[kvm-unit-tests PATCH v8 19/35] powerpc: general interrupt tests

Nicholas Piggin
2024-04-05T08:37:08Z

Add basic testing of various kinds of interrupts, machine check,
page fault, illegal, decrementer, trace, syscall, etc.

This has a known failure on QEMU TCG pseries machines where MSR[ME]
can be incorrectly set to 0.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
lib/powerpc/asm/processor.h | 4 +
lib/powerpc/asm/reg.h | 17 ++
lib/powerpc/setup.c | 11 +
lib/ppc64/asm/ptrace.h | 16 ++
powerpc/Makefile.common | 3 +-
powerpc/interrupts.c | 414 ++++++++++++++++++++++++++++++++++++
powerpc/unittests.cfg | 3 +
7 files changed, 467 insertions(+), 1 deletion(-)
create mode 100644 powerpc/interrupts.c

diff --git a/lib/powerpc/asm/processor.h b/lib/powerpc/asm/processor.h
index cf1b9d8ff..eed37d1f4 100644
--- a/lib/powerpc/asm/processor.h
+++ b/lib/powerpc/asm/processor.h
@@ -11,7 +11,11 @@ void do_handle_exception(struct pt_regs *regs);
#endif /* __ASSEMBLY__ */

extern bool cpu_has_hv;
+extern bool cpu_has_power_mce;
+extern bool cpu_has_siar;
extern bool cpu_has_heai;
+extern bool cpu_has_prefix;
+extern bool cpu_has_sc_lev;

static inline uint64_t mfspr(int nr)
{
diff --git a/lib/powerpc/asm/reg.h b/lib/powerpc/asm/reg.h
index 782e75527..d6097f48f 100644
--- a/lib/powerpc/asm/reg.h
+++ b/lib/powerpc/asm/reg.h
@@ -5,8 +5,15 @@

#define UL(x) _AC(x, UL)

+#define SPR_DSISR 0x012
+#define SPR_DAR 0x013
+#define SPR_DEC 0x016
#define SPR_SRR0 0x01a
#define SPR_SRR1 0x01b
+#define SRR1_PREFIX UL(0x20000000)
+#define SPR_FSCR 0x099
+#define FSCR_PREFIX UL(0x2000)
+#define SPR_HFSCR 0x0be
#define SPR_TB 0x10c
#define SPR_SPRG0 0x110
#define SPR_SPRG1 0x111
@@ -22,12 +29,17 @@
#define PVR_VER_POWER8 UL(0x004d0000)
#define PVR_VER_POWER9 UL(0x004e0000)
#define PVR_VER_POWER10 UL(0x00800000)
+#define SPR_HDEC 0x136
#define SPR_HSRR0 0x13a
#define SPR_HSRR1 0x13b
+#define SPR_LPCR 0x13e
+#define LPCR_HDICE UL(0x1)
+#define SPR_HEIR 0x153
#define SPR_MMCR0 0x31b
#define MMCR0_FC UL(0x80000000)
#define MMCR0_PMAE UL(0x04000000)
#define MMCR0_PMAO UL(0x00000080)
+#define SPR_SIAR 0x31c

/* Machine State Register definitions: */
#define MSR_LE_BIT 0
@@ -35,6 +47,11 @@
#define MSR_HV_BIT 60 /* Hypervisor mode */
#define MSR_SF_BIT 63 /* 64-bit mode */

+#define MSR_DR UL(0x0010)
+#define MSR_IR UL(0x0020)
+#define MSR_BE UL(0x0200) /* Branch Trace Enable */
+#define MSR_SE UL(0x0400) /* Single Step Enable */
+#define MSR_EE UL(0x8000)
#define MSR_ME UL(0x1000)

#endif
diff --git a/lib/powerpc/setup.c b/lib/powerpc/setup.c
index 3c81aee9e..9b665f59c 100644
--- a/lib/powerpc/setup.c
+++ b/lib/powerpc/setup.c
@@ -87,7 +87,11 @@ static void cpu_set(int fdtnode, u64 regval, void *info)
}

bool cpu_has_hv;
+bool cpu_has_power_mce; /* POWER CPU machine checks */
+bool cpu_has_siar;
bool cpu_has_heai;
+bool cpu_has_prefix;
+bool cpu_has_sc_lev; /* sc interrupt has LEV field in SRR1 */

static void cpu_init(void)
{
@@ -112,15 +116,22 @@ static void cpu_init(void)

