1. Patchew
  2. QEMU
  3. View series

[PATCH v2] hw/acpi: correct field sequence in SPCR table

Heinrich Schuchardt posted 1 patch 1 week ago
Patches applied successfully (tree, apply log)
git fetch https://github.com/patchew-project/qemu tags/patchew/20260326144835.67911-1-heinrich.schuchardt@canonical.com
Maintainers: "Michael S. Tsirkin" <mst@redhat.com>, Igor Mammedov <imammedo@redhat.com>, Ani Sinha <anisinha@redhat.com>
hw/acpi/aml-build.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
[PATCH v2] hw/acpi: correct field sequence in SPCR table
Posted by Heinrich Schuchardt 1 week ago 
On LoongArch and RISC-V invalid SPCR tables are created:

Terrminal Type : 00
Language : 03

The correct values are:

Terrminal Type : 03
Language : 00

This is due to commit 7dd0b070fa09 ("hw/arm/virt-acpi-build.c: Migrate
SPCR creation to common location") that swapped the fields.

See the specification of the table in
https://learn.microsoft.com/en-us/windows-hardware/drivers/bringup/serial-port-console-redirection-table

This page shows version 1.10. But the sequence of the fields was not changed
since version 1.0.

Our LoongArch and ARM code uses version 1.07 of the specification.
Our RISC-V code uses version 1.10 of the specification.

Fixes: 7dd0b070fa09 ("hw/arm/virt-acpi-build.c: Migrate SPCR creation to common location")
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Origin: https://lore.kernel.org/qemu-devel/20260326121947.51200-1-heinrich.schuchardt@canonical.com/T/#u
Bug-Ubuntu: https://bugs.launchpad.net/ubuntu/+source/qemu/+bug/2146419
---
v2:
	Mention the different specification versions used by our code.
v1:
	https://lore.kernel.org/qemu-devel/20260326121947.51200-1-heinrich.schuchardt@canonical.com/T/#u
---
 hw/acpi/aml-build.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c
index 4b37405088..a999320e61 100644
--- a/hw/acpi/aml-build.c
+++ b/hw/acpi/aml-build.c
@@ -2115,10 +2115,10 @@ void build_spcr(GArray *table_data, BIOSLinker *linker,
     build_append_int_noprefix(table_data, f->stop_bits, 1);
     /* Flow Control */
     build_append_int_noprefix(table_data, f->flow_control, 1);
-    /* Language */
-    build_append_int_noprefix(table_data, f->language, 1);
     /* Terminal Type */
     build_append_int_noprefix(table_data, f->terminal_type, 1);
+    /* Language */
+    build_append_int_noprefix(table_data, f->language, 1);
     /* PCI Device ID  */
     build_append_int_noprefix(table_data, f->pci_device_id, 2);
     /* PCI Vendor ID */
-- 
2.53.0
Re: [PATCH v2] hw/acpi: correct field sequence in SPCR table
Posted by Alistair Francis 1 day, 14 hours ago 
On Fri, Mar 27, 2026 at 12:49 AM Heinrich Schuchardt
<heinrich.schuchardt@canonical.com> wrote:
>
> On LoongArch and RISC-V invalid SPCR tables are created:
>
> Terrminal Type : 00
> Language : 03
>
> The correct values are:
>
> Terrminal Type : 03
> Language : 00
>
> This is due to commit 7dd0b070fa09 ("hw/arm/virt-acpi-build.c: Migrate
> SPCR creation to common location") that swapped the fields.
>
> See the specification of the table in
> https://learn.microsoft.com/en-us/windows-hardware/drivers/bringup/serial-port-console-redirection-table
>
> This page shows version 1.10. But the sequence of the fields was not changed
> since version 1.0.
>
> Our LoongArch and ARM code uses version 1.07 of the specification.
> Our RISC-V code uses version 1.10 of the specification.
>
> Fixes: 7dd0b070fa09 ("hw/arm/virt-acpi-build.c: Migrate SPCR creation to common location")
> Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
> Origin: https://lore.kernel.org/qemu-devel/20260326121947.51200-1-heinrich.schuchardt@canonical.com/T/#u
> Bug-Ubuntu: https://bugs.launchpad.net/ubuntu/+source/qemu/+bug/2146419

Thanks!

