== Background ==
CET defines two register states: CET user, which includes user-mode control
registers, and CET supervisor, which consists of shadow-stack pointers for
privilege levels 0-2.
Current kernels disable shadow stacks in kernel mode, making the CET
supervisor state unused and eliminating the need for context switching.
== Problem ==
To virtualize CET for guests, KVM must accurately emulate hardware
behavior. A key challenge arises because there is no CPUID flag to indicate
that shadow stack is supported only in user mode. Therefore, KVM cannot
assume guests will not enable shadow stacks in kernel mode and must
preserve the CET supervisor state of vCPUs.
== Solution ==
An initial proposal to manually save and restore CET supervisor states
using raw RDMSR/WRMSR in KVM was rejected due to performance concerns and
its impact on KVM's ABI. Instead, leveraging the kernel's FPU
infrastructure for context switching was favored [1].
The main question then became whether to enable the CET supervisor state
globally for all processes or restrict it to vCPU processes. This decision
involves a trade-off between a 24-byte XSTATE buffer waste for all non-vCPU
processes and approximately 100 lines of code complexity in the kernel [2].
The agreed approach is to first try this optimal solution [3], i.e.,
restricting the CET supervisor state to guest FPUs only and eliminating
unnecessary space waste.
The guest-only xfeature infrastructure has already been added. Now,
introduce CET supervisor xstate support as the first guest-only feature
to prepare for the upcoming CET virtualization in KVM.
Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
Signed-off-by: Chao Gao <chao.gao@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: John Allen <john.allen@amd.com>
Link: https://lore.kernel.org/kvm/ZM1jV3UPL0AMpVDI@google.com/ [1]
Link: https://lore.kernel.org/kvm/1c2fd06e-2e97-4724-80ab-8695aa4334e7@intel.com/ [2]
Link: https://lore.kernel.org/kvm/2597a87b-1248-b8ce-ce60-94074bc67ea4@intel.com/ [3]
Link: https://lore.kernel.org/all/20250522151031.426788-7-chao.gao%40intel.com
In preparation for upcoming CET virtualization support, the CET supervisor
state will be added as a "guest-only" feature, since it is required only by
KVM (i.e., guest FPUs). Establish the infrastructure for "guest-only"
features.
Define a new XFEATURE_MASK_GUEST_SUPERVISOR mask to specify features that
are enabled by default in guest FPUs but not in host FPUs. Specifically,
for any bit in this set, permission is granted and XSAVE space is allocated
during vCPU creation. Non-guest FPUs cannot enable guest-only features,
even dynamically, and no XSAVE space will be allocated for them.
The mask is currently empty, but this will be changed by a subsequent
patch.
Co-developed-by: Chao Gao <chao.gao@intel.com>
Signed-off-by: Chao Gao <chao.gao@intel.com>
Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Reviewed-by: John Allen <john.allen@amd.com>
Link: https://lore.kernel.org/all/20250522151031.426788-6-chao.gao%40intel.com
The initial values for fpstate::xfd differ between guest and host fpstates.
Currently, the initial values are passed as an argument to
__fpstate_reset(). But, __fpstate_reset() already assigns different default
features and sizes based on the type of fpstates (i.e., guest or host). So,
handle fpstate::xfd in a similar way to highlight the differences in the
initial xfd value between guest and host fpstates
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Chao Gao <chao.gao@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: John Allen <john.allen@amd.com>
Link: https://lore.kernel.org/all/aBuf7wiiDT0Wflhk@google.com/
Link: https://lore.kernel.org/all/20250522151031.426788-5-chao.gao%40intel.com
fpu_alloc_guest_fpstate() currently uses host defaults to initialize guest
fpstate and pseudo containers. Guest defaults were introduced to
differentiate the features and sizes of host and guest FPUs. Switch to
using guest defaults instead.
Adjust __fpstate_reset() to handle different defaults for host and guest
FPUs. And to distinguish between the types of FPUs, move the initialization
of indicators (is_guest and is_valloc) before the reset.
Suggested-by: Chang S. Bae <chang.seok.bae@intel.com>
Signed-off-by: Chao Gao <chao.gao@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Reviewed-by: John Allen <john.allen@amd.com>
Link: https://lore.kernel.org/all/20250522151031.426788-4-chao.gao%40intel.com
Currently, fpu->guest_perm is copied from fpu->perm, which is derived from
fpu_kernel_cfg.default_features.
Guest defaults were introduced to differentiate the features and sizes of
host and guest FPUs. Copying guest FPU permissions from the host will lead
to inconsistencies between the guest default features and permissions.
