[PATCH] KVM: arm64: Remove PAGE_SIZE alignment for hyp event ELF sections

[PATCH] KVM: arm64: Remove PAGE_SIZE alignment for hyp event ELF sections

[Vincent Donnefort]

.hyp.event_ids is mapped as part of .hyp.rodata. As a consequence this
section does not need any page-alignment. Remove it to save a page worth
of memory.

Fixes: 0a90fbc8a170 ("KVM: arm64: Add event support to the nVHE/pKVM hyp and trace remote")
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
---
 arch/arm64/kernel/vmlinux.lds.S   | 2 +-
 arch/arm64/kvm/hyp/nvhe/hyp.lds.S | 1 -
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S
index af1d72020976..c0b090db8be4 100644
--- a/arch/arm64/kernel/vmlinux.lds.S
+++ b/arch/arm64/kernel/vmlinux.lds.S
@@ -15,7 +15,7 @@
 
 #ifdef CONFIG_NVHE_EL2_TRACING
 #define HYPERVISOR_EVENT_IDS 					\
-	. = ALIGN(PAGE_SIZE);					\
+	. = ALIGN(SZ_8);					\
 	__hyp_event_ids_start = .;				\
 	*(HYP_SECTION_NAME(.event_ids))				\
 	__hyp_event_ids_end = .;
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp.lds.S b/arch/arm64/kvm/hyp/nvhe/hyp.lds.S
index 7a02837203d1..89222425359a 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp.lds.S
+++ b/arch/arm64/kvm/hyp/nvhe/hyp.lds.S
@@ -17,7 +17,6 @@ SECTIONS {
 	HYP_SECTION(.data..ro_after_init)
 	HYP_SECTION(.rodata)
 #ifdef CONFIG_NVHE_EL2_TRACING
-	. = ALIGN(PAGE_SIZE);
 	BEGIN_HYP_SECTION(.event_ids)
 		*(SORT(.hyp.event_ids.*))
 	END_HYP_SECTION

base-commit: 93f51579e7df248780214094418f205253383cc5
-- 
2.56.0.rc1.310.g51773c2048-goog

Re: [PATCH] KVM: arm64: Remove PAGE_SIZE alignment for hyp event ELF sections

[Fuad Tabba]

Hi Vincent,

On Thu, 24 Sep 2026 10:51:54 +0100, Vincent Donnefort
<vdonnefort@google.com> wrote:
> .hyp.event_ids is mapped as part of .hyp.rodata. As a consequence this
> section does not need any page-alignment. Remove it to save a page worth
> of memory.
>
> Fixes: 0a90fbc8a170 ("KVM: arm64: Add event support to the nVHE/pKVM hyp and trace remote")

Could you either drop the Fixes: tag or say in the message what goes
wrong without this patch? As it stands the message describes a
one-page saving, and the tag makes it a candidate for stable.

With that:
Reviewed-by: Fuad Tabba <fuad.tabba@linux.dev>

Tested with the hypervisor remote ftrace selftests, in pKVM and in nVHE:
Tested-by: Fuad Tabba <fuad.tabba@linux.dev>

Cheers,
/fuad

Re: [PATCH] KVM: arm64: Remove PAGE_SIZE alignment for hyp event ELF sections

[Marc Zyngier]

On Thu, 24 Sep 2026 17:14:54 +0100,
Fuad Tabba <fuad.tabba@linux.dev> wrote:
> 
> Hi Vincent,
> 
> On Thu, 24 Sep 2026 10:51:54 +0100, Vincent Donnefort
> <vdonnefort@google.com> wrote:
> > .hyp.event_ids is mapped as part of .hyp.rodata. As a consequence this
> > section does not need any page-alignment. Remove it to save a page worth
> > of memory.
> >
> > Fixes: 0a90fbc8a170 ("KVM: arm64: Add event support to the nVHE/pKVM hyp and trace remote")
> 
> Could you either drop the Fixes: tag or say in the message what goes
> wrong without this patch? As it stands the message describes a
> one-page saving, and the tag makes it a candidate for stable.

I've dropped the tag when applying the patch.

Thanks,

	M.

-- 
Jazz isn't dead. It just smells funny.

Re: [PATCH] KVM: arm64: Remove PAGE_SIZE alignment for hyp event ELF sections

[Marc Zyngier]

On Thu, 24 Sep 2026 10:51:54 +0100, Vincent Donnefort wrote:
> .hyp.event_ids is mapped as part of .hyp.rodata. As a consequence this
> section does not need any page-alignment. Remove it to save a page worth
> of memory.

Applied to next, thanks!

[1/1] KVM: arm64: Remove PAGE_SIZE alignment for hyp event ELF sections
      commit: 8642afb74be6de014e49937c2c4de7576f45531c

Cheers,

	M.
-- 
Without deviation from the norm, progress is not possible.