Commit 564ea84c authored by Kiryl Shutsemau's avatar Kiryl Shutsemau Committed by Dave Hansen
Browse files

x86/tdx: Dump attributes and TD_CTLS on boot 



Dump TD configuration on boot. Attributes and TD_CTLS define TD
behavior. This information is useful for tracking down bugs.

The output ends up looking like this in practice:

[    0.000000] tdx: Guest detected
[    0.000000] tdx: Attributes: SEPT_VE_DISABLE
[    0.000000] tdx: TD_CTLS: PENDING_VE_DISABLE ENUM_TOPOLOGY VIRT_CPUID2 REDUCE_VE

Signed-off-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: default avatarDave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: default avatarNikolay Borisov <nik.borisov@suse.com>
Link: https://lore.kernel.org/all/20241202072458.447455-1-kirill.shutemov%40linux.intel.com
parent cd9ce821

arch/x86/coco/tdx/Makefile

+1 −1
Original line number Diff line number Diff line 
# SPDX-License-Identifier: GPL-2.0



obj-y += tdx.o tdx-shared.o tdcall.o
 
obj-y += debug.o tdcall.o tdx.o tdx-shared.o

arch/x86/coco/tdx/debug.c

0 → 100644
+69 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0



#undef pr_fmt

#define pr_fmt(fmt)     "tdx: " fmt



#include <linux/array_size.h>

#include <linux/printk.h>

#include <asm/tdx.h>



#define DEF_TDX_ATTR_NAME(_name) [TDX_ATTR_##_name##_BIT] = __stringify(_name)



static __initdata const char *tdx_attributes[] = {

	DEF_TDX_ATTR_NAME(DEBUG),

	DEF_TDX_ATTR_NAME(HGS_PLUS_PROF),

	DEF_TDX_ATTR_NAME(PERF_PROF),

	DEF_TDX_ATTR_NAME(PMT_PROF),

	DEF_TDX_ATTR_NAME(ICSSD),

	DEF_TDX_ATTR_NAME(LASS),

	DEF_TDX_ATTR_NAME(SEPT_VE_DISABLE),

	DEF_TDX_ATTR_NAME(MIGRTABLE),

	DEF_TDX_ATTR_NAME(PKS),

	DEF_TDX_ATTR_NAME(KL),

	DEF_TDX_ATTR_NAME(TPA),

	DEF_TDX_ATTR_NAME(PERFMON),

};



#define DEF_TD_CTLS_NAME(_name) [TD_CTLS_##_name##_BIT] = __stringify(_name)



static __initdata const char *tdcs_td_ctls[] = {

	DEF_TD_CTLS_NAME(PENDING_VE_DISABLE),

	DEF_TD_CTLS_NAME(ENUM_TOPOLOGY),

	DEF_TD_CTLS_NAME(VIRT_CPUID2),

	DEF_TD_CTLS_NAME(REDUCE_VE),

	DEF_TD_CTLS_NAME(LOCK),

};



void __init tdx_dump_attributes(u64 td_attr)

{

	pr_info("Attributes:");



	for (int i = 0; i < ARRAY_SIZE(tdx_attributes); i++) {

		if (!tdx_attributes[i])

			continue;

		if (td_attr & BIT(i))

			pr_cont(" %s", tdx_attributes[i]);

		td_attr &= ~BIT(i);

	}



	if (td_attr)

		pr_cont(" unknown:%#llx", td_attr);

	pr_cont("\n");



}



void __init tdx_dump_td_ctls(u64 td_ctls)

{

	pr_info("TD_CTLS:");



	for (int i = 0; i < ARRAY_SIZE(tdcs_td_ctls); i++) {

		if (!tdcs_td_ctls[i])

			continue;

		if (td_ctls & BIT(i))

			pr_cont(" %s", tdcs_td_ctls[i]);

		td_ctls &= ~BIT(i);

	}

	if (td_ctls)

		pr_cont(" unknown:%#llx", td_ctls);

	pr_cont("\n");