switch (mfspr(SPR_PVR) & PVR_VERSION_MASK) {
case PVR_VER_POWER10:
+ cpu_has_prefix = true;
+ cpu_has_sc_lev = true;
case PVR_VER_POWER9:
case PVR_VER_POWER8E:
case PVR_VER_POWER8NVL:
case PVR_VER_POWER8:
+ cpu_has_power_mce = true;
cpu_has_heai = true;
+ cpu_has_siar = true;
break;
default:
break;
}
+
+ if (!cpu_has_hv) /* HEIR is HV register */
+ cpu_has_heai = false;
}

static void mem_init(phys_addr_t freemem_start)
diff --git a/lib/ppc64/asm/ptrace.h b/lib/ppc64/asm/ptrace.h
index 12de7499b..db263a59e 100644
--- a/lib/ppc64/asm/ptrace.h
+++ b/lib/ppc64/asm/ptrace.h
@@ -5,6 +5,9 @@
#define STACK_FRAME_OVERHEAD 112 /* size of minimum stack frame */

#ifndef __ASSEMBLY__
+
+#include <asm/reg.h>
+
struct pt_regs {
unsigned long gpr[32];
unsigned long nip;
@@ -17,6 +20,19 @@ struct pt_regs {
unsigned long _pad; /* stack must be 16-byte aligned */
};

+static inline bool regs_is_prefix(volatile struct pt_regs *regs)
+{
+ return regs->msr & SRR1_PREFIX;
+}
+
+static inline void regs_advance_insn(struct pt_regs *regs)
+{
+ if (regs_is_prefix(regs))
+ regs->nip += 8;
+ else
+ regs->nip += 4;
+}
+
#define STACK_INT_FRAME_SIZE (sizeof(struct pt_regs) + \
STACK_FRAME_OVERHEAD + KERNEL_REDZONE_SIZE)

diff --git a/powerpc/Makefile.common b/powerpc/Makefile.common
index 1e181da69..68165fc25 100644
--- a/powerpc/Makefile.common
+++ b/powerpc/Makefile.common
@@ -12,7 +12,8 @@ tests-common = \
$(TEST_DIR)/rtas.elf \
$(TEST_DIR)/emulator.elf \
$(TEST_DIR)/tm.elf \
- $(TEST_DIR)/sprs.elf
+ $(TEST_DIR)/sprs.elf \
+ $(TEST_DIR)/interrupts.elf

