From: Thiago Jung Bauermann <thiago.bauermann@linaro.org>
To: Luis Machado <luis.machado@arm.com>
Cc: gdb-patches@sourceware.org
Subject: Re: [PATCH v3 07/16] [gdbserver/aarch64] sme: Add support for SME
Date: Thu, 27 Jul 2023 16:41:09 -0300 [thread overview]
Message-ID: <87edkt87my.fsf@linaro.org> (raw)
In-Reply-To: <20230630134616.1238105-8-luis.machado@arm.com>
Hello,
No real comment on this one, looks good to me.
Luis Machado via Gdb-patches <gdb-patches@sourceware.org> writes:
> Enable SME support in gdbserver by adjusting the usual fields. There is
> not much to this patch because the code is either in gdb or it is shared
> between gdbserver and gdb. One exception is the bump to gdbserver's
> PBUFSIZ from 18432 to 131104.
>
> Since the ZA register can be quite big (256 * 256 bytes), the g/G remote
> packet will also become quite big
>
> From gdbserver/tdesc.cc:init_target_desc, I estimated the new size should
> be at least (2 * 256 * 256 + 32), which yields 131104.
>
> It is also unlikely we will find a process starting up with SVL set to 256.
>
> Ideally we'd adjust the packet size dynamically based on what we need, but
> for now this should do.
>
> Please note we have the same limitation for SME that we have for SVE, and
> that is the fact gdbserver cannot communicate vector length changes to gdb
> via the remote protocol.
>
> Thiago is working on this improvement, which hopefully will be able to be
> adapted to SME in an easy way.
Unfortunately this was paused due to other Linaro work, but I'm resuming
it now.
> Co-Authored-By: Ezra Sitorus <ezra.sitorus@arm.com>
> ---
> gdbserver/linux-aarch64-low.cc | 74 ++++++++++++++++++++++++++++++++
> gdbserver/linux-aarch64-tdesc.cc | 7 +++
> gdbserver/server.h | 2 +-
> 3 files changed, 82 insertions(+), 1 deletion(-)
>
> diff --git a/gdbserver/linux-aarch64-low.cc b/gdbserver/linux-aarch64-low.cc
> index 7c633c212f3..95688480c3d 100644
> --- a/gdbserver/linux-aarch64-low.cc
> +++ b/gdbserver/linux-aarch64-low.cc
> @@ -41,6 +41,7 @@
> #include "gdb_proc_service.h"
> #include "arch/aarch64.h"
> #include "arch/aarch64-mte-linux.h"
> +#include "arch/aarch64-scalable-linux.h"
> #include "linux-aarch32-tdesc.h"
> #include "linux-aarch64-tdesc.h"
> #include "nat/aarch64-mte-linux-ptrace.h"
> @@ -750,6 +751,66 @@ aarch64_sve_regs_copy_from_regcache (struct regcache *regcache, void *buf)
> memcpy (buf, sve_state.data (), sve_state.size ());
> }
>
> +/* Wrapper for aarch64_za_regs_copy_to_reg_buf, to help copying NT_ARM_ZA
> + state from the thread (BUF) to the register cache. */
> +
> +static void
> +aarch64_za_regs_copy_to_regcache (struct regcache *regcache,
> + ATTRIBUTE_UNUSED const void *buf)
> +{
> + /* BUF is unused here since we collect the data straight from a ptrace
> + request, therefore bypassing gdbserver's own call to ptrace. */
It's a bit of a pity that that the result of that ptrace call goes
unused. If ZA's regset_info.size was set to
sizeof (struct user_za_header) then it could be used to fetch the header
that aarch64_fetch_za_regset () needs.
But I imagine that there's no need for performance in this code path so
it's just a theoretical concern. Also, SVE already works this way.
