From 4689752c79fa30e91b49b39a9fba93c4d1f3e20c Mon Sep 17 00:00:00 2001 From: Steffen Eiden Date: Mon, 16 May 2022 11:33:35 +0000 Subject: [PATCH 1/4] drivers/s390/char: Add Ultravisor io device This patch adds a new miscdevice to expose some Ultravisor functions to userspace. Userspace can send IOCTLs to the uvdevice that will then emit a corresponding Ultravisor Call and hands the result over to userspace. The uvdevice is available if the Ultravisor Call facility is present. Userspace can call the Retrieve Attestation Measurement Ultravisor Call using IOCTLs on the uvdevice. The uvdevice will do some sanity checks first. Then, copy the request data to kernel space, build the UVCB, perform the UV call, and copy the result back to userspace. Signed-off-by: Steffen Eiden Reviewed-by: Janosch Frank Reviewed-by: Claudio Imbrenda Link: https://lore.kernel.org/kvm/20220516113335.338212-1-seiden@linux.ibm.com/ Message-Id: <20220516113335.338212-1-seiden@linux.ibm.com> Signed-off-by: Janosch Frank (whitespace and tristate fixes, pick) --- MAINTAINERS | 2 + arch/s390/include/asm/uv.h | 23 ++- arch/s390/include/uapi/asm/uvdevice.h | 51 +++++ drivers/s390/char/Kconfig | 10 + drivers/s390/char/Makefile | 1 + drivers/s390/char/uvdevice.c | 257 ++++++++++++++++++++++++++ 6 files changed, 343 insertions(+), 1 deletion(-) create mode 100644 arch/s390/include/uapi/asm/uvdevice.h create mode 100644 drivers/s390/char/uvdevice.c diff --git a/MAINTAINERS b/MAINTAINERS index 61d9f114c37f..a74488b7bb7c 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -10779,9 +10779,11 @@ F: Documentation/virt/kvm/s390* F: arch/s390/include/asm/gmap.h F: arch/s390/include/asm/kvm* F: arch/s390/include/uapi/asm/kvm* +F: arch/s390/include/uapi/asm/uvdevice.h F: arch/s390/kernel/uv.c F: arch/s390/kvm/ F: arch/s390/mm/gmap.c +F: drivers/s390/char/uvdevice.c F: tools/testing/selftests/kvm/*/s390x/ F: tools/testing/selftests/kvm/s390x/ diff --git a/arch/s390/include/asm/uv.h b/arch/s390/include/asm/uv.h index a2d376b8bce3..cfea7b77a5b8 100644 --- a/arch/s390/include/asm/uv.h +++ b/arch/s390/include/asm/uv.h @@ -2,7 +2,7 @@ /* * Ultravisor Interfaces * - * Copyright IBM Corp. 2019 + * Copyright IBM Corp. 2019, 2022 * * Author(s): * Vasily Gorbik @@ -52,6 +52,7 @@ #define UVC_CMD_UNPIN_PAGE_SHARED 0x0342 #define UVC_CMD_SET_SHARED_ACCESS 0x1000 #define UVC_CMD_REMOVE_SHARED_ACCESS 0x1001 +#define UVC_CMD_RETR_ATTEST 0x1020 /* Bits in installed uv calls */ enum uv_cmds_inst { @@ -76,6 +77,7 @@ enum uv_cmds_inst { BIT_UVC_CMD_UNSHARE_ALL = 20, BIT_UVC_CMD_PIN_PAGE_SHARED = 21, BIT_UVC_CMD_UNPIN_PAGE_SHARED = 22, + BIT_UVC_CMD_RETR_ATTEST = 28, }; enum uv_feat_ind { @@ -219,6 +221,25 @@ struct uv_cb_share { u64 reserved28; } __packed __aligned(8); +/* Retrieve Attestation Measurement */ +struct uv_cb_attest { + struct uv_cb_header header; /* 0x0000 */ + u64 reserved08[2]; /* 0x0008 */ + u64 arcb_addr; /* 0x0018 */ + u64 cont_token; /* 0x0020 */ + u8 reserved28[6]; /* 0x0028 */ + u16 user_data_len; /* 0x002e */ + u8 user_data[256]; /* 0x0030 */ + u32 reserved130[3]; /* 0x0130 */ + u32 meas_len; /* 0x013c */ + u64 meas_addr; /* 0x0140 */ + u8 config_uid[16]; /* 0x0148 */ + u32 reserved158; /* 0x0158 */ + u32 add_data_len; /* 0x015c */ + u64 add_data_addr; /* 0x0160 */ + u64 reserved168[4]; /* 0x0168 */ +} __packed __aligned(8); + static inline int __uv_call(unsigned long r1, unsigned long r2) { int cc; diff --git a/arch/s390/include/uapi/asm/uvdevice.h b/arch/s390/include/uapi/asm/uvdevice.h new file mode 100644 index 000000000000..10a5ac918e02 --- /dev/null +++ b/arch/s390/include/uapi/asm/uvdevice.h @@ -0,0 +1,51 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +/* + * Copyright IBM Corp. 2022 + * Author(s): Steffen Eiden + */ +#ifndef __S390_ASM_UVDEVICE_H +#define __S390_ASM_UVDEVICE_H + +#include + +struct uvio_ioctl_cb { + __u32 flags; + __u16 uv_rc; /* UV header rc value */ + __u16 uv_rrc; /* UV header rrc value */ + __u64 argument_addr; /* Userspace address of uvio argument */ + __u32 argument_len; + __u8 reserved14[0x40 - 0x14]; /* must be zero */ +}; + +#define UVIO_ATT_USER_DATA_LEN 0x100 +#define UVIO_ATT_UID_LEN 0x10 +struct uvio_attest { + __u64 arcb_addr; /* 0x0000 */ + __u64 meas_addr; /* 0x0008 */ + __u64 