diff options
Diffstat (limited to 'arch/x86/xen/mmu.c')
| -rw-r--r-- | arch/x86/xen/mmu.c | 900 |
1 files changed, 809 insertions, 91 deletions
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index 914f04695ce5..c237b810b03f 100644 --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -42,8 +42,10 @@ #include <linux/highmem.h> #include <linux/debugfs.h> #include <linux/bug.h> +#include <linux/vmalloc.h> #include <linux/module.h> #include <linux/gfp.h> +#include <linux/memblock.h> #include <asm/pgtable.h> #include <asm/tlbflush.h> @@ -51,14 +53,21 @@ #include <asm/mmu_context.h> #include <asm/setup.h> #include <asm/paravirt.h> +#include <asm/e820.h> #include <asm/linkage.h> +#include <asm/page.h> +#include <asm/init.h> +#include <asm/pat.h> #include <asm/xen/hypercall.h> #include <asm/xen/hypervisor.h> +#include <xen/xen.h> #include <xen/page.h> #include <xen/interface/xen.h> +#include <xen/interface/hvm/hvm_op.h> #include <xen/interface/version.h> +#include <xen/interface/memory.h> #include <xen/hvc-console.h> #include "multicalls.h" @@ -67,6 +76,13 @@ #define MMU_UPDATE_HISTO 30 +/* + * Protects atomic reservation decrease/increase against concurrent increases. + * Also protects non-atomic updates of current_pages and driver_pages, and + * balloon lists. + */ +DEFINE_SPINLOCK(xen_reservation_lock); + #ifdef CONFIG_XEN_DEBUG_FS static struct { @@ -125,7 +141,8 @@ static inline void check_zero(void) * large enough to allocate page table pages to allocate the rest. * Each page can map 2MB. */ -static pte_t level1_ident_pgt[PTRS_PER_PTE * 4] __page_aligned_bss; +#define LEVEL1_IDENT_ENTRIES (PTRS_PER_PTE * 4) +static RESERVE_BRK_ARRAY(pte_t, level1_ident_pgt, LEVEL1_IDENT_ENTRIES); #ifdef CONFIG_X86_64 /* l3 pud for userspace vsyscall mapping */ @@ -156,49 +173,182 @@ DEFINE_PER_CPU(unsigned long, xen_current_cr3); /* actual vcpu cr3 */ */ #define USER_LIMIT ((STACK_TOP_MAX + PGDIR_SIZE - 1) & PGDIR_MASK) +/* + * Xen leaves the responsibility for maintaining p2m mappings to the + * guests themselves, but it must also access and update the p2m array + * during suspend/resume when all the pages are reallocated. + * + * The p2m table is logically a flat array, but we implement it as a + * three-level tree to allow the address space to be sparse. + * + * Xen + * | + * p2m_top p2m_top_mfn + * / \ / \ + * p2m_mid p2m_mid p2m_mid_mfn p2m_mid_mfn + * / \ / \ / / + * p2m p2m p2m p2m p2m p2m p2m ... + * + * The p2m_mid_mfn pages are mapped by p2m_top_mfn_p. + * + * The p2m_top and p2m_top_mfn levels are limited to 1 page, so the + * maximum representable pseudo-physical address space is: + * P2M_TOP_PER_PAGE * P2M_MID_PER_PAGE * P2M_PER_PAGE pages + * + * P2M_PER_PAGE depends on the architecture, as a mfn is always + * unsigned long (8 bytes on 64-bit, 4 bytes on 32), leading to + * 512 and 1024 entries respectively. + */ + +unsigned long xen_max_p2m_pfn __read_mostly; -#define P2M_ENTRIES_PER_PAGE (PAGE_SIZE / sizeof(unsigned long)) -#define TOP_ENTRIES (MAX_DOMAIN_PAGES / P2M_ENTRIES_PER_PAGE) +#define P2M_PER_PAGE (PAGE_SIZE / sizeof(unsigned long)) +#define P2M_MID_PER_PAGE (PAGE_SIZE / sizeof(unsigned long *)) +#define P2M_TOP_PER_PAGE (PAGE_SIZE / sizeof(unsigned long **)) -/* Placeholder for holes in the address space */ -static unsigned long p2m_missing[P2M_ENTRIES_PER_PAGE] __page_aligned_data = - { [ 0 ... P2M_ENTRIES_PER_PAGE-1 ] = ~0UL }; +#define MAX_P2M_PFN (P2M_TOP_PER_PAGE * P2M_MID_PER_PAGE * P2M_PER_PAGE) - /* Array of pointers to pages containing p2m entries */ -static unsigned long *p2m_top[TOP_ENTRIES] __page_aligned_data = - { [ 0 ... TOP_ENTRIES - 1] = &p2m_missing[0] }; +/* Placeholders for holes in the address space */ +static RESERVE_BRK_ARRAY(unsigned long, p2m_missing, P2M_PER_PAGE); +static RESERVE_BRK_ARRAY(unsigned long *, p2m_mid_missing, P2M_MID_PER_PAGE); +static RESERVE_BRK_ARRAY(unsigned long, p2m_mid_missing_mfn, P2M_MID_PER_PAGE); -/* Arrays of p2m arrays expressed in mfns used for save/restore */ -static unsigned long p2m_top_mfn[TOP_ENTRIES] __page_aligned_bss; +static