* [PATCH] Qemu: Add sanity check for vcpu config
@ 2010-03-21 15:09 Liu, Jinsong
2010-03-21 17:15 ` Keir Fraser
0 siblings, 1 reply; 7+ messages in thread
From: Liu, Jinsong @ 2010-03-21 15:09 UTC (permalink / raw)
To: xen-devel; +Cc: Ian Jackson, Keir Fraser
[-- Attachment #1: Type: text/plain, Size: 2027 bytes --]
>From 4d483620c863f626543fdc407c2951ceef49623e Mon Sep 17 00:00:00 2001
From: Liu, Jinsong <jinsong.liu@intel.com>
Date: Sun, 21 Mar 2010 22:48:04 +0800
Subject: [PATCH] Qemu: Add sanity check for vcpu config
Currently Xen/Qemu support max 128 vcpus. To avoid mis-setting
at config file, this patch add sanity check for vcpu config.
1. maxvcpus and vcpus should no more than HVM_MAX_VCPUS (128)
2. vcpus should no more than maxvcpus.
Signed-off-by: Liu, Jinsong <jinsong.liu@intel.com>
---
vl.c | 30 ++++++++++++++++++++++++++++++
1 files changed, 30 insertions(+), 0 deletions(-)
diff --git a/vl.c b/vl.c
index 30debd7..d69d90c 100644
--- a/vl.c
+++ b/vl.c
@@ -4706,6 +4706,34 @@ static void termsig_setup(void)
#endif
+/* 32bit Hamming weight */
+unsigned int hweight32(unsigned int w)
+{
+ unsigned int res = w - ((w >> 1) & 0x55555555);
+ res = (res & 0x33333333) + ((res >> 2) & 0x33333333);
+ res = (res + (res >> 4)) & 0x0F0F0F0F;
+ res = res + (res >> 8);
+ return (res + (res >> 16)) & 0x000000FF;
+}
+
+static void vcpu_sanity_check(void)
+{
+ int i, vcpu_avail_weight = 0;
+
+ for (i=0; i<((HVM_MAX_VCPUS + 31)/32); i++)
+ vcpu_avail_weight += hweight32(vcpu_avail[i]);
+
+ if (vcpus > HVM_MAX_VCPUS) {
+ fprintf(stderr, "maxvcpus and vcpus should not more than %d\n",
+ HVM_MAX_VCPUS);
+ exit(EXIT_FAILURE);
+ }
+ if (vcpu_avail_weight > vcpus) {
+ fprintf(stderr, "vcpus should not more than maxvcpus\n");
+ exit(EXIT_FAILURE);
+ }
+}
+
#define STEP 8 /* 8 characters fill uint32_t bitmap */
#define SPACE 8 /* space for non-hex characters in vcpu str */
#define MAX_VCPU_STR_LEN ((HVM_MAX_VCPUS + 3)/4 + SPACE)
@@ -5569,6 +5597,8 @@ int main(int argc, char **argv, char **envp)
exit(1);
}
+ vcpu_sanity_check();
+
if (nographic) {
if (serial_device_index == 0)
serial_devices[0] = "stdio";
--
1.5.6.4
[-- Attachment #2: qemu-vcpu-sanity-check.patch --]
[-- Type: application/octet-stream, Size: 2028 bytes --]
From 4d483620c863f626543fdc407c2951ceef49623e Mon Sep 17 00:00:00 2001
From: Liu, Jinsong <jinsong.liu@intel.com>
Date: Sun, 21 Mar 2010 22:48:04 +0800
Subject: [PATCH] Qemu: Add sanity check for vcpu config
Currently Xen/Qemu support max 128 vcpus. To avoid mis-setting
at config file, this patch add sanity check for vcpu config.
1. maxvcpus and vcpus should no more than HVM_MAX_VCPUS (128)
2. vcpus should no more than maxvcpus.
