From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lan Tianyu Subject: Re: [RFC PATCH V2 1/26] VIOMMU: Add vIOMMU helper functions to create, destroy and query capabilities Date: Fri, 2 Jun 2017 15:10:27 +0800 Message-ID: <594e6f07-9e42-37d5-5638-2d683452b98f@intel.com> References: <1495085696-10819-1-git-send-email-tianyu.lan@intel.com> <1495085696-10819-2-git-send-email-tianyu.lan@intel.com> <20170530153605.j7qxss2ppvosz2ua@citrix.com> <592DAF08020000780015DCC1@prv-mh.provo.novell.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============9095369025725288722==" Return-path: In-Reply-To: <592DAF08020000780015DCC1@prv-mh.provo.novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xen.org Sender: "Xen-devel" To: Jan Beulich , wei.liu2@citrix.com, julien.grall@arm.com Cc: andrew.cooper3@citrix.com, kevin.tian@intel.com, xen-devel@lists.xen.org, ian.jackson@eu.citrix.com, chao.gao@intel.com List-Id: xen-devel@lists.xenproject.org This is a multi-part message in MIME format. --===============9095369025725288722== Content-Type: multipart/alternative; boundary="------------114FE55BDCCDBA3DF3BC5265" This is a multi-part message in MIME format. --------------114FE55BDCCDBA3DF3BC5265 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Hi Jan: Thanks for your review. On 2017年05月30日 23:42, Jan Beulich wrote: >>>> On 30.05.17 at 17:36, wrote: >> On Thu, May 18, 2017 at 01:34:31AM -0400, Lan Tianyu wrote: >>> --- a/xen/common/Kconfig >>> +++ b/xen/common/Kconfig >>> @@ -73,6 +73,17 @@ config TMEM >>> >>> If unsure, say Y. >>> >>> +config VIOMMU >>> + def_bool y >>> + prompt "Xen vIOMMU Support" if EXPERT = "y" >>> + depends on X86 >>> + ---help--- >>> + Virtual IOMMU provides interrupt remapping function for guest and >>> + it allows guest to boot up more than 255 vcpus which requires interrupt >>> + remapping function. >>> + >>> + If unsure, say Y. >> Indentation. And this should be disabled by default. > It's actually a question whether in our current scheme a Kconfig > option is appropriate here in the first place. I'd rather see this be > an always built feature which needs enabling on the command line > for the time being. In the RFC V1, we made vIOMMU always built-in feature. But ARM or other arches doesn't have vIOMMU support. Julien suggested to introduce a new Kconfig and only built vIOMMU on x86. Both two ways won't affect vIOMMU function. https://www.mail-archive.com/xen-devel@lists.xen.org/msg101421.html Jan & Julien, we need to make a choice here. -- Best regards Tianyu Lan --------------114FE55BDCCDBA3DF3BC5265 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: 8bit

Hi Jan:

          Thanks for your review.


On 2017年05月30日 23:42, Jan Beulich wrote:
On 30.05.17 at 17:36, <wei.liu2@citrix.com> wrote:

On Thu, May 18, 2017 at 01:34:31AM -0400, Lan Tianyu wrote:

--- a/xen/common/Kconfig
+++ b/xen/common/Kconfig
@@ -73,6 +73,17 @@ config TMEM
 
 	  If unsure, say Y.
 
+config VIOMMU
+	def_bool y
+	prompt "Xen vIOMMU Support" if EXPERT = "y"
+	depends on X86
+	---help---
+	 Virtual IOMMU provides interrupt remapping function for guest and
+	 it allows guest to boot up more than 255 vcpus which requires interrupt
+	 remapping function.
+
+	  If unsure, say Y.

Indentation. And this should be disabled by default.

It's actually a question whether in our current scheme a Kconfig
option is appropriate here in the first place. I'd rather see this be
an always built feature which needs enabling on the command line
for the time being.

          In the RFC V1, we made vIOMMU always built-in feature. But ARM or other arches doesn't have vIOMMU support.

Julien suggested to introduce a new Kconfig and only built vIOMMU on x86. Both two ways won't affect vIOMMU function.

https://www.mail-archive.com/xen-devel@lists.xen.org/msg101421.html

Jan & Julien, we need to make a choice here. 

-- 
Best regards
Tianyu Lan
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