From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Huth Date: Wed, 18 Nov 2015 16:19:51 +0000 Subject: Re: [PATCH 1/1] KVM: PPC: Increase memslots to 320 Message-Id: <564CA527.8020903@redhat.com> List-Id: References: <1446627828-3347-1-git-send-email-thuth@redhat.com> <1446627828-3347-2-git-send-email-thuth@redhat.com> In-Reply-To: <1446627828-3347-2-git-send-email-thuth@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: kvm-ppc@vger.kernel.org, Paul Mackerras Cc: kvm@vger.kernel.org, scottwood@freescale.com, Alexander Graf , nikunj@linux.vnet.ibm.com On 04/11/15 10:03, Thomas Huth wrote: > Only using 32 memslots for KVM on powerpc is way too low, you can > nowadays hit this limit quite fast by adding a couple of PCI devices > and/or pluggable memory DIMMs to the guest. > x86 already increased the limit to 512 in total, to satisfy 256 > pluggable DIMM slots, 3 private slots and 253 slots for other things > like PCI devices. On powerpc, we only have 32 pluggable DIMMs in > QEMU, not 256, so we likely do not as much slots as on x86. Thus > setting the slot limit to 320 sounds like a good value for the > time being (until we have some code in the future to resize the > memslot array dynamically). > And while we're at it, also remove the KVM_MEM_SLOTS_NUM definition > from the powerpc-specific header since this gets defined in the > generic kvm_host.h header anyway. > > Signed-off-by: Thomas Huth > --- > arch/powerpc/include/asm/kvm_host.h | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h > index 887c259..89d387a 100644 > --- a/arch/powerpc/include/asm/kvm_host.h > +++ b/arch/powerpc/include/asm/kvm_host.h > @@ -38,8 +38,7 @@ > > #define KVM_MAX_VCPUS NR_CPUS > #define KVM_MAX_VCORES NR_CPUS > -#define KVM_USER_MEM_SLOTS 32 > -#define KVM_MEM_SLOTS_NUM KVM_USER_MEM_SLOTS > +#define KVM_USER_MEM_SLOTS 320 > > #ifdef CONFIG_KVM_MMIO > #define KVM_COALESCED_MMIO_PAGE_OFFSET 1 > Ping! ... any comments on this one? Thomas From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Huth Subject: Re: [PATCH 1/1] KVM: PPC: Increase memslots to 320 Date: Wed, 18 Nov 2015 17:19:51 +0100 Message-ID: <564CA527.8020903@redhat.com> References: <1446627828-3347-1-git-send-email-thuth@redhat.com> <1446627828-3347-2-git-send-email-thuth@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, scottwood@freescale.com, Alexander Graf , nikunj@linux.vnet.ibm.com To: kvm-ppc@vger.kernel.org, Paul Mackerras Return-path: Received: from mx1.redhat.com ([209.132.183.28]:47063 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932099AbbKRQTz (ORCPT ); Wed, 18 Nov 2015 11:19:55 -0500 In-Reply-To: <1446627828-3347-2-git-send-email-thuth@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 04/11/15 10:03, Thomas Huth wrote: > Only using 32 memslots for KVM on powerpc is way too low, you can > nowadays hit this limit quite fast by adding a couple of PCI devices > and/or pluggable memory DIMMs to the guest. > x86 already increased the limit to 512 in total, to satisfy 256 > pluggable DIMM slots, 3 private slots and 253 slots for other things > like PCI devices. On powerpc, we only have 32 pluggable DIMMs in > QEMU, not 256, so we likely do not as much slots as on x86. Thus > setting the slot limit to 320 sounds like a good value for the > time being (until we have some code in the future to resize the > memslot array dynamically). > And while we're at it, also remove the KVM_MEM_SLOTS_NUM definition > from the powerpc-specific header since this gets defined in the > generic kvm_host.h header anyway. > > Signed-off-by: Thomas Huth > --- > arch/powerpc/include/asm/kvm_host.h | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h > index 887c259..89d387a 100644 > --- a/arch/powerpc/include/asm/kvm_host.h > +++ b/arch/powerpc/include/asm/kvm_host.h > @@ -38,8 +38,7 @@ > > #define KVM_MAX_VCPUS NR_CPUS > #define KVM_MAX_VCORES NR_CPUS > -#define KVM_USER_MEM_SLOTS 32 > -#define KVM_MEM_SLOTS_NUM KVM_USER_MEM_SLOTS > +#define KVM_USER_MEM_SLOTS 320 > > #ifdef CONFIG_KVM_MMIO > #define KVM_COALESCED_MMIO_PAGE_OFFSET 1 > Ping! ... any comments on this one? Thomas