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https://github.com/torvalds/linux.git
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Merge branches 'stable/p2m-identity.v4.9.1' and 'stable/e820' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
* 'stable/p2m-identity.v4.9.1' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen/m2p: Check whether the MFN has IDENTITY_FRAME bit set.. xen/m2p: No need to catch exceptions when we know that there is no RAM xen/debug: WARN_ON when identity PFN has no _PAGE_IOMAP flag set. xen/debugfs: Add 'p2m' file for printing out the P2M layout. xen/setup: Set identity mapping for non-RAM E820 and E820 gaps. xen/mmu: WARN_ON when racing to swap middle leaf. xen/mmu: Set _PAGE_IOMAP if PFN is an identity PFN. xen/mmu: Add the notion of identity (1-1) mapping. xen: Mark all initial reserved pages for the balloon as INVALID_P2M_ENTRY. * 'stable/e820' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen/e820: Don't mark balloon memory as E820_UNUSABLE when running as guest and fix overflow. xen/setup: Inhibit resource API from using System RAM E820 gaps as PCI mem gaps.
This commit is contained in:
Linus Torvalds
commit
c7146dd009
@ -29,8 +29,10 @@ typedef struct xpaddr {
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/**** MACHINE <-> PHYSICAL CONVERSION MACROS ****/
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#define INVALID_P2M_ENTRY (~0UL)
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#define FOREIGN_FRAME_BIT (1UL<<31)
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#define FOREIGN_FRAME_BIT (1UL<<(BITS_PER_LONG-1))
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#define IDENTITY_FRAME_BIT (1UL<<(BITS_PER_LONG-2))
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#define FOREIGN_FRAME(m) ((m) | FOREIGN_FRAME_BIT)
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#define IDENTITY_FRAME(m) ((m) | IDENTITY_FRAME_BIT)
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/* Maximum amount of memory we can handle in a domain in pages */
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#define MAX_DOMAIN_PAGES \
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@ -41,12 +43,18 @@ extern unsigned int machine_to_phys_order;
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extern unsigned long get_phys_to_machine(unsigned long pfn);
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extern bool set_phys_to_machine(unsigned long pfn, unsigned long mfn);
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extern bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn);
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extern unsigned long set_phys_range_identity(unsigned long pfn_s,
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unsigned long pfn_e);
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extern int m2p_add_override(unsigned long mfn, struct page *page);
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extern int m2p_remove_override(struct page *page);
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extern struct page *m2p_find_override(unsigned long mfn);
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extern unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn);
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#ifdef CONFIG_XEN_DEBUG_FS
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extern int p2m_dump_show(struct seq_file *m, void *v);
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#endif
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static inline unsigned long pfn_to_mfn(unsigned long pfn)
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{
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unsigned long mfn;
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@ -57,7 +65,7 @@ static inline unsigned long pfn_to_mfn(unsigned long pfn)
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mfn = get_phys_to_machine(pfn);
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if (mfn != INVALID_P2M_ENTRY)
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mfn &= ~FOREIGN_FRAME_BIT;
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mfn &= ~(FOREIGN_FRAME_BIT | IDENTITY_FRAME_BIT);
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return mfn;
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}
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@ -73,25 +81,44 @@ static inline int phys_to_machine_mapping_valid(unsigned long pfn)
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static inline unsigned long mfn_to_pfn(unsigned long mfn)
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{
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unsigned long pfn;
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int ret = 0;
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if (xen_feature(XENFEAT_auto_translated_physmap))
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return mfn;
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if (unlikely((mfn >> machine_to_phys_order) != 0)) {
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pfn = ~0;
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goto try_override;
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}
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pfn = 0;
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/*
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* The array access can fail (e.g., device space beyond end of RAM).
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* In such cases it doesn't matter what we return (we return garbage),
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* but we must handle the fault without crashing!
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*/
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__get_user(pfn, &machine_to_phys_mapping[mfn]);
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ret = __get_user(pfn, &machine_to_phys_mapping[mfn]);
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try_override:
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/* ret might be < 0 if there are no entries in the m2p for mfn */
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if (ret < 0)
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pfn = ~0;
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else if (get_phys_to_machine(pfn) != mfn)
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/*
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* If this appears to be a foreign mfn (because the pfn
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* doesn't map back to the mfn), then check the local override
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* table to see if there's a better pfn to use.
