From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoffer Dall Subject: Re: [PATCH V2 2/2] KVM: arm64: Increase number of user memslots to 508 Date: Thu, 2 Mar 2017 13:29:06 +0100 Message-ID: <20170302122906.GJ1409@cbox> References: <1486538141-30627-1-git-send-email-linucherian@gmail.com> <1486538141-30627-3-git-send-email-linucherian@gmail.com> <20170223101407.GB1409@cbox> 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 C7A5B40A80 for ; Thu, 2 Mar 2017 07:28:14 -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 x7k9wgUrJ33J for ; Thu, 2 Mar 2017 07:28:12 -0500 (EST) Received: from mail-wr0-f179.google.com (mail-wr0-f179.google.com [209.85.128.179]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id A24EA40966 for ; Thu, 2 Mar 2017 07:28:12 -0500 (EST) Received: by mail-wr0-f179.google.com with SMTP id u48so50945229wrc.0 for ; Thu, 02 Mar 2017 04:29:25 -0800 (PST) Content-Disposition: inline In-Reply-To: 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: Linu Cherian Cc: sunil.goutham@cavium.com, Marc Zyngier , Linu Cherian , pbonzini@redhat.com, kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org List-Id: kvmarm@lists.cs.columbia.edu On Sun, Feb 26, 2017 at 12:36:58PM +0530, Linu Cherian wrote: > On Thu, Feb 23, 2017 at 3:44 PM, Christoffer Dall wrote: > > On Wed, Feb 08, 2017 at 12:45:41PM +0530, 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. > >> > >> Hence increase KVM_USER_MEM_SLOTS to 508, so that KVM_MEM_SLOTS_NUM is > >> 512 as done in other archs like x86 and powerpc. > > > > Actually on powerpc they just define KVM_USER_MEM_SLOTS as 512 directly. > > > > On x86 they define them as 509 and have 3 private mem slots. > > > > I don't understand the difference and as far as I can tell we don't have > > any private memslots on arm/arm64, so this is just weird to me. > > > > Since the KVM_PRIVATE_MEM_SLOTS was already defined as 4, just kept > it untouched. Should we remove this and keep KVM_USER_MEM_SLOTS as 512 ? Do we have any use for KVM_PRIVATE_MEM_SLOTSA being 4? I can't seem to see this. I think we should either get rid of the definition or at least make sure we understand why we're doing things this way. Thanks, -Christoffer From mboxrd@z Thu Jan 1 00:00:00 1970 From: cdall@linaro.org (Christoffer Dall) Date: Thu, 2 Mar 2017 13:29:06 +0100 Subject: [PATCH V2 2/2] KVM: arm64: Increase number of user memslots to 508 In-Reply-To: References: <1486538141-30627-1-git-send-email-linucherian@gmail.com> <1486538141-30627-3-git-send-email-linucherian@gmail.com> <20170223101407.GB1409@cbox> Message-ID: <20170302122906.GJ1409@cbox> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Sun, Feb 26, 2017 at 12:36:58PM +0530, Linu Cherian wrote: > On Thu, Feb 23, 2017 at 3:44 PM, Christoffer Dall wrote: > > On Wed, Feb 08, 2017 at 12:45:41PM +0530, 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. > >> > >> Hence increase KVM_USER_MEM_SLOTS to 508, so that KVM_MEM_SLOTS_NUM is > >> 512 as done in other archs like x86 and powerpc. > > > > Actually on powerpc they just define KVM_USER_MEM_SLOTS as 512 directly. > > > > On x86 they define them as 509 and have 3 private mem slots. > > > > I don't understand the difference and as far as I can tell we don't have > > any private memslots on arm/arm64, so this is just weird to me. > > > > Since the KVM_PRIVATE_MEM_SLOTS was already defined as 4, just kept > it untouched. Should we remove this and keep KVM_USER_MEM_SLOTS as 512 ? Do we have any use for KVM_PRIVATE_MEM_SLOTSA being 4? I can't seem to see this. I think we should either get rid of the definition or at least make sure we understand why we're doing things this way. Thanks, -Christoffer