mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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xen: move p2m handling to separate file
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This commit is contained in:
Jeremy Fitzhardinge
Konrad Rzeszutek Wilk
parent
8d3eaea246
commit
b5eafe924b
@ -12,7 +12,8 @@ CFLAGS_mmu.o := $(nostackp)
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obj-y := enlighten.o setup.o multicalls.o mmu.o irq.o \
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time.o xen-asm.o xen-asm_$(BITS).o \
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grant-table.o suspend.o platform-pci-unplug.o
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grant-table.o suspend.o platform-pci-unplug.o \
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p2m.o
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obj-$(CONFIG_SMP) += smp.o
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obj-$(CONFIG_PARAVIRT_SPINLOCKS)+= spinlock.o
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@ -173,371 +173,6 @@ DEFINE_PER_CPU(unsigned long, xen_current_cr3); /* actual vcpu cr3 */
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*/
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#define USER_LIMIT ((STACK_TOP_MAX + PGDIR_SIZE - 1) & PGDIR_MASK)
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/*
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* Xen leaves the responsibility for maintaining p2m mappings to the
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* guests themselves, but it must also access and update the p2m array
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* during suspend/resume when all the pages are reallocated.
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*
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* The p2m table is logically a flat array, but we implement it as a
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* three-level tree to allow the address space to be sparse.
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*
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* Xen
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* |
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* p2m_top p2m_top_mfn
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* / \ / \
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* p2m_mid p2m_mid p2m_mid_mfn p2m_mid_mfn
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* / \ / \ / /
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* p2m p2m p2m p2m p2m p2m p2m ...
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*
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* The p2m_mid_mfn pages are mapped by p2m_top_mfn_p.
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*
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* The p2m_top and p2m_top_mfn levels are limited to 1 page, so the
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* maximum representable pseudo-physical address space is:
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* P2M_TOP_PER_PAGE * P2M_MID_PER_PAGE * P2M_PER_PAGE pages
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*
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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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unsigned long xen_max_p2m_pfn __read_mostly;
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#define P2M_PER_PAGE (PAGE_SIZE / sizeof(unsigned long))
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#define P2M_MID_PER_PAGE (PAGE_SIZE / sizeof(unsigned long *))
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#define P2M_TOP_PER_PAGE (PAGE_SIZE / sizeof(unsigned long **))
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#define MAX_P2M_PFN (P2M_TOP_PER_PAGE * P2M_MID_PER_PAGE * P2M_PER_PAGE)
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/* Placeholders for holes in the address space */
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static RESERVE_BRK_ARRAY(unsigned long, p2m_missing, P2M_PER_PAGE);
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static RESERVE_BRK_ARRAY(unsigned long *, p2m_mid_missing, P2M_MID_PER_PAGE);
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static RESERVE_BRK_ARRAY(unsigned long, p2m_mid_missing_mfn, P2M_MID_PER_PAGE);
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static RESERVE_BRK_ARRAY(unsigned long **, p2m_top, P2M_TOP_PER_PAGE);
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static RESERVE_BRK_ARRAY(unsigned long, p2m_top_mfn, P2M_TOP_PER_PAGE);
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static RESERVE_BRK_ARRAY(unsigned long *, p2m_top_mfn_p, P2M_TOP_PER_PAGE);
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RESERVE_BRK(p2m_mid, PAGE_SIZE * (MAX_DOMAIN_PAGES / (P2M_PER_PAGE * P2M_MID_PER_PAGE)));
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RESERVE_BRK(p2m_mid_mfn, PAGE_SIZE * (MAX_DOMAIN_PAGES / (P2M_PER_PAGE * P2M_MID_PER_PAGE)));
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static inline unsigned p2m_top_index(unsigned long pfn)
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{
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BUG_ON(pfn >= MAX_P2M_PFN);
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return pfn / (P2M_MID_PER_PAGE * P2M_PER_PAGE);
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}
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static inline unsigned p2m_mid_index(unsigned long pfn)
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{
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return (pfn / P2M_PER_PAGE) % P2M_MID_PER_PAGE;
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}
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static inline unsigned p2m_index(unsigned long pfn)
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{
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return pfn % P2M_PER_PAGE;
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}
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static void p2m_top_init(unsigned long ***top)
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{
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unsigned i;
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for (i = 0; i < P2M_TOP_PER_PAGE; i++)
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top[i] = p2m_mid_missing;
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}
