[PATCH v3 08/23] KVM: arm64: Share system register code with s390

[Steffen Eiden <seiden@linux.ibm.com>]

Mark functions that s390 can use to implement system registers for arm
on s390 guests as shared functions. The new shared functionality covers
system register infrastructure for KVM, Pointer auth checks and
shareable parts of the SVE register API. In order to reduce the number
of shared sections more code than s390 requires is shared. This is no
problem as for the shared code unused function checking is disabled.

Co-developed-by: Andreas Grapentin <gra@linux.ibm.com>
Signed-off-by: Andreas Grapentin <gra@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
 arch/arm64/kvm/arm.c      |  3 +++
 arch/arm64/kvm/guest.c    | 11 +++++++----
 arch/arm64/kvm/sys_regs.c | 27 +++++++++++++++++++++++++++
 3 files changed, 37 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 157bf4b81202..d83df5ff68f4 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -366,6 +366,7 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
 	kvm_arm_teardown_hypercalls(kvm);
 }
 
+#if ARM64_S390_COMMON == 1
 static bool kvm_has_full_ptr_auth(void)
 {
 	bool apa, gpa, api, gpi, apa3, gpa3;
@@ -400,6 +401,8 @@ static bool kvm_has_full_ptr_auth(void)
 		(apa + api + apa3) == 1);
 }
 
+#endif /* ARM64_S390_COMMON == 1 */
+
 int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 {
 	int r;
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 878ea4500c5c..26ec4751e17e 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -307,12 +307,12 @@ static int set_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 	return err;
 }
 
-#endif /* ARM64_S390_COMMON == 1 */
-
 #define vq_word(vq) (((vq) - SVE_VQ_MIN) / 64)
 #define vq_mask(vq) ((u64)1 << ((vq) - SVE_VQ_MIN) % 64)
 #define vq_present(vqs, vq) (!!((vqs)[vq_word(vq)] & vq_mask(vq)))
 
+#endif /* ARM64_S390_COMMON == 1 */
+
 static int get_sve_vls(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 {
 	unsigned int max_vq, vq;
@@ -383,6 +383,7 @@ static int set_sve_vls(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 	return 0;
 }
 
+#if ARM64_S390_COMMON == 1
 #define SVE_REG_SLICE_SHIFT	0
 #define SVE_REG_SLICE_BITS	5
 #define SVE_REG_ID_SHIFT	(SVE_REG_SLICE_SHIFT + SVE_REG_SLICE_BITS)
@@ -399,6 +400,8 @@ static int set_sve_vls(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 #define KVM_SVE_ZREG_SIZE KVM_REG_SIZE(KVM_REG_ARM64_SVE_ZREG(0, 0))
 #define KVM_SVE_PREG_SIZE KVM_REG_SIZE(KVM_REG_ARM64_SVE_PREG(0, 0))
 
+#endif /* ARM64_S390_COMMON == 1 */
+
 /*
  * Number of register slices required to cover each whole SVE register.
  * NOTE: Only the first slice every exists, for now.
@@ -595,8 +598,6 @@ static unsigned long num_core_regs(const struct kvm_vcpu *vcpu)
 	return copy_core_reg_indices(vcpu, NULL);
 }
 
-#endif /* ARM64_S390_COMMON == 1 */
-
 static unsigned long num_sve_regs(const struct kvm_vcpu *vcpu)
 {
 	const unsigned int slices = vcpu_sve_slices(vcpu);
@@ -658,6 +659,8 @@ static int copy_sve_reg_indices(const struct kvm_vcpu *vcpu,
 	return num_regs;
 }
 
+#endif /* ARM64_S390_COMMON == 1 */
+
 /**
  * kvm_arm_num_regs - how many registers do we present via KVM_GET_ONE_REG
  * @vcpu: the vCPU pointer
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index e71c1b169b49..fa1ed13daeb9 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -45,6 +45,7 @@
  * 64bit interface.
  */
 
+#if ARM64_S390_COMMON == 1
 static u64 sys_reg_to_index(const struct sys_reg_desc *reg);
 static int set_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
 		      u64 val);
@@ -82,6 +83,8 @@ static bool write_to_read_only(struct kvm_vcpu *vcpu,
 			"sys_reg write to read-only register");
 }
 
+#endif /* ARM64_S390_COMMON == 1 */
+
 enum sr_loc_attr {
 	SR_LOC_MEMORY	= 0,	  /* Register definitely in memory */
 	SR_LOC_LOADED	= BIT(0), /* Register on CPU, unless it cannot */
@@ -428,6 +431,7 @@ void vcpu_write_sys_reg(struct kvm_vcpu *vcpu, u64 val, enum vcpu_sysreg reg)
 	__vcpu_assign_sys_reg(vcpu, reg, val);
 }
 
+#if ARM64_S390_COMMON == 1
 /* CSSELR values; used to index KVM_REG_ARM_DEMUX_ID_CCSIDR */
 #define CSSELR_MAX 14
 
@@ -533,6 +537,8 @@ static bool access_rw(struct kvm_vcpu *vcpu,
 	return true;
 }
 
