Subject: [kvm-unit-tests v4 11/12] powerpc: Support powernv machine with QEMU TCG

From: Nicholas Piggin <[email-masked]>
Date: Thu, 8 Jun 2023 17:58:25 +1000

This is a basic first pass at powernv support using OPAL (skiboot)
firmware.

The ACCEL is a bit clunky, defaulting to kvm for powernv machine, which
isn't right and has to be manually overridden. It also does not yet run
in the run_tests.sh batch process, more work is needed to exclude
certain tests (e.g., rtas) and adjust parameters (e.g., increase memory
size) to allow powernv to work. For now it can run single test cases.

Reviewed-by: Cédric Le Goater <[email-masked]>
Signed-off-by: Nicholas Piggin <[email-masked]>
---
Since v3:
- Typo fix [Thomas]

 lib/powerpc/asm/ppc_asm.h   |  5 +++
 lib/powerpc/asm/processor.h | 10 +++++
 lib/powerpc/hcall.c         |  4 +-
 lib/powerpc/io.c            | 27 +++++++++++++-
 lib/powerpc/io.h            |  6 +++
 lib/powerpc/processor.c     | 10 +++++
 lib/powerpc/setup.c         |  8 ++--
 lib/ppc64/asm/opal.h        | 15 ++++++++
 lib/ppc64/opal-calls.S      | 46 +++++++++++++++++++++++
 lib/ppc64/opal.c            | 74 +++++++++++++++++++++++++++++++++++++
 powerpc/Makefile.ppc64      |  2 +
 powerpc/cstart64.S          |  7 ++++
 powerpc/run                 | 35 ++++++++++++++++--
 13 files changed, 238 insertions(+), 11 deletions(-)
 create mode 100644 lib/ppc64/asm/opal.h
 create mode 100644 lib/ppc64/opal-calls.S
 create mode 100644 lib/ppc64/opal.c

diff --git a/lib/powerpc/asm/ppc_asm.h b/lib/powerpc/asm/ppc_asm.h
index 46b4be00..63f11d13 100644
--- a/lib/powerpc/asm/ppc_asm.h
+++ b/lib/powerpc/asm/ppc_asm.h
@@ -39,7 +39,12 @@
 #define SPR_HSRR1	0x13B
 
 /* Machine State Register definitions: */
+#define MSR_LE_BIT	0
 #define MSR_EE_BIT	15			/* External Interrupts Enable */
+#define MSR_HV_BIT	60			/* Hypervisor mode */
 #define MSR_SF_BIT	63			/* 64-bit mode */
 
+#define SPR_HSRR0	0x13A
+#define SPR_HSRR1	0x13B
+
 #endif /* _ASMPOWERPC_PPC_ASM_H */
diff --git a/lib/powerpc/asm/processor.h b/lib/powerpc/asm/processor.h
index 4ad6612b..9b318c3e 100644
--- a/lib/powerpc/asm/processor.h
+++ b/lib/powerpc/asm/processor.h
@@ -3,6 +3,7 @@
 
 #include <libcflat.h>
 #include <asm/ptrace.h>
+#include <asm/ppc_asm.h>
 
 #ifndef __ASSEMBLY__
 void handle_exception(int trap, void (*func)(struct pt_regs *, void *), void *);
@@ -43,6 +44,15 @@ static inline void mtmsr(uint64_t msr)
 	asm volatile ("mtmsrd %[msr]" :: [msr] "r" (msr) : "memory");
 }
 
+/*
+ * This returns true on PowerNV / OPAL machines which run in hypervisor
+ * mode. False on pseries / PAPR machines that run in guest mode.
+ */
+static inline bool machine_is_powernv(void)
+{
+	return !!(mfmsr() & (1ULL << MSR_HV_BIT));
+}
+
 static inline uint64_t get_tb(void)
 {
 	return mfspr(SPR_TB);
diff --git a/lib/powerpc/hcall.c b/lib/powerpc/hcall.c
index 711cb1b0..37e52f54 100644
--- a/lib/powerpc/hcall.c
+++ b/lib/powerpc/hcall.c
@@ -25,7 +25,7 @@ int hcall_have_broken_sc1(void)
 	return r3 == (unsigned long)H_PRIVILEGE;
 }
 