Initialize guest FPU permissions from guest defaults instead of host
defaults. This ensures that any changes to guest default features are
automatically reflected in guest permissions, which in turn guarantees
that fpstate_realloc() allocates a correctly sized XSAVE buffer for guest
FPUs.
Suggested-by: Chang S. Bae <chang.seok.bae@intel.com>
Signed-off-by: Chao Gao <chao.gao@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Reviewed-by: John Allen <john.allen@amd.com>
Link: https://lore.kernel.org/all/20250522151031.426788-3-chao.gao%40intel.com
Currently, guest and host FPUs share the same default features. However,
the CET supervisor xstate is the first feature that needs to be enabled
exclusively for guest FPUs. Enabling it for host FPUs leads to a waste of
24 bytes in the XSAVE buffer.
To support "guest-only" features, add a new structure to hold the
default features and sizes for guest FPUs to clearly differentiate them
from those for host FPUs.
Add two helpers to provide the default feature masks for guest and host
FPUs. Default features are derived by applying the masks to the maximum
supported features.
Note that,
1) for now, guest_default_mask() and host_default_mask() are identical.
This will change in a follow-up patch once guest permissions, default
xfeatures, and fpstate size are all converted to use the guest defaults.
2) only supervisor features will diverge between guest FPUs and host
FPUs, while user features will remain the same [1][2]. So, the new
vcpu_fpu_config struct does not include default user features and size
for the UABI buffer.
An alternative approach is adding a guest_only_xfeatures member to
fpu_kernel_cfg and adding two helper functions to calculate the guest
default xfeatures and size. However, calculating these defaults at runtime
would introduce unnecessary overhead.
Suggested-by: Chang S. Bae <chang.seok.bae@intel.com>
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Chao Gao <chao.gao@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: John Allen <john.allen@amd.com>
Link: https://lore.kernel.org/kvm/aAwdQ759Y6V7SGhv@google.com/ [1]
Link: https://lore.kernel.org/kvm/9ca17e1169805f35168eb722734fbf3579187886.camel@intel.com/ [2]
Link: https://lore.kernel.org/all/20250522151031.426788-2-chao.gao%40intel.com
When making a SPTE, cache whether or not the target PFN is host MMIO in
order to avoid multiple rounds of the slow path of kvm_is_mmio_pfn(), e.g.
hitting pat_pfn_immune_to_uc_mtrr() in particular can be problematic. KVM
currently avoids multiple calls by virtue of the two users being mutually
exclusive (.get_mt_mask() is Intel-only, shadow_me_value is AMD-only), but
that won't hold true if/when KVM needs to detect host MMIO mappings for
other reasons, e.g. for mitigating the MMIO Stale Data vulnerability.
No functional change intended.
Tested-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Link: https://lore.kernel.org/r/20250523011756.3243624-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Guard the call to kvm_x86_call(get_mt_mask) with an explicit check on
kvm_x86_ops.get_mt_mask so as to avoid unnecessarily calling
kvm_is_mmio_pfn(), which is moderately expensive for some backing types.
E.g. lookup_memtype() conditionally takes a system-wide spinlock if KVM
ends up being call pat_pfn_immune_to_uc_mtrr(), e.g. for DAX memory.
While the call to kvm_x86_ops.get_mt_mask() itself is elided, the compiler
still needs to compute all parameters, as it can't know at build time that
the call will be squashed.
<+243>: call 0xffffffff812ad880 <kvm_is_mmio_pfn>
<+248>: mov %r13,%rsi
<+251>: mov %rbx,%rdi
<+254>: movzbl %al,%edx
<+257>: call 0xffffffff81c26af0 <__SCT__kvm_x86_get_mt_mask>
Fixes: 3fee4837ef ("KVM: x86: remove shadow_memtype_mask")
Tested-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Link: https://lore.kernel.org/r/20250523011756.3243624-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
During driver probe we might be briefly using CT safe mode, which
is based on a delayed work, but usually we are able to stop this
once we have IRQ fully operational. However, if we abort the probe
quite early then during unwind we might try to destroy the workqueue
while there is still a pending delayed work that attempts to restart
itself which triggers a WARN.
This was recently observed during unsuccessful VF initialization:
[ ] xe 0000:00:02.1: probe with driver xe failed with error -62
[ ] ------------[ cut here ]------------
[ ] workqueue: cannot queue safe_mode_worker_func [xe] on wq xe-g2h-wq
[ ] WARNING: CPU: 9 PID: 0 at kernel/workqueue.c:2257 __queue_work+0x287/0x710
[ ] RIP: 0010:__queue_work+0x287/0x710
[ ] Call Trace:
[ ] delayed_work_timer_fn+0x19/0x30
[ ] call_timer_fn+0xa1/0x2a0
Exit the CT safe mode on unwind to avoid that warning.
