| Message ID | 22db2bfb4d6551aed661a9ae95b4fdbef613ca21.1611682609.git.thomas.lendacky@amd.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Qemu SEV-ES guest support | expand |
On 2021-01-26 11:36:46 -0600, Tom Lendacky wrote: > From: Tom Lendacky <thomas.lendacky@amd.com> > > When SEV-ES is enabled, it is not possible modify the guests register > state after it has been initially created, encrypted and measured. > > Normally, an INIT-SIPI-SIPI request is used to boot the AP. However, the > hypervisor cannot emulate this because it cannot update the AP register > state. For the very first boot by an AP, the reset vector CS segment > value and the EIP value must be programmed before the register has been > encrypted and measured. Search the guest firmware for the guest for a > specific GUID that tells Qemu the value of the reset vector to use. > > Cc: Paolo Bonzini <pbonzini@redhat.com> > Cc: "Michael S. Tsirkin" <mst@redhat.com> > Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com> > Cc: Richard Henderson <richard.henderson@linaro.org> > Cc: Eduardo Habkost <ehabkost@redhat.com> > Cc: Marcelo Tosatti <mtosatti@redhat.com> > Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> > --- > accel/kvm/kvm-all.c | 64 ++++++++++++++++++++++++++++++++++++ > accel/stubs/kvm-stub.c | 5 +++ > hw/i386/pc_sysfw.c | 10 +++++- > include/sysemu/kvm.h | 16 +++++++++ > include/sysemu/sev.h | 3 ++ > target/i386/kvm/kvm.c | 2 ++ > target/i386/sev.c | 74 ++++++++++++++++++++++++++++++++++++++++++ > 7 files changed, 173 insertions(+), 1 deletion(-) > > diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c > index 3feb17d965..410879cf94 100644 > --- a/accel/kvm/kvm-all.c > +++ b/accel/kvm/kvm-all.c > @@ -39,6 +39,7 @@ > #include "qemu/main-loop.h" > #include "trace.h" > #include "hw/irq.h" > +#include "sysemu/kvm.h" > #include "sysemu/sev.h" > #include "qapi/visitor.h" > #include "qapi/qapi-types-common.h" > @@ -126,6 +127,12 @@ struct KVMState > /* memory encryption */ > void *memcrypt_handle; > int (*memcrypt_encrypt_data)(void *handle, uint8_t *ptr, uint64_t len); > + int (*memcrypt_save_reset_vector)(void *handle, void *flash_ptr, > + uint64_t flash_size, uint32_t *addr); > + > + uint32_t reset_cs; > + uint32_t reset_ip; > + bool reset_data_valid; > > /* For "info mtree -f" to tell if an MR is registered in KVM */ > int nr_as; > @@ -245,6 +252,62 @@ int kvm_memcrypt_encrypt_data(uint8_t *ptr, uint64_t len) > return 1; > } > > +void kvm_memcrypt_set_reset_vector(CPUState *cpu) > +{ > + X86CPU *x86; > + CPUX86State *env; > + > + /* Only update if we have valid reset information */ > + if (!kvm_state->reset_data_valid) { > + return; > + } > + > + /* Do not update the BSP reset state */ > + if (cpu->cpu_index == 0) { > + return; > + } > + > + x86 = X86_CPU(cpu); > + env = &x86->env; > + > + cpu_x86_load_seg_cache(env, R_CS, 0xf000, kvm_state->reset_cs, 0xffff, > + DESC_P_MASK | DESC_S_MASK | DESC_CS_MASK | > + DESC_R_MASK | DESC_A_MASK); > + > + env->eip = kvm_state->reset_ip; > +} > + > +int kvm_memcrypt_save_reset_vector(void *flash_ptr, uint64_t flash_size) > +{ > + CPUState *cpu; > + uint32_t addr; > + int ret; > + > + if (kvm_memcrypt_enabled() && > + kvm_state->memcrypt_save_reset_vector) { > + > + addr = 0; > + ret = kvm_state->memcrypt_save_reset_vector(kvm_state->memcrypt_handle, > + flash_ptr, flash_size, > + &addr); > + if (ret) { > + return ret; > + } > + > + if (addr) { > + kvm_state->reset_cs = addr & 0xffff0000; > + kvm_state->reset_ip = addr & 0x0000ffff; > + kvm_state->reset_data_valid = true; > + > + CPU_FOREACH(cpu) { > + kvm_memcrypt_set_reset_vector(cpu); > + } > + } > + } > + > + return 0; > +} > + > /* Called with KVMMemoryListener.slots_lock held */ > static KVMSlot *kvm_get_free_slot(KVMMemoryListener *kml) > { > @@ -2216,6 +2279,7 @@ static int kvm_init(MachineState *ms) > } > > kvm_state->memcrypt_encrypt_data = sev_encrypt_data; > + kvm_state->memcrypt_save_reset_vector = sev_es_save_reset_vector; > } > > ret = kvm_arch_init(ms, s); > diff --git a/accel/stubs/kvm-stub.c b/accel/stubs/kvm-stub.c > index 680e099463..162c28429e 100644 > --- a/accel/stubs/kvm-stub.c > +++ b/accel/stubs/kvm-stub.c > @@ -91,6 +91,11 @@ int kvm_memcrypt_encrypt_data(uint8_t *ptr, uint64_t len) > return 1; > } > > +int kvm_memcrypt_save_reset_vector(void *flash_ptr, uint64_t flash_size) > +{ > + return -ENOSYS; > +} > + > #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 436b78c587..edec28842d 100644 > --- a/hw/i386/pc_sysfw.c > +++ b/hw/i386/pc_sysfw.c > @@ -248,7 +248,8 @@ static void pc_system_flash_map(PCMachineState *pcms, > PFlashCFI01 *system_flash; > MemoryRegion *flash_mem; > void *flash_ptr; > - int ret, flash_size; > + uint64_t flash_size; > + int ret; > > assert(PC_MACHINE_GET_CLASS(pcms)->pci_enabled); > > @@ -301,6 +302,13 @@ static void pc_system_flash_map(PCMachineState *pcms, > * search for them > */ > pc_system_parse_ovmf_flash(flash_ptr, flash_size); > + > + ret = kvm_memcrypt_save_reset_vector(flash_ptr, flash_size); > + if (ret) { > + error_report("failed to locate and/or save reset vector"); > + exit(1); > + } > + > ret = kvm_memcrypt_encrypt_data(flash_ptr, flash_size); > if (ret) { > error_report("failed to encrypt pflash rom"); > diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h > index bb5d5cf497..875ca101e3 100644 > --- a/include/sysemu/kvm.h > +++ b/include/sysemu/kvm.h > @@ -249,6 +249,22 @@ bool kvm_memcrypt_enabled(void); > */ > int kvm_memcrypt_encrypt_data(uint8_t *ptr, uint64_t len); > > +/** > + * kvm_memcrypt_set_reset_vector - sets the CS/IP value for the AP if SEV-ES > + * is active. > + */ > +void kvm_memcrypt_set_reset_vector(CPUState *cpu); > + > +/** > + * kvm_memcrypt_save_reset_vector - locates and saves the reset vector to be > + * used as the initial CS/IP value for APs > + * if SEV-ES is active. > + * > + * Return: 1 SEV-ES is active and failed to locate a valid reset vector > + * 0 SEV-ES is not active or successfully located and saved the > + * reset vector address > + */ > +int kvm_memcrypt_save_reset_vector(void *flash_prt, uint64_t flash_size); > > #ifdef NEED_CPU_H > #include "cpu.h" > diff --git a/include/sysemu/sev.h b/include/sysemu/sev.h > index 7ab6e3e31d..6f5ad3fd03 100644 > --- a/include/sysemu/sev.h > +++ b/include/sysemu/sev.h > @@ -20,4 +20,7 @@ void *sev_guest_init(const char *id); > int sev_encrypt_data(void *handle, uint8_t *ptr, uint64_t len); > int sev_inject_launch_secret(const char *hdr, const char *secret, > uint64_t gpa, Error **errp); > +int sev_es_save_reset_vector(void *handle, void *flash_ptr, > + uint64_t