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Re: [Qemu-devel] scp during migration with vhost fails
From: |
Jason Wang |
Subject: |
Re: [Qemu-devel] scp during migration with vhost fails |
Date: |
Tue, 26 Feb 2013 17:52:10 +0800 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130106 Thunderbird/17.0.2 |
On 02/26/2013 04:44 PM, Michael S. Tsirkin wrote:
> On Tue, Feb 26, 2013 at 02:41:03PM +0800, Jason Wang wrote:
>> On 02/25/2013 06:01 PM, Michael S. Tsirkin wrote:
>>> On Mon, Feb 25, 2013 at 02:11:44PM +0800, Jason Wang wrote:
>>>> On 02/25/2013 01:57 PM, Jason Wang wrote:
>>>>> On 02/24/2013 05:54 AM, Michael S. Tsirkin wrote:
>>>>>> On Sat, Feb 23, 2013 at 10:49:29PM +0200, Michael S. Tsirkin wrote:
>>>>>>> On Fri, Feb 22, 2013 at 11:33:53PM +0800, Jason Wang wrote:
>>>>>>>> On 02/21/2013 07:23 PM, Michael S. Tsirkin wrote:
>>>>>>>>> On Thu, Feb 21, 2013 at 05:57:04PM +0800, Jason Wang wrote:
>>>>>>>>>> On 02/21/2013 12:48 AM, Michael S. Tsirkin wrote:
>>>>>>>>>>> On Wed, Feb 20, 2013 at 04:23:52PM +0200, Michael S. Tsirkin wrote:
>>>>>>>>>>>> On Fri, Feb 01, 2013 at 06:03:32PM +0800, Jason Wang wrote:
>>>>>>>>>>>>> Hello all:
>>>>>>>>>>>>>
>>>>>>>>>>>>> During testing, I find doing scp during migration with vhost
>>>>>>>>>>>>> fails with
>>>>>>>>>>>>> warnings in guest like:
>>>>>>>>>>>>>
>>>>>>>>>>>>> Corrupted MAC on input.
>>>>>>>>>>>>> Disconnecting: Packet corrupt.
>>>>>>>>>>>>> lost connection
>>>>>>>>>>>>>
>>>>>>>>>>>>> Here's the bisect result:
>>>>>>>>>>>>>
>>>>>>>>>>>>> Commit a01672d3968cf91208666d371784110bfde9d4f8 kvm: convert to
>>>>>>>>>>>>> MemoryListener
>>>>>>>>>>>>> API is the last commit that works well.
>>>>>>>>>>>>>
>>>>>>>>>>>>> With commit 04097f7c5957273c578f72b9bd603ba6b1d69e33 vhost:
>>>>>>>>>>>>> convert to
>>>>>>>>>>>>> MemoryListener API, guest network is unusable with warning of
>>>>>>>>>>>>> "bad gso type"
>>>>>>>>>>>>>
>>>>>>>>>>>>> With commit d743c382861eaa1e13f503b05aba5a382a7e7f7c vhost: fix
>>>>>>>>>>>>> incorrect
>>>>>>>>>>>>> userspace address, guest network is available, but scp during
>>>>>>>>>>>>> migration may
>>>>>>>>>>>>> fail.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Looks like the issue is related to memory api, any thoughts?
>>>>>>>>>>>>>
>>>>>>>>>>>>> Thanks
>>>>>>>>>>>> Tried to reproduce this for a while without success.
>>>>>>>>>>>> Which command line was used?
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> --
>>>>>>>>>>>> MST
>>>>>>>>>>> Could be we are not syncing all that we should?
>>>>>>>>>>> Does the following hack make the problem go away?