Signed-off-by: Liu, Jinsong <jinsong.liu@intel.com>
---
vl.c | 30 ++++++++++++++++++++++++++++++
1 files changed, 30 insertions(+), 0 deletions(-)
diff --git a/vl.c b/vl.c
index 30debd7..d69d90c 100644
--- a/vl.c
+++ b/vl.c
@@ -4706,6 +4706,34 @@ static void termsig_setup(void)
#endif
+/* 32bit Hamming weight */
+unsigned int hweight32(unsigned int w)
+{
+ unsigned int res = w - ((w >> 1) & 0x55555555);
+ res = (res & 0x33333333) + ((res >> 2) & 0x33333333);
+ res = (res + (res >> 4)) & 0x0F0F0F0F;
+ res = res + (res >> 8);
+ return (res + (res >> 16)) & 0x000000FF;
+}
+
+static void vcpu_sanity_check(void)
+{
+ int i, vcpu_avail_weight = 0;
+
+ for (i=0; i<((HVM_MAX_VCPUS + 31)/32); i++)
+ vcpu_avail_weight += hweight32(vcpu_avail[i]);
+
+ if (vcpus > HVM_MAX_VCPUS) {
+ fprintf(stderr, "maxvcpus and vcpus should not more than %d\n",
+ HVM_MAX_VCPUS);
+ exit(EXIT_FAILURE);
+ }
+ if (vcpu_avail_weight > vcpus) {
+ fprintf(stderr, "vcpus should not more than maxvcpus\n");
+ exit(EXIT_FAILURE);
+ }
+}
+
#define STEP 8 /* 8 characters fill uint32_t bitmap */
#define SPACE 8 /* space for non-hex characters in vcpu str */
#define MAX_VCPU_STR_LEN ((HVM_MAX_VCPUS + 3)/4 + SPACE)
@@ -5569,6 +5597,8 @@ int main(int argc, char **argv, char **envp)
exit(1);
}
+ vcpu_sanity_check();
+
if (nographic) {
if (serial_device_index == 0)
serial_devices[0] = "stdio";
--
1.5.6.4
[-- Attachment #3: Type: text/plain, Size: 138 bytes --]
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xensource.com
http://lists.xensource.com/xen-devel
^ permalink raw reply related [flat|nested] 7+ messages in thread* Re: [PATCH] Qemu: Add sanity check for vcpu config
2010-03-21 15:09 [PATCH] Qemu: Add sanity check for vcpu config Liu, Jinsong
@ 2010-03-21 17:15 ` Keir Fraser
2010-03-22 17:21 ` Ian Jackson
0 siblings, 1 reply; 7+ messages in thread
From: Keir Fraser @ 2010-03-21 17:15 UTC (permalink / raw)
To: Liu, Jinsong, xen-devel; +Cc: Ian Jackson
Wouldn't xend be a more sensible place to do the check? It can certainly
result in a better error message, I would have thought.
-- Keir
On 21/03/2010 15:09, "Liu, Jinsong" <jinsong.liu@intel.com> wrote:
> From 4d483620c863f626543fdc407c2951ceef49623e Mon Sep 17 00:00:00 2001
> From: Liu, Jinsong <jinsong.liu@intel.com>
> Date: Sun, 21 Mar 2010 22:48:04 +0800
> Subject: [PATCH] Qemu: Add sanity check for vcpu config
>
> Currently Xen/Qemu support max 128 vcpus. To avoid mis-setting
> at config file, this patch add sanity check for vcpu config.
> 1. maxvcpus and vcpus should no more than HVM_MAX_VCPUS (128)
> 2. vcpus should no more than maxvcpus.
