2023-06-15 10:07:14

by Steffen Eiden

[permalink] [raw]
Subject: [PATCH v5 0/7] s390/uvdevice: Expose secret UVCs

IBM Secure Execution guests may want to inject secrets into the Ultravisor(UV).
Also they should be able to know which secrets the UV possesses and prevent the
further addition of more secrets.

Therefore, add three new Ultravisor-Calls and expose them via the uvdevice: Add
Secret, List Secrets, and Lock Secrets. The uvdevice still acts as the
messenger only and does not inspect or modify the requests. Only some sanity
checks are made to prevent the kernel from corruption.
Also add a new IOCTL to get information about the supported UV-calls of the
uvdevice. As userspace wants to know which secrets, types, etc. are supported
expose the corresponding UV Query info data to userspace via sysfs.

The series contains:
* A patch to export uv_info unconditionally
* A new info IOCTL, giving information about the capabilities of the uvdevice and UV
* 3 patches adding new Ultravisor-Calls and expose them to userspace
* A patch replacing scnprintf with sysfs_emit in arch/s390/kernel/uv.c
* A patch with an Ultravisor Query Info update for the new secret related information

Changes for v5:
* fix Kconfig for uvdevice
* add PATCH to always export `uv_info`
* fix oopsie
see diff below

Changes for v4:
* more nits from Janosch

Changes for v3:
* misc nits from Janosch

Changes for v2:
* use __set_bit instead of the atomic set_bit (Heiko)
* add a patch for replacing scnprintf with sysfs_emit in arch/s390/kernel/uv.c (Heiko)
* use scnprintf instead of sysfs_emit for the new sysfs entries in the last patch (Heiko)
* use hex values in struct definitions (Claudio)

Steffen

DIFF v4->v5

diff --git a/arch/s390/boot/uv.c b/arch/s390/boot/uv.c
index cdffc395f1cd..1e66d2cbb096 100644
--- a/arch/s390/boot/uv.c
+++ b/arch/s390/boot/uv.c
@@ -50,7 +50,7 @@ void uv_query_info(void)
uv_info.supp_add_secret_req_ver = uvcb.supp_add_secret_req_ver;
uv_info.supp_add_secret_pcf = uvcb.supp_add_secret_pcf;
uv_info.supp_secret_types = uvcb.supp_secret_types;
- uv_info.max_secrets = uvcb.max_secrets
+ uv_info.max_secrets = uvcb.max_secrets;
}

#ifdef CONFIG_PROTECTED_VIRTUALIZATION_GUEST
diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
index 0687fc0360fe..6a0153289ace 100644
--- a/arch/s390/kernel/uv.c
+++ b/arch/s390/kernel/uv.c
@@ -23,12 +23,20 @@
int __bootdata_preserved(prot_virt_guest);
#endif

+/*
+ * uv_info contains both host and guest information but it's currently only
+ * expected to be used within modules if it's the KVM module or for
+ * any PV guest module.
+ *
+ * The kernel itself will write these values once in uv_query_info()
+ * and then make some of them readable via a sysfs interface.
+ */
struct uv_info __bootdata_preserved(uv_info);
+EXPORT_SYMBOL(uv_info);

#if IS_ENABLED(CONFIG_KVM)
int __bootdata_preserved(prot_virt_host);
EXPORT_SYMBOL(prot_virt_host);
-EXPORT_SYMBOL(uv_info);

static int __init uv_init(phys_addr_t stor_base, unsigned long stor_len)
{
diff --git a/drivers/s390/char/Kconfig b/drivers/s390/char/Kconfig
index 80c4e5101c97..8a03af5ee5b3 100644
--- a/drivers/s390/char/Kconfig
+++ b/drivers/s390/char/Kconfig
@@ -96,7 +96,7 @@ config SCLP_OFB
config S390_UV_UAPI
def_tristate m
prompt "Ultravisor userspace API"
- depends on S390
+ depends on S390 && (KVM || PROTECTED_VIRTUALIZATION_GUEST)
help
Selecting exposes parts of the UV interface to userspace
by providing a misc character device at /dev/uv.
diff --git a/drivers/s390/char/uvdevice.c b/drivers/s390/char/uvdevice.c
index 79f694e04ac4..144cd2e03590 100644
--- a/drivers/s390/char/uvdevice.c
+++ b/drivers/s390/char/uvdevice.c
@@ -78,7 +78,7 @@ static int uvio_uvdev_info(struct uvio_ioctl_cb *uv_ioctl)
return -EFAULT;

uv_ioctl->uv_rc = UVC_RC_EXECUTED;
- return 0;
+ return 0;
}

static int uvio_build_uvcb_attest(struct uv_cb_attest *uvcb_attest, u8 *arcb,

END DIFFv4->v5

Steffen Eiden (7):
s390/uv: Always export uv_info
s390/uvdevice: Add info IOCTL
s390/uvdevice: Add 'Add Secret' UVC
s390/uvdevice: Add 'List Secrets' UVC
s390/uvdevice: Add 'Lock Secret Store' UVC
s390/uv: replace scnprintf with sysfs_emit
s390/uv: Update query for secret-UVCs

arch/s390/boot/uv.c | 4 +
arch/s390/include/asm/uv.h | 32 +++-
arch/s390/include/uapi/asm/uvdevice.h | 53 +++++-
arch/s390/kernel/uv.c | 108 ++++++++----
drivers/s390/char/Kconfig | 2 +-
drivers/s390/char/uvdevice.c | 231 +++++++++++++++++++++++++-
6 files changed, 386 insertions(+), 44 deletions(-)

--
2.40.1



2023-06-15 10:12:47

by Steffen Eiden

[permalink] [raw]
Subject: [PATCH v5 2/7] s390/uvdevice: Add info IOCTL

Add an IOCTL that allows userspace to find out which IOCTLs the uvdevice
supports without trial and error.

Explicitly expose the IOCTL nr for the request types.

