Hi, Steve.
Any updates for this series?
On 2021/9/1 5:15, Steven Sistare wrote:
> On 8/24/2021 5:36 AM, Zheng Chuan wrote:
>> Hi, Steve.
>>
>> I think I have found the problem, it is because the rom_reset() during the
>> cpr_exec will write dtb into the mach-virt.ram which cause the memory
>> corruption.
>> Also I found in x86 the memoryregion of acpi also changed during rom_rest.
>> Maybe we should keep it consistent and skip the rom_reset() like migration
>> does.
>> Here is the patch drafted(Also fix the cpr state missing saving problem):
>
> Hi Chuan, thank-you very much for debugging the problem. rom_reset() is a
> great find.
> I also noticed and have a fix ready for the mode bug. I will add similar
> fixes to patch V7.
>
> - Steve
>
>> diff --git a/hw/core/loader.c b/hw/core/loader.c
>> index 5b34869a5417..1dcf0be1492f 100644
>> --- a/hw/core/loader.c
>> +++ b/hw/core/loader.c
>> @@ -50,6 +50,7 @@
>> #include "hw/hw.h"
>> #include "disas/disas.h"
>> #include "migration/vmstate.h"
>> +#include "migration/cpr.h"
>> #include "monitor/monitor.h"
>> #include "sysemu/reset.h"
>> #include "sysemu/sysemu.h"
>> @@ -1128,7 +1129,7 @@ static void rom_reset(void *unused)
>> * the data in during the next incoming migration in all cases.
>> Note
>> * that some of those RAMs can actually be modified by the guest.
>> */
>> - if (runstate_check(RUN_STATE_INMIGRATE)) {
>> + if (runstate_check(RUN_STATE_INMIGRATE) || cpr_is_active()) {
>> if (rom->data && rom->isrom) {
>> /*
>> * Free it so that a rom_reset after migration doesn't
>> diff --git a/include/migration/cpr.h b/include/migration/cpr.h
>> index e9b987f54319..0b7d7e9f6bf0 100644
>> --- a/include/migration/cpr.h
>> +++ b/include/migration/cpr.h
>> @@ -20,9 +20,11 @@ void cpr_save_fd(const char *name, int id, int fd);
>> void cpr_delete_fd(const char *name, int id);
>> int cpr_find_fd(const char *name, int id);
>> int cpr_walk_fd(cpr_walk_fd_cb cb, void *handle);
>> -int cpr_state_save(Error **errp);
>> +int cpr_state_save(CprMode mode, Error **errp);
>> int cpr_state_load(Error **errp);
>> CprMode cpr_state_mode(void);
>> +void cpr_state_clear(void);
>> +bool cpr_is_active(void);
>> void cpr_state_print(void);
>>
>> int cpr_vfio_save(Error **errp);
>> diff --git a/migration/cpr-state.c b/migration/cpr-state.c
>> index 003b449bbcf8..4ac08539d932 100644
>> --- a/migration/cpr-state.c
>> +++ b/migration/cpr-state.c
>> @@ -19,7 +19,7 @@ typedef struct CprState {
>> CprNameList fds; /* list of CprFd */
>> } CprState;
>>
>> -static CprState cpr_state;
>> +static CprState cpr_state = { .mode = CPR_MODE_NONE };
>>
>> /*************************************************************************/
>> /* Generic list of names. */
>> @@ -149,7 +149,7 @@ static const VMStateDescription vmstate_cpr_state = {
>> }
>> };
>>
>> -int cpr_state_save(Error **errp)
>> +int cpr_state_save(CprMode mode, Error **errp)
>> {
>> int ret, mfd;
>> QEMUFile *f;
>> @@ -163,9 +163,11 @@ int cpr_state_save(Error **errp)
>> qemu_clear_cloexec(mfd);
