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For consistency with __vdso_clock_gettime64() there should also be a
64-bit variant of clock_getres(). This will allow the extension of
CONFIG_COMPAT_32BIT_TIME to the vDSO and finally the removal of 32-bit
time types from the kernel and UAPI.
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Link: https://patch.msgid.link/20260114-vdso-powerpc-align-v1-1-acf09373d568@linutronix.de
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Fix a goof in the comment that documents KVM's logic for enabling AVIC by
default to reference Zen5+ as family 0x1A (Zen5), not family 0x19 (Zen4).
The code is correct (checks for _greater_ than 0x19), only the comment is
flawed.
Opportunistically tweak the check too, even though it's already correct,
so that both the comment and the code reference 0x1A, and so that the
checks are "ascending", i.e. check Zen4 and then Zen5+.
No functional change intended.
Fixes: ca2967de5a5b ("KVM: SVM: Enable AVIC by default for Zen4+ if x2AVIC is support")
Acked-by: Naveen N Rao (AMD) <naveen@kernel.org>
Link: https://patch.msgid.link/20260109035037.1015073-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Debugging the loader on baremetal does make sense, so enable it there
too.
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://patch.msgid.link/20260108165028.27417-1-bp@kernel.org
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MMC A and C are mis-represented as having their "clkin0" input connected to
xtal while it is actually connected to the MMC clock, probably in an
attempt to provide 24MHz to the device on this input.
Fix this and assign the clock to 24MHz to actually provide the required
rate.
Fixes: 3ab9d54b5d84 ("arm64: dts: amlogic: enable some device nodes for S4")
Tested-by: Nick Xie <nick@khadas.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patch.msgid.link/20260114-amlogic-s4-mmc-fixup-v3-2-a4d3e136b3f2@baylibre.com
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
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The amlogic MMC driver operate with the assumption that MMC clock
is configured to provide 24MHz. It uses this path for low
rates such as 400kHz.
This assumption did hold true until but it now, but it is apparently
not the case with s4. The clock has been reported to provide 1GHz
instead. This is most likely due to how the bootloader is using the MMC
clock on this platform.
Regardless of why the MMC clock rate is 1GHz, if the MMC driver expects
24MHz, the clock should be properly assigned, so assign it.
Reported-by: Nick Xie <nick@khadas.com>
Closes: https://lore.kernel.org/linux-amlogic/20260113011931.40424-1-nick@khadas.com/
Fixes: 3ab9d54b5d84 ("arm64: dts: amlogic: enable some device nodes for S4")
Tested-by: Nick Xie <nick@khadas.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patch.msgid.link/20260114-amlogic-s4-mmc-fixup-v3-1-a4d3e136b3f2@baylibre.com
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
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Amlogic sound card assigned-clock-parents only have <0> and are useless.
Remove them.
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patch.msgid.link/20260114-amlogic-parent-clock-cleanup-v1-1-31078b1e4a2c@baylibre.com
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
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Include <asm/stackpage/nvhe.h> for kvm_arm_hyp_stack_base
declaration which fixes the following sparse warning:
arch/arm64/kvm/arm.c:63:1: warning: symbol 'kvm_arm_hyp_stack_base' was not declared. Should it be static?
Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Link: https://patch.msgid.link/20260112160413.603493-1-ben.dooks@codethink.co.uk
Signed-off-by: Marc Zyngier <maz@kernel.org>
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Calculate the hypervisor's VA size only once to maintain consistency
between the memory layout and MMU initialization logic. Previously the
two would be inconsistent when the kernel is configured for less than
IDMAP_VA_BITS of VA space.
Signed-off-by: Petteri Kangaslampi <pekangas@google.com>
Tested-by: Vincent Donnefort <vdonnefort@google.com>
Link: https://patch.msgid.link/20260113194409.2970324-2-pekangas@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
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Align the name of the regulator with the design schematic. Also fix up
the gpio property to the new "gpios" property name, and add the
GPIO_ACTIVE_HIGH flag. The flag is actively ignored in Linux in favor of
the old "enable-active-high" property; nevertheless it is the correct
description.
Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
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Following the changes in the binding for the SafeXcel crypto
engine, add a SoC specific compatible to the existing crypto
node and, while at it, also change the fallback compatible to
inside-secure,safexcel-eip97ies as the eip97 one is deprecated.
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
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Add the required pinmux and assign the right interrupts-extended
to the DA9211 regulator (PIO pin 15).
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
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The MT6332 PMIC leds node was named "mt6332-led", however, the
binding rightfully enforces using the generic node name "leds".
Change it to the latter to resolve dtbs_check warnings.
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
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Add the "mediatek,mt6795-scpsys" compatible to the SCPSYS node
and remove #power-domain-cells (retaining it only in the power
controller subnode) to resolve dtbs_check warnings.
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
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The ldo-vcamio regulator is named "vcam_io", however, the binding
only allows "vcamio" as name: change it to the latter to resolve
a dtbs_check warning.
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
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Reading the byte/char output_len with get_unaligned_le32() can trigger
compiler warnings due to the size read. Avoid these warnings by using
type punning. This avoids issues when switching get_unaligned_t() to
__builtin_memcpy().
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20251016205126.2882625-2-irogers@google.com
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The cache parameter of getcpu() is useless nowadays for various reasons.
* It is never passed by userspace for either the vDSO or syscalls.
* It is never used by the kernel.
* It could not be made to work on the current vDSO architecture.
* The structure definition is not part of the UAPI headers.
* vdso_getcpu() is superseded by restartable sequences in any case.
Remove the struct and its header.
As a side-effect this gets rid of an unwanted inclusion of the linux/
header namespace from vDSO code.
[ tglx: Adapt to s390 upstream changes */
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Heiko Carstens <hca@linux.ibm.com> # s390
Link: https://patch.msgid.link/20251230-getcpu_cache-v3-1-fb9c5f880ebe@linutronix.de
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Pull bpf fixes from Alexei Starovoitov:
- Fix incorrect usage of BPF_TRAMP_F_ORIG_STACK in riscv JIT (Menglong
Dong)
- Fix reference count leak in bpf_prog_test_run_xdp() (Tetsuo Handa)
- Fix metadata size check in bpf_test_run() (Toke Høiland-Jørgensen)
- Check that BPF insn array is not allowed as a map for const strings
(Deepanshu Kartikey)
* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
bpf: Fix reference count leak in bpf_prog_test_run_xdp()
bpf: Reject BPF_MAP_TYPE_INSN_ARRAY in check_reg_const_str()
selftests/bpf: Update xdp_context_test_run test to check maximum metadata size
bpf, test_run: Subtract size of xdp_frame from allowed metadata size
riscv, bpf: Fix incorrect usage of BPF_TRAMP_F_ORIG_STACK
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Add a build-time assertiont that Hyper-V's "enlightened" exit code is that,
same as the AMD-defined "Reserved for Host" exit code, mostly to help
readers connect the dots and understand why synthesizing a software-defined
exit code is safe/ok.
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://patch.msgid.link/20251230211347.4099600-9-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Explicitly clamp the exit code used to index KVM's exit handlers to guard
against Spectre-like attacks, mainly to provide consistency between VMX
and SVM (VMX was given the same treatment by commit c926f2f7230b ("KVM:
x86: Protect exit_reason from being used in Spectre-v1/L1TF attacks").
For normal VMs, it's _extremely_ unlikely the exit code could be used to
exploit a speculation vulnerability, as the exit code is set by hardware
and unexpected/unknown exit codes should be quite well bounded (as is/was
the case with VMX). But with SEV-ES+, the exit code is guest-controlled
as it comes from the GHCB, not from hardware, i.e. an attack from the
guest is at least somewhat plausible.
