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* [PATCH] hw/riscv/virt.c: re-insert and deprecate 'riscv,delegate'
@ 2024-07-13 17:43 Daniel Henrique Barboza
  2024-07-13 18:57 ` [PATCH] hw/riscv/virt.c: re-insert and deprecate 'riscv, delegate' Conor Dooley
                   ` (2 more replies)
  0 siblings, 3 replies; 5+ messages in thread
From: Daniel Henrique Barboza @ 2024-07-13 17:43 UTC (permalink / raw)
  To: qemu-devel
  Cc: qemu-riscv, alistair.francis, bmeng, liwei1518, zhiwei_liu,
	palmer, Daniel Henrique Barboza, Conor Dooley, Anup Patel

Commit b1f1e9dcfa renamed 'riscv,delegate' to 'riscv,delegation' since
it is the correct name as per dt-bindings, and the absence of the
correct name will result in validation fails when dumping the dtb and
using dt-validate.

But this change has a side-effect: every other firmware available that
is AIA capable is using 'riscv,delegate', and it will fault/misbehave if
this property isn't present. The property was added back in QEMU 7.0,
meaning we have 2 years of firmware development using the wrong
property.

Re-introducing 'riscv,delegate' while keeping 'riscv,delegation' will
make current firmwares to keep booting with the 'virt' machine and
dt-validate won't complain about it since we're still using the expected
property 'riscv,delegation'. 'riscv,delegate' is then marked for future
deprecation and its use is being discouraged.

Cc: Conor Dooley <conor@kernel.org>
Cc: Anup Patel <apatel@ventanamicro.com>
Fixes: b1f1e9dcfa ("hw/riscv/virt.c: aplic DT: rename prop to 'riscv, delegation'")
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 docs/about/deprecated.rst | 11 +++++++++++
 hw/riscv/virt.c           |  9 +++++++++
 2 files changed, 20 insertions(+)

diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst
index 20b7a17cf0..88f0f03786 100644
--- a/docs/about/deprecated.rst
+++ b/docs/about/deprecated.rst
@@ -479,6 +479,17 @@ versions, aliases will point to newer CPU model versions
 depending on the machine type, so management software must
 resolve CPU model aliases before starting a virtual machine.
 
+RISC-V "virt" board "riscv,delegate" DT property (since 9.1)
+''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
+
+The "riscv,delegate" DT property was added in QEMU 7.0 as part of
+the AIA APLIC support.  The property changed name during the review
+process in Linux and the correct name ended up being
+"riscv,delegation".  Changing the DT property name will break all
+available firmwares that are using the current (wrong) name.  The
+property is kept as is in 9.1, together with "riscv,delegation", to
+give more time for firmware developers to change their code.
+
 Migration
 ---------
 
diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c
index bc0893e087..9981e0f6c9 100644
--- a/hw/riscv/virt.c
+++ b/hw/riscv/virt.c
@@ -651,6 +651,15 @@ static void create_fdt_one_aplic(RISCVVirtState *s, int socket,
         qemu_fdt_setprop_cells(ms->fdt, aplic_name, "riscv,delegation",
                                aplic_child_phandle, 0x1,
                                VIRT_IRQCHIP_NUM_SOURCES);
+        /*
+         * DEPRECATED_9.1: Compat property kept temporarily
+         * to allow old firmwares to work with AIA. Do *not*
+         * use 'riscv,delegate' in new code: use
+         * 'riscv,delegation' instead.
+         */
+        qemu_fdt_setprop_cells(ms->fdt, aplic_name, "riscv,delegate",
+                               aplic_child_phandle, 0x1,
+                               VIRT_IRQCHIP_NUM_SOURCES);
     }
 
     riscv_socket_fdt_write_id(ms, aplic_name, socket);
-- 
2.45.2



^ permalink raw reply related	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2024-07-15  8:54 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
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2024-07-13 17:43 [PATCH] hw/riscv/virt.c: re-insert and deprecate 'riscv,delegate' Daniel Henrique Barboza
2024-07-13 18:57 ` [PATCH] hw/riscv/virt.c: re-insert and deprecate 'riscv, delegate' Conor Dooley
2024-07-15  8:54   ` Daniel Henrique Barboza
2024-07-14 23:02 ` Alistair Francis
2024-07-15  0:35 ` Alistair Francis

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