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*
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* m2p_find_override_pfn returns ~0 if it doesn't find anything.
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*/
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pfn = m2p_find_override_pfn(mfn, ~0);
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/*
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* If this appears to be a foreign mfn (because the pfn
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* doesn't map back to the mfn), then check the local override
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* table to see if there's a better pfn to use.
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/*
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* pfn is ~0 if there are no entries in the m2p for mfn or if the
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* entry doesn't map back to the mfn and m2p_override doesn't have a
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* valid entry for it.
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*/
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if (get_phys_to_machine(pfn) != mfn)
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pfn = m2p_find_override_pfn(mfn, pfn);
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if (pfn == ~0 &&
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get_phys_to_machine(mfn) == IDENTITY_FRAME(mfn))
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pfn = mfn;
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return pfn;
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}
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@ -48,3 +48,11 @@ config XEN_DEBUG_FS
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help
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Enable statistics output and various tuning options in debugfs.
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Enabling this option may incur a significant performance overhead.
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config XEN_DEBUG
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bool "Enable Xen debug checks"
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depends on XEN
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default n
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help
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Enable various WARN_ON checks in the Xen MMU code.
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Enabling this option WILL incur a significant performance overhead.
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@ -46,6 +46,7 @@
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#include <linux/module.h>
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#include <linux/gfp.h>
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#include <linux/memblock.h>
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#include <linux/seq_file.h>
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#include <asm/pgtable.h>
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#include <asm/tlbflush.h>
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@ -416,8 +417,12 @@ static pteval_t pte_pfn_to_mfn(pteval_t val)
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if (val & _PAGE_PRESENT) {
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unsigned long pfn = (val & PTE_PFN_MASK) >> PAGE_SHIFT;
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pteval_t flags = val & PTE_FLAGS_MASK;
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unsigned long mfn = pfn_to_mfn(pfn);
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unsigned long mfn;
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if (!xen_feature(XENFEAT_auto_translated_physmap))
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mfn = get_phys_to_machine(pfn);
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else
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mfn = pfn;
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/*
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* If there's no mfn for the pfn, then just create an
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* empty non-present pte. Unfortunately this loses
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@ -427,8 +432,18 @@ static pteval_t pte_pfn_to_mfn(pteval_t val)
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if (unlikely(mfn == INVALID_P2M_ENTRY)) {
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mfn = 0;
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flags = 0;
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} else {
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/*
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* Paramount to do this test _after_ the
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* INVALID_P2M_ENTRY as INVALID_P2M_ENTRY &
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* IDENTITY_FRAME_BIT resolves to true.
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*/
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mfn &= ~FOREIGN_FRAME_BIT;
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if (mfn & IDENTITY_FRAME_BIT) {
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mfn &= ~IDENTITY_FRAME_BIT;
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flags |= _PAGE_IOMAP;
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}
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}
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val = ((pteval_t)mfn << PAGE_SHIFT) | flags;
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}
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@ -532,6 +547,41 @@ pte_t xen_make_pte(pteval_t pte)
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}
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PV_CALLEE_SAVE_REGS_THUNK(xen_make_pte);
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#ifdef CONFIG_XEN_DEBUG
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pte_t xen_make_pte_debug(pteval_t pte)
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{
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phys_addr_t addr = (pte & PTE_PFN_MASK);
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phys_addr_t other_addr;
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bool io_page = false;
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pte_t _pte;
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if (pte & _PAGE_IOMAP)
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io_page = true;
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_pte = xen_make_pte(pte);
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if (!addr)
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return _pte;
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if (io_page &&
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(xen_initial_domain() || addr >= ISA_END_ADDRESS)) {
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other_addr = pfn_to_mfn(addr >> PAGE_SHIFT) << PAGE_SHIFT;
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WARN(addr != other_addr,
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"0x%lx is using VM_IO, but it is 0x%lx!\n",
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(unsigned long)addr, (unsigned long)other_addr);
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} else {
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pteval_t iomap_set = (_pte.pte & PTE_FLAGS_MASK) & _PAGE_IOMAP;
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other_addr = (_pte.pte & PTE_PFN_MASK);
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WARN((addr == other_addr) && (!io_page) && (!iomap_set),
