KVM on S390x requires the virtual address space of the guest's RAM to be within the first 256GB.
The general direction I'd like to see KVM on S390 move is that this requirement is losened, but for now that's what we're stuck with. So let's just hack up qemu_ram_alloc until KVM behaves nicely :-). Signed-off-by: Alexander Graf <ag...@suse.de> --- v5 -> v6: - correct typo --- exec.c | 6 ++++++ 1 files changed, 6 insertions(+), 0 deletions(-) diff --git a/exec.c b/exec.c index eb1ee51..7b7fb5b 100644 --- a/exec.c +++ b/exec.c @@ -2411,7 +2411,13 @@ ram_addr_t qemu_ram_alloc(ram_addr_t size) size = TARGET_PAGE_ALIGN(size); new_block = qemu_malloc(sizeof(*new_block)); +#if defined(TARGET_S390X) && defined(CONFIG_KVM) + /* XXX S390 KVM requires the topmost vma of the RAM to be < 256GB */ + new_block->host = mmap((void*)0x1000000, size, PROT_EXEC|PROT_READ|PROT_WRITE, + MAP_SHARED | MAP_ANONYMOUS, -1, 0); +#else new_block->host = qemu_vmalloc(size); +#endif #ifdef MADV_MERGEABLE madvise(new_block->host, size, MADV_MERGEABLE); #endif -- 1.6.0.2