* Dr. David Alan Gilbert (dgilb...@redhat.com) wrote:
> * Wei Huang (w...@redhat.com) wrote:
> >
> >
> > On 09/28/2018 09:04 AM, Dr. David Alan Gilbert wrote:
> > > * Wei Huang (w...@redhat.com) wrote:
> > >>
> > >>
> > >> On 09/26/2018 11:31 AM, Dr. David Alan Gilbert wrote:
> > >>> * Wei Huang (w...@redhat.com) 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/aarch64. So users can
> > >>>> change
> > >>>> the source and/or re-compile the binary as they wish.
> > >>>>
> > >>>> Reviewed-by: Juan Quintela <quint...@redhat.com>
> > >>>> Signed-off-by: Wei Huang <w...@redhat.com>
> > >>>
> > >>> I've had to bounce this patch (kept the other 3) because the test
> > >>> is actually failing on aarch64 kvm.
> > >>> It's about 1 in 5 for me on one of the larger (40ish core) boxes which
> > >>> is otherwise idle.
> > >>>
> > >>> /aarch64/migration/precopy/unix: Memory content inconsistency at
> > >>> 43cf1000 first_byte = 5 last_byte = 4 current = 5 hit_edge = 1
> > >>> Memory content inconsistency at 43cf2000 first_byte = 5 last_byte = 4
> > >>> current = 5 hit_edge = 1
> > >>> Memory content inconsistency at 43cf3000 first_byte = 5 last_byte = 4
> > >>> current = 5 hit_edge = 1
> > >>> Memory content inconsistency at 43cf4000 first_byte = 5 last_byte = 4
> > >>> current = 5 hit_edge = 1
> > >>> Memory content inconsistency at 43cf5000 first_byte = 5 last_byte = 4
> > >>> current = 5 hit_edge = 1
> > >>> Memory content inconsistency at 43cf6000 first_byte = 5 last_byte = 4
> > >>> current = 5 hit_edge = 1
> > >>> Memory content inconsistency at 43cf7000 first_byte = 5 last_byte = 4
> > >>> current = 5 hit_edge = 1
> > >>
> > >> Thanks, Dave. The root cause is the wrong place of cache invalidation.
> > >> Here is the fix which has been tested on Amberwing. Could you please
> > >> verify it from your side? After that, I can either send in a new patch
> > >> or you can help me revise the existing one.
> > >
> > > Thanks, I'll grab a box and try it.
> > > If it works I'd prefer if you can resubmit the patch with the fix in.
> > >
> > > However, this fix looks suspicious to me. We check the guest ram
> > > contents after we stop the guest; if the guests RAM is inconsistent as
> > > seen by QEMU without the 'dc' then how will this work with normal
> > > applications?
> >
> > Such cases happened before. Here is the one presentation given at KVM
> > Forum:
> > https://events.static.linuxfound.org/sites/events/files/slides/slides_10.pdf.
>
> I have seen that presentation but I don't understand how it relates to
> your case. Imagine that we're migrating some totally arbitrary
> application - how do we know we get consistent memory - if you're
> having to put cache clears in the application that sounds like it's a
> real kvm/arm bug that needs fixing.
The change does seem to be working; but I really would like to
understand what's going on with the caches here.
Dave
> Dave
>
> > >
> > > Shouldn't this be something qemu or kvm is doing when it stops the
> > > guest?
