From 6eaa412f2753d98566b777836a98c6e7f672a3bb Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Tue, 18 Jan 2011 20:09:41 -0500 Subject: xen: Mark all initial reserved pages for the balloon as INVALID_P2M_ENTRY. With this patch, we diligently set regions that will be used by the balloon driver to be INVALID_P2M_ENTRY and under the ownership of the balloon driver. We are OK using the __set_phys_to_machine as we do not expect to be allocating any P2M middle or entries pages. The set_phys_to_machine has the side-effect of potentially allocating new pages and we do not want that at this stage. We can do this because xen_build_mfn_list_list will have already allocated all such pages up to xen_max_p2m_pfn. We also move the check for auto translated physmap down the stack so it is present in __set_phys_to_machine. [v2: Rebased with mmu->p2m code split] Reviewed-by: Ian Campbell Signed-off-by: Konrad Rzeszutek Wilk --- arch/x86/xen/mmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86/xen/mmu.c') diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index 5e92b61ad574..0180ae88307b 100644 --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -2074,7 +2074,7 @@ static void xen_zap_pfn_range(unsigned long vaddr, unsigned int order, in_frames[i] = virt_to_mfn(vaddr); MULTI_update_va_mapping(mcs.mc, vaddr, VOID_PTE, 0); - set_phys_to_machine(virt_to_pfn(vaddr), INVALID_P2M_ENTRY); + __set_phys_to_machine(virt_to_pfn(vaddr), INVALID_P2M_ENTRY); if (out_frames) out_frames[i] = virt_to_pfn(vaddr); -- cgit v1.2.3 From fb38923ead10aa8a28db191548e176e8856614d7 Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Wed, 5 Jan 2011 15:46:31 -0500 Subject: xen/mmu: Set _PAGE_IOMAP if PFN is an identity PFN. If we find that the PFN is within the P2M as an identity PFN make sure to tack on the _PAGE_IOMAP flag. Reviewed-by: Ian Campbell Signed-off-by: Konrad Rzeszutek Wilk --- arch/x86/xen/mmu.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) (limited to 'arch/x86/xen/mmu.c') diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index 0180ae88307b..9c9e07615139 100644 --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -416,8 +416,12 @@ static pteval_t pte_pfn_to_mfn(pteval_t val) if (val & _PAGE_PRESENT) { unsigned long pfn = (val & PTE_PFN_MASK) >> PAGE_SHIFT; pteval_t flags = val & PTE_FLAGS_MASK; - unsigned long mfn = pfn_to_mfn(pfn); + unsigned long mfn; + if (!xen_feature(XENFEAT_auto_translated_physmap)) + mfn = get_phys_to_machine(pfn); + else + mfn = pfn; /* * If there's no mfn for the pfn, then just create an * empty non-present pte. Unfortunately this loses @@ -427,8 +431,18 @@ static pteval_t pte_pfn_to_mfn(pteval_t val) if (unlikely(mfn == INVALID_P2M_ENTRY)) { mfn = 0; flags = 0; + } else { + /* + * Paramount to do this test _after_ the + * INVALID_P2M_ENTRY as INVALID_P2M_ENTRY & + * IDENTITY_FRAME_BIT resolves to true. + */ + mfn &= ~FOREIGN_FRAME_BIT; + if (mfn & IDENTITY_FRAME_BIT) { + mfn &= ~IDENTITY_FRAME_BIT; + flags |= _PAGE_IOMAP; + } } - val = ((pteval_t)mfn << PAGE_SHIFT) | flags; } -- cgit v1.2.3 From 2222e71bd6eff7b2ad026d4ee663b6327c5a49f5 Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Wed, 22 Dec 2010 08:57:30 -0500 Subject: xen/debugfs: Add 'p2m' file for printing out the P2M layout. We walk over the whole P2M tree and construct a simplified view of which PFN regions belong to what level and what type they are. Only enabled if CONFIG_XEN_DEBUG_FS is set. [v2: UNKN->UNKNOWN, use uninitialized_var] [v3: Rebased on top of mmu->p2m code split] [v4: Fixed the