helper2.c

qemu虚拟机代码

        if (pde & PG_PSE_MASK) {
            /* 2 MB page */
            page_size = 2048 * 1024;
            ptep ^= PG_NX_MASK;
            if ((ptep & PG_NX_MASK) && is_write1 == 2)
                goto do_fault_protect;
            if (is_user) {
                if (!(ptep & PG_USER_MASK))
                    goto do_fault_protect;
                if (is_write && !(ptep & PG_RW_MASK))
                    goto do_fault_protect;
            } else {
                if ((env->cr[0] & CR0_WP_MASK) && 
                    is_write && !(ptep & PG_RW_MASK)) 
                    goto do_fault_protect;
            }
            is_dirty = is_write && !(pde & PG_DIRTY_MASK);
            if (!(pde & PG_ACCESSED_MASK) || is_dirty) {
                pde |= PG_ACCESSED_MASK;
                if (is_dirty)
                    pde |= PG_DIRTY_MASK;
                stl_phys_notdirty(pde_addr, pde);
            }
            /* align to page_size */
            pte = pde & ((PHYS_ADDR_MASK & ~(page_size - 1)) | 0xfff); 
            virt_addr = addr & ~(page_size - 1);
        } else {
            /* 4 KB page */
            if (!(pde & PG_ACCESSED_MASK)) {
                pde |= PG_ACCESSED_MASK;
                stl_phys_notdirty(pde_addr, pde);
            }
            pte_addr = ((pde & PHYS_ADDR_MASK) + (((addr >> 12) & 0x1ff) << 3)) &
                env->a20_mask;
            pte = ldq_phys(pte_addr);
            if (!(pte & PG_PRESENT_MASK)) {
                error_code = 0;
                goto do_fault;
            }
            if (!(env->efer & MSR_EFER_NXE) && (pte & PG_NX_MASK)) {
                error_code = PG_ERROR_RSVD_MASK;
                goto do_fault;
            }
            /* combine pde and pte nx, user and rw protections */
            ptep &= pte ^ PG_NX_MASK;
            ptep ^= PG_NX_MASK;
            if ((ptep & PG_NX_MASK) && is_write1 == 2)
                goto do_fault_protect; 
            if (is_user) {
                if (!(ptep & PG_USER_MASK))
                    goto do_fault_protect;
                if (is_write && !(ptep & PG_RW_MASK))
                    goto do_fault_protect;
            } else {
                if ((env->cr[0] & CR0_WP_MASK) &&
                    is_write && !(ptep & PG_RW_MASK)) 
                    goto do_fault_protect;
            }
            is_dirty = is_write && !(pte & PG_DIRTY_MASK);
            if (!(pte & PG_ACCESSED_MASK) || is_dirty) {
                pte |= PG_ACCESSED_MASK;
                if (is_dirty)
                    pte |= PG_DIRTY_MASK;
                stl_phys_notdirty(pte_addr, pte);
            }
            page_size = 4096;
            virt_addr = addr & ~0xfff;
            pte = pte & (PHYS_ADDR_MASK | 0xfff);
        }
    } else {
        uint32_t pde;

        /* page directory entry */
        pde_addr = ((env->cr[3] & ~0xfff) + ((addr >> 20) & ~3)) & 
            env->a20_mask;
        pde = ldl_phys(pde_addr);
        if (!(pde & PG_PRESENT_MASK)) {
            error_code = 0;
            goto do_fault;
        }
        /* if PSE bit is set, then we use a 4MB page */
        if ((pde & PG_PSE_MASK) && (env->cr[4] & CR4_PSE_MASK)) {
            page_size = 4096 * 1024;
            if (is_user) {
                if (!(pde & PG_USER_MASK))
                    goto do_fault_protect;
                if (is_write && !(pde & PG_RW_MASK))
                    goto do_fault_protect;
            } else {
                if ((env->cr[0] & CR0_WP_MASK) && 
                    is_write && !(pde & PG_RW_MASK)) 
                    goto do_fault_protect;
            }
            is_dirty = is_write && !(pde & PG_DIRTY_MASK);
            if (!(pde & PG_ACCESSED_MASK) || is_dirty) {
                pde |= PG_ACCESSED_MASK;
                if (is_dirty)
                    pde |= PG_DIRTY_MASK;
                stl_phys_notdirty(pde_addr, pde);
            }
        
            pte = pde & ~( (page_size - 1) & ~0xfff); /* align to page_size */
            ptep = pte;
            virt_addr = addr & ~(page_size - 1);
        } else {
            if (!(pde & PG_ACCESSED_MASK)) {
                pde |= PG_ACCESSED_MASK;
                stl_phys_notdirty(pde_addr, pde);
            }

