kvm: arm64: Add helpers for accessing nVHE hyp per-cpu vars

Defining a per-CPU variable in hyp/nvhe will result in its name being
prefixed with __kvm_nvhe_. Add helpers for declaring these variables
in kernel proper and accessing them with this_cpu_ptr and per_cpu_ptr.

Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200922204910.7265-7-dbrazdil@google.com

diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index cf94566..911d917 100644 (file)
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -54,9 +54,21 @@
        DECLARE_KVM_VHE_SYM(sym);               \
        DECLARE_KVM_NVHE_SYM(sym)
 
+#define DECLARE_KVM_VHE_PER_CPU(type, sym)     \
+       DECLARE_PER_CPU(type, sym)
+#define DECLARE_KVM_NVHE_PER_CPU(type, sym)    \
+       DECLARE_PER_CPU(type, kvm_nvhe_sym(sym))
+
+#define DECLARE_KVM_HYP_PER_CPU(type, sym)     \
+       DECLARE_KVM_VHE_PER_CPU(type, sym);     \
+       DECLARE_KVM_NVHE_PER_CPU(type, sym)
+
 #define CHOOSE_VHE_SYM(sym)    sym
 #define CHOOSE_NVHE_SYM(sym)   kvm_nvhe_sym(sym)
 
+#define this_cpu_ptr_nvhe_sym(sym)     this_cpu_ptr(&kvm_nvhe_sym(sym))
+#define per_cpu_ptr_nvhe_sym(sym, cpu) per_cpu_ptr(&kvm_nvhe_sym(sym), cpu)
+
 #ifndef __KVM_NVHE_HYPERVISOR__
 /*
  * BIG FAT WARNINGS:
@@ -69,12 +81,21 @@
  * - Don't let the nVHE hypervisor have access to this, as it will
  *   pick the *wrong* symbol (yes, it runs at EL2...).
  */
-#define CHOOSE_HYP_SYM(sym)    (is_kernel_in_hyp_mode() ? CHOOSE_VHE_SYM(sym) \
+#define CHOOSE_HYP_SYM(sym)            (is_kernel_in_hyp_mode()        \
+                                          ? CHOOSE_VHE_SYM(sym)        \
                                           : CHOOSE_NVHE_SYM(sym))
+#define this_cpu_ptr_hyp_sym(sym)      (is_kernel_in_hyp_mode()        \
+                                          ? this_cpu_ptr(&sym)         \
+                                          : this_cpu_ptr_nvhe_sym(sym))
+#define per_cpu_ptr_hyp_sym(sym, cpu)  (is_kernel_in_hyp_mode()        \
+                                          ? per_cpu_ptr(&sym, cpu)     \
+                                          : per_cpu_ptr_nvhe_sym(sym, cpu))
 #else
 /* The nVHE hypervisor shouldn't even try to access anything */
 extern void *__nvhe_undefined_symbol;
-#define CHOOSE_HYP_SYM(sym)    __nvhe_undefined_symbol
+#define CHOOSE_HYP_SYM(sym)            __nvhe_undefined_symbol
+#define this_cpu_ptr_hyp_sym(sym)      (&__nvhe_undefined_symbol)
+#define per_cpu_ptr_hyp_sym(sym, cpu)  (&__nvhe_undefined_symbol)
 #endif
 
 /* Translate a kernel address @ptr into its equivalent linear mapping */