diff mbox series

[kvm-unit-tests,v3,2/2] riscv: Add tests for SBI FWFT extension

Message ID 20250128141543.1338677-3-cleger@rivosinc.com (mailing list archive)
State New
Headers show
Series Add support for SBI FWFT extension testing | expand

Commit Message

Clément Léger Jan. 28, 2025, 2:15 p.m. UTC 
Add tests for the FWFT SBI extension. Currently, only the reserved range
as well as the misaligned exception delegation are used.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
---
 riscv/Makefile      |   2 +-
 lib/riscv/asm/sbi.h |  34 ++++++++
 riscv/sbi-fwft.c    | 190 ++++++++++++++++++++++++++++++++++++++++++++
 riscv/sbi.c         |   3 +
 4 files changed, 228 insertions(+), 1 deletion(-)
 create mode 100644 riscv/sbi-fwft.c

Comments

Andrew Jones Jan. 29, 2025, 1:47 p.m. UTC | #1 
On Tue, Jan 28, 2025 at 03:15:42PM +0100, Clément Léger wrote:
> Add tests for the FWFT SBI extension. Currently, only the reserved range
> as well as the misaligned exception delegation are used.
> 
> Signed-off-by: Clément Léger <cleger@rivosinc.com>
> ---
>  riscv/Makefile      |   2 +-
>  lib/riscv/asm/sbi.h |  34 ++++++++
>  riscv/sbi-fwft.c    | 190 ++++++++++++++++++++++++++++++++++++++++++++
>  riscv/sbi.c         |   3 +
>  4 files changed, 228 insertions(+), 1 deletion(-)
>  create mode 100644 riscv/sbi-fwft.c
> 
> diff --git a/riscv/Makefile b/riscv/Makefile
> index 5b5e157c..52718f3f 100644
> --- a/riscv/Makefile
> +++ b/riscv/Makefile
> @@ -17,7 +17,7 @@ tests += $(TEST_DIR)/sieve.$(exe)
>  
>  all: $(tests)
>  
> -$(TEST_DIR)/sbi-deps = $(TEST_DIR)/sbi-asm.o
> +$(TEST_DIR)/sbi-deps = $(TEST_DIR)/sbi-asm.o $(TEST_DIR)/sbi-fwft.o
>  
>  # When built for EFI sieve needs extra memory, run with e.g. '-m 256' on QEMU
>  $(TEST_DIR)/sieve.$(exe): AUXFLAGS = 0x1
> diff --git a/lib/riscv/asm/sbi.h b/lib/riscv/asm/sbi.h
> index 98a9b097..397400f2 100644
> --- a/lib/riscv/asm/sbi.h
> +++ b/lib/riscv/asm/sbi.h
> @@ -11,6 +11,12 @@
>  #define SBI_ERR_ALREADY_AVAILABLE	-6
>  #define SBI_ERR_ALREADY_STARTED		-7
>  #define SBI_ERR_ALREADY_STOPPED		-8
> +#define SBI_ERR_NO_SHMEM		-9
> +#define SBI_ERR_INVALID_STATE		-10
> +#define SBI_ERR_BAD_RANGE		-11
> +#define SBI_ERR_TIMEOUT			-12
> +#define SBI_ERR_IO			-13
> +#define SBI_ERR_LOCKED			-14
>  
>  #ifndef __ASSEMBLY__
>  #include <cpumask.h>
> @@ -23,6 +29,7 @@ enum sbi_ext_id {
>  	SBI_EXT_SRST = 0x53525354,
>  	SBI_EXT_DBCN = 0x4442434E,
>  	SBI_EXT_SUSP = 0x53555350,
> +	SBI_EXT_FWFT = 0x46574654,
>  };
>  
>  enum sbi_ext_base_fid {
> @@ -71,6 +78,33 @@ enum sbi_ext_dbcn_fid {
>  	SBI_EXT_DBCN_CONSOLE_WRITE_BYTE,
>  };
>  
> +
> +enum sbi_ext_fwft_fid {
> +	SBI_EXT_FWFT_SET = 0,
> +	SBI_EXT_FWFT_GET,
> +};
> +
> +#define SBI_FWFT_MISALIGNED_EXC_DELEG		0x0
> +#define SBI_FWFT_LANDING_PAD			0x1
> +#define SBI_FWFT_SHADOW_STACK			0x2
> +#define SBI_FWFT_DOUBLE_TRAP			0x3
> +#define SBI_FWFT_PTE_AD_HW_UPDATING		0x4
> +#define SBI_FWFT_POINTER_MASKING_PMLEN		0x5
> +#define SBI_FWFT_LOCAL_RESERVED_START		0x6
