PowerPC FW introduced HVPIPE RTAS calls such as
ibm,send-hvpipe-msg and ibm,receive-hvpipe-msg for the user space
to exchange information with different sources such as Hardware
Management Consoles (HMC).
HVPIPE_IOC_CREATE_HANDLE is defined to use /dev/papr-hvpipe
interface for ibm,send-hvpipe-msg and ibm,receive-hvpipe-msg
RTAS calls.
Also defined papr_hvpipe_hdr which will added in the payload
that is passed between the kernel and the user space.
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Tested-by: Shashank MS <shashank.gowda@in.ibm.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250909084402.1488456-2-haren@linux.ibm.com
__ASSEMBLY__ is only defined by the Makefile of the kernel, so
this is not really useful for uapi headers (unless the userspace
Makefile defines it, too). Let's switch to __ASSEMBLER__ which
gets set automatically by the compiler when compiling assembler
code.
This is a completely mechanical patch (done with a simple "sed -i"
statement).
Acked-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250801082007.32904-2-thuth@redhat.com
Since termio interface is now obsolete, include/uapi/asm/ioctls.h
has some constant macros referring to "struct termio", this caused
build failure at userspace.
In file included from /usr/include/asm/ioctl.h:12,
from /usr/include/asm/ioctls.h:5,
from tst-ioctls.c:3:
tst-ioctls.c: In function 'get_TCGETA':
tst-ioctls.c:12:10: error: invalid application of 'sizeof' to incomplete type 'struct termio'
12 | return TCGETA;
| ^~~~~~
Even though termios.h provides "struct termio", trying to juggle definitions around to
make it compile could introduce regressions. So better to open code it.
Reported-by: Tulio Magno <tuliom@ascii.art.br>
Suggested-by: Nicholas Piggin <npiggin@gmail.com>
Tested-by: Justin M. Forbes <jforbes@fedoraproject.org>
Reviewed-by: Michael Ellerman <mpe@ellerman.id.au>
Closes: https://lore.kernel.org/linuxppc-dev/8734dji5wl.fsf@ascii.art.br/
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250517142237.156665-1-maddy@linux.ibm.com
The RTAS call ibm,physical-attestation is used to retrieve
information about the trusted boot state of the firmware and
hypervisor on the system, and also Trusted Platform Modules (TPM)
data if the system is TCG 2.0 compliant.
This RTAS interface expects the caller to define different command
structs such as RetrieveTPMLog, RetrievePlatformCertificat and etc,
in a work area with a maximum size of 4K bytes and the response
buffer will be returned in the same work area.
The current implementation of this RTAS function is in the user
space but allocation of the work area is restricted with the system
lockdown. So this patch implements this RTAS function in the kernel
and expose to the user space with open/ioctl/read interfaces.
PAPR (2.13+ 21.3 ibm,physical-attestation) defines RTAS function:
- Pass the command struct to obtain the response buffer for the
specific command.
- This RTAS function is sequence RTAS call and has to issue RTAS
call multiple times to get the complete response buffer (max 64K).
The hypervisor expects the first RTAS call with the sequence 1 and
the subsequent calls with the sequence number returned from the
previous calls.
Expose these interfaces to user space with a
/dev/papr-physical-attestation character device using the following
programming model:
int devfd = open("/dev/papr-physical-attestation");
int fd = ioctl(devfd, PAPR_PHY_ATTEST_IOC_HANDLE,
struct papr_phy_attest_io_block);
- The user space defines the command struct and requests the
response for any command.
- Obtain the complete response buffer and returned the buffer as
blob to the command specific FD.
size = read(fd, buf, len);
- Can retrieve the response buffer once or multiple times until the
end of BLOB buffer.
Implemented this new kernel ABI support in librtas library for
system lockdown
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250416225743.596462-8-haren@linux.ibm.com
ibm,platform-dump RTAS call in combination with writable mapping
/dev/mem is issued to collect platform dump from the hypervisor
and may need multiple calls to get the complete dump. The current
implementation uses rtas_platform_dump() API provided by librtas
library to issue these RTAS calls. But /dev/mem access by the
user space is prohibited under system lockdown.