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"0x%lx is missing VM_IO (and wasn't fixed)!\n",
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(unsigned long)addr);
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}
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return _pte;
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}
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PV_CALLEE_SAVE_REGS_THUNK(xen_make_pte_debug);
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#endif
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pgd_t xen_make_pgd(pgdval_t pgd)
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{
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pgd = pte_pfn_to_mfn(pgd);
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@ -1940,6 +1990,9 @@ __init void xen_ident_map_ISA(void)
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static __init void xen_post_allocator_init(void)
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{
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#ifdef CONFIG_XEN_DEBUG
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pv_mmu_ops.make_pte = PV_CALLEE_SAVE(xen_make_pte_debug);
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#endif
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pv_mmu_ops.set_pte = xen_set_pte;
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pv_mmu_ops.set_pmd = xen_set_pmd;
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pv_mmu_ops.set_pud = xen_set_pud;
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@ -2072,7 +2125,7 @@ static void xen_zap_pfn_range(unsigned long vaddr, unsigned int order,
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in_frames[i] = virt_to_mfn(vaddr);
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MULTI_update_va_mapping(mcs.mc, vaddr, VOID_PTE, 0);
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set_phys_to_machine(virt_to_pfn(vaddr), INVALID_P2M_ENTRY);
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__set_phys_to_machine(virt_to_pfn(vaddr), INVALID_P2M_ENTRY);
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if (out_frames)
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out_frames[i] = virt_to_pfn(vaddr);
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@ -2351,6 +2404,18 @@ EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range);
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#ifdef CONFIG_XEN_DEBUG_FS
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static int p2m_dump_open(struct inode *inode, struct file *filp)
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{
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return single_open(filp, p2m_dump_show, NULL);
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}
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static const struct file_operations p2m_dump_fops = {
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.open = p2m_dump_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = single_release,
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};
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static struct dentry *d_mmu_debug;
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static int __init xen_mmu_debugfs(void)
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@ -2406,6 +2471,7 @@ static int __init xen_mmu_debugfs(void)
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debugfs_create_u32("prot_commit_batched", 0444, d_mmu_debug,
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&mmu_stats.prot_commit_batched);
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debugfs_create_file("p2m", 0600, d_mmu_debug, NULL, &p2m_dump_fops);
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return 0;
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}
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fs_initcall(xen_mmu_debugfs);
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@ -23,6 +23,129 @@
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* P2M_PER_PAGE depends on the architecture, as a mfn is always
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* unsigned long (8 bytes on 64-bit, 4 bytes on 32), leading to
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* 512 and 1024 entries respectively.
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*
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* In short, these structures contain the Machine Frame Number (MFN) of the PFN.
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*
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* However not all entries are filled with MFNs. Specifically for all other
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* leaf entries, or for the top root, or middle one, for which there is a void
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* entry, we assume it is "missing". So (for example)
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* pfn_to_mfn(0x90909090)=INVALID_P2M_ENTRY.
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*
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* We also have the possibility of setting 1-1 mappings on certain regions, so
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* that:
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* pfn_to_mfn(0xc0000)=0xc0000
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*
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* The benefit of this is, that we can assume for non-RAM regions (think
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* PCI BARs, or ACPI spaces), we can create mappings easily b/c we
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* get the PFN value to match the MFN.
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*
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* For this to work efficiently we have one new page p2m_identity and
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* allocate (via reserved_brk) any other pages we need to cover the sides
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* (1GB or 4MB boundary violations). All entries in p2m_identity are set to
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* INVALID_P2M_ENTRY type (Xen toolstack only recognizes that and MFNs,
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* no other fancy value).
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*
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* On lookup we spot that the entry points to p2m_identity and return the
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* identity value instead of dereferencing and returning INVALID_P2M_ENTRY.
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* If the entry points to an allocated page, we just proceed as before and
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* return the PFN. If the PFN has IDENTITY_FRAME_BIT set we unmask that in
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* appropriate functions (pfn_to_mfn).
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*
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* The reason for having the IDENTITY_FRAME_BIT instead of just returning the
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* PFN is that we could find ourselves where pfn_to_mfn(pfn)==pfn for a
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* non-identity pfn. To protect ourselves against we elect to set (and get) the
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* IDENTITY_FRAME_BIT on all identity mapped PFNs.
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*
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* This simplistic diagram is used to explain the more subtle piece of code.
