On Wed, 2023-11-22 at 12:06 +0100, Thomas Huth wrote: > On 10/11/2023 14.52, Nico Boehr wrote: > > Until now, kvm-unit-tests has aligned guests to 1 MB in the host virtual > > address space. Unfortunately, some s390x environments require guests to > > be 2GB aligned in the host virtual address space, preventing > > kvm-unit-tests which act as a hypervisor from running there. > > > > We can't easily put guests at address 0, since we want to be able to run > > with MSO/MSL without having to maintain separate page tables for the > > guest physical memory. 2GB is also not a good choice, since the > > alloc_pages allocator will place its metadata there when the host has > > more than 2GB of memory. In addition, we also want a bit of space after > > the end of the host physical memory to be able to catch accesses beyond > > the end of physical memory. > > > > The vmalloc allocator unfortunately allocates memory starting at the > > highest virtual address which is not suitable for guest memory either > > due to additional constraints of some environments. > > > > The physical page allocator in memalign_pages() is also not a optimal > > choice, since every test running SIE would then require at least 4GB+1MB > > of physical memory. > > > > This results in a few quite complex allocation requirements, hence add a > > new function sie_guest_alloc() which allocates memory for a guest and > > then establishes a properly aligned virtual space mapping. > > > > Rework snippet test and sie tests to use the new sie_guest_alloc() > > function. > > > > Reviewed-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx> > > Link: https://lore.kernel.org/r/20231106170849.1184162-3-nrb@xxxxxxxxxxxxx > > Signed-off-by: Nico Boehr <nrb@xxxxxxxxxxxxx> > > --- > > lib/s390x/sie.h | 2 ++ > > lib/s390x/snippet.h | 9 +++------ > > lib/s390x/sie.c | 42 ++++++++++++++++++++++++++++++++++++++++++ > > s390x/sie.c | 4 ++-- > > 4 files changed, 49 insertions(+), 8 deletions(-) > > Hi Nico! > > a colleague of mine (Jan) told me today that the current SIE-related tests > of the kvm-unit-tests are failing when being run from a KVM guest (i.e. when > we're testing a double-nested scenario). I've bisected the problem and ended > up with this patch here. > Could you please check whether "./run_tests.sh sie mvpg-sie spec_ex-sie" > still works for you from within a KVM guest? If you're getting a validity intercept, this should be fixed by KVM: s390: vsie: fix wrong VIR 37 when MSO is used https://lore.kernel.org/kvm/20231102153549.53984-1-imbrenda@xxxxxxxxxxxxx/ > > Thanks, > Thomas > >
