When running QEMU with KVM under z/VM, the memory for the guest
is allocated via legacy_s390_alloc() since the KVM_CAP_S390_COW
extension is not supported on z/VM. legacy_s390_alloc() then uses
mmap(... PROT_EXEC ...) for the guest memory - but this does not
work when running with SELinux enabled, mmap() fails and QEMU aborts
with the following error message:
cannot set up guest memory 's390.ram': Permission denied
Looking at the other allocator function qemu_anon_ram_alloc(), it
seems like PROT_EXEC is normally not needed for allocating the
guest RAM, and indeed, the guest also starts successfully under
z/VM when we remove the PROT_EXEC from the legacy_s390_alloc()
function. So let's get rid of that flag here to be able to run
with SELinux under z/VM, too.
Signed-off-by: Thomas Huth <th...@redhat.com>
---
target/s390x/kvm.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
index ac47154..5167436 100644
--- a/target/s390x/kvm.c
+++ b/target/s390x/kvm.c
@@ -678,8 +678,7 @@ static void *legacy_s390_alloc(size_t size, uint64_t *align)
{
void *mem;
- mem = mmap((void *) 0x800000000ULL, size,
- PROT_EXEC|PROT_READ|PROT_WRITE,
+ mem = mmap((void *) 0x800000000ULL, size, PROT_READ | PROT_WRITE,
MAP_SHARED | MAP_ANONYMOUS | MAP_FIXED, -1, 0);
return mem == MAP_FAILED ? NULL : mem;
}
--
1.8.3.1
