[PATCH] libxl: remove the xl list limit of 1024 domains

[PATCH] libxl: remove the xl list limit of 1024 domains

[Juergen Gross]

xl list is currently limited to 1024 domains. Remove the limit.

Signed-off-by: Juergen Gross <jgross@suse.com>
---
 tools/libxl/libxl.c | 37 ++++++++++++++++++-------------------
 1 file changed, 18 insertions(+), 19 deletions(-)

diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c
index 9207621..83e37a9 100644
--- a/tools/libxl/libxl.c
+++ b/tools/libxl/libxl.c
@@ -649,31 +649,30 @@ static void xcinfo2xlinfo(libxl_ctx *ctx,
 
 libxl_dominfo * libxl_list_domain(libxl_ctx *ctx, int *nb_domain_out)
 {
-    libxl_dominfo *ptr;
+    libxl_dominfo *ptr = NULL;
     int i, ret;
     xc_domaininfo_t info[1024];
-    int size = 1024;
+    int size = 0;
+    uint32_t domid = 0;
     GC_INIT(ctx);
 
-    ptr = calloc(size, sizeof(libxl_dominfo));
-    if (!ptr) {
-        LOGE(ERROR, "allocating domain info");
-        GC_FREE;
-        return NULL;
-    }
-
-    ret = xc_domain_getinfolist(ctx->xch, 0, 1024, info);
-    if (ret<0) {
-        LOGE(ERROR, "getting domain info list");
-        free(ptr);
-        GC_FREE;
-        return NULL;
+    for (ret = 1; ret;) {
+        ret = xc_domain_getinfolist(ctx->xch, domid, 1024, info);
+        if (ret < 0) {
+            LOGE(ERROR, "getting domain info list");
+            free(ptr);
+            GC_FREE;
+            return NULL;
+        }
+        ptr = libxl__realloc(NOGC, ptr, (size + ret) * sizeof(libxl_dominfo));
+        for (i = 0; i < ret; i++) {
+            xcinfo2xlinfo(ctx, &info[i], &ptr[size + i]);
+        }
+        domid = info[ret - 1].domain + 1;
+        size += ret;
     }
 
-    for (i = 0; i < ret; i++) {
-        xcinfo2xlinfo(ctx, &info[i], &ptr[i]);
-    }
-    *nb_domain_out = ret;
+    *nb_domain_out = size;
     GC_FREE;
     return ptr;
 }
-- 
2.6.2

Re: [PATCH] libxl: remove the xl list limit of 1024 domains

[Andrew Cooper]

On 18/12/15 14:34, Juergen Gross wrote:
> xl list is currently limited to 1024 domains. Remove the limit.
>
> Signed-off-by: Juergen Gross <jgross@suse.com>

libxl_list_vm() needs similar treatment.  In fact, it looks as if it
should be implemented in terms of libxl_list_domain(), rather than
opencoding similar same logic.

~Andrew

Re: [PATCH] libxl: remove the xl list limit of 1024 domains

[Juergen Gross]

On 18/12/15 15:47, Andrew Cooper wrote:
> On 18/12/15 14:34, Juergen Gross wrote:
>> xl list is currently limited to 1024 domains. Remove the limit.
>>
>> Signed-off-by: Juergen Gross <jgross@suse.com>
> 
> libxl_list_vm() needs similar treatment.  In fact, it looks as if it
> should be implemented in terms of libxl_list_domain(), rather than
> opencoding similar same logic.

Yeah, and get_domain_ids() in tools/xenstat/libxenstat/src/xenstat_qmp.c
has the same problem.

I won't be able to the patches today and I'll be back from holidays only
next year. I'll do the patches in case no one else is stepping up.


Juergen

Re: [PATCH] libxl: remove the xl list limit of 1024 domains

[Juergen Gross]

On 18/12/15 15:34, Juergen Gross wrote:
> xl list is currently limited to 1024 domains. Remove the limit.
> 
> Signed-off-by: Juergen Gross <jgross@suse.com>

Found a bug, will send V2 soon (together with two other patches
addressing a similar limitation in xl vm-list and tools/xenstat.


Juergen

> ---
>  tools/libxl/libxl.c | 37 ++++++++++++++++++-------------------
>  1 file changed, 18 insertions(+), 19 deletions(-)
> 
> diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c
> index 9207621..83e37a9 100644
> --- a/tools/libxl/libxl.c
> +++ b/tools/libxl/libxl.c
> @@ -649,31 +649,30 @@ static void xcinfo2xlinfo(libxl_ctx *ctx,
>  
>  libxl_dominfo * libxl_list_domain(libxl_ctx *ctx, int *nb_domain_out)
>  {
> -    libxl_dominfo *ptr;
> +    libxl_dominfo *ptr = NULL;
>      int i, ret;
>      xc_domaininfo_t info[1024];
> -    int size = 1024;
> +    int size = 0;
> +    uint32_t domid = 0;
>      GC_INIT(ctx);
>  
> -    ptr = calloc(size, sizeof(libxl_dominfo));
> -    if (!ptr) {
> -        LOGE(ERROR, "allocating domain info");
> -        GC_FREE;
> -        return NULL;
> -    }
> -
> -    ret = xc_domain_getinfolist(ctx->xch, 0, 1024, info);
> -    if (ret<0) {
> -        LOGE(ERROR, "getting domain info list");
> -        free(ptr);
> -        GC_FREE;
> -        return NULL;
> +    for (ret = 1; ret;) {
> +        ret = xc_domain_getinfolist(ctx->xch, domid, 1024, info);
> +        if (ret < 0) {
> +            LOGE(ERROR, "getting domain info list");
> +            free(ptr);
> +            GC_FREE;
> +            return NULL;
> +        }
> +        ptr = libxl__realloc(NOGC, ptr, (size + ret) * sizeof(libxl_dominfo));
> +        for (i = 0; i < ret; i++) {
> +            xcinfo2xlinfo(ctx, &info[i], &ptr[size + i]);
> +        }
> +        domid = info[ret - 1].domain + 1;
> +        size += ret;
>      }
>  
> -    for (i = 0; i < ret; i++) {
> -        xcinfo2xlinfo(ctx, &info[i], &ptr[i]);
> -    }
> -    *nb_domain_out = ret;
> +    *nb_domain_out = size;
>      GC_FREE;
>      return ptr;
>  }
>