* [Qemu-devel] file_ram_alloc: unify mem-path, mem-prealloc error handling
@ 2014-02-04 18:41 Marcelo Tosatti
2014-02-04 18:43 ` Marcelo Tosatti
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Marcelo Tosatti @ 2014-02-04 18:41 UTC (permalink / raw)
To: qemu-devel, kvm-devel; +Cc: Paolo Bonzini
-mem-prealloc asks to preallocate memory residing on -mem-path path.
Currently QEMU exits in case:
- Memory file has been created but allocation via explicit write
fails.
And it fallbacks to malloc in case:
- Querying huge page size fails.
- Lack of sync MMU support.
- Open fails.
- mmap fails.
Have the same behaviour for all cases: fail in case -mem-path and
-mem-prealloc are specified for regions where the requested size is
suitable for hugepages.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/exec.c b/exec.c
index 9ad0a4b..1da1ba7 100644
--- a/exec.c
+++ b/exec.c
@@ -996,7 +996,7 @@ static void *file_ram_alloc(RAMBlock *block,
hpagesize = gethugepagesize(path);
if (!hpagesize) {
- return NULL;
+ goto error;
}
if (memory < hpagesize) {
@@ -1005,7 +1005,7 @@ static void *file_ram_alloc(RAMBlock *block,
if (kvm_enabled() && !kvm_has_sync_mmu()) {
fprintf(stderr, "host lacks kvm mmu notifiers, -mem-path unsupported\n");
- return NULL;
+ goto error;
}
/* Make name safe to use with mkstemp by replacing '/' with '_'. */
@@ -1023,7 +1023,7 @@ static void *file_ram_alloc(RAMBlock *block,
if (fd < 0) {
perror("unable to create backing store for hugepages");
g_free(filename);
- return NULL;
+ goto error;
}
unlink(filename);
g_free(filename);
@@ -1043,7 +1043,7 @@ static void *file_ram_alloc(RAMBlock *block,
if (area == MAP_FAILED) {
perror("file_ram_alloc: can't mmap RAM pages");
close(fd);
- return (NULL);
+ goto error;
}
if (mem_prealloc) {
@@ -1087,6 +1087,12 @@ static void *file_ram_alloc(RAMBlock *block,
block->fd = fd;
return area;
+
+error:
+ if (mem_prealloc) {
+ exit(1);
+ }
+ return NULL;
}
#else
static void *file_ram_alloc(RAMBlock *block,
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [Qemu-devel] file_ram_alloc: unify mem-path, mem-prealloc error handling
2014-02-04 18:41 [Qemu-devel] file_ram_alloc: unify mem-path, mem-prealloc error handling Marcelo Tosatti
@ 2014-02-04 18:43 ` Marcelo Tosatti
2014-02-07 8:39 ` Paolo Bonzini
2014-02-27 18:30 ` Paolo Bonzini
2 siblings, 0 replies; 6+ messages in thread
From: Marcelo Tosatti @ 2014-02-04 18:43 UTC (permalink / raw)
To: qemu-devel, kvm-devel; +Cc: Paolo Bonzini
On Tue, Feb 04, 2014 at 01:41:53PM -0500, Marcelo Tosatti wrote:
>
> -mem-prealloc asks to preallocate memory residing on -mem-path path.
>
> Currently QEMU exits in case:
>
> - Memory file has been created but allocation via explicit write
> fails.
>
> And it fallbacks to malloc in case:
> - Querying huge page size fails.
> - Lack of sync MMU support.
> - Open fails.
> - mmap fails.
>
> Have the same behaviour for all cases: fail in case -mem-path and
> -mem-prealloc are specified for regions where the requested size is
> suitable for hugepages.
>
> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Forgot uq/master on the subject (but its aimed for that tree).
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] file_ram_alloc: unify mem-path, mem-prealloc error handling
2014-02-04 18:41 [Qemu-devel] file_ram_alloc: unify mem-path, mem-prealloc error handling Marcelo Tosatti
2014-02-04 18:43 ` Marcelo Tosatti
@ 2014-02-07 8:39 ` Paolo Bonzini
2014-02-27 18:30 ` Paolo Bonzini
2 siblings, 0 replies; 6+ messages in thread
From: Paolo Bonzini @ 2014-02-07 8:39 UTC (permalink / raw)
To: Marcelo Tosatti, qemu-devel, kvm-devel
Il 04/02/2014 19:41, Marcelo Tosatti ha scritto:
>
> -mem-prealloc asks to preallocate memory residing on -mem-path path.
>
> Currently QEMU exits in case:
>
> - Memory file has been created but allocation via explicit write
> fails.
>
> And it fallbacks to malloc in case:
> - Querying huge page size fails.
> - Lack of sync MMU support.
> - Open fails.
> - mmap fails.
>
> Have the same behaviour for all cases: fail in case -mem-path and
> -mem-prealloc are specified for regions where the requested size is
> suitable for hugepages.