            /* page directory entry */
            pte_addr = ((pde & ~0xfff) + ((addr >> 10) & 0xffc)) & 
                env->a20_mask;
            pte = ldl_phys(pte_addr);
            if (!(pte & PG_PRESENT_MASK)) {
                error_code = 0;
                goto do_fault;
            }
            /* combine pde and pte user and rw protections */
            ptep = pte & pde;
            if (is_user) {
                if (!(ptep & PG_USER_MASK))
                    goto do_fault_protect;
                if (is_write && !(ptep & PG_RW_MASK))
                    goto do_fault_protect;
            } else {
                if ((env->cr[0] & CR0_WP_MASK) &&
                    is_write && !(ptep & PG_RW_MASK)) 
                    goto do_fault_protect;
            }
            is_dirty = is_write && !(pte & PG_DIRTY_MASK);
            if (!(pte & PG_ACCESSED_MASK) || is_dirty) {
                pte |= PG_ACCESSED_MASK;
                if (is_dirty)
                    pte |= PG_DIRTY_MASK;
                stl_phys_notdirty(pte_addr, pte);
            }
            page_size = 4096;
            virt_addr = addr & ~0xfff;
        }
    }
    /* the page can be put in the TLB */
    prot = PAGE_READ;
    if (!(ptep & PG_NX_MASK))
        prot |= PAGE_EXEC;
    if (pte & PG_DIRTY_MASK) {
        /* only set write access if already dirty... otherwise wait
           for dirty access */
        if (is_user) {
            if (ptep & PG_RW_MASK)
                prot |= PAGE_WRITE;
        } else {
            if (!(env->cr[0] & CR0_WP_MASK) ||
                (ptep & PG_RW_MASK))
                prot |= PAGE_WRITE;
        }
    }
 do_mapping:
    pte = pte & env->a20_mask;

    /* Even if 4MB pages, we map only one 4KB page in the cache to
       avoid filling it too fast */
    page_offset = (addr & TARGET_PAGE_MASK) & (page_size - 1);
    paddr = (pte & TARGET_PAGE_MASK) + page_offset;
    vaddr = virt_addr + page_offset;
    
    ret = tlb_set_page_exec(env, vaddr, paddr, prot, is_user, is_softmmu);
    return ret;
 do_fault_protect:
    error_code = PG_ERROR_P_MASK;
 do_fault:
    env->cr[2] = addr;
    error_code |= (is_write << PG_ERROR_W_BIT);
    if (is_user)
        error_code |= PG_ERROR_U_MASK;
    if (is_write1 == 2 && 
        (env->efer & MSR_EFER_NXE) && 
        (env->cr[4] & CR4_PAE_MASK))
        error_code |= PG_ERROR_I_D_MASK;
    env->error_code = error_code;
    env->exception_index = EXCP0E_PAGE;
    return 1;
}

target_ulong cpu_get_phys_page_debug(CPUState *env, target_ulong addr)
{
    uint32_t pde_addr, pte_addr;
    uint32_t pde, pte, paddr, page_offset, page_size;

    if (env->cr[4] & CR4_PAE_MASK) {
        uint32_t pdpe_addr, pde_addr, pte_addr;
        uint32_t pdpe;

        /* XXX: we only use 32 bit physical addresses */
#ifdef TARGET_X86_64
        if (env->hflags & HF_LMA_MASK) {
            uint32_t pml4e_addr, pml4e;
            int32_t sext;

            /* test virtual address sign extension */
            sext = (int64_t)addr >> 47;
            if (sext != 0 && sext != -1)
                return -1;
            
            pml4e_addr = ((env->cr[3] & ~0xfff) + (((addr >> 39) & 0x1ff) << 3)) & 
                env->a20_mask;
            pml4e = ldl_phys(pml4e_addr);
            if (!(pml4e & PG_PRESENT_MASK))
                return -1;
            
            pdpe_addr = ((pml4e & ~0xfff) + (((addr >> 30) & 0x1ff) << 3)) & 
                env->a20_mask;
            pdpe = ldl_phys(pdpe_addr);
            if (!(pdpe & PG_PRESENT_MASK))
                return -1;
        } else 
#endif
        {
            pdpe_addr = ((env->cr[3] & ~0x1f) + ((addr >> 30) << 3)) & 
                env->a20_mask;
            pdpe = ldl_phys(pdpe_addr);
            if (!(pdpe & PG_PRESENT_MASK))
                return -1;
        }