add_data_addr; /* 0x0010 */ + __u8 user_data[UVIO_ATT_USER_DATA_LEN]; /* 0x0018 */ + __u8 config_uid[UVIO_ATT_UID_LEN]; /* 0x0118 */ + __u32 arcb_len; /* 0x0128 */ + __u32 meas_len; /* 0x012c */ + __u32 add_data_len; /* 0x0130 */ + __u16 user_data_len; /* 0x0134 */ + __u16 reserved136; /* 0x0136 */ +}; + +/* + * The following max values define an upper length for the IOCTL in/out buffers. + * However, they do not represent the maximum the Ultravisor allows which is + * often way smaller. By allowing larger buffer sizes we hopefully do not need + * to update the code with every machine update. It is therefore possible for + * userspace to request more memory than actually used by kernel/UV. + */ +#define UVIO_ATT_ARCB_MAX_LEN 0x100000 +#define UVIO_ATT_MEASUREMENT_MAX_LEN 0x8000 +#define UVIO_ATT_ADDITIONAL_MAX_LEN 0x8000 + +#define UVIO_DEVICE_NAME "uv" +#define UVIO_TYPE_UVC 'u' + +#define UVIO_IOCTL_ATT _IOWR(UVIO_TYPE_UVC, 0x01, struct uvio_ioctl_cb) + +#endif /* __S390_ASM_UVDEVICE_H */ diff --git a/drivers/s390/char/Kconfig b/drivers/s390/char/Kconfig index 6cc4b19acf85..ef8f41833c1a 100644 --- a/drivers/s390/char/Kconfig +++ b/drivers/s390/char/Kconfig @@ -100,6 +100,16 @@ config SCLP_OFB This option enables the Open-for-Business interface to the s390 Service Element. +config S390_UV_UAPI + def_tristate m + prompt "Ultravisor userspace API" + help + Selecting exposes parts of the UV interface to userspace + by providing a misc character device at /dev/uv. + Using IOCTLs one can interact with the UV. + The device is only available if the Ultravisor + Facility (158) is present. + config S390_TAPE def_tristate m prompt "S/390 tape device support" diff --git a/drivers/s390/char/Makefile b/drivers/s390/char/Makefile index c6fdb81a068a..ce32270082f5 100644 --- a/drivers/s390/char/Makefile +++ b/drivers/s390/char/Makefile @@ -48,6 +48,7 @@ obj-$(CONFIG_MONREADER) += monreader.o obj-$(CONFIG_MONWRITER) += monwriter.o obj-$(CONFIG_S390_VMUR) += vmur.o obj-$(CONFIG_CRASH_DUMP) += sclp_sdias.o zcore.o +obj-$(CONFIG_S390_UV_UAPI) += uvdevice.o hmcdrv-objs := hmcdrv_mod.o hmcdrv_dev.o hmcdrv_ftp.o hmcdrv_cache.o diag_ftp.o sclp_ftp.o obj-$(CONFIG_HMC_DRV) += hmcdrv.o diff --git a/drivers/s390/char/uvdevice.c b/drivers/s390/char/uvdevice.c new file mode 100644 index 000000000000..66505d7166a6 --- /dev/null +++ b/drivers/s390/char/uvdevice.c @@ -0,0 +1,257 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright IBM Corp. 2022 + * Author(s): Steffen Eiden + * + * This file provides a Linux misc device to give userspace access to some + * Ultravisor (UV) functions. The device only accepts IOCTLs and will only + * be present if the Ultravisor facility (158) is present. + * + * When userspace sends a valid IOCTL uvdevice will copy the input data to + * kernel space, do some basic validity checks to avoid kernel/system + * corruption. Any other check that the Ultravisor does will not be done by + * the uvdevice to keep changes minimal when adding new functionalities + * to existing UV-calls. + * After the checks uvdevice builds a corresponding + * Ultravisor Call Control Block, and sends the request to the Ultravisor. + * Then, it copies the response, including the return codes, back to userspace. + * It is the responsibility of the userspace to check for any error issued + * by UV and to interpret the UV response. The uvdevice acts as a communication + * channel for userspace to the Ultravisor. + */ + +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +static int uvio_build_uvcb_attest(struct uv_cb_attest *uvcb_attest, u8 *arcb, + u8 *meas, u8 *add_data, struct uvio_attest *uvio_attest) +{ + void __user *user_buf_arcb = (void __user *)uvio_attest->arcb_addr; + + if (copy_from_user(arcb, user_buf_arcb, uvio_attest->arcb_len)) + return -EFAULT; + + uvcb_attest->header.len = sizeof(*uvcb_attest); + uvcb_attest->header.cmd = UVC_CMD_RETR_ATTEST; + uvcb_attest->arcb_addr = (u64)arcb; + uvcb_attest->cont_token = 0; + uvcb_attest->user_data_len = uvio_attest->user_data_len; + memcpy(uvcb_attest->user_data, uvio_attest->user_data, sizeof(uvcb_attest->user_data)); + uvcb_attest->meas_len = uvio_attest->meas_len; + uvcb_attest->meas_addr = (u64)meas; + uvcb_attest->add_data_len = uvio_attest->add_data_len; + uvcb_attest->add_data_addr = (u64)add_data; + + return 0; +} + +static int uvio_copy_attest_result_to_user(struct uv_cb_attest *uvcb_attest, + struct uvio_ioctl_cb *uv_ioctl, + u8 *measurement, u8 *add_data, + struct uvio_attest *uvio_attest) +{ + struct uvio_attest __user *user_uvio_attest = (void __user *)uv_ioctl->argument_addr; + void __user *user_buf_add = (void __user *)uvio_attest->add_data_addr; + void __user *user_buf_meas = (void __user *)uvio_attest->meas_addr; + void __user *user_buf_uid = &user_uvio_attest->config_uid; + + if (copy_to_user(user_buf_meas, measurement, uvio_attest->meas_len)) + return -EFAULT; + if (add_data && copy_to_user(user_buf_add, add_data, uvio_attest->add_data_len)) + return -EFAULT; + if (copy_to_user(user_buf_uid, uvcb_attest->config_uid, sizeof(uvcb_attest->config_uid))) + return -EFAULT; + return 0; +} + +static int get_uvio_attest(struct uvio_ioctl_cb *uv_ioctl, struct uvio_attest *uvio_attest) +{ + u8 __user *user_arg_buf = (u8 __user *)uv_ioctl->argument_addr; + + if (copy_from_user(uvio_attest, user_arg_buf, sizeof(*uvio_attest))) + return -EFAULT; + + if (uvio_attest->arcb_len > UVIO_ATT_ARCB_MAX_LEN) + return -EINVAL; + if (uvio_attest->arcb_len == 0) + return -EINVAL; + if (uvio_attest->meas_len > UVIO_ATT_MEASUREMENT_MAX_LEN) + return -EINVAL; + if (uvio_attest->meas_len == 0) + return -EINVAL; + if (uvio_attest->add_data_len > UVIO_ATT_ADDITIONAL_MAX_LEN) + return -EINVAL; + if (uvio_attest->reserved136) + return -EINVAL; + return 0; +} + +/** + * uvio_attestation() - Perform a Retrieve Attestation Measurement UVC. + * + * @uv_ioctl: ioctl control block + * + * uvio_attestation() does a Retrieve Attestation Measurement Ultravisor Call. + * It verifies that the given userspace addresses are valid and request sizes + * are sane. Every other check is made by the Ultravisor (UV) and won't result + * in a negative return value. It copies the input to kernelspace, builds the + * request, sends the UV-call, and copies the result to userspace. + * + * The Attestation Request has two input and two outputs. + * ARCB and User Data are inputs for the UV generated by userspace. + * Measurement and Additional Data are outputs for userspace generated by UV. + * + * The Attestation Request Control Block (ARCB) is a cryptographically verified + * and secured request to UV and User Data is some plaintext data which is + * going to be included in the Attestation Measurement calculation. + * + * Measurement is a cryptographic measurement of the callers properties, + * optional data configured by the ARCB and the user data. If specified by the + * ARCB, UV will add some Additional Data to the measurement calculation. + * This Additional Data is then returned as well. + * + * If the Retrieve Attestation Measurement UV facility is not present, + * UV will return invalid command rc. This won't be fenced in the driver + * and does not result in a negative return value. + * + * Context: might sleep + * + * Return: 0 on success or a negative error code on error. + */ +static int uvio_attestation(struct uvio_ioctl_cb *uv_ioctl) +{ + struct uv_cb_attest *uvcb_attest = NULL; + struct uvio_attest *uvio_attest = NULL; + u8 *measurement = NULL; + u8 *add_data = NULL; + u8 *arcb = NULL; + int ret; + + ret = -EINVAL; + if (uv_ioctl->argument_len != sizeof(*uvio_attest)) + goto out; + + ret = -ENOMEM; + uvio_attest = kzalloc(sizeof(*uvio_attest), GFP_KERNEL); + if (!uvio_attest) + goto out; + + ret = get_uvio_attest(uv_ioctl, uvio_attest); + if (ret) + goto out; + + ret = -ENOMEM; + arcb = kvzalloc(uvio_attest->arcb_len, GFP_KERNEL); + measurement = kvzalloc(uvio_attest->meas_len, GFP_KERNEL); + if (!arcb || !measurement) + goto out; + + if (uvio_attest->add_data_len) { + add_data = kvzalloc(uvio_attest->add_data_len, GFP_KERNEL); + if (!add_data) + goto out; + } + + uvcb_attest = kzalloc(sizeof(*uvcb_attest), GFP_KERNEL); + if (!uvcb_attest) + goto out; + + ret = uvio_build_uvcb_attest(uvcb_attest, arcb, measurement, add_data, uvio_attest); + if (ret) + goto out; + + uv_call_sched(0, (u64)uvcb_attest); + + uv_ioctl->uv_rc = uvcb_attest->header.rc; + uv_ioctl->uv_rrc = uvcb_attest->header.rrc; + + ret = uvio_copy_attest_result_to_user(uvcb_attest, uv_ioctl, measurement, add_data, + uvio_attest); +out: + kvfree(arcb); + kvfree(measurement); + kvfree(add_data); + kfree(uvio_attest); + kfree(uvcb_attest); + return ret; +} + +static int uvio_copy_and_check_ioctl(struct uvio_ioctl_cb *ioctl, void __user *argp) +{ + if (copy_from_user(ioctl, argp, sizeof(*ioctl))) + return -EFAULT; + if (ioctl->flags != 0) + return -EINVAL; + if (memchr_inv(ioctl->reserved14, 0, sizeof(ioctl->reserved14))) + return -EINVAL; + + return 0; +} + +/* + * IOCTL entry point for the Ultravisor device. + */ +static long uvio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) +{ + void __user *argp = (void __user *)arg; + struct uvio_ioctl_cb uv_ioctl = { }; + long ret; + + switch (cmd) { + case UVIO_IOCTL_ATT: + ret = uvio_copy_and_check_ioctl(&uv_ioctl, argp); + if (ret) + return ret; + ret = uvio_attestation(&uv_ioctl); + break; + default: + ret = -ENOIOCTLCMD; + break; + } + if (ret) + return ret; + + if (copy_to_user(argp, &uv_ioctl, sizeof(uv_ioctl))) + ret = -EFAULT; + + return ret; +} + +static const struct file_operations uvio_dev_fops = { + .owner = THIS_MODULE, + .unlocked_ioctl = uvio_ioctl, + .llseek = no_llseek, +}; + +static struct miscdevice uvio_dev_miscdev = { + .minor = MISC_DYNAMIC_MINOR, + .name = UVIO_DEVICE_NAME, + .fops = &uvio_dev_fops, +}; + +static void __exit uvio_dev_exit(void) +{ + misc_deregister(&uvio_dev_miscdev); +} + +static int __init uvio_dev_init(void) +{ + if (!test_facility(158)) + return -ENXIO; + return misc_register(&uvio_dev_miscdev); +} + +module_init(uvio_dev_init); +module_exit(uvio_dev_exit); + +MODULE_AUTHOR("IBM Corporation"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Ultravisor UAPI driver"); From cbac924200b838cfb8d8b1415113d788089dc50b Mon Sep 17 00:00:00 2001 From: Steffen Eiden Date: Tue, 10 May 2022 14:47:24 +0000 Subject: [PATCH 2/4] selftests: drivers/s390x: Add uvdevice tests Adds some selftests to test ioctl error paths of the uv-uapi. The Kconfig S390_UV_UAPI must be selected and the Ultravisor facility must be available. The test can be executed by non-root, however, the uvdevice special file /dev/uv must be accessible for reading and writing which may imply root privileges. ./test-uv-device TAP version 13 1..6 # Starting 6 tests from 3 test cases. # RUN uvio_fixture.att.fault_ioctl_arg ... # OK uvio_fixture.att.fault_ioctl_arg ok 1 uvio_fixture.att.fault_ioctl_arg # RUN uvio_fixture.att.fault_uvio_arg ... # OK uvio_fixture.att.fault_uvio_arg ok 2 uvio_fixture.att.fault_uvio_arg # RUN uvio_fixture.att.inval_ioctl_cb ... # OK uvio_fixture.att.inval_ioctl_cb ok 3 uvio_fixture.att.inval_ioctl_cb # RUN uvio_fixture.att.inval_ioctl_cmd ... # OK uvio_fixture.att.inval_ioctl_cmd ok 4 uvio_fixture.att.inval_ioctl_cmd # RUN attest_fixture.att_inval_request ... # OK attest_fixture.att_inval_request ok 5 attest_fixture.att_inval_request # RUN attest_fixture.att_inval_addr ... # OK attest_fixture.att_inval_addr ok 6 attest_fixture.att_inval_addr # PASSED: 6 / 6 tests passed. # Totals: pass:6 fail:0 xfail:0 xpass:0 skip:0 error:0 Signed-off-by: Steffen Eiden Acked-by: Janosch Frank Message-Id: <20220510144724.3321985-3-seiden@linux.ibm.com> Link: https://lore.kernel.org/kvm/20220510144724.3321985-3-seiden@linux.ibm.com/ Signed-off-by: Janosch Frank --- MAINTAINERS | 1 + tools/testing/selftests/Makefile | 1 + tools/testing/selftests/drivers/.gitignore | 1 + .../selftests/drivers/s390x/uvdevice/Makefile | 22 ++ .../selftests/drivers/s390x/uvdevice/config | 1 + .../drivers/s390x/uvdevice/test_uvdevice.c | 276 ++++++++++++++++++ 6 files changed, 302 insertions(+) create mode 100644 tools/testing/selftests/drivers/s390x/uvdevice/Makefile create mode 100644 tools/testing/selftests/drivers/s390x/uvdevice/config create mode 100644 tools/testing/selftests/drivers/s390x/uvdevice/test_uvdevice.c diff --git a/MAINTAINERS b/MAINTAINERS index a74488b7bb7c..bc6fae05ee4b 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -10784,6 +10784,7 @@ F: arch/s390/kernel/uv.c F: arch/s390/kvm/ F: arch/s390/mm/gmap.c F: drivers/s390/char/uvdevice.c +F: tools/testing/selftests/drivers/s390x/uvdevice/ F: tools/testing/selftests/kvm/*/s390x/ F: tools/testing/selftests/kvm/s390x/ diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile index 2319ec87f53d..d6b307371ef7 100644 --- a/tools/testing/selftests/Makefile +++ b/tools/testing/selftests/Makefile @@ -10,6 +10,7 @@ TARGETS += core TARGETS += cpufreq TARGETS += cpu-hotplug TARGETS += drivers/dma-buf +TARGETS += drivers/s390x/uvdevice TARGETS += efivarfs TARGETS += exec TARGETS += filesystems diff --git a/tools/testing/selftests/drivers/.gitignore b/tools/testing/selftests/drivers/.gitignore index ca74f2e1c719..09e23b5afa96 100644 --- a/tools/testing/selftests/drivers/.gitignore +++ b/tools/testing/selftests/drivers/.gitignore @@ -1,2 +1,3 @@ # SPDX-License-Identifier: GPL-2.0-only /dma-buf/udmabuf +/s390x/uvdevice/test_uvdevice diff --git a/tools/testing/selftests/drivers/s390x/uvdevice/Makefile b/tools/testing/selftests/drivers/s390x/uvdevice/Makefile new file mode 100644 index 000000000000..5e701d2708d4 --- /dev/null +++ b/tools/testing/selftests/drivers/s390x/uvdevice/Makefile @@ -0,0 +1,22 @@ +include ../../../../../build/Build.include + +UNAME_M := $(shell uname -m) + +ifneq ($(UNAME_M),s390x) +nothing: +.PHONY: all clean run_tests install +.SILENT: +else + +TEST_GEN_PROGS := test_uvdevice + +top_srcdir ?= ../../../../../.. +KSFT_KHDR_INSTALL := 1 +khdr_dir = $(top_srcdir)/usr/include +LINUX_TOOL_ARCH_INCLUDE = $(top_srcdir)/tools/arch/$(ARCH)/include + +CFLAGS += -Wall -Werror -static -I$(khdr_dir) -I$(LINUX_TOOL_ARCH_INCLUDE) + +include ../../../lib.mk + +endif diff --git a/tools/testing/selftests/drivers/s390x/uvdevice/config b/tools/testing/selftests/drivers/s390x/uvdevice/config new file mode 100644 index 000000000000..f28a04b99eff --- /dev/null +++ b/tools/testing/selftests/drivers/s390x/uvdevice/config @@ -0,0 +1 @@ +CONFIG_S390_UV_UAPI=y diff --git a/tools/testing/selftests/drivers/s390x/uvdevice/test_uvdevice.c b/tools/testing/selftests/drivers/s390x/uvdevice/test_uvdevice.c new file mode 100644 index 000000000000..ea0cdc37b44f --- /dev/null +++ b/tools/testing/selftests/drivers/s390x/uvdevice/test_uvdevice.c @@ -0,0 +1,276 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * selftest for the Ultravisor UAPI device + * + * Copyright IBM Corp. 2022 + * Author(s): Steffen Eiden + */ + +#include +#include +#include +#include +#include + +#include + +#include "../../../kselftest_harness.h" + +#define UV_PATH "/dev/uv" +#define BUFFER_SIZE 0x200 +FIXTURE(uvio_fixture) { + int uv_fd; + struct uvio_ioctl_cb uvio_ioctl; + uint8_t buffer[BUFFER_SIZE]; + __u64 fault_page; +}; + +FIXTURE_VARIANT(uvio_fixture) { + unsigned long ioctl_cmd; + uint32_t arg_size; +}; + +FIXTURE_VARIANT_ADD(uvio_fixture, att) { + .ioctl_cmd = UVIO_IOCTL_ATT, + .arg_size = sizeof(struct uvio_attest), +}; + +FIXTURE_SETUP(uvio_fixture) +{ + self->uv_fd = open(UV_PATH, O_ACCMODE); + + self->uvio_ioctl.argument_addr = (__u64)self->buffer; + self->uvio_ioctl.argument_len = variant->arg_size; + self->fault_page = + (__u64)mmap(NULL, (size_t)getpagesize(), PROT_NONE, MAP_ANONYMOUS, -1, 0); +} + +FIXTURE_TEARDOWN(uvio_fixture) +{ + if (self->uv_fd) + close(self->uv_fd); + munmap((void *)self->fault_page, (size_t)getpagesize()); +} + +TEST_F(uvio_fixture, fault_ioctl_arg) +{ + int rc, errno_cache; + + rc = ioctl(self->uv_fd, variant->ioctl_cmd, NULL); + errno_cache = errno; + ASSERT_EQ(rc, -1); + ASSERT_EQ(errno_cache, EFAULT); + + rc = ioctl(self->uv_fd, variant->ioctl_cmd, self->fault_page); + errno_cache = errno; + ASSERT_EQ(rc, -1); + ASSERT_EQ(errno_cache, EFAULT); +} + +TEST_F(uvio_fixture, fault_uvio_arg) +{ + int rc, errno_cache; + + self->uvio_ioctl.argument_addr = 0; + rc = ioctl(self->uv_fd, variant->ioctl_cmd, &self->uvio_ioctl); + errno_cache = errno; + ASSERT_EQ(rc, -1); + ASSERT_EQ(errno_cache, EFAULT); + + self->uvio_ioctl.argument_addr = self->fault_page; + rc = ioctl(self->uv_fd, variant->ioctl_cmd, &self->uvio_ioctl); + errno_cache = errno; + ASSERT_EQ(rc, -1); + ASSERT_EQ(errno_cache, EFAULT); +} + +/* + * Test to verify that IOCTLs with invalid values in the ioctl_control block + * are rejected. + */ +TEST_F(uvio_fixture, inval_ioctl_cb) +{ + int rc, errno_cache; + + self->uvio_ioctl.argument_len = 0; + rc = ioctl(self->uv_fd, variant->ioctl_cmd, &self->uvio_ioctl); + errno_cache = errno; + ASSERT_EQ(rc, -1); + ASSERT_EQ(errno_cache, EINVAL); + + self->uvio_ioctl.argument_len = (uint32_t)-1; + rc = ioctl(self->uv_fd, variant->ioctl_cmd, &self->uvio_ioctl); + errno_cache = errno; + ASSERT_EQ(rc, -1); + ASSERT_EQ(errno_cache, EINVAL); + self->uvio_ioctl.argument_len = variant->arg_size; + + self->uvio_ioctl.flags = (uint32_t)-1; + rc = ioctl(self->uv_fd, variant->ioctl_cmd, &self->uvio_ioctl); + errno_cache = errno; + ASSERT_EQ(rc, -1); + ASSERT_EQ(errno_cache, EINVAL); + self->uvio_ioctl.flags = 0; + + memset(self->uvio_ioctl.reserved14, 0xff, sizeof(self->uvio_ioctl.reserved14)); + rc = ioctl(self->uv_fd, variant->ioctl_cmd, &self->uvio_ioctl); + errno_cache = errno; + ASSERT_EQ(rc, -1); + ASSERT_EQ(errno_cache, EINVAL); + + memset(&self->uvio_ioctl, 0x11, sizeof(self->uvio_ioctl)); + rc = ioctl(self->uv_fd, variant->ioctl_cmd, &self->uvio_ioctl); + ASSERT_EQ(rc, -1); +} + +TEST_F(uvio_fixture, inval_ioctl_cmd) +{ + int rc, errno_cache; + uint8_t nr = _IOC_NR(variant->ioctl_cmd); + unsigned long cmds[] = { + _IOWR('a', nr, struct uvio_ioctl_cb), + _IOWR(UVIO_TYPE_UVC, nr, int), + _IO(UVIO_TYPE_UVC, nr), + _IOR(UVIO_TYPE_UVC, nr, struct uvio_ioctl_cb), + _IOW(UVIO_TYPE_UVC, nr, struct uvio_ioctl_cb), + }; + + for (size_t i = 0; i < ARRAY_SIZE(cmds); i++) { + rc = ioctl(self->uv_fd, cmds[i], &self->uvio_ioctl); + errno_cache = errno; + ASSERT_EQ(rc, -1); + ASSERT_EQ(errno_cache, ENOTTY); + } +} + +struct test_attest_buffer { + uint8_t arcb[0x180]; + uint8_t meas[64]; + uint8_t add[32]; +}; + +FIXTURE(attest_fixture) { + int uv_fd; + struct uvio_ioctl_cb uvio_ioctl; + struct uvio_attest uvio_attest; + struct test_attest_buffer attest_buffer; + __u64 fault_page; +}; + +FIXTURE_SETUP(attest_fixture) +{ + self->uv_fd = open(UV_PATH, O_ACCMODE); + + self->uvio_ioctl.argument_addr = (__u64)&self->uvio_attest; + self->uvio_ioctl.argument_len = sizeof(self->uvio_attest); + + self->uvio_attest.arcb_addr = (__u64)&self->attest_buffer.arcb; + self->uvio_attest.arcb_len = sizeof(self->attest_buffer.arcb); + + self->uvio_attest.meas_addr = (__u64)&self->attest_buffer.meas; + self->uvio_attest.meas_len = sizeof(self->attest_buffer.meas); + + self->uvio_attest.add_data_addr = (__u64)&self->attest_buffer.add; + self->uvio_attest.add_data_len = sizeof(self->attest_buffer.add); + self->fault_page = + (__u64)mmap(NULL, (size_t)getpagesize(), PROT_NONE, MAP_ANONYMOUS, -1, 0); +} + +FIXTURE_TEARDOWN(attest_fixture) +{ + if (self->uv_fd) + close(self->uv_fd); + munmap((void *)self->fault_page, (size_t)getpagesize()); +} + +static void att_inval_sizes_test(uint32_t *size, uint32_t max_size, bool test_zero, + struct __test_metadata *_metadata, + FIXTURE_DATA(attest_fixture) *self) +{ + int rc, errno_cache; + uint32_t tmp = *size; + + if (test_zero) { + *size = 0; + rc = ioctl(self->uv_fd, UVIO_IOCTL_ATT, &self->uvio_ioctl); + errno_cache = errno; + ASSERT_EQ(rc, -1); + ASSERT_EQ(errno_cache, EINVAL); + } + *size = max_size + 1; + rc = ioctl(self->uv_fd, UVIO_IOCTL_ATT, &self->uvio_ioctl); + errno_cache = errno; + ASSERT_EQ(rc, -1); + ASSERT_EQ(errno_cache, EINVAL); + *size = tmp; +} + +/* + * Test to verify that attestation IOCTLs with invalid values in the UVIO + * attestation control block are rejected. + */ +TEST_F(attest_fixture, att_inval_request) +{ + int rc, errno_cache; + + att_inval_sizes_test(&self->uvio_attest.add_data_len, UVIO_ATT_ADDITIONAL_MAX_LEN, + false, _metadata, self); + att_inval_sizes_test(&self->uvio_attest.meas_len, UVIO_ATT_MEASUREMENT_MAX_LEN, + true, _metadata, self); + att_inval_sizes_test(&self->uvio_attest.arcb_len, UVIO_ATT_ARCB_MAX_LEN, + true, _metadata, self); + + self->uvio_attest.reserved136 = (uint16_t)-1; + rc = ioctl(self->uv_fd, UVIO_IOCTL_ATT, &self->uvio_ioctl); + errno_cache = errno; + ASSERT_EQ(rc, -1); + ASSERT_EQ(errno_cache, EINVAL); + + memset(&self->uvio_attest, 0x11, sizeof(self->uvio_attest)); + rc = ioctl(self->uv_fd, UVIO_IOCTL_ATT, &self->uvio_ioctl); + ASSERT_EQ(rc, -1); +} + +static void att_inval_addr_test(__u64 *addr, struct __test_metadata *_metadata, + FIXTURE_DATA(attest_fixture) *self) +{ + int rc, errno_cache; + __u64 tmp = *addr; + + *addr = 0; + rc = ioctl(self->uv_fd, UVIO_IOCTL_ATT, &self->uvio_ioctl); + errno_cache = errno; + ASSERT_EQ(rc, -1); + ASSERT_EQ(errno_cache, EFAULT); + *addr = self->fault_page; + rc = ioctl(self->uv_fd, UVIO_IOCTL_ATT, &self->uvio_ioctl); + errno_cache = errno; + ASSERT_EQ(rc, -1); + ASSERT_EQ(errno_cache, EFAULT); + *addr = tmp; +} + +TEST_F(attest_fixture, att_inval_addr) +{ + att_inval_addr_test(&self->uvio_attest.arcb_addr, _metadata, self); + att_inval_addr_test(&self->uvio_attest.add_data_addr, _metadata, self); + att_inval_addr_test(&self->uvio_attest.meas_addr, _metadata, self); +} + +static void __attribute__((constructor)) __constructor_order_last(void) +{ + if (!