[PATCH] KVM: arm64: Increase number of memslots to 512

[Linu Cherian]

On Tue, Feb 7, 2017 at 3:46 PM, Auger Eric <eric.auger at redhat.com> wrote:
> Hi Linu,
>
> On 11/01/2017 17:52, linucherian at gmail.com wrote:
>> From: Linu Cherian <linu.cherian at cavium.com>
>>
>> Having only 32 memslots is a real constraint for the maximum number of
>> PCI devices that can be assigned to a single guest. Assuming each PCI
>> device/virtual function having two memory BAR regions, we could assign
>> only 15 devices/virtual functions to a guest.
>>
>> So increase KVM_MEM_SLOTS_NUM to 512 as done in other archs like x86 and
>> powerpc. For this, KVM_USER_MEM_SLOTS has been changed to 508.
>>
>> Signed-off-by: Linu Cherian <linu.cherian at cavium.com>
>
>> ---
>>  arch/arm/kvm/arm.c                | 3 +++
>>  arch/arm64/include/asm/kvm_host.h | 2 +-
>>  2 files changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
>> index 8f92efa..a19389b 100644
>> --- a/arch/arm/kvm/arm.c
>> +++ b/arch/arm/kvm/arm.c
>> @@ -221,6 +221,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
>>       case KVM_CAP_MAX_VCPUS:
>>               r = KVM_MAX_VCPUS;
>>               break;
>> +     case KVM_CAP_NR_MEMSLOTS:
>> +             r = KVM_USER_MEM_SLOTS;
>> +             break;
> This change is not documented in the commit message and I think it
> should since we now allow KVM/ARM to report the number of available user
> mem slots. I would personally suggest to put it in a sepate patch as it
> was done on s390 for instance
> (http://marc.info/?l=linux-s390&m=136422861316920&w=2)
>

Thanks for reviewing. Will send out another version with this fixed.