diff options
Diffstat (limited to 'arch/x86/xen/p2m.c')
| -rw-r--r-- | arch/x86/xen/p2m.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c index 8b7f18e200aa..b89983e9656f 100644 --- a/arch/x86/xen/p2m.c +++ b/arch/x86/xen/p2m.c @@ -263,6 +263,10 @@ void xen_setup_mfn_list_list(void) 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; + 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 */ @@ -478,8 +482,12 @@ 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; } @@ -577,8 +585,12 @@ 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); p2m = NULL; @@ -630,6 +642,11 @@ 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; |