Fixes: 09b286950f ("drm/xe/guc: Allow CTB G2H processing without G2H IRQ")
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://lore.kernel.org/r/20250612220937.857-3-michal.wajdeczko@intel.com
Initialize DR7 by writing its architectural reset value to always set
bit 10, which is reserved to '1', when "clearing" DR7 so as not to
trigger unanticipated behavior if said bit is ever unreserved, e.g. as
a feature enabling flag with inverted polarity.
Signed-off-by: Xin Li (Intel) <xin@zytor.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Reviewed-by: Sohil Mehta <sohil.mehta@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Sean Christopherson <seanjc@google.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Cc:stable@vger.kernel.org
Link: https://lore.kernel.org/all/20250620231504.2676902-3-xin%40zytor.com
Initialize DR6 by writing its architectural reset value to avoid
incorrectly zeroing DR6 to clear DR6.BLD at boot time, which leads
to a false bus lock detected warning.
The Intel SDM says:
1) Certain debug exceptions may clear bits 0-3 of DR6.
2) BLD induced #DB clears DR6.BLD and any other debug exception
doesn't modify DR6.BLD.
3) RTM induced #DB clears DR6.RTM and any other debug exception
sets DR6.RTM.
To avoid confusion in identifying debug exceptions, debug handlers
should set DR6.BLD and DR6.RTM, and clear other DR6 bits before
returning.
The DR6 architectural reset value 0xFFFF0FF0, already defined as
macro DR6_RESERVED, satisfies these requirements, so just use it to
reinitialize DR6 whenever needed.
Since clear_all_debug_regs() no longer zeros all debug registers,
rename it to initialize_debug_regs() to better reflect its current
behavior.
Since debug_read_clear_dr6() no longer clears DR6, rename it to
debug_read_reset_dr6() to better reflect its current behavior.
Fixes: ebb1064e7c ("x86/traps: Handle #DB for bus lock")
Reported-by: Sohil Mehta <sohil.mehta@intel.com>
Suggested-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Xin Li (Intel) <xin@zytor.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Reviewed-by: Sohil Mehta <sohil.mehta@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/lkml/06e68373-a92b-472e-8fd9-ba548119770c@intel.com/
Cc:stable@vger.kernel.org
Link: https://lore.kernel.org/all/20250620231504.2676902-2-xin%40zytor.com
The revamp of monitor/mwait test missed the original check of feature
availability [*]. If MONITOR/MWAIT is not supported or is disabled by
IA32_MISC_ENABLE on the host, executing MONITOR or MWAIT instruction
from guest doesn't cause monitor/mwait VM exits, but a #UD.
[*] https://lore.kernel.org/all/20240411210237.34646-1-zide.chen@intel.com/
Reported-by: Xuelian Guo <xuelian.guo@intel.com>
Fixes: 80fd663590 ("selftests: kvm: revamp MONITOR/MWAIT tests")
Signed-off-by: Chenyi Qiang <chenyi.qiang@intel.com>
Link: https://lore.kernel.org/r/20250620062219.342930-1-chenyi.qiang@intel.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Sparse complains:
sparse warnings: (new ones prefixed by >>)
>> drivers/pinctrl/meson/pinctrl-amlogic-a4.c:126:24: sparse: sparse:
symbol 'multi_mux_s7' was not declared. Should it be static?
>> drivers/pinctrl/meson/pinctrl-amlogic-a4.c:135:28: sparse: sparse:
symbol 's7_priv_data' was not declared. Should it be static?
>> drivers/pinctrl/meson/pinctrl-amlogic-a4.c:140:24: sparse: sparse:
symbol 'multi_mux_s6' was not declared. Should it be static?
>> drivers/pinctrl/meson/pinctrl-amlogic-a4.c:154:28: sparse: sparse:
symbol 's6_priv_data' was not declared. Should it be static?
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202506122145.wWAtKBoy-lkp@intel.com/
Cc: Xianwei Zhao <xianwei.zhao@amlogic.com>
Fixes: 1f8e5dfdda ("pinctrl: meson: support amlogic S6/S7/S7D SoC")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/20250624-amlogic-a4-fix-v1-1-03f0856d10cb@linaro.org
When the TDP MMU is enabled, i.e. when the shadow MMU isn't used until a
nested TDP VM is run, defer allocation of the array of hashed lists used
to track shadow MMU pages until the first shadow root is allocated.
