| Age | Commit message (Collapse) | Author | Files | Lines |
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Add support for CMPXCHG loops on userspace addresses. Provide both an
"unsafe" version for tight loops that do their own uaccess begin/end, as
well as a "safe" version for use cases where the CMPXCHG is not buried in
a loop, e.g. KVM will resume the guest instead of looping when emulation
of a guest atomic accesses fails the CMPXCHG.
Provide 8-byte versions for 32-bit kernels so that KVM can do CMPXCHG on
guest PAE PTEs, which are accessed via userspace addresses.
Guard the asm_volatile_goto() variation with CC_HAS_ASM_GOTO_TIED_OUTPUT,
the "+m" constraint fails on some compilers that otherwise support
CC_HAS_ASM_GOTO_OUTPUT.
Cc: stable@vger.kernel.org
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Co-developed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220202004945.2540433-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Add a config option to guard (future) usage of asm_volatile_goto() that
includes "tied outputs", i.e. "+" constraints that specify both an input
and output parameter. clang-13 has a bug[1] that causes compilation of
such inline asm to fail, and KVM wants to use a "+m" constraint to
implement a uaccess form of CMPXCHG[2]. E.g. the test code fails with
<stdin>:1:29: error: invalid operand in inline asm: '.long (${1:l}) - .'
int foo(int *x) { asm goto (".long (%l[bar]) - .\n": "+m"(*x) ::: bar); return *x; bar: return 0; }
^
<stdin>:1:29: error: unknown token in expression
<inline asm>:1:9: note: instantiated into assembly here
.long () - .
^
2 errors generated.
on clang-13, but passes on gcc (with appropriate asm goto support). The
bug is fixed in clang-14, but won't be backported to clang-13 as the
changes are too invasive/risky.
gcc also had a similar bug[3], fixed in gcc-11, where gcc failed to
account for its behavior of assigning two numbers to tied outputs (one
for input, one for output) when evaluating symbolic references.
[1] https://github.com/ClangBuiltLinux/linux/issues/1512
[2] https://lore.kernel.org/all/YfMruK8%2F1izZ2VHS@google.com
[3] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98096
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220202004945.2540433-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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If an SEV-ES guest requests termination, exit to userspace with
KVM_EXIT_SYSTEM_EVENT and a dedicated SEV_TERM type instead of -EINVAL
so that userspace can take appropriate action.
See AMD's GHCB spec section '4.1.13 Termination Request' for more details.
Suggested-by: Sean Christopherson <seanjc@google.com>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Peter Gonda <pgonda@google.com>
Reported-by: kernel test robot <lkp@intel.com>
Message-Id: <20220407210233.782250-1-pgonda@google.com>
[Add documentatino. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Clear the IDT vectoring field in vmcs12 on next VM-Exit due to a double
or triple fault. Per the SDM, a VM-Exit isn't considered to occur during
event delivery if the exit is due to an intercepted double fault or a
triple fault. Opportunistically move the default clearing (no event
"pending") into the helper so that it's more obvious that KVM does indeed
handle this case.
Note, the double fault case is worded rather wierdly in the SDM:
The original event results in a double-fault exception that causes the
VM exit directly.
Temporarily ignoring injected events, double faults can _only_ occur if
an exception occurs while attempting to deliver a different exception,
i.e. there's _always_ an original event. And for injected double fault,
while there's no original event, injected events are never subject to
interception.
Presumably the SDM is calling out that a the vectoring info will be valid
if a different exit occurs after a double fault, e.g. if a #PF occurs and
is intercepted while vectoring #DF, then the vectoring info will show the
double fault. In other words, the clause can simply be read as:
The VM exit is caused by a double-fault exception.
Fixes: 4704d0befb07 ("KVM: nVMX: Exiting from L2 to L1")
Cc: Chenyi Qiang <chenyi.qiang@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220407002315.78092-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Don't modify vmcs12 exit fields except EXIT_REASON and EXIT_QUALIFICATION
when performing a nested VM-Exit due to failed VM-Entry. Per the SDM,
only the two aformentioned fields are filled and "All other VM-exit
information fields are unmodified".
Fixes: 4704d0befb07 ("KVM: nVMX: Exiting from L2 to L1")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220407002315.78092-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Remove WARNs that sanity check that KVM never lets a triple fault for L2
escape and incorrectly end up in L1. In normal operation, the sanity
check is perfectly valid, but it incorrectly assumes that it's impossible
for userspace to induce KVM_REQ_TRIPLE_FAULT without bouncing through
KVM_RUN (which guarantees kvm_check_nested_state() will see and handle
the triple fault).
