# SPDX-License-Identifier: GPL-2.0
-obj-y += core.o noinstr.o vc-handle.o
+obj-y += core.o noinstr.o vc-handle.o svsm.o
# Clang 14 and older may fail to respect __no_sanitize_undefined when inlining
UBSAN_SANITIZE_noinstr.o := n
u64 sev_secrets_pa __ro_after_init;
SYM_PIC_ALIAS(sev_secrets_pa);
-/* For early boot SVSM communication */
-struct svsm_ca boot_svsm_ca_page __aligned(PAGE_SIZE);
-SYM_PIC_ALIAS(boot_svsm_ca_page);
-
-/*
- * SVSM related information:
- * During boot, the page tables are set up as identity mapped and later
- * changed to use kernel virtual addresses. Maintain separate virtual and
- * physical addresses for the CAA to allow SVSM functions to be used during
- * early boot, both with identity mapped virtual addresses and proper kernel
- * virtual addresses.
- */
-u64 boot_svsm_caa_pa __ro_after_init;
-SYM_PIC_ALIAS(boot_svsm_caa_pa);
-
-DEFINE_PER_CPU(struct svsm_ca *, svsm_caa);
-DEFINE_PER_CPU(u64, svsm_caa_pa);
-
-static inline struct svsm_ca *svsm_get_caa(void)
-{
- if (sev_cfg.use_cas)
- return this_cpu_read(svsm_caa);
- else
- return rip_rel_ptr(&boot_svsm_ca_page);
-}
-
-static inline u64 svsm_get_caa_pa(void)
-{
- if (sev_cfg.use_cas)
- return this_cpu_read(svsm_caa_pa);
- else
- return boot_svsm_caa_pa;
-}
-
/* AP INIT values as documented in the APM2 section "Processor Initialization State" */
#define AP_INIT_CS_LIMIT 0xffff
#define AP_INIT_DS_LIMIT 0xffff
return ret;
}
-static int svsm_perform_ghcb_protocol(struct ghcb *ghcb, struct svsm_call *call)
-{
- struct es_em_ctxt ctxt;
- u8 pending = 0;
-
- vc_ghcb_invalidate(ghcb);
-
- /*
- * Fill in protocol and format specifiers. This can be called very early
- * in the boot, so use rip-relative references as needed.
- */
- ghcb->protocol_version = ghcb_version;
- ghcb->ghcb_usage = GHCB_DEFAULT_USAGE;
-
- ghcb_set_sw_exit_code(ghcb, SVM_VMGEXIT_SNP_RUN_VMPL);
- ghcb_set_sw_exit_info_1(ghcb, 0);
- ghcb_set_sw_exit_info_2(ghcb, 0);
-
- sev_es_wr_ghcb_msr(__pa(ghcb));
-
- svsm_issue_call(call, &pending);
-
- if (pending)
- return -EINVAL;
-
- switch (verify_exception_info(ghcb, &ctxt)) {
- case ES_OK:
- break;
- case ES_EXCEPTION:
- vc_forward_exception(&ctxt);
- fallthrough;
- default:
- return -EINVAL;
- }
-
- return svsm_process_result_codes(call);
-}
-
-static int svsm_perform_call_protocol(struct svsm_call *call)
-{
- struct ghcb_state state;
- unsigned long flags;
- struct ghcb *ghcb;
- int ret;
-
- flags = native_local_irq_save();
-
- if (sev_cfg.ghcbs_initialized)
- ghcb = __sev_get_ghcb(&state);
- else if (boot_ghcb)
- ghcb = boot_ghcb;
- else
- ghcb = NULL;
-
- do {
- ret = ghcb ? svsm_perform_ghcb_protocol(ghcb, call)
- : __pi_svsm_perform_msr_protocol(call);
- } while (ret == -EAGAIN);
-
- if (sev_cfg.ghcbs_initialized)
