diff options
Diffstat (limited to 'arch/x86/xen/p2m.c')
| -rw-r--r-- | arch/x86/xen/p2m.c | 92 |
1 files changed, 85 insertions, 7 deletions
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c index 72213da605f..95fb2aa5927 100644 --- a/arch/x86/xen/p2m.c +++ b/arch/x86/xen/p2m.c @@ -22,7 +22,7 @@ * * P2M_PER_PAGE depends on the architecture, as a mfn is always * unsigned long (8 bytes on 64-bit, 4 bytes on 32), leading to - * 512 and 1024 entries respectively. + * 512 and 1024 entries respectively. * * In short, these structures contain the Machine Frame Number (MFN) of the PFN. * @@ -139,11 +139,11 @@ * / | ~0, ~0, .... | * | \---------------/ * | - * p2m_missing p2m_missing - * /------------------\ /------------\ - * | [p2m_mid_missing]+---->| ~0, ~0, ~0 | - * | [p2m_mid_missing]+---->| ..., ~0 | - * \------------------/ \------------/ + * p2m_mid_missing p2m_missing + * /-----------------\ /------------\ + * | [p2m_missing] +---->| ~0, ~0, ~0 | + * | [p2m_missing] +---->| ..., ~0 | + * \-----------------/ \------------/ * * where ~0 is INVALID_P2M_ENTRY. IDENTITY is (PFN | IDENTITY_BIT) */ @@ -396,7 +396,85 @@ void __init xen_build_dynamic_phys_to_machine(void) m2p_override_init(); } +#ifdef CONFIG_X86_64 +#include <linux/bootmem.h> +unsigned long __init xen_revector_p2m_tree(void) +{ + unsigned long va_start; + unsigned long va_end; + unsigned long pfn; + unsigned long pfn_free = 0; + unsigned long *mfn_list = NULL; + unsigned long size; + + va_start = xen_start_info->mfn_list; + /*We copy in increments of P2M_PER_PAGE * sizeof(unsigned long), + * so make sure it is rounded up to that */ + size = PAGE_ALIGN(xen_start_info->nr_pages * sizeof(unsigned long)); + va_end = va_start + size; + + /* If we were revectored already, don't do it again. */ + if (va_start <= __START_KERNEL_map && va_start >= __PAGE_OFFSET) + return 0; + + mfn_list = alloc_bootmem_align(size, PAGE_SIZE); + if (!mfn_list) { + pr_warn("Could not allocate space for a new P2M tree!\n"); + return xen_start_info->mfn_list; + } + /* Fill it out with INVALID_P2M_ENTRY value */ + memset(mfn_list, 0xFF, size); + + for (pfn = 0; pfn < ALIGN(MAX_DOMAIN_PAGES, P2M_PER_PAGE); pfn += P2M_PER_PAGE) { + unsigned topidx = p2m_top_index(pfn); + unsigned mididx; + unsigned long *mid_p; + + if (!p2m_top[topidx]) + continue; + + if (p2m_top[topidx] == p2m_mid_missing) + continue; + + mididx = p2m_mid_index(pfn); + mid_p = p2m_top[topidx][mididx]; + if (!mid_p) + continue; + if ((mid_p == p2m_missing) || (mid_p == p2m_identity)) + continue; + + if ((unsigned long)mid_p == INVALID_P2M_ENTRY) + continue; + + /* The old va. Rebase it on mfn_list */ + if (mid_p >= (unsigned long *)va_start && mid_p <= (unsigned long *)va_end) { + unsigned long *new; + + if (pfn_free > (size / sizeof(unsigned long))) { + WARN(1, "Only allocated for %ld pages, but we want %ld!\n", + size / sizeof(unsigned long), pfn_free); + return 0; + } + new = &mfn_list[pfn_free]; + + copy_page(new, mid_p); + p2m_top[topidx][mididx] = &mfn_list[pfn_free]; + p2m_top_mfn_p[topidx][mididx] = virt_to_mfn(&mfn_list[pfn_free]); + + pfn_free += P2M_PER_PAGE; + } + /* This should be the leafs allocated for identity from _brk. */ + } + return (unsigned long)mfn_list; + +} +#else +unsigned long __init xen_revector_p2m_tree(void) +{ + return 0; +} +#endif unsigned long get_phys_to_machine(unsigned long pfn) { unsigned topidx, mididx, idx; @@ -430,7 +508,7 @@ static void free_p2m_page(void *p) free_page((unsigned long)p); } -/* +/* * Fully allocate the p2m structure for a given pfn. We need to check * that both the top and mid levels are allocated, and make sure the * parallel mfn tree is kept in sync. We may race with other cpus, so |