff --git a/backends/confidential-guest-support.c b/backends/confidential-guest-support.c new file mode 100644 index 0000000000..052fde8db0 --- /dev/null +++ b/backends/confidential-guest-support.c @@ -0,0 +1,33 @@ +/* + * QEMU Confidential Guest support + * + * Copyright Red Hat. + * + * Authors: + * David Gibson + * + * 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 "exec/confidential-guest-support.h" + +OBJECT_DEFINE_ABSTRACT_TYPE(ConfidentialGuestSupport, + confidential_guest_support, + CONFIDENTIAL_GUEST_SUPPORT, + OBJECT) + +static void confidential_guest_support_class_init(ObjectClass *oc, void *data) +{ +} + +static void confidential_guest_support_init(Object *obj) +{ +} + +static void confidential_guest_support_finalize(Object *obj) +{ +} diff --git a/backends/meson.build b/backends/meson.build index 484456ece7..d4221831fc 100644 --- a/backends/meson.build +++ b/backends/meson.build @@ -6,6 +6,7 @@ softmmu_ss.add([files( 'rng-builtin.c', 'rng-egd.c', 'rng.c', + 'confidential-guest-support.c', ), numa]) softmmu_ss.add(when: 'CONFIG_POSIX', if_true: files('rng-random.c')) diff --git a/include/exec/confidential-guest-support.h b/include/exec/confidential-guest-support.h new file mode 100644 index 0000000000..3db6380e63 --- /dev/null +++ b/include/exec/confidential-guest-support.h @@ -0,0 +1,38 @@ +/* + * QEMU Confidential Guest support + * This interface describes the common pieces between various + * schemes for protecting guest memory or other state against a + * compromised hypervisor. This includes memory encryption (AMD's + * SEV and Intel's MKTME) or special protection modes (PEF on POWER, + * or PV on s390x). + * + * Copyright Red Hat. + * + * Authors: + * David Gibson + * + * 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 QEMU_CONFIDENTIAL_GUEST_SUPPORT_H +#define QEMU_CONFIDENTIAL_GUEST_SUPPORT_H + +#ifndef CONFIG_USER_ONLY + +#include "qom/object.h" + +#define TYPE_CONFIDENTIAL_GUEST_SUPPORT "confidential-guest-support" +OBJECT_DECLARE_SIMPLE_TYPE(ConfidentialGuestSupport, CONFIDENTIAL_GUEST_SUPPORT) + +struct ConfidentialGuestSupport { + Object parent; +}; + +typedef struct ConfidentialGuestSupportClass { + ObjectClass parent; +} ConfidentialGuestSupportClass; + +#endif /* !CONFIG_USER_ONLY */ + +#endif /* QEMU_CONFIDENTIAL_GUEST_SUPPORT_H */ diff --git a/include/qemu/typedefs.h b/include/qemu/typedefs.h index 68deb74ef6..dc39b05c30 100644 --- a/include/qemu/typedefs.h +++ b/include/qemu/typedefs.h @@ -37,6 +37,7 @@ typedef struct Chardev Chardev; typedef struct Clock Clock; typedef struct CompatProperty CompatProperty; typedef struct CoMutex CoMutex; +typedef struct ConfidentialGuestSupport ConfidentialGuestSupport; typedef struct CPUAddressSpace CPUAddressSpace; typedef struct CPUState CPUState; typedef struct DeviceListener DeviceListener; diff --git a/target/i386/sev.c b/target/i386/sev.c index 1546606811..b738dc45b6 100644 --- a/target/i386/sev.c +++ b/target/i386/sev.c @@ -31,6 +31,7 @@ #include "qom/object.h" #include "exec/address-spaces.h" #include "monitor/monitor.h" +#include "exec/confidential-guest-support.h" #define TYPE_SEV_GUEST "sev-guest" OBJECT_DECLARE_SIMPLE_TYPE(SevGuestState, SEV_GUEST) @@ -47,7 +48,7 @@ OBJECT_DECLARE_SIMPLE_TYPE(SevGuestState, SEV_GUEST) * -machine ...,memory-encryption=sev0 */ struct SevGuestState { - Object parent_obj; + ConfidentialGuestSupport parent_obj; /* configuration parameters */ char *sev_device; @@ -322,7 +323,7 @@ sev_guest_instance_init(Object *obj) /* sev guest info */ static const TypeInfo sev_guest_info = { - .parent = TYPE_OBJECT, + .parent = TYPE_CONFIDENTIAL_GUEST_SUPPORT, .name = TYPE_SEV_GUEST, .instance_size = sizeof(SevGuestState), .instance_finalize = sev_guest_finalize, From aacdb8441376de05d9e21e93799d5a37b81f0f38 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Tue, 12 Jan 2021 11:58:04 +1100 Subject: [PATCH 03/13] sev: Remove false abstraction of flash encryption When AMD's SEV memory encryption is in use, flash memory banks (which are initialed by pc_system_flash_map()) need to be encrypted with the guest's key, so that the guest can read them. That's abstracted via the kvm_memcrypt_encrypt_data() callback in the KVM state.. except, that it doesn't really abstract much at all. For starters, the only call site is in code specific to the 'pc' family of machine types, so it's obviously specific to those and to x86 to begin with. But it makes a bunch of further assumptions that need not be true about an arbitrary confidential guest system based on memory encryption, let alone one based on other mechanisms: * it assumes that the flash memory is defined to be encrypted with the guest key, rather than being shared with hypervisor * it assumes that that hypervisor has some mechanism to encrypt data into the guest, even though it can't decrypt it out, since that's the whole point * the interface assumes that this encrypt can be done in place, which implies that the hypervisor can write into a confidential guests's memory, even if what it writes isn't meaningful So really, this "abstraction" is actually pretty specific to the way SEV works. So, this patch removes it and instead has the PC flash initialization code call into a SEV specific callback. Signed-off-by: David Gibson Reviewed-by: Cornelia Huck --- accel/kvm/kvm-all.c | 31 ++----------------------------- accel/kvm/sev-stub.c | 9 ++------- accel/stubs/kvm-stub.c | 10 ---------- hw/i386/pc_sysfw.c | 17 ++++++----------- include/sysemu/kvm.h | 16 ---------------- include/sysemu/sev.h | 4 ++-- target/i386/sev-stub.c | 5 +++++ target/i386/sev.c | 24 ++++++++++++++---------- 8 files changed, 