Signed-off-by: Steffen Eiden <[email protected]>
Reviewed-by: Janosch Frank <[email protected]>
---
arch/s390/include/uapi/asm/uvdevice.h | 42 ++++++++++++++-
drivers/s390/char/Kconfig | 2 +-
drivers/s390/char/uvdevice.c | 77 ++++++++++++++++++++++++---
3 files changed, 112 insertions(+), 9 deletions(-)

diff --git a/arch/s390/include/uapi/asm/uvdevice.h b/arch/s390/include/uapi/asm/uvdevice.h
index 10a5ac918e02..9d9b684836c2 100644
--- a/arch/s390/include/uapi/asm/uvdevice.h
+++ b/arch/s390/include/uapi/asm/uvdevice.h
@@ -32,6 +32,33 @@ struct uvio_attest {
__u16 reserved136; /* 0x0136 */
};

+/**
+ * uvio_uvdev_info - Information of supported functions
+ * @supp_uvio_cmds - supported IOCTLs by this device
+ * @supp_uv_cmds - supported UVCs corresponding to the IOCTL
+ *
+ * UVIO request to get information about supported request types by this
+ * uvdevice and the Ultravisor. Everything is output. Bits are in LSB0
+ * ordering. If the bit is set in both, @supp_uvio_cmds and @supp_uv_cmds, the
+ * uvdevice and the Ultravisor support that call.
+ *
+ * Note that bit 0 (UVIO_IOCTL_UVDEV_INFO_NR) is always zero for `supp_uv_cmds`
+ * as there is no corresponding UV-call.
+ */
+struct uvio_uvdev_info {
+ /*
+ * If bit `n` is set, this device supports the IOCTL with nr `n`.
+ */
+ __u64 supp_uvio_cmds;
+ /*
+ * If bit `n` is set, the Ultravisor(UV) supports the UV-call
+ * corresponding to the IOCTL with nr `n` in the calling contextx (host
+ * or guest). The value is only valid if the corresponding bit in
+ * @supp_uvio_cmds is set as well.
+ */
+ __u64 supp_uv_cmds;
+};
+
/*
* 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
@@ -46,6 +73,19 @@ struct uvio_attest {
#define UVIO_DEVICE_NAME "uv"
#define UVIO_TYPE_UVC 'u'

-#define UVIO_IOCTL_ATT _IOWR(UVIO_TYPE_UVC, 0x01, struct uvio_ioctl_cb)
+enum UVIO_IOCTL_NR {
+ UVIO_IOCTL_UVDEV_INFO_NR = 0x00,
+ UVIO_IOCTL_ATT_NR,
+ /* must be the last entry */
+ UVIO_IOCTL_NUM_IOCTLS
+};
+
+#define UVIO_IOCTL(nr) _IOWR(UVIO_TYPE_UVC, nr, struct uvio_ioctl_cb)
+#define UVIO_IOCTL_UVDEV_INFO UVIO_IOCTL(UVIO_IOCTL_UVDEV_INFO_NR)
+#define UVIO_IOCTL_ATT UVIO_IOCTL(UVIO_IOCTL_ATT_NR)
+
+#define UVIO_SUPP_CALL(nr) (1ULL << (nr))
+#define UVIO_SUPP_UDEV_INFO UVIO_SUPP_CALL(UVIO_IOCTL_UDEV_INFO_NR)
+#define UVIO_SUPP_ATT UVIO_SUPP_CALL(UVIO_IOCTL_ATT_NR)

#endif /* __S390_ASM_UVDEVICE_H */
diff --git a/drivers/s390/char/Kconfig b/drivers/s390/char/Kconfig
index 80c4e5101c97..8a03af5ee5b3 100644
--- a/drivers/s390/char/Kconfig
+++ b/drivers/s390/char/Kconfig
@@ -96,7 +96,7 @@ config SCLP_OFB
config S390_UV_UAPI
def_tristate m
prompt "Ultravisor userspace API"
- depends on S390
+ depends on S390 && (KVM || PROTECTED_VIRTUALIZATION_GUEST)
help
Selecting exposes parts of the UV interface to userspace
by providing a misc character device at /dev/uv.
diff --git a/drivers/s390/char/uvdevice.c b/drivers/s390/char/uvdevice.c
index 1d40457c7b10..7d7866be389b 100644
--- a/drivers/s390/char/uvdevice.c
+++ b/drivers/s390/char/uvdevice.c
@@ -32,6 +32,52 @@
#include <asm/uvdevice.h>
#include <asm/uv.h>

+#define BIT_UVIO_INTERNAL U32_MAX
+/* Mapping from IOCTL-nr to UVC-bit */
+static const u32 ioctl_nr_to_uvc_bit[] __initconst = {
+ [UVIO_IOCTL_UVDEV_INFO_NR] = BIT_UVIO_INTERNAL,
+ [UVIO_IOCTL_ATT_NR] = BIT_UVC_CMD_RETR_ATTEST,
+};
+
+static_assert(ARRAY_SIZE(ioctl_nr_to_uvc_bit) == UVIO_IOCTL_NUM_IOCTLS);
+
+static struct uvio_uvdev_info uvdev_info = {
+ .supp_uvio_cmds = GENMASK_ULL(UVIO_IOCTL_NUM_IOCTLS - 1, 0),
+};
+
+static void __init set_supp_uv_cmds(unsigned long *supp_uv_cmds)
+{
+ int i;
+
+ for (i = 0; i < UVIO_IOCTL_NUM_IOCTLS; i++) {
+ if (ioctl_nr_to_uvc_bit[i] == BIT_UVIO_INTERNAL)
+ continue;
+ if (!test_bit_inv(ioctl_nr_to_uvc_bit[i], uv_info.inst_calls_list))
+ continue;
+ __set_bit(i, supp_uv_cmds);
+ }
+}
+
+/**
+ * uvio_uvdev_info() - get information about the uvdevice
+ *
+ * @uv_ioctl: ioctl control block
+ *
+ * Lists all IOCTLs that are supported by this uvdevice
+ */
+static int uvio_uvdev_info(struct uvio_ioctl_cb *uv_ioctl)
+{
+ void __user *user_buf_arg = (void __user *)uv_ioctl->argument_addr;
+
+ if (uv_ioctl->argument_len < sizeof(uvdev_info))
+ return -EINVAL;
+ if (copy_to_user(user_buf_arg, &uvdev_info, sizeof(uvdev_info)))
+ return -EFAULT;
+
+ uv_ioctl->uv_rc = UVC_RC_EXECUTED;
+ return 0;
+}
+
static int uvio_build_uvcb_attest(struct uv_cb_attest *uvcb_attest, u8 *arcb,
u8 *meas, u8 *add_data, struct uvio_attest *uvio_attest)
{
@@ -185,8 +231,19 @@ static int uvio_attestation(struct uvio_ioctl_cb *uv_ioctl)
return ret;
}

-static int uvio_copy_and_check_ioctl(struct uvio_ioctl_cb *ioctl, void __user *argp)
+static int uvio_copy_and_check_ioctl(struct uvio_ioctl_cb *ioctl, void __user *argp,
+ unsigned long cmd)
{
+ u8 nr = _IOC_NR(cmd);
+
+ if (_IOC_DIR(cmd) != (_IOC_READ | _IOC_WRITE))
+ return -ENOIOCTLCMD;
+ if (_IOC_TYPE(cmd) != UVIO_TYPE_UVC)
+ return -ENOIOCTLCMD;
+ if (nr >= UVIO_IOCTL_NUM_IOCTLS)
+ return -ENOIOCTLCMD;
+ if (_IOC_SIZE(cmd) != sizeof(*ioctl))
+ return -ENOIOCTLCMD;
if (copy_from_user(ioctl, argp, sizeof(*ioctl)))
return -EFAULT;
if (ioctl->flags != 0)
@@ -194,7 +251,7 @@ static int uvio_copy_and_check_ioctl(struct uvio_ioctl_cb *ioctl, void __user *a
if (memchr_inv(ioctl->reserved14, 0, sizeof(ioctl->reserved14)))
return -EINVAL;

