Re: [PATCH 21/22] mini-os: get physical memory map

[Samuel Thibault <samuel.thibault@ens-lyon.org>]

Juergen Gross, on Tue 23 Aug 2016 17:16:07 +0200, wrote:
> On HVMlite we have to look at the physical memory map to know which
> memory frames are usable.
> 
> In order to make life easier we define a dummy memory map for other
> domain types (pv and arm) which has just one entry with a maximum
> memory size.
> 
> Signed-off-by: Juergen Gross <jgross@suse.com>

Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>

> ---
>  arch/arm/mm.c         |  8 ++++++
>  arch/x86/mm.c         | 72 ++++++++++++++++++++++++++++++++++++++++++++++
>  arch/x86/setup.c      |  1 +
>  include/e820.h        | 48 +++++++++++++++++++++++++++++++
>  include/x86/arch_mm.h |  4 +++
>  mm.c                  | 79 ++++++++++++++++++++++++++++++++-------------------
>  6 files changed, 183 insertions(+), 29 deletions(-)
>  create mode 100644 include/e820.h
> 
> diff --git a/arch/arm/mm.c b/arch/arm/mm.c
> index dbde162..8c156c4 100644
> --- a/arch/arm/mm.c
> +++ b/arch/arm/mm.c
> @@ -7,6 +7,14 @@
>  #include <lib.h>
>  
>  uint32_t physical_address_offset;
> +struct e820entry e820_map[1] = {
> +    {
> +        .addr = 0,
> +        .size = ULONG_MAX - 1,
> +        .type = E820_RAM
> +    }
> +};
> +unsigned e820_entries = 1;
>  
>  unsigned long allocate_ondemand(unsigned long n, unsigned long alignment)
>  {
> diff --git a/arch/x86/mm.c b/arch/x86/mm.c
> index 762599d..8dd90b8 100644
> --- a/arch/x86/mm.c
> +++ b/arch/x86/mm.c
> @@ -43,6 +43,7 @@
>  #include <mini-os/types.h>
>  #include <mini-os/lib.h>
>  #include <mini-os/xmalloc.h>
> +#include <mini-os/e820.h>
>  #include <xen/memory.h>
>  
>  #ifdef MM_DEBUG
> @@ -63,6 +64,15 @@ extern char stack[];
>  extern void page_walk(unsigned long va);
>  
>  #ifdef CONFIG_PARAVIRT
> +struct e820entry e820_map[1] = {
> +    {
> +        .addr = 0,
> +        .size = ULONG_MAX - 1,
> +        .type = E820_RAM
> +    }
> +};
> +unsigned e820_entries = 1;
> +
>  void arch_mm_preinit(void *p)
>  {
>      start_info_t *si = p;
> @@ -102,10 +112,25 @@ desc_ptr idt_ptr =
>      .base = (unsigned long)&idt,
>  };
>  
> +struct e820entry e820_map[E820_MAX];
> +unsigned e820_entries;
> +
> +static char *e820_types[E820_TYPES] = {
> +    [E820_RAM]      = "RAM",
> +    [E820_RESERVED] = "Reserved",
> +    [E820_ACPI]     = "ACPI",
> +    [E820_NVS]      = "NVS",
> +    [E820_UNUSABLE] = "Unusable",
> +    [E820_PMEM]     = "PMEM"
> +};
> +
>  void arch_mm_preinit(void *p)
>  {
>      long ret;
>      domid_t domid = DOMID_SELF;
> +    struct xen_memory_map memmap;
> +    int i;
> +    unsigned long pfn, max = 0;
>  
>      pt_base = page_table_base;
>      first_free_pfn = PFN_UP(to_phys(&_end));
> @@ -116,6 +141,53 @@ void arch_mm_preinit(void *p)
>          do_exit();
>      }
>      last_free_pfn = ret;
> +
> +    memmap.nr_entries = E820_MAX;
> +    set_xen_guest_handle(memmap.buffer, e820_map);
> +    ret = HYPERVISOR_memory_op(XENMEM_memory_map, &memmap);
> +    if ( ret < 0 )
> +    {
> +        xprintk("could not get memory map\n");
> +        do_exit();
> +    }
> +    e820_entries = memmap.nr_entries;
> +
> +    for ( i = 0; i < e820_entries; i++ )
> +    {
> +        if ( e820_map[i].type != E820_RAM )
> +            continue;
> +        pfn = (e820_map[i].addr + e820_map[i].size) >> PAGE_SHIFT;
> +        if ( pfn > max )
> +            max = pfn;
> +    }
> +
> +    if ( max < last_free_pfn )
> +        last_free_pfn = max;
> +}
> +
> +void arch_print_memmap(void)
> +{
> +    int i;