31 insertions(+), 85 deletions(-) diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c index 5164d838b9..3526e88b6c 100644 --- a/accel/kvm/kvm-all.c +++ b/accel/kvm/kvm-all.c @@ -123,10 +123,6 @@ struct KVMState KVMMemoryListener memory_listener; QLIST_HEAD(, KVMParkedVcpu) kvm_parked_vcpus; - /* memory encryption */ - void *memcrypt_handle; - int (*memcrypt_encrypt_data)(void *handle, uint8_t *ptr, uint64_t len); - /* For "info mtree -f" to tell if an MR is registered in KVM */ int nr_as; struct KVMAs { @@ -225,26 +221,6 @@ int kvm_get_max_memslots(void) return s->nr_slots; } -bool kvm_memcrypt_enabled(void) -{ - if (kvm_state && kvm_state->memcrypt_handle) { - return true; - } - - return false; -} - -int kvm_memcrypt_encrypt_data(uint8_t *ptr, uint64_t len) -{ - if (kvm_state->memcrypt_handle && - kvm_state->memcrypt_encrypt_data) { - return kvm_state->memcrypt_encrypt_data(kvm_state->memcrypt_handle, - ptr, len); - } - - return 1; -} - /* Called with KVMMemoryListener.slots_lock held */ static KVMSlot *kvm_get_free_slot(KVMMemoryListener *kml) { @@ -2209,13 +2185,10 @@ static int kvm_init(MachineState *ms) * encryption context. */ if (ms->memory_encryption) { - kvm_state->memcrypt_handle = sev_guest_init(ms->memory_encryption); - if (!kvm_state->memcrypt_handle) { - ret = -1; + ret = sev_guest_init(ms->memory_encryption); + if (ret < 0) { goto err; } - - kvm_state->memcrypt_encrypt_data = sev_encrypt_data; } ret = kvm_arch_init(ms, s); diff --git a/accel/kvm/sev-stub.c b/accel/kvm/sev-stub.c index 4f97452585..5db9ab8f00 100644 --- a/accel/kvm/sev-stub.c +++ b/accel/kvm/sev-stub.c @@ -15,12 +15,7 @@ #include "qemu-common.h" #include "sysemu/sev.h" -int sev_encrypt_data(void *handle, uint8_t *ptr, uint64_t len) +int sev_guest_init(const char *id) { - abort(); -} - -void *sev_guest_init(const char *id) -{ - return NULL; + return -1; } diff --git a/accel/stubs/kvm-stub.c b/accel/stubs/kvm-stub.c index 680e099463..0f17acfac0 100644 --- a/accel/stubs/kvm-stub.c +++ b/accel/stubs/kvm-stub.c @@ -81,16 +81,6 @@ int kvm_on_sigbus(int code, void *addr) return 1; } -bool kvm_memcrypt_enabled(void) -{ - return false; -} - -int kvm_memcrypt_encrypt_data(uint8_t *ptr, uint64_t len) -{ - return 1; -} - #ifndef CONFIG_USER_ONLY int kvm_irqchip_add_msi_route(KVMState *s, int vector, PCIDevice *dev) { diff --git a/hw/i386/pc_sysfw.c b/hw/i386/pc_sysfw.c index 92e90ff013..11172214f1 100644 --- a/hw/i386/pc_sysfw.c +++ b/hw/i386/pc_sysfw.c @@ -38,6 +38,7 @@ #include "sysemu/sysemu.h" #include "hw/block/flash.h" #include "sysemu/kvm.h" +#include "sysemu/sev.h" #define FLASH_SECTOR_SIZE 4096 @@ -147,7 +148,7 @@ static void pc_system_flash_map(PCMachineState *pcms, PFlashCFI01 *system_flash; MemoryRegion *flash_mem; void *flash_ptr; - int ret, flash_size; + int flash_size; assert(PC_MACHINE_GET_CLASS(pcms)->pci_enabled); @@ -191,16 +192,10 @@ static void pc_system_flash_map(PCMachineState *pcms, flash_mem = pflash_cfi01_get_memory(system_flash); pc_isa_bios_init(rom_memory, flash_mem, size); - /* Encrypt the pflash boot ROM */ - if (kvm_memcrypt_enabled()) { - flash_ptr = memory_region_get_ram_ptr(flash_mem); - flash_size = memory_region_size(flash_mem); - ret = kvm_memcrypt_encrypt_data(flash_ptr, flash_size); - if (ret) { - error_report("failed to encrypt pflash rom"); - exit(1); - } - } + /* Encrypt the pflash boot ROM, if necessary */ + flash_ptr = memory_region_get_ram_ptr(flash_mem); + flash_size = memory_region_size(flash_mem); + sev_encrypt_flash(flash_ptr, flash_size, &error_fatal); } } } diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h index 739682f3c3..c5546bdecc 100644 --- a/include/sysemu/kvm.h +++ b/include/sysemu/kvm.h @@ -233,22 +233,6 @@ int kvm_has_intx_set_mask(void); */ bool kvm_arm_supports_user_irq(void); -/** - * kvm_memcrypt_enabled - return boolean indicating whether memory encryption - * is enabled - * Returns: 1 memory encryption is enabled - * 0 memory encryption is disabled - */ -bool kvm_memcrypt_enabled(void); - -/** - * kvm_memcrypt_encrypt_data: encrypt the memory range - * - * Return: 1 failed to encrypt the range - * 0 succesfully encrypted memory region - */ -int kvm_memcrypt_encrypt_data(uint8_t *ptr, uint64_t len); - #ifdef NEED_CPU_H #include "cpu.h" diff --git a/include/sysemu/sev.h b/include/sysemu/sev.h index 7ab6e3e31d..7335e59867 100644 --- a/include/sysemu/sev.h +++ b/include/sysemu/sev.h @@ -16,8 +16,8 @@ #include "sysemu/kvm.h" -void *sev_guest_init(const char *id); -int sev_encrypt_data(void *handle, uint8_t *ptr, uint64_t len); +int sev_guest_init(const char *id); +int sev_encrypt_flash(uint8_t *ptr, uint64_t len, Error **errp); int sev_inject_launch_secret(const char *hdr, const char *secret, uint64_t gpa, Error **errp); #endif diff --git a/target/i386/sev-stub.c b/target/i386/sev-stub.c index c1fecc2101..1ac1fd5b94 100644 --- a/target/i386/sev-stub.c +++ b/target/i386/sev-stub.c @@ -54,3 +54,8 @@ int sev_inject_launch_secret(const char *hdr, const char *secret, { return 1; } + +int sev_encrypt_flash(uint8_t *ptr, uint64_t len, Error **errp) +{ + return 0; +} diff --git a/target/i386/sev.c b/target/i386/sev.c index b738dc45b6..8d4e1ea262 100644 --- a/target/i386/sev.c +++ b/target/i386/sev.c @@ -682,7 +682,7 @@ sev_vm_state_change(void *opaque, int running, RunState state) } } -void * +int sev_guest_init(const char *id) { SevGuestState *sev; @@ -695,7 +695,7 @@ sev_guest_init(const char *id) ret = ram_block_discard_disable(true); if (ret) { error_report("%s: cannot disable RAM discard", __func__); - return NULL; + return -1; } sev = lookup_sev_guest_info(id); @@ -766,23 +766,27 @@ sev_guest_init(const char *id) qemu_add_machine_init_done_notifier(&sev_machine_done_notify); qemu_add_vm_change_state_handler(sev_vm_state_change, sev); - return sev; + return 0; err: sev_guest = NULL; ram_block_discard_disable(false); - return NULL; + return -1; } int -sev_encrypt_data(void *handle, uint8_t *ptr, uint64_t len) +sev_encrypt_flash(uint8_t *ptr, uint64_t len, Error **errp) { - SevGuestState *sev = handle; - - assert(sev); + if (!sev_guest) { + return 0; + } /* if SEV is in update state then encrypt the data else do nothing */ - if (sev_check_state(sev, SEV_STATE_LAUNCH_UPDATE)) { - return sev_launch_update_data(sev, ptr, len); + if (sev_check_state(sev_guest, SEV_STATE_LAUNCH_UPDATE)) { + int ret = sev_launch_update_data(sev_guest, ptr, len); + if (ret < 0) { + error_setg(errp, "failed to encrypt pflash rom"); + return ret; + } } return 0; From 6e6a6ca7d9097d1aa68089379cdaa7553dad7a25 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Fri, 24 Jul 2020 12:57:37 +1000 Subject: [PATCH 04/13] confidential guest support: Move side effect out of machine_set_memory_encryption() When the "memory-encryption" property is set, we also disable KSM merging for the guest, since it won't accomplish anything. We want that, but doing it in the property set function itself is thereoretically incorrect, in the unlikely event of some configuration environment that set the property then cleared it again before constructing the guest. More importantly, it makes some other cleanups we want more difficult. So, instead move this logic to machine_run_board_init() conditional on the final value of the property. Signed-off-by: David Gibson Reviewed-by: Richard Henderson Reviewed-by: Greg Kurz Reviewed-by: Cornelia Huck --- hw/core/machine.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) diff --git a/hw/core/machine.c b/hw/core/machine.c index 5d6163ab70..919067b5c9 100644 --- a/hw/core/machine.c +++ b/hw/core/machine.c @@ -437,14 +437,6 @@ static void machine_set_memory_encryption(Object *obj, const char *value, g_free(ms->memory_encryption); ms->memory_encryption = g_strdup(value); - - /* - * With memory encryption, the host can't see the real contents of RAM, - * so there's no point in it trying to merge areas. - */ - if (value) { - machine_set_mem_merge(obj, false, errp); - } } static bool machine_get_nvdimm(Object *obj, Error **errp) @@ -1166,6 +1158,15 @@ void machine_run_board_init(MachineState *machine) cc->deprecation_note); } + if (machine->memory_encryption) { + /* + * With memory encryption, the host can't see the real + * contents of RAM, so there's no point in it trying to merge + * areas. + */ + machine_set_mem_merge(OBJECT(machine), false, &error_abort); + } + machine_class->init(machine); phase_advance(PHASE_MACHINE_INITIALIZED); } From e0292d7c62673546c01d5c6b245735fdfef81840 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Fri, 4 Dec 2020 12:51:51 +1100 Subject: [PATCH 05/13] confidential guest support: Rework the "memory-encryption" property Currently the "memory-encryption" property is only looked at once we get to kvm_init(). Although protection of guest memory from the hypervisor isn't something that could really ever work with TCG, it's not conceptually tied to the KVM accelerator. In addition, the way the string property is resolved to an object is almost identical to how a QOM link property is handled. So, create a new "confidential-guest-support" link property which sets this QOM interface link directly in the machine. For compatibility we keep the "memory-encryption" property, but now implemented in terms of the new property. Signed-off-by: David Gibson Reviewed-by: Greg Kurz Reviewed-by: Cornelia Huck --- accel/kvm/kvm-all.c | 5 +++-- accel/kvm/sev-stub.c | 5 +++-- hw/core/machine.c | 43 +++++++++++++++++++++++++++++++++++++------ include/hw/boards.h | 2 +- include/sysemu/sev.h | 2 +- target/i386/sev.c | 32 ++------------------------------ 6 files changed, 47 insertions(+), 42 deletions(-) diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c index 3526e88b6c..88a6b8c19e 100644 --- a/accel/kvm/kvm-all.c +++ b/accel/kvm/kvm-all.c @@ -2184,8 +2184,9 @@ static int kvm_init(MachineState *ms) * if memory encryption object is specified then initialize the memory * encryption context. */ - if (ms->memory_encryption) { - ret = sev_guest_init(ms->memory_encryption); + if (ms->cgs) { + /* FIXME handle mechanisms other than SEV */ + ret = sev_kvm_init(ms->cgs); if (ret < 0) { goto err; } diff --git a/accel/kvm/sev-stub.c b/accel/kvm/sev-stub.c index 5db9ab8f00..3d4787ae4a 100644 --- a/accel/kvm/sev-stub.c +++ b/accel/kvm/sev-stub.c @@ -15,7 +15,8 @@ #include "qemu-common.h" #include "sysemu/sev.h" -int sev_guest_init(const char *id) +int sev_kvm_init(ConfidentialGuestSupport *cgs) { - return -1; + /* SEV can't be selected if it's not compiled */ + g_assert_not_reached(); } diff --git a/hw/core/machine.c b/hw/core/machine.c index 919067b5c9..f45a795478 100644 --- a/hw/core/machine.c +++ b/hw/core/machine.c @@ -32,6 +32,7 @@ #include "hw/mem/nvdimm.h" #include "migration/global_state.h" #include "migration/vmstate.h" +#include "exec/confidential-guest-support.h" GlobalProperty hw_compat_5_2[] = {}; const size_t hw_compat_5_2_len = G_N_ELEMENTS(hw_compat_5_2); @@ -427,16 +428,37 @@ static char *machine_get_memory_encryption(Object *obj, Error **errp) { MachineState *ms = MACHINE(obj); - return g_strdup(ms->memory_encryption); + if (ms->cgs) { + return g_strdup(object_get_canonical_path_component(OBJECT(ms->cgs))); + } + + return NULL; } static void machine_set_memory_encryption(Object *obj, const char *value, Error **errp) { - MachineState *ms = MACHINE(obj); + Object *cgs = + object_resolve_path_component(object_get_objects_root(), value); - g_free(ms->memory_encryption); - ms->memory_encryption = g_strdup(value); + if (!cgs) { + error_setg(errp, "No such memory encryption object '%s'", value); + return; + } + + object_property_set_link(obj, "confidential-guest-support", cgs, errp); +} + +static void machine_check_confidential_guest_support(const Object *obj, + const char *name, + Object *new_target, + Error **errp) +{ + /* + * So far the only constraint is that the target has the + * TYPE_CONFIDENTIAL_GUEST_SUPPORT interface, and that's checked + * by the QOM core + */ } static bool machine_get_nvdimm(Object *obj, Error **errp) @@ -836,6 +858,15 @@ static void machine_class_init(ObjectClass *oc, void *data) object_class_property_set_description(oc, "suppress-vmdesc", "Set on to disable self-describing migration"); + object_class_property_add_link(oc, "confidential-guest-support", + TYPE_CONFIDENTIAL_GUEST_SUPPORT, + offsetof(MachineState, cgs), + machine_check_confidential_guest_support, + OBJ_PROP_LINK_STRONG); + object_class_property_set_description(oc, "confidential-guest-support", + "Set confidential guest scheme to support"); + + /* For compatibility */ object_class_property_add_str(oc, "memory-encryption", machine_get_memory_encryption, machine_set_memory_encryption); object_class_property_set_description(oc, "memory-encryption", @@ -1158,9 +1189,9 @@ void machine_run_board_init(MachineState *machine) cc->deprecation_note); } - if (machine->memory_encryption) { + if (machine->cgs) { /* - * With memory encryption, the host can't see the real + * With confidential guests, the host can't see the real * contents of RAM, so there's no point in it trying to merge * areas. */ diff --git a/include/hw/boards.h b/include/hw/boards.h index 85af4faf76..a46dfe5d1a 100644 --- a/include/hw/boards.h +++ b/include/hw/boards.h @@ -270,7 +270,7 @@ struct MachineState { bool iommu; bool suppress_vmdesc; bool enable_graphics; - char *memory_encryption; + ConfidentialGuestSupport *cgs; char *ram_memdev_id; /* * convenience alias to ram_memdev_id backend memory region diff --git a/include/sysemu/sev.h b/include/sysemu/sev.h index 7335e59867..3b5b1aacf1 100644 --- a/include/sysemu/sev.h +++ b/include/sysemu/sev.h @@ -16,7 +16,7 @@ #include "sysemu/kvm.h" -int sev_guest_init(const char *id); +int sev_kvm_init(ConfidentialGuestSupport *cgs); int sev_encrypt_flash(uint8_t *ptr, uint64_t len, Error **errp); int sev_inject_launch_secret(const char *hdr, const char *secret, uint64_t gpa, Error **errp); diff --git a/target/i386/sev.c b/target/i386/sev.c index 8d4e1ea262..fa962d533c 100644 --- a/target/i386/sev.c +++ b/target/i386/sev.c @@ -335,26 +335,6 @@ static const TypeInfo sev_guest_info = { } }; -static SevGuestState * -lookup_sev_guest_info(const char *id) -{ - Object *obj; - SevGuestState *info; - - obj = object_resolve_path_component(object_get_objects_root(), id); - if (!obj) { - return NULL; - } - - info = (SevGuestState *) - object_dynamic_cast(obj, TYPE_SEV_GUEST); - if (!info) { - return NULL; - } - - return info; -} - bool sev_enabled(void) { @@ -682,10 +662,9 @@ sev_vm_state_change(void *opaque, int running, RunState state) } } -int -sev_guest_init(const char *id) +int sev_kvm_init(ConfidentialGuestSupport *cgs) { - SevGuestState *sev; + SevGuestState *sev = SEV_GUEST(cgs); char *devname; int ret, fw_error; uint32_t ebx; @@ -698,13 +677,6 @@ sev_guest_init(const char *id) return -1; } - sev = lookup_sev_guest_info(id); - if (!sev) { - error_report("%s: '%s' is not a valid '%s' object", - __func__, id, TYPE_SEV_GUEST); - goto err; - } - sev_guest = sev; sev->state = SEV_STATE_UNINIT; From c9f5aaa6bce819c1863c2a56b187cb9eb521fc92 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Thu, 4 Jun 2020 14:18:52 +1000 Subject: [PATCH 06/13] sev: Add Error ** to sev_kvm_init() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This allows failures to be reported richly and idiomatically. Signed-off-by: David Gibson Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Richard Henderson Reviewed-by: Cornelia Huck --- accel/kvm/kvm-all.c | 4 +++- accel/kvm/sev-stub.c | 2 +- include/sysemu/sev.h | 2 +- target/i386/sev.c | 31 +++++++++++++++---------------- 4 files changed, 20 insertions(+), 19 deletions(-) diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c index 88a6b8c19e..226e1556f9 100644 --- a/accel/kvm/kvm-all.c +++ b/accel/kvm/kvm-all.c @@ -2185,9 +2185,11 @@ static int kvm_init(MachineState *ms) * encryption context. */ if (ms->cgs) { + Error *local_err = NULL; /* FIXME handle mechanisms other than SEV */ - ret = sev_kvm_init(ms->cgs); + ret = sev_kvm_init(ms->cgs, &local_err); if (ret < 0) { + error_report_err(local_err); goto err; } } diff --git a/accel/kvm/sev-stub.c b/accel/kvm/sev-stub.c index 3d4787ae4a..512e205f7f 100644 --- a/accel/kvm/sev-stub.c +++ b/accel/kvm/sev-stub.c @@ -15,7 +15,7 @@ #include "qemu-common.h" #include "sysemu/sev.h" -int sev_kvm_init(ConfidentialGuestSupport *cgs) +int sev_kvm_init(ConfidentialGuestSupport *cgs, Error **errp) { /* SEV can't be selected if it's not compiled */ g_assert_not_reached(); diff --git a/include/sysemu/sev.h b/include/sysemu/sev.h index 3b5b1aacf1..5c5a13c6ca 100644 --- a/include/sysemu/sev.h +++ b/include/sysemu/sev.h @@ -16,7 +16,7 @@ #include "sysemu/kvm.h" -int sev_kvm_init(ConfidentialGuestSupport *cgs); +int sev_kvm_init(ConfidentialGuestSupport *cgs, Error **errp); int sev_encrypt_flash(uint8_t *ptr, uint64_t len, Error **errp); int sev_inject_launch_secret(const char *hdr, const char *secret, uint64_t