From 626d7508664c4bc8e67f496da4387ecd0c410b8c Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Fri, 4 Sep 2015 14:05:51 +0200 Subject: [PATCH] xen: switch extra memory accounting to use pfns MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Instead of using physical addresses for accounting of extra memory areas available for ballooning switch to pfns as this is much less error prone regarding partial pages. Reported-by: Roger Pau Monné Tested-by: Roger Pau Monné Signed-off-by: Juergen Gross Signed-off-by: David Vrabel --- arch/x86/xen/setup.c | 80 ++++++++++++++++++++++++------------------- drivers/xen/balloon.c | 6 ++-- include/xen/page.h | 4 +-- 3 files changed, 49 insertions(+), 41 deletions(-) diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c index 70de4c8b8f27..f5ef6746d47a 100644 --- a/arch/x86/xen/setup.c +++ b/arch/x86/xen/setup.c @@ -90,62 +90,69 @@ static void __init xen_parse_512gb(void) xen_512gb_limit = val; } -static void __init xen_add_extra_mem(phys_addr_t start, phys_addr_t size) +static void __init xen_add_extra_mem(unsigned long start_pfn, + unsigned long n_pfns) { int i; + /* + * No need to check for zero size, should happen rarely and will only + * write a new entry regarded to be unused due to zero size. + */ for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) { /* Add new region. */ - if (xen_extra_mem[i].size == 0) { - xen_extra_mem[i].start = start; - xen_extra_mem[i].size = size; + if (xen_extra_mem[i].n_pfns == 0) { + xen_extra_mem[i].start_pfn = start_pfn; + xen_extra_mem[i].n_pfns = n_pfns; break; } /* Append to existing region. */ - if (xen_extra_mem[i].start + xen_extra_mem[i].size == start) { - xen_extra_mem[i].size += size; + if (xen_extra_mem[i].start_pfn + xen_extra_mem[i].n_pfns == + start_pfn) { + xen_extra_mem[i].n_pfns += n_pfns; break; } } if (i == XEN_EXTRA_MEM_MAX_REGIONS) printk(KERN_WARNING "Warning: not enough extra memory regions\n"); - memblock_reserve(start, size); + memblock_reserve(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns)); } -static void __init xen_del_extra_mem(phys_addr_t start, phys_addr_t size) +static void __init xen_del_extra_mem(unsigned long start_pfn, + unsigned long n_pfns) { int i; - phys_addr_t start_r, size_r; + unsigned long start_r, size_r; for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) { - start_r = xen_extra_mem[i].start; - size_r = xen_extra_mem[i].size; + start_r = xen_extra_mem[i].start_pfn; + size_r = xen_extra_mem[i].n_pfns; /* Start of region. */ - if (start_r == start) { - BUG_ON(size > size_r); - xen_extra_mem[i].start += size; - xen_extra_mem[i].size -= size; + if (start_r == start_pfn) { + BUG_ON(n_pfns > size_r); + xen_extra_mem[i].start_pfn += n_pfns; + xen_extra_mem[i].n_pfns -= n_pfns; break; } /* End of region. */ - if (start_r + size_r == start + size) { - BUG_ON(size > size_r); - xen_extra_mem[i].size -= size; + if (start_r + size_r == start_pfn + n_pfns) { + BUG_ON(n_pfns > size_r); + xen_extra_mem[i].n_pfns -= n_pfns; break; } /* Mid of region. */ - if (start > start_r && start < start_r + size_r) { - BUG_ON(start + size > start_r + size_r); - xen_extra_mem[i].size = start - start_r; + if (start_pfn > start_r && start_pfn < start_r + size_r) { + BUG_ON(start_pfn + n_pfns > start_r + size_r); + xen_extra_mem[i].n_pfns = start_pfn - start_r; /* Calling memblock_reserve() again is okay. */ - xen_add_extra_mem(start + size, start_r + size_r - - (start + size)); + xen_add_extra_mem(start_pfn + n_pfns, start_r + size_r - + (start_pfn + n_pfns)); break; } } - memblock_free(start, size); + memblock_free(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns)); } /* @@ -156,11 +163,10 @@ static void __init xen_del_extra_mem(phys_addr_t start, phys_addr_t size) unsigned long __ref xen_chk_extra_mem(unsigned long pfn) { int i; - phys_addr_t addr = PFN_PHYS(pfn); for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) { - if (addr >= xen_extra_mem[i].start && - addr < xen_extra_mem[i].start + xen_extra_mem[i].size) + if (pfn >= xen_extra_mem[i].start_pfn && + pfn < xen_extra_mem[i].start_pfn + xen_extra_mem[i].n_pfns) return INVALID_P2M_ENTRY; } @@ -176,10 +182,10 @@ void __init xen_inv_extra_mem(void) int i; for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) { - if (!xen_extra_mem[i].size) + if (!xen_extra_mem[i].n_pfns) continue; - pfn_s = PFN_DOWN(xen_extra_mem[i].start); - pfn_e = PFN_UP(xen_extra_mem[i].start + xen_extra_mem[i].size); + pfn_s = xen_extra_mem[i].start_pfn; + pfn_e = pfn_s + xen_extra_mem[i].n_pfns; for (pfn = pfn_s; pfn < pfn_e; pfn++) set_phys_to_machine(pfn, INVALID_P2M_ENTRY); } @@ -507,7 +513,7 @@ void __init xen_remap_memory(void) } else if (pfn_s + len == xen_remap_buf.target_pfn) { len += xen_remap_buf.size; } else { - xen_del_extra_mem(PFN_PHYS(pfn_s), PFN_PHYS(len)); + xen_del_extra_mem(pfn_s, len); pfn_s = xen_remap_buf.target_pfn; len = xen_remap_buf.size; } @@ -517,7 +523,7 @@ void __init xen_remap_memory(void) } if (pfn_s != ~0UL && len) - xen_del_extra_mem(PFN_PHYS(pfn_s), PFN_PHYS(len)); + xen_del_extra_mem(pfn_s, len); set_pte_mfn(buf, mfn_save, PAGE_KERNEL); @@ -744,7 +750,7 @@ static void __init xen_reserve_xen_mfnlist(void) **/ char * __init xen_memory_setup(void) { - unsigned long max_pfn; + unsigned long max_pfn, pfn_s, n_pfns; phys_addr_t mem_end, addr, size, chunk_size; u32 type; int rc; @@ -831,9 +837,11 @@ char * __init xen_memory_setup(void) chunk_size = min(size, mem_end - addr); } else if (extra_pages) { chunk_size = min(size, PFN_PHYS(extra_pages)); - extra_pages -= PFN_DOWN(chunk_size); - xen_add_extra_mem(addr, chunk_size); - xen_max_p2m_pfn = PFN_DOWN(addr + chunk_size); + pfn_s = PFN_UP(addr); + n_pfns = PFN_DOWN(addr + chunk_size) - pfn_s; + extra_pages -= n_pfns; + xen_add_extra_mem(pfn_s, n_pfns); + xen_max_p2m_pfn = pfn_s + n_pfns; } else type = E820_UNUSABLE; } diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c index bf4a23c7c591..1fa633b2d556 100644 --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -638,9 +638,9 @@ static int __init balloon_init(void) * regions (see arch/x86/xen/setup.c). */ for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) - if (xen_extra_mem[i].size) - balloon_add_region(PFN_UP(xen_extra_mem[i].start), - PFN_DOWN(xen_extra_mem[i].size)); + if (xen_extra_mem[i].n_pfns) + balloon_add_region(xen_extra_mem[i].start_pfn, + xen_extra_mem[i].n_pfns); return 0; } diff --git a/include/xen/page.h b/include/xen/page.h index c5ed20bb3fe9..a5983da2f5cd 100644 --- a/include/xen/page.h +++ b/include/xen/page.h @@ -9,8 +9,8 @@ static inline unsigned long page_to_mfn(struct page *page) } struct xen_memory_region { - phys_addr_t start; - phys_addr_t size; + unsigned long start_pfn; + unsigned long n_pfns; }; #define XEN_EXTRA_MEM_MAX_REGIONS 128 /* == E820MAX */