Irrespective of SEV-ES+, hardening KVM is easy and inexpensive, and such
an attack is theoretically possible.
Link: https://patch.msgid.link/20251230211347.4099600-8-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Limit KVM's incorrect check for VMXEXIT_INVALID, a.k.a. SVM_EXIT_ERR, to
running as a VM, as detected by X86_FEATURE_HYPERVISOR. The exit_code and
all failure codes, e.g. VMXEXIT_INVALID, are 64-bit values, and so checking
only bits 31:0 could result in false positives when running on non-broken
hardware, e.g. in the extremely unlikely scenario exit code 0xffffffffull
is ever generated by hardware.
Keep the 32-bit check to play nice with running on broken KVM (for years,
KVM has not set bits 63:32 when synthesizing nested SVM VM-Exits).
Reviewed-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251230211347.4099600-7-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Fix KVM's long-standing buggy handling of SVM's exit_code as a 32-bit
value. Per the APM and Xen commit d1bd157fbc ("Big merge the HVM
full-virtualisation abstractions.") (which is arguably more trustworthy
than KVM), offset 0x70 is a single 64-bit value:
070h 63:0 EXITCODE
Track exit_code as a single u64 to prevent reintroducing bugs where KVM
neglects to correctly set bits 63:32.
Fixes: 6aa8b732ca01 ("[PATCH] kvm: userspace interface")
Cc: Jim Mattson <jmattson@google.com>
Cc: Yosry Ahmed <yosry.ahmed@linux.dev>
Reviewed-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251230211347.4099600-6-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Explicitly filter out 64-bit exit codes when invoking exit handlers, as
svm_exit_handlers[] will never be sized with entries that use bits 63:32.
Processing the non-failing exit code as a 32-bit value will allow tracking
exit_code as a single 64-bit value (which it is, architecturally). This
will also allow hardening KVM against Spectre-like attacks without needing
to do silly things to avoid build failures on 32-bit kernels
(array_index_nospec() rightly asserts that the index fits in an "unsigned
long").
Omit the check when running as a VM, as KVM has historically failed to set
bits 63:32 appropriately when synthesizing VM-Exits, i.e. KVM could get
false positives when running as a VM on an older, broken KVM/kernel. From
a functional perspective, omitting the check is "fine", as any unwanted
collision between e.g. VMEXIT_INVALID and a 32-bit exit code will be
fatal to KVM-on-KVM regardless of what KVM-as-L1 does.
Reviewed-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251230211347.4099600-5-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Check for an unexpected/unhandled VM-Exit after the manual RETPOLINE=y
handling. The entire point of the RETPOLINE checks is to optimize for
common VM-Exits, i.e. checking for the rare case of an unsupported
VM-Exit is counter-productive. This also aligns SVM and VMX exit handling.
No functional change intended.
Reviewed-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251230211347.4099600-4-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Fold svm_check_exit_valid() and svm_handle_invalid_exit() into their sole
caller, svm_invoke_exit_handler(), as having tiny single-use helpers makes
the code unncessarily difficult to follow. This will also allow for
additional cleanups in svm_invoke_exit_handler().
No functional change intended.
Suggested-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Reviewed-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com>
Link: https://patch.msgid.link/20251230211347.4099600-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Add a helper to detect VMRUN failures so that KVM can guard against its
own long-standing bug, where KVM neglects to set exitcode[63:32] when
synthesizing a nested VMFAIL_INVALID VM-Exit. This will allow fixing
KVM's mess of treating exitcode as two separate 32-bit values without
breaking KVM-on-KVM when running on an older, unfixed KVM.
Cc: Jim Mattson <jmattson@google.com>
Cc: Yosry Ahmed <yosry.ahmed@linux.dev>
Reviewed-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251230211347.4099600-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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The use of static_call_cond() is essentially the same as static_call() on
x86 (e.g. static_call() now handles a NULL pointer as a NOP), and then the
kvm_x86_call() is added to improve code readability and maintainability
for keeping consistent code style.
