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Re: [Qemu-devel] [PATCH V4 3/3] tests: Add migration test for aarch64
From: |
Wei Huang |
Subject: |
Re: [Qemu-devel] [PATCH V4 3/3] tests: Add migration test for aarch64 |
Date: |
Mon, 26 Feb 2018 12:22:38 -0600 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 |
On 02/26/2018 03:03 AM, Andrew Jones wrote:
> On Fri, Feb 23, 2018 at 04:13:08PM -0600, Wei Huang wrote:
>>
>>
>> On 02/22/2018 03:00 AM, Andrew Jones wrote:
>>> On Wed, Feb 21, 2018 at 10:44:17PM -0600, Wei Huang wrote:
>>>> This patch adds migration test support for aarch64. The test code, which
>>>> implements the same functionality as x86, is booted as a kernel in qemu.
>>>> Here are the design choices we make for aarch64:
>>>>
>>>> * We choose this -kernel approach because aarch64 QEMU doesn't provide a
>>>> built-in fw like x86 does. So instead of relying on a boot loader, we
>>>> use -kernel approach for aarch64.
>>>> * The serial output is sent to PL011 directly.
>>>> * The physical memory base for mach-virt machine is 0x40000000. We change
>>>> the start_address and end_address for aarch64.
>>>>
>>>> In addition to providing the binary, this patch also includes the source
>>>> code and the build script in tests/migration/. So users can change the
>>>> source and/or re-compile the binary as they wish.
>>>>
>>>> Signed-off-by: Wei Huang <address@hidden>
>>>> ---
>>>> tests/Makefile.include | 1 +
>>>> tests/migration-test.c | 47 +++++++++++++++++++++---
>>>> tests/migration/Makefile | 12 +++++-
>>>> tests/migration/aarch64-a-b-kernel.S | 71
>>>> ++++++++++++++++++++++++++++++++++++
>>>> tests/migration/aarch64-a-b-kernel.h | 19 ++++++++++
>>>> tests/migration/migration-test.h | 5 +++
>>>> 6 files changed, 147 insertions(+), 8 deletions(-)
>>>> create mode 100644 tests/migration/aarch64-a-b-kernel.S
>>>> create mode 100644 tests/migration/aarch64-a-b-kernel.h
>>>>
>>>> diff --git a/tests/Makefile.include b/tests/Makefile.include
>>>> index a1bcbffe12..df9f64438f 100644
>>>> --- a/tests/Makefile.include
>>>> +++ b/tests/Makefile.include
>>>> @@ -372,6 +372,7 @@ check-qtest-arm-y += tests/sdhci-test$(EXESUF)
>>>> check-qtest-aarch64-y = tests/numa-test$(EXESUF)
>>>> check-qtest-aarch64-y += tests/sdhci-test$(EXESUF)
>>>> check-qtest-aarch64-y += tests/boot-serial-test$(EXESUF)
>>>> +check-qtest-aarch64-y += tests/migration-test$(EXESUF)
>>>>
>>>> check-qtest-microblazeel-y = $(check-qtest-microblaze-y)
>>>>
>>>> diff --git a/tests/migration-test.c b/tests/migration-test.c
>>>> index e2e06ed337..a4f6732a59 100644
>>>> --- a/tests/migration-test.c
>>>> +++ b/tests/migration-test.c
>>>> @@ -11,6 +11,7 @@
>>>> */
>>>>
>>>> #include "qemu/osdep.h"
>>>> +#include <sys/utsname.h>
>>>>
>>>> #include "libqtest.h"
>>>> #include "qapi/qmp/qdict.h"
>>>> @@ -23,8 +24,8 @@
>>>>
>>>> #include "migration/migration-test.h"
>>>>
>>>> -const unsigned start_address = TEST_MEM_START;
>>>> -const unsigned end_address = TEST_MEM_END;
>>>> +unsigned start_address = TEST_MEM_START;
>>>> +unsigned end_address = TEST_MEM_END;
>>>> bool got_stop;
>>>>
>>>> #if defined(__linux__)
>>>> @@ -81,12 +82,13 @@ static const char *tmpfs;
>>>> * outputting a 'B' every so often if it's still running.