>> f = qemu_fd_open(mfd, true, CPR_STATE_NAME);
>>
>> + cpr_state.mode = mode;
>> ret = vmstate_save_state(f, &vmstate_cpr_state, &cpr_state, 0);
>> if (ret) {
>> error_setg(errp, "vmstate_save_state error %d", ret);
>> + cpr_state.mode = CPR_MODE_NONE;
>> return ret;
>> }
>>
>> @@ -205,6 +207,16 @@ CprMode cpr_state_mode(void)
>> return cpr_state.mode;
>> }
>>
>> +void cpr_state_clear(void)
>> +{
>> + cpr_state.mode = CPR_MODE_NONE;
>> +}
>> +
>> +bool cpr_is_active(void)
>> +{
>> + return cpr_state.mode != CPR_MODE_NONE;
>> +}
>> +
>> void cpr_state_print(void)
>> {
>> CprName *elem;
>> diff --git a/migration/cpr.c b/migration/cpr.c
>> index d14bc5ad2678..97b2293c01e8 100644
>> --- a/migration/cpr.c
>> +++ b/migration/cpr.c
>> @@ -115,7 +115,7 @@ void qmp_cpr_exec(strList *args, Error **errp)
>> return;
>> }
>> cpr_walk_fd(preserve_fd, 0);
>> - if (cpr_state_save(errp)) {
>> + if (cpr_state_save(cpr_active_mode, errp)) {
>> return;
>> }
>> vhost_dev_reset_all();
>> @@ -173,4 +173,5 @@ void qmp_cpr_load(const char *filename, Error **errp)
>>
>> out:
>> cpr_active_mode = CPR_MODE_NONE;
>> + cpr_state_clear();
>> }
>>
>>
>> On 2021/8/24 5:36, Steven Sistare wrote:
>>> Hi Zheng, testing aarch64 is on our todo list. We will run this case and
>>> try to
>>> reproduce the failure. Thanks for the report.
>>>
>>> - Steve
>>>
>>> On 8/21/2021 4:54 AM, Zheng Chuan wrote:
>>>> Hi, steve
>>>>
>>>> It seems the VM will stuck after cpr-load on AArch64 environment？
>>>>
>>>> My AArch64 environment and test steps:
>>>> 1. linux kernel: 5.14-rc6
>>>> 2. QEMU version: v6.1.0-rc2 (patch your patchset), and configure with
>>>> `../configure --target-list=aarch64-softmmu --disable-werror --enable-kvm`
>>>> 4. Steps to live update:
>>>> # ./build/aarch64-softmmu/qemu-system-aarch64 -machine
>>>> virt,accel=kvm,gic-version=3,memfd-alloc=on -nodefaults -cpu host -m 2G
>>>> -smp 1 -drive
>>>> file=/usr/share/edk2/aarch64/QEMU_EFI-pflash.raw,if=pflash,format=raw,readonly=on
>>>> -drive file=<path/to/vm.qcow2>,format=qcow2,if=none,id=drive_image1
>>>> -device virtio-blk-pci,id=image1,drive=drive_image1 -vnc :10 -device
>>>> virtio-gpu,id=video0 -device piix3-usb-uhci,id=usb -device
>>>> usb-tablet,id=input0,bus=usb.0,port=1 -device
>>>> usb-kbd,id=input1,bus=usb.0,port=2 -monitor stdio
>>>> (qemu) cpr-save /tmp/qemu.save restart
>>>> (qemu) cpr-exec ./build/aarch64-softmmu/qemu-system-aarch64 -machine
>>>> virt,accel=kvm,gic-version=3,memfd-alloc=on -nodefaults -cpu host -m 2G
>>>> -smp 1 -drive
>>>> file=/usr/share/edk2/aarch64/QEMU_EFI-pflash.raw,if=pflash,format=raw,readonly=on
>>>> -drive file=<path/to/vm.qcow2>,format=qcow2,if=none,id=drive_image1
>>>> -device virtio-blk-pci,id=image1,drive=drive_image1 -vnc :10 -device
>>>> virtio-gpu,id=video0 -device piix3-usb-uhci,id=usb -device
>>>> usb-tablet,id=input0,bus=usb.0,port=1 -device
>>>> usb-kbd,id=input1,bus=usb.0,port=2 -monitor stdio -S
>>>> (qemu) QEMU 6.0.92 monitor - type 'help' for more information
>>>> (qemu) cpr-load /tmp/qemu.save
>>>>
>>>> Does I miss something?