Applied to riscv-to-apply.next

Alistair

> ---
> v2:
>         Mention the different specification versions used by our code.
> v1:
>         https://lore.kernel.org/qemu-devel/20260326121947.51200-1-heinrich.schuchardt@canonical.com/T/#u
> ---
>  hw/acpi/aml-build.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c
> index 4b37405088..a999320e61 100644
> --- a/hw/acpi/aml-build.c
> +++ b/hw/acpi/aml-build.c
> @@ -2115,10 +2115,10 @@ void build_spcr(GArray *table_data, BIOSLinker *linker,
>      build_append_int_noprefix(table_data, f->stop_bits, 1);
>      /* Flow Control */
>      build_append_int_noprefix(table_data, f->flow_control, 1);
> -    /* Language */
> -    build_append_int_noprefix(table_data, f->language, 1);
>      /* Terminal Type */
>      build_append_int_noprefix(table_data, f->terminal_type, 1);
> +    /* Language */
> +    build_append_int_noprefix(table_data, f->language, 1);
>      /* PCI Device ID  */
>      build_append_int_noprefix(table_data, f->pci_device_id, 2);
>      /* PCI Vendor ID */
> --
> 2.53.0
>
>
Re: [PATCH v2] hw/acpi: correct field sequence in SPCR table
Posted by Alistair Francis 1 day, 15 hours ago 
On Fri, Mar 27, 2026 at 12:49 AM Heinrich Schuchardt
<heinrich.schuchardt@canonical.com> wrote:
>
> On LoongArch and RISC-V invalid SPCR tables are created:
>
> Terrminal Type : 00
> Language : 03
>
> The correct values are:
>
> Terrminal Type : 03
> Language : 00
>
> This is due to commit 7dd0b070fa09 ("hw/arm/virt-acpi-build.c: Migrate
> SPCR creation to common location") that swapped the fields.
>
> See the specification of the table in
> https://learn.microsoft.com/en-us/windows-hardware/drivers/bringup/serial-port-console-redirection-table
>
> This page shows version 1.10. But the sequence of the fields was not changed
> since version 1.0.
>
> Our LoongArch and ARM code uses version 1.07 of the specification.
> Our RISC-V code uses version 1.10 of the specification.
>
> Fixes: 7dd0b070fa09 ("hw/arm/virt-acpi-build.c: Migrate SPCR creation to common location")
> Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
> Origin: https://lore.kernel.org/qemu-devel/20260326121947.51200-1-heinrich.schuchardt@canonical.com/T/#u
> Bug-Ubuntu: https://bugs.launchpad.net/ubuntu/+source/qemu/+bug/2146419

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

Alistair

> ---
> v2:
>         Mention the different specification versions used by our code.
> v1:
>         https://lore.kernel.org/qemu-devel/20260326121947.51200-1-heinrich.schuchardt@canonical.com/T/#u
> ---
>  hw/acpi/aml-build.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c
> index 4b37405088..a999320e61 100644
> --- a/hw/acpi/aml-build.c
> +++ b/hw/acpi/aml-build.c
> @@ -2115,10 +2115,10 @@ void build_spcr(GArray *table_data, BIOSLinker *linker,
>      build_append_int_noprefix(table_data, f->stop_bits, 1);
>      /* Flow Control */
>      build_append_int_noprefix(table_data, f->flow_control, 1);
> -    /* Language */
> -    build_append_int_noprefix(table_data, f->language, 1);
>      /* Terminal Type */
>      build_append_int_noprefix(table_data, f->terminal_type, 1);
> +    /* Language */
> +    build_append_int_noprefix(table_data, f->language, 1);
>      /* PCI Device ID  */
>      build_append_int_noprefix(table_data, f->pci_device_id, 2);
>      /* PCI Vendor ID */
> --
> 2.53.0
>
>

Patchew 2.1-devel-ea86937

© 2016 - 2026 Red Hat, Inc.