> +#define SBI_FWFT_LOCAL_RESERVED_END		0x3fffffff
> +#define SBI_FWFT_LOCAL_PLATFORM_START		0x40000000
> +#define SBI_FWFT_LOCAL_PLATFORM_END		0x7fffffff
> +
> +#define SBI_FWFT_GLOBAL_RESERVED_START		0x80000000
> +#define SBI_FWFT_GLOBAL_RESERVED_END		0xbfffffff
> +#define SBI_FWFT_GLOBAL_PLATFORM_START		0xc0000000
> +#define SBI_FWFT_GLOBAL_PLATFORM_END		0xffffffff
> +
> +#define SBI_FWFT_PLATFORM_FEATURE_BIT		BIT(30)
> +#define SBI_FWFT_GLOBAL_FEATURE_BIT		BIT(31)
> +
> +#define SBI_FWFT_SET_FLAG_LOCK			BIT(0)
> +
>  struct sbiret {
>  	long error;
>  	long value;
> diff --git a/riscv/sbi-fwft.c b/riscv/sbi-fwft.c
> new file mode 100644
> index 00000000..c9292cfb
> --- /dev/null
> +++ b/riscv/sbi-fwft.c
> @@ -0,0 +1,190 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * SBI verification
> + *
> + * Copyright (C) 2024, Rivos Inc., Clément Léger <cleger@rivosinc.com>
> + */
> +#include <libcflat.h>
> +#include <stdlib.h>
> +
> +#include <asm/csr.h>
> +#include <asm/processor.h>
> +#include <asm/ptrace.h>
> +#include <asm/sbi.h>
> +
> +#include "sbi-tests.h"
> +
> +void check_fwft(void);
> +
> +
> +static struct sbiret fwft_set_raw(unsigned long feature, unsigned long value, unsigned long flags)
> +{
> +	return sbi_ecall(SBI_EXT_FWFT, SBI_EXT_FWFT_SET, feature, value, flags, 0, 0, 0);
> +}
> +
> +static struct sbiret fwft_set(uint32_t feature, unsigned long value, unsigned long flags)
> +{
> +	return fwft_set_raw(feature, value, flags);
> +}
> +
> +static struct sbiret fwft_get_raw(unsigned long feature)
> +{
> +	return sbi_ecall(SBI_EXT_FWFT, SBI_EXT_FWFT_GET, feature, 0, 0, 0, 0, 0);
> +}
> +
> +static struct sbiret fwft_get(uint32_t feature)
> +{
> +	return fwft_get_raw(feature);
> +}
> +
> +static void fwft_check_reserved(unsigned long id)
> +{
> +	struct sbiret ret;
> +
> +	ret = fwft_get(id);
> +	sbiret_report_error(&ret, SBI_ERR_DENIED, "get reserved feature 0x%lx", id);
> +
> +	ret = fwft_set(id, 1, 0);
> +	sbiret_report_error(&ret, SBI_ERR_DENIED, "set reserved feature 0x%lx", id);
> +}
> +
> +static void fwft_check_base(void)
> +{
> +	struct sbiret ret;
> +
> +	report_prefix_push("base");
> +
> +	fwft_check_reserved(SBI_FWFT_LOCAL_RESERVED_START);
> +	fwft_check_reserved(SBI_FWFT_LOCAL_RESERVED_END);
> +	fwft_check_reserved(SBI_FWFT_GLOBAL_RESERVED_START);
> +	fwft_check_reserved(SBI_FWFT_GLOBAL_RESERVED_END);
> +
> +	/* Check id > 32 bits */
> +	if (__riscv_xlen > 32) {
> +		ret = fwft_get_raw(BIT(32));
> +		sbiret_report_error(&ret, SBI_ERR_INVALID_PARAM,
> +				    "get feature 0x%lx error", BIT(32));
> +
> +		ret = fwft_set_raw(BIT(32), 0, 0);
> +		sbiret_report_error(&ret, SBI_ERR_INVALID_PARAM,
> +				    "set feature 0x%lx error", BIT(32));
> +	}
> +
> +	report_prefix_pop();
> +}
> +
> +static bool misaligned_handled;
> +
> +static void misaligned_handler(struct pt_regs *regs)
> +{
> +	misaligned_handled = true;
> +	regs->epc += 4;
> +}
> +
> +static struct sbiret fwft_misaligned_exc_set(unsigned long value, unsigned long flags)
> +{
> +	return fwft_set(SBI_FWFT_MISALIGNED_EXC_DELEG, value, flags);
