From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Zyngier Subject: Re: [PATCH] KVM: arm64: Increase number of memslots to 512 Date: Fri, 13 Jan 2017 12:03:38 +0000 Message-ID: <61fa02f8-b244-6bae-eaa1-cb745ea543e1@arm.com> References: <1484153537-20984-1-git-send-email-linucherian@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 881BA40674 for ; Fri, 13 Jan 2017 07:01:56 -0500 (EST) Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Yl-WB3aunFMt for ; Fri, 13 Jan 2017 07:01:55 -0500 (EST) Received: from foss.arm.com (foss.arm.com [217.140.101.70]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 66254402EF for ; Fri, 13 Jan 2017 07:01:54 -0500 (EST) In-Reply-To: <1484153537-20984-1-git-send-email-linucherian@gmail.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu To: linucherian@gmail.com, christoffer.dall@linaro.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, pbonzini@redhat.com, rkrcmar@redhat.com Cc: sunil.goutham@cavium.com, Linu Cherian List-Id: kvmarm@lists.cs.columbia.edu Hi Linu, On 11/01/17 16:52, linucherian@gmail.com wrote: > From: Linu Cherian > > 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 > --- > 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; > case KVM_CAP_MSI_DEVID: > if (!kvm) > r = -EINVAL; > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h > index e505038..88f017d 100644 > --- a/arch/arm64/include/asm/kvm_host.h > +++ b/arch/arm64/include/asm/kvm_host.h > @@ -30,7 +30,7 @@ > > #define __KVM_HAVE_ARCH_INTC_INITIALIZED > > -#define KVM_USER_MEM_SLOTS 32 > +#define KVM_USER_MEM_SLOTS 508 > #define KVM_PRIVATE_MEM_SLOTS 4 > #define KVM_COALESCED_MMIO_PAGE_OFFSET 1 > #define KVM_HALT_POLL_NS_DEFAULT 500000 > I'm not opposed to that patch, but if I may ask: how has that been tested? Thanks, M. -- Jazz is not dead. It just smells funny... From mboxrd@z Thu Jan 1 00:00:00 1970 From: marc.zyngier@arm.com (Marc Zyngier) Date: Fri, 13 Jan 2017 12:03:38 +0000 Subject: [PATCH] KVM: arm64: Increase number of memslots to 512 In-Reply-To: <1484153537-20984-1-git-send-email-linucherian@gmail.com> References: <1484153537-20984-1-git-send-email-linucherian@gmail.com> Message-ID: <61fa02f8-b244-6bae-eaa1-cb745ea543e1@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Linu, On 11/01/17 16:52, linucherian at gmail.com wrote: > From: Linu Cherian > > 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 > --- > 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; > case KVM_CAP_MSI_DEVID: > if (!kvm) > r = -EINVAL; > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h > index e505038..88f017d 100644 > --- a/arch/arm64/include/asm/kvm_host.h > +++ b/arch/arm64/include/asm/kvm_host.h > @@ -30,7 +30,7 @@ > > #define __KVM_HAVE_ARCH_INTC_INITIALIZED > > -#define KVM_USER_MEM_SLOTS 32 > +#define KVM_USER_MEM_SLOTS 508 > #define KVM_PRIVATE_MEM_SLOTS 4 > #define KVM_COALESCED_MMIO_PAGE_OFFSET 1 > #define KVM_HALT_POLL_NS_DEFAULT 500000 > I'm not opposed to that patch, but if I may ask: how has that been tested? Thanks, M. -- Jazz is not dead. It just smells funny...