The solution should be to restrict access to RTAS function in user
space and provide kernel interfaces to collect dump. This patch
adds papr-platform-dump character driver and expose standard
interfaces such as open / ioctl/ read to user space in ways that
are compatible with lockdown.
PAPR (7.3.3.4.1 ibm,platform-dump) provides a method to obtain
the complete dump:
- Each dump will be identified by ID called dump tag.
- A sequence of RTAS calls have to be issued until retrieve the
complete dump. The hypervisor expects the first RTAS call with
the sequence 0 and the subsequent calls with the sequence
number returned from the previous calls.
- The hypervisor returns "dump complete" status once the complete
dump is retrieved. But expects one more RTAS call from the
partition with the NULL buffer to invalidate dump which means
the dump will be removed in the hypervisor.
- Sequence of calls are allowed with different dump IDs at the
same time but not with the same dump ID.
Expose these interfaces to user space with a /dev/papr-platform-dump
character device using the following programming model:
int devfd = open("/dev/papr-platform-dump", O_RDONLY);
int fd = ioctl(devfd,PAPR_PLATFORM_DUMP_IOC_CREATE_HANDLE, &dump_id)
- Restrict user space to access with the same dump ID.
Typically we do not expect user space requests the dump
again for the same dump ID.
char *buf = malloc(size);
length = read(fd, buf, size);
- size should be minimum 1K based on PAPR and <= 4K based
on RTAS work area size. It will be restrict to RTAS work
area size. Using 4K work area based on the current
implementation in librtas library
- Each read call issue RTAS call to get the data based on
the size requirement and returns bytes returned from the
hypervisor
- If the previous call returns dump complete status, the
next read returns 0 like EOF.
ret = ioctl(PAPR_PLATFORM_DUMP_IOC_INVALIDATE, &dump_id)
- RTAS call with NULL buffer to invalidates the dump.
The read API should use the file descriptor obtained from ioctl
based on dump ID so that gets dump contents for the corresponding
dump ID. Implemented support in librtas (rtas_platform_dump()) for
this new ABI to support system lockdown.
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Tested-by: Sathvika Vasireddy <sv@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250416225743.596462-7-haren@linux.ibm.com
To issue ibm,get-indices, ibm,set-dynamic-indicator and
ibm,get-dynamic-sensor-state in the user space, the RMO buffer is
allocated for the work area which is restricted under system
lockdown. So instead of user space execution, the kernel will
provide /dev/papr-indices interface to execute these RTAS calls.
The user space assigns data in papr_indices_io_block struct
depends on the specific HCALL and passes to the following ioctls:
PAPR_INDICES_IOC_GET: Use for ibm,get-indices. Returns a
get-indices handle fd to read data.
PAPR_DYNAMIC_SENSOR_IOC_GET: Use for ibm,get-dynamic-sensor-state.
Updates the sensor state in
papr_indices_io_block.dynamic_param.state
PAPR_DYNAMIC_INDICATOR_IOC_SET: Use for ibm,set-dynamic-indicator.
Sets the new state for the input
indicator.
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Tested-by: Sathvika Vasireddy <sv@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250416225743.596462-3-haren@linux.ibm.com
Pull powerpc updates from Michael Ellerman:
- Enable BPF Kernel Functions (kfuncs) in the powerpc BPF JIT.
- Allow per-process DEXCR (Dynamic Execution Control Register) settings
via prctl, notably NPHIE which controls hashst/hashchk for ROP
protection.
- Install powerpc selftests in sub-directories. Note this changes the
way run_kselftest.sh needs to be invoked for powerpc selftests.
- Change fadump (Firmware Assisted Dump) to better handle memory
add/remove.
- Add support for passing additional parameters to the fadump kernel.
- Add support for updating the kdump image on CPU/memory add/remove
events.
- Other small features, cleanups and fixes.