>>>>>>>>>>>
>>>>>>>>>>> diff --git a/hw/vhost.c b/hw/vhost.c
>>>>>>>>>>> index 8d41fdb..a7a0412 100644
>>>>>>>>>>> --- a/hw/vhost.c
>>>>>>>>>>> +++ b/hw/vhost.c
>>>>>>>>>>> @@ -69,6 +69,8 @@ static int vhost_sync_dirty_bitmap(struct
>>>>>>>>>>> vhost_dev *dev,
>>>>>>>>>>> hwaddr end_addr)
>>>>>>>>>>> {
>>>>>>>>>>> int i;
>>>>>>>>>>> + start_addr = 0x0;
>>>>>>>>>>> + end_addr = ~0x0ull;
>>>>>>>>>>>
>>>>>>>>>>> if (!dev->log_enabled || !dev->started) {
>>>>>>>>>>> return 0;
>>>>>>>>>>>
>>>>>>>>>> Still can reproduce with this. From the bisect result, the vhost
>>>>>>>>>> dirty
>>>>>>>>>> bitmap sync itself looks ok but something wrong when converting to
>>>>>>>>>> memory listener.
>>>>>>>>> Reading the code carefully, I found two bugs introduced during
>>>>>>>>> this conversion. Patch below, could you please try?
>>>>>>>>>
>>>>>>>>> vhost: memory sync fixes
>>>>>>>>>
>>>>>>>>> This fixes two bugs related to memory sync during
>>>>>>>>> migration:
>>>>>>>>> - ram address calculation was missing the chunk
>>>>>>>>> address, so the wrong page was dirtied
>>>>>>>>> - one after last was used instead of the
>>>>>>>>> end address of a region, which might overflow to 0
>>>>>>>>> and cause us to skip the region when the region ends at
>>>>>>>>> ~0x0ull.
>>>>>>>>>
>>>>>>>>> Signed-off-by: Michael S. Tsirkin <address@hidden>
>>>>>>>>>
>>>>>>>>> ---
>>>>>>>>>
>>>>>>>>> diff --git a/hw/vhost.c b/hw/vhost.c
>>>>>>>>> index 8d41fdb..dbf6b46 100644
>>>>>>>>> --- a/hw/vhost.c
>>>>>>>>> +++ b/hw/vhost.c
>>>>>>>>> @@ -55,7 +55,7 @@ static void vhost_dev_sync_region(struct vhost_dev
>>>>>>>>> *dev,
>>>>>>>>> ffsll(log) : ffs(log))) {
>>>>>>>>> ram_addr_t ram_addr;
>>>>>>>>> bit -= 1;
>>>>>>>>> - ram_addr = section->offset_within_region + bit *
>>>>>>>>> VHOST_LOG_PAGE;
>>>>>>>>> + ram_addr = section->offset_within_region + addr + bit *
>>>>>>>>> VHOST_LOG_PAGE;
>>>>>>>>> memory_region_set_dirty(section->mr, ram_addr,
>>>>>>>>> VHOST_LOG_PAGE);
>>>>>>>>> log &= ~(0x1ull << bit);
>>>>>>>>> }
>>>>>>>>> @@ -94,7 +94,7 @@ static void vhost_log_sync(MemoryListener *listener,
>>>>>>>>> struct vhost_dev *dev = container_of(listener, struct vhost_dev,
>>>>>>>>> memory_listener);
>>>>>>>>> hwaddr start_addr = section->offset_within_address_space;
>>>>>>>>> - hwaddr end_addr = start_addr + section->size;
>>>>>>>>> + hwaddr end_addr = start_addr + section->size - 1;
>>>>>>>>>
>>>>>>>>> vhost_sync_dirty_bitmap(dev, section, start_addr, end_addr);
>>>>>>>>> }
>>>>>>>>>
>>>>>>>> I can still reproduce the issue with this patch.
>>>>>>> Yes it's still wrong. We need the following on top.
>>>>>>> Could you try please?