- return 0;
+ return nr;
}

/*
@@ -205,12 +262,17 @@ 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;
+ int nr;
+
+ nr = uvio_copy_and_check_ioctl(&uv_ioctl, argp, cmd);
+ if (nr < 0)
+ return nr;

- switch (cmd) {
- case UVIO_IOCTL_ATT:
- ret = uvio_copy_and_check_ioctl(&uv_ioctl, argp);
- if (ret)
- return ret;
+ switch (nr) {
+ case UVIO_IOCTL_UVDEV_INFO_NR:
+ ret = uvio_uvdev_info(&uv_ioctl);
+ break;
+ case UVIO_IOCTL_ATT_NR:
ret = uvio_attestation(&uv_ioctl);
break;
default:
@@ -245,6 +307,7 @@ static void __exit uvio_dev_exit(void)

static int __init uvio_dev_init(void)
{
+ set_supp_uv_cmds((unsigned long *)&uvdev_info.supp_uv_cmds);
return misc_register(&uvio_dev_miscdev);
}

--
2.40.1


2023-06-15 10:15:37

by Steffen Eiden

[permalink] [raw]
Subject: [PATCH v5 5/7] s390/uvdevice: Add 'Lock Secret Store' UVC

Userspace can call the Lock Secret Store Ultravisor Call
using IOCTLs on the uvdevice. The Lock Secret Store UV call
disables all additions of secrets for the future.

The uvdevice is merely transporting the request from userspace to the
Ultravisor.

Signed-off-by: Steffen Eiden <[email protected]>
Reviewed-by: Janosch Frank <[email protected]>
---
arch/s390/include/asm/uv.h | 2 ++
arch/s390/include/uapi/asm/uvdevice.h | 3 +++
drivers/s390/char/uvdevice.c | 39 +++++++++++++++++++++++++++
3 files changed, 44 insertions(+)

diff --git a/arch/s390/include/asm/uv.h b/arch/s390/include/asm/uv.h
index eeb945a7c80e..1d47b3e40be8 100644
--- a/arch/s390/include/asm/uv.h
+++ b/arch/s390/include/asm/uv.h
@@ -60,6 +60,7 @@
#define UVC_CMD_RETR_ATTEST 0x1020
#define UVC_CMD_ADD_SECRET 0x1031
#define UVC_CMD_LIST_SECRETS 0x1033
+#define UVC_CMD_LOCK_SECRETS 0x1034

/* Bits in installed uv calls */
enum uv_cmds_inst {
@@ -92,6 +93,7 @@ enum uv_cmds_inst {
BIT_UVC_CMD_RETR_ATTEST = 28,
BIT_UVC_CMD_ADD_SECRET = 29,
BIT_UVC_CMD_LIST_SECRETS = 30,
+ BIT_UVC_CMD_LOCK_SECRETS = 31,
};

enum uv_feat_ind {
diff --git a/arch/s390/include/uapi/asm/uvdevice.h b/arch/s390/include/uapi/asm/uvdevice.h
index 76045da44868..b9c2f14a6af3 100644
--- a/arch/s390/include/uapi/asm/uvdevice.h
+++ b/arch/s390/include/uapi/asm/uvdevice.h
@@ -80,6 +80,7 @@ enum UVIO_IOCTL_NR {
UVIO_IOCTL_ATT_NR,
UVIO_IOCTL_ADD_SECRET_NR,
UVIO_IOCTL_LIST_SECRETS_NR,
+ UVIO_IOCTL_LOCK_SECRETS_NR,
/* must be the last entry */
UVIO_IOCTL_NUM_IOCTLS
};
@@ -89,11 +90,13 @@ enum UVIO_IOCTL_NR {
#define UVIO_IOCTL_ATT UVIO_IOCTL(UVIO_IOCTL_ATT_NR)
#define UVIO_IOCTL_ADD_SECRET UVIO_IOCTL(UVIO_IOCTL_ADD_SECRET_NR)
#define UVIO_IOCTL_LIST_SECRETS UVIO_IOCTL(UVIO_IOCTL_LIST_SECRETS_NR)
+#define UVIO_IOCTL_LOCK_SECRETS UVIO_IOCTL(UVIO_IOCTL_LOCK_SECRETS_NR)

#define UVIO_SUPP_CALL(nr) (1ULL << (nr))
#define UVIO_SUPP_UDEV_INFO UVIO_SUPP_CALL(UVIO_IOCTL_UDEV_INFO_NR)
#define UVIO_SUPP_ATT UVIO_SUPP_CALL(UVIO_IOCTL_ATT_NR)
#define UVIO_SUPP_ADD_SECRET UVIO_SUPP_CALL(UVIO_IOCTL_ADD_SECRET_NR)
#define UVIO_SUPP_LIST_SECRETS UVIO_SUPP_CALL(UVIO_IOCTL_LIST_SECRETS_NR)
+#define UVIO_SUPP_LOCK_SECRETS UVIO_SUPP_CALL(UVIO_IOCTL_LOCK_SECRETS_NR)

#endif /* __S390_ASM_UVDEVICE_H */
diff --git a/drivers/s390/char/uvdevice.c b/drivers/s390/char/uvdevice.c
index 70502c4ec290..144cd2e03590 100644
--- a/drivers/s390/char/uvdevice.c
+++ b/drivers/s390/char/uvdevice.c
@@ -39,6 +39,7 @@ static const u32 ioctl_nr_to_uvc_bit[] __initconst = {
[UVIO_IOCTL_ATT_NR] = BIT_UVC_CMD_RETR_ATTEST,
[UVIO_IOCTL_ADD_SECRET_NR] = BIT_UVC_CMD_ADD_SECRET,
[UVIO_IOCTL_LIST_SECRETS_NR] = BIT_UVC_CMD_LIST_SECRETS,
+ [UVIO_IOCTL_LOCK_SECRETS_NR] = BIT_UVC_CMD_LOCK_SECRETS,
};

static_assert(ARRAY_SIZE(ioctl_nr_to_uvc_bit) == UVIO_IOCTL_NUM_IOCTLS);
@@ -340,6 +341,41 @@ static int uvio_list_secrets(struct uvio_ioctl_cb *uv_ioctl)
return ret;
}

