arm-trusted-firmware/common/feat_detect.c
Andre Przywara ea735bf556 refactor(cpufeat): enable FEAT_VHE for FEAT_STATE_CHECKED
At the moment we only support FEAT_VHE to be either unconditionally
compiled in, or to be not supported at all.

Add support for runtime detection (ENABLE_FEAT_VHE=2), by splitting
is_armv8_1_vhe_present() into an ID register reading function and a
second function to report the support status. That function considers
both build time settings and runtime information (if needed), and is
used before we access VHE related registers.
Also move the context saving code from assembly to C, and use the new
is_feat_vhe_supported() function to guard its execution.

Enable VHE in its runtime detection version for all FVP builds.

Change-Id: Ib397cd0c83e8c709bd6fed603560e39901fa672b
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
2023-03-20 13:37:37 +00:00

314 lines
10 KiB
C

/*
* Copyright (c) 2022, Arm Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <arch_features.h>
#include <common/debug.h>
#include <common/feat_detect.h>
static bool tainted;
/*******************************************************************************
* This section lists the wrapper modules for each feature to evaluate the
* feature states (FEAT_STATE_ALWAYS and FEAT_STATE_CHECK) and perform
* necessary action as below:
*
* It verifies whether the FEAT_XXX (eg: FEAT_SB) is supported by the PE or not.
* Without this check an exception would occur during context save/restore
* routines, if the feature is enabled but not supported by PE.
******************************************************************************/
#define feat_detect_panic(a, b) ((a) ? (void)0 : feature_panic(b))
/*******************************************************************************
* Function : feature_panic
* Customised panic function with error logging mechanism to list the feature
* not supported by the PE.
******************************************************************************/
static inline void feature_panic(char *feat_name)
{
ERROR("FEAT_%s not supported by the PE\n", feat_name);
panic();
}
/*******************************************************************************
* Function : check_feature
* Check for a valid combination of build time flags (ENABLE_FEAT_xxx) and
* feature availability on the hardware. <min> is the smallest feature
* ID field value that is required for that feature.
* Triggers a panic later if a feature is forcefully enabled, but not
* available on the PE. Also will panic if the hardware feature ID field
* is larger than the maximum known and supported number, specified by <max>.
*
* We force inlining here to let the compiler optimise away the whole check
* if the feature is disabled at build time (FEAT_STATE_DISABLED).
******************************************************************************/
static inline void __attribute((__always_inline__))
check_feature(int state, unsigned long field, const char *feat_name,
unsigned int min, unsigned int max)
{
if (state == FEAT_STATE_ALWAYS && field < min) {
ERROR("FEAT_%s not supported by the PE\n", feat_name);
tainted = true;
}
if (state >= FEAT_STATE_ALWAYS && field > max) {
ERROR("FEAT_%s is version %ld, but is only known up to version %d\n",
feat_name, field, max);
tainted = true;
}
}
/******************************************
* Feature : FEAT_SB (Speculation Barrier)
*****************************************/
static void read_feat_sb(void)
{
#if (ENABLE_FEAT_SB == FEAT_STATE_ALWAYS)
feat_detect_panic(is_armv8_0_feat_sb_present(), "SB");
#endif
}
/******************************************************
* Feature : FEAT_CSV2_2 (Cache Speculation Variant 2)