>>>>>>>
>>>>>>> diff --git a/hw/vhost.c b/hw/vhost.c
>>>>>>> index dbf6b46..c324903 100644
>>>>>>> --- a/hw/vhost.c
>>>>>>> +++ b/hw/vhost.c
>>>>>>> @@ -29,7 +29,7 @@ static void vhost_dev_sync_region(struct vhost_dev
>>>>>>> *dev,
>>>>>>> uint64_t end = MIN(mlast, rlast);
>>>>>>> vhost_log_chunk_t *from = dev->log + start / VHOST_LOG_CHUNK;
>>>>>>> vhost_log_chunk_t *to = dev->log + end / VHOST_LOG_CHUNK + 1;
>>>>>>> - uint64_t addr = (start / VHOST_LOG_CHUNK) * VHOST_LOG_CHUNK;
>>>>>>> + uint64_t addr = 0;
>>>>>>>
>>>>>>> if (end < start) {
>>>>>>> return;
>>>>>> Sorry, scratch that last one, sorry.
>>>>>> This should be the right thing, I think: on top of
>>>>>> 'vhost: memory sync fixes'.
>>>>>>
>>>>>> diff --git a/hw/vhost.c b/hw/vhost.c
>>>>>> index dbf6b46..72c0095 100644
>>>>>> --- a/hw/vhost.c
>>>>>> +++ b/hw/vhost.c
>>>>>> @@ -53,9 +53,10 @@ static void vhost_dev_sync_region(struct vhost_dev
>>>>>> *dev,
>>>>>> log = __sync_fetch_and_and(from, 0);
>>>>>> while ((bit = sizeof(log) > sizeof(int) ?
>>>>>> ffsll(log) : ffs(log))) {
>>>>>> - ram_addr_t ram_addr;
>>>>>> + hwaddr ram_addr;
>>>>>> bit -= 1;
>>>>>> - ram_addr = section->offset_within_region + addr + bit *
>>>>>> VHOST_LOG_PAGE;
>>>>>> + ram_addr = addr + bit * VHOST_LOG_PAGE -
>>>>>> + section->mr->offset_within_address_space;
>>>>> should be section->offset_within_address_space
>>>>>> memory_region_set_dirty(section->mr, ram_addr,
>>>>>> VHOST_LOG_PAGE);
>>>>>> log &= ~(0x1ull << bit);
>>>>>> }
>>>>>>
>>>>>>
>>>>> Still can reproduce. An interesting thing is after I chage the
>>>>> section->offset_within_address_space to section->mr->ram_addr[1]. I
>>>>> can't reproduce the issue. I haven't read all the codes, but it looks
>>>>> like something is wrong with the valueof
>>>>> section->offset_within_address_space? Thanks
>>>> It's ok since we need offset inside the region as the second parameter
>>>> of memory_region_set_dirty().
>>>>> [1]
>>>>> diff --git a/hw/vhost.c b/hw/vhost.c
>>>>> index 8d41fdb..785e68e 100644
>>>>> --- a/hw/vhost.c
>>>>> +++ b/hw/vhost.c
>>>>> @@ -55,7 +55,7 @@ static void vhost_dev_sync_region(struct vhost_dev *dev,
>>>>> ffsll(log) : ffs(log))) {
>>>>> ram_addr_t ram_addr;
>>>>> bit -= 1;
>>>>> - ram_addr = section->offset_within_region + bit *
>>>>> VHOST_LOG_PAGE;
>>>>> + ram_addr = addr + bit * VHOST_LOG_PAGE -
>>>>> section->mr->ram_addr;
>>>>> memory_region_set_dirty(section->mr, ram_addr,
>>>>> VHOST_LOG_PAGE);
>>>>> log &= ~(0x1ull << bit);
>>>>> }
>>>>>
>>>>>
>>> OK I think now I get it.
>>> The following should be the real thing.
>>>
>>>
>>> diff --git a/hw/vhost.c b/hw/vhost.c
>>> index dbf6b46..2d8ead8 100644
>>> --- a/hw/vhost.c
>>> +++ b/hw/vhost.c
>>> @@ -53,10 +53,14 @@ static void vhost_dev_sync_region(struct vhost_dev *dev,
>>> log = __sync_fetch_and_and(from, 0);
>>> while ((bit = sizeof(log) > sizeof(int) ?