+/** uvio_lock_secrets() - perform a Lock Secret Store UVC
+ * @uv_ioctl: ioctl control block
+ *
+ * uvio_lock_secrets() performs the Lock Secret Store Ultravisor Call. It
+ * performs the UV-call and copies the return codes to the ioctl control block.
+ * After this call was dispatched successfully every following Add Secret UVC
+ * and Lock Secrets UVC will fail with return code 0x102.
+ *
+ * The argument address and size must be 0.
+ *
+ * If the Lock Secrets 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_lock_secrets(struct uvio_ioctl_cb *ioctl)
+{
+ struct uv_cb_nodata uvcb = {
+ .header.len = sizeof(uvcb),
+ .header.cmd = UVC_CMD_LOCK_SECRETS,
+ };
+
+ if (ioctl->argument_addr || ioctl->argument_len)
+ return -EINVAL;
+
+ uv_call(0, (u64)&uvcb);
+ ioctl->uv_rc = uvcb.header.rc;
+ ioctl->uv_rrc = uvcb.header.rrc;
+
+ return 0;
+}
+
static int uvio_copy_and_check_ioctl(struct uvio_ioctl_cb *ioctl, void __user *argp,
unsigned long cmd)
{
@@ -390,6 +426,9 @@ static long uvio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
case UVIO_IOCTL_LIST_SECRETS_NR:
ret = uvio_list_secrets(&uv_ioctl);
break;
+ case UVIO_IOCTL_LOCK_SECRETS_NR:
+ ret = uvio_lock_secrets(&uv_ioctl);
+ break;
default:
ret = -ENOIOCTLCMD;
break;
--
2.40.1


2023-06-15 10:17:26

by Steffen Eiden

[permalink] [raw]
Subject: [PATCH v5 3/7] s390/uvdevice: Add 'Add Secret' UVC

Userspace can call the Add Secret Ultravisor Call using IOCTLs on the
uvdevice. The Add Secret UV call sends an encrypted and
cryptographically verified request to the Ultravisor. The request
inserts a protected guest's secret into the Ultravisor for later use.

The uvdevice is merely transporting the request from userspace to the
Ultravisor. It's neither checking nor manipulating the request data.

Signed-off-by: Steffen Eiden <[email protected]>
Reviewed-by: Janosch Frank <[email protected]>
---
arch/s390/include/asm/uv.h | 14 ++++++
arch/s390/include/uapi/asm/uvdevice.h | 4 ++
drivers/s390/char/uvdevice.c | 63 +++++++++++++++++++++++++++
3 files changed, 81 insertions(+)

diff --git a/arch/s390/include/asm/uv.h b/arch/s390/include/asm/uv.h
index 96939bd11d65..99bda8a9afde 100644
--- a/arch/s390/include/asm/uv.h
+++ b/arch/s390/include/asm/uv.h
@@ -58,6 +58,7 @@
#define UVC_CMD_SET_SHARED_ACCESS 0x1000
#define UVC_CMD_REMOVE_SHARED_ACCESS 0x1001
#define UVC_CMD_RETR_ATTEST 0x1020
+#define UVC_CMD_ADD_SECRET 0x1031

/* Bits in installed uv calls */
enum uv_cmds_inst {
@@ -88,6 +89,7 @@ enum uv_cmds_inst {
BIT_UVC_CMD_DUMP_CPU = 26,
BIT_UVC_CMD_DUMP_COMPLETE = 27,
BIT_UVC_CMD_RETR_ATTEST = 28,
+ BIT_UVC_CMD_ADD_SECRET = 29,
};

enum uv_feat_ind {
@@ -292,6 +294,18 @@ struct uv_cb_dump_complete {
u64 reserved30[5];
} __packed __aligned(8);

+/*
+ * A common UV call struct for pv guests that contains a single address
+ * Examples:
+ * Add Secret
+ */
+struct uv_cb_guest_addr {
+ struct uv_cb_header header;
+ u64 reserved08[3];
+ u64 addr;
+ u64 reserved28[4];
+} __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
index 9d9b684836c2..e77410226598 100644
--- a/arch/s390/include/uapi/asm/uvdevice.h
+++ b/arch/s390/include/uapi/asm/uvdevice.h
@@ -69,6 +69,7 @@ struct uvio_uvdev_info {
#define UVIO_ATT_ARCB_MAX_LEN 0x100000
#define UVIO_ATT_MEASUREMENT_MAX_LEN 0x8000
#define UVIO_ATT_ADDITIONAL_MAX_LEN 0x8000
+#define UVIO_ADD_SECRET_MAX_LEN 0x100000

#define UVIO_DEVICE_NAME "uv"
#define UVIO_TYPE_UVC 'u'
@@ -76,6 +77,7 @@ struct uvio_uvdev_info {
enum UVIO_IOCTL_NR {
UVIO_IOCTL_UVDEV_INFO_NR = 0x00,
UVIO_IOCTL_ATT_NR,
+ UVIO_IOCTL_ADD_SECRET_NR,
/* must be the last entry */
UVIO_IOCTL_NUM_IOCTLS
};
@@ -83,9 +85,11 @@ enum UVIO_IOCTL_NR {
#define UVIO_IOCTL(nr) _IOWR(UVIO_TYPE_UVC, nr, struct uvio_ioctl_cb)
#define UVIO_IOCTL_UVDEV_INFO UVIO_IOCTL(UVIO_IOCTL_UVDEV_INFO_NR)
#define UVIO_IOCTL_ATT UVIO_IOCTL(UVIO_IOCTL_ATT_NR)
+#define UVIO_IOCTL_ADD_SECRET UVIO_IOCTL(UVIO_IOCTL_ADD_SECRET_NR)

#define UVIO_SUPP_CALL(nr) (1ULL << (nr))
#define UVIO_SUPP_UDEV_INFO UVIO_SUPP_CALL(UVIO_IOCTL_UDEV_INFO_NR)
#define UVIO_SUPP_ATT UVIO_SUPP_CALL(UVIO_IOCTL_ATT_NR)
+#define UVIO_SUPP_ADD_SECRET UVIO_SUPP_CALL(UVIO_IOCTL_ADD_SECRET_NR)

#endif /* __S390_ASM_UVDEVICE_H */
diff --git a/drivers/s390/char/uvdevice.c b/drivers/s390/char/uvdevice.c
index 7d7866be389b..7221e987703a 100644
--- a/drivers/s390/char/uvdevice.c
+++ b/drivers/s390/char/uvdevice.c
@@ -37,6 +37,7 @@
static const u32 ioctl_nr_to_uvc_bit[] __initconst = {
[UVIO_IOCTL_UVDEV_INFO_NR] = BIT_UVIO_INTERNAL,
[UVIO_IOCTL_ATT_NR] = BIT_UVC_CMD_RETR_ATTEST,
+ [UVIO_IOCTL_ADD_SECRET_NR] = BIT_UVC_CMD_ADD_SECRET,
};

static_assert(ARRAY_SIZE(ioctl_nr_to_uvc_bit) == UVIO_IOCTL_NUM_IOCTLS);
@@ -231,6 +232,65 @@ static int uvio_attestation(struct uvio_ioctl_cb *uv_ioctl)
return ret;
}

