* Re: [Xen-devel] [Patch V3 00/15] xen: support pv-domains larger than 512GB [not found] <1429507420-18201-1-git-send-email-jgross@suse.com> @ 2015-05-19 10:11 ` David Vrabel [not found] ` <1429507420-18201-15-git-send-email-jgross@suse.com> 1 sibling, 0 replies; 4+ messages in thread From: David Vrabel @ 2015-05-19 10:11 UTC (permalink / raw) To: Juergen Gross, linux-kernel, xen-devel, konrad.wilk, david.vrabel, boris.ostrovsky On 20/04/15 06:23, Juergen Gross wrote: > Support 64 bit pv-domains with more than 512GB of memory. Reviewed-by: David Vrabel <david.vrabel@citrix.com> I'll try and queue this for 4.2. David ^ permalink raw reply [flat|nested] 4+ messages in thread
[parent not found: <1429507420-18201-15-git-send-email-jgross@suse.com>]
* Re: [Xen-devel] [Patch V3 14/15] xen: allow more than 512 GB of RAM for 64 bit pv-domains [not found] ` <1429507420-18201-15-git-send-email-jgross@suse.com> @ 2015-05-27 16:25 ` David Vrabel 2015-05-27 17:05 ` David Vrabel 0 siblings, 1 reply; 4+ messages in thread From: David Vrabel @ 2015-05-27 16:25 UTC (permalink / raw) To: Juergen Gross, linux-kernel, xen-devel, konrad.wilk, david.vrabel, boris.ostrovsky On 20/04/15 06:23, Juergen Gross wrote: > 64 bit pv-domains under Xen are limited to 512 GB of RAM today. The > main reason has been the 3 level p2m tree, which was replaced by the > virtual mapped linear p2m list. Parallel to the p2m list which is > being used by the kernel itself there is a 3 level mfn tree for usage > by the Xen tools and eventually for crash dump analysis. For this tree > the linear p2m list can serve as a replacement, too. As the kernel > can't know whether the tools are capable of dealing with the p2m list > instead of the mfn tree, the limit of 512 GB can't be dropped in all > cases. > > This patch replaces the hard limit by a kernel parameter which tells > the kernel to obey the 512 GB limit or not. The default is selected by > a configuration parameter which specifies whether the 512 GB limit > should be active per default for domUs (domain save/restore/migration > and crash dump analysis are affected). > > Memory above the domain limit is returned to the hypervisor instead of > being identity mapped, which was wrong anyway. > > The kernel configuration parameter to specify the maximum size of a > domain can be deleted, as it is not relevant any more. Something in this patch breaks the hvc console in my test domU. kernel BUG at /local/davidvr/work/k.org/tip/drivers/tty/hvc/hvc_xen.c:153 Which suggests the hvc driver mapped the wrong console ring frame. David ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [Xen-devel] [Patch V3 14/15] xen: allow more than 512 GB of RAM for 64 bit pv-domains 2015-05-27 16:25 ` [Xen-devel] [Patch V3 14/15] xen: allow more than 512 GB of RAM for 64 bit pv-domains David Vrabel @ 2015-05-27 17:05 ` David Vrabel 2015-06-08 5:09 ` Juergen Gross 0 siblings, 1 reply; 4+ messages in thread From: David Vrabel @ 2015-05-27 17:05 UTC (permalink / raw) To: David Vrabel, Juergen Gross, linux-kernel, xen-devel, konrad.wilk, boris.ostrovsky On 27/05/15 17:25, David Vrabel wrote: > On 20/04/15 06:23, Juergen Gross wrote: >> 64 bit pv-domains under Xen are limited to 512 GB of RAM today. The >> main reason has been the 3 level p2m tree, which was replaced by the >> virtual mapped linear p2m list. Parallel to the p2m list which is >> being used by the kernel itself there is a 3 level mfn tree for usage >> by the Xen tools and eventually for crash dump analysis. For this tree >> the linear p2m list can serve as a replacement, too. As the kernel >> can't know whether the tools are capable of dealing with the p2m list >> instead of the mfn tree, the limit of 512 GB can't be dropped in all >> cases. >> >> This patch replaces the hard limit by a kernel parameter which tells >> the kernel to obey the 512 GB limit or not. The default is