>>>>
>>>> On 2021/8/7 5:43, Steve Sistare wrote:
>>>>> Provide the cpr-save, cpr-exec, and cpr-load commands for live update.
>>>>> These save and restore VM state, with minimal guest pause time, so that
>>>>> qemu may be updated to a new version in between.
>>>>>
>>>>> cpr-save stops the VM and saves vmstate to an ordinary file. It supports
>>>>> any type of guest image and block device, but the caller must not modify
>>>>> guest block devices between cpr-save and cpr-load. It supports two modes:
>>>>> reboot and restart.
>>>>>
>>>>> In reboot mode, the caller invokes cpr-save and then terminates qemu.
>>>>> The caller may then update the host kernel and system software and reboot.
>>>>> The caller resumes the guest by running qemu with the same arguments as
>>>>> the
>>>>> original process and invoking cpr-load. To use this mode, guest ram must
>>>>> be
>>>>> mapped to a persistent shared memory file such as /dev/dax0.0, or /dev/shm
>>>>> PKRAM as proposed in
>>>>> https://lore.kernel.org/lkml/1617140178-8773-1-git-send-email-anthony.yzn...@oracle.com.
>>>>>
>>>>> The reboot mode supports vfio devices if the caller first suspends the
>>>>> guest, such as by issuing guest-suspend-ram to the qemu guest agent. The
>>>>> guest drivers' suspend methods flush outstanding requests and
>>>>> re-initialize
>>>>> the devices, and thus there is no device state to save and restore.
>>>>>
>>>>> Restart mode preserves the guest VM across a restart of the qemu process.
>>>>> After cpr-save, the caller passes qemu command-line arguments to cpr-exec,
>>>>> which directly exec's the new qemu binary. The arguments must include -S
>>>>> so new qemu starts in a paused state and waits for the cpr-load command.
>>>>> The restart mode supports vfio devices by preserving the vfio container,
>>>>> group, device, and event descriptors across the qemu re-exec, and by
>>>>> updating DMA mapping virtual addresses using VFIO_DMA_UNMAP_FLAG_VADDR and
>>>>> VFIO_DMA_MAP_FLAG_VADDR as defined in
>>>>> https://lore.kernel.org/kvm/1611939252-7240-1-git-send-email-steven.sist...@oracle.com/
>>>>> and integrated in Linux kernel 5.12.
>>>>>
>>>>> To use the restart mode, qemu must be started with the memfd-alloc option,
>>>>> which allocates guest ram using memfd_create. The memfd's are saved to
>>>>> the environment and kept open across exec, after which they are found from
>>>>> the environment and re-mmap'd. Hence guest ram is preserved in place,
>>>>> albeit with new virtual addresses in the qemu process.
>>>>>
>>>>> The caller resumes the guest by invoking cpr-load, which loads state from
>>>>> the file. If the VM was running at cpr-save time, then VM execution
>>>>> resumes.
>>>>> If the VM was suspended at cpr-save time (reboot mode), then the caller
>>>>> must
>>>>> issue a system_wakeup command to resume.