+/** uvio_add_secret() - perform an Add Secret UVC
+ *
+ * @uv_ioctl: ioctl control block
+ *
+ * uvio_add_secret() performs the Add Secret Ultravisor Call.
+ *
+ * The given userspace argument address and size are verified to be
+ * valid but every other check is made by the Ultravisor
+ * (UV). Therefore UV errors won't result in a negative return
+ * value. The request is then copied to kernelspace, the UV-call is
+ * performed and the results are copied back to userspace.
+ *
+ * The argument has to point to an Add Secret Request Control Block
+ * which is an encrypted and cryptographically verified request that
+ * inserts a protected guest's secrets into the Ultravisor for later
+ * use.
+ *
+ * If the Add Secret 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_add_secret(struct uvio_ioctl_cb *uv_ioctl)
+{
+ void __user *user_buf_arg = (void __user *)uv_ioctl->argument_addr;
+ struct uv_cb_guest_addr uvcb = {
+ .header.len = sizeof(uvcb),
+ .header.cmd = UVC_CMD_ADD_SECRET,
+ };
+ void *asrcb = NULL;
+ int ret;
+
+ if (uv_ioctl->argument_len > UVIO_ADD_SECRET_MAX_LEN)
+ return -EINVAL;
+ if (uv_ioctl->argument_len == 0)
+ return -EINVAL;
+
+ asrcb = kvzalloc(uv_ioctl->argument_len, GFP_KERNEL);
+ if (!asrcb)
+ return -ENOMEM;
+
+ ret = -EFAULT;
+ if (copy_from_user(asrcb, user_buf_arg, uv_ioctl->argument_len))
+ goto out;
+
+ ret = 0;
+ uvcb.addr = (u64)asrcb;
+ uv_call_sched(0, (u64)&uvcb);
+ uv_ioctl->uv_rc = uvcb.header.rc;
+ uv_ioctl->uv_rrc = uvcb.header.rrc;
+
+out:
+ kvfree(asrcb);
+ return ret;
+}
+
static int uvio_copy_and_check_ioctl(struct uvio_ioctl_cb *ioctl, void __user *argp,
unsigned long cmd)
{
@@ -275,6 +335,9 @@ static long uvio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
case UVIO_IOCTL_ATT_NR:
ret = uvio_attestation(&uv_ioctl);
break;
+ case UVIO_IOCTL_ADD_SECRET_NR:
+ ret = uvio_add_secret(&uv_ioctl);
+ break;
default:
ret = -ENOIOCTLCMD;
break;
--
2.40.1


2023-06-15 10:17:51

by Steffen Eiden

[permalink] [raw]
Subject: [PATCH v5 1/7] s390/uv: Always export uv_info

KVM needs the struct's values to be able to provide PV support.

The uvdevice is currently guest only and will need the struct's values
for call support checking and potential future expansions.

As uv.c is only compiled with CONFIG_PGSTE or
CONFIG_PROTECTED_VIRTUALIZATION_GUEST we don't need a second check in
the code. Users of uv_info will need to fence for these two config
options for the time being.

Signed-off-by: Steffen Eiden <[email protected]>
---
arch/s390/kernel/uv.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
index 4ada621a2c46..5da3879001bb 100644
--- a/arch/s390/kernel/uv.c
+++ b/arch/s390/kernel/uv.c
@@ -23,12 +23,20 @@
int __bootdata_preserved(prot_virt_guest);
#endif

+/*
+ * uv_info contains both host and guest information but it's currently only
+ * expected to be used within modules if it's the KVM module or for
+ * any PV guest module.
+ *
+ * The kernel itself will write these values once in uv_query_info()
+ * and then make some of them readable via a sysfs interface.
+ */
struct uv_info __bootdata_preserved(uv_info);
+EXPORT_SYMBOL(uv_info);

#if IS_ENABLED(CONFIG_KVM)
int __bootdata_preserved(prot_virt_host);
EXPORT_SYMBOL(prot_virt_host);
-EXPORT_SYMBOL(uv_info);

static int __init uv_init(phys_addr_t stor_base, unsigned long stor_len)
{
--
2.40.1


2023-06-15 10:23:05

by Steffen Eiden

[permalink] [raw]
Subject: [PATCH v5 4/7] s390/uvdevice: Add 'List Secrets' UVC

Userspace can call the List Secrets Ultravisor Call
using IOCTLs on the uvdevice. The List Secrets UV call lists the
identifier of the secrets in the UV secret store.

The uvdevice is merely transporting the request from userspace to
Ultravisor. It's neither checking nor manipulating the request or
response data.

Signed-off-by: Steffen Eiden <[email protected]>
Reviewed-by: Janosch Frank <[email protected]>
---
arch/s390/include/asm/uv.h | 3 ++
arch/s390/include/uapi/asm/uvdevice.h | 4 +++
drivers/s390/char/uvdevice.c | 52 +++++++++++++++++++++++++++
3 files changed, 59 insertions(+)

diff --git a/arch/s390/include/asm/uv.h b/arch/s390/include/asm/uv.h
index 99bda8a9afde..eeb945a7c80e 100644
--- a/arch/s390/include/asm/uv.h
+++ b/arch/s390/include/asm/uv.h
@@ -59,6 +59,7 @@
#define UVC_CMD_REMOVE_SHARED_ACCESS 0x1001
#define UVC_CMD_RETR_ATTEST 0x1020
#define UVC_CMD_ADD_SECRET 0x1031
+#define UVC_CMD_LIST_SECRETS 0x1033

/* Bits in installed uv calls */
enum uv_cmds_inst {
@@ -90,6 +91,7 @@ enum uv_cmds_inst {
BIT_UVC_CMD_DUMP_COMPLETE = 27,
BIT_UVC_CMD_RETR_ATTEST = 28,
BIT_UVC_CMD_ADD_SECRET = 29,
+ BIT_UVC_CMD_LIST_SECRETS = 30,
};

enum uv_feat_ind {
@@ -298,6 +300,7 @@ struct uv_cb_dump_complete {
* A common UV call struct for pv guests that contains a single address
* Examples:
* Add Secret
+ * List Secrets
*/
struct uv_cb_guest_addr {
struct uv_cb_header header;
diff --git a/arch/s390/include/uapi/asm/uvdevice.h b/arch/s390/include/uapi/asm/uvdevice.h
index e77410226598..76045da44868 100644
--- a/arch/s390/include/uapi/asm/uvdevice.h
+++ b/arch/s390/include/uapi/asm/uvdevice.h
@@ -70,6 +70,7 @@ struct uvio_uvdev_info {
#define UVIO_ATT_MEASUREMENT_MAX_LEN 0x8000
#define UVIO_ATT_ADDITIONAL_MAX_LEN 0x8000
#define UVIO_ADD_SECRET_MAX_LEN 0x100000
+#define UVIO_LIST_SECRETS_LEN 0x1000

