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Tue, 15 Apr 2025 04:52:11 -0700 (PDT) X-Google-Smtp-Source: AGHT+IFwlp36868LpQUjPHrMmCWFTFmEolm+hpK4MrvotqgJnYJioVbY20Idur2vLK4dOGO2BIKlVlW0lfPKLzHdynQ= X-Received: by 2002:a05:600c:3148:b0:43b:ca8c:fca3 with SMTP id 5b1f17b1804b1-43f9ad6ee73mr26833855e9.11.1744717931015; Tue, 15 Apr 2025 04:52:11 -0700 (PDT) MIME-Version: 1.0 References: <20250415061353.185589-1-clement.mathieu--drif@eviden.com> In-Reply-To: From: Paolo Bonzini Date: Tue, 15 Apr 2025 13:51:48 +0200 X-Gm-Features: ATxdqUHpN3hvvrWwnErNOggZHgGP3CHt5fnblaITMEuJzi51XGXFm0HTBrpaJDc Message-ID: Subject: Re: [PATCH] intel_iommu: Take the bql before registering a new address space To: CLEMENT MATHIEU--DRIF Cc: "qemu-devel@nongnu.org" , "jasowang@redhat.com" , "zhenzhong.duan@intel.com" , "kevin.tian@intel.com" , "yi.l.liu@intel.com" , "peterx@redhat.com" , "mst@redhat.com" Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Received-SPF: pass client-ip=170.10.133.124; envelope-from=pbonzini@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Tue, Apr 15, 2025 at 1:51=E2=80=AFPM CLEMENT MATHIEU--DRIF wrote: > On 15/04/2025 11:30 am, Paolo Bonzini wrote: > > Caution: External email. Do not open attachments or click links, unless > > this email comes from a known sender and you know the content is safe. > > > > > > On 4/15/25 08:18, CLEMENT MATHIEU--DRIF wrote: > >> Address space creation might end up being called without holding the > >> bql as it is exposed through the IOMMU ops. > >> > >> Signed-off-by: Clement Mathieu--Drif > > > > Please use a separate lock instead of the BQL. > > Hi Paolo, > > We need this particular lock because some of the functions we call > require the bql to be held. What functions do you need? > Is it a problem? It depends on the function. :) Paolo