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authorLinus Torvalds <torvalds@linux-foundation.org>2024-11-19 12:21:35 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2024-11-19 12:21:35 -0800
commit55db8eb4565f943dc0ebd1327cbe3d9d684f74e8 (patch)
tree2c51b8d22b3ba379889c50137595b18f38acd93a /arch/x86/include
parent9db8b240704cf66b8c9caaad586034399ac39641 (diff)
parent8bca85cc1eb72e21a3544ab32e546a819d8674ca (diff)
Merge tag 'x86_sev_for_v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 SEV updates from Borislav Petkov: - Do the proper memory conversion of guest memory in order to be able to kexec kernels in SNP guests along with other adjustments and cleanups to that effect - Start converting and moving functionality from the sev-guest driver into core code with the purpose of supporting the secure TSC SNP feature where the hypervisor cannot influence the TSC exposed to the guest anymore - Add a "nosnp" cmdline option in order to be able to disable SNP support in the hypervisor and thus free-up resources which are not going to be used - Cleanups [ Reminding myself about the endless TLA's again: SEV is the AMD Secure Encrypted Virtualization - Linus ] * tag 'x86_sev_for_v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/sev: Cleanup vc_handle_msr() x86/sev: Convert shared memory back to private on kexec x86/mm: Refactor __set_clr_pte_enc() x86/boot: Skip video memory access in the decompressor for SEV-ES/SNP virt: sev-guest: Carve out SNP message context structure virt: sev-guest: Reduce the scope of SNP command mutex virt: sev-guest: Consolidate SNP guest messaging parameters to a struct x86/sev: Cache the secrets page address x86/sev: Handle failures from snp_init() virt: sev-guest: Use AES GCM crypto library x86/virt: Provide "nosnp" boot option for sev kernel command line x86/virt: Move SEV-specific parsing into arch/x86/virt/svm
Diffstat (limited to 'arch/x86/include')
-rw-r--r--arch/x86/include/asm/sev-common.h27
-rw-r--r--arch/x86/include/asm/sev.h67
2 files changed, 92 insertions, 2 deletions
diff --git a/arch/x86/include/asm/sev-common.h b/arch/x86/include/asm/sev-common.h
index 98726c2b04f8..50f5666938c0 100644
--- a/arch/x86/include/asm/sev-common.h
+++ b/arch/x86/include/asm/sev-common.h
@@ -220,4 +220,31 @@ struct snp_psc_desc {
#define GHCB_ERR_INVALID_INPUT 5
#define GHCB_ERR_INVALID_EVENT 6
+struct sev_config {
+ __u64 debug : 1,
+
+ /*
+ * Indicates when the per-CPU GHCB has been created and registered
+ * and thus can be used by the BSP instead of the early boot GHCB.
+ *
+ * For APs, the per-CPU GHCB is created before they are started
+ * and registered upon startup, so this flag can be used globally
+ * for the BSP and APs.
+ */
+ ghcbs_initialized : 1,
+
+ /*
+ * Indicates when the per-CPU SVSM CA is to be used instead of the
+ * boot SVSM CA.
+ *
+ * For APs, the per-CPU SVSM CA is created as part of the AP
+ * bringup, so this flag can be used globally for the BSP and APs.
+ */
+ use_cas : 1,
+
+ __reserved : 61;
+};
+
+extern struct sev_config sev_cfg;
+
#endif
diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h
index ee34ab00a8d6..91f08af31078 100644
--- a/arch/x86/include/asm/sev.h
+++ b/arch/x86/include/asm/sev.h
@@ -120,6 +120,9 @@ struct snp_req_data {
};
#define MAX_AUTHTAG_LEN 32
+#define AUTHTAG_LEN 16
+#define AAD_LEN 48
+#define MSG_HDR_VER 1
/* See SNP spec SNP_GUEST_REQUEST section for the structure */
enum msg_type {
@@ -171,6 +174,19 @@ struct sev_guest_platform_data {
u64 secrets_gpa;
};
+struct snp_guest_req {
+ void *req_buf;
+ size_t req_sz;
+
+ void *resp_buf;
+ size_t resp_sz;
+
+ u64 exit_code;
+ unsigned int vmpck_id;
+ u8 msg_version;
+ u8 msg_type;
+};
+
/*
* The secrets page contains 96-bytes of reserved field that can be used by
* the guest OS. The guest OS uses the area to save the message sequence
@@ -218,6 +234,27 @@ struct snp_secrets_page {
u8 rsvd4[3744];
} __packed;
+struct snp_msg_desc {
+ /* request and response are in unencrypted memory */
+ struct snp_guest_msg *request, *response;
+
+ /*
+ * Avoid information leakage by double-buffering shared messages
+ * in fields that are in regular encrypted memory.