Fixes 8d032b683c29 ("KVM: TDX: create/destroy VM structure")
Link: https://lore.kernel.org/all/3916caa1dcd114301a49beafa5030eca396745c1.1679456900.git.jpoimboe@kernel.org/
Link: https://lore.kernel.org/r/20240507133103.15052-3-wei.w.wang@intel.com
Signed-off-by: Jun Miao <jun.miao@intel.com>
Link: https://patch.msgid.link/20260105065423.1870622-1-jun.miao@intel.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Ignore -EBUSY when checking nested events after exiting a blocking state
while L2 is active, as exiting to userspace will generate a spurious
userspace exit, usually with KVM_EXIT_UNKNOWN, and likely lead to the VM's
demise. Continuing with the wakeup isn't perfect either, as *something*
has gone sideways if a vCPU is awakened in L2 with an injected event (or
worse, a nested run pending), but continuing on gives the VM a decent
chance of surviving without any major side effects.
As explained in the Fixes commits, it _should_ be impossible for a vCPU to
be put into a blocking state with an already-injected event (exception,
IRQ, or NMI). Unfortunately, userspace can stuff MP_STATE and/or injected
events, and thus put the vCPU into what should be an impossible state.
Don't bother trying to preserve the WARN, e.g. with an anti-syzkaller
Kconfig, as WARNs can (hopefully) be added in paths where _KVM_ would be
violating x86 architecture, e.g. by WARNing if KVM attempts to inject an
exception or interrupt while the vCPU isn't running.
Cc: Alessandro Ratti <alessandro@0x65c.net>
Cc: stable@vger.kernel.org
Fixes: 26844fee6ade ("KVM: x86: never write to memory from kvm_vcpu_check_block()")
Fixes: 45405155d876 ("KVM: x86: WARN if a vCPU gets a valid wakeup that KVM can't yet inject")
Link: https://syzkaller.appspot.com/text?tag=ReproC&x=10d4261a580000
Reported-by: syzbot+1522459a74d26b0ac33a@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/671bc7a7.050a0220.455e8.022a.GAE@google.com
Link: https://patch.msgid.link/20260109030657.994759-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Tag sev_supported_vmsa_features with __ro_after_init as it's configured by
sev_hardware_setup() and never written after initial configuration (and if
it were, that'd be a blatant bug).
Opportunistically relocate the variable out of the module params area now
that sev_es_debug_swap_enabled is gone (which largely motivated its
original location).
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://patch.msgid.link/20260109033101.1005769-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Rip out the DebugSwap module param, as the sequence of events that led to
its inclusion was one big mistake, the param no longer serves any purpose.
Commit d1f85fbe836e ("KVM: SEV: Enable data breakpoints in SEV-ES") goofed
by not adding a way for the userspace VMM to control the feature.
Functionally, that was fine, but it broke attestation signatures because
SEV_FEATURES are included in the signature.
Commit 5abf6dceb066 ("SEV: disable SEV-ES DebugSwap by default") fixed that
issue, but the underlying flaw of userspace not having a way to control
SEV_FEATURES was still there.
That flaw was addressed by commit 4f5defae7089 ("KVM: SEV: introduce
KVM_SEV_INIT2 operation"), and so then 4dd5ecacb9a4 ("KVM: SEV: allow
SEV-ES DebugSwap again") re-enabled DebugSwap by default.
Now that the dust has settled, the module param doesn't serve any
meaningful purpose.
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://patch.msgid.link/20260109033101.1005769-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Fold the calls to .hwapic_isr_update() in kvm_apic_set_state(),
kvm_lapic_reset(), and __kvm_vcpu_update_apicv() into
kvm_apic_update_apicv(), as updating SVI is directly related to updating
KVM's own cache of ISR information, e.g. SVI is more or less the APICv
equivalent of highest_isr_cache.