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* There is also a digram of the P2M at the end that can help.
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* Imagine your E820 looking as so:
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*
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* 1GB 2GB
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* /-------------------+---------\/----\ /----------\ /---+-----\
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* | System RAM | Sys RAM ||ACPI| | reserved | | Sys RAM |
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* \-------------------+---------/\----/ \----------/ \---+-----/
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* ^- 1029MB ^- 2001MB
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*
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* [1029MB = 263424 (0x40500), 2001MB = 512256 (0x7D100),
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* 2048MB = 524288 (0x80000)]
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*
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* And dom0_mem=max:3GB,1GB is passed in to the guest, meaning memory past 1GB
|
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* is actually not present (would have to kick the balloon driver to put it in).
|
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*
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* When we are told to set the PFNs for identity mapping (see patch: "xen/setup:
|
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* Set identity mapping for non-RAM E820 and E820 gaps.") we pass in the start
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* of the PFN and the end PFN (263424 and 512256 respectively). The first step
|
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* is to reserve_brk a top leaf page if the p2m[1] is missing. The top leaf page
|
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* covers 512^2 of page estate (1GB) and in case the start or end PFN is not
|
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* aligned on 512^2*PAGE_SIZE (1GB) we loop on aligned 1GB PFNs from start pfn
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* to end pfn. We reserve_brk top leaf pages if they are missing (means they
|
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* point to p2m_mid_missing).
|
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*
|
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* With the E820 example above, 263424 is not 1GB aligned so we allocate a
|
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* reserve_brk page which will cover the PFNs estate from 0x40000 to 0x80000.
|
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* Each entry in the allocate page is "missing" (points to p2m_missing).
|
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*
|
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* Next stage is to determine if we need to do a more granular boundary check
|
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* on the 4MB (or 2MB depending on architecture) off the start and end pfn's.
|
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* We check if the start pfn and end pfn violate that boundary check, and if
|
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* so reserve_brk a middle (p2m[x][y]) leaf page. This way we have a much finer
|
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* granularity of setting which PFNs are missing and which ones are identity.
|
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* In our example 263424 and 512256 both fail the check so we reserve_brk two
|
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* pages. Populate them with INVALID_P2M_ENTRY (so they both have "missing"
|
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* values) and assign them to p2m[1][2] and p2m[1][488] respectively.
|
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*
|
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* At this point we would at minimum reserve_brk one page, but could be up to
|
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* three. Each call to set_phys_range_identity has at maximum a three page
|
||||
* cost. If we were to query the P2M at this stage, all those entries from
|
||||
* start PFN through end PFN (so 1029MB -> 2001MB) would return
|
||||
* INVALID_P2M_ENTRY ("missing").
|
||||
*
|
||||
* The next step is to walk from the start pfn to the end pfn setting
|
||||
* the IDENTITY_FRAME_BIT on each PFN. This is done in set_phys_range_identity.
|
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* If we find that the middle leaf is pointing to p2m_missing we can swap it
|
||||
* over to p2m_identity - this way covering 4MB (or 2MB) PFN space. At this
|
||||
* point we do not need to worry about boundary aligment (so no need to
|
||||
* reserve_brk a middle page, figure out which PFNs are "missing" and which
|
||||
* ones are identity), as that has been done earlier. If we find that the
|
||||
* middle leaf is not occupied by p2m_identity or p2m_missing, we dereference
|
||||
* that page (which covers 512 PFNs) and set the appropriate PFN with
|
||||
* IDENTITY_FRAME_BIT. In our example 263424 and 512256 end up there, and we
|
||||
* set from p2m[1][2][256->511] and p2m[1][488][0->256] with
|
||||
* IDENTITY_FRAME_BIT set.
|
||||
*
|
||||
* All other regions that are void (or not filled) either point to p2m_missing
|
||||
* (considered missing) or have the default value of INVALID_P2M_ENTRY (also
|
||||
* considered missing). In our case, p2m[1][2][0->255] and p2m[1][488][257->511]
|
||||
* contain the INVALID_P2M_ENTRY value and are considered "missing."