Thanks to Andrew Donnellan, Andy Shevchenko, Aneesh Kumar K.V, Arnd
Bergmann, Benjamin Gray, Bjorn Helgaas, Christian Zigotzky, Christophe
Jaillet, Christophe Leroy, Colin Ian King, Cédric Le Goater, Dr. David
Alan Gilbert, Erhard Furtner, Frank Li, GUO Zihua, Ganesh Goudar, Geoff
Levand, Ghanshyam Agrawal, Greg Kurz, Hari Bathini, Joel Stanley, Justin
Stitt, Kunwu Chan, Li Yang, Lidong Zhong, Madhavan Srinivasan, Mahesh
Salgaonkar, Masahiro Yamada, Matthias Schiffer, Naresh Kamboju, Nathan
Chancellor, Nathan Lynch, Naveen N Rao, Nicholas Miehlbradt, Ran Wang,
Randy Dunlap, Ritesh Harjani, Sachin Sant, Shirisha Ganta, Shrikanth
Hegde, Sourabh Jain, Stephen Rothwell, sundar, Thorsten Blum, Vaibhav
Jain, Xiaowei Bao, Yang Li, and Zhao Chenhui.
* tag 'powerpc-6.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (85 commits)
powerpc/fadump: Fix section mismatch warning
powerpc/85xx: fix compile error without CONFIG_CRASH_DUMP
powerpc/fadump: update documentation about bootargs_append
powerpc/fadump: pass additional parameters when fadump is active
powerpc/fadump: setup additional parameters for dump capture kernel
powerpc/pseries/fadump: add support for multiple boot memory regions
selftests/powerpc/dexcr: Fix spelling mistake "predicition" -> "prediction"
KVM: PPC: Book3S HV nestedv2: Fix an error handling path in gs_msg_ops_kvmhv_nestedv2_config_fill_info()
KVM: PPC: Fix documentation for ppc mmu caps
KVM: PPC: code cleanup for kvmppc_book3s_irqprio_deliver
KVM: PPC: Book3S HV nestedv2: Cancel pending DEC exception
powerpc/xmon: Check cpu id in commands "c#", "dp#" and "dx#"
powerpc/code-patching: Use dedicated memory routines for patching
powerpc/code-patching: Test patch_instructions() during boot
powerpc64/kasan: Pass virtual addresses to kasan_init_phys_region()
powerpc: rename SPRN_HID2 define to SPRN_HID2_750FX
powerpc: Fix typos
powerpc/eeh: Fix spelling of the word "auxillary" and update comment
macintosh/ams: Fix unused variable warning
powerpc/Makefile: Remove bits related to the previous use of -mcmodel=large
...
papr_scm and ndtest share common PDSM payload structs like
nd_papr_pdsm_health. Presently these structs are duplicated across
papr_pdsm.h and ndtest.h header files. Since 'ndtest' is essentially
arch independent and can run on platforms other than PPC64, a way
needs to be deviced to avoid redundancy and duplication of PDSM
structs in future.
So the patch proposes moving the PDSM header from arch/powerpc/include-
-/uapi/ to the generic include/uapi/linux directory. Also, there
are some #defines common between papr_scm and ndtest which are not
exported to the user space. So, move them to a header file which
can be shared across ndtest and papr_scm via newly introduced
include/linux/papr_scm.h.
Signed-off-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Suggested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Link: https://lore.kernel.org/r/170638176942.112443.2937254675538057083.stgit@ltcd48-lp2.aus.stglab.ibm.com
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
LoongArch KVM changes for v6.9
* Set reserved bits as zero in CPUCFG.
* Start SW timer only when vcpu is blocking.
* Do not restart SW timer when it is expired.
* Remove unnecessary CSR register saving during enter guest.
Since all architectures (for historical reasons) have to define
struct kvm_guest_debug_arch, and since userspace has to check
KVM_CHECK_EXTENSION(KVM_CAP_SET_GUEST_DEBUG) anyway, there is
no advantage in masking the capability #define itself. Remove
the #define __KVM_HAVE_GUEST_DEBUG from architecture-specific
headers.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
While this in principle breaks the appearance of KVM_PPC_* ioctls on architectures
other than powerpc, this seems unlikely to be a problem considering that there are
already many "struct kvm_ppc_*" definitions in arch/powerpc/include/uapi.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Some PAPR system parameter values are formatted by firmware as
nul-terminated strings (e.g. LPAR name, shared processor attributes).
