At present, an explicit test disallows use of -mem-path when kvm is enabled but KVM_CAP_SYNC_MMU is not set. In particular, this prevents the user from using hugetlbfs to back the guest memory.
I can see no reason for this check, and when I asked about it previously, the only theory offered was that this was a limitation of the very early days of kvm which only happened to match the SYNC_MMU flag by accident. This patch, therefore, removes the check. This is of particular use to us on POWER, where we haven't yet implement SYNC_MMU, but where backing the guest with hugepages is possible, and in fact mandatory (for now). Signed-off-by: David Gibson <da...@gibson.dropbear.id.au> --- exec.c | 5 ----- 1 files changed, 0 insertions(+), 5 deletions(-) diff --git a/exec.c b/exec.c index 476b507..041637c 100644 --- a/exec.c +++ b/exec.c @@ -2818,11 +2818,6 @@ static void *file_ram_alloc(RAMBlock *block, return NULL; } - if (kvm_enabled() && !kvm_has_sync_mmu()) { - fprintf(stderr, "host lacks kvm mmu notifiers, -mem-path unsupported\n"); - return NULL; - } - if (asprintf(&filename, "%s/qemu_back_mem.XXXXXX", path) == -1) { return NULL; } -- 1.7.5.4