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Re: [Qemu-devel] vhost-user:why region[0] always mmap failed ?
From: |
Linhaifeng |
Subject: |
Re: [Qemu-devel] vhost-user:why region[0] always mmap failed ? |
Date: |
Sat, 1 Nov 2014 10:28:21 +0800 |
User-agent: |
Mozilla/5.0 (Windows NT 6.1; rv:31.0) Gecko/20100101 Thunderbird/31.1.0 |
On 2014/10/16 5:28, Anshul Makkar wrote:
> Hi,
>
> Please can you share in what scenario this mapping fails. I am not seeing any
> such issue.
>
> Thanks
> Anshul Makkar
>
VM info:
memory:4G
hugepage size:2M
memory regions info:
gpa = 0xC0000
size = 3220439040
ua = 0x2aaaaacc0000
offset = 786432
gpa = 0x100000000
size = 1073741824
ua = 0x2aab6ac00000
offset = 18446650252267094016
gpa = 0x0
size = 655360
ua = 0x2aaaaac00000
offset = 0
log:
mmap fd[61] size[3221225472] failed
mmap fd[62] size[18446650253340835840] failed
> On Wed, Sep 17, 2014 at 10:33:23AM +0800, Linhaifeng wrote:
>> Hi,
>>
>> There is two memory regions when receive VHOST_SET_MEM_TABLE message:
>> region[0]
>> gpa = 0x0
>> size = 655360
>> ua = 0x2aaaaac00000
>> offset = 0
>> region[1]
>> gpa = 0xC0000
>> size = 2146697216
>> ua = 0x2aaaaacc0000
>> offset = 786432
>>
>> region[0] always mmap failed.The user code is :
>>
>> for (idx = 0; idx < msg->msg.memory.nregions; idx++) {
>> if (msg->fds[idx] > 0) {
>> size_t size;
>> uint64_t *guest_mem;
>> Region *region = &vhost_server->memory.regions[i];
>>
>> region->guest_phys_addr =
>> msg->msg.memory.regions[idx].guest_phys_addr;
>> region->memory_size = msg->msg.memory.regions[idx].memory_size;
>> region->userspace_addr =
>> msg->msg.memory.regions[idx].userspace_addr;
>> region->mmap_offset = msg->msg.memory.regions[idx].mmap_offset;
>>
>> assert(idx < msg->fd_num);
>> assert(msg->fds[idx] > 0);
>>
>> size = region->memory_size + region->mmap_offset;
>> guest_mem = mmap(0, size, PROT_READ | PROT_WRITE, MAP_SHARED,
>> msg->fds[idx], 0);
>> if (MAP_FAILED == guest_mem) {
>> continue;
>> }
>> i++;
>> guest_mem += (region->mmap_offset / sizeof(*guest_mem));
>> region->mmap_addr = (uint64_t)guest_mem;
>> vhost_server->memory.nregions++;
>> }
>> }
>>
>>
>
>
--
Regards,
Haifeng