RESERVE_BRK_ARRAY(unsigned long **, p2m_top, P2M_TOP_PER_PAGE); +static RESERVE_BRK_ARRAY(unsigned long, p2m_top_mfn, P2M_TOP_PER_PAGE); +static RESERVE_BRK_ARRAY(unsigned long *, p2m_top_mfn_p, P2M_TOP_PER_PAGE); -static unsigned long p2m_top_mfn_list[TOP_ENTRIES / P2M_ENTRIES_PER_PAGE] - __page_aligned_bss; +RESERVE_BRK(p2m_mid, PAGE_SIZE * (MAX_DOMAIN_PAGES / (P2M_PER_PAGE * P2M_MID_PER_PAGE))); +RESERVE_BRK(p2m_mid_mfn, PAGE_SIZE * (MAX_DOMAIN_PAGES / (P2M_PER_PAGE * P2M_MID_PER_PAGE))); static inline unsigned p2m_top_index(unsigned long pfn) { - BUG_ON(pfn >= MAX_DOMAIN_PAGES); - return pfn / P2M_ENTRIES_PER_PAGE; + BUG_ON(pfn >= MAX_P2M_PFN); + return pfn / (P2M_MID_PER_PAGE * P2M_PER_PAGE); +} + +static inline unsigned p2m_mid_index(unsigned long pfn) +{ + return (pfn / P2M_PER_PAGE) % P2M_MID_PER_PAGE; } static inline unsigned p2m_index(unsigned long pfn) { - return pfn % P2M_ENTRIES_PER_PAGE; + return pfn % P2M_PER_PAGE; } -/* Build the parallel p2m_top_mfn structures */ +static void p2m_top_init(unsigned long ***top) +{ + unsigned i; + + for (i = 0; i < P2M_TOP_PER_PAGE; i++) + top[i] = p2m_mid_missing; +} + +static void p2m_top_mfn_init(unsigned long *top) +{ + unsigned i; + + for (i = 0; i < P2M_TOP_PER_PAGE; i++) + top[i] = virt_to_mfn(p2m_mid_missing_mfn); +} + +static void p2m_top_mfn_p_init(unsigned long **top) +{ + unsigned i; + + for (i = 0; i < P2M_TOP_PER_PAGE; i++) + top[i] = p2m_mid_missing_mfn; +} + +static void p2m_mid_init(unsigned long **mid) +{ + unsigned i; + + for (i = 0; i < P2M_MID_PER_PAGE; i++) + mid[i] = p2m_missing; +} + +static void p2m_mid_mfn_init(unsigned long *mid) +{ + unsigned i; + + for (i = 0; i < P2M_MID_PER_PAGE; i++) + mid[i] = virt_to_mfn(p2m_missing); +} + +static void p2m_init(unsigned long *p2m) +{ + unsigned i; + + for (i = 0; i < P2M_MID_PER_PAGE; i++) + p2m[i] = INVALID_P2M_ENTRY; +} + +/* + * Build the parallel p2m_top_mfn and p2m_mid_mfn structures + * + * This is called both at boot time, and after resuming from suspend: + * - At boot time we're called very early, and must use extend_brk() + * to allocate memory. + * + * - After resume we're called from within stop_machine, but the mfn + * tree should alreay be completely allocated. + */ void xen_build_mfn_list_list(void) { - unsigned pfn, idx; + unsigned long pfn; - for (pfn = 0; pfn < MAX_DOMAIN_PAGES; pfn += P2M_ENTRIES_PER_PAGE) { - unsigned topidx = p2m_top_index(pfn); + /* Pre-initialize p2m_top_mfn to be completely missing */ + if (p2m_top_mfn == NULL) { + p2m_mid_missing_mfn = extend_brk(PAGE_SIZE, PAGE_SIZE); + p2m_mid_mfn_init(p2m_mid_missing_mfn); + + p2m_top_mfn_p = extend_brk(PAGE_SIZE, PAGE_SIZE); + p2m_top_mfn_p_init(p2m_top_mfn_p); - p2m_top_mfn[topidx] = virt_to_mfn(p2m_top[topidx]); + p2m_top_mfn = extend_brk(PAGE_SIZE, PAGE_SIZE); + p2m_top_mfn_init(p2m_top_mfn); + } else { + /* Reinitialise, mfn's all change after migration */ + p2m_mid_mfn_init(p2m_mid_missing_mfn); } - for (idx = 0; idx < ARRAY_SIZE(p2m_top_mfn_list); idx++) { - unsigned topidx = idx * P2M_ENTRIES_PER_PAGE; - p2m_top_mfn_list[idx] = virt_to_mfn(&p2m_top_mfn[topidx]); + for (pfn = 0; pfn < xen_max_p2m_pfn; pfn += P2M_PER_PAGE) { + unsigned topidx = p2m_top_index(pfn); + unsigned mididx = p2m_mid_index(pfn); + unsigned long **mid; + unsigned long *mid_mfn_p; + + mid = p2m_top[topidx]; + mid_mfn_p = p2m_top_mfn_p[topidx]; + + /* Don't bother allocating any mfn mid levels if + * they're just missing, just update the stored mfn, + * since all could have changed over a migrate. + */ + if (mid == p2m_mid_missing) { + BUG_ON(mididx); + BUG_ON(mid_mfn_p != p2m_mid_missing_mfn); + p2m_top_mfn[topidx] = virt_to_mfn(p2m_mid_missing_mfn); + pfn += (P2M_MID_PER_PAGE - 1) * P2M_PER_PAGE; + continue; + } + + if (mid_mfn_p == p2m_mid_missing_mfn) { + /* + * XXX boot-time only! We should never find + * missing parts of the mfn tree after + * runtime. extend_brk() will BUG if we call + * it too late. + */ + mid_mfn_p = extend_brk(PAGE_SIZE, PAGE_SIZE); + p2m_mid_mfn_init(mid_mfn_p); + + p2m_top_mfn_p[topidx] = mid_mfn_p; + } + + p2m_top_mfn[topidx] = virt_to_mfn(mid_mfn_p); + mid_mfn_p[mididx] = virt_to_mfn(mid[mididx]); } } @@ -207,8 +357,8 @@ 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_list); - HYPERVISOR_shared_info->arch.max_pfn = xen_start_info->nr_pages; + virt_to_mfn(p2m_top_mfn); + HYPERVISOR_shared_info->arch.max_pfn = xen_max_p2m_pfn; } /* Set up p2m_top to point to the domain-builder provided p2m pages */ @@ -216,98 +366,176 @@ void __init xen_build_dynamic_phys_to_machine(void) { unsigned long *mfn_list = (unsigned long *)xen_start_info->mfn_list; unsigned long max_pfn = min(MAX_DOMAIN_PAGES, xen_start_info->nr_pages); - unsigned pfn; + unsigned long pfn; + + xen_max_p2m_pfn = max_pfn; + + p2m_missing = extend_brk(PAGE_SIZE, PAGE_SIZE); + p2m_init(p2m_missing); - for (pfn = 0; pfn < max_pfn; pfn += P2M_ENTRIES_PER_PAGE) { + p2m_mid_missing = extend_brk(PAGE_SIZE, PAGE_SIZE); + p2m_mid_init(p2m_mid_missing); + + p2m_top = extend_brk(PAGE_SIZE, PAGE_SIZE); + p2m_top_init(p2m_top); + + /* + * The domain builder gives us a pre-constructed p2m array in + * mfn_list for all the pages initially given to us, so we just + * need to graft that into our tree structure. + */ + for (pfn = 0; pfn < max_pfn; pfn += P2M_PER_PAGE) { unsigned topidx = p2m_top_index(pfn); + unsigned mididx = p2m_mid_index(pfn); - p2m_top[topidx] = &mfn_list[pfn]; - } + if (p2m_top[topidx] == p2m_mid_missing) { + unsigned long **mid = extend_brk(PAGE_SIZE, PAGE_SIZE); + p2m_mid_init(mid); - xen_build_mfn_list_list(); + p2m_top[topidx] = mid; + } + + p2m_top[topidx][mididx] = &mfn_list[pfn]; + } } unsigned long get_phys_to_machine(unsigned long pfn) { - unsigned topidx, idx; + unsigned topidx, mididx, idx; - if (unlikely(pfn >= MAX_DOMAIN_PAGES)) + if (unlikely(pfn >= MAX_P2M_PFN)) return INVALID_P2M_ENTRY; topidx = p2m_top_index(pfn); + mididx = p2m_mid_index(pfn); idx = p2m_index(pfn); - return p2m_top[topidx][idx]; + + return p2m_top[topidx][mididx][idx]; } EXPORT_SYMBOL_GPL(get_phys_to_machine); -/* install a new p2m_top page */ -bool install_p2mtop_page(unsigned long pfn, unsigned long *p) +static void *alloc_p2m_page(void) { - unsigned topidx = p2m_top_index(pfn); - unsigned long **pfnp, *mfnp; - unsigned i; + return (void *)__get_free_page(GFP_KERNEL | __GFP_REPEAT); +} - pfnp = &p2m_top[topidx]; - mfnp = &p2m_top_mfn[topidx]; +static void free_p2m_page(void *p) +{ + free_page((unsigned long)p); +} - for (i = 0; i < P2M_ENTRIES_PER_PAGE; i++) - p[i] = INVALID_P2M_ENTRY; +/* + * Fully allocate the p2m structure for a given pfn. We need to check + * that both the top and mid levels are allocated, and make sure the + * parallel mfn tree is kept in sync. We may race with other cpus, so + * 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) +{ + unsigned topidx, mididx; + unsigned long ***top_p, **mid; + unsigned long *top_mfn_p, *mid_mfn; - if (cmpxchg(pfnp, p2m_missing, p) == p2m_missing) { - *mfnp = virt_to_mfn(p); - return true; + topidx = p2m_top_index(pfn); + mididx = p2m_mid_index(pfn); + + top_p = &p2m_top[topidx]; + mid = *top_p; + + if (mid == p2m_mid_missing) { + /* Mid level is missing, allocate a new one */ + mid = alloc_p2m_page(); + if (!mid) + return false; + + p2m_mid_init(mid); + + if (cmpxchg(top_p, p2m_mid_missing, mid) != p2m_mid_missing) + free_p2m_page(mid); } - return false; -} + top_mfn_p = &p2m_top_mfn[topidx]; + mid_mfn = p2m_top_mfn_p[topidx]; -static void alloc_p2m(unsigned long pfn) -{ - unsigned long *p; + BUG_ON(virt_to_mfn(mid_mfn) != *top_mfn_p); + + if (mid_mfn == p2m_mid_missing_mfn) { + /* Separately check the mid mfn level */ + unsigned long missing_mfn; + unsigned long mid_mfn_mfn; + + mid_mfn = alloc_p2m_page(); + if (!mid_mfn) + return false; + + p2m_mid_mfn_init(mid_mfn); + + missing_mfn = virt_to_mfn(p2m_mid_missing_mfn); + mid_mfn_mfn = virt_to_mfn(mid_mfn); + if (cmpxchg(top_mfn_p, missing_mfn, mid_mfn_mfn) != missing_mfn) + free_p2m_page(mid_mfn); + else + p2m_top_mfn_p[topidx] = mid_mfn; + } + + if (p2m_top[topidx][mididx] == p2m_missing) { + /* p2m leaf page is missing */ + unsigned long *p2m; + + p2m = alloc_p2m_page(); + if (!p2m) + return false; + + p2m_init(p2m); - p = (void *)__get_free_page(GFP_KERNEL | __GFP_NOFAIL); - BUG_ON(p == NULL); + if (cmpxchg(&mid[mididx], p2m_missing, p2m) != p2m_missing) + free_p2m_page(p2m); + else + mid_mfn[mididx] = virt_to_mfn(p2m); + } - if (!install_p2mtop_page(pfn, p)) - free_page((unsigned long)p); + return true; } /* Try to install p2m mapping; fail if intermediate bits missing */ bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn) { - unsigned topidx, idx; + unsigned topidx, mididx, idx; - if (unlikely(pfn >= MAX_DOMAIN_PAGES)) { + if (unlikely(pfn >= MAX_P2M_PFN)) { BUG_ON(mfn != INVALID_P2M_ENTRY); return true; } topidx = p2m_top_index(pfn); - if (p2m_top[topidx] == p2m_missing) { - if (mfn == INVALID_P2M_ENTRY) - return true; - return false; - } - + mididx = p2m_mid_index(pfn); idx = p2m_index(pfn); - p2m_top[topidx][idx] = mfn; + + if (p2m_top[topidx][mididx] == p2m_missing) + return mfn == INVALID_P2M_ENTRY; + + p2m_top[topidx][mididx][idx] = mfn; return true; } -void set_phys_to_machine(unsigned long pfn, unsigned long mfn) +bool set_phys_to_machine(unsigned long pfn, unsigned long mfn) { if (unlikely(xen_feature(XENFEAT_auto_translated_physmap))) { BUG_ON(pfn != mfn && mfn != INVALID_P2M_ENTRY); - return; + return true; } if (unlikely(!__set_phys_to_machine(pfn, mfn))) { - alloc_p2m(pfn); + if (!alloc_p2m(pfn)) + return false; if (!__set_phys_to_machine(pfn, mfn)) - BUG(); + return false; } + + return true; } unsigned long arbitrary_virt_to_mfn(void *vaddr) @@ -346,7 +574,8 @@ void make_lowmem_page_readonly(void *vaddr) unsigned int level; pte = lookup_address(address, &level); - BUG_ON(pte == NULL); + if (pte == NULL) + return; /* vaddr missing */ ptev = pte_wrprotect(*pte); @@ -361,7 +590,8 @@ void make_lowmem_page_readwrite(void *vaddr) unsigned int level; pte = lookup_address(address, &level); - BUG_ON(pte == NULL); + if (pte == NULL) + return; /* vaddr missing */ ptev = pte_mkwrite(*pte); @@ -377,6 +607,34 @@ static bool xen_page_pinned(void *ptr) return PagePinned(page); } +static bool xen_iomap_pte(pte_t pte) +{ + return pte_flags(pte) & _PAGE_IOMAP; +} + +void xen_set_domain_pte(pte_t *ptep, pte_t pteval, unsigned domid) +{ + struct multicall_space mcs; + struct mmu_update *u; + + mcs = xen_mc_entry(sizeof(*u)); + u = mcs.args; + + /* ptep might be kmapped when using 32-bit HIGHPTE */ + u->ptr = arbitrary_virt_to_machine(ptep).maddr; + u->val = pte_val_ma(pteval); + + MULTI_mmu_update(mcs.mc, mcs.args, 1, NULL, domid); + + xen_mc_issue(PARAVIRT_LAZY_MMU); +} +EXPORT_SYMBOL_GPL(xen_set_domain_pte); + +static void xen_set_iomap_pte(pte_t *ptep, pte_t pteval) +{ + xen_set_domain_pte(ptep, pteval, DOMID_IO); +} + static void xen_extend_mmu_update(const struct mmu_update *update) { struct multicall_space mcs; @@ -453,6 +711,11 @@ void set_pte_mfn(unsigned long vaddr, unsigned long mfn, pgprot_t flags) void xen_set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pteval) { + if (xen_iomap_pte(pteval)) { + xen_set_iomap_pte(ptep, pteval); + goto out; + } + ADD_STATS(set_pte_at, 1); // ADD_STATS(set_pte_at_pinned, xen_page_pinned(ptep)); ADD_STATS(set_pte_at_current, mm == current->mm); @@ -517,7 +780,34 @@ 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; - val = ((pteval_t)pfn_to_mfn(pfn) << PAGE_SHIFT) | flags; + unsigned long mfn = pfn_to_mfn(pfn); + + /* + * If there's no mfn for the pfn, then just create an + * empty non-present pte. Unfortunately this loses + * information about the original pfn, so + * pte_mfn_to_pfn is asymmetric. + */ + if (unlikely(mfn == INVALID_P2M_ENTRY)) { + mfn = 0; + flags = 0; + } + + val = ((pteval_t)mfn << PAGE_SHIFT) | flags; + } + + return val; +} + +static pteval_t iomap_pte(pteval_t val) +{ + if (val & _PAGE_PRESENT) { + unsigned long pfn = (val & PTE_PFN_MASK) >> PAGE_SHIFT; + pteval_t flags = val & PTE_FLAGS_MASK; + + /* We assume the pte frame number is a MFN, so + just use it as-is. */ + val = ((pteval_t)pfn << PAGE_SHIFT) | flags; } return val; @@ -525,7 +815,18 @@ static pteval_t