Compared to the SNP Guest Request, the "Extended" version adds data pages for
receiving certificates. If not enough pages provided, the HV can report to the
VM how much is needed so the VM can reallocate and repeat.
Commit
ae596615d9 ("virt: sev-guest: Reduce the scope of SNP command mutex")
moved handling of the allocated/desired pages number out of scope of said
mutex and create a possibility for a race (multiple instances trying to
trigger Extended request in a VM) as there is just one instance of
snp_msg_desc per /dev/sev-guest and no locking other than snp_cmd_mutex.
Fix the issue by moving the data blob/size and the GHCB input struct
(snp_req_data) into snp_guest_req which is allocated on stack now and accessed
by the GHCB caller under that mutex.
Stop allocating SEV_FW_BLOB_MAX_SIZE in snp_msg_alloc() as only one of four
callers needs it. Free the received blob in get_ext_report() right after it is
copied to the userspace. Possible future users of snp_send_guest_request() are
likely to have different ideas about the buffer size anyways.
Fixes: ae596615d9 ("virt: sev-guest: Reduce the scope of SNP command mutex")
Signed-off-by: Alexey Kardashevskiy <aik@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Nikunj A Dadhania <nikunj@amd.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250307013700.437505-3-aik@amd.com
Pull x86 SEV updates from Borislav Petkov:
- A segmented Reverse Map table (RMP) is a across-nodes distributed
table of sorts which contains per-node descriptors of each node-local
4K page, denoting its ownership (hypervisor, guest, etc) in the realm
of confidential computing. Add support for such a table in order to
improve referential locality when accessing or modifying RMP table
entries
- Add support for reading the TSC in SNP guests by removing any
interference or influence the hypervisor might have, with the goal of
making a confidential guest even more independent from the hypervisor
* tag 'x86_sev_for_v6.14_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/sev: Add the Secure TSC feature for SNP guests
x86/tsc: Init the TSC for Secure TSC guests
x86/sev: Mark the TSC in a secure TSC guest as reliable
x86/sev: Prevent RDTSC/RDTSCP interception for Secure TSC enabled guests
x86/sev: Prevent GUEST_TSC_FREQ MSR interception for Secure TSC enabled guests
x86/sev: Change TSC MSR behavior for Secure TSC enabled guests
x86/sev: Add Secure TSC support for SNP guests
x86/sev: Relocate SNP guest messaging routines to common code
x86/sev: Carve out and export SNP guest messaging init routines
virt: sev-guest: Replace GFP_KERNEL_ACCOUNT with GFP_KERNEL
virt: sev-guest: Remove is_vmpck_empty() helper
x86/sev/docs: Document the SNP Reverse Map Table (RMP)
x86/sev: Add full support for a segmented RMP table
x86/sev: Treat the contiguous RMP table as a single RMP segment
x86/sev: Map only the RMP table entries instead of the full RMP range
x86/sev: Move the SNP probe routine out of the way
x86/sev: Require the RMPREAD instruction after Zen4
x86/sev: Add support for the RMPREAD instruction
x86/sev: Prepare for using the RMPREAD instruction to access the RMP
Pull arm64 updates from Will Deacon:
"We've got a little less than normal thanks to the holidays in
December, but there's the usual summary below. The highlight is
probably the 52-bit physical addressing (LPA2) clean-up from Ard.