> +    unsigned long from, to;
> +    char *type;
> +    char buf[12];
> +
> +    printk("Memory map:\n");
> +    for ( i = 0; i < e820_entries; i++ )
> +    {
> +        if ( e820_map[i].type >= E820_TYPES || !e820_types[e820_map[i].type] )
> +        {
> +            snprintf(buf, sizeof(buf), "%8x", e820_map[i].type);
> +            type = buf;
> +        }
> +        else
> +        {
> +            type = e820_types[e820_map[i].type];
> +        }
> +        from = e820_map[i].addr;
> +        to = from + e820_map[i].size - 1;
> +        printk("%012lx-%012lx: %s\n", from, to, type);
> +    }
>  }
>  #endif
>  
> diff --git a/arch/x86/setup.c b/arch/x86/setup.c
> index 948b08a..829b03c 100644
> --- a/arch/x86/setup.c
> +++ b/arch/x86/setup.c
> @@ -150,6 +150,7 @@ static void print_start_of_day(void *p)
>      printk("       flags: 0x%x\n", (unsigned int)si->flags);
>      printk("    cmd_line: %s\n", cmdline);
>      printk("       stack: %p-%p\n", stack, stack + sizeof(stack));
> +    arch_print_memmap();
>  }
>  #endif
>  
> diff --git a/include/e820.h b/include/e820.h
> new file mode 100644
> index 0000000..920551c
> --- /dev/null
> +++ b/include/e820.h
> @@ -0,0 +1,48 @@
> +/* -*-  Mode:C; c-basic-offset:4; tab-width:4 -*-
> + *
> + * (C) 2016 - Juergen Gross, SUSE Linux GmbH
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a copy
> + * of this software and associated documentation files (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 __E820_HEADER
> +#define __E820_HEADER
> +
> +/* PC BIOS standard E820 types and structure. */
> +#define E820_RAM          1
> +#define E820_RESERVED     2
> +#define E820_ACPI         3
> +#define E820_NVS          4
> +#define E820_UNUSABLE     5
> +#define E820_PMEM         7
> +#define E820_TYPES        8
> +
> +struct __packed e820entry {
> +    uint64_t addr;
> +    uint64_t size;
> +    uint32_t type;
> +};
> +
> +/* Maximum number of entries. */
> +#define E820_MAX          128
> +
> +extern struct e820entry e820_map[];
> +extern unsigned e820_entries;
> +
> +#endif /*__E820_HEADER*/
> diff --git a/include/x86/arch_mm.h b/include/x86/arch_mm.h
> index 9372f1e..ab8a53e 100644
> --- a/include/x86/arch_mm.h
> +++ b/include/x86/arch_mm.h
> @@ -279,6 +279,10 @@ pgentry_t *need_pgt(unsigned long addr);
>  void arch_mm_preinit(void *p);
>  unsigned long alloc_virt_kernel(unsigned n_pages);
>  
> +#ifndef CONFIG_PARAVIRT
> +void arch_print_memmap(void);
> +#endif
> +
>  #endif
>  
>  #endif /* _ARCH_MM_H_ */
> diff --git a/mm.c b/mm.c
> index c76be7f..932ceeb 100644
> --- a/mm.c
> +++ b/mm.c
> @@ -43,6 +43,7 @@
>  #include <mini-os/types.h>
>  #include <mini-os/lib.h>
>  #include <mini-os/xmalloc.h>
> +#include <mini-os/e820.h>
>  
>  /*********************
>   * ALLOCATION BITMAP
> @@ -147,10 +148,14 @@ static chunk_head_t  free_tail[FREELIST_SIZE];
>   */
>  static void init_page_allocator(unsigned long min, unsigned long max)
>  {
> -    int i;
> +    int i, m;
>      unsigned long range;
> +    unsigned long r_min, r_max;
>      chunk_head_t *ch;
>      chunk_tail_t *ct;
> +
> +    printk("MM: Initialise page allocator for %lx(%lx)-%lx(%lx)\n",
> +           (u_long)to_virt(min), min, (u_long)to_virt(max), max);
>      for ( i = 0; i < FREELIST_SIZE; i++ )
>      {
>          free_head[i]       = &free_tail[i];
> @@ -166,38 +171,57 @@ static void init_page_allocator(unsigned long min, unsigned long max)
>      mm_alloc_bitmap_size  = round_pgup(mm_alloc_bitmap_size);
>      mm_alloc_bitmap = (unsigned long *)to_virt(min);
>      min         += mm_alloc_bitmap_size;