|
||||
*
|
||||
* This is what the p2m ends up looking (for the E820 above) with this
|
||||
* fabulous drawing:
|
||||
*
|
||||
* p2m /--------------\
|
||||
* /-----\ | &mfn_list[0],| /-----------------\
|
||||
* | 0 |------>| &mfn_list[1],| /---------------\ | ~0, ~0, .. |
|
||||
* |-----| | ..., ~0, ~0 | | ~0, ~0, [x]---+----->| IDENTITY [@256] |
|
||||
* | 1 |---\ \--------------/ | [p2m_identity]+\ | IDENTITY [@257] |
|
||||
* |-----| \ | [p2m_identity]+\\ | .... |
|
||||
* | 2 |--\ \-------------------->| ... | \\ \----------------/
|
||||
* |-----| \ \---------------/ \\
|
||||
* | 3 |\ \ \\ p2m_identity
|
||||
* |-----| \ \-------------------->/---------------\ /-----------------\
|
||||
* | .. +->+ | [p2m_identity]+-->| ~0, ~0, ~0, ... |
|
||||
* \-----/ / | [p2m_identity]+-->| ..., ~0 |
|
||||
* / /---------------\ | .... | \-----------------/
|
||||
* / | IDENTITY[@0] | /-+-[x], ~0, ~0.. |
|
||||
* / | IDENTITY[@256]|<----/ \---------------/
|
||||
* / | ~0, ~0, .... |
|
||||
* | \---------------/
|
||||
* |
|
||||
* p2m_missing p2m_missing
|
||||
* /------------------\ /------------\
|
||||
* | [p2m_mid_missing]+---->| ~0, ~0, ~0 |
|
||||
* | [p2m_mid_missing]+---->| ..., ~0 |
|
||||
* \------------------/ \------------/
|
||||
*
|
||||
* where ~0 is INVALID_P2M_ENTRY. IDENTITY is (PFN | IDENTITY_BIT)
|
||||
*/
|
||||
|
||||
#include <linux/init.h>
|
||||
@ -30,6 +153,7 @@
|
||||
#include <linux/list.h>
|
||||
#include <linux/hash.h>
|
||||
#include <linux/sched.h>
|
||||
#include <linux/seq_file.h>
|
||||
|
||||
#include <asm/cache.h>
|
||||
#include <asm/setup.h>
|
||||
@ -59,9 +183,15 @@ 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 RESERVE_BRK_ARRAY(unsigned long, p2m_identity, P2M_PER_PAGE);
|
||||
|
||||
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)));
|
||||
|
||||
/* We might hit two boundary violations at the start and end, at max each
|
||||
* boundary violation will require three middle nodes. */
|
||||
RESERVE_BRK(p2m_mid_identity, PAGE_SIZE * 2 * 3);
|
||||
|
||||
static inline unsigned p2m_top_index(unsigned long pfn)
|
||||
{
|
||||
BUG_ON(pfn >= MAX_P2M_PFN);
|
||||
@ -221,6 +351,9 @@ void __init xen_build_dynamic_phys_to_machine(void)
|
||||
p2m_top = extend_brk(PAGE_SIZE, PAGE_SIZE);
|
||||
p2m_top_init(p2m_top);
|
||||
|
||||
p2m_identity = extend_brk(PAGE_SIZE, PAGE_SIZE);
|
||||
p2m_init(p2m_identity);
|
||||
|
||||
/*
|
||||
* The domain builder gives us a pre-constructed p2m array in
|
||||
* mfn_list for all the pages initially given to us, so we just
|
||||
@ -266,6 +399,14 @@ unsigned long get_phys_to_machine(unsigned long pfn)
|
||||
mididx = p2m_mid_index(pfn);
|
||||
idx = p2m_index(pfn);
|
||||
|
||||
/*
|
||||
* The INVALID_P2M_ENTRY is filled in both p2m_*identity
|
||||
* and in p2m_*missing, so returning the INVALID_P2M_ENTRY
|
||||
* would be wrong.