Confidential Computing:
- Register a platform device when running in CCA realm mode to enable
automatic loading of dependent modules
CPU Features:
- Update a bunch of system register definitions to pick up new field
encodings from the architectural documentation
- Add hwcaps and selftests for the new (2024) dpISA extensions
Documentation:
- Update EL3 (firmware) requirements for booting Linux on modern
arm64 designs
- Remove stale information about the kernel virtual memory map
Miscellaneous:
- Minor cleanups and typo fixes
Memory management:
- Fix vmemmap_check_pmd() to look at the PMD type bits
- LPA2 (52-bit physical addressing) cleanups and minor fixes
- Adjust physical address space depending upon whether or not LPA2 is
enabled
Perf and PMUs:
- Add port filtering support for NVIDIA's NVLINK-C2C Coresight PMU
- Extend AXI filtering support for the DDR PMU on NXP IMX SoCs
- Fix Designware PCIe PMU event numbering
- Add generic branch events for the Apple M1 CPU PMU
- Add support for Marvell Odyssey DDR and LLC-TAD PMUs
- Cleanups to the Hisilicon DDRC and Uncore PMU code
- Advertise discard mode for the SPE PMU
- Add the perf users mailing list to our MAINTAINERS entry"
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (64 commits)
Documentation: arm64: Remove stale and redundant virtual memory diagrams
perf docs: arm_spe: Document new discard mode
perf: arm_spe: Add format option for discard mode
MAINTAINERS: Add perf list for drivers/perf/
arm64: Remove duplicate included header
drivers/perf: apple_m1: Map generic branch events
arm64: rsi: Add automatic arm-cca-guest module loading
kselftest/arm64: Add 2024 dpISA extensions to hwcap test
KVM: arm64: Allow control of dpISA extensions in ID_AA64ISAR3_EL1
arm64/hwcap: Describe 2024 dpISA extensions to userspace
arm64/sysreg: Update ID_AA64SMFR0_EL1 to DDI0601 2024-12
arm64: Filter out SVE hwcaps when FEAT_SVE isn't implemented
drivers/perf: hisi: Set correct IRQ affinity for PMUs with no association
arm64/sme: Move storage of reg_smidr to __cpuinfo_store_cpu()
arm64: mm: Test for pmd_sect() in vmemmap_check_pmd()
arm64/mm: Replace open encodings with PXD_TABLE_BIT
arm64/mm: Rename pte_mkpresent() as pte_mkvalid()
arm64/sysreg: Update ID_AA64ISAR2_EL1 to DDI0601 2024-09
arm64/sysreg: Update ID_AA64ZFR0_EL1 to DDI0601 2024-09
arm64/sysreg: Update ID_AA64FPFR0_EL1 to DDI0601 2024-09
...
The TSM module provides guest identification and attestation when a
guest runs in CCA realm mode. By creating a dummy platform device,
let's ensure the module is automatically loaded. The udev daemon loads
the TSM module after it receives a device addition event. Once that
happens, it can be used earlier in the boot process to decrypt the
rootfs.
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Link: https://lore.kernel.org/r/20241220181236.172060-2-jeremy.linton@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
At present, the SEV guest driver exclusively handles SNP guest messaging. All
routines for sending guest messages are embedded within it.
To support Secure TSC, SEV-SNP guests must communicate with the AMD Security
Processor during early boot. However, these guest messaging functions are not
accessible during early boot since they are currently part of the guest
driver.
Hence, relocate the core SNP guest messaging functions to SEV common code and
provide an API for sending SNP guest messages.
No functional change, but just an export symbol added for
snp_send_guest_request() and dropped the export symbol on
snp_issue_guest_request() and made it static.
Signed-off-by: Nikunj A Dadhania <nikunj@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20250106124633.1418972-5-nikunj@amd.com
Currently, the sev-guest driver is the only user of SNP guest messaging. All
routines for initializing SNP guest messaging are implemented within the
sev-guest driver and are not available during early boot.
In preparation for adding Secure TSC guest support, carve out APIs to allocate
and initialize the guest messaging descriptor context and make it part of
coco/sev/core.c. As there is no user of sev_guest_platform_data anymore,
remove the structure.
Signed-off-by: Nikunj A Dadhania <nikunj@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20250106124633.1418972-4-nikunj@amd.com
Replace GFP_KERNEL_ACCOUNT with GFP_KERNEL in the sev-guest driver code.
GFP_KERNEL_ACCOUNT is typically used for accounting untrusted userspace
allocations. After auditing the sev-guest code, the following changes are
necessary:
* snp_init_crypto(): Use GFP_KERNEL as this is a trusted device probe
path.
Retain GFP_KERNEL_ACCOUNT in the following cases for robustness and
specific path requirements:
* alloc_shared_pages(): Although all allocations are limited, retain
GFP_KERNEL_ACCOUNT for future robustness.
* get_report() and get_ext_report(): These functions are on the unlocked
ioctl path and should continue using GFP_KERNEL_ACCOUNT.
Suggested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Nikunj A Dadhania <nikunj@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20250106124633.1418972-3-nikunj@amd.com
Remove is_vmpck_empty() which uses a local array allocation to check if the
VMPCK is empty and replace it with memchr_inv() to directly determine if the
VMPCK is empty without additional memory allocation.
