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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-04-02 23:53:53 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-04-02 23:53:53 +0300 |
| commit | b0838b150160f90be0903a38a2ce11d764962752 (patch) | |
| tree | 39c71db2c10e4115c7755142b0444191f32b9c07 /drivers | |
| parent | 1d514333da19410751c195cc715f9dbe1bb4b08f (diff) | |
| parent | 3c56b3a12ce52f361468cbdd2f79b2f3b8da0ea6 (diff) | |
| download | linux-b0838b150160f90be0903a38a2ce11d764962752.tar.xz | |
Merge tag 'stable/for-linus-4.0-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen regression fixes from David Vrabel:
"Fix two regressions in the balloon driver's use of memory hotplug when
used in a PV guest"
* tag 'stable/for-linus-4.0-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen/balloon: before adding hotplugged memory, set frames to invalid
x86/xen: prepare p2m list for memory hotplug
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/xen/Kconfig | 17 | ||||
| -rw-r--r-- | drivers/xen/balloon.c | 23 |
2 files changed, 40 insertions, 0 deletions
diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig index b812462083fc..94d96809e686 100644 --- a/drivers/xen/Kconfig +++ b/drivers/xen/Kconfig @@ -55,6 +55,23 @@ config XEN_BALLOON_MEMORY_HOTPLUG In that case step 3 should be omitted. +config XEN_BALLOON_MEMORY_HOTPLUG_LIMIT + int "Hotplugged memory limit (in GiB) for a PV guest" + default 512 if X86_64 + default 4 if X86_32 + range 0 64 if X86_32 + depends on XEN_HAVE_PVMMU + depends on XEN_BALLOON_MEMORY_HOTPLUG + help + Maxmium amount of memory (in GiB) that a PV guest can be + expanded to when using memory hotplug. + + A PV guest can have more memory than this limit if is + started with a larger maximum. + + This value is used to allocate enough space in internal + tables needed for physical memory administration. + config XEN_SCRUB_PAGES bool "Scrub pages before returning them to system" depends on XEN_BALLOON diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c index 0b52d92cb2e5..fd933695f232 100644 --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -229,6 +229,29 @@ static enum bp_state reserve_additional_memory(long credit) balloon_hotplug = round_up(balloon_hotplug, PAGES_PER_SECTION); nid = memory_add_physaddr_to_nid(hotplug_start_paddr); +#ifdef CONFIG_XEN_HAVE_PVMMU + /* + * add_memory() will build page tables for the new memory so + * the p2m must contain invalid entries so the correct + * non-present PTEs will be written. + * + * If a failure occurs, the original (identity) p2m entries + * are not restored since this region is now known not to + * conflict with any devices. + */ + if (!xen_feature(XENFEAT_auto_translated_physmap)) { + unsigned long pfn, i; + + pfn = PFN_DOWN(hotplug_start_paddr); + for (i = 0; i < balloon_hotplug; i++) { + if (!set_phys_to_machine(pfn + i, INVALID_P2M_ENTRY)) { + pr_warn("set_phys_to_machine() failed, no memory added\n"); + return BP_ECANCELED; + } + } + } +#endif + rc = add_memory(nid, hotplug_start_paddr, balloon_hotplug << PAGE_SHIFT); if (rc) { |