On 3/27/24 10:42 AM, Manali Shukla wrote:
> By default, HLT instruction executed by guest is intercepted by hypervisor.
> However, KVM_CAP_X86_DISABLE_EXITS capability can be used to not intercept
> HLT by setting KVM_X86_DISABLE_EXITS_HLT.
>
> Add a test case to test KVM_X86_DISABLE_EXITS_HLT functionality.
>
> Suggested-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> Signed-off-by: Manali Shukla <manali.shukla@xxxxxxx>
Thank you for the new test patch. We have been trying to ensure TAP
conformance for tests which cannot be achieved if new tests aren't using
TAP already. Please make your test TAP compliant.
> ---
> tools/testing/selftests/kvm/Makefile | 1 +
> .../kvm/x86_64/halt_disable_exit_test.c | 113 ++++++++++++++++++
Add generated object to .gitignore file.
> 2 files changed, 114 insertions(+)
> create mode 100644 tools/testing/selftests/kvm/x86_64/halt_disable_exit_test.c
>
> diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
> index c75251d5c97c..9f72abb95d2e 100644
> --- a/tools/testing/selftests/kvm/Makefile
> +++ b/tools/testing/selftests/kvm/Makefile
> @@ -89,6 +89,7 @@ TEST_GEN_PROGS_x86_64 += x86_64/set_sregs_test
> TEST_GEN_PROGS_x86_64 += x86_64/smaller_maxphyaddr_emulation_test
> TEST_GEN_PROGS_x86_64 += x86_64/smm_test
> TEST_GEN_PROGS_x86_64 += x86_64/state_test
> +TEST_GEN_PROGS_x86_64 += x86_64/halt_disable_exit_test
> TEST_GEN_PROGS_x86_64 += x86_64/vmx_preemption_timer_test
> TEST_GEN_PROGS_x86_64 += x86_64/svm_vmcall_test
> TEST_GEN_PROGS_x86_64 += x86_64/svm_int_ctl_test
> diff --git a/tools/testing/selftests/kvm/x86_64/halt_disable_exit_test.c b/tools/testing/selftests/kvm/x86_64/halt_disable_exit_test.c
> new file mode 100644
> index 000000000000..b7279dd0eaff
> --- /dev/null
> +++ b/tools/testing/selftests/kvm/x86_64/halt_disable_exit_test.c
> @@ -0,0 +1,113 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * KVM disable halt exit test
> + *
> + * Copyright (C) 2024 Advanced Micro Devices, Inc.
> + */
> +#include <pthread.h>
> +#include <signal.h>
> +#include "kvm_util.h"
> +#include "svm_util.h"
> +#include "processor.h"
> +#include "test_util.h"
> +
> +pthread_t task_thread, vcpu_thread;
> +#define SIG_IPI SIGUSR1
> +
> +static void guest_code(uint8_t is_hlt_exec)
> +{
> + while (!READ_ONCE(is_hlt_exec))
> + ;
> +
> + safe_halt();
> + GUEST_DONE();
> +}
> +
> +static void *task_worker(void *arg)
> +{
> + uint8_t *is_hlt_exec = (uint8_t *)arg;
> +
> + usleep(1000);
> + WRITE_ONCE(*is_hlt_exec, 1);
> + pthread_kill(vcpu_thread, SIG_IPI);
> + return 0;
> +}
> +
> +static void *vcpu_worker(void *arg)
> +{
> + int ret;
> + int sig = -1;
> + uint8_t *is_hlt_exec = (uint8_t *)arg;
> + struct kvm_vm *vm;
> + struct kvm_run *run;
> + struct kvm_vcpu *vcpu;
> + struct kvm_signal_mask *sigmask = alloca(offsetof(struct kvm_signal_mask, sigset)
> + + sizeof(sigset_t));
> + sigset_t *sigset = (sigset_t *) &sigmask->sigset;
> +
> + /* Create a VM without in kernel APIC support */
> + vm = __vm_create(VM_SHAPE_DEFAULT, 1, 0, false);
> + vm_enable_cap(vm, KVM_CAP_X86_DISABLE_EXITS, KVM_X86_DISABLE_EXITS_HLT);
> + vcpu = vm_vcpu_add(vm, 0, guest_code);
> + vcpu_args_set(vcpu, 1, *is_hlt_exec);
> +
> + /*
> + * SIG_IPI is unblocked atomically while in KVM_RUN. It causes the
> + * ioctl to return with -EINTR, but it is still pending and we need
> + * to accept it with the sigwait.
> + */
> + sigmask->len = 8;
> + pthread_sigmask(0, NULL, sigset);
> + sigdelset(sigset, SIG_IPI);
> + vcpu_ioctl(vcpu, KVM_SET_SIGNAL_MASK, sigmask);
> + sigemptyset(sigset);
> + sigaddset(sigset, SIG_IPI);
> + run = vcpu->run;
> +
> +again:
> + ret = __vcpu_run(vcpu);
> + TEST_ASSERT_EQ(errno, EINTR);
> +
> + if (ret == -1 && errno == EINTR) {
> + sigwait(sigset, &sig);
> + assert(sig == SIG_IPI);
> + TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_INTR);
> + goto again;
> + }
> +
> + if (run->exit_reason == KVM_EXIT_HLT)
> + TEST_FAIL("Expected KVM_EXIT_INTR, got KVM_EXIT_HLT");
> +
> + TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);
> + kvm_vm_free(vm);
> + return 0;
> +}
> +
> +int main(int argc, char *argv[])
> +{
> + int ret;
> + void *retval;
> + uint8_t is_halt_exec;
> + sigset_t sigset;
> +
> + TEST_REQUIRE(kvm_has_cap(KVM_CAP_X86_DISABLE_EXITS));
> +
> + /* Ensure that vCPU threads start with SIG_IPI blocked. */
> + sigemptyset(&sigset);
> + sigaddset(&sigset, SIG_IPI);
> + pthread_sigmask(SIG_BLOCK, &sigset, NULL);
> +
> + ret = pthread_create(&vcpu_thread, NULL, vcpu_worker, &is_halt_exec);
> + TEST_ASSERT(ret == 0, "pthread_create vcpu thread failed errno=%d", errno);
> +
> + ret = pthread_create(&task_thread, NULL, task_worker, &is_halt_exec);
> + TEST_ASSERT(ret == 0, "pthread_create task thread failed errno=%d", errno);
> +
> + pthread_join(vcpu_thread, &retval);
> + TEST_ASSERT(ret == 0, "pthread_join on vcpu thread failed with errno=%d", ret);
> +
> + pthread_join(task_thread, &retval);
> + TEST_ASSERT(ret == 0, "pthread_join on task thread failed with errno=%d", ret);
> +
> + return 0;
> +}
--
BR,
Muhammad Usama Anjum