tests-all = $(tests-common) $(tests)
all: directories $(TEST_DIR)/boot_rom.bin $(tests-all)
diff --git a/powerpc/interrupts.c b/powerpc/interrupts.c
new file mode 100644
index 000000000..552c48ef2
--- /dev/null
+++ b/powerpc/interrupts.c
@@ -0,0 +1,414 @@
+/* SPDX-License-Identifier: LGPL-2.0-only */
+/*
+ * Test interrupts
+ *
+ * Copyright 2024 Nicholas Piggin, IBM Corp.
+ */
+#include <libcflat.h>
+#include <util.h>
+#include <migrate.h>
+#include <alloc.h>
+#include <asm/setup.h>
+#include <asm/handlers.h>
+#include <asm/hcall.h>
+#include <asm/processor.h>
+#include <asm/time.h>
+#include <asm/barrier.h>
+
+static volatile bool got_interrupt;
+static volatile struct pt_regs recorded_regs;
+
+static void mce_handler(struct pt_regs *regs, void *opaque)
+{
+ bool *is_fetch = opaque;
+
+ got_interrupt = true;
+ memcpy((void *)&recorded_regs, regs, sizeof(struct pt_regs));
+ if (*is_fetch)
+ regs->nip = regs->link;
+ else
+ regs_advance_insn(regs);
+}
+
+static void fault_handler(struct pt_regs *regs, void *opaque)
+{
+ memcpy((void *)&recorded_regs, regs, sizeof(struct pt_regs));
+ if (regs->trap == 0x400 || regs->trap == 0x480)
+ regs->nip = regs->link;
+ else
+ regs_advance_insn(regs);
+}
+
+static void test_mce(void)
+{
+ unsigned long addr = -4ULL;
+ uint8_t tmp;
+ bool is_fetch;
+
+ report_prefix_push("mce");
+
+ handle_exception(0x200, mce_handler, &is_fetch);
+ handle_exception(0x300, fault_handler, NULL);
+ handle_exception(0x380, fault_handler, NULL);
+ handle_exception(0x400, fault_handler, NULL);
+ handle_exception(0x480, fault_handler, NULL);
+
+ if (machine_is_powernv()) {
+ enable_mcheck();
+ } else {
+ report(mfmsr() & MSR_ME, "pseries machine has MSR[ME]=1");
+ if (!(mfmsr() & MSR_ME)) { /* try to fix it */
+ enable_mcheck();
+ }
+ if (mfmsr() & MSR_ME) {
+ disable_mcheck();
+ report(mfmsr() & MSR_ME, "pseries is unable to change MSR[ME]");
+ if (!(mfmsr() & MSR_ME)) { /* try to fix it */
+ enable_mcheck();
+ }
+ }
+ }
+
+ is_fetch = false;
+ asm volatile("lbz %0,0(%1)" : "=r"(tmp) : "r"(addr));
+
+ report(got_interrupt, "MCE on access to invalid real address");
+ if (got_interrupt) {
+ report(mfspr(SPR_DAR) == addr, "MCE sets DAR correctly");
+ if (cpu_has_power_mce)
+ report(recorded_regs.msr & (1ULL << 21), "d-side MCE sets SRR1[42]");
+ got_interrupt = false;
+ }
+
+ is_fetch = true;
+ asm volatile("mtctr %0 ; bctrl" :: "r"(addr) : "ctr", "lr");
+ report(got_interrupt, "MCE on fetch from invalid real address");
+ if (got_interrupt) {
+ report(recorded_regs.nip == addr, "MCE sets SRR0 correctly");
+ if (cpu_has_power_mce)
+ report(!(recorded_regs.msr & (1ULL << 21)), "i-side MCE clears SRR1[42]");
+ got_interrupt = false;
+ }
+
+ handle_exception(0x200, NULL, NULL);
+ handle_exception(0x300, NULL, NULL);
+ handle_exception(0x380, NULL, NULL);
+ handle_exception(0x400, NULL, NULL);
+ handle_exception(0x480, NULL, NULL);
+
+ report_prefix_pop();
+}
+
+static void dseg_handler(struct pt_regs *regs, void *data)
+{
+ got_interrupt = true;
+ memcpy((void *)&recorded_regs, regs, sizeof(struct pt_regs));
+ regs_advance_insn(regs);
+ regs->msr &= ~MSR_DR;
+}
+
+static void test_dseg(void)
+{
+ uint64_t msr, tmp;
+
+ report_prefix_push("data segment");
+
+ /* Some HV start in radix mode and need 0x300 */
+ handle_exception(0x300, &dseg_handler, NULL);
+ handle_exception(0x380, &dseg_handler, NULL);
+
+ asm volatile(
+" mfmsr %0 \n \
+ ori %0,%0,%2 \n \
+ mtmsrd %0 \n \
+ lbz %1,0(0) "
+ : "=r"(msr), "=r"(tmp) : "i"(MSR_DR): "memory");
+
+ report(got_interrupt, "interrupt on NULL dereference");
+ got_interrupt = false;
+
+ handle_exception(0x300, NULL, NULL);