- __sev_put_ghcb(&state);
-
- native_local_irq_restore(flags);
-
- return ret;
-}
-
-static inline void __pval_terminate(u64 pfn, bool action, unsigned int page_size,
- int ret, u64 svsm_ret)
-{
- WARN(1, "PVALIDATE failure: pfn: 0x%llx, action: %u, size: %u, ret: %d, svsm_ret: 0x%llx\n",
- pfn, action, page_size, ret, svsm_ret);
-
- sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PVALIDATE);
-}
-
-static void svsm_pval_terminate(struct svsm_pvalidate_call *pc, int ret, u64 svsm_ret)
-{
- unsigned int page_size;
- bool action;
- u64 pfn;
-
- pfn = pc->entry[pc->cur_index].pfn;
- action = pc->entry[pc->cur_index].action;
- page_size = pc->entry[pc->cur_index].page_size;
-
- __pval_terminate(pfn, action, page_size, ret, svsm_ret);
-}
-
static void pval_pages(struct snp_psc_desc *desc)
{
struct psc_entry *e;
}
}
-static u64 svsm_build_ca_from_pfn_range(u64 pfn, u64 pfn_end, bool action,
- struct svsm_pvalidate_call *pc)
-{
- struct svsm_pvalidate_entry *pe;
-
- /* Nothing in the CA yet */
- pc->num_entries = 0;
- pc->cur_index = 0;
-
- pe = &pc->entry[0];
-
- while (pfn < pfn_end) {
- pe->page_size = RMP_PG_SIZE_4K;
- pe->action = action;
- pe->ignore_cf = 0;
- pe->rsvd = 0;
- pe->pfn = pfn;
-
- pe++;
- pfn++;
-
- pc->num_entries++;
- if (pc->num_entries == SVSM_PVALIDATE_MAX_COUNT)
- break;
- }
-
- return pfn;
-}
-
-static int svsm_build_ca_from_psc_desc(struct snp_psc_desc *desc, unsigned int desc_entry,
- struct svsm_pvalidate_call *pc)
-{
- struct svsm_pvalidate_entry *pe;
- struct psc_entry *e;
-
- /* Nothing in the CA yet */
- pc->num_entries = 0;
- pc->cur_index = 0;
-
- pe = &pc->entry[0];
- e = &desc->entries[desc_entry];
-
- while (desc_entry <= desc->hdr.end_entry) {
- pe->page_size = e->pagesize ? RMP_PG_SIZE_2M : RMP_PG_SIZE_4K;
- pe->action = e->operation == SNP_PAGE_STATE_PRIVATE;
- pe->ignore_cf = 0;
- pe->rsvd = 0;
- pe->pfn = e->gfn;
-
- pe++;
- e++;
-
- desc_entry++;
- pc->num_entries++;
- if (pc->num_entries == SVSM_PVALIDATE_MAX_COUNT)
- break;
- }
-
- return desc_entry;
-}
-
-static void svsm_pval_pages(struct snp_psc_desc *desc)
-{
- struct svsm_pvalidate_entry pv_4k[VMGEXIT_PSC_MAX_ENTRY];
- unsigned int i, pv_4k_count = 0;
- struct svsm_pvalidate_call *pc;
- struct svsm_call call = {};
- unsigned long flags;
- bool action;
- u64 pc_pa;
- int ret;
-
- /*
- * This can be called very early in the boot, use native functions in
- * order to avoid paravirt issues.
- */
- flags = native_local_irq_save();
-
- /*
- * The SVSM calling area (CA) can support processing 510 entries at a
- * time. Loop through the Page State Change descriptor until the CA is
- * full or the last entry in the descriptor is reached, at which time
- * the SVSM is invoked. This repeats until all entries in the descriptor
- * are processed.
