diff options
| -rw-r--r-- | arch/x86/include/asm/xen/page.h | 16 | ||||
| -rw-r--r-- | arch/x86/xen/Makefile | 3 | ||||
| -rw-r--r-- | arch/x86/xen/mmu.c | 365 | ||||
| -rw-r--r-- | arch/x86/xen/p2m.c | 510 | ||||
| -rw-r--r-- | drivers/xen/Kconfig | 9 | ||||
| -rw-r--r-- | drivers/xen/Makefile | 2 | ||||
| -rw-r--r-- | drivers/xen/gntdev.c | 665 | ||||
| -rw-r--r-- | drivers/xen/grant-table.c | 46 | ||||
| -rw-r--r-- | include/xen/gntdev.h | 119 | ||||
| -rw-r--r-- | include/xen/grant_table.h | 44 |
10 files changed, 1408 insertions, 371 deletions
diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h index 8760cc6..f25bdf2 100644 --- a/arch/x86/include/asm/xen/page.h +++ b/arch/x86/include/asm/xen/page.h @@ -42,6 +42,11 @@ extern unsigned int machine_to_phys_order; extern unsigned long get_phys_to_machine(unsigned long pfn); extern bool set_phys_to_machine(unsigned long pfn, unsigned long mfn); +extern int m2p_add_override(unsigned long mfn, struct page *page); +extern int m2p_remove_override(struct page *page); +extern struct page *m2p_find_override(unsigned long mfn); +extern unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn); + static inline unsigned long pfn_to_mfn(unsigned long pfn) { unsigned long mfn; @@ -72,9 +77,6 @@ static inline unsigned long mfn_to_pfn(unsigned long mfn) if (xen_feature(XENFEAT_auto_translated_physmap)) return mfn; - if (unlikely((mfn >> machine_to_phys_order) != 0)) - return ~0; - pfn = 0; /* * The array access can fail (e.g., device space beyond end of RAM). @@ -83,6 +85,14 @@ static inline unsigned long mfn_to_pfn(unsigned long mfn) */ __get_user(pfn, &machine_to_phys_mapping[mfn]); + /* + * If this appears to be a foreign mfn (because the pfn + * doesn't map back to the mfn), then check the local override + * table to see if there's a better pfn to use. + */ + if (get_phys_to_machine(pfn) != mfn) + pfn = m2p_find_override_pfn(mfn, pfn); + return pfn; } diff --git a/arch/x86/xen/Makefile b/arch/x86/xen/Makefile index 7793851..17c565d 100644 --- a/arch/x86/xen/Makefile +++ b/arch/x86/xen/Makefile @@ -12,7 +12,8 @@ CFLAGS_mmu.o := $(nostackp) obj-y := enlighten.o setup.o multicalls.o mmu.o irq.o \ time.o xen-asm.o xen-asm_$(BITS).o \ - grant-table.o suspend.o platform-pci-unplug.o + grant-table.o suspend.o platform-pci-unplug.o \ + p2m.o obj-$(CONFIG_SMP) += smp.o obj-$(CONFIG_PARAVIRT_SPINLOCKS)+= spinlock.o diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index 44924e5..7575e55 100644 --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -173,371 +173,6 @@ DEFINE_PER_CPU(unsigned long, xen_current_cr3); /* actual vcpu cr3 */ */ #define USER_LIMIT ((STACK_TOP_MAX + PGDIR_SIZE - 1) & PGDIR_MASK) -/* - * Xen leaves the responsibility for maintaining p2m mappings to the - * guests themselves, but it must also access and update the p2m array - * during suspend/resume when all the pages are reallocated. - * - * The p2m table is logically a flat array, but we implement it as a - * three-level tree to allow the address space to be sparse. - * - * Xen - * | - * p2m_top p2m_top_mfn - * / \ / \ - * p2m_mid p2m_mid p2m_mid_mfn p2m_mid_mfn - * / \ / \ / / - * p2m p2m p2m p2m p2m p2m p2m ... - * - * The p2m_mid_mfn pages are mapped by p2m_top_mfn_p. - * - * The p2m_top and p2m_top_mfn levels are limited to 1 page, so the - * maximum representable pseudo-physical address space is: - * P2M_TOP_PER_PAGE * P2M_MID_PER_PAGE * P2M_PER_PAGE pages - * - * P2M_PER_PAGE depends on the architecture, as a mfn is always - * unsigned long (8 bytes on 64-bit, 4 bytes on 32), leading to - * 512 and 1024 entries respectively. - */ - -unsigned long xen_max_p2m_pfn __read_mostly; - -#define P2M_PER_PAGE (PAGE_SIZE / sizeof(unsigned long)) -#define P2M_MID_PER_PAGE (PAGE_SIZE / sizeof(unsigned long *)) -#define P2M_TOP_PER_PAGE (PAGE_SIZE / sizeof(unsigned long **)) - -#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; -} - unsigned long arbitrary_virt_to_mfn(void *vaddr) { xmaddr_t maddr = arbitrary_virt_to_machine(vaddr); diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c new file mode 100644 index 0000000..8f2251d --- /dev/null +++ b/arch/x86/xen/p2m.c @@ -0,0 +1,510 @@ +/* + * Xen leaves the responsibility for maintaining p2m mappings to the + * guests themselves, but it must also access and update the p2m array + * during suspend/resume when all the pages are reallocated. + * + * The p2m table is logically a flat array, but we implement it as a + * three-level tree to allow the address space to be sparse. + * + * Xen + * | + * p2m_top p2m_top_mfn + * / \ / \ + * p2m_mid p2m_mid p2m_mid_mfn p2m_mid_mfn + * / \ / \ / / + * p2m p2m p2m p2m p2m p2m p2m ... + * + * The p2m_mid_mfn pages are mapped by p2m_top_mfn_p. + * + * The p2m_top and p2m_top_mfn levels are limited to 1 page, so the + * maximum representable pseudo-physical address space is: + * P2M_TOP_PER_PAGE * P2M_MID_PER_PAGE * P2M_PER_PAGE pages + * + * P2M_PER_PAGE depends on the architecture, as a mfn is always + * unsigned long (8 bytes on 64-bit, 4 bytes on 32), leading to + * 512 and 1024 entries respectively. + */ + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/list.h> +#include <linux/hash.h> +#include <linux/sched.h> + +#include <asm/cache.h> +#include <asm/setup.h> + +#include <asm/xen/page.h> +#include <asm/xen/hypercall.h> +#include <asm/xen/hypervisor.h> + +#include "xen-ops.h" + +static void __init m2p_override_init(void); + +unsigned long xen_max_p2m_pfn __read_mostly; + +#define P2M_PER_PAGE (PAGE_SIZE / sizeof(unsigned long)) +#define P2M_MID_PER_PAGE (PAGE_SIZE / sizeof(unsigned long *)) +#define P2M_TOP_PER_PAGE (PAGE_SIZE / sizeof(unsigned long **)) + +#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]; + } + + m2p_override_init(); +} + +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; +} + +#define M2P_OVERRIDE_HASH_SHIFT 10 +#define M2P_OVERRIDE_HASH (1 << M2P_OVERRIDE_HASH_SHIFT) + +static RESERVE_BRK_ARRAY(struct list_head, m2p_overrides, M2P_OVERRIDE_HASH); +static DEFINE_SPINLOCK(m2p_override_lock); + +static void __init m2p_override_init(void) +{ + unsigned i; + + m2p_overrides = extend_brk(sizeof(*m2p_overrides) * M2P_OVERRIDE_HASH, + sizeof(unsigned long)); + + for (i = 0; i < M2P_OVERRIDE_HASH; i++) + INIT_LIST_HEAD(&m2p_overrides[i]); +} + +static unsigned long mfn_hash(unsigned long mfn) +{ + return hash_long(mfn, M2P_OVERRIDE_HASH_SHIFT); +} + +/* Add an MFN override for a particular page */ +int m2p_add_override(unsigned long mfn, struct page *page) +{ + unsigned long flags; + unsigned long pfn; + unsigned long address; + unsigned level; + pte_t *ptep = NULL; + + pfn = page_to_pfn(page); + if (!PageHighMem(page)) { + address = (unsigned long)__va(pfn << PAGE_SHIFT); + ptep = lookup_address(address, &level); + + if (WARN(ptep == NULL || level != PG_LEVEL_4K, + "m2p_add_override: pfn %lx not mapped", pfn)) + return -EINVAL; + } + + page->private = mfn; + page->index = pfn_to_mfn(pfn); + + __set_phys_to_machine(pfn, FOREIGN_FRAME(mfn)); + if (!PageHighMem(page)) + /* Just zap old mapping for now */ + pte_clear(&init_mm, address, ptep); + + spin_lock_irqsave(&m2p_override_lock, flags); + list_add(&page->lru, &m2p_overrides[mfn_hash(mfn)]); + spin_unlock_irqrestore(&m2p_override_lock, flags); + + return 0; +} + +int m2p_remove_override(struct page *page) +{ + unsigned long flags; + unsigned long mfn; + unsigned long pfn; + unsigned long address; + unsigned level; + pte_t *ptep = NULL; + + pfn = page_to_pfn(page); + mfn = get_phys_to_machine(pfn); + if (mfn == INVALID_P2M_ENTRY || !(mfn & FOREIGN_FRAME_BIT)) + return -EINVAL; + + if (!PageHighMem(page)) { + address = (unsigned long)__va(pfn << PAGE_SHIFT); + ptep = lookup_address(address, &level); + + if (WARN(ptep == NULL || level != PG_LEVEL_4K, + "m2p_remove_override: pfn %lx not mapped", pfn)) + return -EINVAL; + } + + spin_lock_irqsave(&m2p_override_lock, flags); + list_del(&page->lru); + spin_unlock_irqrestore(&m2p_override_lock, flags); + __set_phys_to_machine(pfn, page->index); + + if (!PageHighMem(page)) + set_pte_at(&init_mm, address, ptep, + pfn_pte(pfn, PAGE_KERNEL)); + /* No tlb flush necessary because the caller already + * left the pte unmapped. */ + + return 0; +} + +struct page *m2p_find_override(unsigned long mfn) +{ + unsigned long flags; + struct