>
> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
>
> diff --git a/exec.c b/exec.c
> index 9ad0a4b..1da1ba7 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -996,7 +996,7 @@ static void *file_ram_alloc(RAMBlock *block,
>
> hpagesize = gethugepagesize(path);
> if (!hpagesize) {
> - return NULL;
> + goto error;
> }
>
> if (memory < hpagesize) {
> @@ -1005,7 +1005,7 @@ static void *file_ram_alloc(RAMBlock *block,
>
> if (kvm_enabled() && !kvm_has_sync_mmu()) {
> fprintf(stderr, "host lacks kvm mmu notifiers, -mem-path unsupported\n");
> - return NULL;
> + goto error;
> }
>
> /* Make name safe to use with mkstemp by replacing '/' with '_'. */
> @@ -1023,7 +1023,7 @@ static void *file_ram_alloc(RAMBlock *block,
> if (fd < 0) {
> perror("unable to create backing store for hugepages");
> g_free(filename);
> - return NULL;
> + goto error;
> }
> unlink(filename);
> g_free(filename);
> @@ -1043,7 +1043,7 @@ static void *file_ram_alloc(RAMBlock *block,
> if (area == MAP_FAILED) {
> perror("file_ram_alloc: can't mmap RAM pages");
> close(fd);
> - return (NULL);
> + goto error;
> }
>
> if (mem_prealloc) {
> @@ -1087,6 +1087,12 @@ static void *file_ram_alloc(RAMBlock *block,
>
> block->fd = fd;
> return area;
> +
> +error:
> + if (mem_prealloc) {
> + exit(1);
> + }
> + return NULL;
> }
> #else
> static void *file_ram_alloc(RAMBlock *block,
>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Will apply soon.
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [Qemu-devel] file_ram_alloc: unify mem-path, mem-prealloc error handling
2014-02-04 18:41 [Qemu-devel] file_ram_alloc: unify mem-path, mem-prealloc error handling Marcelo Tosatti
2014-02-04 18:43 ` Marcelo Tosatti
2014-02-07 8:39 ` Paolo Bonzini
@ 2014-02-27 18:30 ` Paolo Bonzini
2014-02-28 1:05 ` Marcelo Tosatti
2014-02-28 12:55 ` Igor Mammedov
2 siblings, 2 replies; 6+ messages in thread
From: Paolo Bonzini @ 2014-02-27 18:30 UTC (permalink / raw)
To: Marcelo Tosatti, qemu-devel, kvm-devel
Il 04/02/2014 19:41, Marcelo Tosatti ha scritto:
>
> -mem-prealloc asks to preallocate memory residing on -mem-path path.
>
> Currently QEMU exits in case:
>
> - Memory file has been created but allocation via explicit write
> fails.
>
> And it fallbacks to malloc in case:
> - Querying huge page size fails.
> - Lack of sync MMU support.
> - Open fails.
> - mmap fails.
>
> Have the same behaviour for all cases: fail in case -mem-path and
> -mem-prealloc are specified for regions where the requested size is
> suitable for hugepages.
>
> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Once we introduce memdev, I believe -mem-path should always exit, and
never fall back to malloc/MAP_ANON.
For 2.0, I'm applying the patch to uq/master.
Paolo
> diff --git a/exec.c b/exec.c
> index 9ad0a4b..1da1ba7 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -996,7 +996,7 @@ static void *file_ram_alloc(RAMBlock *block,
>
> hpagesize = gethugepagesize(path);
> if (!hpagesize) {
> - return NULL;
> + goto error;
> }
>
> if (memory < hpagesize) {
> @@ -1005,7 +1005,7 @@ static void *file_ram_alloc(RAMBlock *block,
>
> if (kvm_enabled() && !kvm_has_sync_mmu()) {
> fprintf(stderr, "host lacks kvm mmu notifiers, -mem-path unsupported\n");
> - return NULL;
> + goto error;
> }
>
> /* Make name safe to use with mkstemp by replacing '/' with '_'. */
> @@ -1023,7 +1023,7 @@ static void *file_ram_alloc(RAMBlock *block,
> if (fd < 0) {
> perror("unable to create backing store for hugepages");
> g_free(filename);
> - return NULL;
> + goto error;
> }
> unlink(filename);
> g_free(filename);
> @@ -1043,7 +1043,7 @@ static void *file_ram_alloc(RAMBlock *block,
> if (area == MAP_FAILED) {
> perror("file_ram_alloc: can't mmap RAM pages");
> close(fd);
> - return (NULL);
> + goto error;
> }
>
> if (mem_prealloc) {
> @@ -1087,6 +1087,12 @@ static void *file_ram_alloc(RAMBlock *block,
>
> block->fd = fd;
> return area;
> +
> +error:
> + if (mem_prealloc) {
> + exit(1);
> + }
> + return NULL;
> }
> #else
> static void *file_ram_alloc(RAMBlock *block,
>
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [Qemu-devel] file_ram_alloc: unify mem-path, mem-prealloc error handling
2014-02-27 18:30 ` Paolo Bonzini
@ 2014-02-28 1:05 ` Marcelo Tosatti
2014-02-28 12:55 ` Igor Mammedov
1 sibling, 0 replies; 6+ messages in thread
From: Marcelo Tosatti @ 2014-02-28 1:05 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: qemu-devel, kvm-devel
On Thu, Feb 27, 2014 at 07:30:26PM +0100, Paolo Bonzini wrote:
> Il 04/02/2014 19:41, Marcelo Tosatti ha scritto:
> >
> >-mem-prealloc asks to preallocate memory residing on -mem-path path.
