[PATCH 49/89] KVM: arm64: Add hyp per_cpu variable to track current physical cpu number

[Will Deacon]

From: Fuad Tabba <tabba at google.com>

Hyp cannot trust the equivalent variable at the host.

Signed-off-by: Fuad Tabba <tabba at google.com>
---
 arch/arm64/include/asm/kvm_hyp.h  | 3 +++
 arch/arm64/kvm/arm.c              | 4 ++++
 arch/arm64/kvm/hyp/nvhe/hyp-smp.c | 2 ++
 3 files changed, 9 insertions(+)

diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h
index 4adf7c2a77bd..e38869e88019 100644
--- a/arch/arm64/include/asm/kvm_hyp.h
+++ b/arch/arm64/include/asm/kvm_hyp.h
@@ -15,6 +15,9 @@
 DECLARE_PER_CPU(struct kvm_cpu_context, kvm_hyp_ctxt);
 DECLARE_PER_CPU(unsigned long, kvm_hyp_vector);
 DECLARE_PER_CPU(struct kvm_nvhe_init_params, kvm_init_params);
+DECLARE_PER_CPU(int, hyp_cpu_number);
+
+#define hyp_smp_processor_id() (__this_cpu_read(hyp_cpu_number))
 
 #define read_sysreg_elx(r,nvh,vh)					\
 	({								\
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 514519563976..3bb379f15c07 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -52,6 +52,7 @@ DECLARE_KVM_HYP_PER_CPU(unsigned long, kvm_hyp_vector);
 
 static DEFINE_PER_CPU(unsigned long, kvm_arm_hyp_stack_page);
 DECLARE_KVM_NVHE_PER_CPU(struct kvm_nvhe_init_params, kvm_init_params);
+DECLARE_KVM_NVHE_PER_CPU(int, hyp_cpu_number);
 
 static bool vgic_present;
 
@@ -1487,6 +1488,9 @@ static void cpu_prepare_hyp_mode(int cpu)
 {
 	struct kvm_nvhe_init_params *params = per_cpu_ptr_nvhe_sym(kvm_init_params, cpu);
 	unsigned long tcr;
+	int *hyp_cpu_number_ptr = per_cpu_ptr_nvhe_sym(hyp_cpu_number, cpu);
+
+	*hyp_cpu_number_ptr = cpu;
 
 	/*
 	 * Calculate the raw per-cpu offset without a translation from the
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-smp.c b/arch/arm64/kvm/hyp/nvhe/hyp-smp.c
index 04d194583f1e..9fcb92abd0b5 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-smp.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-smp.c
@@ -8,6 +8,8 @@
 #include <asm/kvm_hyp.h>
 #include <asm/kvm_mmu.h>
 
+DEFINE_PER_CPU(int, hyp_cpu_number);
+
 /*
  * nVHE copy of data structures tracking available CPU cores.
  * Only entries for CPUs that were online at KVM init are populated.
-- 
2.36.1.124.g0e6072fb45-goog