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static void p2m_top_mfn_init(unsigned long *top)
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{
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unsigned i;
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for (i = 0; i < P2M_TOP_PER_PAGE; i++)
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top[i] = virt_to_mfn(p2m_mid_missing_mfn);
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}
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static void p2m_top_mfn_p_init(unsigned long **top)
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{
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unsigned i;
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for (i = 0; i < P2M_TOP_PER_PAGE; i++)
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top[i] = p2m_mid_missing_mfn;
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}
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static void p2m_mid_init(unsigned long **mid)
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{
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unsigned i;
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for (i = 0; i < P2M_MID_PER_PAGE; i++)
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mid[i] = p2m_missing;
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}
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static void p2m_mid_mfn_init(unsigned long *mid)
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{
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unsigned i;
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for (i = 0; i < P2M_MID_PER_PAGE; i++)
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mid[i] = virt_to_mfn(p2m_missing);
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}
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static void p2m_init(unsigned long *p2m)
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{
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unsigned i;
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for (i = 0; i < P2M_MID_PER_PAGE; i++)
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p2m[i] = INVALID_P2M_ENTRY;
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}
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/*
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* Build the parallel p2m_top_mfn and p2m_mid_mfn structures
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*
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* This is called both at boot time, and after resuming from suspend:
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* - At boot time we're called very early, and must use extend_brk()
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* to allocate memory.
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*
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* - After resume we're called from within stop_machine, but the mfn
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* tree should alreay be completely allocated.
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*/
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void xen_build_mfn_list_list(void)
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{
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unsigned long pfn;
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/* Pre-initialize p2m_top_mfn to be completely missing */
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if (p2m_top_mfn == NULL) {
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p2m_mid_missing_mfn = extend_brk(PAGE_SIZE, PAGE_SIZE);
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p2m_mid_mfn_init(p2m_mid_missing_mfn);
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p2m_top_mfn_p = extend_brk(PAGE_SIZE, PAGE_SIZE);
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p2m_top_mfn_p_init(p2m_top_mfn_p);
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p2m_top_mfn = extend_brk(PAGE_SIZE, PAGE_SIZE);
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p2m_top_mfn_init(p2m_top_mfn);
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} else {
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/* Reinitialise, mfn's all change after migration */
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p2m_mid_mfn_init(p2m_mid_missing_mfn);
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}
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for (pfn = 0; pfn < xen_max_p2m_pfn; pfn += P2M_PER_PAGE) {
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unsigned topidx = p2m_top_index(pfn);
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unsigned mididx = p2m_mid_index(pfn);
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unsigned long **mid;
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unsigned long *mid_mfn_p;
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mid = p2m_top[topidx];
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mid_mfn_p = p2m_top_mfn_p[topidx];
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/* Don't bother allocating any mfn mid levels if
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* they're just missing, just update the stored mfn,
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* since all could have changed over a migrate.
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*/
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if (mid == p2m_mid_missing) {
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BUG_ON(mididx);
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BUG_ON(mid_mfn_p != p2m_mid_missing_mfn);
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p2m_top_mfn[topidx] = virt_to_mfn(p2m_mid_missing_mfn);
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pfn += (P2M_MID_PER_PAGE - 1) * P2M_PER_PAGE;
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continue;
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}
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if (mid_mfn_p == p2m_mid_missing_mfn) {
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/*
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* XXX boot-time only! We should never find
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* missing parts of the mfn tree after
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* runtime. extend_brk() will BUG if we call
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* it too late.
