From c68c21ca929771a1f128d886359f9229d31cf80c Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Thu, 11 Apr 2019 15:57:14 +0200 Subject: [PATCH] selftests: kvm/evmcs_test: complete I/O before migrating guest state Starting state migration after an IO exit without first completing IO may result in test failures. We already have two tests that need this (this patch in fact fixes evmcs_test, similar to what was fixed for state_test in commit 0f73bbc851ed, "KVM: selftests: complete IO before migrating guest state", 2019-03-13) and a third is coming. So, move the code to vcpu_save_state, and while at it do not access register state until after I/O is complete. Signed-off-by: Paolo Bonzini --- tools/testing/selftests/kvm/lib/kvm_util.c | 5 +++++ .../testing/selftests/kvm/lib/x86_64/processor.c | 8 ++++++++ tools/testing/selftests/kvm/x86_64/evmcs_test.c | 5 +++-- tools/testing/selftests/kvm/x86_64/state_test.c | 15 +-------------- 4 files changed, 17 insertions(+), 16 deletions(-) diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c index efa0aad8b3c69..4ca96b228e46b 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -91,6 +91,11 @@ static void vm_open(struct kvm_vm *vm, int perm, unsigned long type) if (vm->kvm_fd < 0) exit(KSFT_SKIP); + if (!kvm_check_cap(KVM_CAP_IMMEDIATE_EXIT)) { + fprintf(stderr, "immediate_exit not available, skipping test\n"); + exit(KSFT_SKIP); + } + vm->fd = ioctl(vm->kvm_fd, KVM_CREATE_VM, type); TEST_ASSERT(vm->fd >= 0, "KVM_CREATE_VM ioctl failed, " "rc: %i errno: %i", vm->fd, errno); diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c index f28127f4a3af6..b363c9611bd64 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/processor.c +++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c @@ -1030,6 +1030,14 @@ struct kvm_x86_state *vcpu_save_state(struct kvm_vm *vm, uint32_t vcpuid) nested_size, sizeof(state->nested_)); } + /* + * When KVM exits to userspace with KVM_EXIT_IO, KVM guarantees + * guest state is consistent only after userspace re-enters the + * kernel with KVM_RUN. Complete IO prior to migrating state + * to a new VM. + */ + vcpu_run_complete_io(vm, vcpuid); + nmsrs = kvm_get_num_msrs(vm); list = malloc(sizeof(*list) + nmsrs * sizeof(list->indices[0])); list->nmsrs = nmsrs; diff --git a/tools/testing/selftests/kvm/x86_64/evmcs_test.c b/tools/testing/selftests/kvm/x86_64/evmcs_test.c index c49c2a28b0eb2..36669684eca58 100644 --- a/tools/testing/selftests/kvm/x86_64/evmcs_test.c +++ b/tools/testing/selftests/kvm/x86_64/evmcs_test.c @@ -123,8 +123,6 @@ int main(int argc, char *argv[]) stage, run->exit_reason, exit_reason_str(run->exit_reason)); - memset(®s1, 0, sizeof(regs1)); - vcpu_regs_get(vm, VCPU_ID, ®s1); switch (get_ucall(vm, VCPU_ID, &uc)) { case UCALL_ABORT: TEST_ASSERT(false, "%s at %s:%d", (const char *)uc.args[0], @@ -144,6 +142,9 @@ int main(int argc, char *argv[]) stage, (ulong)uc.args[1]); state = vcpu_save_state(vm, VCPU_ID); + memset(®s1, 0, sizeof(regs1)); + vcpu_regs_get(vm, VCPU_ID, ®s1); + kvm_vm_release(vm); /* Restore state in a new VM. */ diff --git a/tools/testing/selftests/kvm/x86_64/state_test.c b/tools/testing/selftests/kvm/x86_64/state_test.c index 30f75856cf398..e0a3c0204b7cd 100644 --- a/tools/testing/selftests/kvm/x86_64/state_test.c +++ b/tools/testing/selftests/kvm/x86_64/state_test.c @@ -134,11 +134,6 @@ int main(int argc, char *argv[]) struct kvm_cpuid_entry2 *entry = kvm_get_supported_cpuid_entry(1); - if (!kvm_check_cap(KVM_CAP_IMMEDIATE_EXIT)) { - fprintf(stderr, "immediate_exit not available, skipping test\n"); - exit(KSFT_SKIP); - } - /* Create VM */ vm = vm_create_default(VCPU_ID, 0, guest_code); vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid()); @@ -179,18 +174,10 @@ int main(int argc, char *argv[]) uc.args[1] == stage, "Unexpected register values vmexit #%lx, got %lx", stage, (ulong)uc.args[1]); - /* - * When KVM exits to userspace with KVM_EXIT_IO, KVM guarantees - * guest state is consistent only after userspace re-enters the - * kernel with KVM_RUN. Complete IO prior to migrating state - * to a new VM. - */ - vcpu_run_complete_io(vm, VCPU_ID); - + state = vcpu_save_state(vm, VCPU_ID); memset(®s1, 0, sizeof(regs1)); vcpu_regs_get(vm, VCPU_ID, ®s1); - state = vcpu_save_state(vm, VCPU_ID); kvm_vm_release(vm); /* Restore state in a new VM. */