Note, calling .hwapic_isr_update() during kvm_apic_update_apicv() has
benign side effects, as doing so changes the orders of the calls in
kvm_lapic_reset() and kvm_apic_set_state(), specifically with respect to
to the order between .hwapic_isr_update() and .apicv_post_state_restore().
However, the changes in ordering are glorified nops as the former hook is
VMX-only and the latter is SVM-only.
Reviewed-by: Chao Gao <chao.gao@intel.com>
Link: https://patch.msgid.link/20260109034532.1012993-9-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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If L1's virtual APIC mode changes while L2 is active, e.g. because L1
doesn't intercept writes to the APIC_BASE MSR and L2 changes the mode,
temporarily load vmcs01 and do all of the necessary actions instead of
deferring the update until the next nested VM-Exit.
This will help in fixing yet more issues related to updates while L2 is
active, e.g. KVM neglects to update vmcs02 MSR intercepts if vmcs01's MSR
intercepts are modified while L2 is active. Not updating x2APIC MSRs is
benign because vmcs01's settings are not factored into vmcs02's bitmap, but
deferring the x2APIC MSR updates would create a weird, inconsistent state.
Reviewed-by: Chao Gao <chao.gao@intel.com>
Link: https://patch.msgid.link/20260109034532.1012993-8-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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If the KVM-owned APIC-access page is migrated while L2 is running,
temporarily load vmcs01 and immediately update APIC_ACCESS_ADDR instead
of deferring the update until the next nested VM-Exit. Once changing
the virtual APIC mode is converted to always do on-demand updates, all
of the "defer until vmcs01 is active" logic will be gone.
Reviewed-by: Chao Gao <chao.gao@intel.com>
Link: https://patch.msgid.link/20260109034532.1012993-7-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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If APICv is (un)inhibited while L2 is running, temporarily load vmcs01 and
immediately refresh the APICv controls in vmcs01 instead of deferring the
update until the next nested VM-Exit. This all but eliminates potential
ordering issues due to vmcs01 not being synchronized with
kvm_lapic.apicv_active, e.g. where KVM _thinks_ it refreshed APICv, but
vmcs01 still contains stale state.
Reviewed-by: Chao Gao <chao.gao@intel.com>
Link: https://patch.msgid.link/20260109034532.1012993-6-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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If APICv is activated while L2 is running and triggers an SVI update,
temporarily load vmcs01 and immediately update SVI instead of deferring
the update until the next nested VM-Exit. This will eventually allow
killing off kvm_apic_update_hwapic_isr(), and all of nVMX's deferred
APICv updates.
Reviewed-by: Chao Gao <chao.gao@intel.com>
Link: https://patch.msgid.link/20260109034532.1012993-5-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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If KVM updates L1's TPR Threshold while L2 is active, temporarily load
vmcs01 and immediately update TPR_THRESHOLD instead of deferring the
update until the next nested VM-Exit. Deferring the TPR Threshold update
is relatively straightforward, but for several APICv related updates,
deferring updates creates ordering and state consistency problems, e.g.
KVM at-large thinks APICv is enabled, but vmcs01 is still running with
stale (and effectively unknown) state.
Reviewed-by: Chao Gao <chao.gao@intel.com>
Link: https://patch.msgid.link/20260109034532.1012993-4-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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If KVM toggles "CPU dirty logging", a.k.a. Page-Modification Logging (PML),
while L2 is active, temporarily load vmcs01 and immediately update the
relevant controls instead of deferring the update until the next nested
VM-Exit. For PML, deferring the update is relatively straightforward, but
for several APICv related updates, deferring updates creates ordering and
state consistency problems, e.g. KVM at-large thinks APICv is enabled, but
vmcs01 is still running with stale (and effectively unknown) state.
Convert PML first precisely because it's the simplest case to handle: if
something is broken with the vmcs01 <=> vmcs02 dance, then hopefully bugs
will bisect here.