list_head *bucket = &m2p_overrides[mfn_hash(mfn)]; + struct page *p, *ret; + + ret = NULL; + + spin_lock_irqsave(&m2p_override_lock, flags); + + list_for_each_entry(p, bucket, lru) { + if (p->private == mfn) { + ret = p; + break; + } + } + + spin_unlock_irqrestore(&m2p_override_lock, flags); + + return ret; +} + +unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn) +{ + struct page *p = m2p_find_override(mfn); + unsigned long ret = pfn; + + if (p) + ret = page_to_pfn(p); + + return ret; +} +EXPORT_SYMBOL_GPL(m2p_find_override_pfn); diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig index 464d893..07bec09 100644 --- a/drivers/xen/Kconfig +++ b/drivers/xen/Kconfig @@ -71,7 +71,14 @@ config XEN_SYS_HYPERVISOR but will have no xen contents. config XEN_XENBUS_FRONTEND - tristate + tristate + +config XEN_GNTDEV + tristate "userspace grant access device driver" + depends on XEN + select MMU_NOTIFIER + help + Allows userspace processes to use grants. config XEN_PLATFORM_PCI tristate "xen platform pci device driver" diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile index f81819b..5088cc2 100644 --- a/drivers/xen/Makefile +++ b/drivers/xen/Makefile @@ -9,6 +9,7 @@ obj-$(CONFIG_HOTPLUG_CPU) += cpu_hotplug.o obj-$(CONFIG_XEN_XENCOMM) += xencomm.o obj-$(CONFIG_XEN_BALLOON) += balloon.o obj-$(CONFIG_XEN_DEV_EVTCHN) += xen-evtchn.o +obj-$(CONFIG_XEN_GNTDEV) += xen-gntdev.o obj-$(CONFIG_XENFS) += xenfs/ obj-$(CONFIG_XEN_SYS_HYPERVISOR) += sys-hypervisor.o obj-$(CONFIG_XEN_PLATFORM_PCI) += xen-platform-pci.o @@ -16,5 +17,6 @@ obj-$(CONFIG_SWIOTLB_XEN) += swiotlb-xen.o obj-$(CONFIG_XEN_DOM0) += pci.o xen-evtchn-y := evtchn.o +xen-gntdev-y := gntdev.o xen-platform-pci-y := platform-pci.o diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c new file mode 100644 index 0000000..1e31cdc --- /dev/null +++ b/drivers/xen/gntdev.c @@ -0,0 +1,665 @@ +/****************************************************************************** + * gntdev.c + * + * Device for accessing (in user-space) pages that have been granted by other + * domains. + * + * Copyright (c) 2006-2007, D G Murray. + * (c) 2009 Gerd Hoffmann <kraxel@redhat.com> + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#undef DEBUG + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/miscdevice.h> +#include <linux/fs.h> +#include <linux/mm.h> +#include <linux/mman.h> +#include <linux/mmu_notifier.h> +#include <linux/types.h> +#include <linux/uaccess.h> +#include <linux/sched.h> +#include <linux/spinlock.h> +#include <linux/slab.h> + +#include <xen/xen.h> +#include <xen/grant_table.h> +#include <xen/gntdev.h> +#include <asm/xen/hypervisor.h> +#include <asm/xen/hypercall.h> +#include <asm/xen/page.h> + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Derek G. Murray <Derek.Murray@cl.cam.ac.uk>, " + "Gerd Hoffmann <kraxel@redhat.com>"); +MODULE_DESCRIPTION("User-space granted page access driver"); + +static int limit = 1024; +module_param(limit, int, 0644); +MODULE_PARM_DESC(limit, "Maximum number of grants that may be mapped at " + "once by a gntdev instance"); + +struct gntdev_priv { + struct list_head maps; + uint32_t used; + uint32_t limit; + /* lock protects maps from concurrent changes */ + spinlock_t lock; + struct mm_struct *mm; + struct mmu_notifier mn; +}; + +struct grant_map { + struct list_head next; + struct gntdev_priv *priv; + struct vm_area_struct *vma; + int index; + int count; + int flags; + int is_mapped; + struct ioctl_gntdev_grant_ref *grants; + struct gnttab_map_grant_ref *map_ops; + struct gnttab_unmap_grant_ref *unmap_ops; + struct page **pages; +}; + +/* ------------------------------------------------------------------ */ + +static void gntdev_print_maps(struct gntdev_priv *priv, + char *text, int text_index) +{ +#ifdef DEBUG + struct grant_map *map; + + pr_debug("maps list (priv %p, usage %d/%d)\n", + priv, priv->used, priv->limit); + + list_for_each_entry(map, &priv->maps, next) + pr_debug(" index %2d, count %2d %s\n", + map->index, map->count, + map->index == text_index && text ? text : ""); +#endif +} + +static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count) +{ + struct grant_map *add; + int i; + + add = kzalloc(sizeof(struct grant_map), GFP_KERNEL); + if (NULL == add) + return NULL; + + add->grants = kzalloc(sizeof(add->grants[0]) * count, GFP_KERNEL); + add->map_ops = kzalloc(sizeof(add->map_ops[0]) * count, GFP_KERNEL); + add->unmap_ops = kzalloc(sizeof(add->unmap_ops[0]) * count, GFP_KERNEL); + add->pages = kzalloc(sizeof(add->pages[0]) * count, GFP_KERNEL); + if (NULL == add->grants || + NULL == add->map_ops || + NULL == add->unmap_ops || + NULL == add->pages) + goto err; + + for (i = 0; i < count; i++) { + add->pages[i] = alloc_page(GFP_KERNEL | __GFP_HIGHMEM); + if (add->pages[i] == NULL) + goto err; + } + + add->index = 0; + add->count = count; + add->priv = priv; + + if (add->count + priv->used > priv->limit) + goto err; + + return add; + +err: + if (add->pages) + for (i = 0; i < count; i++) { + if (add->pages[i]) + __free_page(add->pages[i]); + } + kfree(add->pages); + kfree(add->grants); + kfree(add->map_ops); + kfree(add->unmap_ops); + kfree(add); + return NULL; +} + +static void gntdev_add_map(struct gntdev_priv *priv, struct grant_map *add) +{ + struct grant_map *map; + + list_for_each_entry(map, &priv->maps, next) { + if (add->index + add->count < map->index) { + list_add_tail(&add->next, &map->next); + goto done; + } + add->index = map->index + map->count; + } + list_add_tail(&add->next, &priv->maps); + +done: + priv->used += add->count; + gntdev_print_maps(priv, "[new]", add->index); +} + +static struct grant_map *gntdev_find_map_index(struct gntdev_priv *priv, + int index, int count) +{ + struct grant_map *map; + + list_for_each_entry(map, &priv->maps, next) { + if (map->index != index) + continue; + if (map->count != count) + continue; + return map; + } + return NULL; +} + +static struct grant_map *gntdev_find_map_vaddr(struct gntdev_priv *priv, + unsigned long vaddr) +{ + struct grant_map *map; + + list_for_each_entry(map, &priv->maps, next) { + if (!map->vma) + continue; + if (vaddr < map->vma->vm_start) + continue; + if (vaddr >= map->vma->vm_end) + continue; + return map; + } + return NULL; +} + +static int gntdev_del_map(struct grant_map *map) +{ + int i; + + if (map->vma) + return -EBUSY; + for (i = 0; i < map->count; i++) + if (map->unmap_ops[i].handle) + return -EBUSY; + + map->priv->used -= map->count; + list_del(&map->next); + return 0; +} + +static void gntdev_free_map(struct grant_map *map) +{ + int i; + + if (!map) + return; + + if (map->pages) + for (i = 0; i < map->count; i++) { + if (map->pages[i]) + __free_page(map->pages[i]); + } + kfree(map->pages); + kfree(map->grants); + kfree(map->map_ops); + kfree(map->unmap_ops); + kfree(map); +} + +/* ------------------------------------------------------------------ */ + +static int find_grant_ptes(pte_t *pte, pgtable_t token, + unsigned long addr, void *data) +{ + struct grant_map *map = data; + unsigned int pgnr = (addr - map->vma->vm_start) >> PAGE_SHIFT; + u64 pte_maddr; + + BUG_ON(pgnr >= map->count); + pte_maddr = arbitrary_virt_to_machine(pte).maddr; + + gnttab_set_map_op(&map->map_ops[pgnr], pte_maddr, + GNTMAP_contains_pte | map->flags, + map->grants[pgnr].ref, + map->grants[pgnr].domid); + gnttab_set_unmap_op(&map->unmap_ops[pgnr], pte_maddr, + GNTMAP_contains_pte | map->flags, + 0 /* handle */); + return 0; +} + +static int map_grant_pages(struct grant_map *map) +{ + int i, err = 0; + + pr_debug("map %d+%d\n", map->index, map->count); + err = gnttab_map_refs(map->map_ops, map->pages, map->count); + if (err) + return err; + + for (i = 0; i < map->count; i++) { + if (map->map_ops[i].status) + err = -EINVAL; + map->unmap_ops[i].handle = map->map_ops[i].handle; + } + return err; +} + +static int unmap_grant_pages(struct grant_map *map, int offset, int pages) +{ + int i, err = 0; + + pr_debug("map %d+%d [%d+%d]\n", map->index, map->count, offset, pages); + err = gnttab_unmap_refs(map->unmap_ops + offset, map->pages, pages); + if (err) + return err; + + for (i = 0; i < pages; i++) { + if (map->unmap_ops[offset+i].status) + err = -EINVAL; + map->unmap_ops[offset+i].handle = 0; + } + return err; +} + +/* ------------------------------------------------------------------ */ + +static void gntdev_vma_close(struct vm_area_struct *vma) +{ + struct grant_map *map = vma->vm_private_data; + + pr_debug("close %p\n", vma); + map->is_mapped = 0; + map->vma = NULL; + vma->vm_private_data = NULL; +} + +static int gntdev_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf) +{ + pr_debug("vaddr %p, pgoff %ld (shouldn't happen)\n", + vmf->virtual_address, vmf->pgoff); + vmf->flags = VM_FAULT_ERROR; + return 0; +} + +static struct vm_operations_struct gntdev_vmops = { + .close = gntdev_vma_close, + .fault = gntdev_vma_fault, +}; + +/* ------------------------------------------------------------------ */ + +static void mn_invl_range_start(struct mmu_notifier *mn, + struct mm_struct *mm, + unsigned long start, unsigned long end) +{ + struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn); + struct grant_map *map; + unsigned long mstart, mend; + int err; + + spin_lock(&priv->lock); + list_for_each_entry(map, &priv->maps, next) { + if (!map->vma) + continue; + if (!map->is_mapped) + continue; + if (map->vma->vm_start >= end) + continue; + if (map->vma->vm_end <= start) + continue; + mstart = max(start, map->vma->vm_start); + mend = min(end, map->vma->vm_end); + pr_debug("map %d+%d (%lx %lx), range %lx %lx, mrange %lx %lx\n", + map->index, map->count, + map->vma->vm_start, map->vma->vm_end, + start, end, mstart, mend); + err = unmap_grant_pages(map, + (mstart - map->vma->vm_start) >> PAGE_SHIFT, + (mend - mstart) >> PAGE_SHIFT); + WARN_ON(err); + } + spin_unlock(&priv->lock); +} + +static void mn_invl_page(struct mmu_notifier *mn, + struct mm_struct *mm, + unsigned long address) +{ + mn_invl_range_start(mn, mm, address, address + PAGE_SIZE); +} + +static void mn_release(struct mmu_notifier *mn, + struct mm_struct *mm) +{ + struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn); + struct grant_map *map; + int err; + + spin_lock(&priv->lock); + list_for_each_entry(map, &priv->maps, next) { + if (!map->vma) + continue; + pr_debug("map %d+%d (%lx %lx)\n", + map->index, map->count, + map->vma->vm_start, map->vma->vm_end); + err = unmap_grant_pages(map, /* offset */ 0, map->count); + WARN_ON(err); + } + spin_unlock(&priv->lock); +} + +struct mmu_notifier_ops gntdev_mmu_ops = { + .release = mn_release, + .invalidate_page = mn_invl_page, + .invalidate_range_start = mn_invl_range_start, +}; + +/* ------------------------------------------------------------------ */ + +static int gntdev_open(struct inode *inode, struct file *flip) +{ + struct gntdev_priv *priv; + int ret = 0; + + priv = kzalloc(sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + INIT_LIST_HEAD(&priv->maps); + spin_lock_init(&priv->lock); + priv->limit = limit; + + priv->mm = get_task_mm(current); + if (!priv->mm) { + kfree(priv); + return -ENOMEM; + } + priv->mn.ops = &gntdev_mmu_ops; + ret = mmu_notifier_register(&priv->mn, priv->mm); + mmput(priv->mm); + + if (ret) { + kfree(priv); + return ret; + } + + flip->private_data = priv; + pr_debug("priv %p\n", priv); + + return 0; +} + +static int gntdev_release(struct inode *inode, struct file *flip) +{ + struct gntdev_priv *priv = flip->private_data; + struct grant_map *map; + int err; + + pr_debug("priv %p\n", priv); + + spin_lock(&priv->lock); + while (!list_empty(&priv->maps)) { + map = list_entry(priv->maps.next, struct grant_map, next); + err = gntdev_del_map(map); + if (WARN_ON(err)) + gntdev_free_map(map); + + } + spin_unlock(&priv->lock); + + mmu_notifier_unregister(&priv->mn, priv->mm); + kfree(priv); + return 0; +} + +static long gntdev_ioctl_map_grant_ref(struct gntdev_priv *priv, + struct ioctl_gntdev_map_grant_ref __user *u) +{ + struct ioctl_gntdev_map_grant_ref op; + struct grant_map *map; + int err; + + if (copy_from_user(&op, u, sizeof(op)) != 0) + return -EFAULT; + pr_debug("priv %p, add %d\n", priv, op.count); + if (unlikely(op.count <= 0)) + return -EINVAL; + if (unlikely(op.count > priv->limit)) + return -EINVAL; + + err = -ENOMEM; + map = gntdev_alloc_map(priv, op.count); + if (!map) + return err; + if (copy_from_user(map->grants, &u->refs, + sizeof(map->grants[0]) * op.count) != 0) { + gntdev_free_map(map); + return