Re: [PATCH 6/7] KVM: selftests: Automatically run xAPIC IPI migration test when possible

["Garg, Shivank" <shivankg@amd.com>]

On Wed, 2026-09-02 at 17:16 -0700, Sean Christopherson wrote:
> Rework the interface to the xAPIC IPI test to automatically run the
> migration testcase if at least two NUMA nodes are found.  The test exists
> specifically to validate KVM's handling of migration of the APIC backing
> page, i.e. forcing end users to opt-in to running the test in migration
> mode largely defeats the purpose of the test.
> 
> Run both the "sleeping" and "migration" testcases by default, e.g. so that
> the more basic testcase will fail if KVM completely breaks IPI delivery.
> 
> Keep the -m / migration parameter so that infrastructure that wants to
> specifically test the migration case can do so and not get false passes.
> 
> Signed-off-by: Sean Christopherson <seanjc@google.com>
> ---
>  .../selftests/kvm/x86/xapic_ipi_test.c        | 40 +++++++++++++------
>  1 file changed, 27 insertions(+), 13 deletions(-)
> 
> diff --git a/tools/testing/selftests/kvm/x86/xapic_ipi_test.c b/tools/testing/selftests/kvm/x86/xapic_ipi_test.c
> index 42c601617f5a..c5b506eb5e7f 100644
> --- a/tools/testing/selftests/kvm/x86/xapic_ipi_test.c
> +++ b/tools/testing/selftests/kvm/x86/xapic_ipi_test.c
> @@ -245,14 +245,13 @@ void do_migrations(struct test_data_page *data, int run_secs, int delay_usecs,
>  		delay_usecs);
>  
>  	nodes = kvm_get_numa_memory_nodes(&nodemask);
> +	TEST_ASSERT(nodes > 1,
> +		    "NUMA nodes disappeared?  nodemask = 0x%lx", nodemask);
>  
>  	fprintf(stderr, "Numa nodes found amongst first %lu possible nodes "
>  		"(each 1-bit indicates node is present): %#lx\n",
>  		BITS_PER_TYPE(nodemask), nodemask);
>  
> -	TEST_ASSERT(nodes > 1,
> -		    "Did not find at least 2 numa nodes. Can't do migration");
> -
>  	fprintf(stderr, "Migrating amongst %d nodes found\n", nodes);
>  
>  	from = kvm_get_next_numa_node(nodemask, -1);
> @@ -351,26 +350,17 @@ void get_cmdline_args(int argc, char *argv[], int *run_secs,
>  	}
>  }
>  
> -int main(int argc, char *argv[])
> +static void test_xapic_ipi(int run_secs, int delay_usecs, bool migrate)
>  {
>  	int wait_secs;
>  	const int max_halter_wait = 10;
> -	int run_secs = 0;
> -	int delay_usecs = 0;
>  	struct test_data_page *data;
>  	gva_t test_data_page_gva;
> -	bool migrate = false;
>  	pthread_t threads[2];
>  	struct thread_params params[2];
>  	struct kvm_vm *vm;
>  	u64 *pipis_rcvd;
>  
> -	get_cmdline_args(argc, argv, &run_secs, &migrate, &delay_usecs);
> -	if (run_secs <= 0)
> -		run_secs = DEFAULT_RUN_SECS;
> -	if (delay_usecs <= 0)
> -		delay_usecs = DEFAULT_DELAY_USECS;
> -
>  	vm = vm_create_with_one_vcpu(&params[0].vcpu, halter_guest_code);
>  
>  	vm_install_exception_handler(vm, IPI_VECTOR, guest_ipi_handler);
> @@ -458,5 +448,29 @@ int main(int argc, char *argv[])
>  
>  	kvm_vm_free(vm);
>  
> +}
> +
> +int main(int argc, char *argv[])
> +{
> +	bool force_migrate = false;
> +	unsigned long nodemask;
> +	int run_secs = 0;
> +	int delay_usecs = 0;
> +
> +	get_cmdline_args(argc, argv, &run_secs, &force_migrate, &delay_usecs);
> +	if (run_secs <= 0)
> +		run_secs = DEFAULT_RUN_SECS;
> +	if (delay_usecs <= 0)
> +		delay_usecs = DEFAULT_DELAY_USECS;
> +
> +	if (!force_migrate)
> +		test_xapic_ipi(run_secs, delay_usecs, false);
> +
> +	if (kvm_get_numa_memory_nodes(&nodemask) > 1)
> +		test_xapic_ipi(run_secs, delay_usecs, true);
> +	else
> +		TEST_ASSERT(!force_migrate,
> +			    "Did not find at least 2 numa nodes. Can't do migration");
> +
>  	return 0;
>  }


Reviewed-by: Shivank Garg <shivankg@amd.com>

Thanks,
Shivank