On Thu, Aug 25, 2022 at 11:25:18PM +0000, Sean Christopherson wrote: > Do init_ucall() automatically during VM creation to kill two (three?) > birds with one stone. > > First, initializing ucall immediately after VM creations allows forcing > aarch64's MMIO ucall address to immediately follow memslot0. This is > still somewhat fragile as tests could clobber the MMIO address with a > new memslot, but it's safe-ish since tests have to be conversative when > accounting for memslot0. And this can be hardened in the future by > creating a read-only memslot for the MMIO page (KVM ARM exits with MMIO > if the guest writes to a read-only memslot). Add a TODO to document that > selftests can and should use a memslot for the ucall MMIO (doing so > requires yet more rework because tests assumes thay can use all memslots > except memslot0). > > Second, initializing ucall for all VMs prepares for making ucall > initialization meaningful on all architectures. aarch64 is currently the > only arch that needs to do any setup, but that will change in the future > by switching to a pool-based implementation (instead of the current > stack-based approach). > > Lastly, defining the ucall MMIO address from common code will simplify > switching all architectures (except s390) to a common MMIO-based ucall > implementation (if there's ever sufficient motivation to do so). > > Cc: Oliver Upton <oliver.upton@xxxxxxxxx> > Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx> > --- > .../selftests/kvm/aarch64/arch_timer.c | 1 - > .../selftests/kvm/aarch64/debug-exceptions.c | 1 - > .../selftests/kvm/aarch64/hypercalls.c | 1 - > .../testing/selftests/kvm/aarch64/psci_test.c | 1 - > .../testing/selftests/kvm/aarch64/vgic_init.c | 2 - > .../testing/selftests/kvm/aarch64/vgic_irq.c | 1 - > tools/testing/selftests/kvm/dirty_log_test.c | 2 - > .../selftests/kvm/include/ucall_common.h | 6 +-- > .../selftests/kvm/kvm_page_table_test.c | 1 - > .../testing/selftests/kvm/lib/aarch64/ucall.c | 54 ++----------------- > tools/testing/selftests/kvm/lib/kvm_util.c | 11 ++++ > .../selftests/kvm/lib/perf_test_util.c | 2 - > tools/testing/selftests/kvm/lib/riscv/ucall.c | 2 +- > tools/testing/selftests/kvm/lib/s390x/ucall.c | 2 +- > .../testing/selftests/kvm/lib/x86_64/ucall.c | 2 +- > .../testing/selftests/kvm/memslot_perf_test.c | 1 - > tools/testing/selftests/kvm/rseq_test.c | 1 - > tools/testing/selftests/kvm/steal_time.c | 1 - > .../kvm/system_counter_offset_test.c | 1 - > 19 files changed, 20 insertions(+), 73 deletions(-) > Reviewed-by: Andrew Jones <andrew.jones@xxxxxxxxx> Thanks, drew
