linux/arch/x86/kvm
David Woodhouse 7a36d68065 KVM: x86/xen: fix recursive deadlock in timer injection
The fast-path timer delivery introduced a recursive locking deadlock
when userspace configures a timer which has already expired and is
delivered immediately. The call to kvm_xen_inject_timer_irqs() can
call to kvm_xen_set_evtchn() which may take kvm->arch.xen.xen_lock,
which is already held in kvm_xen_vcpu_get_attr().

 ============================================
 WARNING: possible recursive locking detected
 6.8.0-smp--5e10b4d51d77-drs #232 Tainted: G           O
 --------------------------------------------
 xen_shinfo_test/250013 is trying to acquire lock:
 ffff938c9930cc30 (&kvm->arch.xen.xen_lock){+.+.}-{3:3}, at: kvm_xen_set_evtchn+0x74/0x170 [kvm]

 but task is already holding lock:
 ffff938c9930cc30 (&kvm->arch.xen.xen_lock){+.+.}-{3:3}, at: kvm_xen_vcpu_get_attr+0x38/0x250 [kvm]

Now that the gfn_to_pfn_cache has its own self-sufficient locking, its
callers no longer need to ensure serialization, so just stop taking
kvm->arch.xen.xen_lock from kvm_xen_set_evtchn().

Fixes: 77c9b9dea4 ("KVM: x86/xen: Use fast path for Xen timer delivery")
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
Link: https://lore.kernel.org/r/20240227115648.3104-6-dwmw2@infradead.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
2024-03-04 16:22:39 -08:00
..
mmu Generic: 2024-01-17 13:03:37 -08:00
svm Generic: 2024-01-17 13:03:37 -08:00
vmx Generic: 2024-01-17 13:03:37 -08:00
.gitignore KVM: x86: use a separate asm-offsets.c file 2022-11-09 12:10:17 -05:00
cpuid.c Generic: 2024-01-17 13:03:37 -08:00
cpuid.h KVM: x86: Use KVM-governed feature framework to track "LAM enabled" 2023-11-28 17:54:09 -08:00
debugfs.c LoongArch KVM changes for v6.8 2024-01-02 13:16:29 -05:00
emulate.c KVM: x86: Introduce get_untagged_addr() in kvm_x86_ops and call it in emulator 2023-11-28 17:54:06 -08:00
fpu.h
governed_features.h KVM: x86: Use KVM-governed feature framework to track "LAM enabled" 2023-11-28 17:54:09 -08:00
hyperv.c KVM: x86: Give a hint when Win2016 might fail to boot due to XSAVES erratum 2024-01-31 16:21:00 -05:00
hyperv.h KVM: x86: Give a hint when Win2016 might fail to boot due to XSAVES erratum 2024-01-31 16:21:00 -05:00
i8254.c KVM: x86: Unify pr_fmt to use module name for all KVM modules 2022-12-29 15:47:35 -05:00
i8254.h KVM: x86: PIT: Preserve state of speaker port data bit 2022-06-08 13:06:20 -04:00
i8259.c KVM: x86: Fix poll command 2023-06-01 13:44:13 -07:00
ioapic.c KVM: x86/ioapic: Resample the pending state of an IRQ when unmasking 2023-03-27 10:13:28 -04:00
ioapic.h x86/kvm: remove unused ack_notifier callbacks 2021-11-18 07:05:57 -05:00
irq_comm.c KVM: x86: Make Hyper-V emulation optional 2023-12-07 09:34:57 -08:00
irq.c KVM: x86/xen: Remove unneeded xen context from kvm_arch when !CONFIG_KVM_XEN 2023-12-07 09:33:42 -08:00
irq.h x86/kvm: remove unused ack_notifier callbacks 2021-11-18 07:05:57 -05:00
Kconfig kvm: replace __KVM_HAVE_READONLY_MEM with Kconfig symbol 2024-02-08 08:41:06 -05:00
kvm_cache_regs.h KVM: x86: Add helpers to query individual CR0/CR4 bits 2023-03-22 10:10:53 -07:00
kvm_emulate.h KVM: x86: Introduce get_untagged_addr() in kvm_x86_ops and call it in emulator 2023-11-28 17:54:06 -08:00
kvm_onhyperv.c KVM: x86/mmu: Move filling of Hyper-V's TLB range struct into Hyper-V code 2023-04-10 15:17:29 -07:00
kvm_onhyperv.h KVM: x86: Move Hyper-V partition assist page out of Hyper-V emulation context 2023-12-07 09:34:01 -08:00
kvm-asm-offsets.c KVM: SVM: move MSR_IA32_SPEC_CTRL save/restore to assembly 2022-11-09 12:25:53 -05:00
lapic.c KVM: x86/xen: inject vCPU upcall vector when local APIC is enabled 2024-03-04 16:22:36 -08:00
lapic.h KVM: x86: Split out logic to generate "readable" APIC regs mask to helper 2023-01-24 10:04:35 -08:00
Makefile KVM: x86: Make Hyper-V emulation optional 2023-12-07 09:34:57 -08:00
mmu.h KVM: x86: Use KVM-governed feature framework to track "LAM enabled" 2023-11-28 17:54:09 -08:00
mtrr.c KVM: x86/mmu: Zap SPTEs on MTRR update iff guest MTRRs are honored 2023-10-09 14:35:14 -07:00
pmu.c KVM: x86/pmu: Track emulated counter events instead of previous counter 2023-11-30 12:52:55 -08:00
pmu.h KVM: x86/pmu: Track emulated counter events instead of previous counter 2023-11-30 12:52:55 -08:00
reverse_cpuid.h KVM: x86: Use a switch statement and macros in __feature_translate() 2023-11-30 12:27:02 -08:00
smm.c KVM: x86: Remove redundant vcpu->arch.cr0 assignments 2023-09-27 12:57:48 -07:00
smm.h KVM: x86: smm: preserve interrupt shadow in SMRAM 2022-11-09 12:31:26 -05:00
trace.h KVM: x86/xen: Add CPL to Xen hypercall tracepoint 2022-11-28 13:31:01 -05:00
tss.h
x86.c KVM: x86/xen: improve accuracy of Xen timers 2024-03-04 16:22:32 -08:00
x86.h KVM: x86/xen: improve accuracy of Xen timers 2024-03-04 16:22:32 -08:00
xen.c KVM: x86/xen: fix recursive deadlock in timer injection 2024-03-04 16:22:39 -08:00
xen.h KVM: x86/xen: inject vCPU upcall vector when local APIC is enabled 2024-03-04 16:22:36 -08:00