}

arch/x86/coco/tdx/tdx.c

+19 −8
Original line number Diff line number Diff line
@@ -32,9 +32,6 @@ 
#define VE_GET_PORT_NUM(e)	((e) >> 16)

#define VE_IS_IO_STRING(e)	((e) & BIT(4))



#define ATTR_DEBUG		BIT(0)

#define ATTR_SEPT_VE_DISABLE	BIT(28)



/* TDX Module call error codes */

#define TDCALL_RETURN_CODE(a)	((a) >> 32)

#define TDCALL_INVALID_OPERAND	0xc0000100
@@ -200,14 +197,14 @@ static void __noreturn tdx_panic(const char *msg) 
 *

 * TDX 1.0 does not allow the guest to disable SEPT #VE on its own. The VMM

 * controls if the guest will receive such #VE with TD attribute

 * ATTR_SEPT_VE_DISABLE.

 * TDX_ATTR_SEPT_VE_DISABLE.

 *

 * Newer TDX modules allow the guest to control if it wants to receive SEPT

 * violation #VEs.

 *

 * Check if the feature is available and disable SEPT #VE if possible.

 *

 * If the TD is allowed to disable/enable SEPT #VEs, the ATTR_SEPT_VE_DISABLE

 * If the TD is allowed to disable/enable SEPT #VEs, the TDX_ATTR_SEPT_VE_DISABLE

 * attribute is no longer reliable. It reflects the initial state of the

 * control for the TD, but it will not be updated if someone (e.g. bootloader)

 * changes it before the kernel starts. Kernel must check TDCS_TD_CTLS bit to
@@ -216,14 +213,14 @@ static void __noreturn tdx_panic(const char *msg) 
static void disable_sept_ve(u64 td_attr)

{

	const char *msg = "TD misconfiguration: SEPT #VE has to be disabled";

	bool debug = td_attr & ATTR_DEBUG;

	bool debug = td_attr & TDX_ATTR_DEBUG;

	u64 config, controls;



	/* Is this TD allowed to disable SEPT #VE */

	tdg_vm_rd(TDCS_CONFIG_FLAGS, &config);

	if (!(config & TDCS_CONFIG_FLEXIBLE_PENDING_VE)) {

		/* No SEPT #VE controls for the guest: check the attribute */

		if (td_attr & ATTR_SEPT_VE_DISABLE)

		if (td_attr & TDX_ATTR_SEPT_VE_DISABLE)

			return;



		/* Relax SEPT_VE_DISABLE check for debug TD for backtraces */
@@ -1040,6 +1037,20 @@ static void tdx_kexec_finish(void) 
	}

}



static __init void tdx_announce(void)

{

	struct tdx_module_args args = {};

	u64 controls;



	pr_info("Guest detected\n");



	tdcall(TDG_VP_INFO, &args);

	tdx_dump_attributes(args.rdx);



	tdg_vm_rd(TDCS_TD_CTLS, &controls);

	tdx_dump_td_ctls(controls);

}



void __init tdx_early_init(void)

{

	u64 cc_mask;
@@ -1109,5 +1120,5 @@ void __init tdx_early_init(void) 
	 */

	x86_cpuinit.parallel_bringup = false;



	pr_info("Guest detected\n");

	tdx_announce();

}

arch/x86/include/asm/shared/tdx.h

+36 −3
Original line number Diff line number Diff line
@@ -19,6 +19,32 @@ 
#define TDG_VM_RD			7

#define TDG_VM_WR			8



/* TDX attributes */

#define TDX_ATTR_DEBUG_BIT		0

#define TDX_ATTR_DEBUG			BIT_ULL(TDX_ATTR_DEBUG_BIT)

#define TDX_ATTR_HGS_PLUS_PROF_BIT	4

#define TDX_ATTR_HGS_PLUS_PROF		BIT_ULL(TDX_ATTR_HGS_PLUS_PROF_BIT)

