Re: [PATCH 1/7] Add termios2 support to linux-user

["Daniel P. Berrangé" <berrange@redhat.com>]

On Fri, Oct 31, 2025 at 02:23:21PM +0100, Luca Bonissi wrote:
> From 6ddab7d3ba1035b5e2a6016bde4776436267c18b Mon Sep 17 00:00:00 2001
> From: Luca Bonissi <qemu@bonslack.org>
> Date: Fri, 31 Oct 2025 13:29:19 +0100
> Subject: [PATCH 1/7] Add termios2 support to linux-user

You've added this for a handful of archiecture targets, but
in Fedora we're seeing the incompatibility affect s390x and
aarch64 too, which this series hasn't implemented.

BTW, ideally send a cover letter with a multi-patch
series; there are tools which make this easier than
using git send-email directly:

  https://www.qemu.org/docs/master/devel/submitting-a-patch.html#submitting-your-patches

> 
> Signed-off-by: Luca Bonissi <qemu@bonslack.org>
> ---
>  linux-user/ioctls.h         |  6 +++
>  linux-user/strace.c         | 69 ++++++++++++++++++++++++++++++
>  linux-user/syscall.c        | 84 +++++++++++++++++++++++++++++++++++++
>  linux-user/syscall_types.h  |  3 ++
>  linux-user/user-internals.h |  3 ++
>  5 files changed, 165 insertions(+)
> 
> diff --git a/linux-user/ioctls.h b/linux-user/ioctls.h
> index 2f62fd2cb9..6ecfe6306e 100644
> --- a/linux-user/ioctls.h
> +++ b/linux-user/ioctls.h
> @@ -1,5 +1,11 @@
>       /* emulated ioctl list */
>  
> +#ifdef TARGET_TCGETS2
> +     IOCTL(TCGETS2, IOC_R, MK_PTR(MK_STRUCT(STRUCT_termios2)))
> +     IOCTL(TCSETS2, IOC_W, MK_PTR(MK_STRUCT(STRUCT_termios2)))
> +     IOCTL(TCSETSW2, IOC_W, MK_PTR(MK_STRUCT(STRUCT_termios2)))
> +     IOCTL(TCSETSF2, IOC_W, MK_PTR(MK_STRUCT(STRUCT_termios2)))
> +#endif
>       IOCTL(TCGETS, IOC_R, MK_PTR(MK_STRUCT(STRUCT_termios)))
>       IOCTL(TCSETS, IOC_W, MK_PTR(MK_STRUCT(STRUCT_termios)))
>       IOCTL(TCSETSF, IOC_W, MK_PTR(MK_STRUCT(STRUCT_termios)))
> diff --git a/linux-user/strace.c b/linux-user/strace.c
> index 758c5d32b6..7afb94544f 100644
> --- a/linux-user/strace.c
> +++ b/linux-user/strace.c
> @@ -1935,6 +1935,75 @@ print_termios(void *arg)
>      qemu_log("}");
>  }
>  
> +#ifdef TARGET_TCGETS2
> +void
> +print_termios2(void *arg)
> +{
> +    const struct target_termios2 *target = arg;
> +
> +    target_tcflag_t iflags = tswap32(target->c_iflag);
> +    target_tcflag_t oflags = tswap32(target->c_oflag);
> +    target_tcflag_t cflags = tswap32(target->c_cflag);
> +    target_tcflag_t lflags = tswap32(target->c_lflag);
> +
> +    qemu_log("{");
> +
> +    qemu_log("c_iflag = ");
> +    print_flags(termios_iflags, iflags, 0);
> +
> +    qemu_log("c_oflag = ");
> +    target_tcflag_t oflags_clean =  oflags & ~(TARGET_NLDLY | TARGET_CRDLY |
> +                                               TARGET_TABDLY | TARGET_BSDLY |
> +                                               TARGET_VTDLY | TARGET_FFDLY);
> +    print_flags(termios_oflags, oflags_clean, 0);
> +    if (oflags & TARGET_NLDLY) {
> +        print_enums(termios_oflags_NLDLY, oflags & TARGET_NLDLY, 0);
> +    }
> +    if (oflags & TARGET_CRDLY) {
> +        print_enums(termios_oflags_CRDLY, oflags & TARGET_CRDLY, 0);
> +    }
> +    if (oflags & TARGET_TABDLY) {
> +        print_enums(termios_oflags_TABDLY, oflags & TARGET_TABDLY, 0);
> +    }
> +    if (oflags & TARGET_BSDLY) {
> +        print_enums(termios_oflags_BSDLY, oflags & TARGET_BSDLY, 0);
