Re: vhost-user technical isssues

[Linhaifeng <haifeng.lin-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>]

On 2014/11/14 11:40, Tetsuya Mukawa wrote:
> Hi Lin,
> 
> (2014/11/14 12:13), Linhaifeng wrote:
>>
>> size should be same as mmap and
>> guest_mem -= (memory.regions[i].mmap_offset / sizeof(*guest_mem));
>>
> 
> Thanks. It should be.
> How about following patch?
> 
> -------------------------------------------------------
> diff --git a/tests/vhost-user-test.c b/tests/vhost-user-test.c
> index 75fedf0..be4b171 100644
> --- a/tests/vhost-user-test.c
> +++ b/tests/vhost-user-test.c
> @@ -37,7 +37,7 @@
> #endif
> 
> #define QEMU_CMD_ACCEL " -machine accel=tcg"
> -#define QEMU_CMD_MEM " -m 512 -object
> memory-backend-file,id=mem,size=512M,"\
> +#define QEMU_CMD_MEM " -m 6000 -object
> memory-backend-file,id=mem,size=6000M,"\
> "mem-path=%s,share=on -numa node,memdev=mem"
> #define QEMU_CMD_CHR " -chardev socket,id=chr0,path=%s"
> #define QEMU_CMD_NETDEV " -netdev
> vhost-user,id=net0,chardev=chr0,vhostforce"
> @@ -221,13 +221,16 @@ static void read_guest_mem(void)
> 
> /* check for sanity */
> g_assert_cmpint(fds_num, >, 0);
> - g_assert_cmpint(fds_num, ==, memory.nregions);
> + //g_assert_cmpint(fds_num, ==, memory.nregions);
> 
> + fprintf(stderr, "%s(%d)\n", __func__, __LINE__);
> /* iterate all regions */
> for (i = 0; i < fds_num; i++) {
> + int ret = 0;
> 
> /* We'll check only the region statring at 0x0*/
> - if (memory.regions[i].guest_phys_addr != 0x0) {
> + if (memory.regions[i].guest_phys_addr == 0x0) {
> + close(fds[i]);
> continue;
> }
> 
> @@ -237,6 +240,7 @@ static void read_guest_mem(void)
> 
> guest_mem = mmap(0, size, PROT_READ | PROT_WRITE,


How many is size? mmap_size + mmap_offset ?


> MAP_SHARED, fds[i], 0);
> + fprintf(stderr, "region=%d, mmap=%p, size=%lu\n", i, guest_mem, size);
> 
> g_assert(guest_mem != MAP_FAILED);
> guest_mem += (memory.regions[i].mmap_offset / sizeof(*guest_mem));
> @@ -247,8 +251,10 @@ static void read_guest_mem(void)
> 
> g_assert_cmpint(a, ==, b);
> }
> -
> - munmap(guest_mem, memory.regions[i].memory_size);
> + guest_mem -= (memory.regions[i].mmap_offset / sizeof(*guest_mem));
> + ret = munmap(guest_mem, memory.regions[i].memory_size);

memory.regions[i].memory_size --> memory.regions[i].memory_size + memory.regions[i].memory_offset

check you have apply qemu's patch: [PATCH] vhost-user: fix mmap offset calculation

> + fprintf(stderr, "region=%d, munmap=%p, size=%lu, ret=%d\n",
> + i, guest_mem, size, ret);
> }
> 
> g_assert_cmpint(1, ==, 1);
> -------------------------------------------------------
> I am using 1GB hugepage size.
> 
> $ sudo QTEST_HUGETLBFS_PATH=/mnt/huge make check
> region=0, mmap=0x2aaac0000000, size=6291456000
> region=0, munmap=0x2aaac0000000, size=6291456000, ret=-1 << failed
> 
> 6291456000 is not aligned by 1GB.
> When I specify 4096MB as guest memory size, munmap() doesn't return
> error like following.
> 
> $ sudo QTEST_HUGETLBFS_PATH=/mnt/huge make check
> region=0, mmap=0x2aaac0000000, size=4294967296
> region=0, munmap=0x2aaac0000000, size=4294967296, ret=0
> 
> Thanks,
> Tetsuya
> 
> .
> 

-- 
Regards,
Haifeng