diff options
| -rw-r--r-- | Documentation/kernel-parameters.txt | 7 | ||||
| -rw-r--r-- | arch/x86/include/asm/xen/page.h | 4 | ||||
| -rw-r--r-- | arch/x86/xen/Kconfig | 20 | ||||
| -rw-r--r-- | arch/x86/xen/p2m.c | 10 | ||||
| -rw-r--r-- | arch/x86/xen/setup.c | 59 |
5 files changed, 73 insertions, 27 deletions
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] diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h index c44a5d53e464..10ef14b2616d 100644 --- a/arch/x86/include/asm/xen/page.h +++ b/arch/x86/include/asm/xen/page.h @@ -35,10 +35,6 @@ typedef struct xpaddr { #define FOREIGN_FRAME(m) ((m) | FOREIGN_FRAME_BIT) #define IDENTITY_FRAME(m) ((m) | IDENTITY_FRAME_BIT) -/* Maximum amount of memory we can handle in a domain in pages */ -#define MAX_DOMAIN_PAGES \ - ((unsigned long)((u64)CONFIG_XEN_MAX_DOMAIN_MEMORY * 1024 * 1024 * 1024 / PAGE_SIZE)) - extern unsigned long *machine_to_phys_mapping; extern unsigned long machine_to_phys_nr; extern unsigned long *xen_p2m_addr; diff --git a/arch/x86/xen/Kconfig b/arch/x86/xen/Kconfig index e88fda867a33..7bcf21b865d1 100644 --- a/arch/x86/xen/Kconfig +++ b/arch/x86/xen/Kconfig @@ -23,14 +23,18 @@ config XEN_PVHVM def_bool y depends on XEN && PCI && X86_LOCAL_APIC -config XEN_MAX_DOMAIN_MEMORY - int - default 500 if X86_64 - default 64 if X86_32 - depends on XEN - help - This only affects the sizing of some bss arrays, the unused - portions of which are freed. +config XEN_512GB + bool "Limit Xen pv-domain memory to 512GB" + depends on XEN && X86_64 + default y + help + Limit paravirtualized user domains to 512GB of RAM. + + The Xen tools and crash dump analysis tools might not support + pv-domains with more than 512 GB of RAM. This option controls the + default setting of the kernel to use only up to 512 GB or more. + It is always possible to change the default via specifying the + boot parameter "xen_512gb_limit". config XEN_SAVE_RESTORE bool diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c index c719f7c36cb8..c059ca1c8293 100644 --- a/arch/x86/xen/p2m.c +++ b/arch/x86/xen/p2m.c @@ -517,7 +517,7 @@ static pte_t *alloc_p2m_pmd(unsigned long addr, pte_t *pte_pg) */ static bool alloc_p2m(unsigned long pfn) { - unsigned topidx, mididx; + unsigned topidx; unsigned long *top_mfn_p, *mid_mfn; pte_t *ptep, *pte_pg; unsigned int level; @@ -525,9 +525,6 @@ static bool alloc_p2m(unsigned long pfn) unsigned long addr = (unsigned long)(xen_p2m_addr + pfn); unsigned long p2m_pfn; - topidx = p2m_top_index(pfn); - mididx = p2m_mid_index(pfn); - ptep = lookup_address(addr, &level); BUG_ON(!ptep || level != PG_LEVEL_4K); pte_pg = (pte_t *)((unsigned long)ptep & ~(PAGE_SIZE - 1)); @@ -539,7 +536,8 @@ static bool alloc_p2m(unsigned long pfn) return false; } - if (p2m_top_mfn) { + if (p2m_top_mfn && pfn < MAX_P2M_PFN) { + topidx = p2m_top_index(pfn); top_mfn_p = &p2m_top_mfn[topidx]; mid_mfn = ACCESS_ONCE(p2m_top_mfn_p[topidx]); @@ -596,7 +594,7 @@ static bool alloc_p2m(unsigned long pfn) wmb(); /* Tools are synchronizing via p2m_generation. */ HYPERVISOR_shared_info->arch.p2m_generation++; if (mid_mfn) - mid_mfn[mididx] = virt_to_mfn(p2m); + mid_mfn[p2m_mid_index(pfn)] = virt_to_mfn(p2m); p2m = NULL; } diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c index b096d02d34ac..f96002107691 100644 --- a/arch/x86/xen/setup.c +++ b/arch/x86/xen/setup.c @@ -33,6 +33,8 @@ #include "p2m.h" #include "mmu.h" +#define GB(x) ((uint64_t)(x) * 1024 * 1024 * 1024) + /* Amount of extra memory space we add to the e820 ranges */ struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata; @@ -69,6 +71,26 @@ static unsigned long xen_remap_mfn __initdata = INVALID_P2M_ENTRY; */ #define EXTRA_MEM_RATIO (10) +static bool xen_512gb_limit __initdata = IS_ENABLED(CONFIG_XEN_512GB); + +static void __init xen_parse_512gb(void) +{ + bool val = false; + char *arg; + + arg = strstr(xen_start_info->cmd_line, "xen_512gb_limit"); + if (!arg) + return; + + arg = strstr(xen_start_info->cmd_line, "xen_512gb_limit="); + if (!arg) + val = true; + else if (strtobool(arg + strlen("xen_512gb_limit="), &val)) + return; + + xen_512gb_limit = val; +} + static void __init xen_add_extra_mem(phys_addr_t start, phys_addr_t size) { int i; @@ -503,12 +525,29 @@ void __init xen_remap_memory(void) pr_info("Remapped %ld page(s)\n", remapped); } +static unsigned long __init xen_get_pages_limit(void) +{ + unsigned long limit; + +#ifdef CONFIG_X86_32 + limit = GB(64) / PAGE_SIZE; +#else + limit = ~0ul; + if (!xen_initial_domain() && xen_512gb_limit) + limit = GB(512) / PAGE_SIZE; +#endif + return limit; +} + static unsigned long __init xen_get_max_pages(void) { - unsigned long max_pages = MAX_DOMAIN_PAGES; + unsigned long max_pages, limit; domid_t domid = DOMID_SELF; int ret; + limit = xen_get_pages_limit(); + max_pages = limit; + /* * For the initial domain we use the maximum reservation as * the maximum page. @@ -524,7 +563,7 @@ static unsigned long __init xen_get_max_pages(void) max_pages = ret; } - return min(max_pages, MAX_DOMAIN_PAGES); + return min(max_pages, limit); } static void __init xen_align_and_add_e820_region(phys_addr_t start, @@ -699,7 +738,7 @@ static void __init xen_reserve_xen_mfnlist(void) **/ char * __init xen_memory_setup(void) { - unsigned long max_pfn = xen_start_info->nr_pages; + unsigned long max_pfn; phys_addr_t mem_end, addr, size, chunk_size; u32 type; int rc; @@ -709,7 +748,9 @@ char * __init xen_memory_setup(void) int i; int op; - max_pfn = min(MAX_DOMAIN_PAGES, max_pfn); + xen_parse_512gb(); + max_pfn = xen_get_pages_limit(); + max_pfn = min(max_pfn, xen_start_info->nr_pages); mem_end = PFN_PHYS(max_pfn); memmap.nr_entries = E820MAX; @@ -762,12 +803,15 @@ char * __init xen_memory_setup(void) * is limited to the max size of lowmem, so that it doesn't * get completely filled. * + * Make sure we have no memory above max_pages, as this area + * isn't handled by the p2m management. + * * In principle there could be a problem in lowmem systems if * the initial memory is also very large with respect to * lowmem, but we won't try to deal with that here. */ - extra_pages = min(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)), - extra_pages); + extra_pages = min3(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)), + extra_pages, max_pages - max_pfn); i = 0; addr = xen_e820_map[0].addr; size = xen_e820_map[0].size; @@ -803,9 +847,6 @@ char * __init xen_memory_setup(void) /* * Set the rest as identity mapped, in case PCI BARs are * located here. - * - * PFNs above MAX_P2M_PFN are considered identity mapped as - * well. */ set_phys_range_identity(addr / PAGE_SIZE, ~0ul); |