> > >
> > > Dave
> > >
> > >> Thanks,
> > >> -Wei
> > >>
> > >>
> > >> diff --git a/tests/migration/aarch64/a-b-kernel.S
> > >> b/tests/migration/aarch64/a-b-
> > >> index 507af30..c8d2720 100644
> > >> --- a/tests/migration/aarch64/a-b-kernel.S
> > >> +++ b/tests/migration/aarch64/a-b-kernel.S
> > >> @@ -50,15 +50,15 @@ mainloop:
> > >> mov x4, x0
> > >>
> > >> innerloop:
> > >> - /* clean cache because el2 might still cache guest data under
> > >> KVM */
> > >> - dc civac, x4
> > >> -
> > >> /* increment the first byte of each page by 1 */
> > >> ldrb w3, [x4]
> > >> add w3, w3, #1
> > >> and w3, w3, #0xff
> > >> strb w3, [x4]
> > >>
> > >> + /* clean cache because el2 might still cache guest data under
> > >> KVM */
> > >> + dc civac, x4
> > >> +
> > >> add x4, x4, #TEST_MEM_PAGE_SIZE
> > >> cmp x4, x1
> > >> blt innerloop
> > >>
> > >>
> > >>>
> > >>> Dave
> > >>>
> > >>>> ---
> > >>>> tests/Makefile.include | 1 +
> > >>>> tests/migration-test.c | 27 +++++++++++--
> > >>>> tests/migration/Makefile | 2 +-
> > >>>> tests/migration/aarch64/Makefile | 20 ++++++++++
> > >>>> tests/migration/aarch64/a-b-kernel.S | 75
> > >>>> ++++++++++++++++++++++++++++++++++++
> > >>>> tests/migration/aarch64/a-b-kernel.h | 19 +++++++++
> > >>>> tests/migration/migration-test.h | 9 +++++
> > >>>> 7 files changed, 148 insertions(+), 5 deletions(-)
> > >>>> create mode 100644 tests/migration/aarch64/Makefile
> > >>>> 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 87c81d1..fab8fb9 100644
> > >>>> --- a/tests/Makefile.include
> > >>>> +++ b/tests/Makefile.include
> > >>>> @@ -390,6 +390,7 @@ check-qtest-arm-y += tests/hexloader-test$(EXESUF)
> > >>>> check-qtest-aarch64-y = tests/numa-test$(EXESUF)
> > >>>> check-qtest-aarch64-$(CONFIG_SDHCI) += tests/sdhci-test$(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 17c6896..ecfae0b 100644
> > >>>> --- a/tests/migration-test.c
> > >>>> +++ b/tests/migration-test.c
> > >>>> @@ -86,12 +86,13 @@ static const char *tmpfs;
> > >>>> * repeatedly. It outputs a 'B' at a fixed rate while it's still
> > >>>> running.
> > >>>> */
> > >>>> #include "tests/migration/i386/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);
> > >>>> }
> > >>>>
> > >>>> @@ -428,7 +429,7 @@ static int 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"
> > >>>> @@ -459,6 +460,24 @@ static int test_migrate_start(QTestState **from,
> > >>>> QTestState **to,
> > >>>>
> > >>>> start_address = PPC_TEST_MEM_START;
> > >>>> end_address = PPC_TEST_MEM_END;
> > >>>> + } else if (strcmp(arch, "aarch64") == 0) {
> > >>>> + init_bootfile(bootpath, aarch64_kernel);
> > >>>> + cmd_src = g_strdup_printf("-machine
> > >>>> virt,accel=%s,gic-version=max "
> > >>>> + "-name vmsource,debug-threads=on
> > >>>> -cpu max "
> > >>>> + "-m 150M -serial file:%s/src_serial
> > >>>> "
> > >>>> + "-kernel %s ",
> > >>>> + accel, tmpfs, bootpath);
> > >>>> + cmd_dst = g_strdup_printf("-machine
> > >>>> virt,accel=%s,gic-version=max "
> > >>>> + "-name vmdest,debug-threads=on -cpu
> > >>>> max "
> > >>>> + "-m 150M -serial
> > >>>> file:%s/dest_serial "
> > >>>> + "-kernel %s "
> > >>>> + "-incoming %s ",
> > >>>> + accel, tmpfs, bootpath, uri);
> > >>>> +
> > >>>> + start_address = ARM_TEST_MEM_START;
> > >>>> + end_address = ARM_TEST_MEM_END;
> > >>>> +
> > >>>> + g_assert(sizeof(aarch64_kernel) <= ARM_TEST_MAX_KERNEL_SIZE);
> > >>>> } else {
> > >>>> g_assert_not_reached();
> > >>>> }
> > >>>> @@ -545,7 +564,7 @@ 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 a9ed875..13af934 100644
> > >>>> --- a/tests/migration/Makefile
> > >>>> +++ b/tests/migration/Makefile
> > >>>> @@ -5,7 +5,7 @@
> > >>>> # See the COPYING file in the top-level directory.
> > >>>> #
> > >>>>
> > >>>> -TARGET_LIST = i386
> > >>>> +TARGET_LIST = i386 aarch64
> > >>>>
> > >>>> SRC_PATH = ../..
