diff mbox series

[v3,02/15] KVM: arm64: Provide {get, put}_page() stubs for early hyp allocator

Message ID 20211201170411.1561936-3-qperret@google.com (mailing list archive)
State New, archived
Headers show
Series KVM: arm64: Introduce kvm_share_hyp() | expand

Commit Message

Quentin Perret Dec. 1, 2021, 5:03 p.m. UTC
In nVHE protected mode, the EL2 code uses a temporary allocator during
boot while re-creating its stage-1 page-table. Unfortunately, the
hyp_vmmemap is not ready to use at this stage, so refcounting pages
is not possible. That is not currently a problem because hyp stage-1
mappings are never removed, which implies refcounting of page-table
pages is unnecessary.

In preparation for allowing hypervisor stage-1 mappings to be removed,
provide stub implementations for {get,put}_page() in the early allocator.

Signed-off-by: Quentin Perret <qperret@google.com>
---
 arch/arm64/kvm/hyp/nvhe/early_alloc.c | 5 +++++
 1 file changed, 5 insertions(+)

Comments

Will Deacon Dec. 9, 2021, 10:12 a.m. UTC | #1
On Wed, Dec 01, 2021 at 05:03:56PM +0000, Quentin Perret wrote:
> In nVHE protected mode, the EL2 code uses a temporary allocator during
> boot while re-creating its stage-1 page-table. Unfortunately, the
> hyp_vmmemap is not ready to use at this stage, so refcounting pages
> is not possible. That is not currently a problem because hyp stage-1
> mappings are never removed, which implies refcounting of page-table
> pages is unnecessary.
> 
> In preparation for allowing hypervisor stage-1 mappings to be removed,
> provide stub implementations for {get,put}_page() in the early allocator.
> 
> Signed-off-by: Quentin Perret <qperret@google.com>
> ---
>  arch/arm64/kvm/hyp/nvhe/early_alloc.c | 5 +++++
>  1 file changed, 5 insertions(+)

Acked-by: Will Deacon <will@kernel.org>

Will
diff mbox series

Patch

diff --git a/arch/arm64/kvm/hyp/nvhe/early_alloc.c b/arch/arm64/kvm/hyp/nvhe/early_alloc.c
index 1306c430ab87..00de04153cc6 100644
--- a/arch/arm64/kvm/hyp/nvhe/early_alloc.c
+++ b/arch/arm64/kvm/hyp/nvhe/early_alloc.c
@@ -43,6 +43,9 @@  void *hyp_early_alloc_page(void *arg)
 	return hyp_early_alloc_contig(1);
 }
 
+static void hyp_early_alloc_get_page(void *addr) { }
+static void hyp_early_alloc_put_page(void *addr) { }
+
 void hyp_early_alloc_init(void *virt, unsigned long size)
 {
 	base = cur = (unsigned long)virt;
@@ -51,4 +54,6 @@  void hyp_early_alloc_init(void *virt, unsigned long size)
 	hyp_early_alloc_mm_ops.zalloc_page = hyp_early_alloc_page;
 	hyp_early_alloc_mm_ops.phys_to_virt = hyp_phys_to_virt;
 	hyp_early_alloc_mm_ops.virt_to_phys = hyp_virt_to_phys;
+	hyp_early_alloc_mm_ops.get_page = hyp_early_alloc_get_page;
+	hyp_early_alloc_mm_ops.put_page = hyp_early_alloc_put_page;
 }