From f64337062c09c2c318fbcbf44ed1d739e8bc72ab Mon Sep 17 00:00:00 2001 From: Mark McLoughlin Date: Wed, 2 Apr 2008 15:36:36 +0100 Subject: xen: refactor xen_{alloc,release}_{pt,pd}() Signed-off-by: Mark McLoughlin Cc: xen-devel@lists.xensource.com Cc: Mark McLoughlin Cc: Jeremy Fitzhardinge Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar --- arch/x86/xen/enlighten.c | 27 ++++++++++++++++++++------- arch/x86/xen/mmu.c | 7 ------- arch/x86/xen/mmu.h | 7 +++++++ 3 files changed, 27 insertions(+), 14 deletions(-) (limited to 'arch/x86/xen') diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index de4e6f05840b..16e2f8096a1a 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -667,10 +667,10 @@ static void xen_release_pt_init(u32 pfn) make_lowmem_page_readwrite(__va(PFN_PHYS(pfn))); } -static void pin_pagetable_pfn(unsigned level, unsigned long pfn) +static void pin_pagetable_pfn(unsigned cmd, unsigned long pfn) { struct mmuext_op op; - op.cmd = level; + op.cmd = cmd; op.arg1.mfn = pfn_to_mfn(pfn); if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF)) BUG(); @@ -687,7 +687,10 @@ static void xen_alloc_ptpage(struct mm_struct *mm, u32 pfn, unsigned level) if (!PageHighMem(page)) { make_lowmem_page_readonly(__va(PFN_PHYS(pfn))); - pin_pagetable_pfn(level, pfn); + if (level == PT_PTE) + pin_pagetable_pfn(MMUEXT_PIN_L1_TABLE, pfn); + else if (level == PT_PMD) + pin_pagetable_pfn(MMUEXT_PIN_L2_TABLE, pfn); } else /* make sure there are no stray mappings of this page */ @@ -697,16 +700,16 @@ static void xen_alloc_ptpage(struct mm_struct *mm, u32 pfn, unsigned level) static void xen_alloc_pt(struct mm_struct *mm, u32 pfn) { - xen_alloc_ptpage(mm, pfn, MMUEXT_PIN_L1_TABLE); + xen_alloc_ptpage(mm, pfn, PT_PTE); } static void xen_alloc_pd(struct mm_struct *mm, u32 pfn) { - xen_alloc_ptpage(mm, pfn, MMUEXT_PIN_L2_TABLE); + xen_alloc_ptpage(mm, pfn, PT_PMD); } /* This should never happen until we're OK to use struct page */ -static void xen_release_pt(u32 pfn) +static void xen_release_ptpage(u32 pfn, unsigned level) { struct page *page = pfn_to_page(pfn); @@ -718,6 +721,16 @@ static void xen_release_pt(u32 pfn) } } +static void xen_release_pt(u32 pfn) +{ + xen_release_ptpage(pfn, PT_PTE); +} + +static void xen_release_pd(u32 pfn) +{ + xen_release_ptpage(pfn, PT_PMD); +} + #ifdef CONFIG_HIGHPTE static void *xen_kmap_atomic_pte(struct page *page, enum km_type type) { @@ -838,7 +851,7 @@ static __init void xen_pagetable_setup_done(pgd_t *base) pv_mmu_ops.alloc_pt = xen_alloc_pt; pv_mmu_ops.alloc_pd = xen_alloc_pd; pv_mmu_ops.release_pt = xen_release_pt; - pv_mmu_ops.release_pd = xen_release_pt; + pv_mmu_ops.release_pd = xen_release_pd; pv_mmu_ops.set_pte = xen_set_pte; setup_shared_info(); diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index 0144395448ae..2a054ef2a3da 100644 --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -310,13 +310,6 @@ pgd_t xen_make_pgd(unsigned long pgd) } #endif /* CONFIG_X86_PAE */ -enum pt_level { - PT_PGD, - PT_PUD, - PT_PMD, - PT_PTE -}; - /* (Yet another) pagetable walker. This one is intended for pinning a pagetable. This means that