KVM: arm64: Disintegrate SPSR array

As we're about to move SPSR_EL1 into the VNCR page, we need to
disassociate it from the rest of the 32bit cruft. Let's break
the array into individual fields.
Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>

arch/arm64/include/asm/kvm_emulate.h

@@ -176,7 +176,7 @@ static inline unsigned long vcpu_read_spsr(const struct kvm_vcpu *vcpu)
 	if (vcpu->arch.sysregs_loaded_on_cpu)
 		return read_sysreg_el1(SYS_SPSR);
 	else
-		return vcpu->arch.ctxt.spsr[KVM_SPSR_EL1];
+		return vcpu->arch.ctxt.spsr_el1;
 }
 
 static inline void vcpu_write_spsr(struct kvm_vcpu *vcpu, unsigned long v)
@@ -189,7 +189,7 @@ static inline void vcpu_write_spsr(struct kvm_vcpu *vcpu, unsigned long v)
 	if (vcpu->arch.sysregs_loaded_on_cpu)
 		write_sysreg_el1(v, SYS_SPSR);
 	else
-		vcpu->arch.ctxt.spsr[KVM_SPSR_EL1] = v;
+		vcpu->arch.ctxt.spsr_el1 = v;
 }
 
 /*

arch/arm64/include/asm/kvm_host.h

@@ -241,7 +241,11 @@ enum vcpu_sysreg {
 struct kvm_cpu_context {
 	struct user_pt_regs regs;	/* sp = sp_el0 */
 
-	u64	spsr[KVM_NR_SPSR];
+	u64	spsr_el1;		/* aka spsr_svc */
+	u64	spsr_abt;
+	u64	spsr_und;
+	u64	spsr_irq;
+	u64	spsr_fiq;
 
 	struct user_fpsimd_state fp_regs;
 

arch/arm64/kvm/guest.c

@@ -134,11 +134,20 @@ static void *core_reg_addr(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 	case KVM_REG_ARM_CORE_REG(elr_el1):
 		return __ctxt_sys_reg(&vcpu->arch.ctxt, ELR_EL1);
 
-	case KVM_REG_ARM_CORE_REG(spsr[0]) ...
-	     KVM_REG_ARM_CORE_REG(spsr[KVM_NR_SPSR - 1]):
-		off -= KVM_REG_ARM_CORE_REG(spsr[0]);
-		off /= 2;
-		return &vcpu->arch.ctxt.spsr[off];
+	case KVM_REG_ARM_CORE_REG(spsr[KVM_SPSR_EL1]):
+		return &vcpu->arch.ctxt.spsr_el1;
+
+	case KVM_REG_ARM_CORE_REG(spsr[KVM_SPSR_ABT]):
+		return &vcpu->arch.ctxt.spsr_abt;
+
+	case KVM_REG_ARM_CORE_REG(spsr[KVM_SPSR_UND]):
+		return &vcpu->arch.ctxt.spsr_und;
+
+	case KVM_REG_ARM_CORE_REG(spsr[KVM_SPSR_IRQ]):
+		return &vcpu->arch.ctxt.spsr_irq;
+
+	case KVM_REG_ARM_CORE_REG(spsr[KVM_SPSR_FIQ]):
+		return &vcpu->arch.ctxt.spsr_fiq;
 
 	case KVM_REG_ARM_CORE_REG(fp_regs.vregs[0]) ...
 	     KVM_REG_ARM_CORE_REG(fp_regs.vregs[31]):

arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h

@@ -48,7 +48,7 @@ static inline void __sysreg_save_el1_state(struct kvm_cpu_context *ctxt)
 
 	ctxt_sys_reg(ctxt, SP_EL1)	= read_sysreg(sp_el1);
 	ctxt_sys_reg(ctxt, ELR_EL1)	= read_sysreg_el1(SYS_ELR);
-	ctxt->spsr[KVM_SPSR_EL1]	= read_sysreg_el1(SYS_SPSR);
+	ctxt->spsr_el1			= read_sysreg_el1(SYS_SPSR);
 }
 
 static inline void __sysreg_save_el2_return_state(struct kvm_cpu_context *ctxt)
@@ -127,7 +127,7 @@ static inline void __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt)
 
 	write_sysreg(ctxt_sys_reg(ctxt, SP_EL1),	sp_el1);
 	write_sysreg_el1(ctxt_sys_reg(ctxt, ELR_EL1),	SYS_ELR);
-	write_sysreg_el1(ctxt->spsr[KVM_SPSR_EL1],	SYS_SPSR);
+	write_sysreg_el1(ctxt->spsr_el1,		SYS_SPSR);
 }
 
 static inline void __sysreg_restore_el2_return_state(struct kvm_cpu_context *ctxt)
@@ -158,17 +158,13 @@ static inline void __sysreg_restore_el2_return_state(struct kvm_cpu_context *ctx
 
 static inline void __sysreg32_save_state(struct kvm_vcpu *vcpu)
 {
-	u64 *spsr;
-
 	if (!vcpu_el1_is_32bit(vcpu))
 		return;
 