> +}
> +
> +static struct sbiret fwft_misaligned_exc_get(void)
> +{
> +	return fwft_get(SBI_FWFT_MISALIGNED_EXC_DELEG);
> +}
> +
> +static void fwft_check_misaligned_exc_deleg(void)
> +{
> +	struct sbiret ret;
> +
> +	report_prefix_push("misaligned_exc_deleg");
> +
> +	ret = fwft_misaligned_exc_get();
> +	if (ret.error == SBI_ERR_NOT_SUPPORTED) {
> +		report_skip("SBI_FWFT_MISALIGNED_EXC_DELEG is not supported");
> +		return;
> +	}
> +
> +	if (!sbiret_report_error(&ret, 0, "Get misaligned deleg feature no error"))
> +		return;
> +
> +	ret = fwft_misaligned_exc_set(2, 0);
> +	sbiret_report_error(&ret, SBI_ERR_INVALID_PARAM,
> +			    "Set misaligned deleg feature invalid value 2");
> +	ret = fwft_misaligned_exc_set(0xFFFFFFFF, 0);
> +	sbiret_report_error(&ret, SBI_ERR_INVALID_PARAM,
> +			    "Set misaligned deleg feature invalid value 0xFFFFFFFF");
> +
> +	if (__riscv_xlen > 32) {
> +		ret = fwft_misaligned_exc_set(BIT(32), 0);
> +		sbiret_report_error(&ret, SBI_ERR_INVALID_PARAM,
> +				    "Set misaligned deleg with invalid value > 32bits");
> +
> +		ret = fwft_misaligned_exc_set(0, BIT(32));
> +		sbiret_report_error(&ret, SBI_ERR_INVALID_PARAM,
> +				    "Set misaligned deleg with invalid flag > 32bits");
> +	}
> +
> +	/* Set to 0 and check after with get */
> +	ret = fwft_misaligned_exc_set(0, 0);
> +	sbiret_report_error(&ret, 0, "Set misaligned deleg feature value 0 no error");
> +	ret = fwft_misaligned_exc_get();
> +	sbiret_report(&ret, 0, 0, "Get misaligned deleg feature expected value 0");
> +
> +	/* Set to 1 and check after with get */
> +	ret = fwft_misaligned_exc_set(1, 0);
> +	sbiret_report_error(&ret, 0, "Set misaligned deleg feature value 1 no error");
> +	ret = fwft_misaligned_exc_get();
> +	sbiret_report(&ret, 0, 1, "Get misaligned deleg feature expected value 1");
> +
> +	install_exception_handler(EXC_LOAD_MISALIGNED, misaligned_handler);
> +
> +	asm volatile (
> +		".option push\n"
> +		/*
> +		 * Disable compression so the lw takes exactly 4 bytes and thus
> +		 * can be skipped reliably from the exception handler.
> +		 */
> +		".option arch,-c\n"
> +		"lw %[val], 1(%[val_addr])\n"
> +		".option pop\n"
> +		: [val] "+r" (ret.value)
> +		: [val_addr] "r" (&ret.value)
> +		: "memory");
> +
> +	/*
> +	 * Even though the SBI delegated the misaligned exception to S-mode, it might not trap on
> +	 * misaligned load/store access, report that during tests.
> +	 */
> +	if (!misaligned_handled)
> +		report_skip("Misaligned load exception does not trap in S-mode");
> +	else
> +		report_pass("Misaligned load exception trap in S-mode");
> +
> +	install_exception_handler(EXC_LOAD_MISALIGNED, NULL);
> +
> +	/* Lock the feature */
> +	ret = fwft_misaligned_exc_set(0, SBI_FWFT_SET_FLAG_LOCK);
> +	sbiret_report_error(&ret, 0, "Set misaligned deleg feature value 0 and lock no error");
> +	ret = fwft_misaligned_exc_set(1, 0);
> +	sbiret_report_error(&ret, SBI_ERR_LOCKED,
> +			    "Set misaligned deleg feature value 0 and lock no error");

