From 7d611233b01613c866259d6e6f44c67f7f7eb2a3 Mon Sep 17 00:00:00 2001 From: Suravee Suthikulpanit Date: Wed, 6 May 2020 21:35:39 -0500 Subject: KVM: SVM: Disable AVIC before setting V_IRQ The commit 64b5bd270426 ("KVM: nSVM: ignore L1 interrupt window while running L2 with V_INTR_MASKING=1") introduced a WARN_ON, which checks if AVIC is enabled when trying to set V_IRQ in the VMCB for enabling irq window. The following warning is triggered because the requesting vcpu (to deactivate AVIC) does not get to process APICv update request for itself until the next #vmexit. WARNING: CPU: 0 PID: 118232 at arch/x86/kvm/svm/svm.c:1372 enable_irq_window+0x6a/0xa0 [kvm_amd] RIP: 0010:enable_irq_window+0x6a/0xa0 [kvm_amd] Call Trace: kvm_arch_vcpu_ioctl_run+0x6e3/0x1b50 [kvm] ? kvm_vm_ioctl_irq_line+0x27/0x40 [kvm] ? _copy_to_user+0x26/0x30 ? kvm_vm_ioctl+0xb3e/0xd90 [kvm] ? set_next_entity+0x78/0xc0 kvm_vcpu_ioctl+0x236/0x610 [kvm] ksys_ioctl+0x8a/0xc0 __x64_sys_ioctl+0x1a/0x20 do_syscall_64+0x58/0x210 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fixes by sending APICV update request to all other vcpus, and immediately update APIC for itself. Signed-off-by: Suravee Suthikulpanit Link: https://lkml.org/lkml/2020/5/2/167 Fixes: 64b5bd270426 ("KVM: nSVM: ignore L1 interrupt window while running L2 with V_INTR_MASKING=1") Message-Id: <1588818939-54264-1-git-send-email-suravee.suthikulpanit@amd.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/x86.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) (limited to 'arch/x86/kvm/x86.c') diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index ba8edf3b89f6..98176b80c481 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -8060,6 +8060,7 @@ EXPORT_SYMBOL_GPL(kvm_vcpu_update_apicv); */ void kvm_request_apicv_update(struct kvm *kvm, bool activate, ulong bit) { + struct kvm_vcpu *except; unsigned long old, new, expected; if (!kvm_x86_ops.check_apicv_inhibit_reasons || @@ -8084,7 +8085,17 @@ void kvm_request_apicv_update(struct kvm *kvm, bool activate, ulong bit) trace_kvm_apicv_update_request(activate, bit); if (kvm_x86_ops.pre_update_apicv_exec_ctrl) kvm_x86_ops.pre_update_apicv_exec_ctrl(kvm, activate); - kvm_make_all_cpus_request(kvm, KVM_REQ_APICV_UPDATE); + + /* + * Sending request to update APICV for all other vcpus, + * while update the calling vcpu immediately instead of + * waiting for another #VMEXIT to handle the request. + */ + except = kvm_get_running_vcpu(); + kvm_make_all_cpus_request_except(kvm, KVM_REQ_APICV_UPDATE, + except); + if (except) + kvm_vcpu_update_apicv(except); } EXPORT_SYMBOL_GPL(kvm_request_apicv_update); -- cgit v1.2.3