[RFC PATCH 16/26] kvm: arm64: Add offset for hyp VA <-> PA conversion

[David Brazdil <dbrazdil@google.com>]

Add a host-initialized constant to KVM nVHE hyp code for converting
between EL2 linear map virtual addresses and physical addresses.
Also add `__hyp_pa` macro that performs the conversion.

Signed-off-by: David Brazdil <dbrazdil@google.com>
---
 arch/arm64/kvm/arm.c           | 15 +++++++++++++++
 arch/arm64/kvm/hyp/nvhe/psci.c |  3 +++
 2 files changed, 18 insertions(+)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index cedec793da64..580d4a656a7b 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1484,6 +1484,20 @@ static inline void hyp_cpu_pm_exit(void)
 }
 #endif
 
+static void init_hyp_physvirt_offset(void)
+{
+	extern s64 kvm_nvhe_sym(hyp_physvirt_offset);
+	unsigned long kern_vaddr, hyp_vaddr, paddr;
+
+	/* Check that kvm_arm_hyp_percpu_base has been set. */
+	BUG_ON(kvm_arm_hyp_percpu_base[0] == 0);
+
+	kern_vaddr = kvm_arm_hyp_percpu_base[0];
+	hyp_vaddr = kern_hyp_va(kern_vaddr);
+	paddr = __pa(kern_vaddr);
+	CHOOSE_NVHE_SYM(hyp_physvirt_offset) = (s64)paddr - (s64)hyp_vaddr;
+}
+
 static void init_cpu_logical_map(void)
 {
 	extern u64 kvm_nvhe_sym(__cpu_logical_map)[NR_CPUS];
@@ -1686,6 +1700,7 @@ static int init_hyp_mode(void)
 		}
 	}
 
+	init_hyp_physvirt_offset();
 	init_cpu_logical_map();
 	init_psci();
 
diff --git a/arch/arm64/kvm/hyp/nvhe/psci.c b/arch/arm64/kvm/hyp/nvhe/psci.c
index 8f779560ab6f..3eafcf48a29b 100644
--- a/arch/arm64/kvm/hyp/nvhe/psci.c
+++ b/arch/arm64/kvm/hyp/nvhe/psci.c
@@ -16,6 +16,9 @@
 /* Config options set by the host. */
 u32 kvm_host_psci_version = PSCI_VERSION(0, 0);
 u32 kvm_host_psci_function_id[PSCI_FN_MAX];
+s64 hyp_physvirt_offset;
+
+#define __hyp_pa(x) ((phys_addr_t)(x) + hyp_physvirt_offset)
 
 static u64 get_psci_func_id(struct kvm_cpu_context *host_ctxt)
 {
-- 
2.29.1.341.ge80a0c044ae-goog