The error message is copy+pasted from the last one. I've changed it to

"Set locked misaligned deleg feature to new value returns error"

while merging.

> +	ret = fwft_misaligned_exc_get();
> +	sbiret_report(&ret, 0, 0, "Get misaligned deleg locked value 0 no error");
> +
> +	report_prefix_pop();
> +}
> +
> +void check_fwft(void)
> +{
> +	report_prefix_push("fwft");
> +
> +	if (!sbi_probe(SBI_EXT_FWFT)) {
> +		report_skip("FWFT extension not available");
> +		report_prefix_pop();
> +		return;
> +	}
> +
> +	fwft_check_base();
> +	fwft_check_misaligned_exc_deleg();
> +
> +	report_prefix_pop();
> +}
> diff --git a/riscv/sbi.c b/riscv/sbi.c
> index 3eca8c7e..7c7a2d2d 100644
> --- a/riscv/sbi.c
> +++ b/riscv/sbi.c
> @@ -32,6 +32,8 @@
>  
>  #define	HIGH_ADDR_BOUNDARY	((phys_addr_t)1 << 32)
>  
> +void check_fwft(void);
> +
>  static long __labs(long a)
>  {
>  	return __builtin_labs(a);
> @@ -1437,6 +1439,7 @@ int main(int argc, char **argv)
>  	check_hsm();
>  	check_dbcn();
>  	check_susp();
> +	check_fwft();
>  
>  	return report_summary();
>  }
> -- 
> 2.47.1
>

Thanks,
drew
Andrew Jones Jan. 29, 2025, 2:17 p.m. UTC | #2 
On Tue, Jan 28, 2025 at 03:15:42PM +0100, Clément Léger wrote:
> Add tests for the FWFT SBI extension. Currently, only the reserved range
> as well as the misaligned exception delegation are used.
> 
> Signed-off-by: Clément Léger <cleger@rivosinc.com>
> ---
>  riscv/Makefile      |   2 +-
>  lib/riscv/asm/sbi.h |  34 ++++++++
>  riscv/sbi-fwft.c    | 190 ++++++++++++++++++++++++++++++++++++++++++++
>  riscv/sbi.c         |   3 +
>  4 files changed, 228 insertions(+), 1 deletion(-)
>  create mode 100644 riscv/sbi-fwft.c
> 
> diff --git a/riscv/Makefile b/riscv/Makefile
> index 5b5e157c..52718f3f 100644
> --- a/riscv/Makefile
> +++ b/riscv/Makefile
> @@ -17,7 +17,7 @@ tests += $(TEST_DIR)/sieve.$(exe)
>  
>  all: $(tests)
>  
> -$(TEST_DIR)/sbi-deps = $(TEST_DIR)/sbi-asm.o
> +$(TEST_DIR)/sbi-deps = $(TEST_DIR)/sbi-asm.o $(TEST_DIR)/sbi-fwft.o
>  
>  # When built for EFI sieve needs extra memory, run with e.g. '-m 256' on QEMU
>  $(TEST_DIR)/sieve.$(exe): AUXFLAGS = 0x1
> diff --git a/lib/riscv/asm/sbi.h b/lib/riscv/asm/sbi.h
> index 98a9b097..397400f2 100644
> --- a/lib/riscv/asm/sbi.h
> +++ b/lib/riscv/asm/sbi.h
> @@ -11,6 +11,12 @@
>  #define SBI_ERR_ALREADY_AVAILABLE	-6
>  #define SBI_ERR_ALREADY_STARTED		-7
>  #define SBI_ERR_ALREADY_STOPPED		-8
> +#define SBI_ERR_NO_SHMEM		-9
> +#define SBI_ERR_INVALID_STATE		-10
> +#define SBI_ERR_BAD_RANGE		-11
> +#define SBI_ERR_TIMEOUT			-12
> +#define SBI_ERR_IO			-13
> +#define SBI_ERR_LOCKED			-14
>  
>  #ifndef __ASSEMBLY__
>  #include <cpumask.h>
> @@ -23,6 +29,7 @@ enum sbi_ext_id {
>  	SBI_EXT_SRST = 0x53525354,
>  	SBI_EXT_DBCN = 0x4442434E,
>  	SBI_EXT_SUSP = 0x53555350,
> +	SBI_EXT_FWFT = 0x46574654,
>  };
>  
>  enum sbi_ext_base_fid {
> @@ -71,6 +78,33 @@ enum sbi_ext_dbcn_fid {
>  	SBI_EXT_DBCN_CONSOLE_WRITE_BYTE,
>  };
>  
> +
> +enum sbi_ext_fwft_fid {
> +	SBI_EXT_FWFT_SET = 0,
> +	SBI_EXT_FWFT_GET,