>>> ffsll(log) : ffs(log))) {
>>> - ram_addr_t ram_addr;
>>> + hwaddr page_addr;
>>> + hwaddr section_offset;
>>> + hwaddr mr_offset;
>>> bit -= 1;
>>> - ram_addr = section->offset_within_region + addr + bit *
>>> VHOST_LOG_PAGE;
>>> - memory_region_set_dirty(section->mr, ram_addr, VHOST_LOG_PAGE);
>>> + page_addr = addr + bit * VHOST_LOG_PAGE;
>>> + section_offset = ram_addr -
>>> section->offset_within_address_space;
>> Should be page_addr here.
>>> + mr_offset = section_offset + section->offset_within_region;
>>> + memory_region_set_dirty(section->mr, mr_offset,
>>> VHOST_LOG_PAGE);
>>> log &= ~(0x1ull << bit);
>>> }
>>> addr += VHOST_LOG_CHUNK;
>>>
>>>
>>>
>> I get segfault with this patch, and looks like we need to check whether
>> the regions are overlapped in the begining of vhost_dev_sync_region:
>>
>> if (!ranges_overlap(start, end - start + 1,
>> section->offset_within_address_space,
>> section->size)) {
>> return;
>> }
>>
>> With this, no segfault and I can not reproduce the issue again.
> OK, and I guess this works because sync sections ATM do not cross
> tracking sections, but it does not seem to be required by the API, so I
> think we really should be more careful and only sync the correct range.
>
> Signed-off-by: Michael S. Tsirkin <address@hidden>
The patch works well.
Thanks
> diff --git a/hw/vhost.c b/hw/vhost.c
> index dbf6b46..37777c2 100644
> --- a/hw/vhost.c
> +++ b/hw/vhost.c
> @@ -53,10 +53,14 @@ static void vhost_dev_sync_region(struct vhost_dev *dev,
> log = __sync_fetch_and_and(from, 0);
> while ((bit = sizeof(log) > sizeof(int) ?
> ffsll(log) : ffs(log))) {
> - ram_addr_t ram_addr;
> + hwaddr page_addr;
> + hwaddr section_offset;
> + hwaddr mr_offset;
> bit -= 1;
> - ram_addr = section->offset_within_region + addr + bit *
> VHOST_LOG_PAGE;
> - memory_region_set_dirty(section->mr, ram_addr, VHOST_LOG_PAGE);
> + page_addr = addr + bit * VHOST_LOG_PAGE;
> + section_offset = page_addr -
> section->offset_within_address_space;
> + mr_offset = section_offset + section->offset_within_region;
> + memory_region_set_dirty(section->mr, mr_offset, VHOST_LOG_PAGE);
> log &= ~(0x1ull << bit);
> }
> addr += VHOST_LOG_CHUNK;
> @@ -65,14 +69,21 @@ static void vhost_dev_sync_region(struct vhost_dev *dev,
>
> static int vhost_sync_dirty_bitmap(struct vhost_dev *dev,
> MemoryRegionSection *section,
> - hwaddr start_addr,
> - hwaddr end_addr)
> + hwaddr first,
> + hwaddr last)
> {
> int i;
> + hwaddr start_addr;
> + hwaddr end_addr;
>
> if (!dev->log_enabled || !dev->started) {
> return 0;
> }
> + start_addr = section->offset_within_address_space;
> + end_addr = range_get_last(start_addr, section->size);
> + start_addr = MAX(first, start_addr);
> + end_addr = MIN(last, end_addr);
> +
> for (i = 0; i < dev->mem->nregions; ++i) {
> struct vhost_memory_region *reg = dev->mem->regions + i;
> vhost_dev_sync_region(dev, section, start_addr, end_addr,
> @@ -93,10 +104,18 @@ static void vhost_log_sync(MemoryListener *listener,
> {
