Commit 011901fc authored by Christoph Schlameuss's avatar Christoph Schlameuss Committed by Janosch Frank
Browse files

selftests: kvm: s390: Add s390x ucontrol test suite with hpage test 



Add test suite to validate the s390x architecture specific ucontrol KVM
interface.

Make use of the selftest test harness.

* uc_cap_hpage testcase verifies that a ucontrol VM cannot be run with
  hugepages.

To allow testing of the ucontrol interface the kernel needs a
non-default config containing CONFIG_KVM_S390_UCONTROL.
This config needs to be set to built-in (y) as this cannot be built as
module.

Signed-off-by: default avatarChristoph Schlameuss <schlameuss@linux.ibm.com>
Reviewed-by: default avatarJanosch Frank <frankja@linux.ibm.com>
Link: https://lore.kernel.org/r/20240807154512.316936-4-schlameuss@linux.ibm.com


Signed-off-by: default avatarJanosch Frank <frankja@linux.ibm.com>
Message-ID: <20240807154512.316936-4-schlameuss@linux.ibm.com>
parent 84548218

tools/testing/selftests/kvm/.gitignore

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@@ -5,3 +5,4 @@ 
!*.h

!*.S

!*.sh

!config

tools/testing/selftests/kvm/Makefile

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@@ -186,6 +186,7 @@ TEST_GEN_PROGS_s390x += s390x/tprot 
TEST_GEN_PROGS_s390x += s390x/cmma_test

TEST_GEN_PROGS_s390x += s390x/debug_test

TEST_GEN_PROGS_s390x += s390x/shared_zeropage_test

TEST_GEN_PROGS_s390x += s390x/ucontrol_test

TEST_GEN_PROGS_s390x += demand_paging_test

TEST_GEN_PROGS_s390x += dirty_log_test

TEST_GEN_PROGS_s390x += guest_print_test

tools/testing/selftests/kvm/s390x/config

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CONFIG_KVM=y

CONFIG_KVM_S390_UCONTROL=y

tools/testing/selftests/kvm/s390x/ucontrol_test.c

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// SPDX-License-Identifier: GPL-2.0-only

/*

 * Test code for the s390x kvm ucontrol interface

 *

 * Copyright IBM Corp. 2024

 *

 * Authors:

 *  Christoph Schlameuss <schlameuss@linux.ibm.com>

 */

#include "kselftest_harness.h"

#include "kvm_util.h"



#include <linux/capability.h>

#include <linux/sizes.h>



/* so directly declare capget to check caps without libcap */

int capget(cap_user_header_t header, cap_user_data_t data);



/**

 * In order to create user controlled virtual machines on S390,

 * check KVM_CAP_S390_UCONTROL and use the flag KVM_VM_S390_UCONTROL

 * as privileged user (SYS_ADMIN).

 */

void require_ucontrol_admin(void)

{

	struct __user_cap_data_struct data[_LINUX_CAPABILITY_U32S_3];

	struct __user_cap_header_struct hdr = {

		.version = _LINUX_CAPABILITY_VERSION_3,

	};

	int rc;



	rc = capget(&hdr, data);

	TEST_ASSERT_EQ(0, rc);

	TEST_REQUIRE((data->effective & CAP_TO_MASK(CAP_SYS_ADMIN)) > 0);



	TEST_REQUIRE(kvm_has_cap(KVM_CAP_S390_UCONTROL));

}



/**

 * Assert HPAGE CAP cannot be enabled on UCONTROL VM

 */

TEST(uc_cap_hpage)

{

	int rc, kvm_fd, vm_fd, vcpu_fd;

	struct kvm_enable_cap cap = {

		.cap = KVM_CAP_S390_HPAGE_1M,

	};



	require_ucontrol_admin();



	kvm_fd = open_kvm_dev_path_or_exit();

	vm_fd = ioctl(kvm_fd, KVM_CREATE_VM, KVM_VM_S390_UCONTROL);

	ASSERT_GE(vm_fd, 0);



	/* assert hpages are not supported on ucontrol vm */

	rc = ioctl(vm_fd, KVM_CHECK_EXTENSION, KVM_CAP_S390_HPAGE_1M);

	EXPECT_EQ(0, rc);



	/* Test that KVM_CAP_S390_HPAGE_1M can't be enabled for a ucontrol vm */

	rc = ioctl(vm_fd, KVM_ENABLE_CAP, cap);

	EXPECT_EQ(-1, rc);

	EXPECT_EQ(EINVAL, errno);



	/* assert HPAGE CAP is rejected after vCPU creation */

	vcpu_fd = ioctl(vm_fd, KVM_CREATE_VCPU, 0);

	ASSERT_GE(vcpu_fd, 0);

	rc = ioctl(vm_fd, KVM_ENABLE_CAP, cap);

	EXPECT_EQ(-1, rc);

	EXPECT_EQ(EBUSY, errno);



	close(vcpu_fd);

	close(vm_fd);

	close(kvm_fd);

}



TEST_HARNESS_MAIN