err; + } + + spin_lock(&priv->lock); + gntdev_add_map(priv, map); + op.index = map->index << PAGE_SHIFT; + spin_unlock(&priv->lock); + + if (copy_to_user(u, &op, sizeof(op)) != 0) { + spin_lock(&priv->lock); + gntdev_del_map(map); + spin_unlock(&priv->lock); + gntdev_free_map(map); + return err; + } + return 0; +} + +static long gntdev_ioctl_unmap_grant_ref(struct gntdev_priv *priv, + struct ioctl_gntdev_unmap_grant_ref __user *u) +{ + struct ioctl_gntdev_unmap_grant_ref op; + struct grant_map *map; + int err = -ENOENT; + + if (copy_from_user(&op, u, sizeof(op)) != 0) + return -EFAULT; + pr_debug("priv %p, del %d+%d\n", priv, (int)op.index, (int)op.count); + + spin_lock(&priv->lock); + map = gntdev_find_map_index(priv, op.index >> PAGE_SHIFT, op.count); + if (map) + err = gntdev_del_map(map); + spin_unlock(&priv->lock); + if (!err) + gntdev_free_map(map); + return err; +} + +static long gntdev_ioctl_get_offset_for_vaddr(struct gntdev_priv *priv, + struct ioctl_gntdev_get_offset_for_vaddr __user *u) +{ + struct ioctl_gntdev_get_offset_for_vaddr op; + struct grant_map *map; + + if (copy_from_user(&op, u, sizeof(op)) != 0) + return -EFAULT; + pr_debug("priv %p, offset for vaddr %lx\n", priv, (unsigned long)op.vaddr); + + spin_lock(&priv->lock); + map = gntdev_find_map_vaddr(priv, op.vaddr); + if (map == NULL || + map->vma->vm_start != op.vaddr) { + spin_unlock(&priv->lock); + return -EINVAL; + } + op.offset = map->index << PAGE_SHIFT; + op.count = map->count; + spin_unlock(&priv->lock); + + if (copy_to_user(u, &op, sizeof(op)) != 0) + return -EFAULT; + return 0; +} + +static long gntdev_ioctl_set_max_grants(struct gntdev_priv *priv, + struct ioctl_gntdev_set_max_grants __user *u) +{ + struct ioctl_gntdev_set_max_grants op; + + if (copy_from_user(&op, u, sizeof(op)) != 0) + return -EFAULT; + pr_debug("priv %p, limit %d\n", priv, op.count); + if (op.count > limit) + return -E2BIG; + + spin_lock(&priv->lock); + priv->limit = op.count; + spin_unlock(&priv->lock); + return 0; +} + +static long gntdev_ioctl(struct file *flip, + unsigned int cmd, unsigned long arg) +{ + struct gntdev_priv *priv = flip->private_data; + void __user *ptr = (void __user *)arg; + + switch (cmd) { + case IOCTL_GNTDEV_MAP_GRANT_REF: + return gntdev_ioctl_map_grant_ref(priv, ptr); + + case IOCTL_GNTDEV_UNMAP_GRANT_REF: + return gntdev_ioctl_unmap_grant_ref(priv, ptr); + + case IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR: + return gntdev_ioctl_get_offset_for_vaddr(priv, ptr); + + case IOCTL_GNTDEV_SET_MAX_GRANTS: + return gntdev_ioctl_set_max_grants(priv, ptr); + + default: + pr_debug("priv %p, unknown cmd %x\n", priv, cmd); + return -ENOIOCTLCMD; + } + + return 0; +} + +static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma) +{ + struct gntdev_priv *priv = flip->private_data; + int index = vma->vm_pgoff; + int count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; + struct grant_map *map; + int err = -EINVAL; + + if ((vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_SHARED)) + return -EINVAL; + + pr_debug("map %d+%d at %lx (pgoff %lx)\n", + index, count, vma->vm_start, vma->vm_pgoff); + + spin_lock(&priv->lock); + map = gntdev_find_map_index(priv, index, count); + if (!map) + goto unlock_out; + if (map->vma) + goto unlock_out; + if (priv->mm != vma->vm_mm) { + printk(KERN_WARNING "Huh? Other mm?\n"); + goto unlock_out; + } + + vma->vm_ops = &gntdev_vmops; + + vma->vm_flags |= VM_RESERVED|VM_DONTCOPY|VM_DONTEXPAND|VM_PFNMAP; + + vma->vm_private_data = map; + map->vma = vma; + + map->flags = GNTMAP_host_map | GNTMAP_application_map; + if (!(vma->vm_flags & VM_WRITE)) + map->flags |= GNTMAP_readonly; + + spin_unlock(&priv->lock); + + err = apply_to_page_range(vma->vm_mm, vma->vm_start, + vma->vm_end - vma->vm_start, + find_grant_ptes, map); + if (err) { + printk(KERN_WARNING "find_grant_ptes() failure.\n"); + return err; + } + + err = map_grant_pages(map); + if (err) { + printk(KERN_WARNING "map_grant_pages() failure.