#define UVIO_DEVICE_NAME "uv"
#define UVIO_TYPE_UVC 'u'
@@ -78,6 +79,7 @@ enum UVIO_IOCTL_NR {
UVIO_IOCTL_UVDEV_INFO_NR = 0x00,
UVIO_IOCTL_ATT_NR,
UVIO_IOCTL_ADD_SECRET_NR,
+ UVIO_IOCTL_LIST_SECRETS_NR,
/* must be the last entry */
UVIO_IOCTL_NUM_IOCTLS
};
@@ -86,10 +88,12 @@ enum UVIO_IOCTL_NR {
#define UVIO_IOCTL_UVDEV_INFO UVIO_IOCTL(UVIO_IOCTL_UVDEV_INFO_NR)
#define UVIO_IOCTL_ATT UVIO_IOCTL(UVIO_IOCTL_ATT_NR)
#define UVIO_IOCTL_ADD_SECRET UVIO_IOCTL(UVIO_IOCTL_ADD_SECRET_NR)
+#define UVIO_IOCTL_LIST_SECRETS UVIO_IOCTL(UVIO_IOCTL_LIST_SECRETS_NR)

#define UVIO_SUPP_CALL(nr) (1ULL << (nr))
#define UVIO_SUPP_UDEV_INFO UVIO_SUPP_CALL(UVIO_IOCTL_UDEV_INFO_NR)
#define UVIO_SUPP_ATT UVIO_SUPP_CALL(UVIO_IOCTL_ATT_NR)
#define UVIO_SUPP_ADD_SECRET UVIO_SUPP_CALL(UVIO_IOCTL_ADD_SECRET_NR)
+#define UVIO_SUPP_LIST_SECRETS UVIO_SUPP_CALL(UVIO_IOCTL_LIST_SECRETS_NR)

#endif /* __S390_ASM_UVDEVICE_H */
diff --git a/drivers/s390/char/uvdevice.c b/drivers/s390/char/uvdevice.c
index 7221e987703a..70502c4ec290 100644
--- a/drivers/s390/char/uvdevice.c
+++ b/drivers/s390/char/uvdevice.c
@@ -38,6 +38,7 @@ static const u32 ioctl_nr_to_uvc_bit[] __initconst = {
[UVIO_IOCTL_UVDEV_INFO_NR] = BIT_UVIO_INTERNAL,
[UVIO_IOCTL_ATT_NR] = BIT_UVC_CMD_RETR_ATTEST,
[UVIO_IOCTL_ADD_SECRET_NR] = BIT_UVC_CMD_ADD_SECRET,
+ [UVIO_IOCTL_LIST_SECRETS_NR] = BIT_UVC_CMD_LIST_SECRETS,
};

static_assert(ARRAY_SIZE(ioctl_nr_to_uvc_bit) == UVIO_IOCTL_NUM_IOCTLS);
@@ -291,6 +292,54 @@ static int uvio_add_secret(struct uvio_ioctl_cb *uv_ioctl)
return ret;
}

+/** uvio_list_secrets() - perform a List Secret UVC
+ * @uv_ioctl: ioctl control block
+ *
+ * uvio_list_secrets() performs the List Secret Ultravisor Call. It verifies
+ * that the given userspace argument address is valid and its size is sane.
+ * Every other check is made by the Ultravisor (UV) and won't result in a
+ * negative return value. It builds the request, performs the UV-call, and
+ * copies the result to userspace.
+ *
+ * The argument specifies the location for the result of the UV-Call.
+ *
+ * If the List Secrets 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_list_secrets(struct uvio_ioctl_cb *uv_ioctl)
+{
+ void __user *user_buf_arg = (void __user *)uv_ioctl->argument_addr;
+ struct uv_cb_guest_addr uvcb = {
+ .header.len = sizeof(uvcb),
+ .header.cmd = UVC_CMD_LIST_SECRETS,
+ };
+ void *secrets = NULL;
+ int ret = 0;
+
+ if (uv_ioctl->argument_len != UVIO_LIST_SECRETS_LEN)
+ return -EINVAL;
+
+ secrets = kvzalloc(UVIO_LIST_SECRETS_LEN, GFP_KERNEL);
+ if (!secrets)
+ return -ENOMEM;
+
+ uvcb.addr = (u64)secrets;
+ uv_call_sched(0, (u64)&uvcb);
+ uv_ioctl->uv_rc = uvcb.header.rc;
+ uv_ioctl->uv_rrc = uvcb.header.rrc;
+
+ if (copy_to_user(user_buf_arg, secrets, UVIO_LIST_SECRETS_LEN))
+ ret = -EFAULT;
+
+ kvfree(secrets);
+ return ret;
+}
+
static int uvio_copy_and_check_ioctl(struct uvio_ioctl_cb *ioctl, void __user *argp,
unsigned long cmd)
{
@@ -338,6 +387,9 @@ static long uvio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
case UVIO_IOCTL_ADD_SECRET_NR:
ret = uvio_add_secret(&uv_ioctl);
break;
+ case UVIO_IOCTL_LIST_SECRETS_NR:
+ ret = uvio_list_secrets(&uv_ioctl);
+ break;
default:
ret = -ENOIOCTLCMD;
break;
--
2.40.1


2023-06-15 10:29:45

by Steffen Eiden

[permalink] [raw]
Subject: [PATCH v5 7/7] s390/uv: Update query for secret-UVCs

Update the query struct such that secret-UVC related
information can be parsed.
Add sysfs files for these new values.

'supp_add_secret_req_ver' notes the supported versions for the
Add Secret UVC. Bit 0 indicates that version 0x100 is supported,
bit 1 indicates 0x200, and so on.

'supp_add_secret_pcf' notes the supported plaintext flags for
the Add Secret UVC.

'supp_secret_types' notes the supported types of secrets.
Bit 0 indicates secret type 1, bit 1 indicates type 2, and so on.

'max_secrets' notes the maximum amount of secrets the secret store can
store per pv guest.