__constructor_order) + __constructor_order = _CONSTRUCTOR_ORDER_BACKWARD; +} + +int main(int argc, char **argv) +{ + int fd = open(UV_PATH, O_ACCMODE); + + if (fd < 0) + ksft_exit_skip("No uv-device or cannot access " UV_PATH "\n" + "Enable CONFIG_S390_UV_UAPI and check the access rights on " + UV_PATH ".\n"); + close(fd); + return test_harness_run(argc, argv); +} From c783631b0bffe6060113ff0aafe5fdbd71bea793 Mon Sep 17 00:00:00 2001 From: Janis Schoetterl-Glausch Date: Thu, 12 May 2022 15:10:17 +0200 Subject: [PATCH 3/4] KVM: s390: Don't indicate suppression on dirtying, failing memop If user space uses a memop to emulate an instruction and that memop fails, the execution of the instruction ends. Instruction execution can end in different ways, one of which is suppression, which requires that the instruction execute like a no-op. A writing memop that spans multiple pages and fails due to key protection may have modified guest memory, as a result, the likely correct ending is termination. Therefore, do not indicate a suppressing instruction ending in this case. Signed-off-by: Janis Schoetterl-Glausch Reviewed-by: Christian Borntraeger Reviewed-by: Claudio Imbrenda Link: https://lore.kernel.org/r/20220512131019.2594948-2-scgl@linux.ibm.com Signed-off-by: Christian Borntraeger Signed-off-by: Janosch Frank --- Documentation/virt/kvm/api.rst | 6 ++++++ arch/s390/kvm/gaccess.c | 22 ++++++++++++++++++---- 2 files changed, 24 insertions(+), 4 deletions(-) diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index d13fa6600467..09353e27bdbc 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -3754,12 +3754,18 @@ in case of KVM_S390_MEMOP_F_CHECK_ONLY), the ioctl returns a positive error number indicating the type of exception. This exception is also raised directly at the corresponding VCPU if the flag KVM_S390_MEMOP_F_INJECT_EXCEPTION is set. +On protection exceptions, unless specified otherwise, the injected +translation-exception identifier (TEID) indicates suppression. If the KVM_S390_MEMOP_F_SKEY_PROTECTION flag is set, storage key protection is also in effect and may cause exceptions if accesses are prohibited given the access key designated by "key"; the valid range is 0..15. KVM_S390_MEMOP_F_SKEY_PROTECTION is available if KVM_CAP_S390_MEM_OP_EXTENSION is > 0. +Since the accessed memory may span multiple pages and those pages might have +different storage keys, it is possible that a protection exception occurs +after memory has been modified. In this case, if the exception is injected, +the TEID does not indicate suppression. Absolute read/write: ^^^^^^^^^^^^^^^^^^^^ diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/gaccess.c index d53a183c2005..227ed0009354 100644 --- a/arch/s390/kvm/gaccess.c +++ b/arch/s390/kvm/gaccess.c @@ -491,8 +491,8 @@ enum prot_type { PROT_TYPE_IEP = 4, }; -static int trans_exc(struct kvm_vcpu *vcpu, int code, unsigned long gva, - u8 ar, enum gacc_mode mode, enum prot_type prot) +static int trans_exc_ending(struct kvm_vcpu *vcpu, int code, unsigned long gva, u8 ar, + enum gacc_mode mode, enum prot_type prot, bool terminate) { struct kvm_s390_pgm_info *pgm = &vcpu->arch.pgm; struct trans_exc_code_bits *tec; @@ -520,6 +520,11 @@ static int trans_exc(struct kvm_vcpu *vcpu, int code, unsigned long gva, tec->b61 = 1; break; } + if (terminate) { + tec->b56 = 0; + tec->b60 = 0; + tec->b61 = 0; + } fallthrough; case PGM_ASCE_TYPE: case PGM_PAGE_TRANSLATION: @@ -552,6 +557,12 @@ static int trans_exc(struct kvm_vcpu *vcpu, int code, unsigned long gva, return code; } +static int trans_exc(struct kvm_vcpu *vcpu, int code, unsigned long gva, u8 ar, + enum gacc_mode mode, enum prot_type prot) +{ + return trans_exc_ending(vcpu, code, gva, ar, mode, prot, false); +} + static