But the values returned for other parameters, such as processor module
info and TLB block invalidate characteristics, are binary data with
parameter-specific layouts. So char[] isn't the appropriate type for
the general case. Use u8/__u8.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Fixes: 905b9e4878 ("powerpc/pseries/papr-sysparm: Expose character device to user space")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240202-papr-sysparm-ioblock-data-use-u8-v1-1-f5c6c89f65ec@linux.ibm.com
Until now the papr_sysparm APIs have been kernel-internal. But user
space needs access to PAPR system parameters too. The only method
available to user space today to get or set system parameters is using
sys_rtas() and /dev/mem to pass RTAS-addressable buffers between user
space and firmware. This is incompatible with lockdown and should be
deprecated.
So provide an alternative ABI to user space in the form of a
/dev/papr-sysparm character device with just two ioctl commands (get
and set). The data payloads involved are small enough to fit in the
ioctl argument buffer, making the code relatively simple.
Exposing the system parameters through sysfs has been considered but
it would be too awkward:
* The kernel currently does not have to contain an exhaustive list of
defined system parameters. This is a convenient property to maintain
because we don't have to update the kernel whenever a new parameter
is added to PAPR. Exporting a named attribute in sysfs for each
parameter would negate this.
* Some system parameters are text-based and some are not.
* Retrieval of at least one system parameter requires input data,
which a simple read-oriented interface can't support.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231212-papr-sys_rtas-vs-lockdown-v6-11-e9eafd0c8c6c@linux.ibm.com
PowerVM LPARs may retrieve Vital Product Data (VPD) for system
components using the ibm,get-vpd RTAS function.
We can expose this to user space with a /dev/papr-vpd character
device, where the programming model is:
struct papr_location_code plc = { .str = "", }; /* obtain all VPD */
int devfd = open("/dev/papr-vpd", O_RDONLY);
int vpdfd = ioctl(devfd, PAPR_VPD_CREATE_HANDLE, &plc);
size_t size = lseek(vpdfd, 0, SEEK_END);
char *buf = malloc(size);
pread(devfd, buf, size, 0);
When a file descriptor is obtained from ioctl(PAPR_VPD_CREATE_HANDLE),
the file contains the result of a complete ibm,get-vpd sequence. The
file contents are immutable from the POV of user space. To get a new
view of the VPD, the client must create a new handle.
This design choice insulates user space from most of the complexities
that ibm,get-vpd brings:
* ibm,get-vpd must be called more than once to obtain complete
results.
* Only one ibm,get-vpd call sequence should be in progress at a time;
interleaved sequences will disrupt each other. Callers must have a
protocol for serializing their use of the function.
* A call sequence in progress may receive a "VPD changed, try again"
status, requiring the client to abandon the sequence and start
over.
The memory required for the VPD buffers seems acceptable, around 20KB
for all VPD on one of my systems. And the value of the
/rtas/ibm,vpd-size DT property (the estimated maximum size of VPD) is
consistently 300KB across various systems I've checked.
I've implemented support for this new ABI in the rtas_get_vpd()
function in librtas, which the vpdupdate command currently uses to
populate its VPD database. I've verified that an unmodified vpdupdate
binary generates an identical database when using a librtas.so that
prefers the new ABI.
Along with the papr-vpd.h header exposed to user space, this
introduces a common papr-miscdev.h uapi header to share a base ioctl
ID with similar drivers to come.
Tested-by: Michal Suchánek <msuchanek@suse.de>
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231212-papr-sys_rtas-vs-lockdown-v6-9-e9eafd0c8c6c@linux.ibm.com
The HASHKEYR register contains a secret per-process key to enable unique
hashes per process. In general it should not be exposed to userspace
at all and a regular process has no need to know its key.
However, checkpoint restore in userspace (CRIU) functionality requires
that a process be able to set the HASHKEYR of another process, otherwise
existing hashes on the stack would be invalidated by a new random key.
Exposing HASHKEYR in this way also makes it appear in core dumps, which
is a security concern. Multiple threads may share a key, for example
just after a fork() call, where the kernel cannot know if the child is
going to return back along the parent's stack. If such a thread is
coerced into making a core dump, then the HASHKEYR value will be
readable and able to be used against all other threads sharing that key,
effectively undoing any protection offered by hashst/hashchk.