Setting the list outside of mmu_lock is safe, as concurrent readers must
hold mmu_lock in some capacity, shadow pages can only be added (or removed)
from the list when mmu_lock is held for write, and tasks that are creating
a shadow root are serialized by slots_arch_lock. I.e. it's impossible for
the list to become non-empty until all readers go away, and so readers are
guaranteed to see an empty list even if they make multiple calls to
kvm_get_mmu_page_hash() in a single mmu_lock critical section.
Use smp_store_release() and smp_load_acquire() to access the hash table
pointer to ensure the stores to zero the lists are retired before readers
start to walk the list. E.g. if the compiler hoisted the store before the
zeroing of memory, for_each_gfn_valid_sp_with_gptes() could consume stale
kernel data.
Cc: James Houghton <jthoughton@google.com>
Link: https://lore.kernel.org/r/20250523001138.3182794-5-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Allocate VM structs via kvzalloc(), i.e. try to use a contiguous physical
allocation before falling back to __vmalloc(), to avoid the overhead of
establishing the virtual mappings. For non-debug builds, The SVM and VMX
(and TDX) structures are now just below 7000 bytes in the worst case
scenario (see below), i.e. are order-1 allocations, and will likely remain
that way for quite some time.
Add compile-time assertions in vendor code to ensure the size of the
structures, sans the memslot hash tables, are order-0 allocations, i.e.
are less than 4KiB. There's nothing fundamentally wrong with a larger
kvm_{svm,vmx,tdx} size, but given that the size of the structure (without
the memslots hash tables) is below 2KiB after 18+ years of existence,
more than doubling the size would be quite notable.
Add sanity checks on the memslot hash table sizes, partly to ensure they
aren't resized without accounting for the impact on VM structure size, and
partly to document that the majority of the size of VM structures comes
from the memslots.
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Link: https://lore.kernel.org/r/20250523001138.3182794-4-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Dynamically allocate the (massive) array of hashed lists used to track
shadow pages, as the array itself is 32KiB, i.e. is an order-3 allocation
all on its own, and is *exactly* an order-3 allocation. Dynamically
allocating the array will allow allocating "struct kvm" using kvmalloc(),
and will also allow deferring allocation of the array until it's actually
needed, i.e. until the first shadow root is allocated.
Opportunistically use kvmalloc() for the hashed lists, as an order-3
allocation is (stating the obvious) less likely to fail than an order-4
allocation, and the overhead of vmalloc() is undesirable given that the
size of the allocation is fixed.
Cc: Vipin Sharma <vipinsh@google.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Link: https://lore.kernel.org/r/20250523001138.3182794-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
The u32 variable voltage is being compared to less than zero and
this can never be true. Fix this by making voltage an int type which
is the same type as the return from the call to regulator_get_voltage.
Fixes: 5b797bcc00 ("pinctrl: eswin: Add EIC7700 pinctrl driver")
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Link: https://lore.kernel.org/20250623222004.280928-1-colin.i.king@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Move DT parse before pinctrl register. This ensures that device tree
parsing is done before calling devm_pinctrl_register() to prevent using
uninitialized pin resources.
Fixes: 545887eab6 ("pinctrl: canaan: Add support for k230 SoC")
Reported-by: Yao Zi <ziyao@disroot.org>
Signed-off-by: Ze Huang <huangze@whut.edu.cn>
Link: https://lore.kernel.org/20250624-k230-return-check-v1-2-6b4fc5ba0c41@whut.edu.cn
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Add a NULL check for the return value of of_get_property() when
retrieving the "pinmux" property in the group parser. This avoids
a potential NULL pointer dereference if the property is missing
from the device tree node.
Also fix a typo ("sintenel") in the device ID match table comment,
correcting it to "sentinel".
Fixes: 545887eab6 ("pinctrl: canaan: Add support for k230 SoC")
Reported-by: Yao Zi <ziyao@disroot.org>
Signed-off-by: Ze Huang <huangze@whut.edu.cn>
Link: https://lore.kernel.org/20250624-k230-return-check-v1-1-6b4fc5ba0c41@whut.edu.cn
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
G12B and SM1 have additional PWM pinmuxes for b, c, and d.
Signed-off-by: Da Xue <da@libre.computer>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/20250619022337.43900-1-da@libre.computer
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The zynq driver can be enabled for compile-testing on builds without
CONFIG_OF, leading to a link error:
ld.lld-21: error: undefined symbol: pinconf_generic_dt_node_to_map
referenced by pinconf-generic.h:231 (/home/arnd/arm-soc/include/linux/pinctrl/pinconf-generic.h:231)
drivers/pinctrl/pinctrl-zynq.o:(pinconf_generic_dt_node_to_map_all) in archive vmlinux.a
Prevent this with the proper compile time dependency.
