mirror of
https://github.com/raspberrypi/linux.git
synced 2025-12-06 01:49:46 +00:00
fd92bd3b44
Use a raw spinlock for vcpu_svm.ir_list_lock as the lock can be taken during schedule() via kvm_sched_out() => __avic_vcpu_put(), and "normal" spinlocks are sleepable locks when PREEMPT_RT=y. This fixes the following lockdep warning: ============================= [ BUG: Invalid wait context ] 6.12.0-146.1640_2124176644.el10.x86_64+debug #1 Not tainted ----------------------------- qemu-kvm/38299 is trying to lock: ff11000239725600 (&svm->ir_list_lock){....}-{3:3}, at: __avic_vcpu_put+0xfd/0x300 [kvm_amd] other info that might help us debug this: context-{5:5} 2 locks held by qemu-kvm/38299: #0: ff11000239723ba8 (&vcpu->mutex){+.+.}-{4:4}, at: kvm_vcpu_ioctl+0x240/0xe00 [kvm] #1: ff11000b906056d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2e/0x130 stack backtrace: CPU: 1 UID: 0 PID: 38299 Comm: qemu-kvm Kdump: loaded Not tainted 6.12.0-146.1640_2124176644.el10.x86_64+debug #1 PREEMPT(voluntary) Hardware name: AMD Corporation QUARTZ/QUARTZ, BIOS RQZ100AB 09/14/2023 Call Trace: <TASK> dump_stack_lvl+0x6f/0xb0 __lock_acquire+0x921/0xb80 lock_acquire.part.0+0xbe/0x270 _raw_spin_lock_irqsave+0x46/0x90 __avic_vcpu_put+0xfd/0x300 [kvm_amd] svm_vcpu_put+0xfa/0x130 [kvm_amd] kvm_arch_vcpu_put+0x48c/0x790 [kvm] kvm_sched_out+0x161/0x1c0 [kvm] prepare_task_switch+0x36b/0xf60 __schedule+0x4f7/0x1890 schedule+0xd4/0x260 xfer_to_guest_mode_handle_work+0x54/0xc0 vcpu_run+0x69a/0xa70 [kvm] kvm_arch_vcpu_ioctl_run+0xdc0/0x17e0 [kvm] kvm_vcpu_ioctl+0x39f/0xe00 [kvm] Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Link: https://patch.msgid.link/20251030194130.307900-1-mlevitsk@redhat.com [sean: massage changelog] Signed-off-by: Sean Christopherson <seanjc@google.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.