Therefore we expose HASHKEYR to ptrace when CONFIG_CHECKPOINT_RESTORE is
enabled, providing a choice of increased security or migratable ROP
protected processes. This is similar to how ARM exposes its PAC keys.
Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Reviewed-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230616034846.311705-8-bgray@linux.ibm.com
The DEXCR register is of interest when ptracing processes. Currently it
is static, but eventually will be dynamically controllable by a process.
If a process can control its own, then it is useful for it to be
ptrace-able to (e.g., for checkpoint-restore functionality).
It is also relevant to core dumps (the NPHIE aspect in particular),
which use the ptrace mechanism (or is it the other way around?) to
decide what to dump. The HDEXCR is useful here too, as the NPHIE aspect
may be set in the HDEXCR without being set in the DEXCR. Although the
HDEXCR is per-cpu and we don't track it in the task struct (it's useless
in normal operation), it would be difficult to imagine why a hypervisor
would set it to different values within a guest. A hypervisor cannot
safely set NPHIE differently at least, as that would break programs.
Expose a read-only view of the userspace DEXCR and HDEXCR to ptrace.
The HDEXCR is always readonly, and is useful for diagnosing the core
dumps (as the HDEXCR may set NPHIE without the DEXCR setting it).
Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Reviewed-by: Russell Currey <ruscur@russell.cc>
[mpe: Use lower_32_bits() rather than open coding]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230616034846.311705-7-bgray@linux.ibm.com
Build modules using PCREL addressing when CONFIG_PPC_KERNEL_PCREL=y.
- The module loader must handle several new relocation types:
* R_PPC64_REL24_NOTOC is a function call handled like R_PPC_REL24, but
does not restore r2 upon return. The external function call stub is
changed to use pcrel addressing to load the function pointer rather
than based on the module TOC.
* R_PPC64_GOT_PCREL34 is a reference to external data. A GOT table
must be built by hand, because the linker adds this during the final
link (which is not done for kernel modules). The GOT table is built
similarly to the way the external function call stub table is. This
section is called .mygot because .got has a special meaning for the
linker and can become upset.
* R_PPC64_PCREL34 is used for local data addressing, but there is a
special case where the percpu section is moved at load-time to the
percpu area which is out of range of this relocation. This requires
the PCREL34 relocations are converted to use GOT_PCREL34 addressing.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Some coding style & formatting fixups]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230408021752.862660-7-npiggin@gmail.com
Trying to build a .c file that includes <linux/bpf_perf_event.h>:
$ cat test_bpf_headers.c
#include <linux/bpf_perf_event.h>
throws the below error:
/usr/include/linux/bpf_perf_event.h:14:28: error: field ‘regs’ has incomplete type
14 | bpf_user_pt_regs_t regs;
| ^~~~
This is because we typedef bpf_user_pt_regs_t to 'struct user_pt_regs'
in arch/powerpc/include/uaps/asm/bpf_perf_event.h, but 'struct
user_pt_regs' is not exposed to userspace.
Powerpc has both pt_regs and user_pt_regs structures. However, unlike
arm64 and s390, we expose user_pt_regs to userspace as just 'pt_regs'.
As such, we should typedef bpf_user_pt_regs_t to 'struct pt_regs' for
userspace.
Within the kernel though, we want to typedef bpf_user_pt_regs_t to
'struct user_pt_regs'.
Remove arch/powerpc/include/uapi/asm/bpf_perf_event.h so that the
uapi/asm-generic version of the header is exposed to userspace.
Introduce arch/powerpc/include/asm/bpf_perf_event.h so that we can
typedef bpf_user_pt_regs_t to 'struct user_pt_regs' for use within the
kernel.
Note that this was not showing up with the bpf selftest build since
tools/include/uapi/asm/bpf_perf_event.h didn't include the powerpc
variant.
Fixes: a6460b03f9 ("powerpc/bpf: Fix broken uapi for BPF_PROG_TYPE_PERF_EVENT")
Cc: stable@vger.kernel.org # v4.20+
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
[mpe: Use typical naming for header include guard]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220627191119.142867-1-naveen.n.rao@linux.vnet.ibm.com