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*/
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mid_mfn_p = extend_brk(PAGE_SIZE, PAGE_SIZE);
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p2m_mid_mfn_init(mid_mfn_p);
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p2m_top_mfn_p[topidx] = mid_mfn_p;
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}
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p2m_top_mfn[topidx] = virt_to_mfn(mid_mfn_p);
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mid_mfn_p[mididx] = virt_to_mfn(mid[mididx]);
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}
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}
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void xen_setup_mfn_list_list(void)
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{
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BUG_ON(HYPERVISOR_shared_info == &xen_dummy_shared_info);
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HYPERVISOR_shared_info->arch.pfn_to_mfn_frame_list_list =
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virt_to_mfn(p2m_top_mfn);
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HYPERVISOR_shared_info->arch.max_pfn = xen_max_p2m_pfn;
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}
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/* Set up p2m_top to point to the domain-builder provided p2m pages */
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void __init xen_build_dynamic_phys_to_machine(void)
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{
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unsigned long *mfn_list = (unsigned long *)xen_start_info->mfn_list;
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unsigned long max_pfn = min(MAX_DOMAIN_PAGES, xen_start_info->nr_pages);
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unsigned long pfn;
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xen_max_p2m_pfn = max_pfn;
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p2m_missing = extend_brk(PAGE_SIZE, PAGE_SIZE);
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p2m_init(p2m_missing);
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p2m_mid_missing = extend_brk(PAGE_SIZE, PAGE_SIZE);
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p2m_mid_init(p2m_mid_missing);
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p2m_top = extend_brk(PAGE_SIZE, PAGE_SIZE);
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p2m_top_init(p2m_top);
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/*
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* The domain builder gives us a pre-constructed p2m array in
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* mfn_list for all the pages initially given to us, so we just
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* need to graft that into our tree structure.
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*/
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for (pfn = 0; pfn < max_pfn; pfn += P2M_PER_PAGE) {
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unsigned topidx = p2m_top_index(pfn);
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unsigned mididx = p2m_mid_index(pfn);
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if (p2m_top[topidx] == p2m_mid_missing) {
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unsigned long **mid = extend_brk(PAGE_SIZE, PAGE_SIZE);
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p2m_mid_init(mid);
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p2m_top[topidx] = mid;
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}
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p2m_top[topidx][mididx] = &mfn_list[pfn];
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}
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}
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unsigned long get_phys_to_machine(unsigned long pfn)
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{
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unsigned topidx, mididx, idx;
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if (unlikely(pfn >= MAX_P2M_PFN))
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return INVALID_P2M_ENTRY;
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topidx = p2m_top_index(pfn);
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mididx = p2m_mid_index(pfn);
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idx = p2m_index(pfn);
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return p2m_top[topidx][mididx][idx];
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}
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EXPORT_SYMBOL_GPL(get_phys_to_machine);
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static void *alloc_p2m_page(void)
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{
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return (void *)__get_free_page(GFP_KERNEL | __GFP_REPEAT);
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}
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static void free_p2m_page(void *p)
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{
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free_page((unsigned long)p);
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}
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/*
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* Fully allocate the p2m structure for a given pfn. We need to check
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* that both the top and mid levels are allocated, and make sure the
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* parallel mfn tree is kept in sync. We may race with other cpus, so
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* the new pages are installed with cmpxchg; if we lose the race then
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* simply free the page we allocated and use the one that's there.
