[mirror_edk2.git] / OvmfPkg / SmmControl2Dxe / SmiFeatures.c

/**@file\r
  Negotiate SMI features with QEMU, and configure UefiCpuPkg/PiSmmCpuDxeSmm\r
  accordingly.\r
\r
  Copyright (C) 2016-2017, Red Hat, Inc.\r
\r
  SPDX-License-Identifier: BSD-2-Clause-Patent\r
**/\r
\r
#include <Library/BaseLib.h>\r
#include <Library/DebugLib.h>\r
#include <Library/MemEncryptSevLib.h>\r
#include <Library/MemoryAllocationLib.h>\r
#include <Library/PcdLib.h>\r
#include <Library/QemuFwCfgLib.h>\r
#include <Library/QemuFwCfgS3Lib.h>\r
\r
#include "SmiFeatures.h"\r
\r
//\r
// The following bit value stands for "broadcast SMI" in the\r
// "etc/smi/supported-features" and "etc/smi/requested-features" fw_cfg files.\r
//\r
#define ICH9_LPC_SMI_F_BROADCAST BIT0\r
//\r
// The following bit value stands for "enable CPU hotplug, and inject an SMI\r
// with control value ICH9_APM_CNT_CPU_HOTPLUG upon hotplug", in the\r
// "etc/smi/supported-features" and "etc/smi/requested-features" fw_cfg files.\r
//\r
#define ICH9_LPC_SMI_F_CPU_HOTPLUG BIT1\r
\r
//\r
// Provides a scratch buffer (allocated in EfiReservedMemoryType type memory)\r
// for the S3 boot script fragment to write to and read from.\r
//\r
#pragma pack (1)\r
typedef union {\r
  UINT64 Features;\r
  UINT8  FeaturesOk;\r
} SCRATCH_BUFFER;\r
#pragma pack ()\r
\r
//\r
// These carry the selector keys of the "etc/smi/requested-features" and\r
// "etc/smi/features-ok" fw_cfg files from NegotiateSmiFeatures() to\r
// AppendFwCfgBootScript().\r
//\r
STATIC FIRMWARE_CONFIG_ITEM mRequestedFeaturesItem;\r
STATIC FIRMWARE_CONFIG_ITEM mFeaturesOkItem;\r
\r
//\r
// Carries the negotiated SMI features from NegotiateSmiFeatures() to\r
// AppendFwCfgBootScript().\r
//\r
STATIC UINT64 mSmiFeatures;\r
\r
/**\r
  Negotiate SMI features with QEMU.\r
\r
  @retval FALSE  If SMI feature negotiation is not supported by QEMU. This is\r
                 not an error, it just means that SaveSmiFeatures() should not\r
                 be called.\r
\r
  @retval TRUE   SMI feature negotiation is supported, and it has completed\r
                 successfully as well. (Failure to negotiate is a fatal error\r
                 and the function never returns in that case.)\r
**/\r
BOOLEAN\r
NegotiateSmiFeatures (\r
  VOID\r
  )\r
{\r
  FIRMWARE_CONFIG_ITEM SupportedFeaturesItem;\r
  UINTN                SupportedFeaturesSize;\r
  UINTN                RequestedFeaturesSize;\r
  UINTN                FeaturesOkSize;\r
  UINT64               RequestedFeaturesMask;\r
\r
  //\r
  // Look up the fw_cfg files used for feature negotiation. The selector keys\r
  // of "etc/smi/requested-features" and "etc/smi/features-ok" are saved\r
  // statically. If the files are missing, then QEMU doesn't support SMI\r
  // feature negotiation.\r
  //\r
  if (RETURN_ERROR (QemuFwCfgFindFile ("etc/smi/supported-features",\r
                      &SupportedFeaturesItem, &SupportedFeaturesSize)) ||\r
      RETURN_ERROR (QemuFwCfgFindFile ("etc/smi/requested-features",\r