-void putchar(int c)
+void papr_putchar(int c)
 {
 	unsigned long vty = 0;		/* 0 == default */
 	unsigned long nr_chars = 1;
@@ -34,7 +34,7 @@ void putchar(int c)
 	hcall(H_PUT_TERM_CHAR, vty, nr_chars, chars);
 }
 
-int __getchar(void)
+int __papr_getchar(void)
 {
 	register unsigned long r3 asm("r3") = H_GET_TERM_CHAR;
 	register unsigned long r4 asm("r4") = 0; /* 0 == default vty */
diff --git a/lib/powerpc/io.c b/lib/powerpc/io.c
index a381688b..ab7bb843 100644
--- a/lib/powerpc/io.c
+++ b/lib/powerpc/io.c
@@ -9,13 +9,33 @@
 #include <asm/spinlock.h>
 #include <asm/rtas.h>
 #include <asm/setup.h>
+#include <asm/processor.h>
 #include "io.h"
 
 static struct spinlock print_lock;
 
+void putchar(int c)
+{
+	if (machine_is_powernv())
+		opal_putchar(c);
+	else
+		papr_putchar(c);
+}
+
+int __getchar(void)
+{
+	if (machine_is_powernv())
+		return __opal_getchar();
+	else
+		return __papr_getchar();
+}
+
 void io_init(void)
 {
-	rtas_init();
+	if (machine_is_powernv())
+		assert(!opal_init());
+	else
+		rtas_init();
 }
 
 void puts(const char *s)
@@ -38,7 +58,10 @@ void exit(int code)
 // FIXME: change this print-exit/rtas-poweroff to chr_testdev_exit(),
 //        maybe by plugging chr-testdev into a spapr-vty.
 	printf("\nEXIT: STATUS=%d\n", ((code) << 1) | 1);
-	rtas_power_off();
+	if (machine_is_powernv())
+		opal_power_off();
+	else
+		rtas_power_off();
 	halt(code);
 	__builtin_unreachable();
 }
diff --git a/lib/powerpc/io.h b/lib/powerpc/io.h
index d4f21ba1..943bf142 100644
--- a/lib/powerpc/io.h
+++ b/lib/powerpc/io.h
@@ -8,6 +8,12 @@
 #define _POWERPC_IO_H_
 
 extern void io_init(void);
+extern int opal_init(void);
+extern void opal_power_off(void);
 extern void putchar(int c);
+extern void opal_putchar(int c);
+extern void papr_putchar(int c);
+extern int __opal_getchar(void);
+extern int __papr_getchar(void);
 
 #endif
diff --git a/lib/powerpc/processor.c b/lib/powerpc/processor.c
index 64d7ae01..58fea8cf 100644
--- a/lib/powerpc/processor.c
+++ b/lib/powerpc/processor.c
@@ -71,6 +71,16 @@ void sleep_tb(uint64_t cycles)
 {
 	uint64_t start, end, now;
 
+	if (machine_is_powernv()) {
+		/*
+		 * Could use 'stop' to sleep here which would be interesting.
+		 * stop with ESL=0 should be simple enough, ESL=1 would require
+		 * SRESET based wakeup which is more involved.
+		 */
+		delay(cycles);
+		return;
+	}
+
 	start = now = get_tb();
 	end = start + cycles;
 
diff --git a/lib/powerpc/setup.c b/lib/powerpc/setup.c
index 1be4c030..dd758db4 100644
--- a/lib/powerpc/setup.c
+++ b/lib/powerpc/setup.c
@@ -18,6 +18,7 @@
 #include <argv.h>
 #include <asm/setup.h>
 #include <asm/page.h>
+#include <asm/processor.h>
 #include <asm/hcall.h>
 #include "io.h"
 
@@ -97,12 +98,13 @@ static void cpu_init(void)
 	tb_hz = params.tb_hz;
 