Reviewed-by: Chao Gao <chao.gao@intel.com>
Link: https://patch.msgid.link/20260109034532.1012993-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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When neither sysenter32 nor syscall32 is available (on either
FRED-capable 64-bit hardware or old 32-bit hardware), there is no
reason to do a bunch of stack shuffling in __kernel_vsyscall.
Unfortunately, just overwriting the initial "push" instructions will
mess up the CFI annotations, so suffer the 3-byte NOP if not
applicable.
Similarly, inline the int $0x80 when doing inline system calls in the
vdso instead of calling __kernel_vsyscall.
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://patch.msgid.link/20251216212606.1325678-11-hpa@zytor.com
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In most cases, the use of "fast 32-bit system call" depends either on
X86_FEATURE_SEP or X86_FEATURE_SYSENTER32 || X86_FEATURE_SYSCALL32.
However, nearly all the logic for both is identical.
Define X86_FEATURE_SYSFAST32 which indicates that *either* SYSENTER32 or
SYSCALL32 should be used, for either 32- or 64-bit kernels. This
defaults to SYSENTER; use SYSCALL if the SYSCALL32 bit is also set.
As this removes ALL existing uses of X86_FEATURE_SYSENTER32, which is
a kernel-only synthetic feature bit, simply remove it and replace it
with X86_FEATURE_SYSFAST32.
This leaves an unused alternative for a true 32-bit kernel, but that
should really not matter in any way.
The clearing of X86_FEATURE_SYSCALL32 can be removed once the patches
for automatically clearing disabled features has been merged.
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://patch.msgid.link/20251216212606.1325678-10-hpa@zytor.com
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Abstract out the calling of true system calls from the vdso into
macros.
It has been a very long time since gcc did not allow %ebx or %ebp in
inline asm in 32-bit PIC mode; remove the corresponding hacks.
Remove the use of memory output constraints in gettimeofday.h in favor
of "memory" clobbers. The resulting code is identical for the current
use cases, as the system call is usually a terminal fallback anyway,
and it merely complicates the macroization.
This patch adds only a handful of more lines of code than it removes,
and in fact could be made substantially smaller by removing the macros
for the argument counts that aren't currently used, however, it seems
better to be general from the start.
[ v3: remove stray comment from prototyping; remove VDSO_SYSCALL6()
since it would require special handling on 32 bits and is
currently unused. (Uros Biszjak)
Indent nested preprocessor directives. ]
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Uros Bizjak <ubizjak@gmail.com>
Link: https://patch.msgid.link/20251216212606.1325678-9-hpa@zytor.com
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Currently the vdso doesn't include .note.gnu.property or a GNU noexec
stack annotation (the -z noexecstack in the linker script is
ineffective because we specify PHDRs explicitly.)
The motivation is that the dynamic linker currently do not check
these.
However, this is a weak excuse: the vdso*.so are also supposed to be
usable at link libraries, and there is no reason why the dynamic
linker might not want or need to check these in the future, so add
them back in -- it is trivial enough.
Use symbolic constants for the PHDR permission flags.
[ v4: drop unrelated formatting changes ]
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://patch.msgid.link/20251216212606.1325678-8-hpa@zytor.com
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The vdso32 sigreturn.S contains open-coded DWARF bytecode, which
includes a hack for gdb to not try to step back to a previous call
instruction when backtracing from a signal handler.
Neither of those are necessary anymore: the backtracing issue is
handled by ".cfi_entry simple" and ".cfi_signal_frame", both of which
have been supported for a very long time now, which allows the
remaining frame to be built using regular .cfi annotations.
Add a few more register offsets to the signal frame just for good
measure.
Replace the nop on fallthrough of the system call (which should never,
ever happen) with a ud2a trap.
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://patch.msgid.link/20251216212606.1325678-7-hpa@zytor.com
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A macro SYSCALL_ENTER_KERNEL was defined in sigreturn.S, with the
ability of overriding it. The override capability, however, is not
used anywhere, and the macro name is potentially confusing because it
seems to imply that sysenter/syscall could be used here, which is NOT
true: the sigreturn system calls MUST use int $0x80.
