diff options
| -rw-r--r-- | arch/x86/boot/compressed/sev.c | 197 | ||||
| -rw-r--r-- | arch/x86/include/asm/sev.h | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/sev.c | 6 | ||||
| -rw-r--r-- | drivers/virt/coco/sev-guest/sev-guest.c | 28 |
4 files changed, 113 insertions, 120 deletions
diff --git a/arch/x86/boot/compressed/sev.c b/arch/x86/boot/compressed/sev.c index ec71846d28c9..0457a9d7e515 100644 --- a/arch/x86/boot/compressed/sev.c +++ b/arch/x86/boot/compressed/sev.c @@ -335,26 +335,6 @@ finish: sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_GEN_REQ); } -static void enforce_vmpl0(void) -{ - u64 attrs; - int err; - - /* - * RMPADJUST modifies RMP permissions of a lesser-privileged (numerically - * higher) privilege level. Here, clear the VMPL1 permission mask of the - * GHCB page. If the guest is not running at VMPL0, this will fail. - * - * If the guest is running at VMPL0, it will succeed. Even if that operation - * modifies permission bits, it is still ok to do so currently because Linux - * SNP guests are supported only on VMPL0 so VMPL1 or higher permission masks - * changing is a don't-care. - */ - attrs = 1; - if (rmpadjust((unsigned long)&boot_ghcb_page, RMP_PG_SIZE_4K, attrs)) - sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_NOT_VMPL0); -} - /* * SNP_FEATURES_IMPL_REQ is the mask of SNP features that will need * guest side implementation for proper functioning of the guest. If any @@ -413,6 +393,85 @@ void snp_check_features(void) } } +/* Search for Confidential Computing blob in the EFI config table. */ +static struct cc_blob_sev_info *find_cc_blob_efi(struct boot_params *bp) +{ + unsigned long cfg_table_pa; + unsigned int cfg_table_len; + int ret; + + ret = efi_get_conf_table(bp, &cfg_table_pa, &cfg_table_len); + if (ret) + return NULL; + + return (struct cc_blob_sev_info *)efi_find_vendor_table(bp, cfg_table_pa, + cfg_table_len, + EFI_CC_BLOB_GUID); +} + +/* + * Initial set up of SNP relies on information provided by the + * Confidential Computing blob, which can be passed to the boot kernel + * by firmware/bootloader in the following ways: + * + * - via an entry in the EFI config table + * - via a setup_data structure, as defined by the Linux Boot Protocol + * + * Scan for the blob in that order. + */ +static struct cc_blob_sev_info *find_cc_blob(struct boot_params *bp) +{ + struct cc_blob_sev_info *cc_info; + + cc_info = find_cc_blob_efi(bp); + if (cc_info) + goto found_cc_info; + + cc_info = find_cc_blob_setup_data(bp); + if (!cc_info) + return NULL; + +found_cc_info: + if (cc_info->magic != CC_BLOB_SEV_HDR_MAGIC) + sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED); + + return cc_info; +} + +/* + * Indicate SNP based on presence of SNP-specific CC blob. Subsequent checks + * will verify the SNP CPUID/MSR bits. + */ +static bool early_snp_init(struct boot_params *bp) +{ + struct cc_blob_sev_info *cc_info; + + if (!bp) + return false; + + cc_info = find_cc_blob(bp); + if (!cc_info) + return false; + + /* + * If a SNP-specific Confidential Computing blob is present, then + * firmware/bootloader have indicated SNP support. Verifying this + * involves CPUID checks which will be more reliable if the SNP + * CPUID table is used. See comments over snp_setup_cpuid_table() for + * more details. + */ + setup_cpuid_table(cc_info); + + /* + * Pass run-time kernel a pointer to CC info via boot_params so EFI + * config table doesn't need to be searched again during early startup + * phase. + */ + bp->cc_blob_address = (u32)(unsigned long)cc_info; + + return true; +} + /* * sev_check_cpu_support - Check for SEV support in the CPU capabilities * @@ -463,7 +522,7 @@ void sev_enable(struct boot_params *bp) bp->cc_blob_address = 0; /* - * Do an initial SEV capability check before snp_init() which + * Do an initial SEV capability check before early_snp_init() which * loads the CPUID page and the same checks afterwards are done * without the hypervisor and are trustworthy. * @@ -478,7 +537,7 @@ void sev_enable(struct boot_params *bp) * Setup/preliminary detection of SNP. This will be sanity-checked * against CPUID/MSR values later. */ - snp = snp_init(bp); + snp = early_snp_init(bp); /* Now repeat the checks with the SNP CPUID table. */ @@ -509,7 +568,20 @@ void sev_enable(struct boot_params *bp) if (!(get_hv_features() & GHCB_HV_FT_SNP)) sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED); - enforce_vmpl0(); + /* + * Enforce running at VMPL0. + * + * RMPADJUST modifies RMP permissions of a lesser-privileged (numerically + * higher) privilege level. Here, clear the VMPL1 permission mask of the + * GHCB page. If the guest is not running at VMPL0, this will fail. + * + * If the guest is running at VMPL0, it will succeed. Even if that operation + * modifies permission bits, it is still ok to do so currently because Linux + * SNP guests running at VMPL0 only run at VMPL0, so VMPL1 or higher + * permission mask changes are a don't-care. + */ + if (rmpadjust((unsigned long)&boot_ghcb_page, RMP_PG_SIZE_4K, 1)) + sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_NOT_VMPL0); } if (snp && !(sev_status & MSR_AMD64_SEV_SNP_ENABLED)) @@ -535,85 +607,6 @@ u64 sev_get_status(void) return m.q; } -/* Search for Confidential Computing blob in the EFI config table. */ -static struct cc_blob_sev_info *find_cc_blob_efi(struct boot_params *bp) -{ - unsigned long cfg_table_pa; - unsigned int cfg_table_len; - int ret; - - ret = efi_get_conf_table(bp, &cfg_table_pa, &cfg_table_len); - if (ret) - return NULL; - - return (struct cc_blob_sev_info *)efi_find_vendor_table(bp, cfg_table_pa, - cfg_table_len, - EFI_CC_BLOB_GUID); -} - -/* - * Initial set up of SNP relies on information provided by the - * Confidential Computing blob, which can be passed to the boot kernel - * by firmware/bootloader in the following ways: - * - * - via an entry in the EFI config table - * - via a setup_data structure, as defined by the Linux Boot Protocol - * - * Scan for the blob in that order. - */ -static struct cc_blob_sev_info *find_cc_blob(struct boot_params *bp) -{ - struct cc_blob_sev_info *cc_info; - - cc_info = find_cc_blob_efi(bp); - if (cc_info) - goto found_cc_info; - - cc_info = find_cc_blob_setup_data(bp); - if (!cc_info) - return NULL; - -found_cc_info: - if (cc_info->magic != CC_BLOB_SEV_HDR_MAGIC) - sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED); - - return cc_info; -} - -/* - * Indicate SNP based on presence of SNP-specific CC blob. Subsequent checks - * will verify the SNP CPUID/MSR bits. - */ -bool snp_init(struct boot_params *bp) -{ - struct cc_blob_sev_info *cc_info; - - if (!bp) - return false; - - cc_info = find_cc_blob(bp); - if (!cc_info) - return false; - - /* - * If a SNP-specific Confidential Computing blob is present, then - * firmware/bootloader have indicated SNP support. Verifying this - * involves CPUID checks which will be more reliable if the SNP - * CPUID table is used. See comments over snp_setup_cpuid_table() for - * more details. - */ - setup_cpuid_table(cc_info); - - /* - * Pass run-time kernel a pointer to CC info via boot_params so EFI - * config table doesn't need to be searched again during early startup - * phase. - */ - bp->cc_blob_address = (u32)(unsigned long)cc_info; - - return true; -} - void sev_prep_identity_maps(unsigned long top_level_pgt) { /* diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h index 