selected by >> a configuration parameter which specifies whether the 512 GB limit >> should be active per default for domUs (domain save/restore/migration >> and crash dump analysis are affected). >> >> Memory above the domain limit is returned to the hypervisor instead of >> being identity mapped, which was wrong anyway. >> >> The kernel configuration parameter to specify the maximum size of a >> domain can be deleted, as it is not relevant any more. > > Something in this patch breaks the hvc console in my test domU. > > kernel BUG at /local/davidvr/work/k.org/tip/drivers/tty/hvc/hvc_xen.c:153 > > Which suggests the hvc driver mapped the wrong console ring frame. Sorry, it's patch #13 (xen: move p2m list if conflicting with e820 map) that seems to be bad. David ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [Xen-devel] [Patch V3 14/15] xen: allow more than 512 GB of RAM for 64 bit pv-domains 2015-05-27 17:05 ` David Vrabel @ 2015-06-08 5:09 ` Juergen Gross 0 siblings, 0 replies; 4+ messages in thread From: Juergen Gross @ 2015-06-08 5:09 UTC (permalink / raw) To: David Vrabel, linux-kernel, xen-devel, konrad.wilk, boris.ostrovsky On 05/27/2015 07:05 PM, David Vrabel wrote: > On 27/05/15 17:25, David Vrabel wrote: >> On 20/04/15 06:23, Juergen Gross wrote: >>> 64 bit pv-domains under Xen are limited to 512 GB of RAM today. The >>> main reason has been the 3 level p2m tree, which was replaced by the >>> virtual mapped linear p2m list. Parallel to the p2m list which is >>> being used by the kernel itself there is a 3 level mfn tree for usage >>> by the Xen tools and eventually for crash dump analysis. For this tree >>> the linear p2m list can serve as a replacement, too. As the kernel >>> can't know whether the tools are capable of dealing with the p2m list >>> instead of the mfn tree, the limit of 512 GB can't be dropped in all >>> cases. >>> >>> This patch replaces the hard limit by a kernel parameter which tells >>> the kernel to obey the 512 GB limit or not. The default is selected by >>> a configuration parameter which specifies whether the 512 GB limit >>> should be active per default for domUs (domain save/restore/migration >>> and crash dump analysis are affected). >>> >>> Memory above the domain limit is returned to the hypervisor instead of >>> being identity mapped, which was wrong anyway. >>> >>> The kernel configuration parameter to specify the maximum size of a >>> domain can be deleted, as it is not relevant any more. >> >> Something in this patch breaks the hvc console in my test domU. >> >> kernel BUG at /local/davidvr/work/k.org/tip/drivers/tty/hvc/hvc_xen.c:153 >> >> Which suggests the hvc driver mapped the wrong console ring frame. > > Sorry, it's patch #13 (xen: move p2m list if conflicting with e820 map) > that seems to be bad. I think I've found the reason: the console frame isn't being marked as "reserved" any more. With moving the p2m list I had to change the call of memblock_reserve() for it. Before that patch this call covered the p2m list, the start_info page, the xenstore page and the console page. I added a memblock_reserve() for start_info, but failed to do so for xenstore and console. I'll modify the patch and respin. I have to check why I didn't hit this issue. Maybe my test machine was too large and the memory in question didn't get reused until my test was finished. Thanks for testing, Juergen ^ permalink raw reply [flat|nested] 4+ messages in thread
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2015-05-19 10:11 ` [Xen-devel] [Patch V3 00/15] xen: support pv-domains larger than 512GB David Vrabel
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2015-05-27 16:25 ` [Xen-devel] [Patch V3 14/15] xen: allow more than 512 GB of RAM for 64 bit pv-domains David Vrabel
2015-05-27 17:05 ` David Vrabel
2015-06-08 5:09 ` Juergen Gross
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