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*/
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static bool alloc_p2m(unsigned long pfn)
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{
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unsigned topidx, mididx;
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unsigned long ***top_p, **mid;
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unsigned long *top_mfn_p, *mid_mfn;
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topidx = p2m_top_index(pfn);
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mididx = p2m_mid_index(pfn);
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top_p = &p2m_top[topidx];
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mid = *top_p;
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if (mid == p2m_mid_missing) {
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/* Mid level is missing, allocate a new one */
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mid = alloc_p2m_page();
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if (!mid)
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return false;
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p2m_mid_init(mid);
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if (cmpxchg(top_p, p2m_mid_missing, mid) != p2m_mid_missing)
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free_p2m_page(mid);
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}
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top_mfn_p = &p2m_top_mfn[topidx];
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mid_mfn = p2m_top_mfn_p[topidx];
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BUG_ON(virt_to_mfn(mid_mfn) != *top_mfn_p);
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if (mid_mfn == p2m_mid_missing_mfn) {
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/* Separately check the mid mfn level */
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unsigned long missing_mfn;
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unsigned long mid_mfn_mfn;
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mid_mfn = alloc_p2m_page();
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if (!mid_mfn)
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return false;
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p2m_mid_mfn_init(mid_mfn);
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missing_mfn = virt_to_mfn(p2m_mid_missing_mfn);
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mid_mfn_mfn = virt_to_mfn(mid_mfn);
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if (cmpxchg(top_mfn_p, missing_mfn, mid_mfn_mfn) != missing_mfn)
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free_p2m_page(mid_mfn);
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else
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p2m_top_mfn_p[topidx] = mid_mfn;
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}
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if (p2m_top[topidx][mididx] == p2m_missing) {
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/* p2m leaf page is missing */
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unsigned long *p2m;
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p2m = alloc_p2m_page();
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if (!p2m)
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return false;
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p2m_init(p2m);
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if (cmpxchg(&mid[mididx], p2m_missing, p2m) != p2m_missing)
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free_p2m_page(p2m);
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else
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mid_mfn[mididx] = virt_to_mfn(p2m);
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}
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return true;
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}
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/* Try to install p2m mapping; fail if intermediate bits missing */
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bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn)
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{
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unsigned topidx, mididx, idx;
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if (unlikely(pfn >= MAX_P2M_PFN)) {
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BUG_ON(mfn != INVALID_P2M_ENTRY);
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return true;
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}
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topidx = p2m_top_index(pfn);
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mididx = p2m_mid_index(pfn);
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idx = p2m_index(pfn);
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if (p2m_top[topidx][mididx] == p2m_missing)
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return mfn == INVALID_P2M_ENTRY;
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p2m_top[topidx][mididx][idx] = mfn;
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return true;
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}
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bool set_phys_to_machine(unsigned long pfn, unsigned long mfn)
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{
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if (unlikely(xen_feature(XENFEAT_auto_translated_physmap))) {
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BUG_ON(pfn != mfn && mfn != INVALID_P2M_ENTRY);
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return true;
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}
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if (unlikely(!__set_phys_to_machine(pfn, mfn))) {
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if (!alloc_p2m(pfn))
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return false;
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if (!__set_phys_to_machine(pfn, mfn))
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return false;
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}
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return true;
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}
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unsigned long arbitrary_virt_to_mfn(void *vaddr)
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{
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xmaddr_t maddr = arbitrary_virt_to_machine(vaddr);
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376
arch/x86/xen/p2m.c
Normal file
376
arch/x86/xen/p2m.c
Normal file
@ -0,0 +1,376 @@
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/*
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* Xen leaves the responsibility for maintaining p2m mappings to the
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* guests themselves, but it must also access and update the p2m array
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* during suspend/resume when all the pages are reallocated.
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*
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* The p2m table is logically a flat array, but we implement it as a
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* three-level tree to allow the address space to be sparse.
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*
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* Xen
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* |
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* p2m_top p2m_top_mfn
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* / \ / \
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* p2m_mid p2m_mid p2m_mid_mfn p2m_mid_mfn
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* / \ / \ / /
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* p2m p2m p2m p2m p2m p2m p2m ...
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*
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* The p2m_mid_mfn pages are mapped by p2m_top_mfn_p.