- */
- call.caa = svsm_get_caa();
-
- pc = (struct svsm_pvalidate_call *)call.caa->svsm_buffer;
- pc_pa = svsm_get_caa_pa() + offsetof(struct svsm_ca, svsm_buffer);
-
- /* Protocol 0, Call ID 1 */
- call.rax = SVSM_CORE_CALL(SVSM_CORE_PVALIDATE);
- call.rcx = pc_pa;
-
- for (i = 0; i <= desc->hdr.end_entry;) {
- i = svsm_build_ca_from_psc_desc(desc, i, pc);
-
- do {
- ret = svsm_perform_call_protocol(&call);
- if (!ret)
- continue;
-
- /*
- * Check if the entry failed because of an RMP mismatch (a
- * PVALIDATE at 2M was requested, but the page is mapped in
- * the RMP as 4K).
- */
-
- if (call.rax_out == SVSM_PVALIDATE_FAIL_SIZEMISMATCH &&
- pc->entry[pc->cur_index].page_size == RMP_PG_SIZE_2M) {
- /* Save this entry for post-processing at 4K */
- pv_4k[pv_4k_count++] = pc->entry[pc->cur_index];
-
- /* Skip to the next one unless at the end of the list */
- pc->cur_index++;
- if (pc->cur_index < pc->num_entries)
- ret = -EAGAIN;
- else
- ret = 0;
- }
- } while (ret == -EAGAIN);
-
- if (ret)
- svsm_pval_terminate(pc, ret, call.rax_out);
- }
-
- /* Process any entries that failed to be validated at 2M and validate them at 4K */
- for (i = 0; i < pv_4k_count; i++) {
- u64 pfn, pfn_end;
-
- action = pv_4k[i].action;
- pfn = pv_4k[i].pfn;
- pfn_end = pfn + 512;
-
- while (pfn < pfn_end) {
- pfn = svsm_build_ca_from_pfn_range(pfn, pfn_end, action, pc);
-
- ret = svsm_perform_call_protocol(&call);
- if (ret)
- svsm_pval_terminate(pc, ret, call.rax_out);
- }
- }
-
- native_local_irq_restore(flags);
-}
-
static void pvalidate_pages(struct snp_psc_desc *desc)
{
struct psc_entry *e;
}
arch_initcall(report_snp_info);
-static void update_attest_input(struct svsm_call *call, struct svsm_attest_call *input)
-{
- /* If (new) lengths have been returned, propagate them up */
- if (call->rcx_out != call->rcx)
- input->manifest_buf.len = call->rcx_out;
-
- if (call->rdx_out != call->rdx)
- input->certificates_buf.len = call->rdx_out;
-
- if (call->r8_out != call->r8)
- input->report_buf.len = call->r8_out;
-}
-
-int snp_issue_svsm_attest_req(u64 call_id, struct svsm_call *call,
- struct svsm_attest_call *input)
-{
- struct svsm_attest_call *ac;
- unsigned long flags;
- u64 attest_call_pa;
- int ret;
-
- if (!snp_vmpl)
- return -EINVAL;
-
- local_irq_save(flags);
-
- call->caa = svsm_get_caa();
-
- ac = (struct svsm_attest_call *)call->caa->svsm_buffer;
- attest_call_pa = svsm_get_caa_pa() + offsetof(struct svsm_ca, svsm_buffer);
-
- *ac = *input;
-
- /*
- * Set input registers for the request and set RDX and R8 to known
- * values in order to detect length values being returned in them.
- */
- call->rax = call_id;
- call->rcx = attest_call_pa;
- call->rdx = -1;
- call->r8 = -1;
- ret = svsm_perform_call_protocol(call);
- update_attest_input(call, input);
-
- local_irq_restore(flags);
-
- return ret;
-}
-EXPORT_SYMBOL_GPL(snp_issue_svsm_attest_req);
-
static int snp_issue_guest_request(struct snp_guest_req *req)
{
struct snp_req_data *input = &req->input;
return ret;
}
-/**
- * snp_svsm_vtpm_probe() - Probe if SVSM provides a vTPM device
- *
- * Check that there is SVSM and that it supports at least TPM_SEND_COMMAND
- * which is the only request used so far.
