diff options
| -rw-r--r-- | target/i386/sev.c | 254 | ||||
| -rw-r--r-- | target/i386/sev.h | 2 |
2 files changed, 246 insertions, 10 deletions
diff --git a/target/i386/sev.c b/target/i386/sev.c index a13f91e615..1296f4feb6 100644 --- a/target/i386/sev.c +++ b/target/i386/sev.c @@ -41,7 +41,9 @@ #include "confidential-guest.h" #include "hw/i386/pc.h" #include "system/address-spaces.h" +#include "hw/i386/e820_memory_layout.h" #include "qemu/queue.h" +#include "qemu/cutils.h" OBJECT_DECLARE_TYPE(SevCommonState, SevCommonStateClass, SEV_COMMON) OBJECT_DECLARE_TYPE(SevGuestState, SevCommonStateClass, SEV_GUEST) @@ -50,6 +52,9 @@ OBJECT_DECLARE_TYPE(SevSnpGuestState, SevCommonStateClass, SEV_SNP_GUEST) /* hard code sha256 digest size */ #define HASH_SIZE 32 +/* Hard coded GPA that KVM uses for the VMSA */ +#define KVM_VMSA_GPA 0xFFFFFFFFF000 + /* Convert between SEV-ES VMSA and SegmentCache flags/attributes */ #define FLAGS_VMSA_TO_SEGCACHE(flags) \ ((((flags) & 0xff00) << 12) | (((flags) & 0xff) << 8)) @@ -480,6 +485,103 @@ static void sev_apply_cpu_context(CPUState *cpu) } } +static int check_vmsa_supported(hwaddr gpa, const struct sev_es_save_area *vmsa, + Error **errp) +{ + struct sev_es_save_area vmsa_check; + + /* + * KVM always populates the VMSA at a fixed GPA which cannot be modified + * from userspace. Specifying a different GPA will not prevent the guest + * from starting but will cause the launch measurement to be different + * from expected. Therefore check that the provided GPA matches the KVM + * hardcoded value. + */ + if (gpa != KVM_VMSA_GPA) { + error_setg(errp, + "%s: The VMSA GPA must be %lX but is specified as %lX", + __func__, KVM_VMSA_GPA, gpa); + return -1; + } + + /* + * Clear all supported fields so we can then check the entire structure + * is zero. + */ + memcpy(&vmsa_check, vmsa, sizeof(struct sev_es_save_area)); + memset(&vmsa_check.es, 0, sizeof(vmsa_check.es)); + memset(&vmsa_check.cs, 0, sizeof(vmsa_check.cs)); + memset(&vmsa_check.ss, 0, sizeof(vmsa_check.ss)); + memset(&vmsa_check.ds, 0, sizeof(vmsa_check.ds)); + memset(&vmsa_check.fs, 0, sizeof(vmsa_check.fs)); + memset(&vmsa_check.gs, 0, sizeof(vmsa_check.gs)); + memset(&vmsa_check.gdtr, 0, sizeof(vmsa_check.gdtr)); + memset(&vmsa_check.idtr, 0, sizeof(vmsa_check.idtr)); + memset(&vmsa_check.ldtr, 0, sizeof(vmsa_check.ldtr)); + memset(&vmsa_check.tr, 0, sizeof(vmsa_check.tr)); + vmsa_check.efer = 0; + vmsa_check.cr0 = 0; + vmsa_check.cr3 = 0; + vmsa_check.cr4 = 0; + vmsa_check.xcr0 = 0; + vmsa_check.dr6 = 0; + vmsa_check.dr7 = 0; + vmsa_check.rax = 0; + vmsa_check.rcx = 0; + vmsa_check.rdx = 0; + vmsa_check.rbx = 0; + vmsa_check.rsp = 0; + vmsa_check.rbp = 0; + vmsa_check.rsi = 0; + vmsa_check.rdi = 0; + vmsa_check.r8 = 0; + vmsa_check.r9 = 0; + vmsa_check.r10 = 0; + vmsa_check.r11 = 0; + vmsa_check.r12 = 0; + vmsa_check.r13 = 0; + vmsa_check.r14 = 0; + vmsa_check.r15 = 0; + vmsa_check.rip = 0; + vmsa_check.rflags = 0; + + vmsa_check.g_pat = 0; + vmsa_check.xcr0 = 0; + + vmsa_check.x87_fcw = 0; + vmsa_check.mxcsr = 0; + + if (sev_snp_enabled()) { + if (vmsa_check.sev_features != SVM_SEV_FEAT_SNP_ACTIVE) { + error_setg(errp, + "%s: sev_features in the VMSA contains an unsupported " + "value. For SEV-SNP, sev_features must be set to %x.", + __func__, SVM_SEV_FEAT_SNP_ACTIVE); + return -1; + } + vmsa_check.sev_features = 0; + } else { + if (vmsa_check.sev_features != 0) { + error_setg(errp, + "%s: sev_features in the VMSA contains an unsupported " + "value. For SEV-ES and SEV, sev_features must be " + "set to 0.", __func__); + return -1; + } + } + + if (!buffer_is_zero(&vmsa_check, sizeof(vmsa_check))) { + error_setg(errp, + "%s: The VMSA contains fields that are not " + "synchronized with KVM. Continuing would result in " + "either unpredictable guest behavior, or a " + "mismatched launch measurement.", + __func__); + return -1; + } + return 0; +} + static int sev_set_cpu_context(uint16_t cpu_index, const void *ctx, uint32_t ctx_len, hwaddr gpa, Error **errp) { @@ -1491,18 +1593,26 @@ sev_snp_launch_finish(SevCommonState *sev_common) struct kvm_sev_snp_launch_finish *finish = &sev_snp->kvm_finish_conf; /* - * To boot the SNP guest, the hypervisor is required to populate the CPUID - * and Secrets page before finalizing the launch flow. The location of - * the secrets and CPUID page is available through the OVMF metadata GUID. + * Populate all the metadata pages if not using an IGVM file. In the case + * where an IGVM file is provided it will be used to configure the metadata + * pages directly. */ - metadata = pc_system_get_ovmf_sev_metadata_ptr(); - if (metadata == NULL) { - error_report("%s: Failed to locate SEV metadata header", __func__); - exit(1); - } + if (!X86_MACHINE(qdev_get_machine())->igvm) { + /* + * To boot the SNP guest, the hypervisor is required to populate the + * CPUID and Secrets page before finalizing the launch flow. The + * location of the secrets and CPUID page is available through the + * OVMF metadata GUID. + */ + metadata = pc_system_get_ovmf_sev_metadata_ptr(); + if (metadata == NULL) { + error_report("%s: Failed to locate SEV metadata header", __func__); + exit(1); + } - /* Populate all the metadata pages */ - snp_populate_metadata_pages(sev_snp, metadata); + /* Populate all the metadata pages */ + snp_populate_metadata_pages(sev_snp, metadata); + } QTAILQ_FOREACH(data, &launch_update, next) { ret = sev_snp_launch_update(sev_snp, data); @@ -2290,6 +2400,124 @@ static void sev_common_set_kernel_hashes(Object *obj, bool value, Error **errp) SEV_COMMON(obj)->kernel_hashes = value; } +static bool cgs_check_support(ConfidentialGuestPlatformType platform, + uint16_t platform_version, uint8_t highest_vtl, + uint64_t shared_gpa_boundary) +{ + return (((platform == CGS_PLATFORM_SEV_SNP) && sev_snp_enabled()) || + ((platform == CGS_PLATFORM_SEV_ES) && sev_es_enabled()) || + ((platform == CGS_PLATFORM_SEV) && sev_enabled())); +} + +static int cgs_set_guest_state(hwaddr gpa, uint8_t *ptr, uint64_t len, + ConfidentialGuestPageType memory_type, + uint16_t cpu_index, Error **errp) +{ + SevCommonState *sev_common = SEV_COMMON(MACHINE(qdev_get_machine())->cgs); + SevCommonStateClass *klass = SEV_COMMON_GET_CLASS(sev_common); + + if (!sev_enabled()) { + error_setg(errp, "%s: attempt to configure guest memory, but SEV " + "is not enabled", __func__); + return -1; + } + + switch (memory_type) { + case CGS_PAGE_TYPE_NORMAL: + case