Re: [Xen-devel] [PATCH] x86/mem_sharing: Relax sanity check for memops
On Fri, May 29, 2015 at 2:37 AM, Tamas K Lengyel
wrote:
> The sharing vm_event ring being enabled is not necessary for mem_sharing
> memops.
>
> Signed-off-by: Tamas K Lengyel
> ---
> xen/arch/x86/mm/mem_sharing.c | 4
> 1 file changed, 4 deletions(-)
>
> diff --git a/xen/arch/x86/mm/mem_sharing.c b/xen/arch/x86/mm/mem_sharing.c
> index 0700f00..16e329e 100644
> --- a/xen/arch/x86/mm/mem_sharing.c
> +++ b/xen/arch/x86/mm/mem_sharing.c
> @@ -1320,10 +1320,6 @@ int
> mem_sharing_memop(XEN_GUEST_HANDLE_PARAM(xen_mem_sharing_op_t) arg)
> if ( !hap_enabled(d) || !d->arch.hvm_domain.mem_sharing_enabled )
> goto out;
>
> -rc = -ENODEV;
> -if ( unlikely(!d->vm_event->share.ring_page) )
> -goto out;
> -
>
Reviewed-by: Andres Lagar-Cavilla
> switch ( mso.op )
> {
> case XENMEM_sharing_op_nominate_gfn:
> --
> 2.1.4
>
>
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Re: [Xen-devel] [PATCH] x86/mem_sharing: Relax sanity check for memops
On Fri, May 29, 2015 at 11:54 AM, Jan Beulich wrote: > >>> On 29.05.15 at 11:37, wrote: > > The sharing vm_event ring being enabled is not necessary for mem_sharing > > memops. > > If indeed so, why would the same not apply to mem_paging memops? > > Jan > The ring during mem_sharing is only used to signal an out-of-memory error condition. If no listener is present for this error condition, Xen will automatically kill the domain that was requesting more memory when none is available during unsharing. For paging, the listener is an absolute requirement as without it paging won't work at all. That's not the case for sharing. Tamas ___ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
Re: [Xen-devel] [PATCH] x86/mem_sharing: Relax sanity check for memops
>>> On 29.05.15 at 11:37, wrote: > The sharing vm_event ring being enabled is not necessary for mem_sharing > memops. If indeed so, why would the same not apply to mem_paging memops? Jan ___ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
[Xen-devel] [PATCH] x86/mem_sharing: Relax sanity check for memops
The sharing vm_event ring being enabled is not necessary for mem_sharing
memops.
Signed-off-by: Tamas K Lengyel
---
xen/arch/x86/mm/mem_sharing.c | 4
1 file changed, 4 deletions(-)
diff --git a/xen/arch/x86/mm/mem_sharing.c b/xen/arch/x86/mm/mem_sharing.c
index 0700f00..16e329e 100644
--- a/xen/arch/x86/mm/mem_sharing.c
+++ b/xen/arch/x86/mm/mem_sharing.c
@@ -1320,10 +1320,6 @@ int
mem_sharing_memop(XEN_GUEST_HANDLE_PARAM(xen_mem_sharing_op_t) arg)
if ( !hap_enabled(d) || !d->arch.hvm_domain.mem_sharing_enabled )
goto out;
-rc = -ENODEV;
-if ( unlikely(!d->vm_event->share.ring_page) )
-goto out;
-
switch ( mso.op )
{
case XENMEM_sharing_op_nominate_gfn:
--
2.1.4
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