Per Stefano:

  For ARM 32-bit, I do not think we ever had many deployments,
  as most are 64-bit. Even when there are deployments, they do
  not typically use QEMU, as QEMU is less important for Xen on
  ARM compared to x86.

The QEMU project only test to cross-build Xen on Aarch64 hosts
(see 84eda110792 ("gitlab-ci: Add Xen cross-build jobs").
Since 32-bit host aren't tested, simply remove the support there.

[*] https://lore.kernel.org/qemu-devel/alpine.DEB.2.22.394.2502031438170.11632@ubuntu-linux-20-04-desktop/
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
While apparently running Xen on 32-bit hosts isn't straighforward
anymore (see [x]), we don't need to remove it ASAP, it is already
in the deprecation queue since commit 6d701c9bac1 ("meson:
Deprecate 32-bit host support").

[x] https://lore.kernel.org/qemu-devel/173d18bf-f68c-4bd5-b822-abb1c1f0c51b@suse.com/
---
 docs/about/removed-features.rst | 5 +++++
 meson.build                     | 3 ---
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/docs/about/removed-features.rst b/docs/about/removed-features.rst
index c6616ce05e5..f6ea53acc8b 100644
--- a/docs/about/removed-features.rst
+++ b/docs/about/removed-features.rst
@@ -969,6 +969,11 @@ MIPS "Trap-and-Emulate" KVM support (removed in 8.0)
 The MIPS "Trap-and-Emulate" KVM host and guest support was removed
 from Linux in 2021, and is not supported anymore by QEMU either.
 
+Xen on 32-bit ARM hosts (removed in 10.0)
+'''''''''''''''''''''''''''''''''''''''''
+
+Untested for more than 4 years.
+
 System emulator machines
 ------------------------
 
diff --git a/meson.build b/meson.build
index 8ed10b6624e..7b80d8dff09 100644
--- a/meson.build
+++ b/meson.build
@@ -308,9 +308,6 @@ if cpu == 'x86'
   xen_targets = ['i386-softmmu']
 elif cpu == 'x86_64'
   xen_targets = ['i386-softmmu', 'x86_64-softmmu']
-elif cpu == 'arm'
-  # i386 emulator provides xenpv machine type for multiple architectures
-  xen_targets = ['i386-softmmu']
 elif cpu == 'aarch64'
   # i386 emulator provides xenpv machine type for multiple architectures
   xen_targets = ['i386-softmmu', 'x86_64-softmmu', 'aarch64-softmmu']
-- 
2.47.1

On Tue, Feb 18, 2025 at 05:26:18PM +0100, Philippe Mathieu-Daudé wrote:
> Per Stefano:
> 
>   For ARM 32-bit, I do not think we ever had many deployments,
>   as most are 64-bit. Even when there are deployments, they do
>   not typically use QEMU, as QEMU is less important for Xen on
>   ARM compared to x86.
> 
> The QEMU project only test to cross-build Xen on Aarch64 hosts
> (see 84eda110792 ("gitlab-ci: Add Xen cross-build jobs").
> Since 32-bit host aren't tested, simply remove the support there.
> 
> [*] https://lore.kernel.org/qemu-devel/alpine.DEB.2.22.394.2502031438170.11632@ubuntu-linux-20-04-desktop/
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> ---
> While apparently running Xen on 32-bit hosts isn't straighforward
> anymore (see [x]), we don't need to remove it ASAP, it is already
> in the deprecation queue since commit 6d701c9bac1 ("meson:
> Deprecate 32-bit host support").
> 
> [x] https://lore.kernel.org/qemu-devel/173d18bf-f68c-4bd5-b822-abb1c1f0c51b@suse.com/
> ---
>  docs/about/removed-features.rst | 5 +++++
>  meson.build                     | 3 ---
>  2 files changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/docs/about/removed-features.rst b/docs/about/removed-features.rst
> index c6616ce05e5..f6ea53acc8b 100644
> --- a/docs/about/removed-features.rst
> +++ b/docs/about/removed-features.rst
> @@ -969,6 +969,11 @@ MIPS "Trap-and-Emulate" KVM support (removed in 8.0)
>  The MIPS "Trap-and-Emulate" KVM host and guest support was removed
>  from Linux in 2021, and is not supported anymore by QEMU either.
>  
> +Xen on 32-bit ARM hosts (removed in 10.0)
> +'''''''''''''''''''''''''''''''''''''''''
> +
> +Untested for more than 4 years.

Well, not quite, we used to have some test of Xen on armhf hosts
(one of arndale or cubietrunk, I don't remember which one we had to stop
and never start testing again) until last year, and that included tests
with qcow2 disk, so using QEMU.

But that testing infra is gone so the patch is fine:
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>

Cheers,

-- 
Anthony PERARD