>>>>>
>>>>> The first patches add reboot mode:
>>>>> - memory: qemu_check_ram_volatile
>>>>> - migration: fix populate_vfio_info
>>>>> - migration: qemu file wrappers
>>>>> - migration: simplify savevm
>>>>> - vl: start on wakeup request
>>>>> - cpr: reboot mode
>>>>> - cpr: reboot HMP interfaces
>>>>>
>>>>> The next patches add restart mode:
>>>>> - memory: flat section iterator
>>>>> - oslib: qemu_clear_cloexec
>>>>> - machine: memfd-alloc option
>>>>> - qapi: list utility functions
>>>>> - vl: helper to request re-exec
>>>>> - cpr: preserve extra state
>>>>> - cpr: restart mode
>>>>> - cpr: restart HMP interfaces
>>>>> - hostmem-memfd: cpr for memory-backend-memfd
>>>>>
>>>>> The next patches add vfio support for restart mode:
>>>>> - pci: export functions for cpr
>>>>> - vfio-pci: refactor for cpr
>>>>> - vfio-pci: cpr part 1 (fd and dma)
>>>>> - vfio-pci: cpr part 2 (msi)
>>>>> - vfio-pci: cpr part 3 (intx)
>>>>>
>>>>> The next patches preserve various descriptor-based backend devices across
>>>>> cprexec:
>>>>> - vhost: reset vhost devices for cpr
>>>>> - chardev: cpr framework
>>>>> - chardev: cpr for simple devices
>>>>> - chardev: cpr for pty
>>>>> - chardev: cpr for sockets
>>>>> - cpr: only-cpr-capable option
>>>>>
>>>>> Here is an example of updating qemu from v4.2.0 to v4.2.1 using
>>>>> restart mode. The software update is performed while the guest is
>>>>> running to minimize downtime.
>>>>>
>>>>> window 1 | window 2
>>>>> |
>>>>> # qemu-system-x86_64 ... |
>>>>> QEMU 4.2.0 monitor - type 'help' ... |
>>>>> (qemu) info status |
>>>>> VM status: running |
>>>>> | # yum update qemu
>>>>> (qemu) cpr-save /tmp/qemu.sav restart |
>>>>> (qemu) cpr-exec qemu-system-x86_64 -S ... |
>>>>> QEMU 4.2.1 monitor - type 'help' ... |
>>>>> (qemu) info status |
>>>>> VM status: paused (prelaunch) |
>>>>> (qemu) cpr-load /tmp/qemu.sav |
>>>>> (qemu) info status |
>>>>> VM status: running |
>>>>>
>>>>>
>>>>> Here is an example of updating the host kernel using reboot mode.
>>>>>
>>>>> window 1 | window 2
>>>>> |
>>>>> # qemu-system-x86_64 ...mem-path=/dev/dax0.0 ...|
>>>>> QEMU 4.2.1 monitor - type 'help' ... |
>>>>> (qemu) info status |
>>>>> VM status: running |
>>>>> | # yum update kernel-uek
>>>>> (qemu) cpr-save /tmp/qemu.sav restart |
>>>>> (qemu) quit |
>>>>> |
>>>>> # systemctl kexec |
>>>>> kexec_core: Starting new kernel |
>>>>> ... |
>>>>> |
>>>>> # qemu-system-x86_64 -S mem-path=/dev/dax0.0 ...|
>>>>> QEMU 4.2.1 monitor - type 'help' ... |
>>>>> (qemu) info status |
>>>>> VM status: paused (prelaunch) |
>>>>> (qemu) cpr-load /tmp/qemu.sav |
>>>>> (qemu) info status |
>>>>> VM status: running |
>>>>>
>>>>> Changes from V1 to V2:
>>>>> - revert vmstate infrastructure changes
>>>>> - refactor cpr functions into new files
>>>>> - delete MADV_DOEXEC and use memfd + VFIO_DMA_UNMAP_FLAG_SUSPEND to
>>>>> preserve memory.