> +};
> +
> +#define SBI_FWFT_MISALIGNED_EXC_DELEG		0x0
> +#define SBI_FWFT_LANDING_PAD			0x1
> +#define SBI_FWFT_SHADOW_STACK			0x2
> +#define SBI_FWFT_DOUBLE_TRAP			0x3
> +#define SBI_FWFT_PTE_AD_HW_UPDATING		0x4
> +#define SBI_FWFT_POINTER_MASKING_PMLEN		0x5
> +#define SBI_FWFT_LOCAL_RESERVED_START		0x6
> +#define SBI_FWFT_LOCAL_RESERVED_END		0x3fffffff
> +#define SBI_FWFT_LOCAL_PLATFORM_START		0x40000000
> +#define SBI_FWFT_LOCAL_PLATFORM_END		0x7fffffff
> +
> +#define SBI_FWFT_GLOBAL_RESERVED_START		0x80000000
> +#define SBI_FWFT_GLOBAL_RESERVED_END		0xbfffffff
> +#define SBI_FWFT_GLOBAL_PLATFORM_START		0xc0000000
> +#define SBI_FWFT_GLOBAL_PLATFORM_END		0xffffffff
> +
> +#define SBI_FWFT_PLATFORM_FEATURE_BIT		BIT(30)
> +#define SBI_FWFT_GLOBAL_FEATURE_BIT		BIT(31)
> +
> +#define SBI_FWFT_SET_FLAG_LOCK			BIT(0)
> +
>  struct sbiret {
>  	long error;
>  	long value;
> diff --git a/riscv/sbi-fwft.c b/riscv/sbi-fwft.c
> new file mode 100644
> index 00000000..c9292cfb
> --- /dev/null
> +++ b/riscv/sbi-fwft.c
> @@ -0,0 +1,190 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * SBI verification
> + *
> + * Copyright (C) 2024, Rivos Inc., Clément Léger <cleger@rivosinc.com>
> + */
> +#include <libcflat.h>
> +#include <stdlib.h>
> +
> +#include <asm/csr.h>
> +#include <asm/processor.h>
> +#include <asm/ptrace.h>
> +#include <asm/sbi.h>
> +
> +#include "sbi-tests.h"
> +
> +void check_fwft(void);
> +
> +
> +static struct sbiret fwft_set_raw(unsigned long feature, unsigned long value, unsigned long flags)
> +{
> +	return sbi_ecall(SBI_EXT_FWFT, SBI_EXT_FWFT_SET, feature, value, flags, 0, 0, 0);
> +}
> +
> +static struct sbiret fwft_set(uint32_t feature, unsigned long value, unsigned long flags)
> +{
> +	return fwft_set_raw(feature, value, flags);
> +}
> +
> +static struct sbiret fwft_get_raw(unsigned long feature)
> +{
> +	return sbi_ecall(SBI_EXT_FWFT, SBI_EXT_FWFT_GET, feature, 0, 0, 0, 0, 0);
> +}
> +
> +static struct sbiret fwft_get(uint32_t feature)
> +{
> +	return fwft_get_raw(feature);
> +}
> +
> +static void fwft_check_reserved(unsigned long id)
> +{
> +	struct sbiret ret;
> +
> +	ret = fwft_get(id);
> +	sbiret_report_error(&ret, SBI_ERR_DENIED, "get reserved feature 0x%lx", id);
> +
> +	ret = fwft_set(id, 1, 0);
> +	sbiret_report_error(&ret, SBI_ERR_DENIED, "set reserved feature 0x%lx", id);
> +}
> +
> +static void fwft_check_base(void)
> +{
> +	struct sbiret ret;
> +
> +	report_prefix_push("base");
> +
> +	fwft_check_reserved(SBI_FWFT_LOCAL_RESERVED_START);
> +	fwft_check_reserved(SBI_FWFT_LOCAL_RESERVED_END);
> +	fwft_check_reserved(SBI_FWFT_GLOBAL_RESERVED_START);
> +	fwft_check_reserved(SBI_FWFT_GLOBAL_RESERVED_END);
> +
> +	/* Check id > 32 bits */
> +	if (__riscv_xlen > 32) {
> +		ret = fwft_get_raw(BIT(32));
> +		sbiret_report_error(&ret, SBI_ERR_INVALID_PARAM,
> +				    "get feature 0x%lx error", BIT(32));
> +
> +		ret = fwft_set_raw(BIT(32), 0, 0);
> +		sbiret_report_error(&ret, SBI_ERR_INVALID_PARAM,
> +				    "set feature 0x%lx error", BIT(32));