The WARN can currently be triggered if userspace injects a machine check
while L2 is active and CR4.MCE=0. And a future fix to allow save/restore
of KVM_REQ_TRIPLE_FAULT, e.g. so that a synthesized triple fault isn't
lost on migration, will make it trivially easy for userspace to trigger
the WARN.
Clearing KVM_REQ_TRIPLE_FAULT when forcibly leaving guest mode is
tempting, but wrong, especially if/when the request is saved/restored,
e.g. if userspace restores events (including a triple fault) and then
restores nested state (which may forcibly leave guest mode). Ignoring
the fact that KVM doesn't currently provide the necessary APIs, it's
userspace's responsibility to manage pending events during save/restore.
------------[ cut here ]------------
WARNING: CPU: 7 PID: 1399 at arch/x86/kvm/vmx/nested.c:4522 nested_vmx_vmexit+0x7fe/0xd90 [kvm_intel]
Modules linked in: kvm_intel kvm irqbypass
CPU: 7 PID: 1399 Comm: state_test Not tainted 5.17.0-rc3+ #808
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
RIP: 0010:nested_vmx_vmexit+0x7fe/0xd90 [kvm_intel]
Call Trace:
<TASK>
vmx_leave_nested+0x30/0x40 [kvm_intel]
vmx_set_nested_state+0xca/0x3e0 [kvm_intel]
kvm_arch_vcpu_ioctl+0xf49/0x13e0 [kvm]
kvm_vcpu_ioctl+0x4b9/0x660 [kvm]
__x64_sys_ioctl+0x83/0xb0
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x44/0xae
</TASK>
---[ end trace 0000000000000000 ]---
Fixes: cb6a32c2b877 ("KVM: x86: Handle triple fault in L2 without killing L1")
Cc: stable@vger.kernel.org
Cc: Chenyi Qiang <chenyi.qiang@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220407002315.78092-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Use static calls to improve kvm_pmu_ops performance, following the same
pattern and naming scheme used by kvm-x86-ops.h.
Here are the worst fenced_rdtsc() cycles numbers for the kvm_pmu_ops
functions that is most often called (up to 7 digits of calls) when running
a single perf test case in a guest on an ICX 2.70GHz host (mitigations=on):
| legacy | static call
------------------------------------------------------------
.pmc_idx_to_pmc | 1304840 | 994872 (+23%)
.pmc_is_enabled | 978670 | 1011750 (-3%)
.msr_idx_to_pmc | 47828 | 41690 (+12%)
.is_valid_msr | 28786 | 30108 (-4%)
Signed-off-by: Like Xu <likexu@tencent.com>
[sean: Handle static call updates in pmu.c, tweak changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220329235054.3534728-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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The pmu_ops should be moved to kvm_x86_init_ops and tagged as __initdata.
That'll save those precious few bytes, and more importantly make
the original ops unreachable, i.e. make it harder to sneak in post-init
modification bugs.
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Like Xu <likexu@tencent.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220329235054.3534728-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Replace the kvm_pmu_ops pointer in common x86 with an instance of the
struct to save one pointer dereference when invoking functions. Copy the
struct by value to set the ops during kvm_init().
Signed-off-by: Like Xu <likexu@tencent.com>
[sean: Move pmc_is_enabled(), make kvm_pmu_ops static]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220329235054.3534728-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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The kvm_ops_static_call_update() is defined in kvm_host.h. That's
completely unnecessary, it should have exactly one caller,
kvm_arch_hardware_setup(). Move the helper to x86.c and have it do the
actual memcpy() of the ops in addition to the static call updates. This
will also allow for cleanly giving kvm_pmu_ops static_call treatment.
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Like Xu <likexu@tencent.com>
[sean: Move memcpy() into the helper and rename accordingly]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220329235054.3534728-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Derive the mask of RWX bits reported on EPT violations from the mask of
RWX bits that are shoved into EPT entries; the layout is the same, the
EPT violation bits are simply shifted by three. Use the new shift and a
slight copy-paste of the mask derivation instead of completely open
coding the same to convert between the EPT entry bits and the exit
qualification when synthesizing a nested EPT Violation.
No functional change intended.