        pde_addr = ((pdpe & ~0xfff) + (((addr >> 21) & 0x1ff) << 3)) &
            env->a20_mask;
        pde = ldl_phys(pde_addr);
        if (!(pde & PG_PRESENT_MASK)) {
            return -1;
        }
        if (pde & PG_PSE_MASK) {
            /* 2 MB page */
            page_size = 2048 * 1024;
            pte = pde & ~( (page_size - 1) & ~0xfff); /* align to page_size */
        } else {
            /* 4 KB page */
            pte_addr = ((pde & ~0xfff) + (((addr >> 12) & 0x1ff) << 3)) &
                env->a20_mask;
            page_size = 4096;
            pte = ldl_phys(pte_addr);
        }
    } else {
        if (!(env->cr[0] & CR0_PG_MASK)) {
            pte = addr;
            page_size = 4096;
        } else {
            /* page directory entry */
            pde_addr = ((env->cr[3] & ~0xfff) + ((addr >> 20) & ~3)) & env->a20_mask;
            pde = ldl_phys(pde_addr);
            if (!(pde & PG_PRESENT_MASK)) 
                return -1;
            if ((pde & PG_PSE_MASK) && (env->cr[4] & CR4_PSE_MASK)) {
                pte = pde & ~0x003ff000; /* align to 4MB */
                page_size = 4096 * 1024;
            } else {
                /* page directory entry */
                pte_addr = ((pde & ~0xfff) + ((addr >> 10) & 0xffc)) & env->a20_mask;
                pte = ldl_phys(pte_addr);
                if (!(pte & PG_PRESENT_MASK))
                    return -1;
                page_size = 4096;
            }
        }
        pte = pte & env->a20_mask;
    }

    page_offset = (addr & TARGET_PAGE_MASK) & (page_size - 1);
    paddr = (pte & TARGET_PAGE_MASK) + page_offset;
    return paddr;
}
#endif /* !CONFIG_USER_ONLY */

#if defined(USE_CODE_COPY)
struct fpstate {
    uint16_t fpuc;
    uint16_t dummy1;
    uint16_t fpus;
    uint16_t dummy2;
    uint16_t fptag;
    uint16_t dummy3;

    uint32_t fpip;
    uint32_t fpcs;
    uint32_t fpoo;
    uint32_t fpos;
    uint8_t fpregs1[8 * 10];
};

void restore_native_fp_state(CPUState *env)
{
    int fptag, i, j;
    struct fpstate fp1, *fp = &fp1;
    
    fp->fpuc = env->fpuc;
    fp->fpus = (env->fpus & ~0x3800) | (env->fpstt & 0x7) << 11;
    fptag = 0;
    for (i=7; i>=0; i--) {
	fptag <<= 2;
	if (env->fptags[i]) {
            fptag |= 3;
        } else {
            /* the FPU automatically computes it */
        }
    }
    fp->fptag = fptag;
    j = env->fpstt;
    for(i = 0;i < 8; i++) {
        memcpy(&fp->fpregs1[i * 10], &env->fpregs[j].d, 10);
        j = (j + 1) & 7;
    }
    asm volatile ("frstor %0" : "=m" (*fp));
    env->native_fp_regs = 1;
}
 
void save_native_fp_state(CPUState *env)
{
    int fptag, i, j;
    uint16_t fpuc;
    struct fpstate fp1, *fp = &fp1;

    asm volatile ("fsave %0" : : "m" (*fp));
    env->fpuc = fp->fpuc;
    env->fpstt = (fp->fpus >> 11) & 7;
    env->fpus = fp->fpus & ~0x3800;
    fptag = fp->fptag;
    for(i = 0;i < 8; i++) {
        env->fptags[i] = ((fptag & 3) == 3);
        fptag >>= 2;
    }
    j = env->fpstt;
    for(i = 0;i < 8; i++) {
        memcpy(&env->fpregs[j].d, &fp->fpregs1[i * 10], 10);
        j = (j + 1) & 7;
    }
    /* we must restore the default rounding state */
    /* XXX: we do not restore the exception state */
    fpuc = 0x037f | (env->fpuc & (3 << 10));
    asm volatile("fldcw %0" : : "m" (fpuc));
    env->native_fp_regs = 0;
}
#endif