>>>>> - add framework to filter chardev's that support cpr
>>>>> - save and restore vfio eventfd's
>>>>> - modify cprinfo QMP interface
>>>>> - incorporate misc review feedback
>>>>> - remove unrelated and unneeded patches
>>>>> - refactor all patches into a shorter and easier to review series
>>>>>
>>>>> Changes from V2 to V3:
>>>>> - rebase to qemu 6.0.0
>>>>> - use final definition of vfio ioctls (VFIO_DMA_UNMAP_FLAG_VADDR etc)
>>>>> - change memfd-alloc to a machine option
>>>>> - Use qio_channel_socket_new_fd instead of adding
>>>>> qio_channel_socket_new_fd
>>>>> - close monitor socket during cpr
>>>>> - fix a few unreported bugs
>>>>> - support memory-backend-memfd
>>>>>
>>>>> Changes from V3 to V4:
>>>>> - split reboot mode into separate patches
>>>>> - add cprexec command
>>>>> - delete QEMU_START_FREEZE, argv_main, and /usr/bin/qemu-exec
>>>>> - add more checks for vfio and cpr compatibility, and recover after
>>>>> errors
>>>>> - save vfio pci config in vmstate
>>>>> - rename {setenv,getenv}_event_fd to {save,load}_event_fd
>>>>> - use qemu_strtol
>>>>> - change 6.0 references to 6.1
>>>>> - use strerror(), use EXIT_FAILURE, remove period from error messages
>>>>> - distribute MAINTAINERS additions to each patch
>>>>>
>>>>> Changes from V4 to V5:
>>>>> - rebase to master
>>>>>
>>>>> Changes from V5 to V6:
>>>>> vfio:
>>>>> - delete redundant bus_master_enable_region in vfio_pci_post_load
>>>>> - delete unmap.size warning
>>>>> - fix phys_config memory leak
>>>>> - add INTX support
>>>>> - add vfio_named_notifier_init() helper
>>>>> Other:
>>>>> - 6.1 -> 6.2
>>>>> - rename file -> filename in qapi
>>>>> - delete cprinfo. qapi introspection serves the same purpose.
>>>>> - rename cprsave, cprexec, cprload -> cpr-save, cpr-exec, cpr-load
>>>>> - improve documentation in qapi/cpr.json
>>>>> - rename qemu_ram_volatile -> qemu_ram_check_volatile, and use
>>>>> qemu_ram_foreach_block
>>>>> - rename handle -> opaque
>>>>> - use ERRP_GUARD
>>>>> - use g_autoptr and g_autofree, and glib allocation functions
>>>>> - conform to error conventions for bool and int function return values
>>>>> and function names.
>>>>> - remove word "error" in error messages
>>>>> - rename as_flat_walk and its callback, and add comments.
>>>>> - rename qemu_clr_cloexec -> qemu_clear_cloexec
>>>>> - rename close-on-cpr -> reopen-on-cpr
>>>>> - add strList utility functions
>>>>> - factor out start on wakeup request to a separate patch
>>>>> - deleted unnecessary layer (cprsave etc) and squashed QMP patches
>>>>> - conditionally compile for CONFIG_VFIO
>>>>>
>>>>> Steve Sistare (24):
>>>>> memory: qemu_check_ram_volatile
>>>>> migration: fix populate_vfio_info
>>>>> migration: qemu file wrappers
>>>>> migration: simplify savevm
>>>>> vl: start on wakeup request
>>>>> cpr: reboot mode
>>>>> memory: flat section iterator
>>>>> oslib: qemu_clear_cloexec
>>>>> machine: memfd-alloc option
>>>>> qapi: list utility functions
>>>>> vl: helper to request re-exec
>>>>> cpr: preserve extra state
>>>>> cpr: restart mode
>>>>> cpr: restart HMP interfaces
>>>>> hostmem-memfd: cpr for memory-backend-memfd