93ed60080cfe..ca20cc4e5826 100644 --- a/arch/x86/include/asm/sev.h +++ b/arch/x86/include/asm/sev.h @@ -140,7 +140,7 @@ struct secrets_os_area { #define VMPCK_KEY_LEN 32 /* See the SNP spec version 0.9 for secrets page format */ -struct snp_secrets_page_layout { +struct snp_secrets_page { u32 version; u32 imien : 1, rsvd1 : 31; diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c index 995f94467101..3342ed58e168 100644 --- a/arch/x86/kernel/sev.c +++ b/arch/x86/kernel/sev.c @@ -648,7 +648,7 @@ static u64 __init get_secrets_page(void) static u64 __init get_snp_jump_table_addr(void) { - struct snp_secrets_page_layout *layout; + struct snp_secrets_page *secrets; void __iomem *mem; u64 pa, addr; @@ -662,9 +662,9 @@ static u64 __init get_snp_jump_table_addr(void) return 0; } - layout = (__force struct snp_secrets_page_layout *)mem; + secrets = (__force struct snp_secrets_page *)mem; - addr = layout->os_area.ap_jump_table_pa; + addr = secrets->os_area.ap_jump_table_pa; iounmap(mem); return addr; diff --git a/drivers/virt/coco/sev-guest/sev-guest.c b/drivers/virt/coco/sev-guest/sev-guest.c index 87f241825bc3..654290a8e1ba 100644 --- a/drivers/virt/coco/sev-guest/sev-guest.c +++ b/drivers/virt/coco/sev-guest/sev-guest.c @@ -59,7 +59,7 @@ struct snp_guest_dev { */ struct snp_guest_msg secret_request, secret_response; - struct snp_secrets_page_layout *layout; + struct snp_secrets_page *secrets; struct snp_req_data input; union { struct snp_report_req report; @@ -743,26 +743,26 @@ static const struct file_operations snp_guest_fops = { .unlocked_ioctl = snp_guest_ioctl, }; -static u8 *get_vmpck(int id, struct snp_secrets_page_layout *layout, u32 **seqno) +static u8 *get_vmpck(int id, struct snp_secrets_page *secrets, u32 **seqno) { u8 *key = NULL; switch (id) { case 0: - *seqno = &layout->os_area.msg_seqno_0; - key = layout->vmpck0; + *seqno = &secrets->os_area.msg_seqno_0; + key = secrets->vmpck0; break; case 1: - *seqno = &layout->os_area.msg_seqno_1; - key = layout->vmpck1; + *seqno = &secrets->os_area.msg_seqno_1; + key = secrets->vmpck1; break; case 2: - *seqno = &layout->os_area.msg_seqno_2; - key = layout->vmpck2; + *seqno = &secrets->os_area.msg_seqno_2; + key = secrets->vmpck2; break; case 3: - *seqno = &layout->os_area.msg_seqno_3; - key = layout->vmpck3; + *seqno = &secrets->os_area.msg_seqno_3; + key = secrets->vmpck3; break; default: break; @@ -897,8 +897,8 @@ static void unregister_sev_tsm(void *data) static int __init sev_guest_probe(struct platform_device *pdev) { - struct snp_secrets_page_layout *layout; struct sev_guest_platform_data *data; + struct snp_secrets_page *secrets; struct device *dev = &pdev->dev; struct snp_guest_dev *snp_dev; struct miscdevice *misc; @@ -916,7 +916,7 @@ static int __init sev_guest_probe(struct platform_device *pdev) if (!mapping) return -ENODEV; - layout = (__force void *)mapping; + secrets = (__force void *)mapping; ret = -ENOMEM; snp_dev = devm_kzalloc(&pdev->dev, sizeof(struct snp_guest_dev), GFP_KERNEL); @@ -924,7 +924,7 @@ static int __init sev_guest_probe(struct platform_device *pdev) goto e_unmap; ret = -EINVAL; - snp_dev->vmpck = get_vmpck(vmpck_id, layout, &snp_dev->os_area_msg_seqno); + snp_dev->vmpck = get_vmpck(vmpck_id, secrets, &snp_dev->os_area_msg_seqno); if (!snp_dev->vmpck) { dev_err(dev, "invalid vmpck id %d\n", vmpck_id); goto e_unmap; @@ -938,7 +938,7 @@ static int __init sev_guest_probe(struct platform_device *pdev) platform_set_drvdata(pdev, snp_dev); snp_dev->dev = dev; - snp_dev->layout = layout; + snp_dev->secrets = secrets; /* Allocate the shared page used for the request and response message. */ snp_dev->request = alloc_shared_pages(dev, sizeof(struct snp_guest_msg)); |