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*
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* The p2m_top and p2m_top_mfn levels are limited to 1 page, so the
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* maximum representable pseudo-physical address space is:
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* P2M_TOP_PER_PAGE * P2M_MID_PER_PAGE * P2M_PER_PAGE pages
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*
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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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#include <linux/init.h>
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#include <linux/module.h>
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#include <asm/cache.h>
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#include <asm/setup.h>
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#include <asm/xen/page.h>
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#include <asm/xen/hypercall.h>
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#include <asm/xen/hypervisor.h>
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#include "xen-ops.h"
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unsigned long xen_max_p2m_pfn __read_mostly;
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#define P2M_PER_PAGE (PAGE_SIZE / sizeof(unsigned long))
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#define P2M_MID_PER_PAGE (PAGE_SIZE / sizeof(unsigned long *))
|
||||
#define P2M_TOP_PER_PAGE (PAGE_SIZE / sizeof(unsigned long **))
|
||||
|
||||
#define MAX_P2M_PFN (P2M_TOP_PER_PAGE * P2M_MID_PER_PAGE * P2M_PER_PAGE)
|
||||
|
||||
/* 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);
|
||||
|
||||
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);
|
||||
|
||||
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_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_PER_PAGE;
|
||||
}
|
||||
|
||||
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 long 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 = 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 (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]);
|
||||
}
|
||||
}
|
||||
|
||||
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);
|
||||
HYPERVISOR_shared_info->arch.max_pfn = xen_max_p2m_pfn;
|
||||
}
|
||||
|
||||
/* Set up p2m_top to point to the domain-builder provided p2m pages */
|
||||
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 long pfn;
|
||||
|
||||
xen_max_p2m_pfn = max_pfn;
|
||||
|
||||
p2m_missing = extend_brk(PAGE_SIZE, PAGE_SIZE);
|
||||
p2m_init(p2m_missing);
|
||||
|
||||
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);
|
||||
|
||||
if (p2m_top[topidx] == p2m_mid_missing) {
|
||||
unsigned long **mid = extend_brk(PAGE_SIZE, PAGE_SIZE);
|
||||
p2m_mid_init(mid);
|
||||
|
||||
p2m_top[topidx] = mid;
|
||||
}
|
||||
|
||||
p2m_top[topidx][mididx] = &mfn_list[pfn];
|
||||
}
|
||||
}
|
||||
|
||||
unsigned long get_phys_to_machine(unsigned long pfn)
|
||||
{
|
||||
unsigned topidx, mididx, idx;
|
||||
|
||||
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][mididx][idx];
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(get_phys_to_machine);
|
||||
|
||||
static void *alloc_p2m_page(void)
|
||||
{
|
||||
return (void *)__get_free_page(GFP_KERNEL | __GFP_REPEAT);
|
||||
}
|
||||
|
||||
static void free_p2m_page(void *p)
|
||||
{
|
||||
free_page((unsigned long)p);
|
||||
}
|
||||
|
||||
/*
|
||||
* 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;
|
||||
|
||||
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);
|
||||
}
|
||||
|
||||
top_mfn_p = &p2m_top_mfn[topidx];
|
||||
mid_mfn = p2m_top_mfn_p[topidx];
|
||||
|
||||
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);
|
||||
|
||||
if (cmpxchg(&mid[mididx], p2m_missing, p2m) != p2m_missing)
|
||||
free_p2m_page(p2m);
|
||||
else
|
||||
mid_mfn[mididx] = virt_to_mfn(p2m);
|
||||
}
|
||||
|
||||
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, mididx, idx;
|
||||
|
||||
if (unlikely(pfn >= MAX_P2M_PFN)) {
|
||||
BUG_ON(mfn != INVALID_P2M_ENTRY);
|
||||
return true;
|
||||
}
|
||||
|
||||
topidx = p2m_top_index(pfn);
|
||||
mididx = p2m_mid_index(pfn);
|
||||
idx = p2m_index(pfn);
|
||||
|
||||
if (p2m_top[topidx][mididx] == p2m_missing)
|
||||
return mfn == INVALID_P2M_ENTRY;
|
||||
|
||||
p2m_top[topidx][mididx][idx] = mfn;
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
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;
|
||||
|
||||
if (!__set_phys_to_machine(pfn, mfn))
|
||||
return false;
|
||||
}
|
||||
|
||||
return true;
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user