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202506212021.deAhuaWr-lkp@intel.com/
Fixes: 1982621dec ("pinctrl: Allow compile testing for K210, TB10X and ZYNQ")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/20250620130814.2580678-1-arnd@kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
To avoid imposing an ordering constraint on userspace, allow 'invalid'
event channel targets to be configured in the IRQ routing table.
This is the same as accepting interrupts targeted at vCPUs which don't
exist yet, which is already the case for both Xen event channels *and*
for MSIs (which don't do any filtering of permitted APIC ID targets at
all).
If userspace actually *triggers* an IRQ with an invalid target, that
will fail cleanly, as kvm_xen_set_evtchn_fast() also does the same range
check.
If KVM enforced that the IRQ target must be valid at the time it is
*configured*, that would force userspace to create all vCPUs and do
various other parts of setup (in this case, setting the Xen long_mode)
before restoring the IRQ table.
Cc: stable@vger.kernel.org
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
Link: https://lore.kernel.org/r/e489252745ac4b53f1f7f50570b03fb416aa2065.camel@infradead.org
[sean: massage comment]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Use a preallocated per-vCPU bitmap for tracking the unpacked set of vCPUs
being targeted for Hyper-V's paravirt TLB flushing. If KVM_MAX_NR_VCPUS
is set to 4096 (which is allowed even for MAXSMP=n builds), putting the
vCPU mask on-stack pushes kvm_hv_flush_tlb() past the default FRAME_WARN
limit.
arch/x86/kvm/hyperv.c:2001:12: error: stack frame size (1288) exceeds limit (1024)
in 'kvm_hv_flush_tlb' [-Werror,-Wframe-larger-than]
2001 | static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc)
| ^
1 error generated.
Note, sparse_banks was given the same treatment by commit 7d5e88d301
("KVM: x86: hyper-v: Use preallocated buffer in 'struct kvm_vcpu_hv'
instead of on-stack 'sparse_banks'"), for the exact same reason.
Reported-by: Abinash Lalotra <abinashsinghlalotra@gmail.com>
Closes: https://lore.kernel.org/all/20250613111023.786265-1-abinashsinghlalotra@gmail.com
Link: https://lore.kernel.org/all/aEylI-O8kFnFHrOH@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
When creating an SEV-ES vCPU for intra-host migration, set its vmsa_pa to
INVALID_PAGE to harden against doing VMRUN with a bogus VMSA (KVM checks
for a valid VMSA page in pre_sev_run()).
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Tested-by: Liam Merwick <liam.merwick@oracle.com>
Link: https://lore.kernel.org/r/20250602224459.41505-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reject migration of SEV{-ES} state if either the source or destination VM
is actively creating a vCPU, i.e. if kvm_vm_ioctl_create_vcpu() is in the
section between incrementing created_vcpus and online_vcpus. The bulk of
vCPU creation runs _outside_ of kvm->lock to allow creating multiple vCPUs
in parallel, and so sev_info.es_active can get toggled from false=>true in
the destination VM after (or during) svm_vcpu_create(), resulting in an
SEV{-ES} VM effectively having a non-SEV{-ES} vCPU.
The issue manifests most visibly as a crash when trying to free a vCPU's
NULL VMSA page in an SEV-ES VM, but any number of things can go wrong.
BUG: unable to handle page fault for address: ffffebde00000000
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: Oops: 0000 [#1] SMP KASAN NOPTI
CPU: 227 UID: 0 PID: 64063 Comm: syz.5.60023 Tainted: G U O 6.15.0-smp-DEV #2 NONE
Tainted: [U]=USER, [O]=OOT_MODULE
Hardware name: Google, Inc. Arcadia_IT_80/Arcadia_IT_80, BIOS 12.52.0-0 10/28/2024
RIP: 0010:constant_test_bit arch/x86/include/asm/bitops.h:206 [inline]
RIP: 0010:arch_test_bit arch/x86/include/asm/bitops.h:238 [inline]
RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline]
RIP: 0010:PageHead include/linux/page-flags.h:866 [inline]
RIP: 0010:___free_pages+0x3e/0x120 mm/page_alloc.c:5067
Code: <49> f7 06 40 00 00 00 75 05 45 31 ff eb 0c 66 90 4c 89 f0 4c 39 f0
RSP: 0018:ffff8984551978d0 EFLAGS: 00010246
RAX: 0000777f80000001 RBX: 0000000000000000 RCX: ffffffff918aeb98
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffebde00000000
RBP: 0000000000000000 R08: ffffebde00000007 R09: 1ffffd7bc0000000
R10: dffffc0000000000 R11: fffff97bc0000001 R12: dffffc0000000000
R13: ffff8983e19751a8 R14: ffffebde00000000 R15: 1ffffd7bc0000000