\n"); + return err; + } + + map->is_mapped = 1; + + return 0; + +unlock_out: + spin_unlock(&priv->lock); + return err; +} + +static const struct file_operations gntdev_fops = { + .owner = THIS_MODULE, + .open = gntdev_open, + .release = gntdev_release, + .mmap = gntdev_mmap, + .unlocked_ioctl = gntdev_ioctl +}; + +static struct miscdevice gntdev_miscdev = { + .minor = MISC_DYNAMIC_MINOR, + .name = "xen/gntdev", + .fops = &gntdev_fops, +}; + +/* ------------------------------------------------------------------ */ + +static int __init gntdev_init(void) +{ + int err; + + if (!xen_domain()) + return -ENODEV; + + err = misc_register(&gntdev_miscdev); + if (err != 0) { + printk(KERN_ERR "Could not register gntdev device\n"); + return err; + } + return 0; +} + +static void __exit gntdev_exit(void) +{ + misc_deregister(&gntdev_miscdev); +} + +module_init(gntdev_init); +module_exit(gntdev_exit); + +/* ------------------------------------------------------------------ */ diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index 6c45318..9ef54eb 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -447,6 +447,52 @@ unsigned int gnttab_max_grant_frames(void) } EXPORT_SYMBOL_GPL(gnttab_max_grant_frames); +int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, + struct page **pages, unsigned int count) +{ + int i, ret; + pte_t *pte; + unsigned long mfn; + + ret = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, map_ops, count); + if (ret) + return ret; + + for (i = 0; i < count; i++) { + /* m2p override only supported for GNTMAP_contains_pte mappings */ + if (!(map_ops[i].flags & GNTMAP_contains_pte)) + continue; + pte = (pte_t *) (mfn_to_virt(PFN_DOWN(map_ops[i].host_addr)) + + (map_ops[i].host_addr & ~PAGE_MASK)); + mfn = pte_mfn(*pte); + ret = m2p_add_override(mfn, pages[i]); + if (ret) + return ret; + } + + return ret; +} +EXPORT_SYMBOL_GPL(gnttab_map_refs); + +int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, + struct page **pages, unsigned int count) +{ + int i, ret; + + ret = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap_ops, count); + if (ret) + return ret; + + for (i = 0; i < count; i++) { + ret = m2p_remove_override(pages[i]); + if (ret) + return ret; + } + + return ret; +} +EXPORT_SYMBOL_GPL(gnttab_unmap_refs); + static int gnttab_map(unsigned int start_idx, unsigned int end_idx) { struct gnttab_setup_table setup; diff --git a/include/xen/gntdev.h b/include/xen/gntdev.h new file mode 100644 index 0000000..eb23f41 --- /dev/null +++ b/include/xen/gntdev.h @@ -0,0 +1,119 @@ +/****************************************************************************** + * gntdev.h + * + * Interface to /dev/xen/gntdev. + * + * Copyright (c) 2007, D G Murray + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License version 2 + * as published by the Free Software Foundation; or, when distributed + * separately from the Linux kernel or incorporated into other + * software packages, subject to the following license: + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this source file (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, modify, + * merge, publish, distribute, sublicense, and/or sell copies of the Software, + * and to permit persons to whom the Software is furnished to do so, subject to + * the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS + * IN THE SOFTWARE. + */ + +#ifndef __LINUX_PUBLIC_GNTDEV_H__ +#define __LINUX_PUBLIC_GNTDEV_H__ + +struct ioctl_gntdev_grant_ref { + /* The domain ID of the grant to be mapped. */ + uint32_t domid; + /* The grant reference of the grant to be mapped. */ + uint32_t ref; +}; + +/* + * Inserts the grant references into the mapping table of an instance + * of gntdev. N.B. This does not perform the mapping, which is deferred + * until mmap() is called with @index as the offset. + */ +#define IOCTL_GNTDEV_MAP_GRANT_REF \ +_IOC(_IOC_NONE, 'G', 0, sizeof(struct ioctl_gntdev_map_grant_ref)) +struct ioctl_gntdev_map_grant_ref { + /* IN parameters */ + /* The number of grants to be mapped. */ + uint32_t count; + uint32_t pad; + /* OUT parameters */ + /* The offset to be used on a subsequent call to mmap(). */ + uint64_t index; + /* Variable IN parameter. */ + /* Array of grant references, of size @count. */ + struct ioctl_gntdev_grant_ref refs[1]; +}; + +/* + * Removes the grant references