>
> Signed-off-by: Liu, Jinsong <jinsong.liu@intel.com>
> ---
> vl.c | 30 ++++++++++++++++++++++++++++++
> 1 files changed, 30 insertions(+), 0 deletions(-)
>
> diff --git a/vl.c b/vl.c
> index 30debd7..d69d90c 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -4706,6 +4706,34 @@ static void termsig_setup(void)
>
> #endif
>
> +/* 32bit Hamming weight */
> +unsigned int hweight32(unsigned int w)
> +{
> + unsigned int res = w - ((w >> 1) & 0x55555555);
> + res = (res & 0x33333333) + ((res >> 2) & 0x33333333);
> + res = (res + (res >> 4)) & 0x0F0F0F0F;
> + res = res + (res >> 8);
> + return (res + (res >> 16)) & 0x000000FF;
> +}
> +
> +static void vcpu_sanity_check(void)
> +{
> + int i, vcpu_avail_weight = 0;
> +
> + for (i=0; i<((HVM_MAX_VCPUS + 31)/32); i++)
> + vcpu_avail_weight += hweight32(vcpu_avail[i]);
> +
> + if (vcpus > HVM_MAX_VCPUS) {
> + fprintf(stderr, "maxvcpus and vcpus should not more than %d\n",
> + HVM_MAX_VCPUS);
> + exit(EXIT_FAILURE);
> + }
> + if (vcpu_avail_weight > vcpus) {
> + fprintf(stderr, "vcpus should not more than maxvcpus\n");
> + exit(EXIT_FAILURE);
> + }
> +}
> +
> #define STEP 8 /* 8 characters fill uint32_t bitmap */
> #define SPACE 8 /* space for non-hex characters in vcpu str */
> #define MAX_VCPU_STR_LEN ((HVM_MAX_VCPUS + 3)/4 + SPACE)
> @@ -5569,6 +5597,8 @@ int main(int argc, char **argv, char **envp)
> exit(1);
> }
>
> + vcpu_sanity_check();
> +
> if (nographic) {
> if (serial_device_index == 0)
> serial_devices[0] = "stdio";
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH] Qemu: Add sanity check for vcpu config
2010-03-21 17:15 ` Keir Fraser
@ 2010-03-22 17:21 ` Ian Jackson
2010-03-23 2:17 ` Liu, Jinsong
0 siblings, 1 reply; 7+ messages in thread
From: Ian Jackson @ 2010-03-22 17:21 UTC (permalink / raw)
To: Keir Fraser; +Cc: Liu, Jinsong, xen-devel
Keir Fraser writes ("[Xen-devel] Re: [PATCH] Qemu: Add sanity check for vcpu config"):
> Wouldn't xend be a more sensible place to do the check? It can certainly
> result in a better error message, I would have thought.
Quite so. If you add feature to xend, it should be changed in libxl
too.
Ian.
^ permalink raw reply [flat|nested] 7+ messages in thread* RE: Re: [PATCH] Qemu: Add sanity check for vcpu config
2010-03-22 17:21 ` Ian Jackson
@ 2010-03-23 2:17 ` Liu, Jinsong
2010-03-23 7:22 ` Keir Fraser
2010-03-24 11:20 ` Ian Jackson
0 siblings, 2 replies; 7+ messages in thread
From: Liu, Jinsong @ 2010-03-23 2:17 UTC (permalink / raw)
To: Ian Jackson, Keir Fraser; +Cc: xen-devel
Keir,
Have you decided where should vcpu sanity check be located?
We add vcpu sanity check at qemu because:
1. xen/qemu itself has knowledge like HVM_MAX_VCPUS, xend doesn't have such knowledge;
2. there are many ways to transfer config/cmdline para to qemu, xm/xend is one of them which used at Xen. On other system like KVM, there is no xm/xend at all. So naturely qemu is a better place to do sanity check than xend;
3. even if we add sanity check at xend, qemu still need do sanity check. After all, qemu cannot totally trust its input;
Thanks,
Jinsong
Ian Jackson wrote:
> Keir Fraser writes ("[Xen-devel] Re: [PATCH] Qemu: Add sanity check
> for vcpu config"):
>> Wouldn't xend be a more sensible place to do the check? It can
>> certainly result in a better error message, I would have thought.
>
> Quite so. If you add feature to xend, it should be changed in libxl
> too.
>
> Ian.
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: Re: [PATCH] Qemu: Add sanity check for vcpu config
2010-03-23 2:17 ` Liu, Jinsong
@ 2010-03-23 7:22 ` Keir Fraser
2010-03-23 8:07 ` Liu, Jinsong
2010-03-24 11:20 ` Ian Jackson
1 sibling, 1 reply; 7+ messages in thread
From: Keir Fraser @ 2010-03-23 7:22 UTC (permalink / raw)
To: Liu, Jinsong, Ian Jackson; +Cc: xen-devel
I'm not dead against a sanity check in qemu.
-- Keir
On 23/03/2010 02:17, "Liu, Jinsong" <jinsong.liu@intel.com> wrote:
> Keir,
>
> Have you decided where should vcpu sanity check be located?