- *
- * Return: true if the platform provides a vTPM SVSM device, false otherwise.
- */
-static bool snp_svsm_vtpm_probe(void)
-{
- struct svsm_call call = {};
-
- /* The vTPM device is available only if a SVSM is present */
- if (!snp_vmpl)
- return false;
-
- call.caa = svsm_get_caa();
- call.rax = SVSM_VTPM_CALL(SVSM_VTPM_QUERY);
-
- if (svsm_perform_call_protocol(&call))
- return false;
-
- /* Check platform commands contains TPM_SEND_COMMAND - platform command 8 */
- return call.rcx_out & BIT_ULL(8);
-}
-
-/**
- * snp_svsm_vtpm_send_command() - Execute a vTPM operation on SVSM
- * @buffer: A buffer used to both send the command and receive the response.
- *
- * Execute a SVSM_VTPM_CMD call as defined by
- * "Secure VM Service Module for SEV-SNP Guests" Publication # 58019 Revision: 1.00
- *
- * All command request/response buffers have a common structure as specified by
- * the following table:
- * Byte Size In/Out Description
- * Offset (Bytes)
- * 0x000 4 In Platform command
- * Out Platform command response size
- *
- * Each command can build upon this common request/response structure to create
- * a structure specific to the command. See include/linux/tpm_svsm.h for more
- * details.
- *
- * Return: 0 on success, -errno on failure
- */
-int snp_svsm_vtpm_send_command(u8 *buffer)
-{
- struct svsm_call call = {};
-
- call.caa = svsm_get_caa();
- call.rax = SVSM_VTPM_CALL(SVSM_VTPM_CMD);
- call.rcx = __pa(buffer);
-
- return svsm_perform_call_protocol(&call);
-}
-EXPORT_SYMBOL_GPL(snp_svsm_vtpm_send_command);
-
static struct platform_device sev_guest_device = {
.name = "sev-guest",
.id = -1,
enum es_result verify_exception_info(struct ghcb *ghcb, struct es_em_ctxt *ctxt);
void vc_forward_exception(struct es_em_ctxt *ctxt);
+void svsm_pval_pages(struct snp_psc_desc *desc);
+int svsm_perform_call_protocol(struct svsm_call *call);
+bool snp_svsm_vtpm_probe(void);
static inline u64 sev_es_rd_ghcb_msr(void)
{
u64 get_hv_features(void);
const struct snp_cpuid_table *snp_cpuid_get_table(void);
+
+static inline struct svsm_ca *svsm_get_caa(void)
+{
+ if (sev_cfg.use_cas)
+ return this_cpu_read(svsm_caa);
+ else
+ return rip_rel_ptr(&boot_svsm_ca_page);
+}
+
+static inline u64 svsm_get_caa_pa(void)
+{
+ if (sev_cfg.use_cas)
+ return this_cpu_read(svsm_caa_pa);
+ else
+ return boot_svsm_caa_pa;
+}
+
+static inline void __pval_terminate(u64 pfn, bool action, unsigned int page_size,
+ int ret, u64 svsm_ret)
+{
+ WARN(1, "PVALIDATE failure: pfn: 0x%llx, action: %u, size: %u, ret: %d, svsm_ret: 0x%llx\n",
+ pfn, action, page_size, ret, svsm_ret);
+
+ sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PVALIDATE);
+}
+
#endif /* __X86_COCO_SEV_INTERNAL_H__ */
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * SVSM support code
+ */
+
+#include <linux/types.h>
+
+#include <asm/sev.h>
+
+#include "internal.h"
+
+/* For early boot SVSM communication */
+struct svsm_ca boot_svsm_ca_page __aligned(PAGE_SIZE);
+SYM_PIC_ALIAS(boot_svsm_ca_page);
+
+/*
+ * SVSM related information:
+ * During boot, the page tables are set up as identity mapped and later
+ * changed to use kernel virtual addresses. Maintain separate virtual and
+ * physical addresses for the CAA to allow SVSM functions to be used during
+ * early boot, both with identity mapped virtual addresses and proper kernel
+ * virtual addresses.
