| Message ID | 20190214104240.24428-3-jgross@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | x86: respect memory size limits | expand |
On 2/14/19 5:42 AM, Juergen Gross wrote: > Don't allow memory to be added above the allowed maximum allocation > limit set by Xen. > > Trying to do so would result in cases like the following: > > [ 584.559652] ------------[ cut here ]------------ > [ 584.564897] WARNING: CPU: 2 PID: 1 at ../arch/x86/xen/multicalls.c:129 xen_alloc_pte+0x1c7/0x390() > [ 584.575151] Modules linked in: > [ 584.578643] Supported: Yes > [ 584.581750] CPU: 2 PID: 1 Comm: swapper/0 Not tainted 4.4.120-92.70-default #1 > [ 584.590000] Hardware name: Cisco Systems Inc UCSC-C460-M4/UCSC-C460-M4, BIOS C460M4.4.0.1b.0.0629181419 06/29/2018 > [ 584.601862] 0000000000000000 ffffffff813175a0 0000000000000000 ffffffff8184777c > [ 584.610200] ffffffff8107f4e1 ffff880487eb7000 ffff8801862b79c0 ffff88048608d290 > [ 584.618537] 0000000000487eb7 ffffea0000000201 ffffffff81009de7 ffffffff81068561 > [ 584.626876] Call Trace: > [ 584.629699] [<ffffffff81019ad9>] dump_trace+0x59/0x340 > [ 584.635645] [<ffffffff81019eaa>] show_stack_log_lvl+0xea/0x170 > [ 584.642391] [<ffffffff8101ac51>] show_stack+0x21/0x40 > [ 584.648238] [<ffffffff813175a0>] dump_stack+0x5c/0x7c > [ 584.654085] [<ffffffff8107f4e1>] warn_slowpath_common+0x81/0xb0 > [ 584.660932] [<ffffffff81009de7>] xen_alloc_pte+0x1c7/0x390 > [ 584.667289] [<ffffffff810647f0>] pmd_populate_kernel.constprop.6+0x40/0x80 > [ 584.675241] [<ffffffff815ecfe8>] phys_pmd_init+0x210/0x255 > [ 584.681587] [<ffffffff815ed207>] phys_pud_init+0x1da/0x247 > [ 584.687931] [<ffffffff815edb3b>] kernel_physical_mapping_init+0xf5/0x1d4 > [ 584.695682] [<ffffffff815e9bdd>] init_memory_mapping+0x18d/0x380 > [ 584.702631] [<ffffffff81064699>] arch_add_memory+0x59/0xf0 > > Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c index d5f303c0e656..0e770f5e5e8c 100644 --- a/arch/x86/xen/setup.c +++ b/arch/x86/xen/setup.c @@ -12,6 +12,7 @@ #include <linux/memblock.h> #include <linux/cpuidle.h> #include <linux/cpufreq.h> +#include <linux/memory_hotplug.h> #include <asm/elf.h> #include <asm/vdso.h> @@ -589,6 +590,14 @@ static void __init xen_align_and_add_e820_region(phys_addr_t start, if (type == E820_TYPE_RAM) { start = PAGE_ALIGN(start); end &= ~((phys_addr_t)PAGE_SIZE - 1); +#ifdef CONFIG_MEMORY_HOTPLUG + /* + * Don't allow adding memory not in E820 map while booting the + * system. Once the balloon driver is up it will remove that + * restriction again. + */ + max_mem_size = end; +#endif } e820__range_add(start, end - start, type); @@ -748,6 +757,10 @@ char * __init xen_memory_setup(void) memmap.nr_entries = ARRAY_SIZE(xen_e820_table.entries); set_xen_guest_handle(memmap.buffer, xen_e820_table.entries); +#ifdef CONFIG_MEMORY_HOTPLUG + xen_saved_max_mem_size = max_mem_size; +#endif + op = xen_initial_domain() ? XENMEM_machine_memory_map : XENMEM_memory_map; diff --git a/drivers/xen/xen-balloon.c b/drivers/xen/xen-balloon.c index 2acbfe104e46..a67236b02452 100644 --- a/drivers/xen/xen-balloon.c +++ b/drivers/xen/xen-balloon.c @@ -37,6 +37,7 @@ #include <linux/mm_types.h> #include <linux/init.h> #include <linux/capability.h> +#include <linux/memory_hotplug.h> #include <xen/xen.h> #include <xen/interface/xen.h> @@ -50,6 +51,10 @@ #define BALLOON_CLASS_NAME "xen_memory" +#ifdef CONFIG_MEMORY_HOTPLUG +u64 xen_saved_max_mem_size = 0; +#endif + static struct device balloon_dev; static int register_balloon(struct device *dev); @@ -63,6 +68,12 @@ static void watch_target(struct xenbus_watch *watch, static bool watch_fired; static long target_diff; +#ifdef CONFIG_MEMORY_HOTPLUG + /* The balloon driver will take care of adding memory now. */ + if (xen_saved_max_mem_size) + max_mem_size = xen_saved_max_mem_size; +#endif + err = xenbus_scanf(XBT_NIL, "memory", "target", "%llu", &new_target); if (err != 1) { /* This is ok (for domain0 at least) - so just return */ diff --git a/include/xen/xen.h b/include/xen/xen.h index 0e2156786ad2..d8f1ab43ab56 100644 --- a/include/xen/xen.h +++ b/include/xen/xen.h @@ -46,4 +46,8 @@ struct bio_vec; bool xen_biovec_phys_mergeable(const struct bio_vec *vec1, const struct bio_vec *vec2); +#ifdef CONFIG_MEMORY_HOTPLUG +extern u64 xen_saved_max_mem_size; +#endif + #endif /* _XEN_XEN_H */
Don't allow memory to be added above the allowed maximum allocation limit set by Xen. Trying to do so would result in cases like the following: [ 584.559652] ------------[ cut here ]------------ [ 584.564897] WARNING: CPU: 2 PID: 1 at ../arch/x86/xen/multicalls.c:129 xen_alloc_pte+0x1c7/0x390() [ 584.575151] Modules linked in: [ 584.578643] Supported: Yes [ 584.581750] CPU: 2 PID: 1 Comm: swapper/0 Not tainted 4.4.120-92.70-default #1 [ 584.590000] Hardware name: Cisco Systems Inc UCSC-C460-M4/UCSC-C460-M4, BIOS C460M4.4.0.1b.0.0629181419 06/29/2018 [ 584.601862] 0000000000000000 ffffffff813175a0 0000000000000000 ffffffff8184777c [ 584.610200] ffffffff8107f4e1 ffff880487eb7000 ffff8801862b79c0 ffff88048608d290 [ 584.618537] 0000000000487eb7 ffffea0000000201 ffffffff81009de7 ffffffff81068561 [ 584.626876] Call Trace: [ 584.629699] [<ffffffff81019ad9>] dump_trace+0x59/0x340 [ 584.635645] [<ffffffff81019eaa>] show_stack_log_lvl+0xea/0x170 [ 584.642391] [<ffffffff8101ac51>] show_stack+0x21/0x40 [ 584.648238] [<ffffffff813175a0>] dump_stack+0x5c/0x7c [ 584.654085] [<ffffffff8107f4e1>] warn_slowpath_common+0x81/0xb0 [ 584.660932] [<ffffffff81009de7>] xen_alloc_pte+0x1c7/0x390 [ 584.667289] [<ffffffff810647f0>] pmd_populate_kernel.constprop.6+0x40/0x80 [ 584.675241] [<ffffffff815ecfe8>] phys_pmd_init+0x210/0x255 [ 584.681587] [<ffffffff815ed207>] phys_pud_init+0x1da/0x247 [ 584.687931] [<ffffffff815edb3b>] kernel_physical_mapping_init+0xf5/0x1d4 [ 584.695682] [<ffffffff815e9bdd>] init_memory_mapping+0x18d/0x380 [ 584.702631] [<ffffffff81064699>] arch_add_memory+0x59/0xf0 Signed-off-by: Juergen Gross <jgross@suse.com> --- arch/x86/xen/setup.c | 13 +++++++++++++ drivers/xen/xen-balloon.c | 11 +++++++++++ include/xen/xen.h | 4 ++++ 3 files changed, 28 insertions(+)