+#endif /* ARM64_S390_COMMON == 1 */
+
 /*
  * See note at ARMv7 ARM B1.14.4 (TL;DR: S/W ops are not easily virtualized).
  */
@@ -800,6 +806,7 @@ static bool access_gicv5_ppi_enabler(struct kvm_vcpu *vcpu,
 	return true;
 }
 
+#if ARM64_S390_COMMON == 1
 static bool trap_raz_wi(struct kvm_vcpu *vcpu,
 			struct sys_reg_params *p,
 			const struct sys_reg_desc *r)
@@ -853,6 +860,8 @@ static bool trap_oslsr_el1(struct kvm_vcpu *vcpu,
 	return true;
 }
 
+#endif /* ARM64_S390_COMMON == 1 */
+
 static int set_oslsr_el1(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
 			 u64 val)
 {
@@ -1012,6 +1021,7 @@ static u64 reset_actlr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
 	return actlr;
 }
 
+#if ARM64_S390_COMMON == 1
 static u64 reset_mpidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
 {
 	u64 mpidr = kvm_calculate_mpidr(vcpu);
@@ -1020,6 +1030,8 @@ static u64 reset_mpidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
 	return mpidr;
 }
 
+#endif /* ARM64_S390_COMMON == 1 */
+
 static unsigned int hidden_visibility(const struct kvm_vcpu *vcpu,
 				      const struct sys_reg_desc *r)
 {
@@ -1589,6 +1601,7 @@ static int set_pmcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r,
 #define AMU_AMEVCNTR1_EL0(n) { SYS_DESC(SYS_AMEVCNTR1_EL0(n)), undef_access }
 #define AMU_AMEVTYPER1_EL0(n) { SYS_DESC(SYS_AMEVTYPER1_EL0(n)), undef_access }
 
+#if ARM64_S390_COMMON == 1
 static unsigned int ptrauth_visibility(const struct kvm_vcpu *vcpu,
 			const struct sys_reg_desc *rd)
 {
@@ -1609,6 +1622,8 @@ static unsigned int ptrauth_visibility(const struct kvm_vcpu *vcpu,
 	__PTRAUTH_KEY(k ## KEYLO_EL1),					\
 	__PTRAUTH_KEY(k ## KEYHI_EL1)
 
+#endif /* ARM64_S390_COMMON == 1 */
+
 static bool access_arch_timer(struct kvm_vcpu *vcpu,
 			      struct sys_reg_params *p,
 			      const struct sys_reg_desc *r)
@@ -1906,6 +1921,7 @@ static int arm64_check_features(struct kvm_vcpu *vcpu,
 	return 0;
 }
 
+#if ARM64_S390_COMMON == 1
 static u8 pmuver_to_perfmon(u8 pmuver)
 {
 	switch (pmuver) {
@@ -2840,6 +2856,8 @@ static bool bad_redir_trap(struct kvm_vcpu *vcpu,
 	.val = 0,				\
 }
 
+#endif /* ARM64_S390_COMMON == 1 */
+
 static bool access_sp_el1(struct kvm_vcpu *vcpu,
 			  struct sys_reg_params *p,
 			  const struct sys_reg_desc *r)
@@ -3212,6 +3230,7 @@ static void init_imp_id_regs(void)
 	boot_cpu_aidr_val = read_sysreg(aidr_el1);
 }
 
+#if ARM64_S390_COMMON == 1
 static u64 reset_imp_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
 {
 	switch (reg_to_encoding(r)) {
@@ -3269,6 +3288,8 @@ static int set_imp_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r,
 	.val = mask,					\
 	}
 
+#endif /* ARM64_S390_COMMON == 1 */
+
 static u64 reset_mdcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
 {
 	__vcpu_assign_sys_reg(vcpu, r->reg, vcpu->kvm->arch.nr_pmu_counters);
@@ -4833,6 +4854,7 @@ static const struct sys_reg_desc cp15_64_regs[] = {
 	{ SYS_DESC(SYS_AARCH32_CNTVCTSS),     access_arch_timer },
 };
 
+#if ARM64_S390_COMMON == 1
 static bool check_sysreg_table(const struct sys_reg_desc *table, unsigned int n,
 			       bool reset_check)
 {
@@ -4882,6 +4904,8 @@ static void perform_access(struct kvm_vcpu *vcpu,
 		kvm_incr_pc(vcpu);
 }
 
+#endif /* ARM64_S390_COMMON == 1 */
+
 int kvm_handle_cp14_load_store(struct kvm_vcpu *vcpu)
 {
 	kvm_inject_undefined(vcpu);
@@ -5416,6 +5440,7 @@ int kvm_handle_sys_reg(struct kvm_vcpu *vcpu)
 	return 1;
 }
 
+#if ARM64_S390_COMMON == 1
 static void reset_vm_ftr_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *reg)
 {
 	u32 id = reg_to_encoding(reg);
@@ -5757,6 +5782,8 @@ int kvm_arm_copy_sys_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
 	return write_demux_regids(uindices);
 }
 
+#endif /* ARM64_S390_COMMON == 1 */
+
 #define KVM_ARM_FEATURE_ID_RANGE_INDEX(r)			\
 	KVM_ARM_FEATURE_ID_RANGE_IDX(sys_reg_Op0(r),		\
 		sys_reg_Op1(r),					\

-- 
2.56.0