[ bp: Massage commit message. ]
Suggested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Nikunj A Dadhania <nikunj@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20250106124633.1418972-2-nikunj@amd.com
In CoCo VMs it is possible for the untrusted host to cause
set_memory_decrypted() to fail such that an error is returned
and the resulting memory is shared. Callers need to take care
to handle these errors to avoid returning decrypted (shared)
memory to the page allocator, which could lead to functional
or security issues.
Leak the decrypted memory when set_memory_decrypted() fails,
and don't need to print an error since set_memory_decrypted()
will call WARN_ONCE().
Fixes: f4738f56d1 ("virt: tdx-guest: Add Quote generation support using TSM_REPORTS")
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/20240619111801.25630-1-lirongqing%40baidu.com
Pull arm64 fixes from Catalin Marinas:
"Nothing major, some left-overs from the recent merging window (MTE,
coco) and some newly found issues like the ptrace() ones.
- MTE/hugetlbfs:
- Set VM_MTE_ALLOWED in the arch code and remove it from the core
code for hugetlbfs mappings
- Fix copy_highpage() warning when the source is a huge page but
not MTE tagged, taking the wrong small page path
- drivers/virt/coco:
- Add the pKVM and Arm CCA drivers under the arm64 maintainership
- Fix the pkvm driver to fall back to ioremap() (and warn) if the
MMIO_GUARD hypercall fails
- Keep the Arm CCA driver default 'n' rather than 'm'
- A series of fixes for the arm64 ptrace() implementation,
potentially leading to the kernel consuming uninitialised stack
variables when PTRACE_SETREGSET is invoked with a length of 0
- Fix zone_dma_limit calculation when RAM starts below 4GB and
ZONE_DMA is capped to this limit
- Fix early boot warning with CONFIG_DEBUG_VIRTUAL=y triggered by a
call to page_to_phys() (from patch_map()) which checks pfn_valid()
before vmemmap has been set up
- Do not clobber bits 15:8 of the ASID used for TTBR1_EL1 and TLBI
ops when the kernel assumes 8-bit ASIDs but running under a
hypervisor on a system that implements 16-bit ASIDs (found running
Linux under Parallels on Apple M4)
- ACPI/IORT: Add PMCG platform information for HiSilicon HIP09A as it
is using the same SMMU PMCG as HIP09 and suffers from the same
errata
- Add GCS to cpucap_is_possible(), missed in the recent merge"
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: ptrace: fix partial SETREGSET for NT_ARM_GCS
arm64: ptrace: fix partial SETREGSET for NT_ARM_POE
arm64: ptrace: fix partial SETREGSET for NT_ARM_FPMR
arm64: ptrace: fix partial SETREGSET for NT_ARM_TAGGED_ADDR_CTRL
arm64: cpufeature: Add GCS to cpucap_is_possible()
coco: virt: arm64: Do not enable cca guest driver by default
arm64: mte: Fix copy_highpage() warning on hugetlb folios
arm64: Ensure bits ASID[15:8] are masked out when the kernel uses 8-bit ASIDs
ACPI/IORT: Add PMCG platform information for HiSilicon HIP09A
MAINTAINERS: Add CCA and pKVM CoCO guest support to the ARM64 entry
drivers/virt: pkvm: Don't fail ioremap() call if MMIO_GUARD fails
arm64: patching: avoid early page_to_phys()
arm64: mm: Fix zone_dma_limit calculation
arm64: mte: set VM_MTE_ALLOWED for hugetlbfs at correct place
Calling the MMIO_GUARD hypercall from guests which have not been
enrolled (e.g. because they are running without pvmfw) results in
-EINVAL being returned. In this case, MMIO_GUARD is not active
and so we can simply proceed with the normal ioremap() routine.
Don't fail ioremap() if MMIO_GUARD fails; instead WARN_ON_ONCE()
to highlight that the pvm environment is slightly wonky.
Fixes: 0f12694958 ("drivers/virt: pkvm: Intercept ioremap using pKVM MMIO_GUARD hypercall")
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20241202145731.6422-2-will@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The continual trickle of small conversion patches is grating on me, and
is really not helping. Just get rid of the 'remove_new' member
function, which is just an alias for the plain 'remove', and had a
comment to that effect:
/*
* .remove_new() is a relic from a prototype conversion of .remove().
