[ Upstream commit 189ecdb3e112da703ac0699f4ec76aa78122f911 ] Snapshot the host's DEBUGCTL after disabling IRQs, as perf can toggle debugctl bits from IRQ context, e.g. when enabling/disabling events via smp_call_function_single(). Taking the snapshot (long) before IRQs are disabled could result in KVM effectively clobbering DEBUGCTL due to using a stale snapshot. Cc: stable@xxxxxxxxxxxxxxx Reviewed-and-tested-by: Ravi Bangoria <ravi.bangoria@xxxxxxx> Link: https://lore.kernel.org/r/20250227222411.3490595-6-seanjc@xxxxxxxxxx Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx> --- arch/x86/kvm/x86.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index ed16f97d1320..22a191a37e41 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4823,7 +4823,6 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) /* Save host pkru register if supported */ vcpu->arch.host_pkru = read_pkru(); - vcpu->arch.host_debugctl = get_debugctlmsr(); /* Apply any externally detected TSC adjustments (due to suspend) */ if (unlikely(vcpu->arch.tsc_offset_adjustment)) { @@ -10782,6 +10781,8 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) set_debugreg(0, 7); } + vcpu->arch.host_debugctl = get_debugctlmsr(); + guest_timing_enter_irqoff(); for (;;) { -- 2.51.0.rc1.163.g2494970778-goog
