[PATCH v2 02/15] KVM: arm64: Provide {get,put}_page() stubs for early hyp allocator

Quentin Perret
2021-10-19T12:13:17Z

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(+)

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;
}
--
2.33.0.1079.g6e70778dc9-goog