From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kai Huang Subject: Re: [v2 02/11] doc: add description for new PML boot parameter Date: Thu, 16 Apr 2015 12:47:50 +0800 Message-ID: <552F3EF6.9050709@linux.intel.com> References: <1429081433-9600-1-git-send-email-kai.huang@linux.intel.com> <1429081433-9600-3-git-send-email-kai.huang@linux.intel.com> <552E3A48.9040107@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <552E3A48.9040107@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Andrew Cooper , tim@xen.org, jbeulich@suse.com, kevin.tian@intel.com, xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org On 04/15/2015 06:15 PM, Andrew Cooper wrote: > On 15/04/15 08:03, Kai Huang wrote: >> This patch adds doc description for new boot parameter 'ept=pml'. >> >> Signed-off-by: Kai Huang > Personally, I would fold this patch into the previous so the > documentation is in the same patch as introduces the parameter. Thanks for suggestion. Will do in the next version. > >> --- >> docs/misc/xen-command-line.markdown | 14 ++++++++++++++ >> 1 file changed, 14 insertions(+) >> >> diff --git a/docs/misc/xen-command-line.markdown b/docs/misc/xen-command-line.markdown >> index 1dda1f0..ae30d02 100644 >> --- a/docs/misc/xen-command-line.markdown >> +++ b/docs/misc/xen-command-line.markdown >> @@ -685,6 +685,20 @@ requirement can be relaxed. This option is particularly useful for nested >> virtualization, to allow the L1 hypervisor to use EPT even if the L0 hypervisor >> does not provide VM\_ENTRY\_LOAD\_GUEST\_PAT. >> >> +### ept (Intel) >> +> `= List of [ pml ]` >> + >> +> Sub-options: >> + >> +> `pml` >> + >> +> This sub-option is boolean type and can be prefixed with `no-` to effect the >> +> inverse meaning. >> + >> +> Default: `false` >> + >> +>> Control the use of Page Modification Logging for log-dirty. > Can you follow the same style as the "psr" option? Specifically, I > don't think you need to re-describe what a boolean parameter is. Thanks for suggestion. I chose to follow the "iommu=" style parameter as to me the "ept=" parameter is more likely to the "iommu=" parameter -- both of them intend to have various sub-boolean types, within which some may or may not be independent to each other. Referring to 'psr' parameter, does below change look good to you? +### ept (Intel) +> `= List of ( pml )` + +> Default: `false` + +Controls EPT related features. Currently only Page Modification Logging (PML) is +the controllable feature as boolean type. + +PML is a new hardware feature in Intel's Broadwell Server and further platforms +which reduces hypervisor overhead of log-dirty mechanism by automatically +recording GPAs (guest physical addresses) when guest memory gets dirty, and +therefore significantly reducing number of EPT violation caused by write +protection of guest memory, which is a necessity to implement log-dirty +mechanism before PML. Thanks, -Kai > > ~Andrew > >> + >> ### gdb >> > `= [/][,DPS[,[,[,[,]]]] | pci | amt ] ` >> > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xen.org > http://lists.xen.org/xen-devel