                      &mRequestedFeaturesItem, &RequestedFeaturesSize)) ||\r
      RETURN_ERROR (QemuFwCfgFindFile ("etc/smi/features-ok",\r
                      &mFeaturesOkItem, &FeaturesOkSize))) {\r
    DEBUG ((DEBUG_INFO, "%a: SMI feature negotiation unavailable\n",\r
      __FUNCTION__));\r
    return FALSE;\r
  }\r
\r
  //\r
  // If the files are present but their sizes disagree with us, that's a fatal\r
  // error (we can't trust the behavior of SMIs either way).\r
  //\r
  if (SupportedFeaturesSize != sizeof mSmiFeatures ||\r
      RequestedFeaturesSize != sizeof mSmiFeatures ||\r
      FeaturesOkSize != sizeof (UINT8)) {\r
    DEBUG ((DEBUG_ERROR, "%a: size mismatch in feature negotiation\n",\r
      __FUNCTION__));\r
    goto FatalError;\r
  }\r
\r
  //\r
  // Get the features supported by the host.\r
  //\r
  QemuFwCfgSelectItem (SupportedFeaturesItem);\r
  QemuFwCfgReadBytes (sizeof mSmiFeatures, &mSmiFeatures);\r
\r
  //\r
  // We want broadcast SMI, SMI on CPU hotplug, and nothing else.\r
  //\r
  RequestedFeaturesMask = ICH9_LPC_SMI_F_BROADCAST;\r
  if (!MemEncryptSevIsEnabled ()) {\r
    //\r
    // For now, we only support hotplug with SEV disabled.\r
    //\r
    RequestedFeaturesMask |= ICH9_LPC_SMI_F_CPU_HOTPLUG;\r
  }\r
  mSmiFeatures &= RequestedFeaturesMask;\r
  QemuFwCfgSelectItem (mRequestedFeaturesItem);\r
  QemuFwCfgWriteBytes (sizeof mSmiFeatures, &mSmiFeatures);\r
\r
  //\r
  // Invoke feature validation in QEMU. If the selection is accepted, the\r
  // features will be locked down. If the selection is rejected, feature\r
  // negotiation remains open; however we don't know what to do in that case,\r
  // so that's a fatal error.\r
  //\r
  QemuFwCfgSelectItem (mFeaturesOkItem);\r
  if (QemuFwCfgRead8 () != 1) {\r
    DEBUG ((DEBUG_ERROR, "%a: negotiation failed for feature bitmap 0x%Lx\n",\r
      __FUNCTION__, mSmiFeatures));\r
    goto FatalError;\r
  }\r
\r
  if ((mSmiFeatures & ICH9_LPC_SMI_F_BROADCAST) == 0) {\r
    //\r
    // If we can't get broadcast SMIs from QEMU, that's acceptable too,\r
    // although not optimal.\r
    //\r
    DEBUG ((DEBUG_INFO, "%a: SMI broadcast unavailable\n", __FUNCTION__));\r
  } else {\r
    //\r
    // Configure the traditional AP sync / SMI delivery mode for\r
    // PiSmmCpuDxeSmm. Effectively, restore the UefiCpuPkg defaults, from which\r
    // the original QEMU behavior (i.e., unicast SMI) used to differ.\r
    //\r
    if (RETURN_ERROR (PcdSet64S (PcdCpuSmmApSyncTimeout, 1000000)) ||\r
        RETURN_ERROR (PcdSet8S (PcdCpuSmmSyncMode, 0x00))) {\r
      DEBUG ((DEBUG_ERROR, "%a: PiSmmCpuDxeSmm PCD configuration failed\n",\r
        __FUNCTION__));\r
      goto FatalError;\r
    }\r
    DEBUG ((DEBUG_INFO, "%a: using SMI broadcast\n", __FUNCTION__));\r
  }\r
\r
  if ((mSmiFeatures & ICH9_LPC_SMI_F_CPU_HOTPLUG) == 0) {\r
    DEBUG ((DEBUG_INFO, "%a: CPU hotplug not negotiated\n", __FUNCTION__));\r
  } else {\r