>>>>> pci: export functions for cpr
>>>>> vfio-pci: refactor for cpr
>>>>> vfio-pci: cpr part 1 (fd and dma)
>>>>> vfio-pci: cpr part 2 (msi)
>>>>> vfio-pci: cpr part 3 (intx)
>>>>> chardev: cpr framework
>>>>> chardev: cpr for simple devices
>>>>> chardev: cpr for pty
>>>>> cpr: only-cpr-capable option
>>>>>
>>>>> Mark Kanda, Steve Sistare (3):
>>>>> cpr: reboot HMP interfaces
>>>>> vhost: reset vhost devices for cpr
>>>>> chardev: cpr for sockets
>>>>>
>>>>> MAINTAINERS | 12 ++
>>>>> backends/hostmem-memfd.c | 21 +--
>>>>> chardev/char-mux.c | 1 +
>>>>> chardev/char-null.c | 1 +
>>>>> chardev/char-pty.c | 14 +-
>>>>> chardev/char-serial.c | 1 +
>>>>> chardev/char-socket.c | 36 +++++
>>>>> chardev/char-stdio.c | 8 ++
>>>>> chardev/char.c | 43 +++++-
>>>>> gdbstub.c | 1 +
>>>>> hmp-commands.hx | 50 +++++++
>>>>> hw/core/machine.c | 19 +++
>>>>> hw/pci/msix.c | 20 ++-
>>>>> hw/pci/pci.c | 7 +-
>>>>> hw/vfio/common.c | 79 +++++++++--
>>>>> hw/vfio/cpr.c | 160 ++++++++++++++++++++++
>>>>> hw/vfio/meson.build | 1 +
>>>>> hw/vfio/pci.c | 301
>>>>> +++++++++++++++++++++++++++++++++++++++---
>>>>> hw/vfio/trace-events | 1 +
>>>>> hw/virtio/vhost.c | 11 ++
>>>>> include/chardev/char.h | 6 +
>>>>> include/exec/memory.h | 39 ++++++
>>>>> include/hw/boards.h | 1 +
>>>>> include/hw/pci/msix.h | 5 +
>>>>> include/hw/pci/pci.h | 2 +
>>>>> include/hw/vfio/vfio-common.h | 8 ++
>>>>> include/hw/virtio/vhost.h | 1 +
>>>>> include/migration/cpr.h | 31 +++++
>>>>> include/monitor/hmp.h | 3 +
>>>>> include/qapi/util.h | 28 ++++
>>>>> include/qemu/osdep.h | 1 +
>>>>> include/sysemu/runstate.h | 2 +
>>>>> include/sysemu/sysemu.h | 1 +
>>>>> linux-headers/linux/vfio.h | 6 +
>>>>> migration/cpr-state.c | 215 ++++++++++++++++++++++++++++++
>>>>> migration/cpr.c | 176 ++++++++++++++++++++++++
>>>>> migration/meson.build | 2 +
>>>>> migration/migration.c | 5 +
>>>>> migration/qemu-file-channel.c | 36 +++++
>>>>> migration/qemu-file-channel.h | 6 +
>>>>> migration/savevm.c | 21 +--
>>>>> migration/target.c | 24 +++-
>>>>> migration/trace-events | 5 +
>>>>> monitor/hmp-cmds.c | 68 ++++++----
>>>>> monitor/hmp.c | 3 +
>>>>> monitor/qmp.c | 3 +
>>>>> qapi/char.json | 7 +-
>>>>> qapi/cpr.json | 76 +++++++++++
>>>>> qapi/meson.build | 1 +
>>>>> qapi/qapi-schema.json | 1 +
>>>>> qapi/qapi-util.c | 37 ++++++
>>>>> qemu-options.hx | 40 +++++-
>>>>> softmmu/globals.c | 1 +
>>>>> softmmu/memory.c | 46 +++++++
>>>>> softmmu/physmem.c | 55 ++++++--
>>>>> softmmu/runstate.c | 38 +++++-
>>>>> softmmu/vl.c | 18 ++-
>>>>> stubs/cpr-state.c | 15 +++
>>>>> stubs/cpr.c | 3 +
>>>>> stubs/meson.build | 2 +
>>>>> trace-events | 1 +
>>>>> util/oslib-posix.c | 9 ++
>>>>> util/oslib-win32.c | 4 +
>>>>> util/qemu-config.c | 4 +
>>>>> 64 files changed, 1732 insertions(+), 111 deletions(-)
>>>>> create mode 100644 hw/vfio/cpr.c
>>>>> create mode 100644 include/migration/cpr.h
>>>>> create mode 100644 migration/cpr-state.c
>>>>> create mode 100644 migration/cpr.c
>>>>> create mode 100644 qapi/cpr.json
>>>>> create mode 100644 stubs/cpr-state.c
>>>>> create mode 100644 stubs/cpr.c
>>>>>
>>>>
>>> .
>>>
>>
> .
>
--
Regards.
Chuan
