diff options
| author | Alistair Francis <alistair.francis@wdc.com> | 2024-08-13 13:32:51 +1000 |
|---|---|---|
| committer | Alistair Francis <alistair.francis@wdc.com> | 2024-10-30 11:22:08 +1000 |
| commit | 4a0e8ca322d2a5ec9bdd9409cb02d4c08a07bef6 (patch) | |
| tree | 37387803a8d665aaafbb8ec43f8d42b310d29083 /hw/char/riscv_htif.c | |
| parent | 2ae6cca1d3389801ee72fc5e58c52573218f3514 (diff) | |
hw/char: riscv_htif: Use blocking qemu_chr_fe_write_all
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 <alistair.francis@wdc.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20240910045419.1252277-2-alistair.francis@wdc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Diffstat (limited to 'hw/char/riscv_htif.c')
| -rw-r--r-- | hw/char/riscv_htif.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/hw/char/riscv_htif.c b/hw/char/riscv_htif.c index 54fd55c3e6..0345088e8b 100644 --- a/hw/char/riscv_htif.c +++ b/hw/char/riscv_htif.c @@ -217,7 +217,11 @@ static void htif_handle_tohost_write(HTIFState *s, uint64_t val_written) tswap64(syscall[3]) == 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 = 0x100 | (uint8_t)payload; } else { qemu_log_mask(LOG_UNIMP, @@ -236,7 +240,11 @@ static void htif_handle_tohost_write(HTIFState *s, uint64_t val_written) return; } else if (cmd == HTIF_CONSOLE_CMD_PUTC) { uint8_t ch = (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 = 0x100 | (uint8_t)payload; } else { qemu_log("HTIF device %d: unknown command\n", device); |