--
Thiago
next prev parent reply other threads:[~2023-07-27 19:41 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-30 13:46 [PATCH v3 00/16] SME support for AArch64 gdb/gdbserver on Linux Luis Machado
2023-06-30 13:46 ` [PATCH v3 01/16] [gdb/aarch64] Fix register fetch/store order for native AArch64 Linux Luis Machado
2023-07-24 15:53 ` Thiago Jung Bauermann
2023-07-24 16:26 ` Luis Machado
2023-06-30 13:46 ` [PATCH v3 02/16] [gdb/aarch64] refactor: Rename SVE-specific files Luis Machado
2023-06-30 13:46 ` [PATCH v3 03/16] [gdb/gdbserver] refactor: Simplify SVE interface to read/write registers Luis Machado
2023-07-24 16:19 ` Thiago Jung Bauermann
2023-07-25 9:28 ` Luis Machado
2023-06-30 13:46 ` [PATCH v3 04/16] [gdb/aarch64] sve: Fix return command when using V registers in a SVE-enabled target Luis Machado
2023-06-30 13:46 ` [PATCH v3 05/16] [gdb/aarch64] sme: Enable SME registers and pseudo-registers Luis Machado
2023-07-26 20:01 ` Thiago Jung Bauermann
2023-07-27 9:01 ` Luis Machado
2023-07-28 1:19 ` Thiago Jung Bauermann
2023-06-30 13:46 ` [PATCH v3 06/16] [gdbserver/aarch64] refactor: Adjust expedited registers dynamically Luis Machado
2023-06-30 13:46 ` [PATCH v3 07/16] [gdbserver/aarch64] sme: Add support for SME Luis Machado
2023-07-27 19:41 ` Thiago Jung Bauermann [this message]
2023-06-30 13:46 ` [PATCH v3 08/16] [gdb/aarch64] sve: Fix signal frame z/v register restore Luis Machado
2023-07-27 21:52 ` Thiago Jung Bauermann
2023-07-31 12:22 ` Luis Machado
2023-06-30 13:46 ` [PATCH v3 09/16] [gdb/aarch64] sme: Signal frame support Luis Machado
2023-07-27 22:25 ` Thiago Jung Bauermann
2023-07-31 12:23 ` Luis Machado
2023-06-30 13:46 ` [PATCH v3 10/16] [gdb/aarch64] sme: Fixup sigframe gdbarch when vg/svg changes Luis Machado
2023-07-28 1:01 ` Thiago Jung Bauermann
2023-07-31 12:27 ` Luis Machado
2023-06-30 13:46 ` [PATCH v3 11/16] [gdb/aarch64] sme: Support TPIDR2 signal frame context Luis Machado
2023-06-30 13:46 ` [PATCH v3 12/16] [gdb/generic] corefile/bug: Use thread-specific gdbarch when dumping register state to core files Luis Machado
2023-06-30 13:46 ` [PATCH v3 13/16] [gdb/generic] corefile/bug: Fixup (gcore) core file target description reading order Luis Machado
2023-07-28 3:12 ` Thiago Jung Bauermann
2023-07-31 11:38 ` Luis Machado
2023-09-05 8:28 ` Luis Machado
2023-06-30 13:46 ` [PATCH v3 14/16] [gdb/aarch64] sme: Core file support for Linux Luis Machado
2023-08-03 0:18 ` Thiago Jung Bauermann
2023-08-03 11:37 ` Luis Machado
2023-08-04 20:45 ` Thiago Jung Bauermann
2023-06-30 13:46 ` [PATCH v3 15/16] [gdb/testsuite] sme: Add SVE/SME testcases Luis Machado
2023-08-04 0:59 ` Thiago Jung Bauermann
2023-08-11 15:42 ` Luis Machado
2023-08-12 0:42 ` Thiago Jung Bauermann
2023-06-30 13:46 ` [PATCH v3 16/16] [gdb/docs] sme: Document SME registers and features Luis Machado
2023-07-01 8:58 ` Eli Zaretskii
2023-07-03 9:52 ` Luis Machado
2023-07-03 12:03 ` Eli Zaretskii
2023-07-03 12:06 ` Luis Machado
2023-07-17 11:40 ` [PING][PATCH v3 00/16] SME support for AArch64 gdb/gdbserver on Linux Luis Machado
2023-07-24 8:15 ` Luis Machado
2023-08-04 21:24 ` [PATCH " Thiago Jung Bauermann
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=87edkt87my.fsf@linaro.org \
--to=thiago.bauermann@linaro.org \
--cc=gdb-patches@sourceware.org \
--cc=luis.machado@arm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).