I wanted to run without 2MB and 1GB EPT pages, so I added "hap_2mb=0 hap_1gb=0" to the Xen grub command line. However I see the following on Xen boot: (XEN) EPT supports 2MB super page. When I bring up a guest I see a non-zero number of 2MB pages in the "xl create" output: xc: info: VIRTUAL MEMORY ARRANGEMENT: Loader: 0000000000100000->000000000017af10 TOTAL: 0000000000000000->000000001f000000 ENTRY ADDRESS: 00000000001015a0 xc: info: PHYSICAL MEMORY ALLOCATION: 4KB PAGES: 0x0000000000000200 2MB PAGES: 0x00000000000000f7 1GB PAGES: 0x0000000000000000 Daemon running with PID 2867 Have I added the options in the right place? Do I need to do anything else to disable super pages? Thanks, AP
On 08/03/2012 00:36, "AP" <apxeng@gmail.com> wrote:> I wanted to run without 2MB and 1GB EPT pages, so I added "hap_2mb=0 > hap_1gb=0" to the Xen grub command line. However I see the following > on Xen boot: > > (XEN) EPT supports 2MB super page.This simply indicates the CPU supports this feature, regardless of whether Xen is configured to use it.> When I bring up a guest I see a non-zero number of 2MB pages in the > "xl create" output: > > xc: info: VIRTUAL MEMORY ARRANGEMENT: > Loader: 0000000000100000->000000000017af10 > TOTAL: 0000000000000000->000000001f000000 > ENTRY ADDRESS: 00000000001015a0 > xc: info: PHYSICAL MEMORY ALLOCATION: > 4KB PAGES: 0x0000000000000200 > 2MB PAGES: 0x00000000000000f7 > 1GB PAGES: 0x0000000000000000 > Daemon running with PID 2867This simply indicates that the HVM domain builder managed to allocate that number of 2MB extents of memory. It does not necessarily mean that those 2MB extents will be mapped into guest address space with 2MB superpage mappings.> Have I added the options in the right place? Do I need to do anything > else to disable super pages?Unfortunately there is no logging output that indicates that the hap_2mb/hap_1gb=0 options are working. You have set the options correctly. I will sort out a small patch for this. -- Keir> Thanks, > AP > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xen.org > http://lists.xen.org/xen-devel
On 08/03/2012 06:11, "Keir Fraser" <keir.xen@gmail.com> wrote:>> Have I added the options in the right place? Do I need to do anything >> else to disable super pages? > > Unfortunately there is no logging output that indicates that the > hap_2mb/hap_1gb=0 options are working. You have set the options correctly. > > I will sort out a small patch for this.Done as xen_unstable:24992. I removed the VMX-specific "EPT supports XX super page" lines, and replaced with a single line of the form (for example): HVM: HAP page sizes: 4kB, 2MB [disabled], 1GB [disabled] The ''[disabled]'' bit corresponds to setting hap_2mb/1gb=0. -- Keir> -- Keir > >> Thanks, >> AP >> >> _______________________________________________ >> Xen-devel mailing list >> Xen-devel@lists.xen.org >> http://lists.xen.org/xen-devel > >
On Thu, Mar 8, 2012 at 1:47 AM, Keir Fraser <keir@xen.org> wrote:> On 08/03/2012 06:11, "Keir Fraser" <keir.xen@gmail.com> wrote: > >>> Have I added the options in the right place? Do I need to do anything >>> else to disable super pages? >> >> Unfortunately there is no logging output that indicates that the >> hap_2mb/hap_1gb=0 options are working. You have set the options correctly. >> >> I will sort out a small patch for this. > > Done as xen_unstable:24992. I removed the VMX-specific "EPT supports XX > super page" lines, and replaced with a single line of the form (for > example): > HVM: HAP page sizes: 4kB, 2MB [disabled], 1GB [disabled] > > The ''[disabled]'' bit corresponds to setting hap_2mb/1gb=0.Thank you. This is very helpful. I realize that this is just an info output patch albeit a useful one. So any chance of having this considered for a backport to Xen 4.1.x? AP> -- Keir > >> -- Keir >> >>> Thanks, >>> AP >>> >>> _______________________________________________ >>> Xen-devel mailing list >>> Xen-devel@lists.xen.org >>> http://lists.xen.org/xen-devel >> >> > >
On 08/03/2012 19:38, "AP" <apxeng@gmail.com> wrote:> On Thu, Mar 8, 2012 at 1:47 AM, Keir Fraser <keir@xen.org> wrote: >> On 08/03/2012 06:11, "Keir Fraser" <keir.xen@gmail.com> wrote: >> >>>> Have I added the options in the right place? Do I need to do anything >>>> else to disable super pages? >>> >>> Unfortunately there is no logging output that indicates that the >>> hap_2mb/hap_1gb=0 options are working. You have set the options correctly. >>> >>> I will sort out a small patch for this. >> >> Done as xen_unstable:24992. I removed the VMX-specific "EPT supports XX >> super page" lines, and replaced with a single line of the form (for >> example): >> HVM: HAP page sizes: 4kB, 2MB [disabled], 1GB [disabled] >> >> The ''[disabled]'' bit corresponds to setting hap_2mb/1gb=0. > > Thank you. This is very helpful. I realize that this is just an info > output patch albeit a useful one. So any chance of having this > considered for a backport to Xen 4.1.x?Yes, should be easy to do. -- Keir> AP > >> -- Keir >> >>> -- Keir >>> >>>> Thanks, >>>> AP >>>> >>>> _______________________________________________ >>>> Xen-devel mailing list >>>> Xen-devel@lists.xen.org >>>> http://lists.xen.org/xen-devel >>> >>> >> >>
On 08/03/2012 19:38, "AP" <apxeng@gmail.com> wrote:> On Thu, Mar 8, 2012 at 1:47 AM, Keir Fraser <keir@xen.org> wrote: >> On 08/03/2012 06:11, "Keir Fraser" <keir.xen@gmail.com> wrote: >> >>>> Have I added the options in the right place? Do I need to do anything >>>> else to disable super pages? >>> >>> Unfortunately there is no logging output that indicates that the >>> hap_2mb/hap_1gb=0 options are working. You have set the options correctly. >>> >>> I will sort out a small patch for this. >> >> Done as xen_unstable:24992. I removed the VMX-specific "EPT supports XX >> super page" lines, and replaced with a single line of the form (for >> example): >> HVM: HAP page sizes: 4kB, 2MB [disabled], 1GB [disabled] >> >> The ''[disabled]'' bit corresponds to setting hap_2mb/1gb=0. > > Thank you. This is very helpful. I realize that this is just an info > output patch albeit a useful one. So any chance of having this > considered for a backport to Xen 4.1.x?Done, xen-4.1-testing:23264. -- Keir> AP > >> -- Keir >> >>> -- Keir >>> >>>> Thanks, >>>> AP >>>> >>>> _______________________________________________ >>>> Xen-devel mailing list >>>> Xen-devel@lists.xen.org >>>> http://lists.xen.org/xen-devel >>> >>> >> >>