Cc: SU Hang <darcy.sh@antgroup.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220329030108.97341-3-darcy.sh@antgroup.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Using self-expressing macro definition EPT_VIOLATION_GVA_VALIDATION
and EPT_VIOLATION_GVA_TRANSLATED instead of 0x180
in FNAME(walk_addr_generic)().
Signed-off-by: SU Hang <darcy.sh@antgroup.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220329030108.97341-2-darcy.sh@antgroup.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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When the "nopv" command line parameter is used, it should not waste
memory for kvmclock.
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Message-Id: <1646727529-11774-1-git-send-email-wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Remove redundant parentheses.
Signed-off-by: Peng Hao <flyingpeng@tencent.com>
Message-Id: <20220228030902.88465-1-flyingpeng@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Adjust the field pkru_mask to the back of direct_map to make up 8-byte
alignment.This reduces the size of kvm_mmu by 8 bytes.
Signed-off-by: Peng Hao <flyingpeng@tencent.com>
Message-Id: <20220228030749.88353-1-flyingpeng@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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+WARNING: Possible comma where semicolon could be used
+#397: FILE: tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c:700:
++ tmr.type = KVM_XEN_VCPU_ATTR_TYPE_TIMER,
++ vcpu_ioctl(vm, VCPU_ID, KVM_XEN_VCPU_GET_ATTR, &tmr);
Fixes: 25eaeebe710c ("KVM: x86/xen: Add self tests for KVM_XEN_HVM_CONFIG_EVTCHN_SEND")
Signed-off-by: Like Xu <likexu@tencent.com>
Message-Id: <20220406063715.55625-4-likexu@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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The header lapic.h is included more than once, remove one of them.
Signed-off-by: Like Xu <likexu@tencent.com>
Message-Id: <20220406063715.55625-2-likexu@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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The following WARN is triggered from kvm_vm_ioctl_set_clock():
WARNING: CPU: 10 PID: 579353 at arch/x86/kvm/../../../virt/kvm/kvm_main.c:3161 mark_page_dirty_in_slot+0x6c/0x80 [kvm]
...
CPU: 10 PID: 579353 Comm: qemu-system-x86 Tainted: G W O 5.16.0.stable #20
Hardware name: LENOVO 20UF001CUS/20UF001CUS, BIOS R1CET65W(1.34 ) 06/17/2021
RIP: 0010:mark_page_dirty_in_slot+0x6c/0x80 [kvm]
...
Call Trace:
<TASK>
? kvm_write_guest+0x114/0x120 [kvm]
kvm_hv_invalidate_tsc_page+0x9e/0xf0 [kvm]
kvm_arch_vm_ioctl+0xa26/0xc50 [kvm]
? schedule+0x4e/0xc0
? __cond_resched+0x1a/0x50
? futex_wait+0x166/0x250
? __send_signal+0x1f1/0x3d0
kvm_vm_ioctl+0x747/0xda0 [kvm]
...
The WARN was introduced by commit 03c0304a86bc ("KVM: Warn if
mark_page_dirty() is called without an active vCPU") but the change seems
to be correct (unlike Hyper-V TSC page update mechanism). In fact, there's
no real need to actually write to guest memory to invalidate TSC page, this
can be done by the first vCPU which goes through kvm_guest_time_update().
Reported-by: Maxim Levitsky <mlevitsk@redhat.com>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20220407201013.963226-1-vkuznets@redhat.com>
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Since current AVIC implementation cannot support encrypted memory,
inhibit AVIC for SEV-enabled guest.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Message-Id: <20220408133710.54275-1-suravee.suthikulpanit@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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+new file mode 100644
+WARNING: Missing or malformed SPDX-License-Identifier tag in line 1
+#27: FILE: Documentation/virt/kvm/x86/errata.rst:1:
Opportunistically update all other non-added KVM documents and
remove a new extra blank line at EOF for x86/errata.rst.
Signed-off-by: Like Xu <likexu@tencent.com>
Message-Id: <20220406063715.55625-5-likexu@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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The tsc_scaling_sync's binary should be present in the .gitignore
file for the git to ignore it.
Signed-off-by: Like Xu <likexu@tencent.com>
Message-Id: <20220406063715.55625-3-likexu@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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vcpu_fp uses the riscv_isa_extension mechanism which gets
defined in hwcap.h but doesn't include that head file.