pte_pfn_to_mfn(pteval_t val) pteval_t xen_pte_val(pte_t pte) { - return pte_mfn_to_pfn(pte.pte); + pteval_t pteval = pte.pte; + + /* If this is a WC pte, convert back from Xen WC to Linux WC */ + if ((pteval & (_PAGE_PAT | _PAGE_PCD | _PAGE_PWT)) == _PAGE_PAT) { + WARN_ON(!pat_enabled); + pteval = (pteval & ~_PAGE_PAT) | _PAGE_PWT; + } + + if (xen_initial_domain() && (pteval & _PAGE_IOMAP)) + return pteval; + + return pte_mfn_to_pfn(pteval); } PV_CALLEE_SAVE_REGS_THUNK(xen_pte_val); @@ -535,9 +836,62 @@ pgdval_t xen_pgd_val(pgd_t pgd) } PV_CALLEE_SAVE_REGS_THUNK(xen_pgd_val); +/* + * Xen's PAT setup is part of its ABI, though I assume entries 6 & 7 + * are reserved for now, to correspond to the Intel-reserved PAT + * types. + * + * We expect Linux's PAT set as follows: + * + * Idx PTE flags Linux Xen Default + * 0 WB WB WB + * 1 PWT WC WT WT + * 2 PCD UC- UC- UC- + * 3 PCD PWT UC UC UC + * 4 PAT WB WC WB + * 5 PAT PWT WC WP WT + * 6 PAT PCD UC- UC UC- + * 7 PAT PCD PWT UC UC UC + */ + +void xen_set_pat(u64 pat) +{ + /* We expect Linux to use a PAT setting of + * UC UC- WC WB (ignoring the PAT flag) */ + WARN_ON(pat != 0x0007010600070106ull); +} + pte_t xen_make_pte(pteval_t pte) { - pte = pte_pfn_to_mfn(pte); + phys_addr_t addr = (pte & PTE_PFN_MASK); + + /* If Linux is trying to set a WC pte, then map to the Xen WC. + * If _PAGE_PAT is set, then it probably means it is really + * _PAGE_PSE, so avoid fiddling with the PAT mapping and hope + * things work out OK... + * + * (We should never see kernel mappings with _PAGE_PSE set, + * but we could see hugetlbfs mappings, I think.). + */ + if (pat_enabled && !WARN_ON(pte & _PAGE_PAT)) { + if ((pte & (_PAGE_PCD | _PAGE_PWT)) == _PAGE_PWT) + pte = (pte & ~(_PAGE_PCD | _PAGE_PWT)) | _PAGE_PAT; + } + + /* + * Unprivileged domains are allowed to do IOMAPpings for + * PCI passthrough, but not map ISA space. The ISA + * mappings are just dummy local mappings to keep other + * parts of the kernel happy. + */ + if (unlikely(pte & _PAGE_IOMAP) && + (xen_initial_domain() || addr >= ISA_END_ADDRESS)) { + pte = iomap_pte(pte); + } else { + pte &= ~_PAGE_IOMAP; + pte = pte_pfn_to_mfn(pte); + } + return native_make_pte(pte); } PV_CALLEE_SAVE_REGS_THUNK(xen_make_pte); @@ -593,6 +947,11 @@ void xen_set_pud(pud_t *ptr, pud_t val) void xen_set_pte(pte_t *ptep, pte_t pte) { + if (xen_iomap_pte(pte)) { + xen_set_iomap_pte(ptep, pte); + return; + } + ADD_STATS(pte_update, 1); // ADD_STATS(pte_update_pinned, xen_page_pinned(ptep)); ADD_STATS(pte_update_batched, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU); @@ -609,6 +968,11 @@ void xen_set_pte(pte_t *ptep, pte_t pte) #ifdef CONFIG_X86_PAE void xen_set_pte_atomic(pte_t *ptep, pte_t pte) { + if (xen_iomap_pte(pte)) { + xen_set_iomap_pte(ptep, pte); + return; + } + set_64bit((u64 *)ptep, native_pte_val(pte)); } @@ -935,8 +1299,6 @@ static int xen_pin_page(struct mm_struct *mm, struct page *page, read-only, and can be pinned. */ static void __xen_pgd_pin(struct mm_struct *mm, pgd_t *pgd) { - vm_unmap_aliases(); - xen_mc_batch(); if (__xen_pgd_walk(mm, pgd, xen_pin_page, USER_LIMIT)) { @@ -1428,13 +1790,25 @@ static void xen_pgd_free(struct mm_struct *mm, pgd_t *pgd) #endif } -#ifdef CONFIG_X86_32 static __init pte_t mask_rw_pte(pte_t *ptep, pte_t pte) { + unsigned long pfn = pte_pfn(pte); + +#ifdef CONFIG_X86_32 /* If there's an existing pte, then don't allow _PAGE_RW to be set */ if (pte_val_ma(*ptep) & _PAGE_PRESENT) pte = __pte_ma(((pte_val_ma(*ptep) & _PAGE_RW) | ~_PAGE_RW) & pte_val_ma(pte)); +#endif + + /* + * If the new pfn is within the range of the newly allocated + * kernel pagetable, and it isn't being mapped into an + * early_ioremap fixmap slot, make sure it is RO. + */ + if (!is_early_ioremap_ptep(ptep) && + pfn >= e820_table_start && pfn < e820_table_end) + pte = pte_wrprotect(pte); return pte; } @@ -1447,7 +1821,6 @@ static __init void xen_set_pte_init(pte_t *ptep, pte_t pte) xen_set_pte(ptep, pte); } -#endif static void pin_pagetable_pfn(unsigned cmd, unsigned long pfn) { @@ -1500,7 +1873,6 @@ static void