> +    }
> +    if (oflags & TARGET_VTDLY) {
> +        print_enums(termios_oflags_VTDLY, oflags & TARGET_VTDLY, 0);
> +    }
> +    if (oflags & TARGET_FFDLY) {
> +        print_enums(termios_oflags_FFDLY, oflags & TARGET_FFDLY, 0);
> +    }
> +
> +    qemu_log("c_cflag = ");
> +    if (cflags & TARGET_CBAUD) {
> +        print_enums(termios_cflags_CBAUD, cflags & TARGET_CBAUD, 0);
> +    }
> +    if (cflags & TARGET_CSIZE) {
> +        print_enums(termios_cflags_CSIZE, cflags & TARGET_CSIZE, 0);
> +    }
> +    target_tcflag_t cflags_clean = cflags & ~(TARGET_CBAUD | TARGET_CSIZE);
> +    print_flags(termios_cflags, cflags_clean, 0);
> +
> +    qemu_log("c_lflag = ");
> +    print_flags(termios_lflags, lflags, 0);
> +
> +    qemu_log("c_ispeed = ");
> +    print_raw_param("%u", tswap32(target->c_ispeed), 0);
> +
> +    qemu_log("c_ospeed = ");
> +    print_raw_param("%u", tswap32(target->c_ospeed), 0);
> +
> +    qemu_log("c_cc = ");
> +    qemu_log("\"%s\",", target->c_cc);
> +
> +    qemu_log("c_line = ");
> +    print_raw_param("\'%c\'", target->c_line, 1);
> +
> +    qemu_log("}");
> +}
> +#endif
> +
>  #undef UNUSED
>  
>  #ifdef TARGET_NR_accept
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index 8546f48a05..920bf23406 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -86,6 +86,7 @@
>  #endif
>  
>  #define termios host_termios
> +#define termios2 host_termios2
>  #define winsize host_winsize
>  #define termio host_termio
>  #define sgttyb host_sgttyb /* same as target */
> @@ -5885,6 +5886,89 @@ static const StructEntry struct_termios_def = {
>      .print = print_termios,
>  };
>  
> +#ifdef TARGET_TCGETS2
> +static void target_to_host_termios2 (void *dst, const void *src)
> +{
> +    struct host_termios2 *host = dst;
> +    const struct target_termios2 *target = src;
> +
> +    host->c_iflag =
> +        target_to_host_bitmask(tswap32(target->c_iflag), iflag_tbl);
> +    host->c_oflag =
> +        target_to_host_bitmask(tswap32(target->c_oflag), oflag_tbl);
> +    host->c_cflag =
> +        target_to_host_bitmask(tswap32(target->c_cflag), cflag_tbl);
> +    host->c_lflag =
> +        target_to_host_bitmask(tswap32(target->c_lflag), lflag_tbl);
> +    host->c_line = target->c_line;
> +    host->c_ispeed = tswap32(target->c_ispeed);
> +    host->c_ospeed = tswap32(target->c_ospeed);
> +
> +    memset(host->c_cc, 0, sizeof(host->c_cc));
> +    host->c_cc[VINTR] = target->c_cc[TARGET_VINTR];
> +    host->c_cc[VQUIT] = target->c_cc[TARGET_VQUIT];
> +    host->c_cc[VERASE] = target->c_cc[TARGET_VERASE];
> +    host->c_cc[VKILL] = target->c_cc[TARGET_VKILL];
> +    host->c_cc[VEOF] = target->c_cc[TARGET_VEOF];
> +    host->c_cc[VTIME] = target->c_cc[TARGET_VTIME];
> +    host->c_cc[VMIN] = target->c_cc[TARGET_VMIN];
> +    host->c_cc[VSWTC] = target->c_cc[TARGET_VSWTC];
> +    host->c_cc[VSTART] = target->c_cc[TARGET_VSTART];
> +    host->c_cc[VSTOP] = target->c_cc[TARGET_VSTOP];
> +    host->c_cc[VSUSP] = target->c_cc[TARGET_VSUSP];
> +    host->c_cc[VEOL] = target->c_cc[TARGET_VEOL];
> +    host->c_cc[VREPRINT] = target->c_cc[TARGET_VREPRINT];
> +    host->c_cc[VDISCARD] = target->c_cc[TARGET_VDISCARD];
> +    host->c_cc[VWERASE] = target->c_cc[TARGET_VWERASE];