> -    range        = max - min;
>  
>      /* All allocated by default. */
>      memset(mm_alloc_bitmap, ~0, mm_alloc_bitmap_size);
> -    /* Free up the memory we've been given to play with. */
> -    map_free(PHYS_PFN(min), range>>PAGE_SHIFT);
>  
> -    /* The buddy lists are addressed in high memory. */
> -    min = (unsigned long) to_virt(min);
> -    max = (unsigned long) to_virt(max);
> -
> -    while ( range != 0 )
> +    for ( m = 0; m < e820_entries; m++ )
>      {
> -        /*
> -         * Next chunk is limited by alignment of min, but also
> -         * must not be bigger than remaining range.
> -         */
> -        for ( i = PAGE_SHIFT; (1UL<<(i+1)) <= range; i++ )
> -            if ( min & (1UL<<i) ) break;
> +        if ( e820_map[m].type != E820_RAM )
> +            continue;
> +        if ( e820_map[m].addr + e820_map[m].size >= ULONG_MAX )
> +            BUG();
>  
> +        r_min = e820_map[m].addr;
> +        r_max = r_min + e820_map[m].size;
> +        if ( r_max <= min || r_min >= max )
> +            continue;
> +        if ( r_min < min )
> +            r_min = min;
> +        if ( r_max > max )
> +            r_max = max;
>  
> -        ch = (chunk_head_t *)min;
> -        min   += (1UL<<i);
> -        range -= (1UL<<i);
> -        ct = (chunk_tail_t *)min-1;
> -        i -= PAGE_SHIFT;
> -        ch->level       = i;
> -        ch->next        = free_head[i];
> -        ch->pprev       = &free_head[i];
> -        ch->next->pprev = &ch->next;
> -        free_head[i]    = ch;
> -        ct->level       = i;
> +        printk("    Adding memory range %lx-%lx\n", r_min, r_max);
> +
> +        /* The buddy lists are addressed in high memory. */
> +        r_min = (unsigned long)to_virt(r_min);
> +        r_max = (unsigned long)to_virt(r_max);
> +        range = r_max - r_min;
> +
> +        /* Free up the memory we've been given to play with. */
> +        map_free(PHYS_PFN(r_min), range >> PAGE_SHIFT);
> +
> +        while ( range != 0 )
> +        {
> +            /*
> +             * Next chunk is limited by alignment of min, but also
> +             * must not be bigger than remaining range.
> +             */
> +            for ( i = PAGE_SHIFT; (1UL << (i + 1)) <= range; i++ )
> +                if ( r_min & (1UL << i) ) break;
> +
> +            ch = (chunk_head_t *)r_min;
> +            r_min += 1UL << i;
> +            range -= 1UL << i;
> +            ct = (chunk_tail_t *)r_min - 1;
> +            i -= PAGE_SHIFT;
> +            ch->level       = i;
> +            ch->next        = free_head[i];
> +            ch->pprev       = &free_head[i];
> +            ch->next->pprev = &ch->next;
> +            free_head[i]    = ch;
> +            ct->level       = i;
> +        }
>      }
>  
>      mm_alloc_bitmap_remap();
> @@ -377,9 +401,6 @@ void init_mm(void)
>      /*
>       * now we can initialise the page allocator
>       */
> -    printk("MM: Initialise page allocator for %lx(%lx)-%lx(%lx)\n",
> -           (u_long)to_virt(PFN_PHYS(start_pfn)), (u_long)PFN_PHYS(start_pfn),
> -           (u_long)to_virt(PFN_PHYS(max_pfn)), (u_long)PFN_PHYS(max_pfn));
>      init_page_allocator(PFN_PHYS(start_pfn), PFN_PHYS(max_pfn));
>      printk("MM: done\n");
>  
> -- 
> 2.6.6
> 

-- 
Samuel
 Les roots ne sont plus ce qu'ils étaient...Maintenant il sont dioxinés,
 c'est de la m... ! Avant on les élevaient avec du bon unix mais ça été
 remplacé par des farines industrielles nouvelles technologies (NT).
 -+- JdK in NPC : Exigez un root élevé sous la mère ! -+-

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