Signed-off-by: Steffen Eiden <[email protected]>
Reviewed-by: Janosch Frank <[email protected]>
---
arch/s390/boot/uv.c | 4 ++++
arch/s390/include/asm/uv.h | 13 +++++++++++--
arch/s390/kernel/uv.c | 40 ++++++++++++++++++++++++++++++++++++++
3 files changed, 55 insertions(+), 2 deletions(-)

diff --git a/arch/s390/boot/uv.c b/arch/s390/boot/uv.c
index 0a077c0a2056..1e66d2cbb096 100644
--- a/arch/s390/boot/uv.c
+++ b/arch/s390/boot/uv.c
@@ -47,6 +47,10 @@ void uv_query_info(void)
uv_info.conf_dump_finalize_len = uvcb.conf_dump_finalize_len;
uv_info.supp_att_req_hdr_ver = uvcb.supp_att_req_hdr_ver;
uv_info.supp_att_pflags = uvcb.supp_att_pflags;
+ uv_info.supp_add_secret_req_ver = uvcb.supp_add_secret_req_ver;
+ uv_info.supp_add_secret_pcf = uvcb.supp_add_secret_pcf;
+ uv_info.supp_secret_types = uvcb.supp_secret_types;
+ uv_info.max_secrets = uvcb.max_secrets;
}

#ifdef CONFIG_PROTECTED_VIRTUALIZATION_GUEST
diff --git a/arch/s390/include/asm/uv.h b/arch/s390/include/asm/uv.h
index 1d47b3e40be8..d2cd42bb2c26 100644
--- a/arch/s390/include/asm/uv.h
+++ b/arch/s390/include/asm/uv.h
@@ -123,7 +123,7 @@ struct uv_cb_qui {
u32 reserved70[3]; /* 0x0070 */
u32 max_num_sec_conf; /* 0x007c */
u64 max_guest_stor_addr; /* 0x0080 */
- u8 reserved88[158 - 136]; /* 0x0088 */
+ u8 reserved88[0x9e - 0x88]; /* 0x0088 */
u16 max_guest_cpu_id; /* 0x009e */
u64 uv_feature_indications; /* 0x00a0 */
u64 reserveda8; /* 0x00a8 */
@@ -135,7 +135,12 @@ struct uv_cb_qui {
u64 reservedd8; /* 0x00d8 */
u64 supp_att_req_hdr_ver; /* 0x00e0 */
u64 supp_att_pflags; /* 0x00e8 */
- u8 reservedf0[256 - 240]; /* 0x00f0 */
+ u64 reservedf0; /* 0x00f0 */
+ u64 supp_add_secret_req_ver; /* 0x00f8 */
+ u64 supp_add_secret_pcf; /* 0x0100 */
+ u64 supp_secret_types; /* 0x0180 */
+ u16 max_secrets; /* 0x0110 */
+ u8 reserved112[0x120 - 0x112]; /* 0x0112 */
} __packed __aligned(8);

/* Initialize Ultravisor */
@@ -384,6 +389,10 @@ struct uv_info {
unsigned long conf_dump_finalize_len;
unsigned long supp_att_req_hdr_ver;
unsigned long supp_att_pflags;
+ unsigned long supp_add_secret_req_ver;
+ unsigned long supp_add_secret_pcf;
+ unsigned long supp_secret_types;
+ unsigned short max_secrets;
};

extern struct uv_info uv_info;
diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
index b8721b67a50d..6a0153289ace 100644
--- a/arch/s390/kernel/uv.c
+++ b/arch/s390/kernel/uv.c
@@ -580,6 +580,42 @@ static ssize_t uv_query_supp_att_pflags(struct kobject *kobj,
static struct kobj_attribute uv_query_supp_att_pflags_attr =
__ATTR(supp_att_pflags, 0444, uv_query_supp_att_pflags, NULL);

+static ssize_t uv_query_supp_add_secret_req_ver(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ return sysfs_emit(buf, "%lx\n", uv_info.supp_add_secret_req_ver);
+}
+
+static struct kobj_attribute uv_query_supp_add_secret_req_ver_attr =
+ __ATTR(supp_add_secret_req_ver, 0444, uv_query_supp_add_secret_req_ver, NULL);
+
+static ssize_t uv_query_supp_add_secret_pcf(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ return sysfs_emit(buf, "%lx\n", uv_info.supp_add_secret_pcf);
+}
+
+static struct kobj_attribute uv_query_supp_add_secret_pcf_attr =
+ __ATTR(supp_add_secret_pcf, 0444, uv_query_supp_add_secret_pcf, NULL);
+
+static ssize_t uv_query_supp_secret_types(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ return sysfs_emit(buf, "%lx\n", uv_info.supp_secret_types);
+}
+
+static struct kobj_attribute uv_query_supp_secret_types_attr =
+ __ATTR(supp_secret_types, 0444, uv_query_supp_secret_types, NULL);
+
+static ssize_t uv_query_max_secrets(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ return sysfs_emit(buf, "%d\n", uv_info.max_secrets);
+}
+
+static struct kobj_attribute uv_query_max_secrets_attr =
+ __ATTR(max_secrets, 0444, uv_query_max_secrets, NULL);
+
static struct attribute *uv_query_attrs[] = {
&uv_query_facilities_attr.attr,
&uv_query_feature_indications_attr.attr,
@@ -593,6 +629,10 @@ static struct attribute *uv_query_attrs[] = {
&uv_query_dump_cpu_len_attr.attr,
&uv_query_supp_att_req_hdr_ver_attr.attr,
&uv_query_supp_att_pflags_attr.attr,
+ &uv_query_supp_add_secret_req_ver_attr.attr,
+ &uv_query_supp_add_secret_pcf_attr.attr,
+ &uv_query_supp_secret_types_attr.attr,
+ &uv_query_max_secrets_attr.attr,
NULL,
};

--
2.40.1


2023-06-15 10:30:19

by Steffen Eiden

[permalink] [raw]
Subject: [PATCH v5 6/7] s390/uv: replace scnprintf with sysfs_emit

Replace scnprintf(page, PAGE_SIZE, ...) with the page size aware
sysfs_emit(buf, ...) which adds some sanity checks.

Signed-off-by: Steffen Eiden <[email protected]>
Reviewed-by: Janosch Frank <[email protected]>
---
arch/s390/kernel/uv.c | 58 +++++++++++++++++++------------------------
1 file changed, 26 insertions(+), 32 deletions(-)

diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
index 5da3879001bb..b8721b67a50d 100644
--- a/arch/s390/kernel/uv.c
+++ b/arch/s390/kernel/uv.c
@@ -469,13 +469,13 @@ EXPORT_SYMBOL_GPL(arch_make_page_accessible);