*****************************************************/
static void read_feat_csv2_2(void)
{
#if (ENABLE_FEAT_CSV2_2 == FEAT_STATE_ALWAYS)
feat_detect_panic(is_armv8_0_feat_csv2_2_present(), "CSV2_2");
#endif
}
/***********************************************
* Feature : FEAT_PAN (Privileged Access Never)
**********************************************/
static void read_feat_pan(void)
{
#if (ENABLE_FEAT_PAN == FEAT_STATE_ALWAYS)
feat_detect_panic(is_armv8_1_pan_present(), "PAN");
#endif
}
/*******************************************************************************
* Feature : FEAT_RAS (Reliability, Availability, and Serviceability Extension)
******************************************************************************/
static void read_feat_ras(void)
{
#if (RAS_EXTENSION == FEAT_STATE_ALWAYS)
feat_detect_panic(is_armv8_2_feat_ras_present(), "RAS");
#endif
}
/************************************************
* Feature : FEAT_PAUTH (Pointer Authentication)
***********************************************/
static void read_feat_pauth(void)
{
#if (ENABLE_PAUTH == FEAT_STATE_ALWAYS) || (CTX_INCLUDE_PAUTH_REGS == FEAT_STATE_ALWAYS)
feat_detect_panic(is_armv8_3_pauth_present(), "PAUTH");
#endif
}
/************************************************************
* Feature : FEAT_DIT (Data Independent Timing Instructions)
***********************************************************/
static void read_feat_dit(void)
{
#if (ENABLE_FEAT_DIT == FEAT_STATE_ALWAYS)
feat_detect_panic(is_armv8_4_feat_dit_present(), "DIT");
#endif
}
/**************************************************************
* Feature : FEAT_NV2 (Enhanced Nested Virtualization Support)
*************************************************************/
static void read_feat_nv2(void)
{
#if (CTX_INCLUDE_NEVE_REGS == FEAT_STATE_ALWAYS)
unsigned int nv = get_armv8_4_feat_nv_support();
feat_detect_panic((nv == ID_AA64MMFR2_EL1_NV2_SUPPORTED), "NV2");
#endif
}
/***********************************
* Feature : FEAT_SEL2 (Secure EL2)
**********************************/
static void read_feat_sel2(void)
{
#if (ENABLE_FEAT_SEL2 == FEAT_STATE_ALWAYS)
feat_detect_panic(is_armv8_4_sel2_present(), "SEL2");
#endif
}
/************************************************
* Feature : FEAT_MTE (Memory Tagging Extension)
***********************************************/
static void read_feat_mte(void)
{
#if (CTX_INCLUDE_MTE_REGS == FEAT_STATE_ALWAYS)
unsigned int mte = get_armv8_5_mte_support();
feat_detect_panic((mte != MTE_UNIMPLEMENTED), "MTE");
#endif
}
/***********************************************
* Feature : FEAT_RNG (Random Number Generator)
**********************************************/
static void read_feat_rng(void)
{
#if (ENABLE_FEAT_RNG == FEAT_STATE_ALWAYS)
feat_detect_panic(is_armv8_5_rng_present(), "RNG");
#endif
}
/****************************************************
* Feature : FEAT_BTI (Branch Target Identification)
***************************************************/
static void read_feat_bti(void)
{
#if (ENABLE_BTI == FEAT_STATE_ALWAYS)
feat_detect_panic(is_armv8_5_bti_present(), "BTI");
#endif
}
/***********************************************
* Feature : FEAT_AMUv1p1 (AMU Extensions v1.1)
**********************************************/
static void read_feat_amuv1p1(void)
{
#if (ENABLE_FEAT_AMUv1p1 == FEAT_STATE_ALWAYS)
feat_detect_panic(is_armv8_6_feat_amuv1p1_present(), "AMUv1p1");
#endif
}
/*******************************************************
* Feature : FEAT_ECV (Enhanced Counter Virtualization)
******************************************************/
static void read_feat_ecv(void)
{
#if (ENABLE_FEAT_ECV == FEAT_STATE_ALWAYS)
unsigned int ecv = get_armv8_6_ecv_support();
feat_detect_panic(((ecv == ID_AA64MMFR0_EL1_ECV_SUPPORTED) ||
