diff options
Diffstat (limited to 'arch/x86/xen/p2m.c')
| -rw-r--r-- | arch/x86/xen/p2m.c | 62 |
1 files changed, 51 insertions, 11 deletions
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c index 8b7f18e20..660b3cfef 100644 --- a/arch/x86/xen/p2m.c +++ b/arch/x86/xen/p2m.c @@ -79,10 +79,14 @@ #include <xen/balloon.h> #include <xen/grant_table.h> -#include "p2m.h" #include "multicalls.h" #include "xen-ops.h" +#define P2M_MID_PER_PAGE (PAGE_SIZE / sizeof(unsigned long *)) +#define P2M_TOP_PER_PAGE (PAGE_SIZE / sizeof(unsigned long **)) + +#define MAX_P2M_PFN (P2M_TOP_PER_PAGE * P2M_MID_PER_PAGE * P2M_PER_PAGE) + #define PMDS_PER_MID_PAGE (P2M_MID_PER_PAGE / PTRS_PER_PTE) unsigned long *xen_p2m_addr __read_mostly; @@ -108,6 +112,15 @@ static unsigned long *p2m_identity; static pte_t *p2m_missing_pte; static pte_t *p2m_identity_pte; +/* + * Hint at last populated PFN. + * + * Used to set HYPERVISOR_shared_info->arch.max_pfn so the toolstack + * can avoid scanning the whole P2M (which may be sized to account for + * hotplugged memory). + */ +static unsigned long xen_p2m_last_pfn; + static inline unsigned p2m_top_index(unsigned long pfn) { BUG_ON(pfn >= MAX_P2M_PFN); @@ -199,7 +212,8 @@ void __ref xen_build_mfn_list_list(void) unsigned int level, topidx, mididx; unsigned long *mid_mfn_p; - if (xen_feature(XENFEAT_auto_translated_physmap)) + if (xen_feature(XENFEAT_auto_translated_physmap) || + xen_start_info->flags & SIF_VIRT_P2M_4TOOLS) return; /* Pre-initialize p2m_top_mfn to be completely missing */ @@ -260,9 +274,16 @@ void xen_setup_mfn_list_list(void) BUG_ON(HYPERVISOR_shared_info == &xen_dummy_shared_info); - HYPERVISOR_shared_info->arch.pfn_to_mfn_frame_list_list = - virt_to_mfn(p2m_top_mfn); - HYPERVISOR_shared_info->arch.max_pfn = xen_max_p2m_pfn; + if (xen_start_info->flags & SIF_VIRT_P2M_4TOOLS) + HYPERVISOR_shared_info->arch.pfn_to_mfn_frame_list_list = ~0UL; + else + HYPERVISOR_shared_info->arch.pfn_to_mfn_frame_list_list = + virt_to_mfn(p2m_top_mfn); + HYPERVISOR_shared_info->arch.max_pfn = xen_p2m_last_pfn; + HYPERVISOR_shared_info->arch.p2m_generation = 0; + HYPERVISOR_shared_info->arch.p2m_vaddr = (unsigned long)xen_p2m_addr; + HYPERVISOR_shared_info->arch.p2m_cr3 = + xen_pfn_to_cr3(virt_to_mfn(swapper_pg_dir)); } /* Set up p2m_top to point to the domain-builder provided p2m pages */ @@ -394,6 +415,8 @@ void __init xen_vmalloc_p2m_tree(void) static struct vm_struct vm; unsigned long p2m_limit; + xen_p2m_last_pfn = xen_max_p2m_pfn; + p2m_limit = (phys_addr_t)P2M_LIMIT * 1024 * 1024 * 1024 / PAGE_SIZE; vm.flags = VM_ALLOC; vm.size = ALIGN(sizeof(unsigned long) * max(xen_max_p2m_pfn, p2m_limit), @@ -478,8 +501,12 @@ static pte_t *alloc_p2m_pmd(unsigned long addr, pte_t *pte_pg) ptechk = lookup_address(vaddr, &level); if (ptechk == pte_pg) { + HYPERVISOR_shared_info->arch.p2m_generation++; + wmb(); /* Tools are synchronizing via p2m_generation. */ set_pmd(pmdp, __pmd(__pa(pte_newpg[i]) | _KERNPG_TABLE)); + wmb(); /* Tools are synchronizing via p2m_generation. */ + HYPERVISOR_shared_info->arch.p2m_generation++; pte_newpg[i] = NULL; } @@ -505,7 +532,7 @@ 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; @@ -513,9 +540,6 @@ 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)); @@ -527,7 +551,8 @@ 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]); @@ -577,10 +602,14 @@ static bool alloc_p2m(unsigned long pfn) spin_lock_irqsave(&p2m_update_lock, flags); if (pte_pfn(*ptep) == p2m_pfn) { + HYPERVISOR_shared_info->arch.p2m_generation++; + wmb(); /* Tools are synchronizing via p2m_generation. */ set_pte(ptep, pfn_pte(PFN_DOWN(__pa(p2m)), PAGE_KERNEL)); + 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; } @@ -590,6 +619,12 @@ static bool alloc_p2m(unsigned long pfn) free_p2m_page(p2m); } + /* Expanded the p2m? */ + if (pfn > xen_p2m_last_pfn) { + xen_p2m_last_pfn = pfn; + HYPERVISOR_shared_info->arch.max_pfn = xen_p2m_last_pfn; + } + return true; } @@ -630,6 +665,11 @@ bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn) return true; } + /* + * The interface requires atomic updates on p2m elements. + * xen_safe_write_ulong() is using __put_user which does an atomic + * store via asm(). + */ if (likely(!xen_safe_write_ulong(xen_p2m_addr + pfn, mfn))) return true; |