    DEBUG ((DEBUG_INFO, "%a: CPU hotplug with SMI negotiated\n",\r
      __FUNCTION__));\r
  }\r
\r
  //\r
  // Negotiation successful (although we may not have gotten the optimal\r
  // feature set).\r
  //\r
  return TRUE;\r
\r
FatalError:\r
  ASSERT (FALSE);\r
  CpuDeadLoop ();\r
  //\r
  // Keep the compiler happy.\r
  //\r
  return FALSE;\r
}\r
\r
/**\r
  FW_CFG_BOOT_SCRIPT_CALLBACK_FUNCTION provided to QemuFwCfgS3Lib.\r
**/\r
STATIC\r
VOID\r
EFIAPI\r
AppendFwCfgBootScript (\r
  IN OUT VOID *Context,              OPTIONAL\r
  IN OUT VOID *ExternalScratchBuffer\r
  )\r
{\r
  SCRATCH_BUFFER *ScratchBuffer;\r
  RETURN_STATUS  Status;\r
\r
  ScratchBuffer = ExternalScratchBuffer;\r
\r
  //\r
  // Write the negotiated feature bitmap into "etc/smi/requested-features".\r
  //\r
  ScratchBuffer->Features = mSmiFeatures;\r
  Status = QemuFwCfgS3ScriptWriteBytes (mRequestedFeaturesItem,\r
             sizeof ScratchBuffer->Features);\r
  if (RETURN_ERROR (Status)) {\r
    goto FatalError;\r
  }\r
\r
  //\r
  // Read back "etc/smi/features-ok". This invokes the feature validation &\r
  // lockdown. (The validation succeeded at first boot.)\r
  //\r
  Status = QemuFwCfgS3ScriptReadBytes (mFeaturesOkItem,\r
             sizeof ScratchBuffer->FeaturesOk);\r
  if (RETURN_ERROR (Status)) {\r
    goto FatalError;\r
  }\r
\r
  //\r
  // If "etc/smi/features-ok" read as 1, we're good. Otherwise, hang the S3\r
  // resume process.\r
  //\r
  Status = QemuFwCfgS3ScriptCheckValue (&ScratchBuffer->FeaturesOk,\r
             sizeof ScratchBuffer->FeaturesOk, MAX_UINT8, 1);\r
  if (RETURN_ERROR (Status)) {\r
    goto FatalError;\r
  }\r
\r
  DEBUG ((DEBUG_VERBOSE, "%a: SMI feature negotiation boot script saved\n",\r
    __FUNCTION__));\r
  return;\r
\r
FatalError:\r
  ASSERT (FALSE);\r
  CpuDeadLoop ();\r
}\r
\r
\r
/**\r
  Append a boot script fragment that will re-select the previously negotiated\r
  SMI features during S3 resume.\r
**/\r
VOID\r
SaveSmiFeatures (\r
  VOID\r
  )\r
{\r
  RETURN_STATUS Status;\r
\r
  //\r
  // We are already running at TPL_CALLBACK, on the stack of\r
  // OnS3SaveStateInstalled(). But that's okay, we can easily queue more\r
  // notification functions while executing a notification function.\r
  //\r
  Status = QemuFwCfgS3CallWhenBootScriptReady (AppendFwCfgBootScript, NULL,\r
             sizeof (SCRATCH_BUFFER));\r
  if (RETURN_ERROR (Status)) {\r
    ASSERT (FALSE);\r
    CpuDeadLoop ();\r
  }\r
}\r
Commit	Line	Data
a316d7ac LE	1	/**@file\r
	2	Negotiate SMI features with QEMU, and configure UefiCpuPkg/PiSmmCpuDxeSmm\r
	3	accordingly.\r
	4	\r
	5	Copyright (C) 2016-2017, Red Hat, Inc.\r
	6	\r
b26f0cf9	7	SPDX-License-Identifier: BSD-2-Clause-Patent\r
a316d7ac LE	8	**/\r
	9	\r
	10	#include <Library/BaseLib.h>\r
	11	#include <Library/DebugLib.h>\r
5ba203b5	12	#include <Library/MemEncryptSevLib.h>\r
a316d7ac LE	13	#include <Library/MemoryAllocationLib.h>\r
	14	#include <Library/PcdLib.h>\r