|
||||
*/
|
||||
if (p2m_top[topidx][mididx] == p2m_identity)
|
||||
return IDENTITY_FRAME(pfn);
|
||||
|
||||
return p2m_top[topidx][mididx][idx];
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(get_phys_to_machine);
|
||||
@ -335,9 +476,11 @@ static bool alloc_p2m(unsigned long pfn)
|
||||
p2m_top_mfn_p[topidx] = mid_mfn;
|
||||
}
|
||||
|
||||
if (p2m_top[topidx][mididx] == p2m_missing) {
|
||||
if (p2m_top[topidx][mididx] == p2m_identity ||
|
||||
p2m_top[topidx][mididx] == p2m_missing) {
|
||||
/* p2m leaf page is missing */
|
||||
unsigned long *p2m;
|
||||
unsigned long *p2m_orig = p2m_top[topidx][mididx];
|
||||
|
||||
p2m = alloc_p2m_page();
|
||||
if (!p2m)
|
||||
@ -345,7 +488,7 @@ static bool alloc_p2m(unsigned long pfn)
|
||||
|
||||
p2m_init(p2m);
|
||||
|
||||
if (cmpxchg(&mid[mididx], p2m_missing, p2m) != p2m_missing)
|
||||
if (cmpxchg(&mid[mididx], p2m_orig, p2m) != p2m_orig)
|
||||
free_p2m_page(p2m);
|
||||
else
|
||||
mid_mfn[mididx] = virt_to_mfn(p2m);
|
||||
@ -354,11 +497,91 @@ static bool alloc_p2m(unsigned long pfn)
|
||||
return true;
|
||||
}
|
||||
|
||||
bool __early_alloc_p2m(unsigned long pfn)
|
||||
{
|
||||
unsigned topidx, mididx, idx;
|
||||
|
||||
topidx = p2m_top_index(pfn);
|
||||
mididx = p2m_mid_index(pfn);
|
||||
idx = p2m_index(pfn);
|
||||
|
||||
/* Pfff.. No boundary cross-over, lets get out. */
|
||||
if (!idx)
|
||||
return false;
|
||||
|
||||
WARN(p2m_top[topidx][mididx] == p2m_identity,
|
||||
"P2M[%d][%d] == IDENTITY, should be MISSING (or alloced)!\n",
|
||||
topidx, mididx);
|
||||
|
||||
/*
|
||||
* Could be done by xen_build_dynamic_phys_to_machine..
|
||||
*/
|
||||
if (p2m_top[topidx][mididx] != p2m_missing)
|
||||
return false;
|
||||
|
||||
/* Boundary cross-over for the edges: */
|
||||
if (idx) {
|
||||
unsigned long *p2m = extend_brk(PAGE_SIZE, PAGE_SIZE);
|
||||
|
||||
p2m_init(p2m);
|
||||
|
||||
p2m_top[topidx][mididx] = p2m;
|
||||
|
||||
}
|
||||
return idx != 0;
|
||||
}
|
||||
unsigned long set_phys_range_identity(unsigned long pfn_s,
|
||||
unsigned long pfn_e)
|
||||
{
|
||||
unsigned long pfn;
|
||||
|
||||
if (unlikely(pfn_s >= MAX_P2M_PFN || pfn_e >= MAX_P2M_PFN))
|
||||
return 0;
|
||||
|
||||
if (unlikely(xen_feature(XENFEAT_auto_translated_physmap)))
|
||||
return pfn_e - pfn_s;
|
||||
|
||||
if (pfn_s > pfn_e)
|
||||
return 0;
|
||||
|
||||
for (pfn = (pfn_s & ~(P2M_MID_PER_PAGE * P2M_PER_PAGE - 1));
|
||||
pfn < ALIGN(pfn_e, (P2M_MID_PER_PAGE * P2M_PER_PAGE));
|
||||
pfn += P2M_MID_PER_PAGE * P2M_PER_PAGE)
|
||||
{
|
||||
unsigned topidx = p2m_top_index(pfn);
|
||||
if (p2m_top[topidx] == p2m_mid_missing) {
|
||||
unsigned long **mid = extend_brk(PAGE_SIZE, PAGE_SIZE);
|
||||
|
||||
p2m_mid_init(mid);
|
||||
|
||||
p2m_top[topidx] = mid;
|
||||
}
|
||||
}
|
||||
|
||||
__early_alloc_p2m(pfn_s);
|
||||
__early_alloc_p2m(pfn_e);
|
||||
|
||||
for (pfn = pfn_s; pfn < pfn_e; pfn++)
|
||||
if (!__set_phys_to_machine(pfn, IDENTITY_FRAME(pfn)))
|
||||
break;
|
||||
|
||||
if (!WARN((pfn - pfn_s) != (pfn_e - pfn_s),
|
||||
"Identity mapping failed. We are %ld short of 1-1 mappings!\n",
|
||||
(pfn_e - pfn_s) - (pfn - pfn_s)))
|
||||
printk(KERN_DEBUG "1-1 mapping on %lx->%lx\n", pfn_s, pfn);
|
||||
|
||||
return pfn - pfn_s;
|
||||
}
|
||||
|
||||
/* Try to install p2m mapping; fail if intermediate bits missing */
|
||||
bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn)
|
||||
{
|
||||
unsigned topidx, mididx, idx;
|
||||
|
||||
if (unlikely(xen_feature(XENFEAT_auto_translated_physmap))) {
|
||||
BUG_ON(pfn != mfn && mfn != INVALID_P2M_ENTRY);
|
||||
return true;
|
||||
}
|
||||
if (unlikely(pfn >= MAX_P2M_PFN)) {
|
||||
BUG_ON(mfn != INVALID_P2M_ENTRY);
|
||||
return true;
|
||||
@ -368,6 +591,21 @@ bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn)
|
||||
mididx = p2m_mid_index(pfn);
|
||||
idx = p2m_index(pfn);
|
||||
|
||||
/* For sparse holes were the p2m leaf has real PFN along with
|
||||
* PCI holes, stick in the PFN as the MFN value.