At least with the compiler I'm using, the code inside this
"if (__riscv_xlen > 32)" block is still getting compiled for
rv32 and breaking on the BIT(). It doesn't help to use BIT_ULL() here
since fwft_get/set_raw() take longs. I guess we'll have to use #if.

Fixed on merge.

> +	}
> +
> +	report_prefix_pop();
> +}
> +
> +static bool misaligned_handled;
> +
> +static void misaligned_handler(struct pt_regs *regs)
> +{
> +	misaligned_handled = true;
> +	regs->epc += 4;
> +}
> +
> +static struct sbiret fwft_misaligned_exc_set(unsigned long value, unsigned long flags)
> +{
> +	return fwft_set(SBI_FWFT_MISALIGNED_EXC_DELEG, value, flags);
> +}
> +
> +static struct sbiret fwft_misaligned_exc_get(void)
> +{
> +	return fwft_get(SBI_FWFT_MISALIGNED_EXC_DELEG);
> +}
> +
> +static void fwft_check_misaligned_exc_deleg(void)
> +{
> +	struct sbiret ret;
> +
> +	report_prefix_push("misaligned_exc_deleg");
> +
> +	ret = fwft_misaligned_exc_get();
> +	if (ret.error == SBI_ERR_NOT_SUPPORTED) {
> +		report_skip("SBI_FWFT_MISALIGNED_EXC_DELEG is not supported");
> +		return;
> +	}
> +
> +	if (!sbiret_report_error(&ret, 0, "Get misaligned deleg feature no error"))
> +		return;
> +
> +	ret = fwft_misaligned_exc_set(2, 0);
> +	sbiret_report_error(&ret, SBI_ERR_INVALID_PARAM,
> +			    "Set misaligned deleg feature invalid value 2");
> +	ret = fwft_misaligned_exc_set(0xFFFFFFFF, 0);
> +	sbiret_report_error(&ret, SBI_ERR_INVALID_PARAM,
> +			    "Set misaligned deleg feature invalid value 0xFFFFFFFF");
> +
> +	if (__riscv_xlen > 32) {
> +		ret = fwft_misaligned_exc_set(BIT(32), 0);
> +		sbiret_report_error(&ret, SBI_ERR_INVALID_PARAM,
> +				    "Set misaligned deleg with invalid value > 32bits");
> +
> +		ret = fwft_misaligned_exc_set(0, BIT(32));
> +		sbiret_report_error(&ret, SBI_ERR_INVALID_PARAM,
> +				    "Set misaligned deleg with invalid flag > 32bits");

Same comment as above and also fixed on merge.

Thanks,
drew
diff mbox series

Patch

diff --git a/riscv/Makefile b/riscv/Makefile
index 5b5e157c..52718f3f 100644
--- a/riscv/Makefile
+++ b/riscv/Makefile
@@ -17,7 +17,7 @@  tests += $(TEST_DIR)/sieve.$(exe)
 
 all: $(tests)
 
-$(TEST_DIR)/sbi-deps = $(TEST_DIR)/sbi-asm.o
+$(TEST_DIR)/sbi-deps = $(TEST_DIR)/sbi-asm.o $(TEST_DIR)/sbi-fwft.o
 
 # When built for EFI sieve needs extra memory, run with e.g. '-m 256' on QEMU
 $(TEST_DIR)/sieve.$(exe): AUXFLAGS = 0x1
diff --git a/lib/riscv/asm/sbi.h b/lib/riscv/asm/sbi.h
index 98a9b097..397400f2 100644
--- a/lib/riscv/asm/sbi.h
+++ b/lib/riscv/asm/sbi.h
@@ -11,6 +11,12 @@ 
 #define SBI_ERR_ALREADY_AVAILABLE	-6
 #define SBI_ERR_ALREADY_STARTED		-7
 #define SBI_ERR_ALREADY_STOPPED		-8
+#define SBI_ERR_NO_SHMEM		-9
+#define SBI_ERR_INVALID_STATE		-10
+#define SBI_ERR_BAD_RANGE		-11
+#define SBI_ERR_TIMEOUT			-12
+#define SBI_ERR_IO			-13
+#define SBI_ERR_LOCKED			-14
 
 #ifndef __ASSEMBLY__
 #include <cpumask.h>
@@ -23,6 +29,7 @@  enum sbi_ext_id {
 	SBI_EXT_SRST = 0x53525354,
 	SBI_EXT_DBCN = 0x4442434E,
 	SBI_EXT_SUSP = 0x53555350,
+	SBI_EXT_FWFT = 0x46574654,
 };
 
 enum sbi_ext_base_fid {
@@ -71,6 +78,33 @@  enum sbi_ext_dbcn_fid {
 	SBI_EXT_DBCN_CONSOLE_WRITE_BYTE,
 };
 
