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[2403:580b:97e8:0:82ce:f179:8a79:69f4]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-718e58c68d3sm2528155b3a.84.2024.09.08.19.13.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 08 Sep 2024 19:13:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1725848012; x=1726452812; 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=KsWFRdYWdBaST8wvMPQrZTKJI/aAOCM7Gcb6EQnnHW0=; b=fp/I4hxbwHYB0yref/vM8j8PFDTwuTCDxD084PL5zqsjwyUkQor2kXxTL6oyOpJSd5 fkVA58CIHzi2v4XYTA1hPQ1i/Y+yHwDV8QGrqXxfz2Xn326Byns8W/mWEo/u9exV7pWd /RxEQybHKlxQA+XpridAJKVvZqDYAq8IfofMX+BQV2JrQLxvWUpZyLt0MnK9ydy7EhB0 i0EgAK13dEX0NZodfMbLDdH7H2lvfrS+UvfrnFSgcSTmyGg2xkErU6DQvODws+G6OSZ8 bTWo90qyy1dd0UWGwAGCxlxHutfOXz+5BO8rrOiCO+CH8aXMaBV5IXEsOUbku6Tl7mCO UYSg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1725848012; x=1726452812; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=KsWFRdYWdBaST8wvMPQrZTKJI/aAOCM7Gcb6EQnnHW0=; b=Pog8wuujTLIbOk6GLwx8/ADdrboSVyZIhaYmAaPW2kMclbKI+G4BuBgaBSttGGjBNr TdbdV6rUN8GPSjLHL1+9H2+BLjjPX6UcY6pL+EUDw1mnMiQLxYP1JYPVoFRpaxNkk21T Lg+AG6N6scZB629VlncLGWrNi1NRzVyMz5ifssTXDV4ZOZ9o6qub2vUG07m6985GBSyG KOAkML8eh6dv8EfzCMA6bi+i0gK5klWY+Z75i5C8qVcX2TptXdTijtFFcKuyvgJpKDuY JD64SW5eCT+9w+syATtbQbgIgMAVj3NbvK6Iw8aiBJ05VCnedwhNYKdNDcgH028Bye83 YDcQ== X-Forwarded-Encrypted: i=1; AJvYcCVcZ94SYwLvSG2v0lpXJDfTfQcrGmovooQ1ggRVv2+31nXUnrdh2ODucnbAATSPpqQk+kv956teJ3hs@nongnu.org, AJvYcCWeM/K4YfUL0PhRs4lo/umA7+M5S0WUEyKWLrwmo+KYXRVF8yJNMqbN+KLOxmXG3OG/ahu6KBLSfwjgVA==@nongnu.org X-Gm-Message-State: AOJu0YxxshQ5NlPMoL1wKstJXhDdRc/NufxKFdIybz/jt/tjh9hf2H1W VtDguTwQiL6AQ9UCUrRw5+pnlHSCUBk0uV9t/dLPjIzd6PRlKRF8 X-Google-Smtp-Source: AGHT+IH9xuG0htxZ1C7TbpVaozzZ/Alh/YT/2G4WBIFBzExcL5hmH0GOeqZfjTKEsoj2iKTGO15V+g== X-Received: by 2002:a05:6a20:271d:b0:1cf:2d2f:34fa with SMTP id adf61e73a8af0-1cf2d2f365emr7292964637.25.1725848012201; Sun, 08 Sep 2024 19:13:32 -0700 (PDT) From: Alistair Francis X-Google-Original-From: Alistair Francis To: alex.bennee@linaro.org, qemu-devel@nongnu.org, peter.maydell@linaro.org Cc: dbarboza@ventanamicro.com, palmer@dabbelt.com, zhiwei_liu@linux.alibaba.com, qemu-riscv@nongnu.org, Paolo Bonzini , alistair23@gmail.com, Bin Meng , liwei1518@gmail.com, Alistair Francis , =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= , atishp@rivosinc.com, Alistair Francis , Thomas Huth Subject: [PATCH v3 1/2] hw/char: riscv_htif: Use blocking qemu_chr_fe_write_all Date: Mon, 9 Sep 2024 12:13:16 +1000 Message-ID: <20240909021317.58192-2-alistair.francis@wdc.com> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20240909021317.58192-1-alistair.francis@wdc.com> References: <20240909021317.58192-1-alistair.francis@wdc.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=2607:f8b0:4864:20::433; envelope-from=alistair23@gmail.com; helo=mail-pf1-x433.google.com X-Spam_score_int: -17 X-Spam_score: -1.8 X-Spam_bar: - X-Spam_report: (-1.8 / 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_ENVFROM_END_DIGIT=0.25, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, 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+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZohoMail-DKIM: pass (identity @gmail.com) X-ZM-MESSAGEID: 1725848068178116600 Content-Type: text/plain; charset="utf-8" The current approach of using qemu_chr_fe_write() and ignoring the return values results in dropped characters [1]. Ideally we want to report FIFO status to the guest, but the HTIF isn't a real UART, so we don't really have a way to do that. Instead let's just use qemu_chr_fe_write_all() so at least we don't drop characters. 1: https://gitlab.com/qemu-project/qemu/-/issues/2114 Signed-off-by: Alistair Francis Reviewed-by: Daniel Henrique Barboza Reviewed-by: Thomas Huth --- hw/char/riscv_htif.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/hw/char/riscv_htif.c b/hw/char/riscv_htif.c index 9bef60def1..d40b542948 100644 --- a/hw/char/riscv_htif.c +++ b/hw/char/riscv_htif.c @@ -218,7 +218,11 @@ static void htif_handle_tohost_write(HTIFState *s, uin= t64_t val_written) tswap64(syscall[3]) =3D=3D HTIF_CONSOLE_CMD_PUTC) { uint8_t ch; cpu_physical_memory_read(tswap64(syscall[2]), &ch, 1); - qemu_chr_fe_write(&s->chr, &ch, 1); + /* + * XXX this blocks entire thread. Rewrite to use + * qemu_chr_fe_write and background I/O callbacks + */ + qemu_chr_fe_write_all(&s->chr, &ch, 1); resp =3D 0x100 | (uint8_t)payload; } else { qemu_log_mask(LOG_UNIMP, @@ -237,7 +241,11 @@ static void htif_handle_tohost_write(HTIFState *s, uin= t64_t val_written) return; } else if (cmd =3D=3D HTIF_CONSOLE_CMD_PUTC) { uint8_t ch =3D (uint8_t)payload; - qemu_chr_fe_write(&s->chr, &ch, 1); + /* + * XXX this blocks entire thread. Rewrite to use + * qemu_chr_fe_write and background I/O callbacks + */ + qemu_chr_fe_write_all(&s->chr, &ch, 1); resp =3D 0x100 | (uint8_t)payload; } else { qemu_log("HTIF device %d: unknown command\n", device); --=20 2.46.0