executor/common_kvm_ppc64: fix KVM support

Turns out the ifuzz on powerpc did not ever properly work. This fixes
syz_kvm_setup_cpu$ppc64:

Enable the PAPR KVM capability (otherwise KVM_RUN fails right away).

Finish generated sequences with the software debug breakpoint as
there is no x86's "hlt" variant on POWER and otherwise KVM won't exit.

Add exception handlers, use the software debug breakpoint instruction
to trigger immediate exit from KVM with the only exception of
the decrementer interrupt handler (timer) to recharge the timer and
continue.

Define and use endianness selection flag (Big vs. Little endian).

Define the code generator similar to kvm_gen.cc which for now contains
2 simple tests and the decrementer interrupt handler code.

Add test cases to the executor so "bin/linux_ppc64le/syz-executor test"
can run some sensible tests. The tests copy 0xbadc0de around similar
to x86 and uses gpr[3] is a return value register (similar to EAX).

Signed-off-by: Alexey Kardashevskiy <aik@linux.ibm.com>

1 files changed, 27 insertions, 0 deletions

diff --git a/executor/test_linux.h b/executor/test_linux.h
index 69d647a4d..84efbdba0 100644
--- a/executor/test_linux.h
+++ b/executor/test_linux.h
@@ -84,6 +84,12 @@ static int test_one(int text_type, const char* text, int text_size, int flags, u
 		dump_cpu_state(cpufd, (char*)vm_mem);
 		return 1;
 	}
+#elif GOARCH_ppc64le
+	if (check_rax && regs.gpr[3] != 0xbadc0de) {
+		printf("wrong result: gps[3]=0x%llx\n", (long long)regs.gpr[3]);
+		dump_cpu_state(cpufd, (char*)vm_mem);
+		return 1;
+	}
 #endif
 	munmap(vm_mem, vm_mem_size);
 	munmap(cpu_mem, cpu_mem_size);
@@ -167,6 +173,15 @@ static int test_kvm()
 		if ((res = test_one(32, text_rsm, sizeof(text_rsm) - 1, KVM_SETUP_SMM, KVM_EXIT_HLT, false)))
 			return res;
 	}
+#elif GOARCH_ppc64le
+	for (unsigned i = 0; i < (1 << 1); ++i) {
+		res = test_one(8, kvm_ppc64_mr, sizeof(kvm_ppc64_mr) - 1, i, KVM_EXIT_DEBUG, true);
+		if (res)
+			return res;
+		res = test_one(8, kvm_ppc64_ld, sizeof(kvm_ppc64_ld) - 1, i, KVM_EXIT_DEBUG, true);
+		if (res)
+			return res;
+	}
 #else
 	// Keeping gcc happy
 	const char text8[] = "\x66\xb8\xde\xc0\xad\x0b";
@@ -234,5 +249,17 @@ static void dump_cpu_state(int cpufd, char* vm_mem)
 			       ((long long*)vm_mem)[i], ((long long*)vm_mem)[i + 1], ((long long*)vm_mem)[i + 2], ((long long*)vm_mem)[i + 3]);
 		}
 	}
+#elif GOARCH_ppc64 || GOARCH_ppc64le
+	printf("NIP %016lx\n", regs.pc);
+	printf("MSR %016lx\n", regs.msr);
+	printf("GPR00 %016lx %016lx %016lx %016lx\n", regs.gpr[0], regs.gpr[1], regs.gpr[2], regs.gpr[3]);
+	printf("GPR04 %016lx %016lx %016lx %016lx\n", regs.gpr[4], regs.gpr[5], regs.gpr[6], regs.gpr[7]);
+	printf("GPR08 %016lx %016lx %016lx %016lx\n", regs.gpr[8], regs.gpr[9], regs.gpr[10], regs.gpr[11]);
+	printf("GPR12 %016lx %016lx %016lx %016lx\n", regs.gpr[12], regs.gpr[13], regs.gpr[14], regs.gpr[15]);
+	printf("GPR16 %016lx %016lx %016lx %016lx\n", regs.gpr[16], regs.gpr[17], regs.gpr[18], regs.gpr[19]);
+	printf("GPR20 %016lx %016lx %016lx %016lx\n", regs.gpr[20], regs.gpr[21], regs.gpr[22], regs.gpr[23]);
+	printf("GPR24 %016lx %016lx %016lx %016lx\n", regs.gpr[24], regs.gpr[25], regs.gpr[26], regs.gpr[27]);
+	printf("GPR28 %016lx %016lx %016lx %016lx\n", regs.gpr[28], regs.gpr[29], regs.gpr[30], regs.gpr[31]);
+	printf(" SRR0 %016lx  SRR1 %016lx\n", regs.srr0, regs.srr1);
 #endif
 }