[kvm-unit-tests PATCH v3 2/2] riscv: Add tests for SBI FWFT extension
Clément Léger
cleger at rivosinc.com
Tue Jan 28 06:15:42 PST 2025
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 at 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 at 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();
}
--
2.47.1
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