(ecv == ID_AA64MMFR0_EL1_ECV_SELF_SYNCH)), "ECV");
#endif
}
/***********************************************************
* Feature : FEAT_TWED (Delayed Trapping of WFE Instruction)
**********************************************************/
static void read_feat_twed(void)
{
#if (ENABLE_FEAT_TWED == FEAT_STATE_ALWAYS)
feat_detect_panic(is_armv8_6_twed_present(), "TWED");
#endif
}
/**************************************************
* Feature : FEAT_RME (Realm Management Extension)
*************************************************/
static void read_feat_rme(void)
{
#if (ENABLE_RME == FEAT_STATE_ALWAYS)
feat_detect_panic((get_armv9_2_feat_rme_support() !=
ID_AA64PFR0_FEAT_RME_NOT_SUPPORTED), "RME");
#endif
}
/******************************************************************
* Feature : FEAT_RNG_TRAP (Trapping support for RNDR/RNDRRS)
*****************************************************************/
static void read_feat_rng_trap(void)
{
#if (ENABLE_FEAT_RNG_TRAP == FEAT_STATE_ALWAYS)
feat_detect_panic(is_feat_rng_trap_present(), "RNG_TRAP");
#endif
}
/***********************************************************************************
* TF-A supports many Arm architectural features starting from arch version
* (8.0 till 8.7+). These features are mostly enabled through build flags. This
* mechanism helps in validating these build flags in the early boot phase
* either in BL1 or BL31 depending on the platform and assists in identifying
* and notifying the features which are enabled but not supported by the PE.
*
* It reads all the enabled features ID-registers and ensures the features
* are supported by the PE.
* In case if they aren't it stops booting at an early phase and logs the error
* messages, notifying the platforms about the features that are not supported.
*
* Further the procedure is implemented with a tri-state approach for each feature:
* ENABLE_FEAT_xxx = 0 : The feature is disabled statically at compile time
* ENABLE_FEAT_xxx = 1 : The feature is enabled and must be present in hardware.
* There will be panic if feature is not present at cold boot.
* ENABLE_FEAT_xxx = 2 : The feature is enabled but dynamically enabled at runtime
* depending on hardware capability.
*
* For better readability, state values are defined with macros, namely:
* { FEAT_STATE_DISABLED, FEAT_STATE_ALWAYS, FEAT_STATE_CHECK }, taking values
* { 0, 1, 2 }, respectively, as their naming.
**********************************************************************************/
void detect_arch_features(void)
{
tainted = false;
/* v8.0 features */
read_feat_sb();
read_feat_csv2_2();
/* v8.1 features */
read_feat_pan();
check_feature(ENABLE_FEAT_VHE, read_feat_vhe_id_field(), "VHE", 1, 1);
/* v8.2 features */
read_feat_ras();
/* v8.3 features */
read_feat_pauth();
/* v8.4 features */
read_feat_dit();
check_feature(ENABLE_FEAT_AMUv1, read_feat_amu_id_field(),
"AMUv1", 1, 2);
check_feature(ENABLE_MPAM_FOR_LOWER_ELS, read_feat_mpam_version(),
"MPAM", 1, 1);
read_feat_nv2();
read_feat_sel2();
check_feature(ENABLE_TRF_FOR_NS, read_feat_trf_id_field(),
"TRF", 1, 1);
/* v8.5 features */
read_feat_mte();
read_feat_rng();
read_feat_bti();
read_feat_rng_trap();
/* v8.6 features */
read_feat_amuv1p1();
check_feature(ENABLE_FEAT_FGT, read_feat_fgt_id_field(), "FGT", 1, 1);
read_feat_ecv();
read_feat_twed();
/* v8.7 features */
check_feature(ENABLE_FEAT_HCX, read_feat_hcx_id_field(), "HCX", 1, 1);
/* v8.9 features */
check_feature(ENABLE_FEAT_TCR2, read_feat_tcrx_id_field(),
"TCR2", 1, 1);
/* v9.0 features */
check_feature(ENABLE_BRBE_FOR_NS, read_feat_brbe_id_field(),
"BRBE", 1, 2);
check_feature(ENABLE_TRBE_FOR_NS, read_feat_trbe_id_field(),
"TRBE", 1, 1);
/* v9.2 features */
read_feat_rme();
if (tainted) {
panic();
}
}