FS: 0000000000000000(0000) GS:ffff89ee661d3000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffebde00000000 CR3: 000000793ceaa000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000b5f DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
sev_free_vcpu+0x413/0x630 arch/x86/kvm/svm/sev.c:3169
svm_vcpu_free+0x13a/0x2a0 arch/x86/kvm/svm/svm.c:1515
kvm_arch_vcpu_destroy+0x6a/0x1d0 arch/x86/kvm/x86.c:12396
kvm_vcpu_destroy virt/kvm/kvm_main.c:470 [inline]
kvm_destroy_vcpus+0xd1/0x300 virt/kvm/kvm_main.c:490
kvm_arch_destroy_vm+0x636/0x820 arch/x86/kvm/x86.c:12895
kvm_put_kvm+0xb8e/0xfb0 virt/kvm/kvm_main.c:1310
kvm_vm_release+0x48/0x60 virt/kvm/kvm_main.c:1369
__fput+0x3e4/0x9e0 fs/file_table.c:465
task_work_run+0x1a9/0x220 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x7f0/0x25b0 kernel/exit.c:953
do_group_exit+0x203/0x2d0 kernel/exit.c:1102
get_signal+0x1357/0x1480 kernel/signal.c:3034
arch_do_signal_or_restart+0x40/0x690 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x67/0xb0 kernel/entry/common.c:218
do_syscall_64+0x7c/0x150 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f87a898e969
</TASK>
Modules linked in: gq(O)
gsmi: Log Shutdown Reason 0x03
CR2: ffffebde00000000
---[ end trace 0000000000000000 ]---
Deliberately don't check for a NULL VMSA when freeing the vCPU, as crashing
the host is likely desirable due to the VMSA being consumed by hardware.
E.g. if KVM manages to allow VMRUN on the vCPU, hardware may read/write a
bogus VMSA page. Accessing PFN 0 is "fine"-ish now that it's sequestered
away thanks to L1TF, but panicking in this scenario is preferable to
potentially running with corrupted state.
Reported-by: Alexander Potapenko <glider@google.com>
Tested-by: Alexander Potapenko <glider@google.com>
Fixes: 0b020f5af0 ("KVM: SEV: Add support for SEV-ES intra host migration")
Fixes: b56639318b ("KVM: SEV: Add support for SEV intra host migration")
Cc: stable@vger.kernel.org
Cc: James Houghton <jthoughton@google.com>
Cc: Peter Gonda <pgonda@google.com>
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Tested-by: Liam Merwick <liam.merwick@oracle.com>
Reviewed-by: James Houghton <jthoughton@google.com>
Link: https://lore.kernel.org/r/20250602224459.41505-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
In the original implementation, krealloc() failure handling incorrectly
assigned the original memory pointer to NULL after kfree(), causing a
memory leak when reallocation failed.
Fixes: de845036f9 ("pinctrl: berlin: fix error return code of berlin_pinctrl_build_state()")
Signed-off-by: Yuan Chen <chenyuan@kylinos.cn>
Link: https://lore.kernel.org/20250620015343.21494-1-chenyuan_fl@163.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
In sunxi_pctrl_dt_node_to_map(), when krealloc() fails to resize
the pinctrl_map array, the function returns -ENOMEM directly
without freeing the previously allocated *map buffer. This results
in a memory leak of the original kmalloc_array allocation.
Fixes: e11dee2e98 ("pinctrl: sunxi: Deal with configless pins")
Signed-off-by: Yuan Chen <chenyuan@kylinos.cn>
Link: https://lore.kernel.org/20250620012708.16709-1-chenyuan_fl@163.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
We must unlock the mutex *after* the `out` label or we'd trigger a
deadlock in error path.
Fixes: dffe286e24 ("pinctrl: aw9523: use new GPIO line value setter callbacks")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/202506191952.A03cvn22-lkp@intel.com/
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Link: https://lore.kernel.org/20250619173537.64298-1-brgl@bgdev.pl
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Commit 869c788909 ("selftests: harness: Stop using setjmp()/longjmp()")
changed the harness structure. For some unknown reason, two build warnings
occur to the iommufd selftest:
iommufd.c: In function ‘wrapper_iommufd_mock_domain_all_aligns’:
iommufd.c:1807:17: warning: ‘mfd’ may be used uninitialized in this function
1807 | close(mfd);
| ^~~~~~~~~~
iommufd.c:1767:13: note: ‘mfd’ was declared here
1767 | int mfd;
| ^~~
iommufd.c: In function ‘wrapper_iommufd_mock_domain_all_aligns_copy’:
iommufd.c:1870:17: warning: ‘mfd’ may be used uninitialized in this function
1870 | close(mfd);
| ^~~~~~~~~~
iommufd.c:1819:13: note: ‘mfd’ was declared here
1819 | int mfd;
| ^~~
All the mfd have been used in the variant->file path only, so it's likely
a false alarm.