>>>> */
>>>> #include "tests/migration/x86-a-b-bootblock.h"
>>>> +#include "tests/migration/aarch64-a-b-kernel.h"
>>>>
>>>> -static void init_bootfile_x86(const char *bootpath)
>>>> +static void init_bootfile(const char *bootpath, void *content)
>>>> {
>>>> FILE *bootfile = fopen(bootpath, "wb");
>>>>
>>>> - g_assert_cmpint(fwrite(x86_bootsect, 512, 1, bootfile), ==, 1);
>>>> + g_assert_cmpint(fwrite(content, 512, 1, bootfile), ==, 1);
>>>> fclose(bootfile);
>>>> }
>>>>
>>>> @@ -393,7 +395,7 @@ static void test_migrate_start(QTestState **from,
>>>> QTestState **to,
>>>> got_stop = false;
>>>>
>>>> if (strcmp(arch, "i386") == 0 || strcmp(arch, "x86_64") == 0) {
>>>> - init_bootfile_x86(bootpath);
>>>> + init_bootfile(bootpath, x86_bootsect);
>>>> cmd_src = g_strdup_printf("-machine accel=%s -m 150M"
>>>> " -name source,debug-threads=on"
>>>> " -serial file:%s/src_serial"
>>>> @@ -422,6 +424,39 @@ static void test_migrate_start(QTestState **from,
>>>> QTestState **to,
>>>> " -serial file:%s/dest_serial"
>>>> " -incoming %s",
>>>> accel, tmpfs, uri);
>>>> + } else if (strcmp(arch, "aarch64") == 0) {
>>>> + const char *cpu;
>>>> + const char *gic_ver;
>>>> + struct utsname utsname;
>>>> +
>>>> + /* kvm and tcg need different cpu and gic-version configs */
>>>> + if (access("/dev/kvm", F_OK) == 0 && uname(&utsname) == 0 &&
>>>> + strcmp(utsname.machine, "aarch64") == 0) {
>>>> + accel = "kvm";
>>>> + cpu = "host";
>>>> + gic_ver = "host";
>>>> + } else {
>>>> + accel = "tcg";
>>>> + cpu = "cortex-a57";
>>>> + gic_ver = "2";
>>>> + }
>>>> +
>>>> + init_bootfile(bootpath, aarch64_kernel);
>>>> + cmd_src = g_strdup_printf("-machine virt,accel=%s,gic-version=%s "
>>>> + "-name vmsource,debug-threads=on -cpu
>>>> %s "
>>>> + "-m 150M -serial file:%s/src_serial "
>>>> + "-kernel %s ",
>>>> + accel, gic_ver, cpu, tmpfs, bootpath);
>>>> + cmd_dst = g_strdup_printf("-machine virt,accel=%s,gic-version=%s "
>>>> + "-name vmdest,debug-threads=on -cpu %s "
>>>> + "-m 150M -serial file:%s/dest_serial "
>>>> + "-kernel %s "
>>>> + "-incoming %s ",
>>>> + accel, gic_ver, cpu, tmpfs, bootpath,
>>>> uri);
>>>> +
>>>> + /* aarch64 virt machine physical memory starts at 0x40000000 */
>>>> + start_address = ARM_TEST_MEM_START;
>>>> + end_address = ARM_TEST_MEM_END;
>>>> } else {
>>>> g_assert_not_reached();
>>>> }
>>>> @@ -506,7 +541,7 @@ static void test_deprecated(void)
>>>> {
>>>> QTestState *from;
>>>>
>>>> - from = qtest_start("");
>>>> + from = qtest_start("-machine none");
>>>>
>>>> deprecated_set_downtime(from, 0.12345);
>>>> deprecated_set_speed(from, "12345");
>>>> diff --git a/tests/migration/Makefile b/tests/migration/Makefile
>>>> index b768d0729d..b72d41367f 100644
>>>> --- a/tests/migration/Makefile
>>>> +++ b/tests/migration/Makefile
>>>> @@ -15,6 +15,7 @@ cross-gcc = $(firstword $(wildcard $(patsubst
>>>> %ld,%gcc,$(call cross-ld,$(1)))))
>>>> find-cross-prefix = $(subst gcc,,$(notdir $(call cross-gcc,$(1))))
>>>>
>>>> x86_64_cross_prefix := $(call find-cross-prefix,x86_64)
>>>> +aarch64_cross_prefix := $(call find-cross-prefix,aarch64)
>>>>
>>>> export __note
>>>> override define __note
>>>> @@ -25,7 +26,7 @@ override define __note
>>>> */
>>>> endef
>>>>
>>>> -all: x86-a-b-bootblock.h
>>>> +all: x86-a-b-bootblock.h aarch64-a-b-kernel.h
>>>>
>>>> x86-a-b-bootblock.h: x86-a-b-bootblock.S
>>>> $(x86_64_cross_prefix)gcc -m32 -march=i486 -c $< -o x86.o
>>>> @@ -34,5 +35,12 @@ x86-a-b-bootblock.h: x86-a-b-bootblock.S
>>>> echo "$$__note" > $@
>>>> xxd -i x86.bootsect | sed -e 's/.*int.*//' >> $@
>>>>
>>>> +aarch64-a-b-kernel.h: aarch64-a-b-kernel.S
>>>> + $(aarch64_cross_prefix)gcc -o aarch64.elf -nostdlib \
>>>> + -Wl,--build-id=none,-Ttext=40080000 $<
>>>
>>> Adding the arm64 Linux kernel offset here is a bit subtle. And, since the
>>> TEST_MEM_START is at 1M, that only leaves 512K for test code and data.
>>> I think you may want to define this offset somewhere, making it less
>>> subtle, and then also factor it in when computing the test mem start.
>>
>> I have fixed most parts based on your review comments, except for this
>> one. I think the section address, -Ttext=, doesn't matter in this case.
>> Such info is not present aarch64.kernel; plus QEMU loads the kernel into
>
> In this case it doesn't matter because your code only uses pc-relative
> addresses. It's pretty safe to assume the compiler will only emit pc-
> relative addresses for code like this, so that's probably fine.
>
>> the loader_start address, which is the physical memory base (0x40000000,
>> see virt.c). So the space to store kernel binary is 1MB, which should be
>> large enough to prevent aarch64-a-b-kernel.S from changing code.
>
> No, it loads the kernel at 0x40000000 + 0x80000, see
> hw/arm/boot.c:load_aarch64_image() and KERNEL64_LOAD_ADDR.
>
>>
>> Anyway I think we are fine to remove "-Ttext=40080000" here.
>
> Fine by me, but you might want to add a comment saying the code *must*
> only compile to using pc-relative addresses.
I think all ARM label-based branches are PC-relative (see
https://community.arm.com/processors/b/blog/posts/branch-and-call-sequences-explained).
So compilers aren't supposed to change this semantic. Anyway I just sent
a new version. It adds comments about compiler requirements.
>
> Thanks,
> drew
>
[Qemu-devel] [PATCH V4 1/3] tests/migration: Convert the boot block compilation script into Makefile, Wei Huang, 2018/02/21