-	spsr = vcpu->arch.ctxt.spsr;
-
-	spsr[KVM_SPSR_ABT] = read_sysreg(spsr_abt);
-	spsr[KVM_SPSR_UND] = read_sysreg(spsr_und);
-	spsr[KVM_SPSR_IRQ] = read_sysreg(spsr_irq);
-	spsr[KVM_SPSR_FIQ] = read_sysreg(spsr_fiq);
+	vcpu->arch.ctxt.spsr_abt = read_sysreg(spsr_abt);
+	vcpu->arch.ctxt.spsr_und = read_sysreg(spsr_und);
+	vcpu->arch.ctxt.spsr_irq = read_sysreg(spsr_irq);
+	vcpu->arch.ctxt.spsr_fiq = read_sysreg(spsr_fiq);
 
 	__vcpu_sys_reg(vcpu, DACR32_EL2) = read_sysreg(dacr32_el2);
 	__vcpu_sys_reg(vcpu, IFSR32_EL2) = read_sysreg(ifsr32_el2);
@@ -179,17 +175,13 @@ static inline void __sysreg32_save_state(struct kvm_vcpu *vcpu)
 
 static inline void __sysreg32_restore_state(struct kvm_vcpu *vcpu)
 {
-	u64 *spsr;
-
 	if (!vcpu_el1_is_32bit(vcpu))
 		return;
 
-	spsr = vcpu->arch.ctxt.spsr;
-
-	write_sysreg(spsr[KVM_SPSR_ABT], spsr_abt);
-	write_sysreg(spsr[KVM_SPSR_UND], spsr_und);
-	write_sysreg(spsr[KVM_SPSR_IRQ], spsr_irq);
-	write_sysreg(spsr[KVM_SPSR_FIQ], spsr_fiq);
+	write_sysreg(vcpu->arch.ctxt.spsr_abt, spsr_abt);
+	write_sysreg(vcpu->arch.ctxt.spsr_und, spsr_und);
+	write_sysreg(vcpu->arch.ctxt.spsr_irq, spsr_irq);
+	write_sysreg(vcpu->arch.ctxt.spsr_fiq, spsr_fiq);
 
 	write_sysreg(__vcpu_sys_reg(vcpu, DACR32_EL2), dacr32_el2);
 	write_sysreg(__vcpu_sys_reg(vcpu, IFSR32_EL2), ifsr32_el2);

arch/arm64/kvm/regmap.c

@@ -147,8 +147,20 @@ unsigned long vcpu_read_spsr32(const struct kvm_vcpu *vcpu)
 {
 	int spsr_idx = vcpu_spsr32_mode(vcpu);
 
-	if (!vcpu->arch.sysregs_loaded_on_cpu)
-		return vcpu->arch.ctxt.spsr[spsr_idx];
+	if (!vcpu->arch.sysregs_loaded_on_cpu) {
+		switch (spsr_idx) {
+		case KVM_SPSR_SVC:
+			return vcpu->arch.ctxt.spsr_el1;
+		case KVM_SPSR_ABT:
+			return vcpu->arch.ctxt.spsr_abt;
+		case KVM_SPSR_UND:
+			return vcpu->arch.ctxt.spsr_und;
+		case KVM_SPSR_IRQ:
+			return vcpu->arch.ctxt.spsr_irq;
+		case KVM_SPSR_FIQ:
+			return vcpu->arch.ctxt.spsr_fiq;
+		}
+	}
 
 	switch (spsr_idx) {
 	case KVM_SPSR_SVC:
@@ -171,7 +183,24 @@ void vcpu_write_spsr32(struct kvm_vcpu *vcpu, unsigned long v)
 	int spsr_idx = vcpu_spsr32_mode(vcpu);
 
 	if (!vcpu->arch.sysregs_loaded_on_cpu) {
-		vcpu->arch.ctxt.spsr[spsr_idx] = v;
+		switch (spsr_idx) {
+		case KVM_SPSR_SVC:
+			vcpu->arch.ctxt.spsr_el1 = v;
+			break;
+		case KVM_SPSR_ABT:
+			vcpu->arch.ctxt.spsr_abt = v;
+			break;
+		case KVM_SPSR_UND:
+			vcpu->arch.ctxt.spsr_und = v;
+			break;
+		case KVM_SPSR_IRQ:
+			vcpu->arch.ctxt.spsr_irq = v;
+			break;
+		case KVM_SPSR_FIQ:
+			vcpu->arch.ctxt.spsr_fiq = v;
+			break;
+		}
+
 		return;
 	}