+ */
+u64 boot_svsm_caa_pa __ro_after_init;
+SYM_PIC_ALIAS(boot_svsm_caa_pa);
+
+DEFINE_PER_CPU(struct svsm_ca *, svsm_caa);
+DEFINE_PER_CPU(u64, svsm_caa_pa);
+
+static int svsm_perform_ghcb_protocol(struct ghcb *ghcb, struct svsm_call *call)
+{
+ struct es_em_ctxt ctxt;
+ u8 pending = 0;
+
+ vc_ghcb_invalidate(ghcb);
+
+ /*
+ * Fill in protocol and format specifiers. This can be called very early
+ * in the boot, so use rip-relative references as needed.
+ */
+ ghcb->protocol_version = ghcb_version;
+ ghcb->ghcb_usage = GHCB_DEFAULT_USAGE;
+
+ ghcb_set_sw_exit_code(ghcb, SVM_VMGEXIT_SNP_RUN_VMPL);
+ ghcb_set_sw_exit_info_1(ghcb, 0);
+ ghcb_set_sw_exit_info_2(ghcb, 0);
+
+ sev_es_wr_ghcb_msr(__pa(ghcb));
+
+ svsm_issue_call(call, &pending);
+
+ if (pending)
+ return -EINVAL;
+
+ switch (verify_exception_info(ghcb, &ctxt)) {
+ case ES_OK:
+ break;
+ case ES_EXCEPTION:
+ vc_forward_exception(&ctxt);
+ fallthrough;
+ default:
+ return -EINVAL;
+ }
+
+ return svsm_process_result_codes(call);
+}
+
+int svsm_perform_call_protocol(struct svsm_call *call)
+{
+ struct ghcb_state state;
+ unsigned long flags;
+ struct ghcb *ghcb;
+ int ret;
+
+ flags = native_local_irq_save();
+
+ if (sev_cfg.ghcbs_initialized)
+ ghcb = __sev_get_ghcb(&state);
+ else if (boot_ghcb)
+ ghcb = boot_ghcb;
+ else
+ ghcb = NULL;
+
+ do {
+ ret = ghcb ? svsm_perform_ghcb_protocol(ghcb, call)
+ : __pi_svsm_perform_msr_protocol(call);
+ } while (ret == -EAGAIN);
+
+ if (sev_cfg.ghcbs_initialized)
+ __sev_put_ghcb(&state);
+
+ native_local_irq_restore(flags);
+
+ return ret;
+}
+
+static u64 svsm_build_ca_from_pfn_range(u64 pfn, u64 pfn_end, bool action,
+ struct svsm_pvalidate_call *pc)
+{
+ struct svsm_pvalidate_entry *pe;
+
+ /* Nothing in the CA yet */
+ pc->num_entries = 0;
+ pc->cur_index = 0;
+
+ pe = &pc->entry[0];
+
+ while (pfn < pfn_end) {
+ pe->page_size = RMP_PG_SIZE_4K;
+ pe->action = action;
+ pe->ignore_cf = 0;
+ pe->rsvd = 0;
+ pe->pfn = pfn;
+
+ pe++;
+ pfn++;
+
+ pc->num_entries++;
+ if (pc->num_entries == SVSM_PVALIDATE_MAX_COUNT)
+ break;
+ }
+
+ return pfn;
+}
+
+static int svsm_build_ca_from_psc_desc(struct snp_psc_desc *desc, unsigned int desc_entry,
+ struct svsm_pvalidate_call *pc)
+{
