From 8edfcf882eb91ec9028c7334f90f6ef3db5b0fcf Mon Sep 17 00:00:00 2001 From: David Vrabel Date: Wed, 22 Jul 2015 14:48:09 +0100 Subject: [PATCH] x86/xen: export xen_alloc_p2m_entry() Rename alloc_p2m() to xen_alloc_p2m_entry() and export it. This is useful for ensuring that a p2m entry is allocated (i.e., not a shared missing or identity entry) so that subsequent set_phys_to_machine() calls will require no further allocations. Signed-off-by: David Vrabel Reviewed-by: Daniel Kiper --- v3: - Make xen_alloc_p2m_entry() a nop on auto-xlate guests. --- arch/x86/include/asm/xen/page.h | 2 ++ arch/x86/xen/p2m.c | 19 +++++++++++++------ 2 files changed, 15 insertions(+), 6 deletions(-) diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h index 0679e11..b922fa4 100644 --- a/arch/x86/include/asm/xen/page.h +++ b/arch/x86/include/asm/xen/page.h @@ -43,6 +43,8 @@ extern unsigned long *xen_p2m_addr; extern unsigned long xen_p2m_size; extern unsigned long xen_max_p2m_pfn; +extern int xen_alloc_p2m_entry(unsigned long pfn); + extern unsigned long get_phys_to_machine(unsigned long pfn); extern bool set_phys_to_machine(unsigned long pfn, unsigned long mfn); extern bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn); diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c index 660b3cf..cab9f76 100644 --- a/arch/x86/xen/p2m.c +++ b/arch/x86/xen/p2m.c @@ -530,7 +530,7 @@ static pte_t *alloc_p2m_pmd(unsigned long addr, pte_t *pte_pg) * the new pages are installed with cmpxchg; if we lose the race then * simply free the page we allocated and use the one that's there. */ -static bool alloc_p2m(unsigned long pfn) +int xen_alloc_p2m_entry(unsigned long pfn) { unsigned topidx; unsigned long *top_mfn_p, *mid_mfn; @@ -540,6 +540,9 @@ static bool alloc_p2m(unsigned long pfn) unsigned long addr = (unsigned long)(xen_p2m_addr + pfn); unsigned long p2m_pfn; + if (xen_feature(XENFEAT_auto_translated_physmap)) + return 0; + ptep = lookup_address(addr, &level); BUG_ON(!ptep || level != PG_LEVEL_4K); pte_pg = (pte_t *)((unsigned long)ptep & ~(PAGE_SIZE - 1)); @@ -548,7 +551,7 @@ static bool alloc_p2m(unsigned long pfn) /* PMD level is missing, allocate a new one */ ptep = alloc_p2m_pmd(addr, pte_pg); if (!ptep) - return false; + return -ENOMEM; } if (p2m_top_mfn && pfn < MAX_P2M_PFN) { @@ -566,7 +569,7 @@ static bool alloc_p2m(unsigned long pfn) mid_mfn = alloc_p2m_page(); if (!mid_mfn) - return false; + return -ENOMEM; p2m_mid_mfn_init(mid_mfn, p2m_missing); @@ -592,7 +595,7 @@ static bool alloc_p2m(unsigned long pfn) p2m = alloc_p2m_page(); if (!p2m) - return false; + return -ENOMEM; if (p2m_pfn == PFN_DOWN(__pa(p2m_missing))) p2m_init(p2m); @@ -625,8 +628,9 @@ static bool alloc_p2m(unsigned long pfn) HYPERVISOR_shared_info->arch.max_pfn = xen_p2m_last_pfn; } - return true; + return 0; } +EXPORT_SYMBOL(xen_alloc_p2m_entry); unsigned long __init set_phys_range_identity(unsigned long pfn_s, unsigned long pfn_e) @@ -688,7 +692,10 @@ bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn) bool set_phys_to_machine(unsigned long pfn, unsigned long mfn) { if (unlikely(!__set_phys_to_machine(pfn, mfn))) { - if (!alloc_p2m(pfn)) + int ret; + + ret = xen_alloc_p2m_entry(pfn); + if (ret < 0) return false; return __set_phys_to_machine(pfn, mfn); -- 2.7.4