flash_size, uint32_t *addr); > + > #endif > diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c > index 6dc1ee052d..aaae79557d 100644 > --- a/target/i386/kvm/kvm.c > +++ b/target/i386/kvm/kvm.c > @@ -1920,6 +1920,8 @@ void kvm_arch_reset_vcpu(X86CPU *cpu) > } > /* enabled by default */ > env->poll_control_msr = 1; > + > + kvm_memcrypt_set_reset_vector(CPU(cpu)); > } > > void kvm_arch_do_init_vcpu(X86CPU *cpu) > diff --git a/target/i386/sev.c b/target/i386/sev.c > index ddec7ebaa7..badc141554 100644 > --- a/target/i386/sev.c > +++ b/target/i386/sev.c > @@ -22,6 +22,7 @@ > #include "qom/object_interfaces.h" > #include "qemu/base64.h" > #include "qemu/module.h" > +#include "qemu/uuid.h" > #include "sysemu/kvm.h" > #include "sev_i386.h" > #include "sysemu/sysemu.h" > @@ -31,6 +32,7 @@ > #include "qom/object.h" > #include "exec/address-spaces.h" > #include "monitor/monitor.h" > +#include "hw/i386/pc.h" > > #define TYPE_SEV_GUEST "sev-guest" > OBJECT_DECLARE_SIMPLE_TYPE(SevGuestState, SEV_GUEST) > @@ -71,6 +73,12 @@ struct SevGuestState { > #define DEFAULT_GUEST_POLICY 0x1 /* disable debug */ > #define DEFAULT_SEV_DEVICE "/dev/sev" > > +#define SEV_INFO_BLOCK_GUID "00f771de-1a7e-4fcb-890e-68c77e2fb44e" > +typedef struct __attribute__((__packed__)) SevInfoBlock { > + /* SEV-ES Reset Vector Address */ > + uint32_t reset_addr; > +} SevInfoBlock; > + > static SevGuestState *sev_guest; > static Error *sev_mig_blocker; > > @@ -896,6 +904,72 @@ int sev_inject_launch_secret(const char *packet_hdr, const char *secret, > return 0; > } > > +static int > +sev_es_parse_reset_block(SevInfoBlock *info, uint32_t *addr) > +{ > + if (!info->reset_addr) { > + error_report("SEV-ES reset address is zero"); > + return 1; > + } > + > + *addr = info->reset_addr; > + > + return 0; > +} > + > +int > +sev_es_save_reset_vector(void *handle, void *flash_ptr, uint64_t flash_size, > + uint32_t *addr) > +{ > + QemuUUID info_guid, *guid; > + SevInfoBlock *info; > + uint8_t *data; > + uint16_t *len; > + > + assert(handle); > + > + /* > + * Initialize the address to zero. An address of zero with a successful > + * return code indicates that SEV-ES is not active. > + */ > + *addr = 0; > + if (!sev_es_enabled()) { > + return 0; > + } > + > + /* > + * Extract the AP reset vector for SEV-ES guests by locating the SEV GUID. > + * The SEV GUID is located on its own (original implementation) or within > + * the Firmware GUID Table (new implementation), either of which are > + * located 32 bytes from the end of the flash. > + * > + * Check the Firmware GUID Table first. > + */ > + if (pc_system_ovmf_table_find(SEV_INFO_BLOCK_GUID, &data, NULL)) { > + return sev_es_parse_reset_block((SevInfoBlock *)data, addr); > + } > + > + /* > + * SEV info block not found in the Firmware GUID Table (or there isn't > + * a Firmware GUID Table), fall back to the original implementation. > + */ > + data = flash_ptr + flash_size - 0x20; Even if the SEV_INFO_BLOCK_GUID is always located at 32 bytes from the end of the flash, isn't it better to define a constant with a value of 0x20? > + > + qemu_uuid_parse(SEV_INFO_BLOCK_GUID, &info_guid); > + info_guid = qemu_uuid_bswap(info_guid); /* GUIDs are LE */ > + > + guid = (QemuUUID *)(data - sizeof(info_guid)); > + if (!qemu_uuid_is_equal(guid, &info_guid)) { > + error_report("SEV information block/Firmware GUID Table block not found in pflash rom"); > + return 1; > + } > + > + len = (uint16_t *)((uint8_t *)guid - sizeof(*len)); > + info = (SevInfoBlock *)(data - le16_to_cpu(*len)); > + > + return sev_es_parse_reset_block(info, addr); > +} > + > static void > sev_register_types(void) > { > -- > 2.30.0 >