gpa, Error **errp); diff --git a/target/i386/sev.c b/target/i386/sev.c index fa962d533c..590cb31fa8 100644 --- a/target/i386/sev.c +++ b/target/i386/sev.c @@ -662,7 +662,7 @@ sev_vm_state_change(void *opaque, int running, RunState state) } } -int sev_kvm_init(ConfidentialGuestSupport *cgs) +int sev_kvm_init(ConfidentialGuestSupport *cgs, Error **errp) { SevGuestState *sev = SEV_GUEST(cgs); char *devname; @@ -684,14 +684,14 @@ int sev_kvm_init(ConfidentialGuestSupport *cgs) host_cbitpos = ebx & 0x3f; if (host_cbitpos != sev->cbitpos) { - error_report("%s: cbitpos check failed, host '%d' requested '%d'", - __func__, host_cbitpos, sev->cbitpos); + error_setg(errp, "%s: cbitpos check failed, host '%d' requested '%d'", + __func__, host_cbitpos, sev->cbitpos); goto err; } if (sev->reduced_phys_bits < 1) { - error_report("%s: reduced_phys_bits check failed, it should be >=1," - " requested '%d'", __func__, sev->reduced_phys_bits); + error_setg(errp, "%s: reduced_phys_bits check failed, it should be >=1," + " requested '%d'", __func__, sev->reduced_phys_bits); goto err; } @@ -700,20 +700,19 @@ int sev_kvm_init(ConfidentialGuestSupport *cgs) devname = object_property_get_str(OBJECT(sev), "sev-device", NULL); sev->sev_fd = open(devname, O_RDWR); if (sev->sev_fd < 0) { - error_report("%s: Failed to open %s '%s'", __func__, - devname, strerror(errno)); - } - g_free(devname); - if (sev->sev_fd < 0) { + error_setg(errp, "%s: Failed to open %s '%s'", __func__, + devname, strerror(errno)); + g_free(devname); goto err; } + g_free(devname); ret = sev_platform_ioctl(sev->sev_fd, SEV_PLATFORM_STATUS, &status, &fw_error); if (ret) { - error_report("%s: failed to get platform status ret=%d " - "fw_error='%d: %s'", __func__, ret, fw_error, - fw_error_to_str(fw_error)); + error_setg(errp, "%s: failed to get platform status ret=%d " + "fw_error='%d: %s'", __func__, ret, fw_error, + fw_error_to_str(fw_error)); goto err; } sev->build_id = status.build; @@ -723,14 +722,14 @@ int sev_kvm_init(ConfidentialGuestSupport *cgs) trace_kvm_sev_init(); ret = sev_ioctl(sev->sev_fd, KVM_SEV_INIT, NULL, &fw_error); if (ret) { - error_report("%s: failed to initialize ret=%d fw_error=%d '%s'", - __func__, ret, fw_error, fw_error_to_str(fw_error)); + error_setg(errp, "%s: failed to initialize ret=%d fw_error=%d '%s'", + __func__, ret, fw_error, fw_error_to_str(fw_error)); goto err; } ret = sev_launch_start(sev); if (ret) { - error_report("%s: failed to create encryption context", __func__); + error_setg(errp, "%s: failed to create encryption context", __func__); goto err; } From abc27d4241f99bfaebb0b843b9a967d557ac10e8 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Tue, 20 Oct 2020 17:01:19 +1100 Subject: [PATCH 07/13] confidential guest support: Introduce cgs "ready" flag The platform specific details of mechanisms for implementing confidential guest support may require setup at various points during initialization. Thus, it's not really feasible to have a single cgs initialization hook, but instead each mechanism needs its own initialization calls in arch or machine specific code. However, to make it harder to have a bug where a mechanism isn't properly initialized under some circumstances, we want to have a common place, late in boot, where we verify that cgs has been initialized if it was requested. This patch introduces a ready flag to the ConfidentialGuestSupport base type to accomplish this, which we verify in qemu_machine_creation_done(). Signed-off-by: David Gibson Reviewed-by: Dr. David Alan Gilbert Reviewed-by: Greg Kurz --- include/exec/confidential-guest-support.h | 24 +++++++++++++++++++++++ softmmu/vl.c | 10 ++++++++++ target/i386/sev.c | 2 ++ 3 files changed, 36 insertions(+) diff --git a/include/exec/confidential-guest-support.h b/include/exec/confidential-guest-support.h index 3db6380e63..ba2dd4b5df 100644 --- a/include/exec/confidential-guest-support.h +++ b/include/exec/confidential-guest-support.h @@ -27,6 +27,30 @@ OBJECT_DECLARE_SIMPLE_TYPE(ConfidentialGuestSupport, CONFIDENTIAL_GUEST_SUPPORT) struct ConfidentialGuestSupport { Object parent; + + /* + * ready: flag set by CGS initialization code once it's ready to + * start executing instructions in a potentially-secure + * guest + * + * The definition here is a bit fuzzy, because this is essentially + * part of a self-sanity-check, rather than a strict mechanism. + * + * It's not feasible to have a single point in the common machine + * init path to configure confidential guest support, because + * different mechanisms have different interdependencies requiring + * initialization in different places, often in arch or machine + * type specific code. It's also usually not possible to check + * for invalid configurations until that initialization code. + * That means it would be very easy to have a bug allowing CGS + * init to be bypassed entirely in certain configurations. + * + * Silently ignoring a requested security feature would be bad, so + * to avoid that we check late in init that this 'ready' flag is + * set if CGS was requested. If the CGS init hasn't happened, and + * so 'ready' is not set, we'll abort. + */ + bool ready; }; typedef struct ConfidentialGuestSupportClass { diff --git a/softmmu/vl.c b/softmmu/vl.c index 0d934844ff..9eb9dab1fc 100644 --- a/softmmu/vl.c +++ b/softmmu/vl.c @@ -101,6 +101,7 @@ #include "qemu/plugin.h" #include "qemu/queue.h" #include "sysemu/arch_init.h" +#include "exec/confidential-guest-support.h" #include "ui/qemu-spice.h" #include "qapi/string-input-visitor.h" @@ -2498,6 +2499,8 @@ static void qemu_create_cli_devices(void) static void