While it seems to work in most cases, in certain conditions
this can lead to build failures like
../arch/riscv/kvm/vcpu_fp.c: In function ‘kvm_riscv_vcpu_fp_reset’:
../arch/riscv/kvm/vcpu_fp.c:22:13: error: implicit declaration of function ‘riscv_isa_extension_available’ [-Werror=implicit-function-declaration]
22 | if (riscv_isa_extension_available(&isa, f) ||
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../arch/riscv/kvm/vcpu_fp.c:22:49: error: ‘f’ undeclared (first use in this function)
22 | if (riscv_isa_extension_available(&isa, f) ||
Fix this by simply including the necessary header.
Fixes: 0a86512dc113 ("RISC-V: KVM: Factor-out FP virtualization into separate
sources")
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Anup Patel <anup@brainfault.org>
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The guest_hang() function is used as the default exception handler
for various KVM selftests applications by setting it's address in
the vstvec CSR. The vstvec CSR requires exception handler base address
to be at least 4-byte aligned so this patch fixes alignment of the
guest_hang() function.
Fixes: 3e06cdf10520 ("KVM: selftests: Add initial support for RISC-V
64-bit")
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Tested-by: Mayuresh Chitale <mchitale@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
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Supporting hardware updates of PTE A and D bits is optional for any
RISC-V implementation so current software strategy is to always set
these bits in both G-stage (hypervisor) and VS-stage (guest kernel).
If PTE A and D bits are not set by software (hypervisor or guest)
then RISC-V implementations not supporting hardware updates of these
bits will cause traps even for perfectly valid PTEs.
Based on above explanation, the VS-stage page table created by various
KVM selftest applications is not correct because PTE A and D bits are
not set. This patch fixes VS-stage page table programming of PTE A and
D bits for KVM selftests.
Fixes: 3e06cdf10520 ("KVM: selftests: Add initial support for RISC-V
64-bit")
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Tested-by: Mayuresh Chitale <mchitale@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
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We might have RISC-V systems (such as QEMU) where VMID is not part
of the TLB entry tag so these systems will have to flush all TLB
entries upon any change in hgatp.VMID.
Currently, we zero-out hgatp CSR in kvm_arch_vcpu_put() and we
re-program hgatp CSR in kvm_arch_vcpu_load(). For above described
systems, this will flush all TLB entries whenever VCPU exits to
user-space hence reducing performance.
This patch fixes above described performance issue by not clearing
hgatp CSR in kvm_arch_vcpu_put().
Fixes: 34bde9d8b9e6 ("RISC-V: KVM: Implement VCPU world-switch")
Cc: stable@vger.kernel.org
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
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In order to correctly destroy a VM, all references to the VM must be
freed. The arch_timer selftest creates a VGIC for the guest, which
itself holds a reference to the VM.
Close the GIC FD when cleaning up a VM.
Signed-off-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220406235615.1447180-4-oupton@google.com
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dirty_log_perf_test instantiates a VGICv3 for the guest (if supported by
hardware) to reduce the overhead of guest exits. However, the test does
not actually close the GIC fd when cleaning up the VM between test
iterations, meaning that the VM is never actually destroyed in the
kernel.
While this is generally a bad idea, the bug was detected from the kernel
spewing about duplicate debugfs entries as subsequent VMs happen to
reuse the same FD even though the debugfs directory is still present.
Abstract away the notion of setup/cleanup of the GIC FD from the test
by creating arch-specific helpers for test setup/cleanup. Close the GIC
FD on VM cleanup and do nothing for the other architectures.
Fixes: c340f7899af6 ("KVM: selftests: Add vgic initialization for dirty log perf test for ARM")
Reviewed-by: Jing Zhang <jingzhangos@google.com>
Signed-off-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220406235615.1447180-3-oupton@google.com
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Unfortunately, there is no guarantee that KVM was able to instantiate a
debugfs directory for a particular VM. To that end, KVM shouldn't even
attempt to create new debugfs files in this case. If the specified
parent dentry is NULL, debugfs_create_file() will instantiate files at
the root of debugfs.
For arm64, it is possible to create the vgic-state file outside of a
VM directory, the file is not cleaned up when a VM is destroyed.
Nonetheless, the corresponding struct kvm is freed when the VM is
destroyed.
Nip the problem in the bud for all possible errant debugfs file
creations by initializing kvm->debugfs_dentry to -ENOENT. In so doing,
debugfs_create_file() will fail instead of creating the file in the root
directory.