|
||||
*/
|
||||
if (mfn != INVALID_P2M_ENTRY && (mfn & IDENTITY_FRAME_BIT)) {
|
||||
if (p2m_top[topidx][mididx] == p2m_identity)
|
||||
return true;
|
||||
|
||||
/* Swap over from MISSING to IDENTITY if needed. */
|
||||
if (p2m_top[topidx][mididx] == p2m_missing) {
|
||||
WARN_ON(cmpxchg(&p2m_top[topidx][mididx], p2m_missing,
|
||||
p2m_identity) != p2m_missing);
|
||||
return true;
|
||||
}
|
||||
}
|
||||
|
||||
if (p2m_top[topidx][mididx] == p2m_missing)
|
||||
return mfn == INVALID_P2M_ENTRY;
|
||||
|
||||
@ -378,11 +616,6 @@ bool __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 true;
|
||||
}
|
||||
|
||||
if (unlikely(!__set_phys_to_machine(pfn, mfn))) {
|
||||
if (!alloc_p2m(pfn))
|
||||
return false;
|
||||
@ -520,3 +753,80 @@ 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
|
||||
|
||||
@ -52,6 +52,8 @@ phys_addr_t xen_extra_mem_start, xen_extra_mem_size;
|
||||
|
||||
static __init void xen_add_extra_mem(unsigned long pages)
|
||||
{
|
||||
unsigned long pfn;
|
||||
|
||||
u64 size = (u64)pages * PAGE_SIZE;
|
||||
u64 extra_start = xen_extra_mem_start + xen_extra_mem_size;
|
||||
|
||||
@ -66,6 +68,9 @@ static __init void xen_add_extra_mem(unsigned long pages)
|
||||
xen_extra_mem_size += size;
|
||||
|
||||
xen_max_p2m_pfn = PFN_DOWN(extra_start + size);
|
||||
|
||||
for (pfn = PFN_DOWN(extra_start); pfn <= xen_max_p2m_pfn; pfn++)
|
||||
__set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
|
||||
}
|
||||
|
||||
static unsigned long __init xen_release_chunk(phys_addr_t start_addr,
|
||||
@ -104,7 +109,7 @@ static unsigned long __init xen_release_chunk(phys_addr_t start_addr,
|
||||
WARN(ret != 1, "Failed to release memory %lx-%lx err=%d\n",
|
||||
start, end, ret);
|
||||
if (ret == 1) {
|
||||
set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
|
||||
__set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
|
||||
len++;
|
||||
}
|
||||
}
|
||||
@ -138,12 +143,55 @@ static unsigned long __init xen_return_unused_memory(unsigned long max_pfn,
|
||||
return released;
|
||||
}
|
||||
|
||||
static unsigned long __init xen_set_identity(const struct e820entry *list,
|
||||
ssize_t map_size)
|
||||
{
|
||||
phys_addr_t last = xen_initial_domain() ? 0 : ISA_END_ADDRESS;
|
||||
phys_addr_t start_pci = last;
|
||||
const struct e820entry *entry;
|
||||
unsigned long identity = 0;
|
||||
int i;
|
||||
|
||||
for (i = 0, entry = list; i < map_size; i++, entry++) {
|
||||
phys_addr_t start = entry->addr;
|
||||
phys_addr_t end = start + entry->size;
|
||||
|
||||
if (start < last)
|
||||
start = last;
|
||||
|
||||
if (end <= start)
|
||||
continue;
|
||||
|
||||
/* Skip over the 1MB region. */
|
||||
if (last > end)
|
||||
continue;
|
||||
|
||||
if (entry->type == E820_RAM) {
|
||||
if (start > start_pci)
|
||||
identity += set_phys_range_identity(
