On 2011-09-05 10:07, Avi Kivity wrote:
> To make good use of transparent hugepages, KVM requires that guest-physical
> and host-virtual addresses share the low 21 bits (as opposed to just the low
> 12 bits normally required).
>
> Adjust qemu_vmalloc() to honor that requirement. Ignore it for small regions
> to avoid fragmentation.
>
> Signed-off-by: Avi Kivity<address@hidden>
> ---
> oslib-posix.c | 14 +++++++++++++-
> 1 files changed, 13 insertions(+), 1 deletions(-)
>
> diff --git a/oslib-posix.c b/oslib-posix.c
> index 196099c..a304fb0 100644
> --- a/oslib-posix.c
> +++ b/oslib-posix.c
> @@ -35,6 +35,13 @@
> extern int daemon(int, int);
> #endif
>
> +#if defined(__linux__)&& defined(__x86_64__)
> + /* Use 2MB alignment so transparent hugepages can be used by KVM */
Aren't transparent hugepages also available in TCG mode? Then just
remove "by KVM" from subject and comment.