On 1/29/21 11:44 AM, Venu Busireddy wrote: > On 2021-01-26 11:36:46 -0600, Tom Lendacky wrote: >> From: Tom Lendacky <thomas.lendacky@amd.com> >> >> When SEV-ES is enabled, it is not possible modify the guests register >> state after it has been initially created, encrypted and measured. >> >> Normally, an INIT-SIPI-SIPI request is used to boot the AP. However, the >> hypervisor cannot emulate this because it cannot update the AP register >> state. For the very first boot by an AP, the reset vector CS segment >> value and the EIP value must be programmed before the register has been >> encrypted and measured. Search the guest firmware for the guest for a >> specific GUID that tells Qemu the value of the reset vector to use. >> >> Cc: Paolo Bonzini <pbonzini@redhat.com> >> Cc: "Michael S. Tsirkin" <mst@redhat.com> >> Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com> >> Cc: Richard Henderson <richard.henderson@linaro.org> >> Cc: Eduardo Habkost <ehabkost@redhat.com> >> Cc: Marcelo Tosatti <mtosatti@redhat.com> >> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> >> --- ... >> + >> + /* >> + * SEV info block not found in the Firmware GUID Table (or there isn't >> + * a Firmware GUID Table), fall back to the original implementation. >> + */ >> + data = flash_ptr + flash_size - 0x20; > > Even if the SEV_INFO_BLOCK_GUID is always located at 32 bytes from the end > of the flash, isn't it better to define a constant with a value of 0x20? A follow-on patch that updates both this and the table parser code from James would probably be best. Thanks, Tom > >> +
diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c index 3feb17d965..410879cf94 100644 --- a/accel/kvm/kvm-all.c +++ b/accel/kvm/kvm-all.c @@ -39,6 +39,7 @@ #include "qemu/main-loop.h" #include "trace.h" #include "hw/irq.h" +#include "sysemu/kvm.h" #include "sysemu/sev.h" #include "qapi/visitor.h" #include "qapi/qapi-types-common.h" @@ -126,6 +127,12 @@ struct KVMState /* memory encryption */ void *memcrypt_handle; int (*memcrypt_encrypt_data)(void *handle, uint8_t *ptr, uint64_t len); + int (*memcrypt_save_reset_vector)(void *handle, void *flash_ptr, + uint64_t flash_size, uint32_t *addr); + + uint32_t reset_cs; + uint32_t reset_ip; + bool reset_data_valid; /* For "info mtree -f" to tell if an MR is registered in KVM */ int nr_as; @@ -245,6 +252,62 @@ int kvm_memcrypt_encrypt_data(uint8_t *ptr, uint64_t len) return 1; } +void kvm_memcrypt_set_reset_vector(CPUState *cpu) +{ + X86CPU *x86; + CPUX86State *env; + + /* Only update if we have valid reset information */ + if (!kvm_state->reset_data_valid) { + return; + } + + /* Do not update the BSP reset state */ + if (cpu->cpu_index == 0) { + return; + } + + x86 = X86_CPU(cpu); + env = &x86->env; + + cpu_x86_load_seg_cache(env, R_CS, 0xf000, kvm_state->reset_cs, 0xffff, + DESC_P_MASK | DESC_S_MASK | DESC_CS_MASK | + DESC_R_MASK | DESC_A_MASK); + + env->eip = kvm_state->reset_ip; +} + +int