FWIW, the commit mentioned above does not cause this, yet it might affect
gcc in a certain way that resulted in the warnings. It is also found that
ading a dummy setjmp (which doesn't make sense) could mute the warnings:
https://lore.kernel.org/all/aEi8DV+ReF3v3Rlf@nvidia.com/
The job of this selftest is to catch kernel bug, while such warnings will
unlikely disrupt its role. Mute the warning by force initializing the mfd
and add an ASSERT_GT().
Link: https://patch.msgid.link/r/6951d85d5cd34cbf22abab7714542654e63ecc44.1750787928.git.nicolinc@nvidia.com
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
The hugepage test cases of iommufd_dirty_tracking have the 64MB and 128MB
coverages. Both of them are smaller than the default hugepage size 512MB,
when CONFIG_PAGE_SIZE_64KB=y. However, these test cases have a variant of
using huge pages, which would mmap(MAP_HUGETLB) using these smaller sizes
than the system hugepag size. This results in the kernel aligning up the
smaller size to 512MB. If a memory was located between the upper 64/128MB
size boundary and the hugepage 512MB boundary, it would get wiped out:
https://lore.kernel.org/all/aEoUhPYIAizTLADq@nvidia.com/
Given that this aligning up behavior is well documented, we have no choice
but to allocate a hugepage aligned size to avoid this unintended wipe out.
Instead of relying on the kernel's internal force alignment, pass the same
size to posix_memalign() and map().
Also, fix the FIXTURE_TEARDOWN() misusing munmap() to free the memory from
posix_memalign(), as munmap() doesn't destroy the allocator meta data. So,
call free() instead.
Fixes: a9af47e382 ("iommufd/selftest: Test IOMMU_HWPT_GET_DIRTY_BITMAP")
Link: https://patch.msgid.link/r/1ea8609ae6d523fdd4d8efb179ddee79c8582cb6.1750787928.git.nicolinc@nvidia.com
Cc: stable@vger.kernel.org
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Prevent other bits of mailbox power limit from being overwritten with 0.
This issue was due to a missing read and modify of current power limit,
before setting a requested mailbox power limit, which is added in this
patch.
v2:
- Improve commit message. (Anshuman)
v3:
- Rebase.
- Rephrase commit message. (Riana)
- Add read-modify-write variant of xe_hwmon_pcode_write_power_limit()
i.e. xe_hwmon_pcode_rmw_power_limit(). (Badal)
- Use xe_hwmon_pcode_rmw_power_limit() to set mailbox power limits.
- Remove xe_hwmon_pcode_write_power_limit() as all mailbox power limits
writes use xe_hwmon_pcode_rmw_power_limit() only.
v4:
- Use PWR_LIM in place of (PWR_LIM_EN | PWR_LIM_VAL) wherever
applicable. (Riana)
Fixes: 25a2aa779f ("drm/xe/hwmon: Add support to manage power limits though mailbox")
Reviewed-by: Riana Tauro <riana.tauro@intel.com>
Signed-off-by: Karthik Poosa <karthik.poosa@intel.com>
Reviewed-by: Badal Nilawar <badal.nilawar@intel.com>
Link: https://lore.kernel.org/r/20250617120030.612819-1-karthik.poosa@intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
(cherry picked from commit 8aa7306631)
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
I thought array declaration might be done in the same line as assigning the value
to it.
Hence, getting rid of extra steps of reiterating the array name.
Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Link: https://lore.kernel.org/r/20250611100256.31089-1-unixbhaskar@gmail.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
perl is not universal on all machines and should be replaced with awk,
which is much more common.
Before:
$ perf test "probe libc's inet_pton & backtrace it with ping" -v
--- start ---
test child forked, pid 145431
grep: Perl matching not supported in a --disable-perl-regexp build
FAIL: could not add event
---- end(-1) ----
121: probe libc's inet_pton & backtrace it with ping : FAILED!
After:
$ perf test "probe libc's inet_pton & backtrace it with ping" -v
121: probe libc's inet_pton & backtrace it with ping : Ok
Suggested-by: Ian Rogers <irogers@google.com>
Signed-off-by: Chun-Tse Shao <ctshao@google.com>
Reviewed-by: James Clark <james.clark@linaro.org>
Link: https://lore.kernel.org/r/20250620174034.819894-1-ctshao@google.com
[ fold James' suggestion not to escape _ in the event pattern. ]
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Remove the use of `Ktime` from the hrtimer code, which was originally
introduced as a temporary workaround. The hrtimer has now been fully
converted to use the `Instant` and `Delta` types instead.