it walks a pagetable and calls the diff --git a/arch/x86/xen/mmu.h b/arch/x86/xen/mmu.h index c9ff27f3ac3a..b5e189b1519d 100644 --- a/arch/x86/xen/mmu.h +++ b/arch/x86/xen/mmu.h @@ -3,6 +3,13 @@ #include #include +enum pt_level { + PT_PGD, + PT_PUD, + PT_PMD, + PT_PTE +}; + /* * Page-directory addresses above 4GB do not fit into architectural %cr3. * When accessing %cr3, or equivalent field in vcpu_guest_context, guests -- cgit v1.2.3 From a684d69d15a8fafede7c5c0daac8c646bbee805c Mon Sep 17 00:00:00 2001 From: Mark McLoughlin Date: Wed, 2 Apr 2008 15:36:37 +0100 Subject: xen: Do not pin/unpin PMD pages i.e. with this simple test case: int fd = open("/dev/zero", O_RDONLY); munmap(mmap((void *)0x40000000, 0x1000_LEN, PROT_READ, MAP_PRIVATE, fd, 0), 0x1000); close(fd); we currently get: kernel BUG at arch/x86/xen/enlighten.c:678! ... EIP is at xen_release_pt+0x79/0xa9 ... Call Trace: [] ? __pmd_free_tlb+0x1a/0x75 [] ? free_pgd_range+0x1d2/0x2b5 [] ? free_pgtables+0x7e/0x93 [] ? unmap_region+0xb9/0xf5 [] ? do_munmap+0x193/0x1f5 [] ? sys_munmap+0x30/0x3f [] ? syscall_call+0x7/0xb ======================= and xen complains: (XEN) mm.c:2241:d4 Mfn 1cc37 not pinned Further details at: https://bugzilla.redhat.com/436453 Signed-off-by: Mark McLoughlin Cc: xen-devel@lists.xensource.com Cc: Mark McLoughlin Cc: Jeremy Fitzhardinge Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar --- arch/x86/xen/enlighten.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'arch/x86/xen') diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 16e2f8096a1a..f16b056e5c56 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -689,8 +689,6 @@ static void xen_alloc_ptpage(struct mm_struct *mm, u32 pfn, unsigned level) make_lowmem_page_readonly(__va(PFN_PHYS(pfn))); if (level == PT_PTE) pin_pagetable_pfn(MMUEXT_PIN_L1_TABLE, pfn); - else if (level == PT_PMD) - pin_pagetable_pfn(MMUEXT_PIN_L2_TABLE, pfn); } else /* make sure there are no stray mappings of this page */ @@ -715,7 +713,8 @@ static void xen_release_ptpage(u32 pfn, unsigned level) if (PagePinned(page)) { if (!PageHighMem(page)) { - pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, pfn); + if (level == PT_PTE) + pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, pfn); make_lowmem_page_readwrite(__va(PFN_PHYS(pfn))); } } -- cgit v1.2.3 From c946c7de49a9ba50bc205d6359b41bbc8f01174c Mon Sep 17 00:00:00 2001 From: Mark McLoughlin Date: Wed, 2 Apr 2008 15:36:38 +0100 Subject: xen: Clear PG_pinned in release_{pt,pd}() Signed-off-by: Mark McLoughlin Cc: xen-devel@lists.xensource.com Cc: Mark McLoughlin Cc: Jeremy Fitzhardinge Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar --- arch/x86/xen/enlighten.c | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/x86/xen') diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index f16b056e5c56..27ee26aedf94 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -717,6 +717,7 @@ static void xen_release_ptpage(u32 pfn, unsigned level) pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, pfn); make_lowmem_page_readwrite(__va(PFN_PHYS(pfn))); } + ClearPagePinned(page); } } -- cgit v1.2.3