From 7a89df28ceebe28c68a57a8a4e41e7b3183d6197 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Fri, 17 Jul 2015 06:51:34 +0200 Subject: [PATCH] xen: add explicit memblock_reserve() calls for special pages Some special pages containing interfaces to xen are being reserved implicitly only today. The memblock_reserve() call to reserve them is meant to reserve the p2m list supplied by xen. It is just reserving not only the p2m list itself, but some more pages up to the start of the xen built page tables. To be able to move the p2m list to another pfn range, which is needed for support of huge RAM, this memblock_reserve() must be split up to cover all affected reserved pages explicitly. The affected pages are: - start_info page - xenstore ring (might be missing, mfn is 0 in this case) - console ring (not for initial domain) Signed-off-by: Juergen Gross Signed-off-by: David Vrabel (cherry picked from commit 6c2681c863b24360098d1ba60f2af060a13a0561) Signed-off-by: Konrad Rzeszutek Wilk (cherry picked from commit f9918f852bb0e2cd1e7a86966e5f3d0dd25a094f) --- arch/x86/xen/enlighten.c | 4 +++- arch/x86/xen/mmu.c | 15 +++++++++++++++ arch/x86/xen/xen-ops.h | 1 + 3 files changed, 19 insertions(+), 1 deletion(-) diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 187dec64d5b5..b3b5c22a2c8f 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -1579,7 +1579,9 @@ asmlinkage __visible void __init xen_start_kernel(void) early_boot_irqs_disabled = true; xen_raw_console_write("mapping kernel into physical memory\n"); - xen_setup_kernel_pagetable((pgd_t *)xen_start_info->pt_base, xen_start_info->nr_pages); + xen_setup_kernel_pagetable((pgd_t *)xen_start_info->pt_base, + xen_start_info->nr_pages); + xen_reserve_special_pages(); /* * Modify the cache mode translation tables to match Xen's PAT diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index 1982617fa9c7..a36e7b462640 100644 --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -2084,6 +2084,21 @@ void __init xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn) } #endif /* CONFIG_X86_64 */ +void __init xen_reserve_special_pages(void) +{ + phys_addr_t paddr; + + memblock_reserve(__pa(xen_start_info), PAGE_SIZE); + if (xen_start_info->store_mfn) { + paddr = PFN_PHYS(mfn_to_pfn(xen_start_info->store_mfn)); + memblock_reserve(paddr, PAGE_SIZE); + } + if (!xen_initial_domain()) { + paddr = PFN_PHYS(mfn_to_pfn(xen_start_info->console.domU.mfn)); + memblock_reserve(paddr, PAGE_SIZE); + } +} + void __init xen_pt_check_e820(void) { if (xen_is_e820_reserved(xen_pt_base, xen_pt_size)) { diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h index c47378e07018..8a3338f34e14 100644 --- a/arch/x86/xen/xen-ops.h +++ b/arch/x86/xen/xen-ops.h @@ -35,6 +35,7 @@ void xen_build_mfn_list_list(void); void xen_setup_machphys_mapping(void); void xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn); void xen_reserve_top(void); +void __init xen_reserve_special_pages(void); void __init xen_pt_check_e820(void); void xen_mm_pin_all(void); -- 2.50.1