#if defined(CONFIG_PROTECTED_VIRTUALIZATION_GUEST) || IS_ENABLED(CONFIG_KVM)
static ssize_t uv_query_facilities(struct kobject *kobj,
- struct kobj_attribute *attr, char *page)
+ struct kobj_attribute *attr, char *buf)
{
- return scnprintf(page, PAGE_SIZE, "%lx\n%lx\n%lx\n%lx\n",
- uv_info.inst_calls_list[0],
- uv_info.inst_calls_list[1],
- uv_info.inst_calls_list[2],
- uv_info.inst_calls_list[3]);
+ return sysfs_emit(buf, "%lx\n%lx\n%lx\n%lx\n",
+ uv_info.inst_calls_list[0],
+ uv_info.inst_calls_list[1],
+ uv_info.inst_calls_list[2],
+ uv_info.inst_calls_list[3]);
}

static struct kobj_attribute uv_query_facilities_attr =
@@ -500,30 +500,27 @@ static struct kobj_attribute uv_query_supp_se_hdr_pcf_attr =
__ATTR(supp_se_hdr_pcf, 0444, uv_query_supp_se_hdr_pcf, NULL);

static ssize_t uv_query_dump_cpu_len(struct kobject *kobj,
- struct kobj_attribute *attr, char *page)
+ struct kobj_attribute *attr, char *buf)
{
- return scnprintf(page, PAGE_SIZE, "%lx\n",
- uv_info.guest_cpu_stor_len);
+ return sysfs_emit(buf, "%lx\n", uv_info.guest_cpu_stor_len);
}

static struct kobj_attribute uv_query_dump_cpu_len_attr =
__ATTR(uv_query_dump_cpu_len, 0444, uv_query_dump_cpu_len, NULL);

static ssize_t uv_query_dump_storage_state_len(struct kobject *kobj,
- struct kobj_attribute *attr, char *page)
+ struct kobj_attribute *attr, char *buf)
{
- return scnprintf(page, PAGE_SIZE, "%lx\n",
- uv_info.conf_dump_storage_state_len);
+ return sysfs_emit(buf, "%lx\n", uv_info.conf_dump_storage_state_len);
}

static struct kobj_attribute uv_query_dump_storage_state_len_attr =
__ATTR(dump_storage_state_len, 0444, uv_query_dump_storage_state_len, NULL);

static ssize_t uv_query_dump_finalize_len(struct kobject *kobj,
- struct kobj_attribute *attr, char *page)
+ struct kobj_attribute *attr, char *buf)
{
- return scnprintf(page, PAGE_SIZE, "%lx\n",
- uv_info.conf_dump_finalize_len);
+ return sysfs_emit(buf, "%lx\n", uv_info.conf_dump_finalize_len);
}

static struct kobj_attribute uv_query_dump_finalize_len_attr =
@@ -539,48 +536,45 @@ static struct kobj_attribute uv_query_feature_indications_attr =
__ATTR(feature_indications, 0444, uv_query_feature_indications, NULL);

static ssize_t uv_query_max_guest_cpus(struct kobject *kobj,
- struct kobj_attribute *attr, char *page)
+ struct kobj_attribute *attr, char *buf)
{
- return scnprintf(page, PAGE_SIZE, "%d\n",
- uv_info.max_guest_cpu_id + 1);
+ return sysfs_emit(buf, "%d\n", uv_info.max_guest_cpu_id + 1);
}

static struct kobj_attribute uv_query_max_guest_cpus_attr =
__ATTR(max_cpus, 0444, uv_query_max_guest_cpus, NULL);

static ssize_t uv_query_max_guest_vms(struct kobject *kobj,
- struct kobj_attribute *attr, char *page)
+ struct kobj_attribute *attr, char *buf)
{
- return scnprintf(page, PAGE_SIZE, "%d\n",
- uv_info.max_num_sec_conf);
+ return sysfs_emit(buf, "%d\n", uv_info.max_num_sec_conf);
}

static struct kobj_attribute uv_query_max_guest_vms_attr =
__ATTR(max_guests, 0444, uv_query_max_guest_vms, NULL);

static ssize_t uv_query_max_guest_addr(struct kobject *kobj,
- struct kobj_attribute *attr, char *page)
+ struct kobj_attribute *attr, char *buf)
{
- return scnprintf(page, PAGE_SIZE, "%lx\n",
- uv_info.max_sec_stor_addr);
+ return sysfs_emit(buf, "%lx\n", uv_info.max_sec_stor_addr);
}

static struct kobj_attribute uv_query_max_guest_addr_attr =
__ATTR(max_address, 0444, uv_query_max_guest_addr, NULL);

static ssize_t uv_query_supp_att_req_hdr_ver(struct kobject *kobj,
- struct kobj_attribute *attr, char *page)
+ struct kobj_attribute *attr, char *buf)
{
- return scnprintf(page, PAGE_SIZE, "%lx\n", uv_info.supp_att_req_hdr_ver);
+ return sysfs_emit(buf, "%lx\n", uv_info.supp_att_req_hdr_ver);
}

static struct kobj_attribute uv_query_supp_att_req_hdr_ver_attr =
__ATTR(supp_att_req_hdr_ver, 0444, uv_query_supp_att_req_hdr_ver, NULL);

static ssize_t uv_query_supp_att_pflags(struct kobject *kobj,
- struct kobj_attribute *attr, char *page)
+ struct kobj_attribute *attr, char *buf)
{
- return scnprintf(page, PAGE_SIZE, "%lx\n", uv_info.supp_att_pflags);
+ return sysfs_emit(buf, "%lx\n", uv_info.supp_att_pflags);
}

static struct kobj_attribute uv_query_supp_att_pflags_attr =
@@ -607,18 +601,18 @@ static struct attribute_group uv_query_attr_group = {
};

static ssize_t uv_is_prot_virt_guest(struct kobject *kobj,
- struct kobj_attribute *attr, char *page)
+ struct kobj_attribute *attr, char *buf)
{
int val = 0;

#ifdef CONFIG_PROTECTED_VIRTUALIZATION_GUEST
val = prot_virt_guest;
#endif
- return scnprintf(page, PAGE_SIZE, "%d\n", val);
+ return sysfs_emit(buf, "%d\n", val);
}

static ssize_t uv_is_prot_virt_host(struct kobject *kobj,
- struct kobj_attribute *attr, char *page)
+ struct kobj_attribute *attr, char *buf)
{
int val = 0;

@@ -626,7 +620,7 @@ static ssize_t uv_is_prot_virt_host(struct kobject *kobj,
val = prot_virt_host;
#endif

- return scnprintf(page, PAGE_SIZE, "%d\n", val);
+ return sysfs_emit(buf, "%d\n", val);
}

static struct kobj_attribute uv_prot_virt_guest =
--
2.40.1


2023-06-16 09:02:19

by Janosch Frank

[permalink] [raw]
Subject: Re: [PATCH v5 1/7] s390/uv: Always export uv_info

On 6/15/23 12:05, Steffen Eiden wrote:
> KVM needs the struct's values to be able to provide PV support.
>
> The uvdevice is currently guest only and will need the struct's values
> for call support checking and potential future expansions.
>
> As uv.c is only compiled with CONFIG_PGSTE or
> CONFIG_PROTECTED_VIRTUALIZATION_GUEST we don't need a second check in
> the code. Users of uv_info will need to fence for these two config
> options for the time being.
>
> Signed-off-by: Steffen Eiden <[email protected]>
>
Reviewed-by: Janosch Frank <[email protected]>

In the long term we'll remove the config checks and always compile uv.o
in kernel/ and boot/ so we won't be running in these issues again.