kvm_memcrypt_save_reset_vector(void *flash_ptr, uint64_t flash_size) +{ + CPUState *cpu; + uint32_t addr; + int ret; + + if (kvm_memcrypt_enabled() && + kvm_state->memcrypt_save_reset_vector) { + + addr = 0; + ret = kvm_state->memcrypt_save_reset_vector(kvm_state->memcrypt_handle, + flash_ptr, flash_size, + &addr); + if (ret) { + return ret; + } + + if (addr) { + kvm_state->reset_cs = addr & 0xffff0000; + kvm_state->reset_ip = addr & 0x0000ffff; + kvm_state->reset_data_valid = true; + + CPU_FOREACH(cpu) { + kvm_memcrypt_set_reset_vector(cpu); + } + } + } + + return 0; +} + /* Called with KVMMemoryListener.slots_lock held */ static KVMSlot *kvm_get_free_slot(KVMMemoryListener *kml) { @@ -2216,6 +2279,7 @@ static int kvm_init(MachineState *ms) } kvm_state->memcrypt_encrypt_data = sev_encrypt_data; + kvm_state->memcrypt_save_reset_vector = sev_es_save_reset_vector; } ret = kvm_arch_init(ms, s); diff --git a/accel/stubs/kvm-stub.c b/accel/stubs/kvm-stub.c index 680e099463..162c28429e 100644 --- a/accel/stubs/kvm-stub.c +++ b/accel/stubs/kvm-stub.c @@ -91,6 +91,11 @@ int kvm_memcrypt_encrypt_data(uint8_t *ptr, uint64_t len) return 1; } +int kvm_memcrypt_save_reset_vector(void *flash_ptr, uint64_t flash_size) +{ + return -ENOSYS; +} + #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 436b78c587..edec28842d 100644 --- a/hw/i386/pc_sysfw.c +++ b/hw/i386/pc_sysfw.c @@ -248,7 +248,8 @@ static void pc_system_flash_map(PCMachineState *pcms, PFlashCFI01 *system_flash; MemoryRegion *flash_mem; void *flash_ptr; - int ret, flash_size; + uint64_t flash_size; + int ret; assert(PC_MACHINE_GET_CLASS(pcms)->pci_enabled); @@ -301,6 +302,13 @@ static void pc_system_flash_map(PCMachineState *pcms, * search for them */ pc_system_parse_ovmf_flash(flash_ptr, flash_size); + + ret = kvm_memcrypt_save_reset_vector(flash_ptr, flash_size); + if (ret) { + error_report("failed to locate and/or save reset vector"); + exit(1); + } + ret = kvm_memcrypt_encrypt_data(flash_ptr, flash_size); if (ret) { error_report("failed to encrypt pflash rom"); diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h index bb5d5cf497..875ca101e3 100644 --- a/include/sysemu/kvm.h +++ b/include/sysemu/kvm.h @@ -249,6 +249,22 @@ bool kvm_memcrypt_enabled(void); */ int kvm_memcrypt_encrypt_data(uint8_t *ptr, uint64_t len); +/** + * kvm_memcrypt_set_reset_vector - sets the CS/IP value for the AP if SEV-ES + * is active. + */ +void kvm_memcrypt_set_reset_vector(CPUState *cpu); + +/** + * kvm_memcrypt_save_reset_vector - locates and saves the reset vector to be + * used as the initial CS/IP value for APs + * if SEV-ES is active. + * + * Return: 1 SEV-ES is active and failed to locate a valid reset vector + * 0 SEV-ES is not active or successfully located and saved the + * reset vector address + */ +int kvm_memcrypt_save_reset_vector(void *flash_prt, uint64_t flash_size); #ifdef NEED_CPU_H #include "cpu.h" diff --git a/include/sysemu/sev.h b/include/sysemu/sev.h index 7ab6e3e31d..6f5ad3fd03 100644 --- a/include/sysemu/sev.h +++ b/include/sysemu/sev.h @@ -20,4 +20,7 @@ void *sev_guest_init(const char *id); int sev_encrypt_data(void *handle, uint8_t *ptr, uint64_t len); int sev_inject_launch_secret(const char *hdr, const char *secret, uint64_t gpa, Error **errp); +int