Cc: stable@kernel.org
Fixes: 929f45e32499 ("kvm: no need to check return value of debugfs_create functions")
Signed-off-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220406235615.1447180-2-oupton@google.com
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When testing a kernel with commit a5905d6af492 ("KVM: arm64:
Allow SMCCC_ARCH_WORKAROUND_3 to be discovered and migrated")
get-reg-list output
vregs: Number blessed registers: 234
vregs: Number registers: 238
vregs: There are 1 new registers.
Consider adding them to the blessed reg list with the following lines:
KVM_REG_ARM_FW_REG(3),
vregs: PASS
...
That output inspired two changes: 1) add the new register to the
blessed list and 2) explain why "Number registers" is actually four
larger than "Number blessed registers" (on the system used for
testing), even though only one register is being stated as new.
The reason is that some registers are host dependent and they get
filtered out when comparing with the blessed list. The system
used for the test apparently had three filtered registers.
Signed-off-by: Andrew Jones <drjones@redhat.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220316125129.392128-1-drjones@redhat.com
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kvm_vcpu_release() will call kvm_dirty_ring_free(), freeing
ring->dirty_gfns and setting it to NULL. Afterwards, it calls
kvm_arch_vcpu_destroy().
However, if closing the file descriptor races with KVM_RUN in such away
that vcpu->arch.st.preempted == 0, the following call stack leads to a
NULL pointer dereference in kvm_dirty_run_push():
mark_page_dirty_in_slot+0x192/0x270 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3171
kvm_steal_time_set_preempted arch/x86/kvm/x86.c:4600 [inline]
kvm_arch_vcpu_put+0x34e/0x5b0 arch/x86/kvm/x86.c:4618
vcpu_put+0x1b/0x70 arch/x86/kvm/../../../virt/kvm/kvm_main.c:211
vmx_free_vcpu+0xcb/0x130 arch/x86/kvm/vmx/vmx.c:6985
kvm_arch_vcpu_destroy+0x76/0x290 arch/x86/kvm/x86.c:11219
kvm_vcpu_destroy arch/x86/kvm/../../../virt/kvm/kvm_main.c:441 [inline]
The fix is to release the dirty page ring after kvm_arch_vcpu_destroy
has run.
Reported-by: Qiuhao Li <qiuhao@sysec.org>
Reported-by: Gaoning Pan <pgn@zju.edu.cn>
Reported-by: Yongkang Jia <kangel@zju.edu.cn>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Introduce a test for aarch64 that ensures non-mixed-width vCPUs
(all 64bit vCPUs or all 32bit vcPUs) can be configured, and
mixed-width vCPUs cannot be configured.
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Reiji Watanabe <reijiw@google.com>
Reviewed-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220329031924.619453-3-reijiw@google.com
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KVM allows userspace to configure either all EL1 32bit or 64bit vCPUs
for a guest. At vCPU reset, vcpu_allowed_register_width() checks
if the vcpu's register width is consistent with all other vCPUs'.
Since the checking is done even against vCPUs that are not initialized
(KVM_ARM_VCPU_INIT has not been done) yet, the uninitialized vCPUs
are erroneously treated as 64bit vCPU, which causes the function to
incorrectly detect a mixed-width VM.
Introduce KVM_ARCH_FLAG_EL1_32BIT and KVM_ARCH_FLAG_REG_WIDTH_CONFIGURED
bits for kvm->arch.flags. A value of the EL1_32BIT bit indicates that
the guest needs to be configured with all 32bit or 64bit vCPUs, and
a value of the REG_WIDTH_CONFIGURED bit indicates if a value of the
EL1_32BIT bit is valid (already set up). Values in those bits are set at
the first KVM_ARM_VCPU_INIT for the guest based on KVM_ARM_VCPU_EL1_32BIT
configuration for the vCPU.
Check vcpu's register width against those new bits at the vcpu's
KVM_ARM_VCPU_INIT (instead of against other vCPUs' register width).
Fixes: 66e94d5cafd4 ("KVM: arm64: Prevent mixed-width VM creation")
Signed-off-by: Reiji Watanabe <reijiw@google.com>
Reviewed-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220329031924.619453-2-reijiw@google.com
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Remove unnecessary casts.
