On Tue, Nov 12, 2013 at 01:45:51PM +0100, Igor Mammedov wrote:
> On Sun, 10 Nov 2013 18:47:53 -0200
> Marcelo Tosatti <mtosa...@redhat.com> wrote:
>
> [...]
>
> > @@ -1177,10 +1182,50 @@ FWCfgState *pc_memory_init(MemoryRegion
> > *system_memory,
> > e820_add_entry(0, below_4g_mem_size, E820_RAM);
> > if (above_4g_mem_size > 0) {
> > ram_above_4g = g_malloc(sizeof(*ram_above_4g));
> it is a memory leak when "ram-above-4g" is not created
>
> > - memory_region_init_alias(ram_above_4g, NULL, "ram-above-4g", ram,
> > - below_4g_mem_size, above_4g_mem_size);
> > - memory_region_add_subregion(system_memory, 0x100000000ULL,
> > + /*
> > + *
> > + * If 1GB hugepages are used to back guest RAM, map guest address
> > + * space in the range [ramsize,ramsize+holesize] to the ram block
> > + * range [holestart, 4GB]
> > + *
> > + * 0 h 4G
> > [ramsize,ramsize+holesize]
> > + *
> > + * guest-addr-space [ ] [ ][xxx]
> > + * /----------/
> > + * contiguous-ram-block [ ][xxx][ ]
> > + *
> > + * So that memory beyond 4GB is aligned on a 1GB boundary,
> > + * at the host physical address space.
> > + *
> > + */
> > + if (guest_info->gb_align) {
> > + uint64_t holesize = 0x100000000ULL - below_4g_mem_size;
> > + uint64_t piecetwosize = holesize - align_offset;
> > +
> > + assert(piecetwosize <= holesize);
> > +
> > + if ((above_4g_mem_size - piecetwosize) > 0) {
> here is integer overflow,
> reproducable with: -mem-path /var/lib/hugetlbfs/global/pagesize-1GB -m 3600
Gah.
>
>
> > + memory_region_init_alias(ram_above_4g, NULL,
> > "ram-above-4g",
> > + ram, 0x100000000ULL,
> > + above_4g_mem_size - piecetwosize);
> > + memory_region_add_subregion(system_memory, 0x100000000ULL,
> > + ram_above_4g);
> > + }
> > +
> > + ram_above_4g_piecetwo =
> > g_malloc(sizeof(*ram_above_4g_piecetwo));
> > + memory_region_init_alias(ram_above_4g_piecetwo, NULL,
> > + "ram-above-4g-piecetwo", ram,
> > + 0x100000000ULL - holesize,
> > piecetwosize);
> > + memory_region_add_subregion(system_memory,
> > + 0x100000000ULL +
> > + above_4g_mem_size - piecetwosize,
> is there a guaranty that "ram-above-4g-piecetwo" will be mapped immediately
> after "ram-above-4g" without any gap?
Yes:
Length of piece one alias: above_4g_mem_size - piecetwosize
Start address of piecetwo: 0x100000000ULL + above_4g_mem_size - piecetwosize
> if there is no then you might need to change how e820_add_entry() for high ram
> is handled and possibly CMOS value as well.
>
> > + ram_above_4g_piecetwo);
> > + } else {
> > + memory_region_init_alias(ram_above_4g, NULL, "ram-above-4g",
> > ram,
> > + below_4g_mem_size, above_4g_mem_size);
> > + memory_region_add_subregion(system_memory, 0x100000000ULL,
> > ram_above_4g);
> > + }
> > e820_add_entry(0x100000000ULL, above_4g_mem_size, E820_RAM);
> > }
> [...]
> --
> Regards,
> Igor
