It should not be possible to select and build livepatch if HAS_VMAP is
not selected. This is the case on MPU systems.

Signed-off-by: Michal Orzel <michal.orzel@amd.com>
---
 xen/common/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xen/common/Kconfig b/xen/common/Kconfig
index 2539a635f111..16936418a6e6 100644
--- a/xen/common/Kconfig
+++ b/xen/common/Kconfig
@@ -477,7 +477,7 @@ config CRYPTO
 config LIVEPATCH
 	bool "Live patching support"
 	default X86
-	depends on "$(XEN_HAS_BUILD_ID)" = "y" && SYSCTL
+	depends on "$(XEN_HAS_BUILD_ID)" = "y" && SYSCTL && HAS_VMAP
 	select CC_SPLIT_SECTIONS
 	help
 	  Allows a running Xen hypervisor to be dynamically patched using
-- 
2.43.0

On 31.07.2025 10:05, Michal Orzel wrote:
> It should not be possible to select and build livepatch if HAS_VMAP is
> not selected. This is the case on MPU systems.
> 
> Signed-off-by: Michal Orzel <michal.orzel@amd.com>

I agree this is necessary for now, so
Reviewed-by: Jan Beulich <jbeulich@suse.com>
But in principle live-patching ought to be possible without MMU as well,
just that the code will need suitably enabling? If so, it would be nice
if the description could somehow express this.

Jan

On Thu, 31 Jul 2025, Jan Beulich wrote:
> On 31.07.2025 10:05, Michal Orzel wrote:
> > It should not be possible to select and build livepatch if HAS_VMAP is
> > not selected. This is the case on MPU systems.
> > 
> > Signed-off-by: Michal Orzel <michal.orzel@amd.com>
> 
> I agree this is necessary for now, so
> Reviewed-by: Jan Beulich <jbeulich@suse.com>

Acked-by: Stefano Stabellini <sstabellini@kernel.org>

On 31/07/2025 10:22, Jan Beulich wrote:
> On 31.07.2025 10:05, Michal Orzel wrote:
>> It should not be possible to select and build livepatch if HAS_VMAP is
>> not selected. This is the case on MPU systems.
>>
>> Signed-off-by: Michal Orzel <michal.orzel@amd.com>
> 
> I agree this is necessary for now, so
> Reviewed-by: Jan Beulich <jbeulich@suse.com>
> But in principle live-patching ought to be possible without MMU as well,
> just that the code will need suitably enabling? If so, it would be nice
> if the description could somehow express this.
Yes, I agree that it can be enabled in the future with some additional changes.
I can tweak commit msg when committing:
"While technically possible to support live-patching on MPU systems, today the
code depends on vmap. However, this relationship is not reflected in Kconfig
and allows to enable live-patching on MPU, where HAS_VMAP is not selected."

~Michal

On 31.07.2025 13:10, Orzel, Michal wrote:
> On 31/07/2025 10:22, Jan Beulich wrote:
>> On 31.07.2025 10:05, Michal Orzel wrote:
>>> It should not be possible to select and build livepatch if HAS_VMAP is
>>> not selected. This is the case on MPU systems.
>>>
>>> Signed-off-by: Michal Orzel <michal.orzel@amd.com>
>>
>> I agree this is necessary for now, so
>> Reviewed-by: Jan Beulich <jbeulich@suse.com>
>> But in principle live-patching ought to be possible without MMU as well,
>> just that the code will need suitably enabling? If so, it would be nice
>> if the description could somehow express this.
> Yes, I agree that it can be enabled in the future with some additional changes.
> I can tweak commit msg when committing:
> "While technically possible to support live-patching on MPU systems, today the
> code depends on vmap. However, this relationship is not reflected in Kconfig
> and allows to enable live-patching on MPU, where HAS_VMAP is not selected."

Fine with me, thanks.

Jan