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Link: https://lore.kernel.org/r/20250610132823.3457263-6-fujita.tomonori@gmail.com
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
Add a `TimerMode` associated type to the `HasHrTimer` trait to
represent the operational mode of the timer, such as absolute or
relative expiration. This new type must implement the `HrTimerMode`
trait, which defines how expiration values are interpreted.
Update the `start()` method to accept an `expires` parameter of type
`<Self::TimerMode as HrTimerMode>::Expires` instead of the fixed `Ktime`.
This enables different timer modes to provide strongly typed expiration
values, such as `Instant<C>` or `Delta`.
The `impl_has_hr_timer` macro is also extended to allow specifying the
`HrTimerMode`. In the following example, it guarantees that the
`start()` method for `Foo` only accepts `Instant<Monotonic>`. Using a
`Delta` or an `Instant` with a different clock source will result in a
compile-time error:
struct Foo {
#[pin]
timer: HrTimer<Self>,
}
impl_has_hr_timer! {
impl HasHrTimer<Self> for Foo {
mode : AbsoluteMode<Monotonic>,
field : self.timer
}
}
This design eliminates runtime mismatches between expires types and
clock sources, and enables stronger type-level guarantees throughout
hrtimer.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250610132823.3457263-5-fujita.tomonori@gmail.com
[ changed conversion method names to `as_*` - Andreas ]
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
Introduce the `HrTimerExpires` trait to represent types that can be
used as expiration values for high-resolution timers. Define a
required method, `into_nanos()`, which returns the expiration time as a
raw nanosecond value suitable for use with C's hrtimer APIs.
Also extend the `HrTimerMode` to use the `HrTimerExpires` trait.
This refactoring is a preparation for enabling hrtimer code to work
uniformly with both absolute and relative expiration modes.
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Link: https://lore.kernel.org/r/20250610132823.3457263-4-fujita.tomonori@gmail.com
[ changed conversion method names to `as_*` - Andreas ]
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
Only need the flush for DPT host updates here. Normal GGTT updates don't
need special flush.
Fixes: 01570b4469 ("drm/xe/bmg: implement Wa_16023588340")
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: stable@vger.kernel.org # v6.12+
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://lore.kernel.org/r/20250606104546.1996818-4-matthew.auld@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Flushing l2 is only needed after all data has been written.
Fixes: 01570b4469 ("drm/xe/bmg: implement Wa_16023588340")
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: stable@vger.kernel.org # v6.12+
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://lore.kernel.org/r/20250606104546.1996818-3-matthew.auld@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
A missed evsel__close before evsel__delete was the source of leaking
perf events due to a hybrid test. Add asserts in debug builds so that
this shouldn't happen in the future. Add puts missing on the cpu map
and thread maps.
Signed-off-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20250617223356.2752099-4-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Caught by leak sanitizer running "perf trace BTF general tests". Make
the ordered_events initialization unconditional and early so that
trace__exit cleanup is simple - ordered_events__init doesn't allocate
and just sets up 4 values and inits 3 list heads.
Signed-off-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20250617223356.2752099-3-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
When processing the perf data file generated with multiple events,
the flamegraph script will count all the events regardless of
different event names.
This patch tries to add a -e option to specify the event name that
the flamegraph will be generated accordingly. If the -e option omitted,
the behavior remains unchanged.
Signed-off-by: Tianyou Li <tianyou.li@intel.com>
Reviewed-by: Pan Deng <pan.deng@intel.com>
Reviewed-by: Zhiguo Zhou <zhiguo.zhou@intel.com>
Reviewed-by: Wangyang Guo <wangyang.guo@intel.com>
Reviewed-by: Tim Chen <tim.c.chen@linux.intel.com>
Link: https://lore.kernel.org/r/20250610040536.2390060-2-tianyou.li@intel.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
If specify the perf data file with -i option, the script will try to
read the header information regardless of the file name specified,
instead it will try to access the perf.data. This simple patch use the
file name from -i option for command perf report --header-only to read
the header.
Signed-off-by: Tianyou Li <tianyou.li@intel.com>
Reviewed-by: Pan Deng <pan.deng@intel.com>
Reviewed-by: Zhiguo Zhou <zhiguo.zhou@intel.com>
Reviewed-by: Wangyang Guo <wangyang.guo@intel.com>
Reviewed-by: Tim Chen <tim.c.chen@linux.intel.com>
Link: https://lore.kernel.org/r/20250610040536.2390060-1-tianyou.li@intel.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