> > >>>>
> > >>>> diff --git a/tests/migration/aarch64/Makefile
> > >>>> b/tests/migration/aarch64/Makefile
> > >>>> new file mode 100644
> > >>>> index 0000000..d440fa8
> > >>>> --- /dev/null
> > >>>> +++ b/tests/migration/aarch64/Makefile
> > >>>> @@ -0,0 +1,20 @@
> > >>>> +# To specify cross compiler prefix, use CROSS_PREFIX=
> > >>>> +# $ make CROSS_PREFIX=aarch64-linux-gnu-
> > >>>> +
> > >>>> +.PHONY: all clean
> > >>>> +all: a-b-kernel.h
> > >>>> +
> > >>>> +a-b-kernel.h: aarch64.kernel
> > >>>> + echo "$$__note" > header.tmp
> > >>>> + xxd -i $< | sed -e 's/.*int.*//' >> header.tmp
> > >>>> + mv header.tmp $@
> > >>>> +
> > >>>> +aarch64.kernel: aarch64.elf
> > >>>> + $(CROSS_PREFIX)objcopy -O binary $< $@
> > >>>> +
> > >>>> +aarch64.elf: a-b-kernel.S
> > >>>> + $(CROSS_PREFIX)gcc -o $@ -nostdlib -Wl,--build-id=none $<
> > >>>> +
> > >>>> +clean:
> > >>>> + @rm -rf *.kernel *.elf
> > >>>> +
> > >>>> diff --git a/tests/migration/aarch64/a-b-kernel.S
> > >>>> b/tests/migration/aarch64/a-b-kernel.S
> > >>>> new file mode 100644
> > >>>> index 0000000..507af30
> > >>>> --- /dev/null
> > >>>> +++ b/tests/migration/aarch64/a-b-kernel.S
> > >>>> @@ -0,0 +1,75 @@
> > >>>> +#
> > >>>> +# Copyright (c) 2018 Red Hat, Inc. and/or its affiliates
> > >>>> +#
> > >>>> +# Author:
> > >>>> +# Wei Huang <w...@redhat.com>
> > >>>> +#
> > >>>> +# This work is licensed under the terms of the GNU GPL, version 2 or
> > >>>> later.
> > >>>> +# See the COPYING file in the top-level directory.
> > >>>> +#
> > >>>> +# Note: Please make sure the compiler compiles the assembly code
> > >>>> below with
> > >>>> +# pc-relative address. Also the branch instructions should use
> > >>>> relative
> > >>>> +# addresses only.
> > >>>> +
> > >>>> +#include "../migration-test.h"
> > >>>> +
> > >>>> +.section .text
> > >>>> +
> > >>>> + .globl _start
> > >>>> +
> > >>>> +_start:
> > >>>> + /* disable MMU to use phys mem address */
> > >>>> + mrs x0, sctlr_el1
> > >>>> + bic x0, x0, #(1<<0)
> > >>>> + msr sctlr_el1, x0
> > >>>> + isb
> > >>>> +
> > >>>> + /* traverse test memory region */
> > >>>> + mov x0, #ARM_TEST_MEM_START
> > >>>> + mov x1, #ARM_TEST_MEM_END
> > >>>> +
> > >>>> + /* output char 'A' to PL011 */
> > >>>> + mov w3, 'A'
> > >>>> + mov x2, #ARM_MACH_VIRT_UART
> > >>>> + strb w3, [x2]
> > >>>> +
> > >>>> + /* clean up memory */
> > >>>> + mov w3, #0
> > >>>> + mov x4, x0
> > >>>> +clean:
> > >>>> + strb w3, [x4]
> > >>>> + add x4, x4, #TEST_MEM_PAGE_SIZE
> > >>>> + cmp x4, x1
> > >>>> + ble clean
> > >>>> +
> > >>>> + /* w5 keeps a counter so we can limit the output speed */
> > >>>> + mov w5, #0
> > >>>> +
> > >>>> + /* main body */
> > >>>> +mainloop:
> > >>>> + mov x4, x0
> > >>>> +
> > >>>> +innerloop:
> > >>>> + /* clean cache because el2 might still cache guest data under
> > >>>> KVM */
> > >>>> + dc civac, x4
> > >>>> +
> > >>>> + /* increment the first byte of each page by 1 */
> > >>>> + ldrb w3, [x4]
> > >>>> + add w3, w3, #1
> > >>>> + and w3, w3, #0xff
> > >>>> + strb w3, [x4]
> > >>>> +
> > >>>> + add x4, x4, #TEST_MEM_PAGE_SIZE
> > >>>> + cmp x4, x1
> > >>>> + blt innerloop
> > >>>> +
> > >>>> + add w5, w5, #1
> > >>>> + and w5, w5, #0xff
> > >>>> + cmp w5, #0
> > >>>> + bne mainloop
> > >>>> +
> > >>>> + /* output char 'B' to PL011 */
> > >>>> + mov w3, 'B'
> > >>>> + strb w3, [x2]
> > >>>> +
> > >>>> + b mainloop
> > >>>> diff --git a/tests/migration/aarch64/a-b-kernel.h
> > >>>> b/tests/migration/aarch64/a-b-kernel.h
> > >>>> new file mode 100644
> > >>>> index 0000000..521125e
> > >>>> --- /dev/null
> > >>>> +++ b/tests/migration/aarch64/a-b-kernel.h
> > >>>> @@ -0,0 +1,19 @@
> > >>>> +/* This file is automatically generated from the assembly file in
> > >>>> + * tests/migration/aarch64. Edit that file and then run "make all"
> > >>>> + * inside tests/migration to update, and then remember to send both
> > >>>> + * the header and the assembler differences in your patch submission.