#define TDX_ATTR_PERF_PROF_BIT		5

#define TDX_ATTR_PERF_PROF		BIT_ULL(TDX_ATTR_PERF_PROF_BIT)

#define TDX_ATTR_PMT_PROF_BIT		6

#define TDX_ATTR_PMT_PROF		BIT_ULL(TDX_ATTR_PMT_PROF_BIT)

#define TDX_ATTR_ICSSD_BIT		16

#define TDX_ATTR_ICSSD			BIT_ULL(TDX_ATTR_ICSSD_BIT)

#define TDX_ATTR_LASS_BIT		27

#define TDX_ATTR_LASS			BIT_ULL(TDX_ATTR_LASS_BIT)

#define TDX_ATTR_SEPT_VE_DISABLE_BIT	28

#define TDX_ATTR_SEPT_VE_DISABLE	BIT_ULL(TDX_ATTR_SEPT_VE_DISABLE_BIT)

#define TDX_ATTR_MIGRTABLE_BIT		29

#define TDX_ATTR_MIGRTABLE		BIT_ULL(TDX_ATTR_MIGRTABLE_BIT)

#define TDX_ATTR_PKS_BIT		30

#define TDX_ATTR_PKS			BIT_ULL(TDX_ATTR_PKS_BIT)

#define TDX_ATTR_KL_BIT			31

#define TDX_ATTR_KL			BIT_ULL(TDX_ATTR_KL_BIT)

#define TDX_ATTR_TPA_BIT		62

#define TDX_ATTR_TPA			BIT_ULL(TDX_ATTR_TPA_BIT)

#define TDX_ATTR_PERFMON_BIT		63

#define TDX_ATTR_PERFMON		BIT_ULL(TDX_ATTR_PERFMON_BIT)



/* TDX TD-Scope Metadata. To be used by TDG.VM.WR and TDG.VM.RD */

#define TDCS_CONFIG_FLAGS		0x1110000300000016

#define TDCS_TD_CTLS			0x1110000300000017
@@ -29,9 +55,16 @@ 
#define TDCS_CONFIG_FLEXIBLE_PENDING_VE	BIT_ULL(1)



/* TDCS_TD_CTLS bits */

#define TD_CTLS_PENDING_VE_DISABLE	BIT_ULL(0)

#define TD_CTLS_ENUM_TOPOLOGY		BIT_ULL(1)

#define TD_CTLS_REDUCE_VE		BIT_ULL(3)

#define TD_CTLS_PENDING_VE_DISABLE_BIT	0

#define TD_CTLS_PENDING_VE_DISABLE	BIT_ULL(TD_CTLS_PENDING_VE_DISABLE_BIT)

#define TD_CTLS_ENUM_TOPOLOGY_BIT	1

#define TD_CTLS_ENUM_TOPOLOGY		BIT_ULL(TD_CTLS_ENUM_TOPOLOGY_BIT)

#define TD_CTLS_VIRT_CPUID2_BIT		2

#define TD_CTLS_VIRT_CPUID2		BIT_ULL(TD_CTLS_VIRT_CPUID2_BIT)

#define TD_CTLS_REDUCE_VE_BIT		3

#define TD_CTLS_REDUCE_VE		BIT_ULL(TD_CTLS_REDUCE_VE_BIT)

#define TD_CTLS_LOCK_BIT		63

#define TD_CTLS_LOCK			BIT_ULL(TD_CTLS_LOCK_BIT)



/* TDX hypercall Leaf IDs */

#define TDVMCALL_MAP_GPA		0x10001

arch/x86/include/asm/tdx.h

+3 −0
Original line number Diff line number Diff line
@@ -66,6 +66,9 @@ int tdx_mcall_get_report0(u8 *reportdata, u8 *tdreport); 


u64 tdx_hcall_get_quote(u8 *buf, size_t size);



void __init tdx_dump_attributes(u64 td_attr);

void __init tdx_dump_td_ctls(u64 td_ctls);



#else



static inline void tdx_early_init(void) { };