diff options
Diffstat (limited to 'drivers/lguest/page_tables.c')
| -rw-r--r-- | drivers/lguest/page_tables.c | 59 |
1 files changed, 30 insertions, 29 deletions
diff --git a/drivers/lguest/page_tables.c b/drivers/lguest/page_tables.c index e34c81636a8c..fb665611ccc2 100644 --- a/drivers/lguest/page_tables.c +++ b/drivers/lguest/page_tables.c @@ -94,10 +94,10 @@ static pte_t *spte_addr(struct lguest *lg, pgd_t spgd, unsigned long vaddr) /* These two functions just like the above two, except they access the Guest * page tables. Hence they return a Guest address. */ -static unsigned long gpgd_addr(struct lguest *lg, unsigned long vaddr) +static unsigned long gpgd_addr(struct lg_cpu *cpu, unsigned long vaddr) { unsigned int index = vaddr >> (PGDIR_SHIFT); - return lg->pgdirs[lg->pgdidx].gpgdir + index * sizeof(pgd_t); + return cpu->lg->pgdirs[cpu->cpu_pgd].gpgdir + index * sizeof(pgd_t); } static unsigned long gpte_addr(struct lguest *lg, @@ -200,22 +200,23 @@ static void check_gpgd(struct lguest *lg, pgd_t gpgd) * * If we fixed up the fault (ie. we mapped the address), this routine returns * true. Otherwise, it was a real fault and we need to tell the Guest. */ -int demand_page(struct lguest *lg, unsigned long vaddr, int errcode) +int demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode) { pgd_t gpgd; pgd_t *spgd; unsigned long gpte_ptr; pte_t gpte; pte_t *spte; + struct lguest *lg = cpu->lg; /* First step: get the top-level Guest page table entry. */ - gpgd = lgread(lg, gpgd_addr(lg, vaddr), pgd_t); + gpgd = lgread(lg, gpgd_addr(cpu, vaddr), pgd_t); /* Toplevel not present? We can't map it in. */ if (!(pgd_flags(gpgd) & _PAGE_PRESENT)) return 0; /* Now look at the matching shadow entry. */ - spgd = spgd_addr(lg, lg->pgdidx, vaddr); + spgd = spgd_addr(lg, cpu->cpu_pgd, vaddr); if (!(pgd_flags(*spgd) & _PAGE_PRESENT)) { /* No shadow entry: allocate a new shadow PTE page. */ unsigned long ptepage = get_zeroed_page(GFP_KERNEL); @@ -297,19 +298,19 @@ int demand_page(struct lguest *lg, unsigned long vaddr, int errcode) * * This is a quick version which answers the question: is this virtual address * mapped by the shadow page tables, and is it writable? */ -static int page_writable(struct lguest *lg, unsigned long vaddr) +static int page_writable(struct lg_cpu *cpu, unsigned long vaddr) { pgd_t *spgd; unsigned long flags; /* Look at the current top level entry: is it present? */ - spgd = spgd_addr(lg, lg->pgdidx, vaddr); + spgd = spgd_addr(cpu->lg, cpu->cpu_pgd, vaddr); if (!(pgd_flags(*spgd) & _PAGE_PRESENT)) return 0; /* Check the flags on the pte entry itself: it must be present and * writable. */ - flags = pte_flags(*(spte_addr(lg, *spgd, vaddr))); + flags = pte_flags(*(spte_addr(cpu->lg, *spgd, vaddr))); return (flags & (_PAGE_PRESENT|_PAGE_RW)) == (_PAGE_PRESENT|_PAGE_RW); } @@ -317,10 +318,10 @@ static int page_writable(struct lguest *lg, unsigned long vaddr) /* So, when pin_stack_pages() asks us to pin a page, we check if it's already * in the page tables, and if not, we call demand_page() with error code 2 * (meaning "write"). */ -void pin_page(struct lguest *lg, unsigned long vaddr) +void pin_page(struct lg_cpu *cpu, unsigned long vaddr) { - if (!page_writable(lg, vaddr) && !demand_page(lg, vaddr, 2)) - kill_guest(lg, "bad stack page %#lx", vaddr); + if (!page_writable(cpu, vaddr) && !demand_page(cpu, vaddr, 2)) + kill_guest(cpu->lg, "bad stack page %#lx", vaddr); } /*H:450 If we chase down the release_pgd() code, it looks like this: */ @@ -358,28 +359,28 @@ static void flush_user_mappings(struct lguest *lg, int idx) * * The Guest has a hypercall to throw away the page tables: it's used when a * large number of mappings have been changed. */ -void guest_pagetable_flush_user(struct lguest *lg) +void guest_pagetable_flush_user(struct lg_cpu *cpu) { /* Drop the userspace part of the current page table. */ - flush_user_mappings(lg, lg->pgdidx); + flush_user_mappings(cpu->lg, cpu->cpu_pgd); } /*:*/ /* We walk down the guest page tables to get a guest-physical address */ -unsigned long guest_pa(struct lguest *lg, unsigned long vaddr) +unsigned long guest_pa(struct lg_cpu *cpu, unsigned long vaddr) { pgd_t gpgd; pte_t gpte; /* First step: get the top-level Guest page table entry. */ - gpgd = lgread(lg, gpgd_addr(lg, vaddr), pgd_t); + gpgd = lgread(cpu->lg, gpgd_addr(cpu, vaddr), pgd_t); /* Toplevel not present? We can't map it in. */ if (!