* New drivers are supposed to implement .remove(). Once all drivers are
* converted to not use .remove_new any more, it will be dropped.
*/
This was just a tree-wide 'sed' script that replaced '.remove_new' with
'.remove', with some care taken to turn a subsequent tab into two tabs
to make things line up.
I did do some minimal manual whitespace adjustment for places that used
spaces to line things up.
Then I just removed the old (sic) .remove_new member function, and this
is the end result. No more unnecessary conversion noise.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull x86 SEV updates from Borislav Petkov:
- Do the proper memory conversion of guest memory in order to be able
to kexec kernels in SNP guests along with other adjustments and
cleanups to that effect
- Start converting and moving functionality from the sev-guest driver
into core code with the purpose of supporting the secure TSC SNP
feature where the hypervisor cannot influence the TSC exposed to the
guest anymore
- Add a "nosnp" cmdline option in order to be able to disable SNP
support in the hypervisor and thus free-up resources which are not
going to be used
- Cleanups
[ Reminding myself about the endless TLA's again: SEV is the AMD Secure
Encrypted Virtualization - Linus ]
* tag 'x86_sev_for_v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/sev: Cleanup vc_handle_msr()
x86/sev: Convert shared memory back to private on kexec
x86/mm: Refactor __set_clr_pte_enc()
x86/boot: Skip video memory access in the decompressor for SEV-ES/SNP
virt: sev-guest: Carve out SNP message context structure
virt: sev-guest: Reduce the scope of SNP command mutex
virt: sev-guest: Consolidate SNP guest messaging parameters to a struct
x86/sev: Cache the secrets page address
x86/sev: Handle failures from snp_init()
virt: sev-guest: Use AES GCM crypto library
x86/virt: Provide "nosnp" boot option for sev kernel command line
x86/virt: Move SEV-specific parsing into arch/x86/virt/svm
Introduce an arm-cca-guest driver that registers with
the configfs-tsm module to provide user interfaces for
retrieving an attestation token.
When a new report is requested the arm-cca-guest driver
invokes the appropriate RSI interfaces to query an
attestation token.
The steps to retrieve an attestation token are as follows:
1. Mount the configfs filesystem if not already mounted
mount -t configfs none /sys/kernel/config
2. Generate an attestation token
report=/sys/kernel/config/tsm/report/report0
mkdir $report
dd if=/dev/urandom bs=64 count=1 > $report/inblob
hexdump -C $report/outblob
rmdir $report
Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Link: https://lore.kernel.org/r/20241017131434.40935-11-steven.price@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Currently, the sev-guest driver is the only user of SNP guest messaging.
The snp_guest_dev structure holds all the allocated buffers, secrets page
and VMPCK details. In preparation for adding messaging allocation and
initialization APIs, decouple snp_guest_dev from messaging-related
information by carving out the guest message context
structure(snp_msg_desc).
Incorporate this newly added context into snp_send_guest_request() and all
related functions, replacing the use of the snp_guest_dev.
No functional change.
Signed-off-by: Nikunj A Dadhania <nikunj@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20241009092850.197575-7-nikunj@amd.com
The SNP command mutex is used to serialize access to the shared buffer,
command handling, and message sequence number.
All shared buffer, command handling, and message sequence updates are done
within snp_send_guest_request(), so moving the mutex to this function is
appropriate and maintains the critical section.
Since the mutex is now taken at a later point in time, remove the lockdep
checks that occur before taking the mutex.
Signed-off-by: Nikunj A Dadhania <nikunj@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20241009092850.197575-6-nikunj@amd.com
Add a snp_guest_req structure to eliminate the need to pass a long list of
parameters. This structure will be used to call the SNP Guest message
request API, simplifying the function arguments.
Update the snp_issue_guest_request() prototype to include the new guest
request structure.
Signed-off-by: Nikunj A Dadhania <nikunj@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20241009092850.197575-5-nikunj@amd.com
The sev-guest driver encryption code uses the crypto API for SNP guest
messaging with the AMD Security processor. In order to enable secure TSC,
SEV-SNP guests need to send such a TSC_INFO message before the APs are
booted. Details from the TSC_INFO response will then be used to program the
VMSA before the APs are brought up.