> >
> >Currently QEMU exits in case:
> >
> >- Memory file has been created but allocation via explicit write
> >fails.
> >
> >And it fallbacks to malloc in case:
> >- Querying huge page size fails.
> >- Lack of sync MMU support.
> >- Open fails.
> >- mmap fails.
> >
> >Have the same behaviour for all cases: fail in case -mem-path and
> >-mem-prealloc are specified for regions where the requested size is
> >suitable for hugepages.
> >
> >Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
>
> Once we introduce memdev, I believe -mem-path should always exit,
> and never fall back to malloc/MAP_ANON.
Agree.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] file_ram_alloc: unify mem-path, mem-prealloc error handling
2014-02-27 18:30 ` Paolo Bonzini
2014-02-28 1:05 ` Marcelo Tosatti
@ 2014-02-28 12:55 ` Igor Mammedov
1 sibling, 0 replies; 6+ messages in thread
From: Igor Mammedov @ 2014-02-28 12:55 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: Marcelo Tosatti, qemu-devel, kvm-devel
On Thu, 27 Feb 2014 19:30:26 +0100
Paolo Bonzini <pbonzini@redhat.com> wrote:
> Il 04/02/2014 19:41, Marcelo Tosatti ha scritto:
> >
> > -mem-prealloc asks to preallocate memory residing on -mem-path path.
> >
> > Currently QEMU exits in case:
> >
> > - Memory file has been created but allocation via explicit write
> > fails.
> >
> > And it fallbacks to malloc in case:
> > - Querying huge page size fails.
> > - Lack of sync MMU support.
> > - Open fails.
> > - mmap fails.
> >
> > Have the same behaviour for all cases: fail in case -mem-path and
> > -mem-prealloc are specified for regions where the requested size is
> > suitable for hugepages.
> >
> > Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
>
> Once we introduce memdev, I believe -mem-path should always exit, and
> never fall back to malloc/MAP_ANON.
perhaps it should return a error instead of exit.
Exit would be bad for hotplug case, hotplug op should fail and not crash machine.
> For 2.0, I'm applying the patch to uq/master.
>
> Paolo
>
> > diff --git a/exec.c b/exec.c
> > index 9ad0a4b..1da1ba7 100644
> > --- a/exec.c
> > +++ b/exec.c
> > @@ -996,7 +996,7 @@ static void *file_ram_alloc(RAMBlock *block,
> >
> > hpagesize = gethugepagesize(path);
> > if (!hpagesize) {
> > - return NULL;
> > + goto error;
> > }
> >
> > if (memory < hpagesize) {
> > @@ -1005,7 +1005,7 @@ static void *file_ram_alloc(RAMBlock *block,
> >
> > if (kvm_enabled() && !kvm_has_sync_mmu()) {
> > fprintf(stderr, "host lacks kvm mmu notifiers, -mem-path unsupported\n");
> > - return NULL;
> > + goto error;
> > }
> >
> > /* Make name safe to use with mkstemp by replacing '/' with '_'. */
> > @@ -1023,7 +1023,7 @@ static void *file_ram_alloc(RAMBlock *block,
> > if (fd < 0) {
> > perror("unable to create backing store for hugepages");
> > g_free(filename);
> > - return NULL;
> > + goto error;
> > }
> > unlink(filename);
> > g_free(filename);
> > @@ -1043,7 +1043,7 @@ static void *file_ram_alloc(RAMBlock *block,
> > if (area == MAP_FAILED) {
> > perror("file_ram_alloc: can't mmap RAM pages");
> > close(fd);
> > - return (NULL);
> > + goto error;
> > }
> >
> > if (mem_prealloc) {
> > @@ -1087,6 +1087,12 @@ static void *file_ram_alloc(RAMBlock *block,
> >
> > block->fd = fd;
> > return area;
> > +
> > +error:
> > + if (mem_prealloc) {
> > + exit(1);
> > + }
> > + return NULL;
> > }
> > #else
> > static void *file_ram_alloc(RAMBlock *block,
> >
>
>
^ permalink raw reply [flat|nested] 6+ messages in thread
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2014-02-04 18:41 [Qemu-devel] file_ram_alloc: unify mem-path, mem-prealloc error handling Marcelo Tosatti
2014-02-04 18:43 ` Marcelo Tosatti
2014-02-07 8:39 ` Paolo Bonzini
2014-02-27 18:30 ` Paolo Bonzini
2014-02-28 1:05 ` Marcelo Tosatti
2014-02-28 12:55 ` Igor Mammedov
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