(pgd_flags(gpgd) & _PAGE_PRESENT)) - kill_guest(lg, "Bad address %#lx", vaddr); + kill_guest(cpu->lg, "Bad address %#lx", vaddr); - gpte = lgread(lg, gpte_addr(lg, gpgd, vaddr), pte_t); + gpte = lgread(cpu->lg, gpte_addr(cpu->lg, gpgd, vaddr), pte_t); if (!(pte_flags(gpte) & _PAGE_PRESENT)) - kill_guest(lg, "Bad address %#lx", vaddr); + kill_guest(cpu->lg, "Bad address %#lx", vaddr); return pte_pfn(gpte) * PAGE_SIZE | (vaddr & ~PAGE_MASK); } @@ -399,11 +400,12 @@ static unsigned int find_pgdir(struct lguest *lg, unsigned long pgtable) /*H:435 And this is us, creating the new page directory. If we really do * allocate a new one (and so the kernel parts are not there), we set * blank_pgdir. */ -static unsigned int new_pgdir(struct lguest *lg, +static unsigned int new_pgdir(struct lg_cpu *cpu, unsigned long gpgdir, int *blank_pgdir) { unsigned int next; + struct lguest *lg = cpu->lg; /* We pick one entry at random to throw out. Choosing the Least * Recently Used might be better, but this is easy. */ @@ -413,7 +415,7 @@ static unsigned int new_pgdir(struct lguest *lg, lg->pgdirs[next].pgdir = (pgd_t *)get_zeroed_page(GFP_KERNEL); /* If the allocation fails, just keep using the one we have */ if (!lg->pgdirs[next].pgdir) - next = lg->pgdidx; + next = cpu->cpu_pgd; else /* This is a blank page, so there are no kernel * mappings: caller must map the stack! */ @@ -442,9 +444,9 @@ void guest_new_pagetable(struct lg_cpu *cpu, unsigned long pgtable) /* If not, we allocate or mug an existing one: if it's a fresh one, * repin gets set to 1. */ if (newpgdir == ARRAY_SIZE(lg->pgdirs)) - newpgdir = new_pgdir(lg, pgtable, &repin); + newpgdir = new_pgdir(cpu, pgtable, &repin); /* Change the current pgd index to the new one. */ - lg->pgdidx = newpgdir; + cpu->cpu_pgd = newpgdir; /* If it was completely blank, we map in the Guest kernel stack */ if (repin) pin_stack_pages(cpu); @@ -591,11 +593,11 @@ int init_guest_pagetable(struct lguest *lg, unsigned long pgtable) { /* We start on the first shadow page table, and give it a blank PGD * page. */ - lg->pgdidx = 0; - lg->pgdirs[lg->pgdidx].gpgdir = pgtable; - lg->pgdirs[lg->pgdidx].pgdir = (pgd_t*)get_zeroed_page(GFP_KERNEL); - if (!lg->pgdirs[lg->pgdidx].pgdir) + lg->pgdirs[0].gpgdir = pgtable; + lg->pgdirs[0].pgdir = (pgd_t *)get_zeroed_page(GFP_KERNEL); + if (!lg->pgdirs[0].pgdir) return -ENOMEM; + lg->cpus[0].cpu_pgd = 0; return 0; } @@ -607,7 +609,7 @@ void page_table_guest_data_init(struct lguest *lg) /* We tell the Guest that it can't use the top 4MB of virtual * addresses used by the Switcher. */ || put_user(4U*1024*1024, &lg->lguest_data->reserve_mem) - || put_user(lg->pgdirs[lg->pgdidx].gpgdir,&lg->lguest_data->pgdir)) + || put_user(lg->pgdirs[0].gpgdir, &lg->lguest_data->pgdir)) kill_guest(lg, "bad guest page %p", lg->lguest_data); /* In flush_user_mappings() we loop from 0 to @@ -637,7 +639,6 @@ void free_guest_pagetable(struct lguest *lg) * Guest is about to run on this CPU. */ void map_switcher_in_guest(struct lg_cpu *cpu, struct lguest_pages *pages) { - struct lguest *lg = cpu->lg; pte_t *switcher_pte_page = __get_cpu_var(switcher_pte_pages); pgd_t switcher_pgd; pte_t regs_pte; @@ -647,7 +648,7 @@ void map_switcher_in_guest(struct lg_cpu *cpu, struct lguest_pages *pages) * page for this CPU (with appropriate flags). */ switcher_pgd = __pgd(__pa(switcher_pte_page) | _PAGE_KERNEL); - lg->pgdirs[lg->pgdidx].pgdir[SWITCHER_PGD_INDEX] = switcher_pgd; + cpu->lg->pgdirs[cpu->cpu_pgd].pgdir[SWITCHER_PGD_INDEX] = switcher_pgd; /* We also change the Switcher PTE page. When we're running the Guest, * we want the Guest's "regs" page to appear where the first Switcher |