else if] Reviewed-by: Ian Campbell Signed-off-by: Konrad Rzeszutek Wilk --- arch/x86/include/asm/xen/page.h | 3 ++ arch/x86/xen/mmu.c | 14 ++++++++ arch/x86/xen/p2m.c | 78 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 95 insertions(+) (limited to 'arch/x86/xen/mmu.c') diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h index 65fa4f26aa34..78ebbeb88d9c 100644 --- a/arch/x86/include/asm/xen/page.h +++ b/arch/x86/include/asm/xen/page.h @@ -52,6 +52,9 @@ extern int m2p_remove_override(struct page *page); extern struct page *m2p_find_override(unsigned long mfn); extern unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn); +#ifdef CONFIG_XEN_DEBUG_FS +extern int p2m_dump_show(struct seq_file *m, void *v); +#endif static inline unsigned long pfn_to_mfn(unsigned long pfn) { unsigned long mfn; diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index 9c9e07615139..b13b6ca9052a 100644 --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -46,6 +46,7 @@ #include #include #include +#include #include #include @@ -2367,6 +2368,18 @@ EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range); #ifdef CONFIG_XEN_DEBUG_FS +static int p2m_dump_open(struct inode *inode, struct file *filp) +{ + return single_open(filp, p2m_dump_show, NULL); +} + +static const struct file_operations p2m_dump_fops = { + .open = p2m_dump_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + static struct dentry *d_mmu_debug; static int __init xen_mmu_debugfs(void) @@ -2422,6 +2435,7 @@ static int __init xen_mmu_debugfs(void) debugfs_create_u32("prot_commit_batched", 0444, d_mmu_debug, &mmu_stats.prot_commit_batched); + debugfs_create_file("p2m", 0600, d_mmu_debug, NULL, &p2m_dump_fops); return 0; } fs_initcall(xen_mmu_debugfs); diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c index 4631cf99e714..65f21f4b3962 100644 --- a/arch/x86/xen/p2m.c +++ b/arch/x86/xen/p2m.c @@ -153,6 +153,7 @@ #include #include #include +#include #include #include @@ -758,3 +759,80 @@ unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn) return ret; } EXPORT_SYMBOL_GPL(m2p_find_override_pfn); + +#ifdef CONFIG_XEN_DEBUG_FS + +int p2m_dump_show(struct seq_file *m, void *v) +{ + static const char * const level_name[] = { "top", "middle", + "entry", "abnormal" }; + static const char * const type_name[] = { "identity", "missing", + "pfn", "abnormal"}; +#define TYPE_IDENTITY 0 +#define TYPE_MISSING 1 +#define TYPE_PFN 2 +#define TYPE_UNKNOWN 3 + unsigned long pfn, prev_pfn_type = 0, prev_pfn_level = 0; + unsigned int uninitialized_var(prev_level); + unsigned int uninitialized_var(prev_type); + + if (!p2m_top) + return 0; + + for (pfn = 0; pfn < MAX_DOMAIN_PAGES; pfn++) { + unsigned topidx = p2m_top_index(pfn); + unsigned mididx = p2m_mid_index(pfn); + unsigned idx = p2m_index(pfn); + unsigned lvl, type; + + lvl = 4; + type = TYPE_UNKNOWN; + if (p2m_top[topidx] == p2m_mid_missing) { + lvl = 0; type = TYPE_MISSING; + } else if (p2m_top[topidx] == NULL) { + lvl = 0; type = TYPE_UNKNOWN; + } else if (p2m_top[topidx][mididx] == NULL) { + lvl = 1; type = TYPE_UNKNOWN; + } else if (p2m_top[topidx][mididx] == p2m_identity) { + lvl = 1; type = TYPE_IDENTITY; + } else if (p2m_top[topidx][mididx] == p2m_missing) { + lvl = 1; type = TYPE_MISSING; + } else if (p2m_top[topidx][mididx][idx] == 0) { + lvl = 2; type = TYPE_UNKNOWN; + } else if (p2m_top[topidx][mididx][idx] == IDENTITY_FRAME(pfn)) { + lvl = 2; type = TYPE_IDENTITY; + } else if (p2m_top[topidx][mididx][idx] == INVALID_P2M_ENTRY) { + lvl = 2; type = TYPE_MISSING; + } else