[RFC PATCH 09/45] KVM: arm64: pkvm: Add pkvm_create_hyp_device_mapping()

[Jean-Philippe Brucker]

Add a function to map a MMIO region in the hypervisor and remove it from
the host. Hypervisor device drivers use this to reserve their regions
during setup.

Signed-off-by: Jean-Philippe Brucker <jean-philippe at linaro.org>
---
 arch/arm64/kvm/hyp/include/nvhe/mm.h |  1 +
 arch/arm64/kvm/hyp/nvhe/setup.c      | 17 +++++++++++++++++
 2 files changed, 18 insertions(+)

diff --git a/arch/arm64/kvm/hyp/include/nvhe/mm.h b/arch/arm64/kvm/hyp/include/nvhe/mm.h
index d5ec972b5c1e..84db840f2057 100644
--- a/arch/arm64/kvm/hyp/include/nvhe/mm.h
+++ b/arch/arm64/kvm/hyp/include/nvhe/mm.h
@@ -27,5 +27,6 @@ int __pkvm_create_private_mapping(phys_addr_t phys, size_t size,
 				  enum kvm_pgtable_prot prot,
 				  unsigned long *haddr);
 int pkvm_alloc_private_va_range(size_t size, unsigned long *haddr);
+int pkvm_create_hyp_device_mapping(u64 base, u64 size, void __iomem *haddr);
 
 #endif /* __KVM_HYP_MM_H */
diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c
index 629e74c46b35..de7d60c3c20b 100644
--- a/arch/arm64/kvm/hyp/nvhe/setup.c
+++ b/arch/arm64/kvm/hyp/nvhe/setup.c
@@ -259,6 +259,23 @@ static int fix_host_ownership(void)
 	return 0;
 }
 
+/* Map the MMIO region into the hypervisor and remove it from host */
+int pkvm_create_hyp_device_mapping(u64 base, u64 size, void __iomem *haddr)
+{
+	int ret;
+
+	ret = __pkvm_create_private_mapping(base, size, PAGE_HYP_DEVICE, haddr);
+	if (ret)
+		return ret;
+
+	/* lock not needed during setup */
+	ret = host_stage2_set_owner_locked(base, size, PKVM_ID_HYP);
+	if (ret)
+		return ret;
+
+	return ret;
+}
+
 static int fix_hyp_pgtable_refcnt(void)
 {
 	struct kvm_pgtable_walker walker = {
-- 
2.39.0