Commit 6b02494d authored by Alexander Graf's avatar Alexander Graf Committed by Aurelien Jarno
Browse files

Allocate physical memory in low virtual address space 



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: default avatarAlexander Graf <agraf@suse.de>
Signed-off-by: default avatarAurelien Jarno <aurelien@aurel32.net>
parent 0e60a699

exec.c

+6 −0
Original line number Diff line number Diff line
@@ -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