From c70727a5bc18a5a233fddc6056d1de9144d7a293 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Fri, 17 Jul 2015 06:51:36 +0200 Subject: xen: allow more than 512 GB of RAM for 64 bit pv-domains 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. Signed-off-by: Juergen Gross Acked-by: Konrad Rzeszutek Wilk Signed-off-by: David Vrabel --- Documentation/kernel-parameters.txt | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'Documentation') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 1d6f0459cd7b..47f7b985f833 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -4078,6 +4078,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted. plus one apbt timer for broadcast timer. x86_intel_mid_timer=apbt_only | lapic_and_apbt + xen_512gb_limit [KNL,X86-64,XEN] + Restricts the kernel running paravirtualized under Xen + to use only up to 512 GB of RAM. The reason to do so is + crash analysis tools and Xen tools for doing domain + save/restore/migration must be enabled to handle larger + domains. + xen_emul_unplug= [HW,X86,XEN] Unplug Xen emulated devices Format: [unplug0,][unplug1] -- cgit From 5f141548824cebbff2e838ff401c34e667797467 Mon Sep 17 00:00:00 2001 From: Boris Ostrovsky Date: Mon, 10 Aug 2015 16:34:33 -0400 Subject: xen/PMU: Sysfs interface for setting Xen PMU mode Set Xen's PMU mode via /sys/hypervisor/pmu/pmu_mode. Add XENPMU hypercall. Signed-off-by: Boris Ostrovsky Reviewed-by: Konrad Rzeszutek Wilk Signed-off-by: David Vrabel --- Documentation/ABI/testing/sysfs-hypervisor-pmu | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-hypervisor-pmu (limited to 'Documentation') diff --git a/Documentation/ABI/testing/sysfs-hypervisor-pmu b/Documentation/ABI/testing/sysfs-hypervisor-pmu new file mode 100644 index 000000000000..224faa105e18 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-hypervisor-pmu @@ -0,0 +1,23 @@ +What: /sys/hypervisor/pmu/pmu_mode +Date: August 2015 +KernelVersion: 4.3 +Contact: Boris Ostrovsky +Description: + Describes mode that Xen's performance-monitoring unit (PMU) + uses. Accepted values are + "off" -- PMU is disabled + "self" -- The guest can profile itself + "hv" -- The guest can profile itself and, if it is + privileged (e.g. dom0), the hypervisor + "all" -- The guest can profile itself, the hypervisor + and all other guests. Only available to + privileged guests. + +What: /sys/hypervisor/pmu/pmu_features +Date: August 2015 +KernelVersion: 4.3 +Contact: Boris Ostrovsky +Description: + Describes Xen PMU features (as an integer). A set bit indicates + that the corresponding feature is enabled. See + include/xen/interface/xenpmu.h for available features -- cgit