qemu_machine_creation_done(void) { + MachineState *machine = MACHINE(qdev_get_machine()); + /* Did we create any drives that we failed to create a device for? */ drive_check_orphaned(); @@ -2517,6 +2520,13 @@ static void qemu_machine_creation_done(void) qdev_machine_creation_done(); + if (machine->cgs) { + /* + * Verify that Confidential Guest Support has actually been initialized + */ + assert(machine->cgs->ready); + } + if (foreach_device_config(DEV_GDB, gdbserver_start) < 0) { exit(1); } diff --git a/target/i386/sev.c b/target/i386/sev.c index 590cb31fa8..f9e9b5d8ae 100644 --- a/target/i386/sev.c +++ b/target/i386/sev.c @@ -737,6 +737,8 @@ int sev_kvm_init(ConfidentialGuestSupport *cgs, Error **errp) qemu_add_machine_init_done_notifier(&sev_machine_done_notify); qemu_add_vm_change_state_handler(sev_vm_state_change, sev); + cgs->ready = true; + return 0; err: sev_guest = NULL; From ec78e2cda3e006e0e01e2177caf3718db5600635 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Fri, 16 Oct 2020 14:52:30 +1100 Subject: [PATCH 08/13] confidential guest support: Move SEV initialization into arch specific code While we've abstracted some (potential) differences between mechanisms for securing guest memory, the initialization is still specific to SEV. Given that, move it into x86's kvm_arch_init() code, rather than the generic kvm_init() code. Signed-off-by: David Gibson Reviewed-by: Cornelia Huck Reviewed-by: Greg Kurz --- accel/kvm/kvm-all.c | 14 -------------- accel/kvm/sev-stub.c | 4 ++-- target/i386/kvm/kvm.c | 20 ++++++++++++++++++++ target/i386/sev.c | 7 ++++++- 4 files changed, 28 insertions(+), 17 deletions(-) diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c index 226e1556f9..e72a19aaf8 100644 --- a/accel/kvm/kvm-all.c +++ b/accel/kvm/kvm-all.c @@ -2180,20 +2180,6 @@ static int kvm_init(MachineState *ms) kvm_state = s; - /* - * if memory encryption object is specified then initialize the memory - * encryption context. - */ - if (ms->cgs) { - Error *local_err = NULL; - /* FIXME handle mechanisms other than SEV */ - ret = sev_kvm_init(ms->cgs, &local_err); - if (ret < 0) { - error_report_err(local_err); - goto err; - } - } - ret = kvm_arch_init(ms, s); if (ret < 0) { goto err; diff --git a/accel/kvm/sev-stub.c b/accel/kvm/sev-stub.c index 512e205f7f..9587d1b2a3 100644 --- a/accel/kvm/sev-stub.c +++ b/accel/kvm/sev-stub.c @@ -17,6 +17,6 @@ int sev_kvm_init(ConfidentialGuestSupport *cgs, Error **errp) { - /* SEV can't be selected if it's not compiled */ - g_assert_not_reached(); + /* If we get here, cgs must be some non-SEV thing */ + return 0; } diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c index 6dc1ee052d..4788139128 100644 --- a/target/i386/kvm/kvm.c +++ b/target/i386/kvm/kvm.c @@ -42,6 +42,7 @@ #include "hw/i386/intel_iommu.h" #include "hw/i386/x86-iommu.h" #include "hw/i386/e820_memory_layout.h" +#include "sysemu/sev.h" #include "hw/pci/pci.h" #include "hw/pci/msi.h" @@ -2135,6 +2136,25 @@ int kvm_arch_init(MachineState *ms, KVMState *s) uint64_t shadow_mem; int ret; struct utsname utsname; + Error *local_err = NULL; + + /* + * Initialize SEV context, if required + * + * If no memory encryption is requested (ms->cgs == NULL) this is + * a no-op. + * + * It's also a no-op if a non-SEV confidential guest support + * mechanism is selected. SEV is the only mechanism available to + * select on x86 at present, so this doesn't arise, but if new + * mechanisms are supported in future (e.g. TDX), they'll need + * their own initialization either here or elsewhere. + */ + ret = sev_kvm_init(ms->cgs, &local_err); + if (ret < 0) { + error_report_err(local_err); + return ret; + } if (!kvm_check_extension(s, KVM_CAP_IRQ_ROUTING)) { error_report("kvm: KVM_CAP_IRQ_ROUTING not supported by KVM"); diff --git a/target/i386/sev.c b/target/i386/sev.c index f9e9b5d8ae..11c9a3cc21 100644 --- a/target/i386/sev.c +++ b/target/i386/sev.c @@ -664,13 +664,18 @@ sev_vm_state_change(void *opaque, int running, RunState state) int sev_kvm_init(ConfidentialGuestSupport *cgs, Error **errp) { - SevGuestState *sev = SEV_GUEST(cgs); + SevGuestState *sev + = (SevGuestState *)object_dynamic_cast(OBJECT(cgs), TYPE_SEV_GUEST); char *devname; int ret, fw_error; uint32_t ebx; uint32_t host_cbitpos; struct sev_user_data_status status = {}; + if (!sev) { + return 0; + } + ret = ram_block_discard_disable(true); if (ret) { error_report("%s: cannot disable RAM discard", __func__); From 64d19f333464a877f3ebe538510a10a514db0eb9 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Fri, 8 Jan 2021 13:23:09 +1100 Subject: [PATCH 09/13] confidential guest support: Update documentation Now that we've implemented a generic machine option for configuring various confidential guest support mechanisms: 1. Update docs/amd-memory-encryption.txt to reference this rather than the earlier SEV specific option 2. Add a docs/confidential-guest-support.txt to cover the generalities of the confidential guest support scheme Signed-off-by: David Gibson Reviewed-by: Greg Kurz --- docs/amd-memory-encryption.txt | 2 +- docs/confidential-guest-support.txt | 43 +++++++++++++++++++++++++++++ 2 files changed, 44 insertions(+), 1 deletion(-) create mode 100644 docs/confidential-guest-support.txt diff --git a/docs/amd-memory-encryption.txt b/docs/amd-memory-encryption.txt index 80b8eb00e9..145896aec7 100644 --- a/docs/amd-memory-encryption.txt +++ b/docs/amd-memory-encryption.txt @@ -73,7 +73,7 @@ complete flow chart. To launch a SEV guest # ${QEMU} \ - -machine ...,memory-encryption=sev0 \ + -machine ...,confidential-guest-support=sev0 \ -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=1 Debugging