if (p2m_top[topidx][mididx][idx] == pfn) { + lvl = 2; type = TYPE_PFN; + } else if (p2m_top[topidx][mididx][idx] != pfn) { + lvl = 2; type = TYPE_PFN; + } + if (pfn == 0) { + prev_level = lvl; + prev_type = type; + } + if (pfn == MAX_DOMAIN_PAGES-1) { + lvl = 3; + type = TYPE_UNKNOWN; + } + if (prev_type != type) { + seq_printf(m, " [0x%lx->0x%lx] %s\n", + prev_pfn_type, pfn, type_name[prev_type]); + prev_pfn_type = pfn; + prev_type = type; + } + if (prev_level != lvl) { + seq_printf(m, " [0x%lx->0x%lx] level %s\n", + prev_pfn_level, pfn, level_name[prev_level]); + prev_pfn_level = pfn; + prev_level = lvl; + } + } + return 0; +#undef TYPE_IDENTITY +#undef TYPE_MISSING +#undef TYPE_PFN +#undef TYPE_UNKNOWN +} +#endif -- cgit v1.2.3 From fc25151d9ac7d809239fe68de0a1490b504bb94a Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Thu, 23 Dec 2010 16:25:29 -0500 Subject: xen/debug: WARN_ON when identity PFN has no _PAGE_IOMAP flag set. Only enabled if XEN_DEBUG is enabled. We print a warning when: pfn_to_mfn(pfn) == pfn, but no VM_IO (_PAGE_IOMAP) flag set (and pfn is an identity mapped pfn) pfn_to_mfn(pfn) != pfn, and VM_IO flag is set. (ditto, pfn is an identity mapped pfn) [v2: Make it dependent on CONFIG_XEN_DEBUG instead of ..DEBUG_FS] [v3: Fix compiler warning] Reviewed-by: Ian Campbell Signed-off-by: Konrad Rzeszutek Wilk --- arch/x86/xen/Kconfig | 8 ++++++++ arch/x86/xen/mmu.c | 38 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 46 insertions(+) (limited to 'arch/x86/xen/mmu.c') diff --git a/arch/x86/xen/Kconfig b/arch/x86/xen/Kconfig index 5b54892e4bc3..e4343fe488ed 100644 --- a/arch/x86/xen/Kconfig +++ b/arch/x86/xen/Kconfig @@ -48,3 +48,11 @@ config XEN_DEBUG_FS help Enable statistics output and various tuning options in debugfs. Enabling this option may incur a significant performance overhead. + +config XEN_DEBUG + bool "Enable Xen debug checks" + depends on XEN + default n + help + Enable various WARN_ON checks in the Xen MMU code. + Enabling this option WILL incur a significant performance overhead. diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index b13b6ca9052a..0c376a2d9f98 100644 --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -547,6 +547,41 @@ pte_t xen_make_pte(pteval_t pte) } PV_CALLEE_SAVE_REGS_THUNK(xen_make_pte); +#ifdef CONFIG_XEN_DEBUG +pte_t xen_make_pte_debug(pteval_t pte) +{ + phys_addr_t addr = (pte & PTE_PFN_MASK); + phys_addr_t other_addr; + bool io_page = false; + pte_t _pte; + + if (pte & _PAGE_IOMAP) + io_page = true; + + _pte = xen_make_pte(pte); + + if (!addr) + return _pte; + + if (io_page && + (xen_initial_domain() || addr >= ISA_END_ADDRESS)) { + other_addr = pfn_to_mfn(addr >> PAGE_SHIFT) << PAGE_SHIFT; + WARN(addr != other_addr, + "0x%lx is using VM_IO, but it is 0x%lx!\n", + (unsigned long)addr, (unsigned long)other_addr); + } else { + pteval_t iomap_set = (_pte.pte & PTE_FLAGS_MASK) & _PAGE_IOMAP; + other_addr = (_pte.pte & PTE_PFN_MASK); + WARN((addr == other_addr) && (!io_page) && (!iomap_set), + "0x%lx is missing VM_IO (and wasn't fixed)!\n", + (unsigned long)addr); + } + + return _pte; +} +PV_CALLEE_SAVE_REGS_THUNK(xen_make_pte_debug); +#endif + pgd_t xen_make_pgd(pgdval_t pgd) { pgd = pte_pfn_to_mfn(pgd); @@ -1957,6 +1992,9 @@ __init void xen_ident_map_ISA(void) static __init void xen_post_allocator_init(void) { +#ifdef CONFIG_XEN_DEBUG + pv_mmu_ops.make_pte = PV_CALLEE_SAVE(xen_make_pte_debug); +#endif pv_mmu_ops.set_pte = xen_set_pte; pv_mmu_ops.set_pmd = xen_set_pmd; pv_mmu_ops.set_pud = xen_set_pud; -- cgit v1.2.3