+ handle_exception(0x380, NULL, NULL);
+
+ report_prefix_pop();
+}
+
+static void dec_handler(struct pt_regs *regs, void *data)
+{
+ got_interrupt = true;
+ memcpy((void *)&recorded_regs, regs, sizeof(struct pt_regs));
+ regs->msr &= ~MSR_EE;
+}
+
+static void test_dec(void)
+{
+ uint64_t msr;
+ uint64_t tb;
+
+ report_prefix_push("decrementer");
+
+ handle_exception(0x900, &dec_handler, NULL);
+
+ asm volatile(
+" mtdec %1 \n \
+ mfmsr %0 \n \
+ ori %0,%0,%2 \n \
+ mtmsrd %0,1 "
+ : "=r"(msr) : "r"(10000), "i"(MSR_EE): "memory");
+
+ tb = get_tb();
+ while (!got_interrupt) {
+ if (get_tb() - tb > tb_hz * 5)
+ break; /* timeout 5s */
+ }
+
+ report(got_interrupt, "interrupt on decrementer underflow");
+ got_interrupt = false;
+
+ handle_exception(0x900, NULL, NULL);
+
+ if (!machine_is_powernv())
+ goto done; /* Skip HV tests */
+
+ handle_exception(0x980, &dec_handler, NULL);
+
+ mtspr(SPR_LPCR, mfspr(SPR_LPCR) | LPCR_HDICE);
+ asm volatile(
+" mtspr 0x136,%1 \n \
+ mtdec %3 \n \
+ mfmsr %0 \n \
+ ori %0,%0,%2 \n \
+ mtmsrd %0,1 "
+ : "=r"(msr) : "r"(10000), "i"(MSR_EE), "r"(0x7fffffff): "memory");
+
+ tb = get_tb();
+ while (!got_interrupt) {
+ if (get_tb() - tb > tb_hz * 5)
+ break; /* timeout 5s */
+ }
+
+ mtspr(SPR_LPCR, mfspr(SPR_LPCR) & ~LPCR_HDICE);
+
+ report(got_interrupt, "interrupt on hdecrementer underflow");
+ got_interrupt = false;
+
+ handle_exception(0x980, NULL, NULL);
+
+done:
+ report_prefix_pop();
+}
+
+
+static volatile uint64_t recorded_heir;
+
+static void heai_handler(struct pt_regs *regs, void *data)
+{
+ got_interrupt = true;
+ memcpy((void *)&recorded_regs, regs, sizeof(struct pt_regs));
+ regs_advance_insn(regs);
+ if (cpu_has_heai)
+ recorded_heir = mfspr(SPR_HEIR);
+}
+
+static void program_handler(struct pt_regs *regs, void *data)
+{
+ got_interrupt = true;
+ memcpy((void *)&recorded_regs, regs, sizeof(struct pt_regs));
+ regs_advance_insn(regs);
+}
+
+/*
+ * This tests invalid instruction handling. powernv (HV) should take an
+ * HEAI interrupt with the HEIR SPR set to the instruction image. pseries
+ * (guest) should take a program interrupt. CPUs which support prefix
+ * should report prefix instruction in (H)SRR1[34].
+ */
+static void test_illegal(void)
+{
+ report_prefix_push("illegal instruction");
+
+ if (machine_is_powernv()) {
+ handle_exception(0xe40, &heai_handler, NULL);
+ } else {
+ handle_exception(0x700, &program_handler, NULL);
+ }
+
+ asm volatile(".long 0x12345678" ::: "memory");
+ report(got_interrupt, "interrupt on invalid instruction");
+ got_interrupt = false;
+ if (cpu_has_heai)
+ report(recorded_heir == 0x12345678, "HEIR: 0x%08lx", recorded_heir);
+ report(!regs_is_prefix(&recorded_regs), "(H)SRR1 prefix bit clear");
+
+ if (cpu_has_prefix) {
+ asm volatile(".balign 8 ; .long 0x04000123; .long 0x00badc0d");
+ report(got_interrupt, "interrupt on invalid prefix instruction");
+ got_interrupt = false;
+ if (cpu_has_heai)
+ report(recorded_heir == 0x0400012300badc0d, "HEIR: 0x%08lx", recorded_heir);
+ report(regs_is_prefix(&recorded_regs), "(H)SRR1 prefix bit set");
+ }
+
+ handle_exception(0xe40, NULL, NULL);
+ handle_exception(0x700, NULL, NULL);
+
+ report_prefix_pop();
+}
+
+static void sc_handler(struct pt_regs *regs, void *data)
+{
+ got_interrupt = true;
+ memcpy((void *)&recorded_regs, regs, sizeof(struct pt_regs));
+}
+
+static void test_sc(void)
+{
+ report_prefix_push("syscall");
+
+ handle_exception(0xc00, &sc_handler, NULL);
+
+ asm volatile("sc 0" ::: "memory");
+
+ report(got_interrupt, "interrupt on sc 0 instruction");
+ got_interrupt = false;
+ if (cpu_has_sc_lev)
