On Tue, 5 Nov 2013 23:55:43 -0200
Marcelo Tosatti <mtosa...@redhat.com> wrote:
>
>
> v2: condition enablement of new mapping to new machine types (Paolo)
> v3: fix changelog
>
> -----
>
>
> Align guest physical address and host physical address
> beyond guest 4GB on a 1GB boundary.
>
> Otherwise 1GB TLBs cannot be cached for the range.
>
> Signed-off-by: Marcelo Tosatti <mtosa...@redhat.com>
>
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index 0c313fe..534e067 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -1116,7 +1116,7 @@ FWCfgState *pc_memory_init(MemoryRegion *system_memory,
[...]
> + /*
> + *
> + * 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) {
'gb_align' is one shot usage, it would be better to just add it as an argument
to pc_memory_init(). That would allow to avoid extending PcGuestInfo needlessly,
since gb_align isn't reused.
> + unsigned long holesize = 0x100000000ULL - below_4g_mem_size;
> +
> + memory_region_init_alias(ram_above_4g, NULL, "ram-above-4g", ram,
> + 0x100000000ULL,
> + above_4g_mem_size - holesize);
> + memory_region_add_subregion(system_memory, 0x100000000ULL,
> ram_above_4g);
[...]
> diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
> index 6083839..00afe4a 100644
> --- a/include/hw/i386/pc.h
> +++ b/include/hw/i386/pc.h
> @@ -20,6 +20,7 @@ typedef struct PcPciInfo {
> struct PcGuestInfo {
> bool has_pci_info;
> bool isapc_ram_fw;
> + bool gb_align;
> FWCfgState *fw_cfg;
> };
it doesn't apply anymore.