However, the crypto API is not available this early in the boot process.
In preparation for moving the encryption code out of sev-guest to support
secure TSC and to ease review, switch to using the AES GCM library
implementation instead.
Drop __enc_payload() and dec_payload() helpers as both are small and can be
moved to the respective callers.
Signed-off-by: Nikunj A Dadhania <nikunj@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Peter Gonda <pgonda@google.com>
Link: https://lore.kernel.org/r/20241009092850.197575-2-nikunj@amd.com
no_llseek had been defined to NULL two years ago, in commit 868941b144
("fs: remove no_llseek")
To quote that commit,
At -rc1 we'll need do a mechanical removal of no_llseek -
git grep -l -w no_llseek | grep -v porting.rst | while read i; do
sed -i '/\<no_llseek\>/d' $i
done
would do it.
Unfortunately, that hadn't been done. Linus, could you do that now, so
that we could finally put that thing to rest? All instances are of the
form
.llseek = no_llseek,
so it's obviously safe.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull arm64 updates from Will Deacon:
"The highlights are support for Arm's "Permission Overlay Extension"
using memory protection keys, support for running as a protected guest
on Android as well as perf support for a bunch of new interconnect
PMUs.
Summary:
ACPI:
- Enable PMCG erratum workaround for HiSilicon HIP10 and 11
platforms.
- Ensure arm64-specific IORT header is covered by MAINTAINERS.
CPU Errata:
- Enable workaround for hardware access/dirty issue on Ampere-1A
cores.
Memory management:
- Define PHYSMEM_END to fix a crash in the amdgpu driver.
- Avoid tripping over invalid kernel mappings on the kexec() path.
- Userspace support for the Permission Overlay Extension (POE) using
protection keys.
Perf and PMUs:
- Add support for the "fixed instruction counter" extension in the
CPU PMU architecture.
- Extend and fix the event encodings for Apple's M1 CPU PMU.
- Allow LSM hooks to decide on SPE permissions for physical
profiling.
- Add support for the CMN S3 and NI-700 PMUs.
Confidential Computing:
- Add support for booting an arm64 kernel as a protected guest under
Android's "Protected KVM" (pKVM) hypervisor.
Selftests:
- Fix vector length issues in the SVE/SME sigreturn tests
- Fix build warning in the ptrace tests.
Timers:
- Add support for PR_{G,S}ET_TSC so that 'rr' can deal with
non-determinism arising from the architected counter.
Miscellaneous:
- Rework our IPI-based CPU stopping code to try NMIs if regular IPIs
don't succeed.
- Minor fixes and cleanups"
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (94 commits)
perf: arm-ni: Fix an NULL vs IS_ERR() bug
arm64: hibernate: Fix warning for cast from restricted gfp_t
arm64: esr: Define ESR_ELx_EC_* constants as UL
arm64: pkeys: remove redundant WARN
perf: arm_pmuv3: Use BR_RETIRED for HW branch event if enabled
MAINTAINERS: List Arm interconnect PMUs as supported
perf: Add driver for Arm NI-700 interconnect PMU
dt-bindings/perf: Add Arm NI-700 PMU
perf/arm-cmn: Improve format attr printing
perf/arm-cmn: Clean up unnecessary NUMA_NO_NODE check
arm64/mm: use lm_alias() with addresses passed to memblock_free()
mm: arm64: document why pte is not advanced in contpte_ptep_set_access_flags()
arm64: Expose the end of the linear map in PHYSMEM_END
arm64: trans_pgd: mark PTEs entries as valid to avoid dead kexec()
arm64/mm: Delete __init region from memblock.reserved
perf/arm-cmn: Support CMN S3
dt-bindings: perf: arm-cmn: Add CMN S3
perf/arm-cmn: Refactor DTC PMU register access
perf/arm-cmn: Make cycle counts less surprising
perf/arm-cmn: Improve build-time assertion
...
Hook up pKVM's MMIO_GUARD hypercall so that ioremap() and friends will
register the target physical address as MMIO with the hypervisor,
allowing guest exits to that page to be emulated by the host with full
syndrome information.
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240830130150.8568-7-will@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