Signed-off-by: Yu Zhe <yuzhe@nfschina.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220329102059.268983-1-yuzhe@nfschina.com
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It is possible to take a stage-2 permission fault on a page larger than
PAGE_SIZE. For example, when running a guest backed by 2M HugeTLB, KVM
eagerly maps at the largest possible block size. When dirty logging is
enabled on a memslot, KVM does *not* eagerly split these 2M stage-2
mappings and instead clears the write bit on the pte.
Since dirty logging is always performed at PAGE_SIZE granularity, KVM
lazily splits these 2M block mappings down to PAGE_SIZE in the stage-2
fault handler. This operation must be done under the write lock. Since
commit f783ef1c0e82 ("KVM: arm64: Add fast path to handle permission
relaxation during dirty logging"), the stage-2 fault handler
conditionally takes the read lock on permission faults with dirty
logging enabled. To that end, it is possible to split a 2M block mapping
while only holding the read lock.
The problem is demonstrated by running kvm_page_table_test with 2M
anonymous HugeTLB, which splats like so:
WARNING: CPU: 5 PID: 15276 at arch/arm64/kvm/hyp/pgtable.c:153 stage2_map_walk_leaf+0x124/0x158
[...]
Call trace:
stage2_map_walk_leaf+0x124/0x158
stage2_map_walker+0x5c/0xf0
__kvm_pgtable_walk+0x100/0x1d4
__kvm_pgtable_walk+0x140/0x1d4
__kvm_pgtable_walk+0x140/0x1d4
kvm_pgtable_walk+0xa0/0xf8
kvm_pgtable_stage2_map+0x15c/0x198
user_mem_abort+0x56c/0x838
kvm_handle_guest_abort+0x1fc/0x2a4
handle_exit+0xa4/0x120
kvm_arch_vcpu_ioctl_run+0x200/0x448
kvm_vcpu_ioctl+0x588/0x664
__arm64_sys_ioctl+0x9c/0xd4
invoke_syscall+0x4c/0x144
el0_svc_common+0xc4/0x190
do_el0_svc+0x30/0x8c
el0_svc+0x28/0xcc
el0t_64_sync_handler+0x84/0xe4
el0t_64_sync+0x1a4/0x1a8
Fix the issue by only acquiring the read lock if the guest faulted on a
PAGE_SIZE granule w/ dirty logging enabled. Add a WARN to catch locking
bugs in future changes.
Fixes: f783ef1c0e82 ("KVM: arm64: Add fast path to handle permission relaxation during dirty logging")
Cc: Jing Zhang <jingzhangos@google.com>
Signed-off-by: Oliver Upton <oupton@google.com>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220401194652.950240-1-oupton@google.com
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We already sanitize the guest's PSCI version when it is being written by
userspace, rejecting unsupported version numbers. Additionally, the
'minor' parameter to kvm_psci_1_x_call() is a constant known at compile
time for all callsites.
Though it is benign, the additional check against the
PSCI kvm_psci_1_x_call() is unnecessary and likely to be missed the next
time KVM raises its maximum PSCI version. Drop the check altogether and
rely on sanitization when the PSCI version is set by userspace.
No functional change intended.
Signed-off-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220322183538.2757758-4-oupton@google.com
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The SMCCC does not allow the SMC64 calling convention to be used from
AArch32. While KVM checks to see if the calling convention is allowed in
PSCI_1_0_FN_PSCI_FEATURES, it does not actually prevent calls to
unadvertised PSCI v1.0+ functions.
Hoist the check to see if the requested function is allowed into
kvm_psci_call(), thereby preventing SMC64 calls from AArch32 for all
PSCI versions.
Fixes: d43583b890e7 ("KVM: arm64: Expose PSCI SYSTEM_RESET2 call to the guest")
Acked-by: Will Deacon <will@kernel.org>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220322183538.2757758-3-oupton@google.com
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The only valid calling SMC calling convention from an AArch32 state is
SMC32. Disallow any PSCI function that sets the SMC64 function ID bit
when called from AArch32 rather than comparing against known SMC64 PSCI
functions.
Note that without this change KVM advertises the SMC64 flavor of
SYSTEM_RESET2 to AArch32 guests.
Fixes: d43583b890e7 ("KVM: arm64: Expose PSCI SYSTEM_RESET2 call to the guest")
Acked-by: Will Deacon <will@kernel.org>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220322183538.2757758-2-oupton@google.com
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Add missing line break separator between literal block and description
of KVM_EXIT_RISCV_SBI.
This fixes:
</path/to/linux>/Documentation/virt/kvm/api.rst:6118: WARNING: Literal block ends without a blank line; unexpected unindent.