+
+enum sbi_ext_fwft_fid {
+	SBI_EXT_FWFT_SET = 0,
+	SBI_EXT_FWFT_GET,
+};
+
+#define SBI_FWFT_MISALIGNED_EXC_DELEG		0x0
+#define SBI_FWFT_LANDING_PAD			0x1
+#define SBI_FWFT_SHADOW_STACK			0x2
+#define SBI_FWFT_DOUBLE_TRAP			0x3
+#define SBI_FWFT_PTE_AD_HW_UPDATING		0x4
+#define SBI_FWFT_POINTER_MASKING_PMLEN		0x5
+#define SBI_FWFT_LOCAL_RESERVED_START		0x6
+#define SBI_FWFT_LOCAL_RESERVED_END		0x3fffffff
+#define SBI_FWFT_LOCAL_PLATFORM_START		0x40000000
+#define SBI_FWFT_LOCAL_PLATFORM_END		0x7fffffff
+
+#define SBI_FWFT_GLOBAL_RESERVED_START		0x80000000
+#define SBI_FWFT_GLOBAL_RESERVED_END		0xbfffffff
+#define SBI_FWFT_GLOBAL_PLATFORM_START		0xc0000000
+#define SBI_FWFT_GLOBAL_PLATFORM_END		0xffffffff
+
+#define SBI_FWFT_PLATFORM_FEATURE_BIT		BIT(30)
+#define SBI_FWFT_GLOBAL_FEATURE_BIT		BIT(31)
+
+#define SBI_FWFT_SET_FLAG_LOCK			BIT(0)
+
 struct sbiret {
 	long error;
 	long value;
diff --git a/riscv/sbi-fwft.c b/riscv/sbi-fwft.c
new file mode 100644
index 00000000..c9292cfb
--- /dev/null
+++ b/riscv/sbi-fwft.c
@@ -0,0 +1,190 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * SBI verification
+ *
+ * Copyright (C) 2024, Rivos Inc., Clément Léger <cleger@rivosinc.com>
+ */
+#include <libcflat.h>
+#include <stdlib.h>
+
+#include <asm/csr.h>
+#include <asm/processor.h>
+#include <asm/ptrace.h>
+#include <asm/sbi.h>
+
+#include "sbi-tests.h"
+
+void check_fwft(void);
+
+
+static struct sbiret fwft_set_raw(unsigned long feature, unsigned long value, unsigned long flags)
+{
+	return sbi_ecall(SBI_EXT_FWFT, SBI_EXT_FWFT_SET, feature, value, flags, 0, 0, 0);
+}
+
+static struct sbiret fwft_set(uint32_t feature, unsigned long value, unsigned long flags)
+{
+	return fwft_set_raw(feature, value, flags);
+}
+
+static struct sbiret fwft_get_raw(unsigned long feature)
+{
+	return sbi_ecall(SBI_EXT_FWFT, SBI_EXT_FWFT_GET, feature, 0, 0, 0, 0, 0);
+}
+
+static struct sbiret fwft_get(uint32_t feature)
+{
+	return fwft_get_raw(feature);
+}
+
+static void fwft_check_reserved(unsigned long id)
+{
+	struct sbiret ret;
+
+	ret = fwft_get(id);
+	sbiret_report_error(&ret, SBI_ERR_DENIED, "get reserved feature 0x%lx", id);
+
+	ret = fwft_set(id, 1, 0);
+	sbiret_report_error(&ret, SBI_ERR_DENIED, "set reserved feature 0x%lx", id);
+}
+
+static void fwft_check_base(void)
+{
+	struct sbiret ret;
+
+	report_prefix_push("base");
+
+	fwft_check_reserved(SBI_FWFT_LOCAL_RESERVED_START);
+	fwft_check_reserved(SBI_FWFT_LOCAL_RESERVED_END);
+	fwft_check_reserved(SBI_FWFT_GLOBAL_RESERVED_START);
+	fwft_check_reserved(SBI_FWFT_GLOBAL_RESERVED_END);
+
+	/* Check id > 32 bits */
+	if (__riscv_xlen > 32) {
+		ret = fwft_get_raw(BIT(32));
+		sbiret_report_error(&ret, SBI_ERR_INVALID_PARAM,
+				    "get feature 0x%lx error", BIT(32));
+
+		ret = fwft_set_raw(BIT(32), 0, 0);
+		sbiret_report_error(&ret, SBI_ERR_INVALID_PARAM,
+				    "set feature 0x%lx error", BIT(32));
+	}
+
+	report_prefix_pop();
+}
+
+static bool misaligned_handled;
+
+static void misaligned_handler(struct pt_regs *regs)
+{
+	misaligned_handled = true;
+	regs->epc += 4;
+}
+
+static struct sbiret fwft_misaligned_exc_set(unsigned long value, unsigned long flags)
+{
+	return fwft_set(SBI_FWFT_MISALIGNED_EXC_DELEG, value, flags);
+}
+
+static struct sbiret fwft_misaligned_exc_get(void)
+{
+	return fwft_get(SBI_FWFT_MISALIGNED_EXC_DELEG);
+}
+
+static void fwft_check_misaligned_exc_deleg(void)
+{
+	struct sbiret ret;
+
