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([93.140.16.93]) by smtp.googlemail.com with ESMTPSA id ffacd0b85a97d-436297450b4sm514079f8f.34.2026.02.05.11.58.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 05 Feb 2026 11:58:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1770321538; x=1770926338; darn=nongnu.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=3w+4r91XUMpNZ+u0m8QgKhjEv84szY9BFvzEKdmRv4w=; b=Nr8bFFPz3FfH+ZRFcNov9KL66+302VeS/QAHmsdFyHAg6ljcbZlY4TnFapMMJ2bm2v EZFGlsgGC+3VNbe7k6zq7spoTtynlFjNAEul5pEtFEJ1m7GYhwRskme1t02HlxrbLdwB iyHoc1Y/iN43GHoq54+pEnFQ2KmBrEzQ0X0GnnEcSBjWHZu4isQOwpmlHmKKyYX7jjUh pAKVDGnMR5YviMGFRpUlS1235HGjFgjCwiTGb/SWbZFO4z1oUJ8Sf2l/K0M44Mz1ufph oB9Q2+RTAdOIzLy8g6ICwSqbjGXC2VvZHte9GH7XZUpufenmKFQ39OsEfHTOAM+mOpk6 N3jw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1770321538; x=1770926338; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=3w+4r91XUMpNZ+u0m8QgKhjEv84szY9BFvzEKdmRv4w=; b=AOfE7Pj6ry2Mgjr8RjaJFeETz02/Hg2pg2/M51FdVPTUTBi9fsPrDS4895XR4COQ7k m7uuyBwqkFqKqDcMxchqyvGTMl2dvM5Dvo81Ok9c1rwfEcoISO0Lel10FDgzD6zgn6bR ehJLmtsv7cbmzbumVdUh8Jw2CGmt7++fgvC/JTgnuG+LF6hP+QNAJqv/g66Az5AXclNm wC+3e/aZOl36KeWUQ10WzB0qdCvwE4yfYmaRgiZVZcdQAFWUhGDhjCP//hVEzoGrNBxF pB5jX5U5hF5hbNZbrIsGlZToBS9EkEhTpUxq6OqCzxb0O/0ovUVE+ylmpUEq95awm7j2 M7pg== X-Gm-Message-State: AOJu0Yxrc1XiBumRe3FMm4xPuw5ZJc0jSi8yWDBv9opWxQsJvjC49uwi mtUWD7RoXFsmhrRnbMz/h4IAq7TOiu0YaphTAmHDWvzEGgHhdyB/+ZzlerK0myhlrqI= X-Gm-Gg: AZuq6aJhtpInTFpyUYeGB711QkuIHukhYUq/n6PnkD9aY05C9SbTH/7aXlKEPHzE9FU MfHujHzdXzoJiDHRmVEezjRx5OaeF7X1rs78oAcECnmil4knl4R1cOfPZlMn5kUZCFMfFQrAUC1 eH75SuOnHdSib5/Q3EuNZuTq3CgP99yH5YXDNXtVXxRVsNkORuYLTffQkSRqEHpzAbqfqWXcyZE taq+1vMOzbsYb7ZLawc1zrAl/aA9Y9QQC2gHmTzu+FjMpfiRm32CIn5whfRSyw0c3dXUbnL7bO5 4vLlvv2DQUhu7T2Tm9IrGiHRO/0vgAisajo9uZ2YbFbTAmu4t2VBihdLdCv4qvQqSR2rN3KbDNV xHIEEPDjhfMkHjp7C6GUTN910szKzbLxn6dwPRUZ0usrXvv3lFJdw0k1tbjAcOBdWsC4zhbPbK5 zRmejIX+6drufJukoLRWk= X-Received: by 2002:a05:600c:5307:b0:480:4a4f:c36f with SMTP id 5b1f17b1804b1-4832096671dmr757915e9.21.1770321537557; Thu, 05 Feb 2026 11:58:57 -0800 (PST) From: Ruslan Ruslichenko To: qemu-devel@nongnu.org Cc: qemu-arm@nongnu.org, peter.maydell@linaro.org, artem_mygaiev@epam.com, volodymyr_babchuk@epam.com, takahiro.nakata.wr@renesas.com, "Edgar E . Iglesias" , francisco.iglesias@amd.com, Ruslan_Ruslichenko@epam.com, "Edgar E . Iglesias" Subject: [PATCH 10/29] hw/core: Implement Remote Port packet dispatch logic Date: Thu, 5 Feb 2026 20:58:05 +0100 Message-ID: <20260205195824.2610192-11-ruslichenko.r@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260205195824.2610192-1-ruslichenko.r@gmail.com> References: <20260205195824.2610192-1-ruslichenko.r@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=2a00:1450:4864:20::32d; envelope-from=ruslichenko.r@gmail.com; helo=mail-wm1-x32d.google.