 	/* Interrupt Endianness */
-
+	if (!machine_is_powernv()) {
 #if  __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
-        hcall(H_SET_MODE, 1, 4, 0, 0);
+		hcall(H_SET_MODE, 1, 4, 0, 0);
 #else
-        hcall(H_SET_MODE, 0, 4, 0, 0);
+		hcall(H_SET_MODE, 0, 4, 0, 0);
 #endif
+	}
 }
 
 static void mem_init(phys_addr_t freemem_start)
diff --git a/lib/ppc64/asm/opal.h b/lib/ppc64/asm/opal.h
new file mode 100644
index 00000000..7b1299f7
--- /dev/null
+++ b/lib/ppc64/asm/opal.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef _ASMPPC64_HCALL_H_
+#define _ASMPPC64_HCALL_H_
+
+#define OPAL_SUCCESS				0
+
+#define OPAL_CONSOLE_WRITE			1
+#define OPAL_CONSOLE_READ			2
+#define OPAL_CEC_POWER_DOWN			5
+#define OPAL_POLL_EVENTS			10
+#define OPAL_REINIT_CPUS			70
+# define OPAL_REINIT_CPUS_HILE_BE		(1 << 0)
+# define OPAL_REINIT_CPUS_HILE_LE		(1 << 1)
+
+#endif
diff --git a/lib/ppc64/opal-calls.S b/lib/ppc64/opal-calls.S
new file mode 100644
index 00000000..1833358c
--- /dev/null
+++ b/lib/ppc64/opal-calls.S
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (c) 2016 IBM Corporation.
+ */
+
+#include <asm/ppc_asm.h>
+
+	.text
+	.globl opal_call
+opal_call:
+	mr	r0,r3
+	mr	r3,r4
+	mr	r4,r5
+	mr	r5,r6
+	mr	r6,r7
+	mflr	r11
+	std	r11,16(r1)
+	mfcr	r12
+	stw	r12,8(r1)
+	mr	r13,r2
+
+	/* Set opal return address */
+	LOAD_REG_ADDR(r11, opal_return)
+	mtlr	r11
+	mfmsr	r12
+
+	/* switch to BE when we enter OPAL */
+	li	r11,(1 << MSR_LE_BIT)
+	andc	r12,r12,r11
+	mtspr	SPR_HSRR1,r12
+
+	/* load the opal call entry point and base */
+	LOAD_REG_ADDR(r11, opal)
+	ld	r12,8(r11)
+	ld	r2,0(r11)
+	mtspr	SPR_HSRR0,r12
+	hrfid
+
+opal_return:
+	FIXUP_ENDIAN
+	mr	r2,r13;
+	lwz	r11,8(r1);
+	ld	r12,16(r1)
+	mtcr	r11;
+	mtlr	r12
+	blr
diff --git a/lib/ppc64/opal.c b/lib/ppc64/opal.c
new file mode 100644
index 00000000..84ab97b8
--- /dev/null
+++ b/lib/ppc64/opal.c
@@ -0,0 +1,74 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * OPAL call helpers
+ */
+#include <asm/opal.h>
+#include <libcflat.h>
+#include <libfdt/libfdt.h>
+#include <devicetree.h>
+#include <asm/io.h>
+#include "../powerpc/io.h"
+
+struct opal {
+	uint64_t base;
+	uint64_t entry;
+} opal;
+
+extern int64_t opal_call(int64_t token, int64_t arg1, int64_t arg2, int64_t arg3);
+
+int opal_init(void)
+{
+	const struct fdt_property *prop;
+	int node, len;
+
+	node = fdt_path_offset(dt_fdt(), "/ibm,opal");
+	if (node < 0)
+		return -1;
+
+	prop = fdt_get_property(dt_fdt(), node, "opal-base-address", &len);
+	if (!prop)
+		return -1;
+	opal.base = fdt64_to_cpu(*(uint64_t *)prop->data);
+
+	prop = fdt_get_property(dt_fdt(), node, "opal-entry-address", &len);
+	if (!prop)
+		return -1;
+	opal.entry = fdt64_to_cpu(*(uint64_t *)prop->data);
+
+#if  __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+	if (opal_call(OPAL_REINIT_CPUS, OPAL_REINIT_CPUS_HILE_LE, 0, 0) != OPAL_SUCCESS)
+		return -1;
+#endif
+
+	return 0;
+}
+
+extern void opal_power_off(void)
+{
+	opal_call(OPAL_CEC_POWER_DOWN, 0, 0, 0);
+	while (true)
+		opal_call(OPAL_POLL_EVENTS, 0, 0, 0);
+}
+
+void opal_putchar(int c)
+{
+	unsigned long vty = 0;		/* 0 == default */
+	unsigned long nr_chars = cpu_to_be64(1);
+	char ch = c;
+
+	opal_call(OPAL_CONSOLE_WRITE, (int64_t)vty, (int64_t)&nr_chars, (int64_t)&ch);
+}
+
+int __opal_getchar(void)
+{
+	unsigned long vty = 0;		/* 0 == default */
+	unsigned long nr_chars = cpu_to_be64(1);
+	char ch;
+	int rc;
+
+	rc = opal_call(OPAL_CONSOLE_READ, (int64_t)vty, (int64_t)&nr_chars, (int64_t)&ch);
+	if (rc != OPAL_SUCCESS)
+		return -1;
+
+	return ch;
+}
diff --git a/powerpc/Makefile.ppc64 b/powerpc/Makefile.ppc64
index b0ed2b10..06a7cf67 100644
--- a/powerpc/Makefile.ppc64
+++ b/powerpc/Makefile.ppc64
@@ -17,6 +17,8 @@ cstart.o = $(TEST_DIR)/cstart64.o
 reloc.o  = $(TEST_DIR)/reloc64.o
 
