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AJvYcCUhSwa/i45ACD/NhYRxCtduWLkjtKoLutsRcAr5Z3R/hJgLO33jmXsErkFulvZfqgwlLAM=@vger.kernel.org X-Gm-Message-State: AOJu0Yw4EuH9u+k/3js68mJudwcf2N/5PaiWFncux6YOOr+nE4uyRC4y TdZbLfKe6UcpLnL6eZ6MwSmsTX0J1Q5pFw4o5Lky6yLz1KoPFyab4uyS+NgExhDOL/S3sTEFxDj j0g== X-Google-Smtp-Source: AGHT+IHZhSXXubTpCFlOOnEIvHU467QNmKjXZoPNQezYYBYMwUyEsWt9k+iXgKJhh/FN2m03pEsubHOIrwo= X-Received: from pjyp13.prod.google.com ([2002:a17:90a:e70d:b0:2fc:2ee0:d38a]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:53c5:b0:2ee:8430:b831 with SMTP id 98e67ed59e1d1-3087bb3e7a6mr7256764a91.2.1745024910614; Fri, 18 Apr 2025 18:08:30 -0700 (PDT) Date: Fri, 18 Apr 2025 18:08:29 -0700 In-Reply-To: Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250417131945.109053-1-adrian.hunter@intel.com> <20250417131945.109053-2-adrian.hunter@intel.com> Message-ID: Subject: Re: [PATCH V2 1/1] KVM: TDX: Add sub-ioctl KVM_TDX_TERMINATE_VM From: Sean Christopherson To: Vishal Annapurve Cc: Adrian Hunter , pbonzini@redhat.com, mlevitsk@redhat.com, kvm@vger.kernel.org, rick.p.edgecombe@intel.com, kirill.shutemov@linux.intel.com, kai.huang@intel.com, reinette.chatre@intel.com, xiaoyao.li@intel.com, tony.lindgren@linux.intel.com, binbin.wu@linux.intel.com, isaku.yamahata@intel.com, linux-kernel@vger.kernel.org, yan.y.zhao@intel.com, chao.gao@intel.com Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable On Fri, Apr 18, 2025, Vishal Annapurve wrote: > On Thu, Apr 17, 2025 at 6:20=E2=80=AFAM Adrian Hunter wrote: > > > > ... > > +static int tdx_terminate_vm(struct kvm *kvm) > > +{ > > + int r =3D 0; > > + > > + guard(mutex)(&kvm->lock); > > + cpus_read_lock(); > > + > > + if (!kvm_trylock_all_vcpus(kvm)) { >=20 > Does this need to be a trylock variant? Is userspace expected to keep > retrying this operation indefinitely? Userspace is expected to not be stupid, i.e. not be doing things with vCPUs= when terminating the VM. This is already rather unpleasant, I'd rather not have= to think hard about what could go wrong if KVM has to wait on all vCPU mutexes= .