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, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZohoMail-DKIM: pass (identity @gmail.com) X-ZM-MESSAGEID: 1770321775670154100 Content-Type: text/plain; charset="utf-8" From: Ruslan Ruslichenko Implement the mechanism to transfer packets from the dedicated protocol thread to the main QEMU execution loop for processing. The patch adds the following features: - signaling logic using internal pipe to wake up the main loop - the rp_process handler, which retrieves packets from queue and dispatches them to the target Remote Port device. This enables QEMU device models to handle remote events. Signed-off-by: Edgar E. Iglesias Signed-off-by: Takahiro Nakata Signed-off-by: Ruslan Ruslichenko --- hw/core/remote-port.c | 148 +++++++++++++++++++++++++++++++++- include/hw/core/remote-port.h | 5 ++ 2 files changed, 152 insertions(+), 1 deletion(-) diff --git a/hw/core/remote-port.c b/hw/core/remote-port.c index 91b0682884..e44d9249c3 100644 --- a/hw/core/remote-port.c +++ b/hw/core/remote-port.c @@ -52,6 +52,8 @@ #define REMOTE_PORT_CLASS(klass) \ OBJECT_CLASS_CHECK(RemotePortClass, (klass), TYPE_REMOTE_PORT) =20 +static void rp_event_read(void *opaque); + static void rp_pkt_dump(const char *prefix, const char *buf, size_t len) { qemu_hexdump(stdout, prefix, buf, len); @@ -96,6 +98,12 @@ ssize_t rp_write(RemotePort *s, const void *buf, size_t = count) return r; } =20 +static unsigned int rp_has_work(RemotePort *s) +{ + unsigned int work =3D s->rx_queue.wpos - s->rx_queue.rpos; + return work; +} + static void rp_cmd_hello(RemotePort *s, struct rp_pkt *pkt) { s->peer.version =3D pkt->hello.version; @@ -187,6 +195,135 @@ static Chardev *rp_autocreate_chardev(RemotePort *s, = char *name) return chr; } =20 +void rp_process(RemotePort *s) +{ + while (true) { + struct rp_pkt *pkt; + unsigned int rpos; + bool actioned =3D false; + RemotePortDevice *dev; + RemotePortDeviceClass *rpdc; + + qemu_mutex_lock(&s->rsp_mutex); + if (!rp_has_work(s)) { + qemu_mutex_unlock(&s->rsp_mutex); + break; + } + rpos =3D s->rx_queue.rpos; + + pkt =3D s->rx_queue.pkt[rpos].pkt; + D(qemu_log("%s: io-thread rpos=3D%d wpos=3D%d cmd=3D%d dev=3D%d\n", + s->prefix, s->rx_queue.rpos, s->rx_queue.wpos, + pkt->hdr.cmd, pkt->hdr.dev)); + + /* + * To handle recursiveness, we need to advance the index + * index before processing the packet. + */ + s->rx_queue.rpos++; + s->rx_queue.rpos %=3D ARRAY_SIZE(s->rx_queue.pkt); + qemu_mutex_unlock(&s->rsp_mutex); + + dev =3D s->devs[pkt->hdr.dev]; + if (dev) { + rpdc =3D REMOTE_PORT_DEVICE_GET_CLASS(dev); + if (rpdc->ops[pkt->hdr.cmd]) { + rpdc->ops[pkt->hdr.cmd](dev, pkt); + actioned =3D true; + } + } + + switch (pkt->hdr.cmd) { + /* TBD */ + default: + assert(actioned); + } + + s->rx_queue.inuse[rpos] =3D false; + qemu_sem_post(&s->rx_queue.sem); + } +} + +static void rp_event_read(void *opaque) +{ + RemotePort *s =3D REMOTE_PORT(opaque); + unsigned char buf[32]; + ssize_t r; + + /* We don't care about the data. Just read it out to clear the event. = */ + do { +#ifdef _WIN32 + r =3D qemu_recv_wrap(s->event.pipe.read, buf, sizeof buf, 0); +#else + r =3D read(s->event.pipe.read, buf, sizeof buf); +#endif + if (r =3D=3D 0) { + return; + } + } while (r =3D=3D sizeof buf || (r < 0 && errno =3D=3D EINTR)); + + rp_process(s); +} + +static void rp_event_notify(RemotePort *s) +{ + unsigned char d =3D 0; + ssize_t r; + +#ifdef _WIN32 + /* Mingw is sensitive about doing write's to socket descriptors. */ + r =3D qemu_send_wrap(s->event.pipe.write, &d, sizeof d, 0); +#else + r =3D qemu_write_full(s->event.pipe.write, &d, sizeof d); +#endif + if (r =3D=3D 0) { + hw_error("%s: pipe closed\n", s->prefix); + } +} + +/* Handover a pkt to CPU or IO-thread context. */ +static void rp_pt_handover_pkt(RemotePort *s, RemotePortDynPkt *dpkt) +{ + bool full; + + /* + * Take the rsp lock around the wpos update, otherwise + * rp_wait_resp will race with us. + */ + qemu_mutex_lock(&s->rsp_mutex); + s->rx_queue.wpos++; + s->rx_queue.wpos %=3D ARRAY_SIZE(s->rx_queue.pkt); + /* + * Ensure rx_queue index update is visible to consumer + * before signaling event, to prevent lost wakeup + */ + smp_mb(); + rp_event_notify(s); + qemu_cond_signal(&s->progress_cond); + qemu_mutex_unlock(&s->rsp_mutex); + + do { + full =3D s->rx_queue.inuse[s->rx_queue.wpos]; + if (full) { + qemu_log("%s: FULL rx queue %d\n", __func__, s->rx_queue.wpos); + if (qemu_sem_timedwait(&s->rx_queue.sem, 2 * 1000) !=3D 0) { +#ifndef _WIN32 + int sval; + +#ifndef CONFIG_SEM_TIMEDWAIT + sval =3D s->rx_queue.sem.count; +#else + sem_getvalue(&s->rx_queue.sem.sem, &sval); +#endif + qemu_log("semwait: %d rpos=3D%u wpos=3D%u\n", sval, + s->rx_queue.rpos, s->rx_queue.wpos); +#endif + qemu_log("Deadlock?\n"); + } + } + } while (full); +} + static bool rp_pt_process_pkt(RemotePort *s, RemotePortDynPkt *dpkt) { struct rp_pkt *pkt =3D dpkt->pkt; @@ -208,7 +345,7 @@ static bool rp_pt_process_pkt(RemotePort *s, RemotePort= DynPkt *dpkt) case RP_CMD_interrupt: case RP_CMD_ats_req: case RP_CMD_ats_inv: - /* TBD */; + rp_pt_handover_pkt(s, dpkt); break; default: g_assert_not_reached(); @@ -312,6 +449,8 @@ static void rp_realize(DeviceState *dev, Error **errp) s->prefix =3D object_get_canonical_path(OBJECT(dev)); =20 qemu_mutex_init(&s->write_mutex); + qemu_mutex_init(&s->rsp_mutex); + qemu_cond_init(&s->progress_cond); =20 if (!qemu_chr_fe_get_driver(&s->chr)) { char *name; @@ -413,6 +552,7 @@ static void rp_realize(DeviceState *dev, Error **errp) s->prefix); exit(EXIT_FAILURE); } + qemu_set_fd_handler(s->event.pipe.read, rp_event_read, NULL, s); } #else if (!g_unix_open_pipe(s->event.pipes, FD_CLOEXEC, NULL)) { @@ -427,7 +567,10 @@ static void rp_realize(DeviceState *dev, Error **errp) exit(EXIT_FAILURE); } =20 + qemu_set_fd_handler(s->event.pipe.read, rp_event_read, NULL, s); #endif + + qemu_sem_init(&s->rx_queue.sem, ARRAY_SIZE(s->rx_queue.pkt) - 1); } =20 static void rp_unrealize(DeviceState *dev) @@ -436,6 +579,9 @@ static void rp_unrealize(DeviceState *dev) =20 s->finalizing =3D true; =20 + /* Unregister handler. */ + qemu_set_fd_handler(s->event.pipe.read, NULL, NULL, s); + info_report("%s: Wait for remote-port to disconnect", s->prefix); qemu_chr_fe_disconnect(&s->chr); qemu_thread_join(&s->thread); diff --git a/include/hw/core/remote-port.h b/include/hw/core/remote-port.h index b88e523894..21dfbe89cd 100644 --- a/include/hw/core/remote-port.h +++ b/include/hw/core/remote-port.h @@ -74,6 +74,9 @@ struct RemotePort { char *chrdev_id; struct rp_peer_state peer; =20 + QemuMutex rsp_mutex; + QemuCond progress_cond; + #define RX_QUEUE_SIZE 1024 struct { /* This array must be sized minimum 2 and always a power of 2. */ @@ -100,6 +103,8 @@ struct RemotePort { RemotePortDevice *devs[REMOTE_PORT_MAX_DEVS]; }; =20 +void rp_process(RemotePort *s); + ssize_t rp_write(RemotePort *s, const void *buf, size_t count); =20 #endif --=20 2.43.0