 OBJDIRS += lib/ppc64
+cflatobjs += lib/ppc64/opal.o
+cflatobjs += lib/ppc64/opal-calls.o
 
 # ppc64 specific tests
 tests = $(TEST_DIR)/spapr_vpa.elf
diff --git a/powerpc/cstart64.S b/powerpc/cstart64.S
index e18ae9a2..185ebad5 100644
--- a/powerpc/cstart64.S
+++ b/powerpc/cstart64.S
@@ -92,6 +92,13 @@ start:
 	sync
 	isync
 
+	/* powernv machine does not check broken_sc1 */
+	mfmsr	r3
+	li	r4,1
+	sldi	r4,r4,MSR_HV_BIT
+	and.	r3,r3,r4
+	bne	1f
+
 	/* patch sc1 if needed */
 	bl	hcall_have_broken_sc1
 	cmpwi	r3, 0
diff --git a/powerpc/run b/powerpc/run
index ee38e075..f4ddd39c 100755
--- a/powerpc/run
+++ b/powerpc/run
@@ -1,5 +1,14 @@
 #!/usr/bin/env bash
 
+get_qemu_machine ()
+{
+	if [ "$MACHINE" ]; then
+		echo $MACHINE
+	else
+		echo pseries
+	fi
+}
+
 if [ -z "$KUT_STANDALONE" ]; then
 	if [ ! -f config.mak ]; then
 		echo "run ./configure && make first. See ./configure -h"
@@ -12,17 +21,35 @@ fi
 ACCEL=$(get_qemu_accelerator) ||
 	exit $?
 
+MACHINE=$(get_qemu_machine) ||
+	exit $?
+
+if [[ "$MACHINE" == "powernv"* ]] && [ "$ACCEL" = "kvm" ]; then
+	echo "PowerNV machine does not support KVM. ACCEL=tcg must be specified."
+	exit 2
+fi
+
 qemu=$(search_qemu_binary) ||
 	exit $?
 
-if ! $qemu -machine '?' 2>&1 | grep 'pseries' > /dev/null; then
-	echo "$qemu doesn't support pSeries ('-machine pseries'). Exiting."
+if ! $qemu -machine '?' 2>&1 | grep $MACHINE > /dev/null; then
+	echo "$qemu doesn't support '-machine $MACHINE'. Exiting."
 	exit 2
 fi
 
-M='-machine pseries'
+M="-machine $MACHINE"
 M+=",accel=$ACCEL"
-command="$qemu -nodefaults $M -bios $FIRMWARE"
+B=""
+if [[ "$MACHINE" == "pseries"* ]] ; then
+	B+="-bios $FIRMWARE"
+fi
+
+D=""
+if [[ "$MACHINE" == "powernv"* ]] ; then
+	D+="-device ipmi-bmc-sim,id=bmc0 -device isa-ipmi-bt,bmc=bmc0,irq=10"
+fi
+
+command="$qemu -nodefaults $M $B $D"
 command+=" -display none -serial stdio -kernel"
 command="$(migration_cmd) $(timeout_cmd) $command"
 
-- 
2.40.1