xen_alloc_ptpage(struct mm_struct *mm, unsigned long pfn, unsigned l if (PagePinned(virt_to_page(mm->pgd))) { SetPagePinned(page); - vm_unmap_aliases(); if (!PageHighMem(page)) { make_lowmem_page_readonly(__va(PFN_PHYS((unsigned long)pfn))); if (level == PT_PTE && USE_SPLIT_PTLOCKS) @@ -1603,6 +1975,7 @@ static void *m2v(phys_addr_t maddr) return __ka(m2p(maddr)); } +/* Set the page permissions on an identity-mapped pages */ static void set_page_prot(void *addr, pgprot_t prot) { unsigned long pfn = __pa(addr) >> PAGE_SHIFT; @@ -1618,6 +1991,9 @@ static __init void xen_map_identity_early(pmd_t *pmd, unsigned long max_pfn) unsigned ident_pte; unsigned long pfn; + level1_ident_pgt = extend_brk(sizeof(pte_t) * LEVEL1_IDENT_ENTRIES, + PAGE_SIZE); + ident_pte = 0; pfn = 0; for (pmdidx = 0; pmdidx < PTRS_PER_PMD && pfn < max_pfn; pmdidx++) { @@ -1628,7 +2004,7 @@ static __init void xen_map_identity_early(pmd_t *pmd, unsigned long max_pfn) pte_page = m2v(pmd[pmdidx].pmd); else { /* Check for free pte pages */ - if (ident_pte == ARRAY_SIZE(level1_ident_pgt)) + if (ident_pte == LEVEL1_IDENT_ENTRIES) break; pte_page = &level1_ident_pgt[ident_pte]; @@ -1735,7 +2111,7 @@ __init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd, __xen_write_cr3(true, __pa(pgd)); xen_mc_issue(PARAVIRT_LAZY_CPU); - reserve_early(__pa(xen_start_info->pt_base), + memblock_x86_reserve_range(__pa(xen_start_info->pt_base), __pa(xen_start_info->pt_base + xen_start_info->nr_pt_frames * PAGE_SIZE), "XEN PAGETABLES"); @@ -1743,13 +2119,15 @@ __init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd, return pgd; } #else /* !CONFIG_X86_64 */ -static pmd_t level2_kernel_pgt[PTRS_PER_PMD] __page_aligned_bss; +static RESERVE_BRK_ARRAY(pmd_t, level2_kernel_pgt, PTRS_PER_PMD); __init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn) { pmd_t *kernel_pmd; + level2_kernel_pgt = extend_brk(sizeof(pmd_t *) * PTRS_PER_PMD, PAGE_SIZE); + max_pfn_mapped = PFN_DOWN(__pa(xen_start_info->pt_base) + xen_start_info->nr_pt_frames * PAGE_SIZE + 512*1024); @@ -1773,7 +2151,7 @@ __init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd, pin_pagetable_pfn(MMUEXT_PIN_L3_TABLE, PFN_DOWN(__pa(swapper_pg_dir))); - reserve_early(__pa(xen_start_info->pt_base), + memblock_x86_reserve_range(__pa(xen_start_info->pt_base), __pa(xen_start_info->pt_base + xen_start_info->nr_pt_frames * PAGE_SIZE), "XEN PAGETABLES"); @@ -1782,6 +2160,8 @@ __init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd, } #endif /* CONFIG_X86_64 */ +static unsigned char dummy_mapping[PAGE_SIZE] __page_aligned_bss; + static void xen_set_fixmap(unsigned idx, phys_addr_t phys, pgprot_t prot) { pte_t pte; @@ -1802,18 +2182,38 @@ static void xen_set_fixmap(unsigned idx, phys_addr_t phys, pgprot_t prot) #else case VSYSCALL_LAST_PAGE ... VSYSCALL_FIRST_PAGE: #endif -#ifdef CONFIG_X86_LOCAL_APIC - case FIX_APIC_BASE: /* maps dummy local APIC */ -#endif case FIX_TEXT_POKE0: case FIX_TEXT_POKE1: /* All local page mappings */ pte = pfn_pte(phys, prot); break; - default: +#ifdef CONFIG_X86_LOCAL_APIC + case FIX_APIC_BASE: /* maps dummy local APIC */ + pte = pfn_pte(PFN_DOWN(__pa(dummy_mapping)), PAGE_KERNEL); + break; +#endif + +#ifdef CONFIG_X86_IO_APIC + case FIX_IO_APIC_BASE_0 ... FIX_IO_APIC_BASE_END: + /* + * We just don't map the IO APIC - all access is via + * hypercalls. Keep the address in the pte for reference. + */ + pte = pfn_pte(PFN_DOWN(__pa(dummy_mapping)), PAGE_KERNEL); + break; +#endif + + case FIX_PARAVIRT_BOOTMAP: + /* This is an MFN, but it isn't an IO mapping from the + IO domain */ pte = mfn_pte(phys, prot); break; + + default: + /* By default, set_fixmap is used for hardware mappings */ + pte = mfn_pte(phys, __pgprot(pgprot_val(prot) | _PAGE_IOMAP)); + break; } __native_set_fixmap(idx, pte); @@ -1828,6 +2228,29 @@ static void xen_set_fixmap(unsigned idx, phys_addr_t phys, pgprot_t prot) #endif } +__init void xen_ident_map_ISA(void) +{ + unsigned long pa; + + /* + * If we're dom0, then linear map the ISA machine addresses into + * the kernel's address space. + */ + if (!xen_initial_domain()) + return; + + xen_raw_printk("Xen: setup ISA identity maps\n"); + + for (pa = ISA_START_ADDRESS; pa < ISA_END_ADDRESS; pa += PAGE_SIZE) { + pte_t pte = mfn_pte(PFN_DOWN(pa), PAGE_KERNEL_IO); + + if (HYPERVISOR_update_va_mapping(PAGE_OFFSET + pa, pte, 0)) + BUG(); + } + + xen_flush_tlb(); +} + static __init void xen_post_allocator_init(void) { pv_mmu_ops.set_pte = xen_set_pte; @@ -1883,14 +2306,9 @@ static const struct pv_mmu_ops xen_mmu_ops __initdata = { .alloc_pte = xen_alloc_pte_init, .release_pte = xen_release_pte_init, .alloc_pmd = xen_alloc_pmd_init, - .alloc_pmd_clone = paravirt_nop, .release_pmd = xen_release_pmd_init, -#ifdef CONFIG_X86_64 - .set_pte = xen_set_pte, -#else .set_pte = xen_set_pte_init, -#endif .set_pte_at = xen_set_pte_at, .set_pmd = xen_set_pmd_hyper, @@ -1939,7 +2357,307 @@ void __init xen_init_mmu_ops(void) x86_init.paging.pagetable_setup_start = xen_pagetable_setup_start; x86_init.paging.pagetable_setup_done = xen_pagetable_setup_done; pv_mmu_ops = xen_mmu_ops; + + vmap_lazy_unmap = false; + + memset(dummy_mapping, 0xff, PAGE_SIZE); +} + +/* Protected by xen_reservation_lock. */ +#define MAX_CONTIG_ORDER 9 /* 2MB */ +static unsigned long discontig_frames[1<<MAX_CONTIG_ORDER]; + +#define VOID_PTE (mfn_pte(0, __pgprot(0))) +static void xen_zap_pfn_range(unsigned long vaddr, unsigned int order, + unsigned long *in_frames, + unsigned long *out_frames) +{ + int i; + struct multicall_space mcs; + + xen_mc_batch(); + for (i = 0; i < (1UL<<order); i++, vaddr += PAGE_SIZE) { + mcs = __xen_mc_entry(0); + + if (in_frames) + 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); + + if (out_frames) + out_frames[i] = virt_to_pfn(vaddr); + } + xen_mc_issue(0); +} + +/* + * Update the pfn-to-mfn mappings for a virtual address range, either to + * point to an array of mfns, or contiguously from a single starting + * mfn. + */ +static void xen_remap_exchanged_ptes(unsigned long vaddr, int order, + unsigned long *mfns, + unsigned long first_mfn) +{ + unsigned i, limit; + unsigned long mfn; + + xen_mc_batch(); + + limit = 1u << order; + for (i = 0; i < limit; i++, vaddr += PAGE_SIZE) { + struct multicall_space mcs; + unsigned flags; + + mcs = __xen_mc_entry(0); + if (mfns) + mfn = mfns[i]; + else + mfn = first_mfn + i; + + if (i < (limit - 1)) + flags = 0; + else { + if (order == 0) + flags = UVMF_INVLPG | UVMF_ALL; + else + flags = UVMF_TLB_FLUSH | UVMF_ALL; + } + + MULTI_update_va_mapping(mcs.mc, vaddr, + mfn_pte(mfn, PAGE_KERNEL), flags); + + set_phys_to_machine(virt_to_pfn(vaddr), mfn); + } + + xen_mc_issue(0); +} + +/* + * Perform the hypercall to exchange a region of our pfns to point to + * memory with the required contiguous alignment. Takes the pfns as + * input, and populates mfns as output. + * + * Returns a success code indicating whether the hypervisor was able to + * satisfy the request or not. + */ +static int xen_exchange_memory(unsigned long extents_in, unsigned int order_in, + unsigned long *pfns_in, + unsigned long extents_out, + unsigned int order_out, + unsigned long *mfns_out, + unsigned int address_bits) +{ + long rc; + int success; + + struct xen_memory_exchange exchange = { + .in = { + .nr_extents = extents_in, + .extent_order = order_in, + .extent_start = pfns_in, + .domid = DOMID_SELF + }, + .out = { + .nr_extents = extents_out, + .extent_order = order_out, + .extent_start = mfns_out, + .address_bits = address_bits, + .domid = DOMID_SELF + } + }; + + BUG_ON(extents_in << order_in != extents_out << order_out); + + rc = HYPERVISOR_memory_op(XENMEM_exchange, &exchange); + success = (exchange.nr_exchanged == extents_in); + + BUG_ON(!success && ((exchange.nr_exchanged != 0) || (rc == 0))); + BUG_ON(success && (rc != 0)); + + return success; +} + +int xen_create_contiguous_region(unsigned long vstart, unsigned int order, + unsigned int address_bits) +{ + unsigned long *in_frames = discontig_frames, out_frame; + unsigned long flags; + int success; + + /* + * Currently an auto-translated guest will not perform I/O, nor will + * it require PAE page directories below 