> > >>>> + */
> > >>>> +unsigned char aarch64_kernel[] = {
> > >>>> + 0x00, 0x10, 0x38, 0xd5, 0x00, 0xf8, 0x7f, 0x92, 0x00, 0x10, 0x18,
> > >>>> 0xd5,
> > >>>> + 0xdf, 0x3f, 0x03, 0xd5, 0x00, 0x02, 0xa8, 0xd2, 0x01, 0xc8, 0xa8,
> > >>>> 0xd2,
> > >>>> + 0x23, 0x08, 0x80, 0x52, 0x02, 0x20, 0xa1, 0xd2, 0x43, 0x00, 0x00,
> > >>>> 0x39,
> > >>>> + 0x03, 0x00, 0x80, 0x52, 0xe4, 0x03, 0x00, 0xaa, 0x83, 0x00, 0x00,
> > >>>> 0x39,
> > >>>> + 0x84, 0x04, 0x40, 0x91, 0x9f, 0x00, 0x01, 0xeb, 0xad, 0xff, 0xff,
> > >>>> 0x54,
> > >>>> + 0x05, 0x00, 0x80, 0x52, 0xe4, 0x03, 0x00, 0xaa, 0x24, 0x7e, 0x0b,
> > >>>> 0xd5,
> > >>>> + 0x83, 0x00, 0x40, 0x39, 0x63, 0x04, 0x00, 0x11, 0x63, 0x1c, 0x00,
> > >>>> 0x12,
> > >>>> + 0x83, 0x00, 0x00, 0x39, 0x84, 0x04, 0x40, 0x91, 0x9f, 0x00, 0x01,
> > >>>> 0xeb,
> > >>>> + 0x2b, 0xff, 0xff, 0x54, 0xa5, 0x04, 0x00, 0x11, 0xa5, 0x1c, 0x00,
> > >>>> 0x12,
> > >>>> + 0xbf, 0x00, 0x00, 0x71, 0x81, 0xfe, 0xff, 0x54, 0x43, 0x08, 0x80,
> > >>>> 0x52,
> > >>>> + 0x43, 0x00, 0x00, 0x39, 0xf1, 0xff, 0xff, 0x17
> > >>>> +};
> > >>>> +
> > >>>> diff --git a/tests/migration/migration-test.h
> > >>>> b/tests/migration/migration-test.h
> > >>>> index c4c0c52..6939a13 100644
> > >>>> --- a/tests/migration/migration-test.h
> > >>>> +++ b/tests/migration/migration-test.h
> > >>>> @@ -18,4 +18,13 @@
> > >>>> #define PPC_TEST_MEM_START (1 * 1024 * 1024)
> > >>>> #define PPC_TEST_MEM_END (100 * 1024 * 1024)
> > >>>>
> > >>>> +/* ARM */
> > >>>> +#define ARM_TEST_MEM_START (0x40000000 + 1 * 1024 * 1024)
> > >>>> +#define ARM_TEST_MEM_END (0x40000000 + 100 * 1024 * 1024)
> > >>>> +#define ARM_MACH_VIRT_UART 0x09000000
> > >>>> +/* AArch64 kernel load address is 0x40080000, and the test memory
> > >>>> starts at
> > >>>> + * 0x40100000. So the maximum allowable kernel size is 512KB.
> > >>>> + */
> > >>>> +#define ARM_TEST_MAX_KERNEL_SIZE (512 * 1024)
> > >>>> +
> > >>>> #endif /* _TEST_MIGRATION_H_ */
> > >>>> --
> > >>>> 1.8.3.1
> > >>>>
> > >>>>
> > >>> --
> > >>> Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
> > >>>
> > > --
> > > Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
> > >
> --
> Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