> +    host->c_cc[VLNEXT] = target->c_cc[TARGET_VLNEXT];
> +    host->c_cc[VEOL2] = target->c_cc[TARGET_VEOL2];
> +}
> +
> +static void host_to_target_termios2 (void *dst, const void *src)
> +{
> +    struct target_termios2 *target = dst;
> +    const struct host_termios2 *host = src;
> +
> +    target->c_iflag =
> +        tswap32(host_to_target_bitmask(host->c_iflag, iflag_tbl));
> +    target->c_oflag =
> +        tswap32(host_to_target_bitmask(host->c_oflag, oflag_tbl));
> +    target->c_cflag =
> +        tswap32(host_to_target_bitmask(host->c_cflag, cflag_tbl));
> +    target->c_lflag =
> +        tswap32(host_to_target_bitmask(host->c_lflag, lflag_tbl));
> +    target->c_line = host->c_line;
> +    target->c_ispeed = tswap32(host->c_ispeed);
> +    target->c_ospeed = tswap32(host->c_ospeed);
> +
> +    memset(target->c_cc, 0, sizeof(target->c_cc));
> +    target->c_cc[TARGET_VINTR] = host->c_cc[VINTR];
> +    target->c_cc[TARGET_VQUIT] = host->c_cc[VQUIT];
> +    target->c_cc[TARGET_VERASE] = host->c_cc[VERASE];
> +    target->c_cc[TARGET_VKILL] = host->c_cc[VKILL];
> +    target->c_cc[TARGET_VEOF] = host->c_cc[VEOF];
> +    target->c_cc[TARGET_VTIME] = host->c_cc[VTIME];
> +    target->c_cc[TARGET_VMIN] = host->c_cc[VMIN];
> +    target->c_cc[TARGET_VSWTC] = host->c_cc[VSWTC];
> +    target->c_cc[TARGET_VSTART] = host->c_cc[VSTART];
> +    target->c_cc[TARGET_VSTOP] = host->c_cc[VSTOP];
> +    target->c_cc[TARGET_VSUSP] = host->c_cc[VSUSP];
> +    target->c_cc[TARGET_VEOL] = host->c_cc[VEOL];
> +    target->c_cc[TARGET_VREPRINT] = host->c_cc[VREPRINT];
> +    target->c_cc[TARGET_VDISCARD] = host->c_cc[VDISCARD];
> +    target->c_cc[TARGET_VWERASE] = host->c_cc[VWERASE];
> +    target->c_cc[TARGET_VLNEXT] = host->c_cc[VLNEXT];
> +    target->c_cc[TARGET_VEOL2] = host->c_cc[VEOL2];
> +}
> +
> +static const StructEntry struct_termios2_def = {
> +    .convert = { host_to_target_termios2, target_to_host_termios2 },
> +    .size = { sizeof(struct target_termios2), sizeof(struct host_termios2) },
> +    .align = { __alignof__(struct target_termios2), __alignof__(struct host_termios2) },
> +    .print = print_termios2,
> +};
> +#endif
> +
>  /* If the host does not provide these bits, they may be safely discarded. */
>  #ifndef MAP_SYNC
>  #define MAP_SYNC 0
> diff --git a/linux-user/syscall_types.h b/linux-user/syscall_types.h
> index 6dd7a80ce5..ac45705acf 100644
> --- a/linux-user/syscall_types.h
> +++ b/linux-user/syscall_types.h
> @@ -1,4 +1,7 @@
>  STRUCT_SPECIAL(termios)
> +#ifdef TARGET_TCGETS2
> +STRUCT_SPECIAL(termios2)
> +#endif
>  
>  STRUCT(winsize,
>         TYPE_SHORT, TYPE_SHORT, TYPE_SHORT, TYPE_SHORT)
> diff --git a/linux-user/user-internals.h b/linux-user/user-internals.h
> index 7099349ec8..067c02bb93 100644
> --- a/linux-user/user-internals.h
> +++ b/linux-user/user-internals.h
> @@ -129,6 +129,9 @@ static inline uint64_t target_offset64(uint64_t word0, uint64_t word1)
>  #endif /* TARGET_ABI_BITS != 32 */
>  
>  void print_termios(void *arg);
> +#ifdef TARGET_TCGETS2
> +void print_termios2(void *arg);
> +#endif
>  
>  /* ARM EABI and MIPS expect 64bit types aligned even on pairs or registers */
>  #ifdef TARGET_ARM
> -- 
> 2.50.1
> 
> 
> 

With regards,
Daniel
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