sev_es_save_reset_vector(void *handle, void *flash_ptr, + uint64_t flash_size, uint32_t *addr); + #endif diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c index 6dc1ee052d..aaae79557d 100644 --- a/target/i386/kvm/kvm.c +++ b/target/i386/kvm/kvm.c @@ -1920,6 +1920,8 @@ void kvm_arch_reset_vcpu(X86CPU *cpu) } /* enabled by default */ env->poll_control_msr = 1; + + kvm_memcrypt_set_reset_vector(CPU(cpu)); } void kvm_arch_do_init_vcpu(X86CPU *cpu) diff --git a/target/i386/sev.c b/target/i386/sev.c index ddec7ebaa7..badc141554 100644 --- a/target/i386/sev.c +++ b/target/i386/sev.c @@ -22,6 +22,7 @@ #include "qom/object_interfaces.h" #include "qemu/base64.h" #include "qemu/module.h" +#include "qemu/uuid.h" #include "sysemu/kvm.h" #include "sev_i386.h" #include "sysemu/sysemu.h" @@ -31,6 +32,7 @@ #include "qom/object.h" #include "exec/address-spaces.h" #include "monitor/monitor.h" +#include "hw/i386/pc.h" #define TYPE_SEV_GUEST "sev-guest" OBJECT_DECLARE_SIMPLE_TYPE(SevGuestState, SEV_GUEST) @@ -71,6 +73,12 @@ struct SevGuestState { #define DEFAULT_GUEST_POLICY 0x1 /* disable debug */ #define DEFAULT_SEV_DEVICE "/dev/sev" +#define SEV_INFO_BLOCK_GUID "00f771de-1a7e-4fcb-890e-68c77e2fb44e" +typedef struct __attribute__((__packed__)) SevInfoBlock { + /* SEV-ES Reset Vector Address */ + uint32_t reset_addr; +} SevInfoBlock; + static SevGuestState *sev_guest; static Error *sev_mig_blocker; @@ -896,6 +904,72 @@ int sev_inject_launch_secret(const char *packet_hdr, const char *secret, return 0; } +static int +sev_es_parse_reset_block(SevInfoBlock *info, uint32_t *addr) +{ + if (!info->reset_addr) { + error_report("SEV-ES reset address is zero"); + return 1; + } + + *addr = info->reset_addr; + + return 0; +} + +int +sev_es_save_reset_vector(void *handle, void *flash_ptr, uint64_t flash_size, + uint32_t *addr) +{ + QemuUUID info_guid, *guid; + SevInfoBlock *info; + uint8_t *data; + uint16_t *len; + + assert(handle); + + /* + * Initialize the address to zero. An address of zero with a successful + * return code indicates that SEV-ES is not active. + */ + *addr = 0; + if (!sev_es_enabled()) { + return 0; + } + + /* + * Extract the AP reset vector for SEV-ES guests by locating the SEV GUID. + * The SEV GUID is located on its own (original implementation) or within + * the Firmware GUID Table (new implementation), either of which are + * located 32 bytes from the end of the flash. + * + * Check the Firmware GUID Table first. + */ + if (pc_system_ovmf_table_find(SEV_INFO_BLOCK_GUID, &data, NULL)) { + return sev_es_parse_reset_block((SevInfoBlock *)data, addr); + } + + /* + * SEV info block not found in the Firmware GUID Table (or there isn't + * a Firmware GUID Table), fall back to the original implementation. + */ + data = flash_ptr + flash_size - 0x20; + + qemu_uuid_parse(SEV_INFO_BLOCK_GUID, &info_guid); + info_guid = qemu_uuid_bswap(info_guid); /* GUIDs are LE */ + + guid = (QemuUUID *)(data - sizeof(info_guid)); + if (!qemu_uuid_is_equal(guid, &info_guid)) { + error_report("SEV information block/Firmware GUID Table block not found in pflash rom"); + return 1; + } + + len = (uint16_t *)((uint8_t *)guid - sizeof(*len)); + info = (SevInfoBlock *)(data - le16_to_cpu(*len)); + + return sev_es_parse_reset_block(info, addr); +} + static void sev_register_types(void) {