> struct vhost_dev *dev = container_of(listener, struct vhost_dev,
> memory_listener);
> - hwaddr start_addr = section->offset_within_address_space;
> - hwaddr end_addr = start_addr + section->size - 1;
> + vhost_sync_dirty_bitmap(dev, section, 0x0, ~0x0ULL);
> +}
>
> - vhost_sync_dirty_bitmap(dev, section, start_addr, end_addr);
> +static void vhost_log_sync_range(struct vhost_dev *dev,
> + hwaddr first, hwaddr last)
> +{
> + int i;
> + /* FIXME: this is N^2 in number of sections */
> + for (i = 0; i < dev->n_mem_sections; ++i) {
> + MemoryRegionSection *section = &dev->mem_sections[i];
> + vhost_sync_dirty_bitmap(dev, section, first, last);
> + }
> }
>
> /* Assign/unassign. Keep an unsorted array of non-overlapping
> @@ -268,16 +287,15 @@ static inline void vhost_dev_log_resize(struct
> vhost_dev* dev, uint64_t size)
> {
> vhost_log_chunk_t *log;
> uint64_t log_base;
> - int r, i;
> + int r;
>
> log = g_malloc0(size * sizeof *log);
> log_base = (uint64_t)(unsigned long)log;
> r = ioctl(dev->control, VHOST_SET_LOG_BASE, &log_base);
> assert(r >= 0);
> - for (i = 0; i < dev->n_mem_sections; ++i) {
> - /* Sync only the range covered by the old log */
> - vhost_sync_dirty_bitmap(dev, &dev->mem_sections[i], 0,
> - dev->log_size * VHOST_LOG_CHUNK - 1);
> + /* Sync only the range covered by the old log */
> + if (dev->log_size) {
> + vhost_log_sync_range(dev, 0, dev->log_size * VHOST_LOG_CHUNK - 1);
> }
> if (dev->log) {
> g_free(dev->log);
> @@ -1014,10 +1032,7 @@ void vhost_dev_stop(struct vhost_dev *hdev,
> VirtIODevice *vdev)
> hdev->vqs + i,
> hdev->vq_index + i);
> }
> - for (i = 0; i < hdev->n_mem_sections; ++i) {
> - vhost_sync_dirty_bitmap(hdev, &hdev->mem_sections[i],
> - 0, (hwaddr)~0x0ull);
> - }
> + vhost_log_sync_range(hdev, 0, ~0x0ull);
>
> hdev->started = false;
> g_free(hdev->log);
>
- Re: [Qemu-devel] scp during migration with vhost fails, (continued)
- Re: [Qemu-devel] scp during migration with vhost fails, Jason Wang, 2013/02/21
- Re: [Qemu-devel] scp during migration with vhost fails, Michael S. Tsirkin, 2013/02/21
- Re: [Qemu-devel] scp during migration with vhost fails, Jason Wang, 2013/02/22
- Re: [Qemu-devel] scp during migration with vhost fails, Michael S. Tsirkin, 2013/02/23
- Re: [Qemu-devel] scp during migration with vhost fails, Michael S. Tsirkin, 2013/02/23
- Re: [Qemu-devel] scp during migration with vhost fails, Jason Wang, 2013/02/25
- Re: [Qemu-devel] scp during migration with vhost fails, Jason Wang, 2013/02/25
- Re: [Qemu-devel] scp during migration with vhost fails, Michael S. Tsirkin, 2013/02/25
- Re: [Qemu-devel] scp during migration with vhost fails, Jason Wang, 2013/02/26
- Re: [Qemu-devel] scp during migration with vhost fails, Michael S. Tsirkin, 2013/02/26
- Re: [Qemu-devel] scp during migration with vhost fails,
Jason Wang <=
- Re: [Qemu-devel] scp during migration with vhost fails, Michael S. Tsirkin, 2013/02/25
Re: [Qemu-devel] scp during migration with vhost fails, Jason Wang, 2013/02/21