+	report_prefix_push("misaligned_exc_deleg");
+
+	ret = fwft_misaligned_exc_get();
+	if (ret.error == SBI_ERR_NOT_SUPPORTED) {
+		report_skip("SBI_FWFT_MISALIGNED_EXC_DELEG is not supported");
+		return;
+	}
+
+	if (!sbiret_report_error(&ret, 0, "Get misaligned deleg feature no error"))
+		return;
+
+	ret = fwft_misaligned_exc_set(2, 0);
+	sbiret_report_error(&ret, SBI_ERR_INVALID_PARAM,
+			    "Set misaligned deleg feature invalid value 2");
+	ret = fwft_misaligned_exc_set(0xFFFFFFFF, 0);
+	sbiret_report_error(&ret, SBI_ERR_INVALID_PARAM,
+			    "Set misaligned deleg feature invalid value 0xFFFFFFFF");
+
+	if (__riscv_xlen > 32) {
+		ret = fwft_misaligned_exc_set(BIT(32), 0);
+		sbiret_report_error(&ret, SBI_ERR_INVALID_PARAM,
+				    "Set misaligned deleg with invalid value > 32bits");
+
+		ret = fwft_misaligned_exc_set(0, BIT(32));
+		sbiret_report_error(&ret, SBI_ERR_INVALID_PARAM,
+				    "Set misaligned deleg with invalid flag > 32bits");
+	}
+
+	/* Set to 0 and check after with get */
+	ret = fwft_misaligned_exc_set(0, 0);
+	sbiret_report_error(&ret, 0, "Set misaligned deleg feature value 0 no error");
+	ret = fwft_misaligned_exc_get();
+	sbiret_report(&ret, 0, 0, "Get misaligned deleg feature expected value 0");
+
+	/* Set to 1 and check after with get */
+	ret = fwft_misaligned_exc_set(1, 0);
+	sbiret_report_error(&ret, 0, "Set misaligned deleg feature value 1 no error");
+	ret = fwft_misaligned_exc_get();
+	sbiret_report(&ret, 0, 1, "Get misaligned deleg feature expected value 1");
+
+	install_exception_handler(EXC_LOAD_MISALIGNED, misaligned_handler);
+
+	asm volatile (
+		".option push\n"
+		/*
+		 * Disable compression so the lw takes exactly 4 bytes and thus
+		 * can be skipped reliably from the exception handler.
+		 */
+		".option arch,-c\n"
+		"lw %[val], 1(%[val_addr])\n"
+		".option pop\n"
+		: [val] "+r" (ret.value)
+		: [val_addr] "r" (&ret.value)
+		: "memory");
+
+	/*
+	 * Even though the SBI delegated the misaligned exception to S-mode, it might not trap on
+	 * misaligned load/store access, report that during tests.
+	 */
+	if (!misaligned_handled)
+		report_skip("Misaligned load exception does not trap in S-mode");
+	else
+		report_pass("Misaligned load exception trap in S-mode");
+
+	install_exception_handler(EXC_LOAD_MISALIGNED, NULL);
+
+	/* Lock the feature */
+	ret = fwft_misaligned_exc_set(0, SBI_FWFT_SET_FLAG_LOCK);
+	sbiret_report_error(&ret, 0, "Set misaligned deleg feature value 0 and lock no error");
+	ret = fwft_misaligned_exc_set(1, 0);
+	sbiret_report_error(&ret, SBI_ERR_LOCKED,
+			    "Set misaligned deleg feature value 0 and lock no error");
+	ret = fwft_misaligned_exc_get();
+	sbiret_report(&ret, 0, 0, "Get misaligned deleg locked value 0 no error");
+
+	report_prefix_pop();
+}
+
+void check_fwft(void)
+{
+	report_prefix_push("fwft");
+
+	if (!sbi_probe(SBI_EXT_FWFT)) {
+		report_skip("FWFT extension not available");
+		report_prefix_pop();
+		return;
+	}
+
+	fwft_check_base();
+	fwft_check_misaligned_exc_deleg();
+
+	report_prefix_pop();
+}
diff --git a/riscv/sbi.c b/riscv/sbi.c
index 3eca8c7e..7c7a2d2d 100644
--- a/riscv/sbi.c
+++ b/riscv/sbi.c
@@ -32,6 +32,8 @@ 
 
 #define	HIGH_ADDR_BOUNDARY	((phys_addr_t)1 << 32)
 
+void check_fwft(void);
+
 static long __labs(long a)
 {
 	return __builtin_labs(a);
@@ -1437,6 +1439,7 @@  int main(int argc, char **argv)
 	check_hsm();
 	check_dbcn();
 	check_susp();
+	check_fwft();
 
 	return report_summary();
 }