diff --git a/docs/confidential-guest-support.txt b/docs/confidential-guest-support.txt new file mode 100644 index 0000000000..bd439ac800 --- /dev/null +++ b/docs/confidential-guest-support.txt @@ -0,0 +1,43 @@ +Confidential Guest Support +========================== + +Traditionally, hypervisors such as QEMU have complete access to a +guest's memory and other state, meaning that a compromised hypervisor +can compromise any of its guests. A number of platforms have added +mechanisms in hardware and/or firmware which give guests at least some +protection from a compromised hypervisor. This is obviously +especially desirable for public cloud environments. + +These mechanisms have different names and different modes of +operation, but are often referred to as Secure Guests or Confidential +Guests. We use the term "Confidential Guest Support" to distinguish +this from other aspects of guest security (such as security against +attacks from other guests, or from network sources). + +Running a Confidential Guest +---------------------------- + +To run a confidential guest you need to add two command line parameters: + +1. Use "-object" to create a "confidential guest support" object. The + type and parameters will vary with the specific mechanism to be + used +2. Set the "confidential-guest-support" machine parameter to the ID of + the object from (1). + +Example (for AMD SEV):: + + qemu-system-x86_64 \ + \ + -machine ...,confidential-guest-support=sev0 \ + -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=1 + +Supported mechanisms +-------------------- + +Currently supported confidential guest mechanisms are: + +AMD Secure Encrypted Virtualization (SEV) + docs/amd-memory-encryption.txt + +Other mechanisms may be supported in future. From 6c8ebe30ea8055fce8b24730e970532b3c849fdb Mon Sep 17 00:00:00 2001 From: David Gibson Date: Wed, 8 Apr 2020 15:10:03 +1000 Subject: [PATCH 10/13] spapr: Add PEF based confidential guest support 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 --- 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) +{ +#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; + } + return 0; +#else + 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); +} + +int pef_kvm_reset(ConfidentialGuestSupport *cgs, Error **errp) +{ + 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) { From 6742eefc9314678bba39e461fe8cdd0a841c3e92 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Thu, 4 Jun 2020 15:24:27 +1000 Subject: [PATCH 11/13] spapr: PEF: prevent migration We haven't yet implemented the fairly involved handshaking that will be needed to migrate PEF protected guests. For now, just use a migration blocker so we get a meaningful error if someone attempts this (this is the same approach used by AMD SEV). Signed-off-by: David Gibson Reviewed-by: Dr. David Alan Gilbert Reviewed-by: Greg Kurz --- hw/ppc/pef.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/hw/ppc/pef.c b/hw/ppc/pef.c index f9fd1f2a71..573be3ed79 100644 --- a/hw/ppc/pef.c +++ b/hw/ppc/pef.c @@ -44,6 +44,8 @@ struct PefGuest { static int kvmppc_svm_init(Error **errp) { #ifdef CONFIG_KVM + static Error *pef_mig_blocker; + 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?)"); @@ -58,6 +60,11 @@ static int kvmppc_svm_init(Error **errp) } } + /* add migration blocker */ + error_setg(&pef_mig_blocker, "PEF: Migration is not implemented"); + /* NB: This can fail if --only-migratable is used */ + migrate_add_blocker(pef_mig_blocker, &error_fatal); + return 0; #else g_assert_not_reached(); From 9f88a7a3df11a5aaa6212ea535d40d5f92561683 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Thu, 4 Jun 2020 14:20:24 +1000 Subject: [PATCH 12/13] confidential guest support: Alter virtio default properties for protected guests The default behaviour for virtio devices is not to use the platforms normal DMA paths, but instead to use the fact that it's running in a hypervisor to directly access guest memory. That doesn't work if the guest's memory is protected from hypervisor access, such as with AMD's SEV or POWER's PEF. So, if a confidential guest mechanism is enabled, then apply the iommu_platform=on option so it will go through normal DMA mechanisms. Those will presumably have some way of marking memory as shared with the hypervisor or hardware so that DMA will work. Signed-off-by: David Gibson Reviewed-by: Dr. David Alan Gilbert Reviewed-by: Cornelia Huck Reviewed-by: Greg Kurz --- hw/core/machine.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/hw/core/machine.c b/hw/core/machine.c index f45a795478..970046f438 100644 --- a/hw/core/machine.c +++ b/hw/core/machine.c @@ -33,6 +33,8 @@ #include "migration/global_state.h" #include "migration/vmstate.h" #include "exec/confidential-guest-support.h" +#include "hw/virtio/virtio.h" +#include "hw/virtio/virtio-pci.h" GlobalProperty hw_compat_5_2[] = {}; const size_t hw_compat_5_2_len = G_N_ELEMENTS(hw_compat_5_2); @@ -1196,6 +1198,17 @@ void machine_run_board_init(MachineState *machine) * areas. */ machine_set_mem_merge(OBJECT(machine), false, &error_abort); + + /* + * Virtio devices can't count on directly accessing guest + * memory, so they need iommu_platform=on to use normal DMA + * mechanisms. That requires also disabling legacy virtio + * support for those virtio pci devices which allow it. + */ + object_register_sugar_prop(TYPE_VIRTIO_PCI, "disable-legacy", + "on", true); + object_register_sugar_prop(TYPE_VIRTIO_DEVICE, "iommu_platform", + "on", false); } machine_class->init(machine); From 651615d92d244a6dfd7c81ab97bd3369fbe41d06 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Thu, 23 Jul 2020 14:36:45 +1000 Subject: [PATCH 13/13] s390: Recognize confidential-guest-support option 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 by the "confidential-guest-support" 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 confidential-guest-support 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 confidential-guest-support is set, we will either create a guest capable of entering PV mode, or fail outright. - If confidential-guest-support is not set, guests 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. To start a guest supporting Protected Virtualization using the new option use the command line arguments: -object s390-pv-guest,id=pv0 -machine confidential-guest-support=pv0 Signed-off-by: David Gibson Tested-by: Christian Borntraeger Reviewed-by: Christian Borntraeger --- docs/confidential-guest-support.txt | 3 ++ docs/system/s390x/protvirt.rst | 19 ++++++--- hw/s390x/pv.c | 62 +++++++++++++++++++++++++++++ hw/s390x/s390-virtio-ccw.c | 3 ++ include/hw/s390x/pv.h | 17 ++++++++ 5 files changed, 98 insertions(+), 6 deletions(-) diff --git a/docs/confidential-guest-support.txt b/docs/confidential-guest-support.txt index 4da4c91bd3..71d07ba57a 100644 --- a/docs/confidential-guest-support.txt +++ b/docs/confidential-guest-support.txt @@ -43,4 +43,7 @@ AMD Secure Encrypted Virtualization (SEV) POWER Protected Execution Facility (PEF) docs/papr-pef.txt +s390x Protected Virtualization (PV) + docs/system/s390x/protvirt.rst + Other mechanisms may be supported in future. diff --git a/docs/system/s390x/protvirt.rst b/docs/system/s390x/protvirt.rst index 712974ad87..0f481043d9 100644 --- a/docs/system/s390x/protvirt.rst +++ b/docs/system/s390x/protvirt.rst @@ -22,15 +22,22 @@ If those requirements are met, the capability `KVM_CAP_S390_PROTECTED` will indicate that KVM can support PVMs on that LPAR. -QEMU Settings -------------- +Running a Protected Virtual Machine +----------------------------------- -To indicate to the VM that it can transition into protected mode, the +To run a PVM you will need to select a CPU model which includes the `Unpack facility` (stfle bit 161 represented by the feature -`unpack`/`S390_FEAT_UNPACK`) needs to be part of the cpu model of -the VM. +`unpack`/`S390_FEAT_UNPACK`), and add these options to the command line:: + + -object s390-pv-guest,id=pv0 \ + -machine confidential-guest-support=pv0 + +Adding these options will: + +* Ensure the `unpack` facility is available +* Enable the IOMMU by default for all I/O devices +* Initialize the PV mechanism -All I/O devices need to use the IOMMU. Passthrough (vfio) devices are currently not supported. Host huge page backings are not supported. However guests can use huge diff --git a/hw/s390x/pv.c b/hw/s390x/pv.c index ab3a2482aa..93eccfc05d 100644 --- a/hw/s390x/pv.c +++ b/hw/s390x/pv.c @@ -14,8 +14,11 @@ #include #include "cpu.h" +#include "qapi/error.h" #include "qemu/error-report.h" #include "sysemu/kvm.h" +#include "qom/object_interfaces.h" +#include "exec/confidential-guest-support.h" #include "hw/s390x/ipl.h" #include "hw/s390x/pv.h" @@ -111,3 +114,62 @@ 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" +OBJECT_DECLARE_SIMPLE_TYPE(S390PVGuest, S390_PV_GUEST) + +/** + * S390PVGuest: + * + * The S390PVGuest object is basically a dummy used to tell the + * confidential guest support system to use s390's PV mechanism. + * + * # $QEMU \ + * -object s390-pv-guest,id=pv0 \ + * -machine ...,confidential-guest-support=pv0 + */ +struct S390PVGuest { + ConfidentialGuestSupport parent_obj; +}; + +typedef struct S390PVGuestClass S390PVGuestClass; + +struct S390PVGuestClass { + ConfidentialGuestSupportClass parent_class; +}; + +int s390_pv_kvm_init(ConfidentialGuestSupport *cgs, Error **errp) +{ + if (!object_dynamic_cast(OBJECT(cgs), TYPE_S390_PV_GUEST)) { + return 0; + } + + if (!s390_has_feat(S390_FEAT_UNPACK)) { + error_setg(errp, + "CPU model does not support Protected Virtualization"); + return -1; + } + + cgs->ready = true; + + return 0; +} + +OBJECT_DEFINE_TYPE_WITH_INTERFACES(S390PVGuest, + s390_pv_guest, + S390_PV_GUEST, + CONFIDENTIAL_GUEST_SUPPORT, + { TYPE_USER_CREATABLE }, + { NULL }) + +static void s390_pv_guest_class_init(ObjectClass *oc, void *data) +{ +} + +static void s390_pv_guest_init(Object *obj) +{ +} + +static void s390_pv_guest_finalize(Object *obj) +{ +} diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c index a2d9a79c84..2972b607f3 100644 --- a/hw/s390x/s390-virtio-ccw.c +++ b/hw/s390x/s390-virtio-ccw.c @@ -250,6 +250,9 @@ static void ccw_init(MachineState *machine) /* init CPUs (incl. CPU model) early so s390_has_feature() works */ s390_init_cpus(machine); + /* Need CPU model to be determined before we can set up PV */ + s390_pv_init(machine->cgs, &error_fatal); + s390_flic_init(); /* init the SIGP facility */ diff --git a/include/hw/s390x/pv.h b/include/hw/s390x/pv.h index aee758bc2d..1f1f545bfc 100644 --- a/include/hw/s390x/pv.h +++ b/include/hw/s390x/pv.h @@ -12,6 +12,9 @@ #ifndef HW_S390_PV_H #define HW_S390_PV_H +#include "qapi/error.h" +#include "sysemu/kvm.h" + #ifdef CONFIG_KVM #include "cpu.h" #include "hw/s390x/s390-virtio-ccw.h" @@ -55,4 +58,18 @@ static inline void s390_pv_unshare(void) {} static inline void s390_pv_inject_reset_error(CPUState *cs) {}; #endif /* CONFIG_KVM */ +int s390_pv_kvm_init(ConfidentialGuestSupport *cgs, Error **errp); +static inline int s390_pv_init(ConfidentialGuestSupport *cgs, Error **errp) +{ + if (!cgs) { + return 0; + } + if (kvm_enabled()) { + return s390_pv_kvm_init(cgs, errp); + } + + error_setg(errp, "Protected Virtualization requires KVM"); + return -1; +} + #endif /* HW_S390_PV_H */