+ struct svsm_pvalidate_entry *pe;
+ struct psc_entry *e;
+
+ /* Nothing in the CA yet */
+ pc->num_entries = 0;
+ pc->cur_index = 0;
+
+ pe = &pc->entry[0];
+ e = &desc->entries[desc_entry];
+
+ while (desc_entry <= desc->hdr.end_entry) {
+ pe->page_size = e->pagesize ? RMP_PG_SIZE_2M : RMP_PG_SIZE_4K;
+ pe->action = e->operation == SNP_PAGE_STATE_PRIVATE;
+ pe->ignore_cf = 0;
+ pe->rsvd = 0;
+ pe->pfn = e->gfn;
+
+ pe++;
+ e++;
+
+ desc_entry++;
+ pc->num_entries++;
+ if (pc->num_entries == SVSM_PVALIDATE_MAX_COUNT)
+ break;
+ }
+
+ return desc_entry;
+}
+
+static void svsm_pval_terminate(struct svsm_pvalidate_call *pc, int ret, u64 svsm_ret)
+{
+ unsigned int page_size;
+ bool action;
+ u64 pfn;
+
+ pfn = pc->entry[pc->cur_index].pfn;
+ action = pc->entry[pc->cur_index].action;
+ page_size = pc->entry[pc->cur_index].page_size;
+
+ __pval_terminate(pfn, action, page_size, ret, svsm_ret);
+}
+
+void svsm_pval_pages(struct snp_psc_desc *desc)
+{
+ struct svsm_pvalidate_entry pv_4k[VMGEXIT_PSC_MAX_ENTRY];
+ unsigned int i, pv_4k_count = 0;
+ struct svsm_pvalidate_call *pc;
+ struct svsm_call call = {};
+ unsigned long flags;
+ bool action;
+ u64 pc_pa;
+ int ret;
+
+ /*
+ * This can be called very early in the boot, use native functions in
+ * order to avoid paravirt issues.
+ */
+ flags = native_local_irq_save();
+
+ /*
+ * The SVSM calling area (CA) can support processing 510 entries at a
+ * time. Loop through the Page State Change descriptor until the CA is
+ * full or the last entry in the descriptor is reached, at which time
+ * the SVSM is invoked. This repeats until all entries in the descriptor
+ * are processed.
+ */
+ call.caa = svsm_get_caa();
+
+ pc = (struct svsm_pvalidate_call *)call.caa->svsm_buffer;
+ pc_pa = svsm_get_caa_pa() + offsetof(struct svsm_ca, svsm_buffer);
+
+ /* Protocol 0, Call ID 1 */
+ call.rax = SVSM_CORE_CALL(SVSM_CORE_PVALIDATE);
+ call.rcx = pc_pa;
+
+ for (i = 0; i <= desc->hdr.end_entry;) {
+ i = svsm_build_ca_from_psc_desc(desc, i, pc);
+
+ do {
+ ret = svsm_perform_call_protocol(&call);
+ if (!ret)
+ continue;
+
+ /*
+ * Check if the entry failed because of an RMP mismatch (a
+ * PVALIDATE at 2M was requested, but the page is mapped in
+ * the RMP as 4K).
