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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] xen.git branch reorg / success with 2.6.30-rc3 pv_ops dom0
On Fri, 2009-06-05 at 14:19 -0400, Pasi KÃrkkÃinen wrote: > On Fri, Jun 05, 2009 at 05:12:33PM +0100, Ian Campbell wrote: > > On Fri, 2009-06-05 at 12:05 -0400, Ian Campbell wrote: > > > > > > I had some patches to unify the 32 and 64 bit versions of dump > page > > > table at one point, since the 64 bit version does the right thing. > > > I'll see if I can find or reproduce them. > > > > Couldn't find them but please try this: > > > > I had some problems applying the patch until I figured out it was > supposed > to be applied to a clean tree.. hopefully "git checkout file" restores > (or > resets) the file to it's original form and removes any local changes. Should work I guess, I usually use "git reset --hard" to undo any local mods. > > Here goes again: > http://pasik.reaktio.net/xen/pv_ops-dom0-debug/pv_ops-dom0-log-04-with-highpte-no-swap-with-debug2.txt > > > L4 at e1822000 is pinned contains L2 at e1977228 which points at an L1 > which is unpinned low mem address 0x8bf8000 OK so I think that is interesting. A pinned L4 referencing an unpinned L1 isn't supposed to happen, I don't think (Jeremy?). The patch at the end (applies to a clean tree again) walks the lowmem region of every L4 to ensure that every L1 page is pinned just before pinning the L4. I hope this will catch the L1 in the act. > PGD 8ef001 PUD 8ef001 PMD 1268067 PTE 207061 This just tells us that the PT which maps the PTE we were trying to write is mapped R/O, which is not as interesting as I thought it would be. > Fixmap KM_PTE0 @ 0xf57f0000 > PGD 8ef001 PUD 8ef001 PMD 207067 PTE 0 > Fixmap KM_PTE1 @ 0xf57ee000 > PGD 8ef001 PUD 8ef001 PMD 207067 PTE 0 So these guys are not at fault, although we are in the middle of filling in KM_PTE0, I think. I've just had another go reproing this with a xen-3.3-testing.hg hypervisor (both 32 and 64 bit) with a 32 bit kernel and dom0_mem=1024M. No luck... Ian. diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index f9b252c..538590a 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -285,46 +285,12 @@ check_v8086_mode(struct pt_regs *regs, unsigned long address, tsk->thread.screen_bitmap |= 1 << bit; } -static void dump_pagetable(unsigned long address) -{ - __typeof__(pte_val(__pte(0))) page; - - page = read_cr3(); - page = ((__typeof__(page) *) __va(page))[address >> PGDIR_SHIFT]; - #ifdef CONFIG_X86_PAE - printk("*pdpt = %016Lx ", page); - if ((page >> PAGE_SHIFT) < max_low_pfn - && page & _PAGE_PRESENT) { - page &= PAGE_MASK; - page = ((__typeof__(page) *) __va(page))[(address >> PMD_SHIFT) - & (PTRS_PER_PMD - 1)]; - printk(KERN_CONT "*pde = %016Lx ", page); - page &= ~_PAGE_NX; - } +#define FMTPTE "ll" #else - printk("*pde = %08lx ", page); +#define FMTPTE "l" #endif - /* - * We must not directly access the pte in the highpte - * case if the page table is located in highmem. - * And let's rather not kmap-atomic the pte, just in case - * it's allocated already: - */ - if ((page >> PAGE_SHIFT) < max_low_pfn - && (page & _PAGE_PRESENT) - && !