CGS_PAGE_TYPE_ZERO: + return klass->launch_update_data(sev_common, gpa, ptr, len, errp); + + case CGS_PAGE_TYPE_VMSA: + if (!sev_es_enabled()) { + error_setg(errp, + "%s: attempt to configure initial VMSA, but SEV-ES " + "is not supported", + __func__); + return -1; + } + if (check_vmsa_supported(gpa, (const struct sev_es_save_area *)ptr, + errp) < 0) { + return -1; + } + return sev_set_cpu_context(cpu_index, ptr, len, gpa, errp); + + case CGS_PAGE_TYPE_UNMEASURED: + if (sev_snp_enabled()) { + return snp_launch_update_data( + gpa, ptr, len, KVM_SEV_SNP_PAGE_TYPE_UNMEASURED, errp); + } + /* No action required if not SEV-SNP */ + return 0; + + case CGS_PAGE_TYPE_SECRETS: + if (!sev_snp_enabled()) { + error_setg(errp, + "%s: attempt to configure secrets page, but SEV-SNP " + "is not supported", + __func__); + return -1; + } + return snp_launch_update_data(gpa, ptr, len, + KVM_SEV_SNP_PAGE_TYPE_SECRETS, errp); + + case CGS_PAGE_TYPE_REQUIRED_MEMORY: + if (kvm_convert_memory(gpa, len, true) < 0) { + error_setg( + errp, + "%s: failed to configure required memory. gpa: %lX, type: %d", + __func__, gpa, memory_type); + return -1; + } + return 0; + + case CGS_PAGE_TYPE_CPUID: + if (!sev_snp_enabled()) { + error_setg(errp, + "%s: attempt to configure CPUID page, but SEV-SNP " + "is not supported", + __func__); + return -1; + } + return snp_launch_update_cpuid(gpa, ptr, len, errp); + } + error_setg(errp, "%s: failed to update guest. gpa: %lX, type: %d", __func__, + gpa, memory_type); + return -1; +} + +static int cgs_get_mem_map_entry(int index, + ConfidentialGuestMemoryMapEntry *entry, + Error **errp) +{ + struct e820_entry *table; + int num_entries; + + num_entries = e820_get_table(&table); + if ((index < 0) || (index >= num_entries)) { + return 1; + } + entry->gpa = table[index].address; + entry->size = table[index].length; + switch (table[index].type) { + case E820_RAM: + entry->type = CGS_MEM_RAM; + break; + case E820_RESERVED: + entry->type = CGS_MEM_RESERVED; + break; + case E820_ACPI: + entry->type = CGS_MEM_ACPI; + break; + case E820_NVS: + entry->type = CGS_MEM_NVS; + break; + case E820_UNUSABLE: + entry->type = CGS_MEM_UNUSABLE; + break; + } + return 0; +} + static void sev_common_class_init(ObjectClass *oc, const void *data) { @@ -2313,6 +2541,8 @@ static void sev_common_instance_init(Object *obj) { SevCommonState *sev_common = SEV_COMMON(obj); + ConfidentialGuestSupportClass *cgs = + CONFIDENTIAL_GUEST_SUPPORT_GET_CLASS(obj); sev_common->kvm_type = -1; @@ -2323,6 +2553,10 @@ sev_common_instance_init(Object *obj) object_property_add_uint32_ptr(obj, "reduced-phys-bits", &sev_common->reduced_phys_bits, OBJ_PROP_FLAG_READWRITE); + cgs->check_support = cgs_check_support; + cgs->set_guest_state = cgs_set_guest_state; + cgs->get_mem_map_entry = cgs_get_mem_map_entry; + QTAILQ_INIT(&sev_common->launch_vmsa); } diff --git a/target/i386/sev.h b/target/i386/sev.h index 38caa849f5..d2eb06db32 100644 --- a/target/i386/sev.h +++ b/target/i386/sev.h @@ -44,6 +44,8 @@ bool sev_snp_enabled(void); #define SEV_SNP_POLICY_SMT 0x10000 #define SEV_SNP_POLICY_DBG 0x80000 +#define SVM_SEV_FEAT_SNP_ACTIVE 1 + typedef struct SevKernelLoaderContext { char *setup_data; size_t setup_size; |