Re: [Qemu-devel] [PATCH v3 2/4] kvm: Use inhibit to prevent ballooning without synchronous mmu

[Paolo Bonzini]

On 16/08/2018 20:15, Alex Williamson wrote:
> On Tue,  7 Aug 2018 13:31:23 -0600
> Alex Williamson <address@hidden> wrote:
> 
>> Remove KVM specific tests in balloon_page(), instead marking
>> ballooning as inhibited without KVM_CAP_SYNC_MMU support.
>>
>> Reviewed-by: David Hildenbrand <address@hidden>
>> Reviewed-by: Peter Xu <address@hidden>
>> Reviewed-by: Cornelia Huck <address@hidden>
>> Signed-off-by: Alex Williamson <address@hidden>
>> ---
>>  accel/kvm/kvm-all.c        | 4 ++++
>>  hw/virtio/virtio-balloon.c | 4 +---
>>  2 files changed, 5 insertions(+), 3 deletions(-)
> 
> Paolo and Michael, can I get an ack for this one?  Otherwise I can drop
> it from the series and let this continue to be a special case.  Thanks,
> 
> Alex
>  
>> diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
>> index eb7db92a5e3b..38f468d8e2b1 100644
>> --- a/accel/kvm/kvm-all.c
>> +++ b/accel/kvm/kvm-all.c
>> @@ -39,6 +39,7 @@
>>  #include "trace.h"
>>  #include "hw/irq.h"
>>  #include "sysemu/sev.h"
>> +#include "sysemu/balloon.h"
>>  
>>  #include "hw/boards.h"
>>  
>> @@ -1698,6 +1699,9 @@ static int kvm_init(MachineState *ms)
>>      s->many_ioeventfds = kvm_check_many_ioeventfds();
>>  
>>      s->sync_mmu = !!kvm_vm_check_extension(kvm_state, KVM_CAP_SYNC_MMU);
>> +    if (!s->sync_mmu) {
>> +        qemu_balloon_inhibit(true);
>> +    }
>>  
>>      return 0;
>>  
>> diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c
>> index 1f7a87f09429..b5425080c5fb 100644
>> --- a/hw/virtio/virtio-balloon.c
>> +++ b/hw/virtio/virtio-balloon.c
>> @@ -21,7 +21,6 @@
>>  #include "hw/mem/pc-dimm.h"
>>  #include "sysemu/balloon.h"
>>  #include "hw/virtio/virtio-balloon.h"
>> -#include "sysemu/kvm.h"
>>  #include "exec/address-spaces.h"
>>  #include "qapi/error.h"
>>  #include "qapi/qapi-events-misc.h"
>> @@ -36,8 +35,7 @@
>>  
>>  static void balloon_page(void *addr, int deflate)
>>  {
>> -    if (!qemu_balloon_is_inhibited() && (!kvm_enabled() ||
>> -                                         kvm_has_sync_mmu())) {
>> +    if (!qemu_balloon_is_inhibited()) {
>>          qemu_madvise(addr, BALLOON_PAGE_SIZE,
>>                  deflate ? QEMU_MADV_WILLNEED : QEMU_MADV_DONTNEED);
>>      }
> 

Acked-by: Paolo Bonzini <address@hidden>

Thanks,

Paolo