[Qemu-devel] [RFC PATCH v0 1/2] kvm: API to obtain max supported mem slots

[Qemu-devel] [RFC PATCH v0 1/2] kvm: API to obtain max supported mem slots

[Bharata B Rao]

Introduce kvm_get_max_memslots() API that can be used to obtain the
maximum number of memslots supported by KVM.

Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
---
 include/sysemu/kvm.h | 1 +
 kvm-all.c            | 7 +++++++
 2 files changed, 8 insertions(+)

diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h
index 65569ed..ad6f837 100644
--- a/include/sysemu/kvm.h
+++ b/include/sysemu/kvm.h
@@ -527,4 +527,5 @@ int kvm_set_one_reg(CPUState *cs, uint64_t id, void *source);
  * Returns: 0 on success, or a negative errno on failure.
  */
 int kvm_get_one_reg(CPUState *cs, uint64_t id, void *target);
+int kvm_get_max_memslots(void);
 #endif
diff --git a/kvm-all.c b/kvm-all.c
index d317dcb..fbd2d93 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -126,6 +126,13 @@ static const KVMCapabilityInfo kvm_required_capabilites[] = {
     KVM_CAP_LAST_INFO
 };
 
+int kvm_get_max_memslots(void)
+{
+    KVMState *s = KVM_STATE(current_machine->accelerator);
+
+    return s->nr_slots;
+}
+
 static KVMSlot *kvm_get_free_slot(KVMMemoryListener *kml)
 {
     KVMState *s = kvm_state;
-- 
2.1.0

[Qemu-devel] [RFC PATCH v0 2/2] spapr: Increase max memslots to 512

[Bharata B Rao]

KVM now supports 512 memslots on PowerPC (earlier it was 32). Hence allow
user to specify a max of 512 hotpluggable memory slots.

Instead of hard coding the max value, use the KVM supplied value if KVM
is enabled. Otherwise resort to the default value of 32.

Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
---
 hw/ppc/spapr.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 44e401a..3de426e 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -1816,11 +1816,13 @@ static void ppc_spapr_init(MachineState *machine)
     /* initialize hotplug memory address space */
     if (machine->ram_size < machine->maxram_size) {
         ram_addr_t hotplug_mem_size = machine->maxram_size - machine->ram_size;
+        int max_memslots = kvm_enabled() ? kvm_get_max_memslots() :
+                           SPAPR_MAX_RAM_SLOTS;
 
-        if (machine->ram_slots > SPAPR_MAX_RAM_SLOTS) {
+        if (machine->ram_slots > max_memslots) {
             error_report("Specified number of memory slots %"
                          PRIu64" exceeds max supported %d",
-                         machine->ram_slots, SPAPR_MAX_RAM_SLOTS);
+                         machine->ram_slots, max_memslots);
             exit(1);
         }
 
-- 
2.1.0

Re: [Qemu-devel] [RFC PATCH v0 1/2] kvm: API to obtain max supported mem slots

[Paolo Bonzini]

On 01/06/2016 11:51, Bharata B Rao wrote:
> Introduce kvm_get_max_memslots() API that can be used to obtain the
> maximum number of memslots supported by KVM.
> 
> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
> ---
>  include/sysemu/kvm.h | 1 +
>  kvm-all.c            | 7 +++++++
>  2 files changed, 8 insertions(+)
> 
> diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h
> index 65569ed..ad6f837 100644
> --- a/include/sysemu/kvm.h
> +++ b/include/sysemu/kvm.h
> @@ -527,4 +527,5 @@ int kvm_set_one_reg(CPUState *cs, uint64_t id, void *source);
>   * Returns: 0 on success, or a negative errno on failure.
>   */
>  int kvm_get_one_reg(CPUState *cs, uint64_t id, void *target);
> +int kvm_get_max_memslots(void);
>  #endif
> diff --git a/kvm-all.c b/kvm-all.c
> index d317dcb..fbd2d93 100644
> --- a/kvm-all.c
> +++ b/kvm-all.c
> @@ -126,6 +126,13 @@ static const KVMCapabilityInfo kvm_required_capabilites[] = {
>      KVM_CAP_LAST_INFO
>  };
>  
> +int kvm_get_max_memslots(void)
> +{
> +    KVMState *s = KVM_STATE(current_machine->accelerator);
> +
> +    return s->nr_slots;
> +}
> +
>  static KVMSlot *kvm_get_free_slot(KVMMemoryListener *kml)
>  {
>      KVMState *s = kvm_state;
> 

Acked-by: Paolo Bonzini <pbonzini@redhat.com>

Re: [Qemu-devel] [RFC PATCH v0 1/2] kvm: API to obtain max supported mem slots

[David Gibson]

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On Wed, Jun 01, 2016 at 11:56:07AM +0200, Paolo Bonzini wrote:
> 
> 
> On 01/06/2016 11:51, Bharata B Rao wrote:
> > Introduce kvm_get_max_memslots() API that can be used to obtain the
> > maximum number of memslots supported by KVM.
> > 
> > Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
> > ---
> >  include/sysemu/kvm.h | 1 +
> >  kvm-all.c            | 7 +++++++
> >  2 files changed, 8 insertions(+)
> > 
> > diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h
> > index 65569ed..ad6f837 100644
> > --- a/include/sysemu/kvm.h
> > +++ b/include/sysemu/kvm.h
> > @@ -527,4 +527,5 @@ int kvm_set_one_reg(CPUState *cs, uint64_t id, void *source);
> >   * Returns: 0 on success, or a negative errno on failure.
> >   */
> >  int kvm_get_one_reg(CPUState *cs, uint64_t id, void *target);
> > +int kvm_get_max_memslots(void);
> >  #endif
> > diff --git a/kvm-all.c b/kvm-all.c
> > index d317dcb..fbd2d93 100644
> > --- a/kvm-all.c
> > +++ b/kvm-all.c
> > @@ -126,6 +126,13 @@ static const KVMCapabilityInfo kvm_required_capabilites[] = {
> >      KVM_CAP_LAST_INFO
> >  };
> >  
> > +int kvm_get_max_memslots(void)
> > +{
> > +    KVMState *s = KVM_STATE(current_machine->accelerator);
> > +
> > +    return s->nr_slots;
> > +}
> > +
> >  static KVMSlot *kvm_get_free_slot(KVMMemoryListener *kml)
> >  {
> >      KVMState *s = kvm_state;
> > 
> 
> Acked-by: Paolo Bonzini <pbonzini@redhat.com>

Thanks for the ack, I've merged this into my tree.

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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