|
||||
PFN_UP(start_pci), PFN_DOWN(start));
|
||||
|
||||
/* Without saving 'last' we would gooble RAM too
|
||||
* at the end of the loop. */
|
||||
last = end;
|
||||
start_pci = end;
|
||||
continue;
|
||||
}
|
||||
start_pci = min(start, start_pci);
|
||||
last = end;
|
||||
}
|
||||
if (last > start_pci)
|
||||
identity += set_phys_range_identity(
|
||||
PFN_UP(start_pci), PFN_DOWN(last));
|
||||
return identity;
|
||||
}
|
||||
/**
|
||||
* machine_specific_memory_setup - Hook for machine specific memory setup.
|
||||
**/
|
||||
char * __init xen_memory_setup(void)
|
||||
{
|
||||
static struct e820entry map[E820MAX] __initdata;
|
||||
static struct e820entry map_raw[E820MAX] __initdata;
|
||||
|
||||
unsigned long max_pfn = xen_start_info->nr_pages;
|
||||
unsigned long long mem_end;
|
||||
@ -151,6 +199,7 @@ char * __init xen_memory_setup(void)
|
||||
struct xen_memory_map memmap;
|
||||
unsigned long extra_pages = 0;
|
||||
unsigned long extra_limit;
|
||||
unsigned long identity_pages = 0;
|
||||
int i;
|
||||
int op;
|
||||
|
||||
@ -176,6 +225,7 @@ char * __init xen_memory_setup(void)
|
||||
}
|
||||
BUG_ON(rc);
|
||||
|
||||
memcpy(map_raw, map, sizeof(map));
|
||||
e820.nr_map = 0;
|
||||
xen_extra_mem_start = mem_end;
|
||||
for (i = 0; i < memmap.nr_entries; i++) {
|
||||
@ -194,6 +244,15 @@ char * __init xen_memory_setup(void)
|
||||
end -= delta;
|
||||
|
||||
extra_pages += PFN_DOWN(delta);
|
||||
/*
|
||||
* Set RAM below 4GB that is not for us to be unusable.
|
||||
* This prevents "System RAM" address space from being
|
||||
* used as potential resource for I/O address (happens
|
||||
* when 'allocate_resource' is called).
|
||||
*/
|
||||
if (delta &&
|
||||
(xen_initial_domain() && end < 0x100000000ULL))
|
||||
e820_add_region(end, delta, E820_UNUSABLE);
|
||||
}
|
||||
|
||||
if (map[i].size > 0 && end > xen_extra_mem_start)
|
||||
@ -251,6 +310,13 @@ char * __init xen_memory_setup(void)
|
||||
|
||||
xen_add_extra_mem(extra_pages);
|
||||
|
||||
/*
|
||||
* Set P2M for all non-RAM pages and E820 gaps to be identity
|
||||
* type PFNs. We supply it with the non-sanitized version
|
||||
* of the E820.
|
||||
*/
|
||||
identity_pages = xen_set_identity(map_raw, memmap.nr_entries);
|
||||
printk(KERN_INFO "Set %ld page(s) to 1-1 mapping.\n", identity_pages);
|
||||
return "Xen";
|
||||
}
|
||||
|
||||
|
||||
@ -296,7 +296,7 @@ static int decrease_reservation(unsigned long nr_pages)
|
||||
/* No more mappings: invalidate P2M and add to balloon. */
|
||||
for (i = 0; i < nr_pages; i++) {
|
||||
pfn = mfn_to_pfn(frame_list[i]);
|
||||
set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
|
||||
__set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
|
||||
balloon_append(pfn_to_page(pfn));
|
||||
}
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user