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://patch.msgid.link/20251216212606.1325678-6-hpa@zytor.com
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There is no fundamental reason to use the int80_landing_pad symbol to
adjust ip when moving the vdso. If ip falls within the vdso, and the
vdso is moved, we should change the ip accordingly, regardless of mode
or location within the vdso. This *currently* can only happen on 32
bits, but there isn't any reason not to do so generically.
Note that if this is ever possible from a vdso-internal call, then the
user space stack will also needed to be adjusted (as well as the
shadow stack, if enabled.) Fortunately this is not currently the case.
At the moment, we don't even consider other threads when moving the
vdso. The assumption is that it is only used by process freeze/thaw
for migration, where this is not an issue.
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://patch.msgid.link/20251216212606.1325678-5-hpa@zytor.com
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- Separate out the vdso sources into common, vdso32, and vdso64
directories.
- Build the 32- and 64-bit vdsos in their respective subdirectories;
this greatly simplifies the build flags handling.
- Unify the mangling of Makefile flags between the 32- and 64-bit
vdso code as much as possible; all common rules are put in
arch/x86/entry/vdso/common/Makefile.include. The remaining
is very simple for 32 bits; the 64-bit one is only slightly more
complicated because it contains the x32 generation rule.
- Define __DISABLE_EXPORTS when building the vdso. This need seems to
have been masked by different ordering compile flags before.
- Change CONFIG_X86_64 to BUILD_VDSO32_64 in vdso32/system_call.S,
to make it compatible with including fake_32bit_build.h.
- The -fcf-protection= option was "leaking" from the kernel build,
for reasons that was not clear to me. Furthermore, several
distributions ship with it set to a default value other than
"-fcf-protection=none". Make it match the configuration options
for *user space*.
Note that this patch may seem large, but the vast majority of it is
simply code movement.
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://patch.msgid.link/20251216212606.1325678-4-hpa@zytor.com
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It is generally better to build tools in arch/x86/tools to keep host
cflags proliferation down, and to reduce makefile sequencing issues.
Move the vdso build tool vdso2c into arch/x86/tools in preparation for
refactoring the vdso makefiles.
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://patch.msgid.link/20251216212606.1325678-3-hpa@zytor.com
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The vdso .so files are named vdso*.so. These structures are binary
images and descriptions of these files, so it is more consistent for
them to have a naming that more directly mirrors the filenames.
It is also very slightly more compact (by one character...) and
simplifies the Makefile just a little bit.
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://patch.msgid.link/20251216212606.1325678-2-hpa@zytor.com
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sev_gmem_post_populate() needs to unmap the target vaddr after
copy_from_user() to the vaddr fails.
Fixes: dee5a47cc7a4 ("KVM: SEV: Add KVM_SEV_SNP_LAUNCH_UPDATE command")
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Michael Roth <michael.roth@amd.com>
Link: https://patch.msgid.link/20260108214622.1084057-2-michael.roth@amd.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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err is duplicated with errno, and never used; remove it.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Alex Shi <alexs@kernel.org>
Link: https://patch.msgid.link/20260107064009.15380-1-alexs@kernel.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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It can be used when we want to add virtio devices to UML while
it's up and running. Virtio devices can be added to UML using
the same syntax as the command line option:
(mconsole) config virtio_uml.device=<socket>:<virtio_id>[:<platform_id>]
Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Link: https://patch.msgid.link/20260106004259.1604736-1-tiwei.btw@antgroup.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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In seccomp mode, SIGCHLD serves as the child reaper IRQ. So, let's
handle it in the same way as other IRQ signals, including preventing
them from nesting with each other and allowing interrupted syscalls
to be automatically restarted.
Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Link: https://patch.msgid.link/20260106001228.1531146-3-tiwei.btw@antgroup.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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