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[99.254.144.39]) by smtp.gmail.com with ESMTPSA id ig4-20020a05622a6a4400b004120ae42859sm3863939qtb.90.2023.09.19.10.14.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 19 Sep 2023 10:14:11 -0700 (PDT) Date: Tue, 19 Sep 2023 13:14:09 -0400 From: Peter Xu To: Mattias Nissler Cc: qemu-devel@nongnu.org, john.levon@nutanix.com, stefanha@redhat.com, Richard Henderson , Elena Ufimtseva , "Michael S. Tsirkin" , Paolo Bonzini , Jagannathan Raman , David Hildenbrand , Marcel Apfelbaum , Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= Subject: Re: [PATCH v4 2/5] softmmu: Support concurrent bounce buffers Message-ID: References: <20230919160814.3343727-1-mnissler@rivosinc.com> <20230919160814.3343727-3-mnissler@rivosinc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20230919160814.3343727-3-mnissler@rivosinc.com> Received-SPF: pass client-ip=170.10.133.124; envelope-from=peterx@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_H3=0.001, RCVD_IN_MSPIKE_WL=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, Sep 19, 2023 at 09:08:10AM -0700, Mattias Nissler wrote: > @@ -3119,31 +3143,35 @@ void *address_space_map(AddressSpace *as, > void address_space_unmap(AddressSpace *as, void *buffer, hwaddr len, > bool is_write, hwaddr access_len) > { > - if (buffer != as->bounce.buffer) { > - MemoryRegion *mr; > - ram_addr_t addr1; > + MemoryRegion *mr; > + ram_addr_t addr1; > + > + mr = memory_region_from_host(buffer, &addr1); > + if (mr == NULL) { > + BounceBuffer *bounce = container_of(buffer, BounceBuffer, buffer); > + assert(bounce->magic == BOUNCE_BUFFER_MAGIC); > > - mr = memory_region_from_host(buffer, &addr1); > - assert(mr != NULL); > if (is_write) { > - invalidate_and_set_dirty(mr, addr1, access_len); > - } > - if (xen_enabled()) { > - xen_invalidate_map_cache_entry(buffer); > + address_space_write(as, bounce->addr, MEMTXATTRS_UNSPECIFIED, > + bounce->buffer, access_len); > } > - memory_region_unref(mr); > + > + memory_region_unref(bounce->mr); > + qatomic_sub(&as->bounce_buffer_size, bounce->len); > + /* Write bounce_buffer_size before reading map_client_list. */ > + smp_mb(); > + address_space_notify_map_clients(as); > + bounce->magic = ~BOUNCE_BUFFER_MAGIC; > + g_free(bounce); > return; > } > + > + if (xen_enabled()) { > + xen_invalidate_map_cache_entry(buffer); > + } > if (is_write) { > - address_space_write(as, as->bounce.addr, MEMTXATTRS_UNSPECIFIED, > - as->bounce.buffer, access_len); > - } > - qemu_vfree(as->bounce.buffer); > - as->bounce.buffer = NULL; > - memory_region_unref(as->bounce.mr); This line needs to be kept? > - /* Clear in_use before reading map_client_list. */ > - qatomic_set_mb(&as->bounce.in_use, false); > - address_space_notify_map_clients(as); > + invalidate_and_set_dirty(mr, addr1, access_len); > + } > } -- Peter Xu