Fixes: da40d85805937d (RISC-V: KVM: Document RISC-V specific parts of KVM API, 2021-09-27)
Cc: Anup Patel <anup.patel@wdc.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-riscv@lists.infradead.org
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Message-Id: <20220403065735.23859-1-bagasdotme@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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All work currently pending will be done first by calling destroy_workqueue,
so there is unnecessary to flush it explicitly.
Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Lv Ruyi <lv.ruyi@zte.com.cn>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220401083530.2407703-1-lv.ruyi@zte.com.cn>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Resolve nx_huge_pages to true/false when kvm.ko is loaded, leaving it as
-1 is technically undefined behavior when its value is read out by
param_get_bool(), as boolean values are supposed to be '0' or '1'.
Alternatively, KVM could define a custom getter for the param, but the
auto value doesn't depend on the vendor module in any way, and printing
"auto" would be unnecessarily unfriendly to the user.
In addition to fixing the undefined behavior, resolving the auto value
also fixes the scenario where the auto value resolves to N and no vendor
module is loaded. Previously, -1 would result in Y being printed even
though KVM would ultimately disable the mitigation.
Rename the existing MMU module init/exit helpers to clarify that they're
invoked with respect to the vendor module, and add comments to document
why KVM has two separate "module init" flows.
=========================================================================
UBSAN: invalid-load in kernel/params.c:320:33
load of value 255 is not a valid value for type '_Bool'
CPU: 6 PID: 892 Comm: tail Not tainted 5.17.0-rc3+ #799
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
Call Trace:
<TASK>
dump_stack_lvl+0x34/0x44
ubsan_epilogue+0x5/0x40
__ubsan_handle_load_invalid_value.cold+0x43/0x48
param_get_bool.cold+0xf/0x14
param_attr_show+0x55/0x80
module_attr_show+0x1c/0x30
sysfs_kf_seq_show+0x93/0xc0
seq_read_iter+0x11c/0x450
new_sync_read+0x11b/0x1a0
vfs_read+0xf0/0x190
ksys_read+0x5f/0xe0
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x44/0xae
</TASK>
=========================================================================
Fixes: b8e8c8303ff2 ("kvm: mmu: ITLB_MULTIHIT mitigation")
Cc: stable@vger.kernel.org
Reported-by: Bruno Goncalves <bgoncalv@redhat.com>
Reported-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220331221359.3912754-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Add resched to avoid warning from sev_clflush_pages() with large number
of pages.
Signed-off-by: Peter Gonda <pgonda@google.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Message-Id: <20220330164306.2376085-1-pgonda@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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This reverts commit 7dabfa2bc4803eed83d6f22bd6f045495f40636b. There are
multiple reports that this breaks boot on various systems. The common
theme is that orphan clks are having rates set on them when that isn't
expected. Let's revert it out for now so that -rc1 boots.
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reported-by: Tony Lindgren <tony@atomide.com>
Reported-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Link: https://lore.kernel.org/r/366a0232-bb4a-c357-6aa8-636e398e05eb@samsung.com
Cc: Maxime Ripard <maxime@cerno.tech>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20220403022818.39572-1-sboyd@kernel.org
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This log message was accidentally chopped off.
I was wondering why this happened, but checking the ML log, Mark
precisely followed my suggestion [1].
I just used "..." because I was too lazy to type the sentence fully.
Sorry for the confusion.
[1]: https://lore.kernel.org/all/CAK7LNAR6bXXk9-ZzZYpTqzFqdYbQsZHmiWspu27rtsFxvfRuVA@mail.gmail.com/
Fixes: 4a6795933a89 ("kbuild: modpost: Explicitly warn about unprototyped symbols")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
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This reverts commit 6d35d04a9e18990040e87d2bbf72689252669d54.
Both Gabriel and Borislav report that this commit casues a regression
with nbd:
sysfs: cannot create duplicate filename '/dev/block/43:0'
Revert it before 5.18-rc1 and we'll investigage this separately in
due time.
Link: https://lore.kernel.org/all/YkiJTnFOt9bTv6A2@zn.tnic/
Reported-by: Gabriel L. Somlo <somlo@cmu.edu>
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Commit 7ea1a0124b6d ("watch_queue: Free the alloc bitmap when the
watch_queue is torn down") took care of the bitmap, but not the page
array.