	15	#include <Library/QemuFwCfgLib.h>\r
36a6aa6c	16	#include <Library/QemuFwCfgS3Lib.h>\r
a316d7ac LE	17	\r
	18	#include "SmiFeatures.h"\r
	19	\r
	20	//\r
	21	// The following bit value stands for "broadcast SMI" in the\r
	22	// "etc/smi/supported-features" and "etc/smi/requested-features" fw_cfg files.\r
	23	//\r
	24	#define ICH9_LPC_SMI_F_BROADCAST BIT0\r
5ba203b5 LE	25	//\r
	26	// The following bit value stands for "enable CPU hotplug, and inject an SMI\r
	27	// with control value ICH9_APM_CNT_CPU_HOTPLUG upon hotplug", in the\r
	28	// "etc/smi/supported-features" and "etc/smi/requested-features" fw_cfg files.\r
	29	//\r
	30	#define ICH9_LPC_SMI_F_CPU_HOTPLUG BIT1\r
a316d7ac LE	31	\r
	32	//\r
	33	// Provides a scratch buffer (allocated in EfiReservedMemoryType type memory)\r
36a6aa6c	34	// for the S3 boot script fragment to write to and read from.\r
a316d7ac LE	35	//\r
a316d7ac LE	36	#pragma pack (1)\r
36a6aa6c LE	37	typedef union {\r
	38	UINT64 Features;\r
	39	UINT8 FeaturesOk;\r
a316d7ac LE	40	} SCRATCH_BUFFER;\r
	41	#pragma pack ()\r
	42	\r
	43	//\r
	44	// These carry the selector keys of the "etc/smi/requested-features" and\r
	45	// "etc/smi/features-ok" fw_cfg files from NegotiateSmiFeatures() to\r
36a6aa6c	46	// AppendFwCfgBootScript().\r
a316d7ac LE	47	//\r
	48	STATIC FIRMWARE_CONFIG_ITEM mRequestedFeaturesItem;\r
	49	STATIC FIRMWARE_CONFIG_ITEM mFeaturesOkItem;\r
	50	\r
	51	//\r
	52	// Carries the negotiated SMI features from NegotiateSmiFeatures() to\r
36a6aa6c	53	// AppendFwCfgBootScript().\r
a316d7ac LE	54	//\r
	55	STATIC UINT64 mSmiFeatures;\r
	56	\r
	57	/**\r
	58	Negotiate SMI features with QEMU.\r
	59	\r
	60	@retval FALSE If SMI feature negotiation is not supported by QEMU. This is\r
	61	not an error, it just means that SaveSmiFeatures() should not\r
	62	be called.\r
	63	\r
	64	@retval TRUE SMI feature negotiation is supported, and it has completed\r
	65	successfully as well. (Failure to negotiate is a fatal error\r
	66	and the function never returns in that case.)\r
	67	**/\r
	68	BOOLEAN\r
	69	NegotiateSmiFeatures (\r
	70	VOID\r
	71	)\r
	72	{\r
	73	FIRMWARE_CONFIG_ITEM SupportedFeaturesItem;\r
	74	UINTN SupportedFeaturesSize;\r
	75	UINTN RequestedFeaturesSize;\r
	76	UINTN FeaturesOkSize;\r
5ba203b5	77	UINT64 RequestedFeaturesMask;\r
a316d7ac LE	78	\r
	79	//\r
	80	// Look up the fw_cfg files used for feature negotiation. The selector keys\r
	81	// of "etc/smi/requested-features" and "etc/smi/features-ok" are saved\r
	82	// statically. If the files are missing, then QEMU doesn't support SMI\r
	83	// feature negotiation.\r
	84	//\r
	85	if (RETURN_ERROR (QemuFwCfgFindFile ("etc/smi/supported-features",\r
	86	&SupportedFeaturesItem, &SupportedFeaturesSize)) \|\|\r
	87	RETURN_ERROR (QemuFwCfgFindFile ("etc/smi/requested-features",\r
	88	&mRequestedFeaturesItem, &RequestedFeaturesSize)) \|\|\r
	89	RETURN_ERROR (QemuFwCfgFindFile ("etc/smi/features-ok",\r
	90	&mFeaturesOkItem, &FeaturesOkSize))) {\r