+ report(((recorded_regs.msr >> 20) & 0x3) == 0, "SRR1 set LEV=0");
+ if (machine_is_powernv()) {
+ asm volatile("sc 1" ::: "memory");
+
+ report(got_interrupt, "interrupt on sc 1 instruction");
+ got_interrupt = false;
+ if (cpu_has_sc_lev)
+ report(((recorded_regs.msr >> 20) & 0x3) == 1, "SRR1 set LEV=1");
+ }
+
+ handle_exception(0xc00, NULL, NULL);
+
+ report_prefix_pop();
+}
+
+
+static void trace_handler(struct pt_regs *regs, void *data)
+{
+ got_interrupt = true;
+ memcpy((void *)&recorded_regs, regs, sizeof(struct pt_regs));
+ regs->msr &= ~(MSR_SE | MSR_BE);
+}
+
+static void program_trace_handler(struct pt_regs *regs, void *data)
+{
+ regs->msr &= ~(MSR_SE | MSR_BE);
+ regs->nip += 4;
+}
+
+extern char trace_insn[];
+extern char trace_insn2[];
+extern char trace_insn3[];
+extern char trace_rfid[];
+
+static void test_trace(void)
+{
+ unsigned long msr;
+
+ report_prefix_push("trace");
+
+ handle_exception(0xd00, &trace_handler, NULL);
+
+ msr = mfmsr() | MSR_SE;
+ asm volatile(
+ " mtmsr %0 \n"
+ ".global trace_insn \n"
+ "trace_insn: \n"
+ " nop \n"
+ : : "r"(msr) : "memory");
+
+ report(got_interrupt, "interrupt on single step");
+ got_interrupt = false;
+ report(recorded_regs.nip == (unsigned long)trace_insn + 4,
+ "single step interrupt at the correct address");
+ if (cpu_has_siar)
+ report(mfspr(SPR_SIAR) == (unsigned long)trace_insn,
+ "single step recorded SIAR at the correct address");
+
+ msr = mfmsr() | MSR_SE;
+ asm volatile(
+ " mtmsr %0 \n"
+ ".global trace_insn2 \n"
+ "trace_insn2: \n"
+ " b 1f \n"
+ " nop \n"
+ "1: \n"
+ : : "r"(msr) : "memory");
+
+ report(got_interrupt, "interrupt on single step branch");
+ got_interrupt = false;
+ report(recorded_regs.nip == (unsigned long)trace_insn2 + 8,
+ "single step interrupt at the correct address");
+ if (cpu_has_siar)
+ report(mfspr(SPR_SIAR) == (unsigned long)trace_insn2,
+ "single step recorded SIAR at the correct address");
+
+ msr = mfmsr() | MSR_BE;
+ asm volatile(
+ " mtmsr %0 \n"
+ ".global trace_insn3 \n"
+ "trace_insn3: \n"
+ " nop \n"
+ " b 1f \n"
+ " nop \n"
+ "1: \n"
+ : : "r"(msr) : "memory");
+
+ report(got_interrupt, "interrupt on branch trace");
+ got_interrupt = false;
+ report(recorded_regs.nip == (unsigned long)trace_insn3 + 12,
+ "branch trace interrupt at the correct address");
+ if (cpu_has_siar)
+ report(mfspr(SPR_SIAR) == (unsigned long)trace_insn3 + 4,
+ "branch trace recorded SIAR at the correct address");
+
+ handle_exception(0x700, &program_trace_handler, NULL);
+ msr = mfmsr() | MSR_SE;
+ asm volatile(
+ " mtmsr %0 \n"
+ " trap \n"
+ : : "r"(msr) : "memory");
+
+ report(!got_interrupt, "no interrupt on single step trap");
+ got_interrupt = false;
+ handle_exception(0x700, NULL, NULL);
+
+ msr = mfmsr() | MSR_SE;
+ mtspr(SPR_SRR0, (unsigned long)trace_rfid);
+ mtspr(SPR_SRR1, mfmsr());
+ asm volatile(
+ " mtmsr %0 \n"
+ " rfid \n"
+ ".global trace_rfid \n"
+ "trace_rfid: \n"
+ : : "r"(msr) : "memory");
+
+ report(!got_interrupt, "no interrupt on single step rfid");
+ got_interrupt = false;
+ handle_exception(0xd00, NULL, NULL);
+
+ report_prefix_pop();
+}
+
+
+int main(int argc, char **argv)
+{
+ report_prefix_push("interrupts");
+
+ if (cpu_has_power_mce)
+ test_mce();
+ test_dseg();
+ test_illegal();
+ test_dec();
+ test_sc();
+ test_trace();
+
+ report_prefix_pop();
+
+ return report_summary();
+}
diff --git a/powerpc/unittests.cfg b/powerpc/unittests.cfg
index 3c3783ba6..9fdc86b66 100644
--- a/powerpc/unittests.cfg
+++ b/powerpc/unittests.cfg
@@ -71,6 +71,9 @@ groups = rtas
[emulator]
file = emulator.elf

+[interrupts]
+file = interrupts.elf
+
[h_cede_tm]
file = tm.elf
machine = pseries
--
2.43.0