Re: [kvm-unit-tests v3 12/13] powerpc: Support powernv machine with QEMU TCG

Cédric Le Goater
2023-03-27T16:12:41Z

On 3/27/23 14:45, Nicholas Piggin wrote:
> 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.
>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>

Reviewed-by: Cédric Le Goater <clg@kaod.org>

> ---
> Since v2:
> - Don't call opal_init() twice [Cedric review]
> - Added BMC device to machine (helps with power-off and getting through
> BIOS with fewer error messages).
> - Set machine to little-endian mode with OPAL call if built LE.
> - Poll OPAL after making power-off call so IPMI state machine runs and
> it actually powers off QEMU properly.
>
> 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 6299ff5..5eec9d3 100644
> --- a/lib/powerpc/asm/ppc_asm.h
> +++ b/lib/powerpc/asm/ppc_asm.h
> @@ -36,7 +36,12 @@
> #endif /* __BYTE_ORDER__ */
>
> /* 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 4ad6612..9b318c3 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 711cb1b..37e52f5 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 a381688..ab7bb84 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 d4f21ba..943bf14 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 411e013..58b67d1 100644
> --- a/lib/powerpc/processor.c
> +++ b/lib/powerpc/processor.c
> @@ -78,6 +78,16 @@ 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 1be4c03..dd758db 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 0000000..7b1299f
> --- /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 0000000..1833358
> --- /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 0000000..84ab97b
> --- /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 b0ed2b1..06a7cf6 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 = $(TEST_DIR)/spapr_vpa.elf
> diff --git a/powerpc/cstart64.S b/powerpc/cstart64.S
> index 0592e03..2c82cd9 100644
> --- a/powerpc/cstart64.S
> +++ b/powerpc/cstart64.S
> @@ -92,6 +92,13 @@ start:
> sync
> isync
>
> + /* powernv machine does not check broken_sc1 */
> + mfmsr r3
> + li r4,1
> + sldi r4,r4,MSR_HV_BIT
> + and. r3,r3,r4
> + bne 1f
> +
> /* patch sc1 if needed */
> bl hcall_have_broken_sc1
> cmpwi r3, 0
> diff --git a/powerpc/run b/powerpc/run
> index ee38e07..f4ddd39 100755
> --- a/powerpc/run
> +++ b/powerpc/run
> @@ -1,5 +1,14 @@
> #!/usr/bin/env bash
>
> +get_qemu_machine ()
> +{
> + if [ "$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"
>