	91	DEBUG ((DEBUG_INFO, "%a: SMI feature negotiation unavailable\n",\r
	92	__FUNCTION__));\r
	93	return FALSE;\r
	94	}\r
	95	\r
	96	//\r
	97	// If the files are present but their sizes disagree with us, that's a fatal\r
	98	// error (we can't trust the behavior of SMIs either way).\r
	99	//\r
	100	if (SupportedFeaturesSize != sizeof mSmiFeatures \|\|\r
	101	RequestedFeaturesSize != sizeof mSmiFeatures \|\|\r
	102	FeaturesOkSize != sizeof (UINT8)) {\r
	103	DEBUG ((DEBUG_ERROR, "%a: size mismatch in feature negotiation\n",\r
	104	__FUNCTION__));\r
	105	goto FatalError;\r
	106	}\r
	107	\r
	108	//\r
	109	// Get the features supported by the host.\r
	110	//\r
	111	QemuFwCfgSelectItem (SupportedFeaturesItem);\r
	112	QemuFwCfgReadBytes (sizeof mSmiFeatures, &mSmiFeatures);\r
	113	\r
	114	//\r
5ba203b5	115	// We want broadcast SMI, SMI on CPU hotplug, and nothing else.\r
a316d7ac	116	//\r
5ba203b5 LE	117	RequestedFeaturesMask = ICH9_LPC_SMI_F_BROADCAST;\r
	118	if (!MemEncryptSevIsEnabled ()) {\r
	119	//\r
	120	// For now, we only support hotplug with SEV disabled.\r
	121	//\r
	122	RequestedFeaturesMask \|= ICH9_LPC_SMI_F_CPU_HOTPLUG;\r
	123	}\r
	124	mSmiFeatures &= RequestedFeaturesMask;\r
a316d7ac LE	125	QemuFwCfgSelectItem (mRequestedFeaturesItem);\r
	126	QemuFwCfgWriteBytes (sizeof mSmiFeatures, &mSmiFeatures);\r
	127	\r
	128	//\r
	129	// Invoke feature validation in QEMU. If the selection is accepted, the\r
	130	// features will be locked down. If the selection is rejected, feature\r
	131	// negotiation remains open; however we don't know what to do in that case,\r
	132	// so that's a fatal error.\r
	133	//\r
	134	QemuFwCfgSelectItem (mFeaturesOkItem);\r
	135	if (QemuFwCfgRead8 () != 1) {\r
	136	DEBUG ((DEBUG_ERROR, "%a: negotiation failed for feature bitmap 0x%Lx\n",\r
	137	__FUNCTION__, mSmiFeatures));\r
	138	goto FatalError;\r
	139	}\r
	140	\r
	141	if ((mSmiFeatures & ICH9_LPC_SMI_F_BROADCAST) == 0) {\r
	142	//\r
	143	// If we can't get broadcast SMIs from QEMU, that's acceptable too,\r
	144	// although not optimal.\r
	145	//\r
	146	DEBUG ((DEBUG_INFO, "%a: SMI broadcast unavailable\n", __FUNCTION__));\r
	147	} else {\r
	148	//\r
	149	// Configure the traditional AP sync / SMI delivery mode for\r
	150	// PiSmmCpuDxeSmm. Effectively, restore the UefiCpuPkg defaults, from which\r
	151	// the original QEMU behavior (i.e., unicast SMI) used to differ.\r
	152	//\r
	153	if (RETURN_ERROR (PcdSet64S (PcdCpuSmmApSyncTimeout, 1000000)) \|\|\r
	154	RETURN_ERROR (PcdSet8S (PcdCpuSmmSyncMode, 0x00))) {\r
	155	DEBUG ((DEBUG_ERROR, "%a: PiSmmCpuDxeSmm PCD configuration failed\n",\r
	156	__FUNCTION__));\r
	157	goto FatalError;\r
	158	}\r
	159	DEBUG ((DEBUG_INFO, "%a: using SMI broadcast\n", __FUNCTION__));\r
	160	}\r
	161	\r
5ba203b5 LE	162	if ((mSmiFeatures & ICH9_LPC_SMI_F_CPU_HOTPLUG) == 0) {\r
	163	DEBUG ((DEBUG_INFO, "%a: CPU hotplug not negotiated\n", __FUNCTION__));\r
	164	} else {\r
	165	DEBUG ((DEBUG_INFO, "%a: CPU hotplug with SMI negotiated\n",\r
