[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-ia64-devel] [PATCH][RFC]copy_from/to_guest
Hi all, This patch fixes the copy_from/to_guest problem. As Akio reported, modularised netback causes dom0's down. The following process is happened in gnttab_transfer()@ xen/common/grant_table.c: gnttab_transfer() => steal_page() => assign_domain_page_cmpxchg_rel() => domain_page_flush() => domain_flush_vtlb_all() // all TLBs are flushed ... => __copy_to_guest_offset() // always fail to copy The embedded netback module has no problem because it uses TR pinned data. But modularised one is out of TR. So copy_from/to_guest issue must be solved in order to modularise drivers. Attached patch fixes copy_from/to_guest issue for modularized netback. But I think this implementation is not beautiful. Thanks, Kouya Signed-off-by: Kouya SHIMURA <kouya@xxxxxxxxxxxxxx> diff -r 15498beef5d8 linux-2.6-xen-sparse/arch/ia64/xen/hypervisor.c --- a/linux-2.6-xen-sparse/arch/ia64/xen/hypervisor.c Tue Aug 08 14:42:34 2006 -0600 +++ b/linux-2.6-xen-sparse/arch/ia64/xen/hypervisor.c Thu Aug 10 21:25:22 2006 +0900 @@ -371,6 +371,8 @@ int int HYPERVISOR_grant_table_op(unsigned int cmd, void *uop, unsigned int count) { + __u64 va1,va2,pa1,pa2; + if (cmd == GNTTABOP_map_grant_ref) { unsigned int i; for (i = 0; i < count; i++) { @@ -378,8 +380,27 @@ HYPERVISOR_grant_table_op(unsigned int c (struct gnttab_map_grant_ref*)uop + i); } } - - return ____HYPERVISOR_grant_table_op(cmd, uop, count); + va1 = (__u64)uop & PAGE_MASK; + pa1 = pa2 = 0; + if ((REGION_NUMBER(va1) == 5) && + ((va1 - KERNEL_START) >= KERNEL_TR_PAGE_SIZE)) { + pa1 = ia64_tpa(va1); + if (cmd <= GNTTABOP_transfer) { + static uint32_t uop_size[GNTTABOP_transfer+1] = { + sizeof(struct gnttab_map_grant_ref), + sizeof(struct gnttab_unmap_grant_ref), + sizeof(struct gnttab_setup_table), + sizeof(struct gnttab_dump_table), + sizeof(struct gnttab_transfer), + }; + va2 = ((__u64)uop + uop_size[cmd]*count - 1) & PAGE_MASK; + if (va1 != va2) { + BUG_ON (va2 > va1 + PAGE_SIZE); // maximum size of uop is 2pages + pa2 = ia64_tpa(va2); + } + } + } + return ____HYPERVISOR_grant_table_op(cmd, uop, count, pa1, pa2); } EXPORT_SYMBOL(HYPERVISOR_grant_table_op); diff -r 15498beef5d8 linux-2.6-xen-sparse/include/asm-ia64/hypercall.h --- a/linux-2.6-xen-sparse/include/asm-ia64/hypercall.h Tue Aug 08 14:42:34 2006 -0600 +++ b/linux-2.6-xen-sparse/include/asm-ia64/hypercall.h Thu Aug 10 21:25:22 2006 +0900 @@ -275,9 +275,9 @@ HYPERVISOR_physdev_op( //XXX __HYPERVISOR_grant_table_op is used for this hypercall constant. static inline int ____HYPERVISOR_grant_table_op( - unsigned int cmd, void *uop, unsigned int count) -{ - return _hypercall3(int, grant_table_op, cmd, uop, count); + unsigned int cmd, void *uop, unsigned int count, unsigned long pa1, unsigned long pa2) +{ + return _hypercall5(int, grant_table_op, cmd, uop, count, pa1, pa2); } int HYPERVISOR_grant_table_op(unsigned int cmd, void *uop, unsigned int count); diff -r 15498beef5d8 xen/arch/ia64/xen/hypercall.c --- a/xen/arch/ia64/xen/hypercall.c Tue Aug 08 14:42:34 2006 -0600 +++ b/xen/arch/ia64/xen/hypercall.c Thu Aug 10 21:25:22 2006 +0900 @@ -101,6 +101,13 @@ xen_hypercall (struct pt_regs *regs) xen_hypercall (struct pt_regs *regs) { uint32_t cmd = (uint32_t)regs->r2; + struct vcpu *v = current; + + if (cmd == __HYPERVISOR_grant_table_op) { + v->arch.hypercall_param.va = regs->r15; + v->arch.hypercall_param.pa1 = regs->r17; + v->arch.hypercall_param.pa2 = regs->r18; + } if (cmd < nr_hypercalls) regs->r8 = (*ia64_hypercall_table[cmd])( @@ -113,6 +120,7 @@ xen_hypercall (struct pt_regs *regs) else regs->r8 = -ENOSYS; + v->arch.hypercall_param.va = 0; return IA64_NO_FAULT; } diff -r 15498beef5d8 xen/arch/ia64/xen/vcpu.c --- a/xen/arch/ia64/xen/vcpu.c Tue Aug 08 14:42:34 2006 -0600 +++ b/xen/arch/ia64/xen/vcpu.c Thu Aug 10 21:25:22 2006 +0900 @@ -2215,3 +2215,26 @@ IA64FAULT vcpu_ptr_i(VCPU *vcpu,UINT64 v return IA64_NO_FAULT; } + +int ia64_map_hypercall_param(void) +{ + struct vcpu *v = current; + u64 vaddr = v->arch.hypercall_param.va & PAGE_MASK; + u64 pteval, logps, itir; + struct p2m_entry entry; + + if (v->arch.hypercall_param.va == 0) + return FALSE; + itir = PAGE_SHIFT<<2; + pteval = (v->arch.hypercall_param.pa1 & _PAGE_PPN_MASK)|__DIRTY_BITS |_PAGE_PL_2 |_PAGE_AR_RWX; + pteval = translate_domain_pte(pteval, vaddr, itir, &logps, &entry); + vcpu_itc_no_srlz(current, 2, vaddr, pteval, -1UL, PAGE_SHIFT); + if (v->arch.hypercall_param.pa2) { + vaddr += PAGE_SIZE; + pteval = (v->arch.hypercall_param.pa2 & _PAGE_PPN_MASK)|__DIRTY_BITS |_PAGE_PL_2 |_PAGE_AR_RWX; + pteval = translate_domain_pte(pteval, vaddr, itir, &logps, &entry); + vcpu_itc_no_srlz(current, 2, vaddr, pteval, -1UL, PAGE_SHIFT); + } + ia64_srlz_d(); + return TRUE; +} diff -r 15498beef5d8 xen/include/asm-ia64/domain.h --- a/xen/include/asm-ia64/domain.h Tue Aug 08 14:42:34 2006 -0600 +++ b/xen/include/asm-ia64/domain.h Thu Aug 10 21:25:22 2006 +0900 @@ -142,6 +142,12 @@ struct arch_domain { (sizeof(vcpu_info_t) * (v)->vcpu_id + \ offsetof(vcpu_info_t, evtchn_upcall_mask)) +struct hypercall_param { + unsigned long va; + unsigned long pa1; + unsigned long pa2; +}; + struct arch_vcpu { /* Save the state of vcpu. This is the first entry to speed up accesses. */ @@ -185,6 +191,9 @@ struct arch_vcpu { char irq_new_pending; char irq_new_condition; // vpsr.i/vtpr change, check for pending VHPI char hypercall_continuation; + + struct hypercall_param hypercall_param; // used to remap a hypercall parameter + //for phycial emulation unsigned long old_rsc; int mode_flags; diff -r 15498beef5d8 xen/include/asm-ia64/uaccess.h --- a/xen/include/asm-ia64/uaccess.h Tue Aug 08 14:42:34 2006 -0600 +++ b/xen/include/asm-ia64/uaccess.h Thu Aug 10 21:25:22 2006 +0900 @@ -211,16 +211,28 @@ extern unsigned long __must_check __copy extern unsigned long __must_check __copy_user (void __user *to, const void __user *from, unsigned long count); +extern int ia64_map_hypercall_param(void); + static inline unsigned long __copy_to_user (void __user *to, const void *from, unsigned long count) { - return __copy_user(to, (void __user *) from, count); + unsigned long len; + len = __copy_user(to, (void __user *) from, count); + if (len == 0) return 0; + if (ia64_map_hypercall_param()) + len = __copy_user(to, (void __user *) from, count); /* retry */ + return len; } static inline unsigned long __copy_from_user (void *to, const void __user *from, unsigned long count) { - return __copy_user((void __user *) to, from, count); + unsigned long len; + len = __copy_user((void __user *) to, from, count); + if (len == 0) return 0; + if (ia64_map_hypercall_param()) + len = __copy_user((void __user *) to, from, count); /* retry */ + return len; } #define __copy_to_user_inatomic __copy_to_user _______________________________________________ Xen-ia64-devel mailing list Xen-ia64-devel@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-ia64-devel
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