1 // SPDX-License-Identifier: GPL-2.0-only
2
3 #include "error.h"
4 #include "misc.h"
5 #include "tdx.h"
6 #include "sev.h"
7 #include <asm/shared/tdx.h>
8
9 /*
10 * accept_memory() and process_unaccepted_memory() called from EFI stub which
11 * runs before decompressor and its early_tdx_detect().
12 *
13 * Enumerate TDX directly from the early users.
14 */
early_is_tdx_guest(void)15 static bool early_is_tdx_guest(void)
16 {
17 static bool once;
18 static bool is_tdx;
19
20 if (!IS_ENABLED(CONFIG_INTEL_TDX_GUEST))
21 return false;
22
23 if (!once) {
24 u32 eax, sig[3];
25
26 cpuid_count(TDX_CPUID_LEAF_ID, 0, &eax,
27 &sig[0], &sig[2], &sig[1]);
28 is_tdx = !memcmp(TDX_IDENT, sig, sizeof(sig));
29 once = true;
30 }
31
32 return is_tdx;
33 }
34
arch_accept_memory(phys_addr_t start,phys_addr_t end)35 void arch_accept_memory(phys_addr_t start, phys_addr_t end)
36 {
37 static bool sevsnp;
38
39 /* Platform-specific memory-acceptance call goes here */
40 if (early_is_tdx_guest()) {
41 if (!tdx_accept_memory(start, end))
42 panic("TDX: Failed to accept memory\n");
43 } else if (sevsnp || (sev_get_status() & MSR_AMD64_SEV_SNP_ENABLED)) {
44 sevsnp = true;
45 snp_accept_memory(start, end);
46 } else {
47 error("Cannot accept memory: unknown platform\n");
48 }
49 }
50
init_unaccepted_memory(void)51 bool init_unaccepted_memory(void)
52 {
53 guid_t guid = LINUX_EFI_UNACCEPTED_MEM_TABLE_GUID;
54 struct efi_unaccepted_memory *table;
55 unsigned long cfg_table_pa;
56 unsigned int cfg_table_len;
57 enum efi_type et;
58 int ret;
59
60 et = efi_get_type(boot_params_ptr);
61 if (et == EFI_TYPE_NONE)
62 return false;
63
64 ret = efi_get_conf_table(boot_params_ptr, &cfg_table_pa, &cfg_table_len);
65 if (ret) {
66 warn("EFI config table not found.");
67 return false;
68 }
69
70 table = (void *)efi_find_vendor_table(boot_params_ptr, cfg_table_pa,
71 cfg_table_len, guid);
72 if (!table)
73 return false;
74
75 if (table->version != 1)
76 error("Unknown version of unaccepted memory table\n");
77
78 /*
79 * In many cases unaccepted_table is already set by EFI stub, but it
80 * has to be initialized again to cover cases when the table is not
81 * allocated by EFI stub or EFI stub copied the kernel image with
82 * efi_relocate_kernel() before the variable is set.
83 *
84 * It must be initialized before the first usage of accept_memory().
85 */
86 unaccepted_table = table;
87
88 return true;
89 }
90