+ */
+
+ if (call.rax_out == SVSM_PVALIDATE_FAIL_SIZEMISMATCH &&
+ pc->entry[pc->cur_index].page_size == RMP_PG_SIZE_2M) {
+ /* Save this entry for post-processing at 4K */
+ pv_4k[pv_4k_count++] = pc->entry[pc->cur_index];
+
+ /* Skip to the next one unless at the end of the list */
+ pc->cur_index++;
+ if (pc->cur_index < pc->num_entries)
+ ret = -EAGAIN;
+ else
+ ret = 0;
+ }
+ } while (ret == -EAGAIN);
+
+ if (ret)
+ svsm_pval_terminate(pc, ret, call.rax_out);
+ }
+
+ /* Process any entries that failed to be validated at 2M and validate them at 4K */
+ for (i = 0; i < pv_4k_count; i++) {
+ u64 pfn, pfn_end;
+
+ action = pv_4k[i].action;
+ pfn = pv_4k[i].pfn;
+ pfn_end = pfn + 512;
+
+ while (pfn < pfn_end) {
+ pfn = svsm_build_ca_from_pfn_range(pfn, pfn_end, action, pc);
+
+ ret = svsm_perform_call_protocol(&call);
+ if (ret)
+ svsm_pval_terminate(pc, ret, call.rax_out);
+ }
+ }
+
+ native_local_irq_restore(flags);
+}
+
+static void update_attest_input(struct svsm_call *call, struct svsm_attest_call *input)
+{
+ /* If (new) lengths have been returned, propagate them up */
+ if (call->rcx_out != call->rcx)
+ input->manifest_buf.len = call->rcx_out;
+
+ if (call->rdx_out != call->rdx)
+ input->certificates_buf.len = call->rdx_out;
+
+ if (call->r8_out != call->r8)
+ input->report_buf.len = call->r8_out;
+}
+
+int snp_issue_svsm_attest_req(u64 call_id, struct svsm_call *call,
+ struct svsm_attest_call *input)
+{
+ struct svsm_attest_call *ac;
+ unsigned long flags;
+ u64 attest_call_pa;
+ int ret;
+
+ if (!snp_vmpl)
+ return -EINVAL;
+
+ local_irq_save(flags);
+
+ call->caa = svsm_get_caa();
+
+ ac = (struct svsm_attest_call *)call->caa->svsm_buffer;
+ attest_call_pa = svsm_get_caa_pa() + offsetof(struct svsm_ca, svsm_buffer);
+
+ *ac = *input;
+
+ /*
+ * Set input registers for the request and set RDX and R8 to known
+ * values in order to detect length values being returned in them.
+ */
+ call->rax = call_id;
+ call->rcx = attest_call_pa;
+ call->rdx = -1;
+ call->r8 = -1;
+ ret = svsm_perform_call_protocol(call);
+ update_attest_input(call, input);
+
+ local_irq_restore(flags);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(snp_issue_svsm_attest_req);
+
+/**
+ * snp_svsm_vtpm_send_command() - Execute a vTPM operation on SVSM
+ * @buffer: A buffer used to both send the command and receive the response.
+ *
+ * Execute a SVSM_VTPM_CMD call as defined by
+ * "Secure VM Service Module for SEV-SNP Guests" Publication # 58019 Revision: 1.00
+ *
+ * All command request/response buffers have a common structure as specified by
+ * the following table:
+ * Byte Size In/Out Description
+ * Offset (Bytes)
+ * 0x000 4 In Platform command
+ * Out Platform command response size
+ *
+ * Each command can build upon this common request/response structure to create
+ * a structure specific to the command. See include/linux/tpm_svsm.h for more
+ * details.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+int snp_svsm_vtpm_send_command(u8 *buffer)
+{
+ struct svsm_call call = {};
+
+ call.caa = svsm_get_caa();
+ call.rax = SVSM_VTPM_CALL(SVSM_VTPM_CMD);
+ call.rcx = __pa(buffer);
+
+ return svsm_perform_call_protocol(&call);
+}
+EXPORT_SYMBOL_GPL(snp_svsm_vtpm_send_command);
+
+/**
+ * snp_svsm_vtpm_probe() - Probe if SVSM provides a vTPM device
+ *
+ * Check that there is SVSM and that it supports at least TPM_SEND_COMMAND
+ * which is the only request used so far.
+ *
+ * Return: true if the platform provides a vTPM SVSM device, false otherwise.
+ */
+bool snp_svsm_vtpm_probe(void)
+{
+ struct svsm_call call = {};
+
+ /* The vTPM device is available only if a SVSM is present */
+ if (!snp_vmpl)
+ return false;
+
+ call.caa = svsm_get_caa();
+ call.rax = SVSM_VTPM_CALL(SVSM_VTPM_QUERY);
+
+ if (svsm_perform_call_protocol(&call))
+ return false;
+
+ /* Check platform commands contains TPM_SEND_COMMAND - platform command 8 */
+ return call.rcx_out & BIT_ULL(8);
+}
projects / thirdparty / kernel / linux.git / commitdiff