int get_vcpu_asce(struct kvm_vcpu *vcpu, union asce *asce, unsigned long ga, u8 ar, enum gacc_mode mode) { @@ -1109,8 +1120,11 @@ int access_guest_with_key(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, data += fragment_len; ga = kvm_s390_logical_to_effective(vcpu, ga + fragment_len); } - if (rc > 0) - rc = trans_exc(vcpu, rc, ga, ar, mode, prot); + if (rc > 0) { + bool terminate = (mode == GACC_STORE) && (idx > 0); + + rc = trans_exc_ending(vcpu, rc, ga, ar, mode, prot, terminate); + } out_unlock: if (need_ipte_lock) ipte_unlock(vcpu); From c71159648c3cf0f7127ddc0bdf3eb4d7885210df Mon Sep 17 00:00:00 2001 From: Janis Schoetterl-Glausch Date: Thu, 12 May 2022 15:10:18 +0200 Subject: [PATCH 4/4] KVM: s390: selftest: Test suppression indication on key prot exception Check that suppression is not indicated on injection of a key checked protection exception caused by a memop after it already modified guest memory, as that violates the definition of suppression. Signed-off-by: Janis Schoetterl-Glausch Reviewed-by: Christian Borntraeger Link: https://lore.kernel.org/r/20220512131019.2594948-3-scgl@linux.ibm.com Signed-off-by: Christian Borntraeger Signed-off-by: Janosch Frank --- tools/testing/selftests/kvm/s390x/memop.c | 46 ++++++++++++++++++++++- 1 file changed, 45 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/kvm/s390x/memop.c b/tools/testing/selftests/kvm/s390x/memop.c index b04c2c1b3c30..49f26f544127 100644 --- a/tools/testing/selftests/kvm/s390x/memop.c +++ b/tools/testing/selftests/kvm/s390x/memop.c @@ -10,6 +10,8 @@ #include #include +#include + #include "test_util.h" #include "kvm_util.h" @@ -194,6 +196,7 @@ static int err_memop_ioctl(struct test_vcpu vcpu, struct kvm_s390_mem_op *ksmo) #define SIDA_OFFSET(o) ._sida_offset = 1, .sida_offset = (o) #define AR(a) ._ar = 1, .ar = (a) #define KEY(a) .f_key = 1, .key = (a) +#define INJECT .f_inject = 1 #define CHECK_N_DO(f, ...) ({ f(__VA_ARGS__, CHECK_ONLY); f(__VA_ARGS__); }) @@ -430,9 +433,18 @@ static void test_copy_key_fetch_prot(void) TEST_ASSERT(rv == 4, "Should result in protection exception"); \ }) +static void guest_error_key(void) +{ + GUEST_SYNC(STAGE_INITED); + set_storage_key_range(mem1, PAGE_SIZE, 0x18); + set_storage_key_range(mem1 + PAGE_SIZE, sizeof(mem1) - PAGE_SIZE, 0x98); + GUEST_SYNC(STAGE_SKEYS_SET); + GUEST_SYNC(STAGE_IDLED); +} + static void test_errors_key(void) { - struct test_default t = test_default_init(guest_copy_key_fetch_prot); + struct test_default t = test_default_init(guest_error_key); HOST_SYNC(t.vcpu, STAGE_INITED); HOST_SYNC(t.vcpu, STAGE_SKEYS_SET); @@ -446,6 +458,37 @@ static void test_errors_key(void) kvm_vm_free(t.kvm_vm); } +static void test_termination(void) +{ + struct test_default t = test_default_init(guest_error_key); + uint64_t prefix; + uint64_t teid; + uint64_t teid_mask = BIT(63 - 56) | BIT(63 - 60) | BIT(63 - 61); + uint64_t psw[2]; + + HOST_SYNC(t.vcpu, STAGE_INITED); + HOST_SYNC(t.vcpu, STAGE_SKEYS_SET); + + /* vcpu, mismatching keys after first page */ + ERR_PROT_MOP(t.vcpu, LOGICAL, WRITE, mem1, t.size, GADDR_V(mem1), KEY(1), INJECT); + /* + * The memop injected a program exception and the test needs to check the + * Translation-Exception Identification (TEID). It is necessary to run + * the guest in order to be able to read the TEID from guest memory. + * Set the guest program new PSW, so the guest state is not clobbered. + */ + prefix = t.run->s.regs.prefix; + psw[0] = t.run->psw_mask; + psw[1] = t.run->psw_addr; + MOP(t.vm, ABSOLUTE, WRITE, psw, sizeof(psw), GADDR(prefix + 464)); + HOST_SYNC(t.vcpu, STAGE_IDLED); + MOP(t.vm, ABSOLUTE, READ, &teid, sizeof(teid), GADDR(prefix + 168)); + /* Bits 56, 60, 61 form a code, 0 being the only one allowing for termination */ + ASSERT_EQ(teid & teid_mask, 0); + + kvm_vm_free(t.kvm_vm); +} + static void test_errors_key_storage_prot_override(void) { struct test_default t = test_default_init(guest_copy_key_fetch_prot); @@ -668,6 +711,7 @@ int main(int argc, char *argv[]) test_copy_key_fetch_prot(); test_copy_key_fetch_prot_override(); test_errors_key(); + test_termination(); test_errors_key_storage_prot_override(); test_errors_key_fetch_prot_override_not_enabled(); test_errors_key_fetch_prot_override_enabled();