(page & _PAGE_PSE)) { - - page &= PAGE_MASK; - page = ((__typeof__(page) *) __va(page))[(address >> PAGE_SHIFT) - & (PTRS_PER_PTE - 1)]; - printk("*pte = %0*Lx ", sizeof(page)*2, (u64)page); - } - - printk("\n"); -} - #else /* CONFIG_X86_64: */ void vmalloc_sync_all(void) @@ -440,6 +406,10 @@ check_v8086_mode(struct pt_regs *regs, unsigned long address, { } +#define FMTPTE "ll" + +#endif /* CONFIG_X86_64 */ + static int bad_address(void *p) { unsigned long dummy; @@ -447,7 +417,7 @@ static int bad_address(void *p) return probe_kernel_address((unsigned long *)p, dummy); } -static void dump_pagetable(unsigned long address) +void dump_pagetable(unsigned long address) { pgd_t *pgd; pud_t *pud; @@ -462,7 +432,7 @@ static void dump_pagetable(unsigned long address) if (bad_address(pgd)) goto bad; - printk("PGD %lx ", pgd_val(*pgd)); + printk("PGD %"FMTPTE"x ", pgd_val(*pgd)); if (!pgd_present(*pgd)) goto out; @@ -471,7 +441,7 @@ static void dump_pagetable(unsigned long address) if (bad_address(pud)) goto bad; - printk("PUD %lx ", pud_val(*pud)); + printk("PUD %"FMTPTE"x ", pud_val(*pud)); if (!pud_present(*pud) || pud_large(*pud)) goto out; @@ -479,7 +449,7 @@ static void dump_pagetable(unsigned long address) if (bad_address(pmd)) goto bad; - printk("PMD %lx ", pmd_val(*pmd)); + printk("PMD %"FMTPTE"x ", pmd_val(*pmd)); if (!pmd_present(*pmd) || pmd_large(*pmd)) goto out; @@ -487,7 +457,7 @@ static void dump_pagetable(unsigned long address) if (bad_address(pte)) goto bad; - printk("PTE %lx", pte_val(*pte)); + printk("PTE %"FMTPTE"x", pte_val(*pte)); out: printk("\n"); return; @@ -495,8 +465,6 @@ bad: printk("BAD\n"); } -#endif /* CONFIG_X86_64 */ - /* * Workaround for K8 erratum #93 & buggy BIOS. * @@ -598,6 +566,10 @@ show_fault_oops(struct pt_regs *regs, unsigned long error_code, printk_address(regs->ip, 1); dump_pagetable(address); + printk(KERN_CRIT "Fixmap KM_PTE0 @ %#lx\n", fix_to_virt(KM_PTE0)); + dump_pagetable(fix_to_virt(KM_PTE0)); + printk(KERN_CRIT "Fixmap KM_PTE1 @ %#lx\n", fix_to_virt(KM_PTE1)); + dump_pagetable(fix_to_virt(KM_PTE1)); } static noinline void diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index 1729178..2c427d3 100644 --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -1015,13 +1015,34 @@ static int xen_pin_page(struct mm_struct *mm, struct page *page, return flush; } +static int xen_check_l1_pinned(pte_t *pte, unsigned long s, unsigned long e, struct mm_walk *walk) +{ + extern void dump_pagetable(unsigned long address); + struct page *pte_page = virt_to_page(pte); + + if (!PagePinned(pte_page)) { + printk(KERN_CRIT "PTE @ %p is an L1 page %p covering %#lx-%#lx which is not pinned\n", pte, pte_page, s, e); + dump_pagetable((unsigned long)pte); + BUG(); + } + + return 0; +} + /* This is called just after a mm has been created, but it has not been used yet. We need to make sure that its pagetable is all read-only, and can be pinned. */ static void __xen_pgd_pin(struct mm_struct *mm, pgd_t *pgd) { + struct mm_walk xen_pin_walk = { + .pte_entry = &xen_check_l1_pinned, + .mm = mm, + }; + vm_unmap_aliases(); + walk_page_range(0xc0000000, FIXADDR_TOP, &xen_pin_walk); + xen_mc_batch(); if (__xen_pgd_walk(mm, pgd, xen_pin_page, USER_LIMIT)) { diff --git a/init/main.c b/init/main.c index 33ce929..baf4300 100644 --- a/init/main.c +++ b/init/main.c @@ -74,6 +74,8 @@ #include <asm/sections.h> #include <asm/cacheflush.h> +#include <asm/xen/page.h> + #ifdef CONFIG_X86_LOCAL_APIC #include <asm/smp.h> #endif @@ -815,6 +817,54 @@ static noinline int init_post(void) system_state = SYSTEM_RUNNING; numa_default_policy(); + { + extern void dump_pagetable(unsigned long address); + struct page *pgd_page, *pte_page; + pgd_t *pgd; + pud_t *pud; + pmd_t *pmd; + phys_addr_t pte_phys; + unsigned long address = 0xc08ce011UL;//(unsigned long) __builtin_return_address(0); + + pgd = pgd_offset(&init_mm, address); + if (!pgd_present(*pgd)) + goto skip; + + pud = pud_offset(pgd, address); + if (!pud_present(*pud)) + goto skip; + + pmd = pmd_offset(pud, address); + if (!pmd_present(*pmd)) + goto skip; + + pgd_page = virt_to_page(init_mm.pgd); + pte_page = pmd_page(*pmd); + + pte_phys = page_to_phys(pte_page) + pte_index(address); + printk(KERN_CRIT "Test debug infrastructure on address %#lx:\n", address); + printk(KERN_CRIT "L4 at V:%p/P:%#llx/M:%#llx is %s and contains L2 at V:%p/P:%#llx/M:%#llx = %#llx " + "which points to an L1 P:%#llx/M:%#llx which is %s %s\n", + pgd, virt_to_phys(pgd), virt_to_machine(pgd).maddr, + PagePinned(pgd_page) ? "pinned" : "unpinned", + pmd, virt_to_phys(pmd), virt_to_machine(pmd).maddr, + pmd_val(*pmd), + pte_phys, phys_to_machine(XPADDR(pte_phys)).maddr, + PagePinned(pte_page) ? "pinned" : "unpinned", + PageHighMem(pte_page) ? "highmem" : "lowmem"); + printk(KERN_CRIT "faulting address %#lx\n", address); + dump_pagetable(address); + if (!PageHighMem(pte_page)) { + printk(KERN_CRIT "lowmem mapping of L1 @ P:%#llx is at V:%p\n", pte_phys, phys_to_virt(page_to_phys(pte_page))); + dump_pagetable((unsigned long)phys_to_virt(page_to_phys(pte_page))); + } + printk(KERN_CRIT "Fixmap KM_PTE0 @ %#lx\n", fix_to_virt(KM_PTE0)); + dump_pagetable(fix_to_virt(KM_PTE0)); + printk(KERN_CRIT "Fixmap KM_PTE1 @ %#lx\n", fix_to_virt(KM_PTE1)); + dump_pagetable(fix_to_virt(KM_PTE1)); + } + skip: + if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0) printk(KERN_WARNING "Warning: unable to open an initial console.\n"); diff --git a/mm/rmap.c b/mm/rmap.c index 1652166..ced5650 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -52,6 +52,9 @@ #include <linux/migrate.h> #include <asm/tlbflush.h> +#include <asm/io.h> + +#include <asm/xen/page.h> #include "internal.h" @@ -267,6 +270,7 @@ unsigned long page_address_in_vma(struct page *page, struct vm_area_struct *vma) pte_t *page_check_address(struct page *page, struct mm_struct *mm, unsigned long address, spinlock_t **ptlp, int sync) { + struct page *pgd_page, *pte_page; pgd_t *pgd; pud_t *pud; pmd_t *pmd; @@ -285,6 +289,32 @@ pte_t *page_check_address(struct page *page, struct mm_struct *mm, if (!pmd_present(*pmd)) return NULL; + pgd_page = virt_to_page(mm->pgd); + pte_page = pmd_page(*pmd); + + if (PagePinned(pgd_page) != PagePinned(pte_page)) { + extern void dump_pagetable(unsigned long address); + phys_addr_t pte_phys = page_to_phys(pte_page) + pte_index(address); + printk(KERN_CRIT "L4 at V:%p/P:%#llx/M:%#llx is %s and contains L2 at V:%p/P:%#llx/M:%#llx = %#llx " + "which points to an L1 P:%#llx/M:%#llx which is %s %s\n", + pgd, virt_to_phys(pgd), virt_to_machine(pgd).maddr, + PagePinned(pgd_page) ? "pinned" : "unpinned", + pmd, virt_to_phys(pmd), virt_to_machine(pmd).maddr, + pmd_val(*pmd), + pte_phys, phys_to_machine(XPADDR(pte_phys)).maddr, + PagePinned(pte_page) ? "pinned" : "unpinned", + PageHighMem(pte_page) ? "highmem" : "lowmem"); + printk(KERN_CRIT "faulting address %#lx\n", address); + dump_pagetable(address); + if (!PageHighMem(pte_page)) { + printk(KERN_CRIT "lowmem mapping of L1 @ P:%#llx is at V:%p\n", pte_phys, phys_to_virt(page_to_phys(pte_page))); + dump_pagetable((unsigned long)phys_to_virt(page_to_phys(pte_page))); + } + printk(KERN_CRIT "Fixmap KM_PTE0 @ %#lx\n", fix_to_virt(KM_PTE0)); + dump_pagetable(fix_to_virt(KM_PTE0)); + printk(KERN_CRIT "Fixmap KM_PTE1 @ %#lx\n", fix_to_virt(KM_PTE1)); + dump_pagetable(fix_to_virt(KM_PTE1)); + } pte = pte_offset_map(pmd, address); /* Make a quick check before getting the lock */ if (!sync && !pte_present(*pte)) { _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel
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