4GB. Therefore any calls to + * this function are redundant and can be ignored. + */ + + if (xen_feature(XENFEAT_auto_translated_physmap)) + return 0; + + if (unlikely(order > MAX_CONTIG_ORDER)) + return -ENOMEM; + + memset((void *) vstart, 0, PAGE_SIZE << order); + + spin_lock_irqsave(&xen_reservation_lock, flags); + + /* 1. Zap current PTEs, remembering MFNs. */ + xen_zap_pfn_range(vstart, order, in_frames, NULL); + + /* 2. Get a new contiguous memory extent. */ + out_frame = virt_to_pfn(vstart); + success = xen_exchange_memory(1UL << order, 0, in_frames, + 1, order, &out_frame, + address_bits); + + /* 3. Map the new extent in place of old pages. */ + if (success) + xen_remap_exchanged_ptes(vstart, order, NULL, out_frame); + else + xen_remap_exchanged_ptes(vstart, order, in_frames, 0); + + spin_unlock_irqrestore(&xen_reservation_lock, flags); + + return success ? 0 : -ENOMEM; +} +EXPORT_SYMBOL_GPL(xen_create_contiguous_region); + +void xen_destroy_contiguous_region(unsigned long vstart, unsigned int order) +{ + unsigned long *out_frames = discontig_frames, in_frame; + unsigned long flags; + int success; + + if (xen_feature(XENFEAT_auto_translated_physmap)) + return; + + if (unlikely(order > MAX_CONTIG_ORDER)) + return; + + memset((void *) vstart, 0, PAGE_SIZE << order); + + spin_lock_irqsave(&xen_reservation_lock, flags); + + /* 1. Find start MFN of contiguous extent. */ + in_frame = virt_to_mfn(vstart); + + /* 2. Zap current PTEs. */ + xen_zap_pfn_range(vstart, order, NULL, out_frames); + + /* 3. Do the exchange for non-contiguous MFNs. */ + success = xen_exchange_memory(1, order, &in_frame, 1UL << order, + 0, out_frames, 0); + + /* 4. Map new pages in place of old pages. */ + if (success) + xen_remap_exchanged_ptes(vstart, order, out_frames, 0); + else + xen_remap_exchanged_ptes(vstart, order, NULL, in_frame); + + spin_unlock_irqrestore(&xen_reservation_lock, flags); +} +EXPORT_SYMBOL_GPL(xen_destroy_contiguous_region); + +#ifdef CONFIG_XEN_PVHVM +static void xen_hvm_exit_mmap(struct mm_struct *mm) +{ + struct xen_hvm_pagetable_dying a; + int rc; + + a.domid = DOMID_SELF; + a.gpa = __pa(mm->pgd); + rc = HYPERVISOR_hvm_op(HVMOP_pagetable_dying, &a); + WARN_ON_ONCE(rc < 0); +} + +static int is_pagetable_dying_supported(void) +{ + struct xen_hvm_pagetable_dying a; + int rc = 0; + + a.domid = DOMID_SELF; + a.gpa = 0x00; + rc = HYPERVISOR_hvm_op(HVMOP_pagetable_dying, &a); + if (rc < 0) { + printk(KERN_DEBUG "HVMOP_pagetable_dying not supported\n"); + return 0; + } + return 1; +} + +void __init xen_hvm_init_mmu_ops(void) +{ + if (is_pagetable_dying_supported()) + pv_mmu_ops.exit_mmap = xen_hvm_exit_mmap; +} +#endif + +#define REMAP_BATCH_SIZE 16 + +struct remap_data { + unsigned long mfn; + pgprot_t prot; + struct mmu_update *mmu_update; +}; + +static int remap_area_mfn_pte_fn(pte_t *ptep, pgtable_t token, + unsigned long addr, void *data) +{ + struct remap_data *rmd = data; + pte_t pte = pte_mkspecial(pfn_pte(rmd->mfn++, rmd->prot)); + + rmd->mmu_update->ptr = arbitrary_virt_to_machine(ptep).maddr; + rmd->mmu_update->val = pte_val_ma(pte); + rmd->mmu_update++; + + return 0; +} + +int xen_remap_domain_mfn_range(struct vm_area_struct *vma, + unsigned long addr, + unsigned long mfn, int nr, + pgprot_t prot, unsigned domid) +{ + struct remap_data rmd; + struct mmu_update mmu_update[REMAP_BATCH_SIZE]; + int batch; + unsigned long range; + int err = 0; + + prot = __pgprot(pgprot_val(prot) | _PAGE_IOMAP); + + vma->vm_flags |= VM_IO | VM_RESERVED | VM_PFNMAP; + + rmd.mfn = mfn; + rmd.prot = prot; + + while (nr) { + batch = min(REMAP_BATCH_SIZE, nr); + range = (unsigned long)batch << PAGE_SHIFT; + + rmd.mmu_update = mmu_update; + err = apply_to_page_range(vma->vm_mm, addr, range, + remap_area_mfn_pte_fn, &rmd); + if (err) + goto out; + + err = -EFAULT; + if (HYPERVISOR_mmu_update(mmu_update, batch, NULL, domid) < 0) + goto out; + + nr -= batch; + addr += range; + } + + err = 0; +out: + + flush_tlb_all(); + + return err; } +EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range); #ifdef CONFIG_XEN_DEBUG_FS |