> We add vcpu sanity check at qemu because:
> 1. xen/qemu itself has knowledge like HVM_MAX_VCPUS, xend doesn't have such
> knowledge;
> 2. there are many ways to transfer config/cmdline para to qemu, xm/xend is one
> of them which used at Xen. On other system like KVM, there is no xm/xend at
> all. So naturely qemu is a better place to do sanity check than xend;
> 3. even if we add sanity check at xend, qemu still need do sanity check. After
> all, qemu cannot totally trust its input;
>
> Thanks,
> Jinsong
>
> Ian Jackson wrote:
>> Keir Fraser writes ("[Xen-devel] Re: [PATCH] Qemu: Add sanity check
>> for vcpu config"):
>>> Wouldn't xend be a more sensible place to do the check? It can
>>> certainly result in a better error message, I would have thought.
>>
>> Quite so. If you add feature to xend, it should be changed in libxl
>> too.
>>
>> Ian.
>>
>> _______________________________________________
>> Xen-devel mailing list
>> Xen-devel@lists.xensource.com
>> http://lists.xensource.com/xen-devel
>
^ permalink raw reply [flat|nested] 7+ messages in thread* RE: Re: [PATCH] Qemu: Add sanity check for vcpu config
2010-03-23 7:22 ` Keir Fraser
@ 2010-03-23 8:07 ` Liu, Jinsong
0 siblings, 0 replies; 7+ messages in thread
From: Liu, Jinsong @ 2010-03-23 8:07 UTC (permalink / raw)
To: Keir Fraser, Ian Jackson; +Cc: xen-devel
Yes, I know :)
I just speaking out my thinking.
Thanks,
Jinsong
Keir Fraser wrote:
> I'm not dead against a sanity check in qemu.
>
> -- Keir
>
> On 23/03/2010 02:17, "Liu, Jinsong" <jinsong.liu@intel.com> wrote:
>
>> Keir,
>>
>> Have you decided where should vcpu sanity check be located?
>> We add vcpu sanity check at qemu because:
>> 1. xen/qemu itself has knowledge like HVM_MAX_VCPUS, xend doesn't
>> have such knowledge;
>> 2. there are many ways to transfer config/cmdline para to qemu,
>> xm/xend is one of them which used at Xen. On other system like KVM,
>> there is no xm/xend at all. So naturely qemu is a better place to do
>> sanity check than xend;
>> 3. even if we add sanity check at xend, qemu still need do sanity
>> check. After all, qemu cannot totally trust its input;
>>
>> Thanks,
>> Jinsong
>>
>> Ian Jackson wrote:
>>> Keir Fraser writes ("[Xen-devel] Re: [PATCH] Qemu: Add sanity check
>>> for vcpu config"):
>>>> Wouldn't xend be a more sensible place to do the check? It can
>>>> certainly result in a better error message, I would have thought.
>>>
>>> Quite so. If you add feature to xend, it should be changed in
>>> libxl too.
>>>
>>> Ian.
>>>
>>> _______________________________________________
>>> Xen-devel mailing list
>>> Xen-devel@lists.xensource.com
>>> http://lists.xensource.com/xen-devel
^ permalink raw reply [flat|nested] 7+ messages in thread
* RE: Re: [PATCH] Qemu: Add sanity check for vcpu config
2010-03-23 2:17 ` Liu, Jinsong
2010-03-23 7:22 ` Keir Fraser
@ 2010-03-24 11:20 ` Ian Jackson
1 sibling, 0 replies; 7+ messages in thread
From: Ian Jackson @ 2010-03-24 11:20 UTC (permalink / raw)
To: Liu, Jinsong; +Cc: xen-devel, Keir Fraser
Liu, Jinsong writes ("RE: [Xen-devel] Re: [PATCH] Qemu: Add sanity check for vcpu config"):
> 3. even if we add sanity check at xend, qemu still need do sanity
> check. After all, qemu cannot totally trust its input;
This is a very good argument. I will apply your patch.
Ian.
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2010-03-24 11:20 UTC | newest]
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2010-03-21 15:09 [PATCH] Qemu: Add sanity check for vcpu config Liu, Jinsong
2010-03-21 17:15 ` Keir Fraser
2010-03-22 17:21 ` Ian Jackson
2010-03-23 2:17 ` Liu, Jinsong
2010-03-23 7:22 ` Keir Fraser
2010-03-23 8:07 ` Liu, Jinsong
2010-03-24 11:20 ` Ian Jackson
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