+ */
+ struct snp_guest_msg secret_request, secret_response;
+
+ struct snp_secrets_page *secrets;
+ struct snp_req_data input;
+
+ void *certs_data;
+
+ struct aesgcm_ctx *ctx;
+
+ u32 *os_area_msg_seqno;
+ u8 *vmpck;
+};
+
/*
* The SVSM Calling Area (CA) related structures.
*/
@@ -285,6 +322,22 @@ struct svsm_attest_call {
u8 rsvd[4];
};
+/* PTE descriptor used for the prepare_pte_enc() operations. */
+struct pte_enc_desc {
+ pte_t *kpte;
+ int pte_level;
+ bool encrypt;
+ /* pfn of the kpte above */
+ unsigned long pfn;
+ /* physical address of @pfn */
+ unsigned long pa;
+ /* virtual address of @pfn */
+ void *va;
+ /* memory covered by the pte */
+ unsigned long size;
+ pgprot_t new_pgprot;
+};
+
/*
* SVSM protocol structure
*/
@@ -392,13 +445,18 @@ void snp_set_wakeup_secondary_cpu(void);
bool snp_init(struct boot_params *bp);
void __noreturn snp_abort(void);
void snp_dmi_setup(void);
-int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, struct snp_guest_request_ioctl *rio);
+int snp_issue_guest_request(struct snp_guest_req *req, struct snp_req_data *input,
+ struct snp_guest_request_ioctl *rio);
int snp_issue_svsm_attest_req(u64 call_id, struct svsm_call *call, struct svsm_attest_call *input);
void snp_accept_memory(phys_addr_t start, phys_addr_t end);
u64 snp_get_unsupported_features(u64 status);
u64 sev_get_status(void);
void sev_show_status(void);
void snp_update_svsm_ca(void);
+int prepare_pte_enc(struct pte_enc_desc *d);
+void set_pte_enc_mask(pte_t *kpte, unsigned long pfn, pgprot_t new_prot);
+void snp_kexec_finish(void);
+void snp_kexec_begin(void);
#else /* !CONFIG_AMD_MEM_ENCRYPT */
@@ -422,7 +480,8 @@ static inline void snp_set_wakeup_secondary_cpu(void) { }
static inline bool snp_init(struct boot_params *bp) { return false; }
static inline void snp_abort(void) { }
static inline void snp_dmi_setup(void) { }
-static inline int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, struct snp_guest_request_ioctl *rio)
+static inline int snp_issue_guest_request(struct snp_guest_req *req, struct snp_req_data *input,
+ struct snp_guest_request_ioctl *rio)
{
return -ENOTTY;
}
@@ -435,6 +494,10 @@ static inline u64 snp_get_unsupported_features(u64 status) { return 0; }
static inline u64 sev_get_status(void) { return 0; }
static inline void sev_show_status(void) { }
static inline void snp_update_svsm_ca(void) { }
+static inline int prepare_pte_enc(struct pte_enc_desc *d) { return 0; }
+static inline void set_pte_enc_mask(pte_t *kpte, unsigned long pfn, pgprot_t new_prot) { }
+static inline void snp_kexec_finish(void) { }
+static inline void snp_kexec_begin(void) { }
#endif /* CONFIG_AMD_MEM_ENCRYPT */