diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/xen/mmu.c | 50 |
1 files changed, 37 insertions, 13 deletions
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index 67b4101..e41683c 100644 --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -187,6 +187,8 @@ DEFINE_PER_CPU(unsigned long, xen_current_cr3); /* actual vcpu cr3 */ * / \ / \ / / * p2m p2m p2m p2m p2m p2m p2m ... * + * The p2m_mid_mfn pages are mapped by p2m_top_mfn_p. + * * The p2m_top and p2m_top_mfn levels are limited to 1 page, so the * maximum representable pseudo-physical address space is: * P2M_TOP_PER_PAGE * P2M_MID_PER_PAGE * P2M_PER_PAGE pages @@ -211,6 +213,7 @@ static RESERVE_BRK_ARRAY(unsigned long, p2m_mid_missing_mfn, P2M_MID_PER_PAGE); static RESERVE_BRK_ARRAY(unsigned long **, p2m_top, P2M_TOP_PER_PAGE); static RESERVE_BRK_ARRAY(unsigned long, p2m_top_mfn, P2M_TOP_PER_PAGE); +static RESERVE_BRK_ARRAY(unsigned long *, p2m_top_mfn_p, P2M_TOP_PER_PAGE); RESERVE_BRK(p2m_mid, PAGE_SIZE * (MAX_DOMAIN_PAGES / (P2M_PER_PAGE * P2M_MID_PER_PAGE))); RESERVE_BRK(p2m_mid_mfn, PAGE_SIZE * (MAX_DOMAIN_PAGES / (P2M_PER_PAGE * P2M_MID_PER_PAGE))); @@ -247,6 +250,14 @@ static void p2m_top_mfn_init(unsigned long *top) top[i] = virt_to_mfn(p2m_mid_missing_mfn); } +static void p2m_top_mfn_p_init(unsigned long **top) +{ + unsigned i; + + for (i = 0; i < P2M_TOP_PER_PAGE; i++) + top[i] = p2m_mid_missing_mfn; +} + static void p2m_mid_init(unsigned long **mid) { unsigned i; @@ -283,33 +294,43 @@ static void p2m_init(unsigned long *p2m) */ void xen_build_mfn_list_list(void) { - unsigned pfn; + unsigned long pfn; /* Pre-initialize p2m_top_mfn to be completely missing */ if (p2m_top_mfn == NULL) { p2m_mid_missing_mfn = extend_brk(PAGE_SIZE, PAGE_SIZE); p2m_mid_mfn_init(p2m_mid_missing_mfn); + p2m_top_mfn_p = extend_brk(PAGE_SIZE, PAGE_SIZE); + p2m_top_mfn_p_init(p2m_top_mfn_p); + p2m_top_mfn = extend_brk(PAGE_SIZE, PAGE_SIZE); p2m_top_mfn_init(p2m_top_mfn); + } else { + /* Reinitialise, mfn's all change after migration */ + p2m_mid_mfn_init(p2m_mid_missing_mfn); } for (pfn = 0; pfn < xen_max_p2m_pfn; pfn += P2M_PER_PAGE) { unsigned topidx = p2m_top_index(pfn); unsigned mididx = p2m_mid_index(pfn); unsigned long **mid; - unsigned long mid_mfn; unsigned long *mid_mfn_p; mid = p2m_top[topidx]; + mid_mfn_p = p2m_top_mfn_p[topidx]; /* Don't bother allocating any mfn mid levels if - they're just missing */ - if (mid[mididx] == p2m_missing) + * they're just missing, just update the stored mfn, + * since all could have changed over a migrate. + */ + if (mid == p2m_mid_missing) { + BUG_ON(mididx); + BUG_ON(mid_mfn_p != p2m_mid_missing_mfn); + p2m_top_mfn[topidx] = virt_to_mfn(p2m_mid_missing_mfn); + pfn += (P2M_MID_PER_PAGE - 1) * P2M_PER_PAGE; continue; - - mid_mfn = p2m_top_mfn[topidx]; - mid_mfn_p = mfn_to_virt(mid_mfn); + } if (mid_mfn_p == p2m_mid_missing_mfn) { /* @@ -321,11 +342,10 @@ void xen_build_mfn_list_list(void) mid_mfn_p = extend_brk(PAGE_SIZE, PAGE_SIZE); p2m_mid_mfn_init(mid_mfn_p); - mid_mfn = virt_to_mfn(mid_mfn_p); - - p2m_top_mfn[topidx] = mid_mfn; + p2m_top_mfn_p[topidx] = mid_mfn_p; } + p2m_top_mfn[topidx] = virt_to_mfn(mid_mfn_p); mid_mfn_p[mididx] = virt_to_mfn(mid[mididx]); } } @@ -344,7 +364,7 @@ void __init xen_build_dynamic_phys_to_machine(void) { unsigned long *mfn_list = (unsigned long *)xen_start_info->mfn_list; unsigned long max_pfn = min(MAX_DOMAIN_PAGES, xen_start_info->nr_pages); - unsigned pfn; + unsigned long pfn; xen_max_p2m_pfn = max_pfn; @@ -434,7 +454,9 @@ static bool alloc_p2m(unsigned long pfn) } top_mfn_p = &p2m_top_mfn[topidx]; - mid_mfn = mfn_to_virt(*top_mfn_p); + mid_mfn = p2m_top_mfn_p[topidx]; + + BUG_ON(virt_to_mfn(mid_mfn) != *top_mfn_p); if (mid_mfn == p2m_mid_missing_mfn) { /* Separately check the mid mfn level */ @@ -446,11 +468,13 @@ static bool alloc_p2m(unsigned long pfn) return false; p2m_mid_mfn_init(mid_mfn); - + missing_mfn = virt_to_mfn(p2m_mid_missing_mfn); mid_mfn_mfn = virt_to_mfn(mid_mfn); if (cmpxchg(top_mfn_p, missing_mfn, mid_mfn_mfn) != missing_mfn) free_p2m_page(mid_mfn); + else + p2m_top_mfn_p[topidx] = mid_mfn; } if (p2m_top[topidx][mididx] == p2m_missing) { |