BUG: memory leak
unreferenced object 0xffff88810d9bc140 (size 32):
comm "syz-executor335", pid 3603, jiffies 4294946994 (age 12.840s)
hex dump (first 32 bytes):
40 a7 40 04 00 ea ff ff 00 00 00 00 00 00 00 00 @.@.............
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
kmalloc_array include/linux/slab.h:621 [inline]
kcalloc include/linux/slab.h:652 [inline]
watch_queue_set_size+0x12f/0x2e0 kernel/watch_queue.c:251
pipe_ioctl+0x82/0x140 fs/pipe.c:632
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__x64_sys_ioctl+0xfc/0x140 fs/ioctl.c:860
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
Reported-by: syzbot+25ea042ae28f3888727a@syzkaller.appspotmail.com
Fixes: c73be61cede5 ("pipe: Add general notification queue support")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Jann Horn <jannh@google.com>
Link: https://lore.kernel.org/r/20220322004654.618274-1-eric.dumazet@gmail.com/
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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After being merged, user_events become more visible to a wider audience
that have concerns with the current API.
It is too late to fix this for this release, but instead of a full
revert, just mark it as BROKEN (which prevents it from being selected in
make config). Then we can work finding a better API. If that fails,
then it will need to be completely reverted.
To not have the code silently bitrot, still allow building it with
COMPILE_TEST.
And to prevent the uapi header from being installed, then later changed,
and then have an old distro user space see the old version, move the
header file out of the uapi directory.
Surround the include with CONFIG_COMPILE_TEST to the current location,
but when the BROKEN tag is taken off, it will use the uapi directory,
and fail to compile. This is a good way to remind us to move the header
back.
Link: https://lore.kernel.org/all/20220330155835.5e1f6669@gandalf.local.home
Link: https://lkml.kernel.org/r/20220330201755.29319-1-mathieu.desnoyers@efficios.com
Suggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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While user_events API is under development and has been marked for broken
to not let the API become fixed, move the header file out of the uapi
directory. This is to prevent it from being installed, then later changed,
and then have an old distro user space update with a new kernel, where
applications see the user_events being available, but the old header is in
place, and then they get compiled incorrectly.
Also, surround the include with CONFIG_COMPILE_TEST to the current
location, but when the BROKEN tag is taken off, it will use the uapi
directory, and fail to compile. This is a good way to remind us to move
the header back.
Link: https://lore.kernel.org/all/20220330155835.5e1f6669@gandalf.local.home
Link: https://lkml.kernel.org/r/20220330201755.29319-1-mathieu.desnoyers@efficios.com
Link: https://lkml.kernel.org/r/20220401143903.188384f3@gandalf.local.home
Suggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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ftrace_graph_is_dead() is used on hot paths, it just reads a variable
in memory and is not worth suffering function call constraints.
For instance, at entry of prepare_ftrace_return(), inlining it avoids
saving prepare_ftrace_return() parameters to stack and restoring them
after calling ftrace_graph_is_dead().
While at it using a static branch is even more performant and is
rather well adapted considering that the returned value will almost
never change.
Inline ftrace_graph_is_dead() and replace 'kill_ftrace_graph' bool
by a static branch.
The performance improvement is noticeable.
Link: https://lkml.kernel.org/r/e0411a6a0ed3eafff0ad2bc9cd4b0e202b4617df.1648623570.git.christophe.leroy@csgroup.eu
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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After being merged, user_events become more visible to a wider audience
that have concerns with the current API. It is too late to fix this for
this release, but instead of a full revert, just mark it as BROKEN (which
prevents it from being selected in make config). Then we can work finding
a better API. If that fails, then it will need to be completely reverted.
Link: https://lore.kernel.org/all/2059213643.196683.1648499088753.JavaMail.zimbra@efficios.com/
Link: https://lkml.kernel.org/r/20220330155835.5e1f6669@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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Peter Zijlstra
Sean Christopherson
Peter Gonda
Like Xu
SU Hang
Wanpeng Li
Peng Hao
Like Xu
Vitaly Kuznetsov
Suravee Suthikulpanit
Heiko Stuebner
Anup Patel
Oliver Upton
Andrew Jones
Paolo Bonzini
Reiji Watanabe
Yu Zhe
Bagas Sanjaya
Lv Ruyi
Linus Torvalds
Stephen Boyd
Masahiro Yamada
Jens Axboe
Eric Dumazet
Steven Rostedt (Google)
Christophe Leroy