	166	__FUNCTION__));\r
	167	}\r
	168	\r
a316d7ac LE	169	//\r
	170	// Negotiation successful (although we may not have gotten the optimal\r
	171	// feature set).\r
	172	//\r
	173	return TRUE;\r
	174	\r
	175	FatalError:\r
	176	ASSERT (FALSE);\r
	177	CpuDeadLoop ();\r
	178	//\r
	179	// Keep the compiler happy.\r
	180	//\r
	181	return FALSE;\r
	182	}\r
	183	\r
	184	/**\r
36a6aa6c	185	FW_CFG_BOOT_SCRIPT_CALLBACK_FUNCTION provided to QemuFwCfgS3Lib.\r
a316d7ac	186	**/\r
36a6aa6c	187	STATIC\r
a316d7ac	188	VOID\r
36a6aa6c LE	189	EFIAPI\r
	190	AppendFwCfgBootScript (\r
	191	IN OUT VOID *Context, OPTIONAL\r
	192	IN OUT VOID *ExternalScratchBuffer\r
a316d7ac LE	193	)\r
	194	{\r
	195	SCRATCH_BUFFER *ScratchBuffer;\r
36a6aa6c	196	RETURN_STATUS Status;\r
a316d7ac	197	\r
36a6aa6c	198	ScratchBuffer = ExternalScratchBuffer;\r
a316d7ac LE	199	\r
a316d7ac LE	200	//\r
36a6aa6c	201	// Write the negotiated feature bitmap into "etc/smi/requested-features".\r
a316d7ac	202	//\r
36a6aa6c LE	203	ScratchBuffer->Features = mSmiFeatures;\r
	204	Status = QemuFwCfgS3ScriptWriteBytes (mRequestedFeaturesItem,\r
	205	sizeof ScratchBuffer->Features);\r
	206	if (RETURN_ERROR (Status)) {\r
a316d7ac LE	207	goto FatalError;\r
	208	}\r
	209	\r
	210	//\r
36a6aa6c LE	211	// Read back "etc/smi/features-ok". This invokes the feature validation &\r
36a6aa6c LE	212	// lockdown. (The validation succeeded at first boot.)\r
a316d7ac	213	//\r
36a6aa6c LE	214	Status = QemuFwCfgS3ScriptReadBytes (mFeaturesOkItem,\r
	215	sizeof ScratchBuffer->FeaturesOk);\r
	216	if (RETURN_ERROR (Status)) {\r
a316d7ac LE	217	goto FatalError;\r
	218	}\r
	219	\r
	220	//\r
36a6aa6c LE	221	// If "etc/smi/features-ok" read as 1, we're good. Otherwise, hang the S3\r
36a6aa6c LE	222	// resume process.\r
a316d7ac	223	//\r
36a6aa6c LE	224	Status = QemuFwCfgS3ScriptCheckValue (&ScratchBuffer->FeaturesOk,\r
	225	sizeof ScratchBuffer->FeaturesOk, MAX_UINT8, 1);\r
	226	if (RETURN_ERROR (Status)) {\r
a316d7ac LE	227	goto FatalError;\r
	228	}\r
	229	\r
36a6aa6c LE	230	DEBUG ((DEBUG_VERBOSE, "%a: SMI feature negotiation boot script saved\n",\r
36a6aa6c LE	231	__FUNCTION__));\r
a316d7ac LE	232	return;\r
	233	\r
	234	FatalError:\r
	235	ASSERT (FALSE);\r
	236	CpuDeadLoop ();\r
	237	}\r
36a6aa6c LE	238	\r
	239	\r
	240	/**\r
	241	Append a boot script fragment that will re-select the previously negotiated\r
	242	SMI features during S3 resume.\r
	243	**/\r
	244	VOID\r
	245	SaveSmiFeatures (\r
	246	VOID\r
	247	)\r
	248	{\r
	249	RETURN_STATUS Status;\r
	250	\r
	251	//\r
	252	// We are already running at TPL_CALLBACK, on the stack of\r
	253	// OnS3SaveStateInstalled(). But that's okay, we can easily queue more\r
	254	// notification functions while executing a notification function.\r
	255	//\r
	256	Status = QemuFwCfgS3CallWhenBootScriptReady (AppendFwCfgBootScript, NULL,\r
	257	sizeof (SCRATCH_BUFFER));\r
	258	if (RETURN_ERROR (Status)) {\r
	259	ASSERT (FALSE);\r
	260	CpuDeadLoop ();\r
	261	}\r
	262	}\r