from the mapping table of an instance of + * of gntdev. N.B. munmap() must be called on the relevant virtual address(es) + * before this ioctl is called, or an error will result. + */ +#define IOCTL_GNTDEV_UNMAP_GRANT_REF \ +_IOC(_IOC_NONE, 'G', 1, sizeof(struct ioctl_gntdev_unmap_grant_ref)) +struct ioctl_gntdev_unmap_grant_ref { + /* IN parameters */ + /* The offset was returned by the corresponding map operation. */ + uint64_t index; + /* The number of pages to be unmapped. */ + uint32_t count; + uint32_t pad; +}; + +/* + * Returns the offset in the driver's address space that corresponds + * to @vaddr. This can be used to perform a munmap(), followed by an + * UNMAP_GRANT_REF ioctl, where no state about the offset is retained by + * the caller. The number of pages that were allocated at the same time as + * @vaddr is returned in @count. + * + * N.B. Where more than one page has been mapped into a contiguous range, the + * supplied @vaddr must correspond to the start of the range; otherwise + * an error will result. It is only possible to munmap() the entire + * contiguously-allocated range at once, and not any subrange thereof. + */ +#define IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR \ +_IOC(_IOC_NONE, 'G', 2, sizeof(struct ioctl_gntdev_get_offset_for_vaddr)) +struct ioctl_gntdev_get_offset_for_vaddr { + /* IN parameters */ + /* The virtual address of the first mapped page in a range. */ + uint64_t vaddr; + /* OUT parameters */ + /* The offset that was used in the initial mmap() operation. */ + uint64_t offset; + /* The number of pages mapped in the VM area that begins at @vaddr. */ + uint32_t count; + uint32_t pad; +}; + +/* + * Sets the maximum number of grants that may mapped at once by this gntdev + * instance. + * + * N.B. This must be called before any other ioctl is performed on the device. + */ +#define IOCTL_GNTDEV_SET_MAX_GRANTS \ +_IOC(_IOC_NONE, 'G', 3, sizeof(struct ioctl_gntdev_set_max_grants)) +struct ioctl_gntdev_set_max_grants { + /* IN parameter */ + /* The maximum number of grants that may be mapped at once. */ + uint32_t count; +}; + +#endif /* __LINUX_PUBLIC_GNTDEV_H__ */ diff --git a/include/xen/grant_table.h b/include/xen/grant_table.h index 9a73170..b1fab6b 100644 --- a/include/xen/grant_table.h +++ b/include/xen/grant_table.h @@ -37,10 +37,16 @@ #ifndef __ASM_GNTTAB_H__ #define __ASM_GNTTAB_H__ -#include <asm/xen/hypervisor.h> +#include <asm/page.h> + +#include <xen/interface/xen.h> #include <xen/interface/grant_table.h> + +#include <asm/xen/hypervisor.h> #include <asm/xen/grant_table.h> +#include <xen/features.h> + /* NR_GRANT_FRAMES must be less than or equal to that configured in Xen */ #define NR_GRANT_FRAMES 4 @@ -107,6 +113,37 @@ void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid, void gnttab_grant_foreign_transfer_ref(grant_ref_t, domid_t domid, unsigned long pfn); +static inline void +gnttab_set_map_op(struct gnttab_map_grant_ref *map, phys_addr_t addr, + uint32_t flags, grant_ref_t ref, domid_t domid) +{ + if (flags & GNTMAP_contains_pte) + map->host_addr = addr; + else if (xen_feature(XENFEAT_auto_translated_physmap)) + map->host_addr = __pa(addr); + else + map->host_addr = addr; + + map->flags = flags; + map->ref = ref; + map->dom = domid; +} + +static inline void +gnttab_set_unmap_op(struct gnttab_unmap_grant_ref *unmap, phys_addr_t addr, + uint32_t flags, grant_handle_t handle) +{ + if (flags & GNTMAP_contains_pte) + unmap->host_addr = addr; + else if (xen_feature(XENFEAT_auto_translated_physmap)) + unmap->host_addr = __pa(addr); + else + unmap->host_addr = addr; + + unmap->handle = handle; + unmap->dev_bus_addr = 0; +} + int arch_gnttab_map_shared(unsigned long *frames, unsigned long nr_gframes, unsigned long max_nr_gframes, struct grant_entry **__shared); @@ -118,4 +155,9 @@ unsigned int gnttab_max_grant_frames(void); #define gnttab_map_vaddr(map) ((void *)(map.host_virt_addr)) +int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, + struct page **pages, unsigned int count); +int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, + struct page **pages, unsigned int count); + #endif /* __ASM_GNTTAB_H__ */ |
