KVM: arm64: Make struct kvm_regs userspace-only

struct kvm_regs is used by userspace to indicate which register gets
accessed by the {GET,SET}_ONE_REG API. But as we're about to refactor
the layout of the in-kernel register structures, we need the kernel to
move away from it.

Let's make kvm_regs userspace only, and let the kernel map it to its own
internal representation.

Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>

2 files changed, 19 insertions, 11 deletions

diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index 269a76cd51ff..cd607999abc2 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -124,12 +124,12 @@ static inline void vcpu_set_vsesr(struct kvm_vcpu *vcpu, u64 vsesr)
 
 static __always_inline unsigned long *vcpu_pc(const struct kvm_vcpu *vcpu)
 {
-	return (unsigned long *)&vcpu_gp_regs(vcpu)->regs.pc;
+	return (unsigned long *)&vcpu_gp_regs(vcpu)->pc;
 }
 
 static inline unsigned long *__vcpu_elr_el1(const struct kvm_vcpu *vcpu)
 {
-	return (unsigned long *)&vcpu_gp_regs(vcpu)->elr_el1;
+	return (unsigned long *)&vcpu->arch.ctxt.elr_el1;
 }
 
 static inline unsigned long vcpu_read_elr_el1(const struct kvm_vcpu *vcpu)
@@ -150,7 +150,7 @@ static inline void vcpu_write_elr_el1(const struct kvm_vcpu *vcpu, unsigned long
 
 static __always_inline unsigned long *vcpu_cpsr(const struct kvm_vcpu *vcpu)
 {
-	return (unsigned long *)&vcpu_gp_regs(vcpu)->regs.pstate;
+	return (unsigned long *)&vcpu_gp_regs(vcpu)->pstate;
 }
 
 static __always_inline bool vcpu_mode_is_32bit(const struct kvm_vcpu *vcpu)
@@ -179,14 +179,14 @@ static inline void vcpu_set_thumb(struct kvm_vcpu *vcpu)
 static __always_inline unsigned long vcpu_get_reg(const struct kvm_vcpu *vcpu,
 					 u8 reg_num)
 {
-	return (reg_num == 31) ? 0 : vcpu_gp_regs(vcpu)->regs.regs[reg_num];
+	return (reg_num == 31) ? 0 : vcpu_gp_regs(vcpu)->regs[reg_num];
 }
 
 static __always_inline void vcpu_set_reg(struct kvm_vcpu *vcpu, u8 reg_num,
 				unsigned long val)
 {
 	if (reg_num != 31)
-		vcpu_gp_regs(vcpu)->regs.regs[reg_num] = val;
+		vcpu_gp_regs(vcpu)->regs[reg_num] = val;
 }
 
 static inline unsigned long vcpu_read_spsr(const struct kvm_vcpu *vcpu)
@@ -197,7 +197,7 @@ 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_gp_regs(vcpu)->spsr[KVM_SPSR_EL1];
+		return vcpu->arch.ctxt.spsr[KVM_SPSR_EL1];
 }
 
 static inline void vcpu_write_spsr(struct kvm_vcpu *vcpu, unsigned long v)
@@ -210,7 +210,7 @@ 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_gp_regs(vcpu)->spsr[KVM_SPSR_EL1] = v;
+		vcpu->arch.ctxt.spsr[KVM_SPSR_EL1] = v;
 }
 
 /*
@@ -519,11 +519,11 @@ static __always_inline void kvm_skip_instr(struct kvm_vcpu *vcpu, bool is_wide_i
 static __always_inline void __kvm_skip_instr(struct kvm_vcpu *vcpu)
 {
 	*vcpu_pc(vcpu) = read_sysreg_el2(SYS_ELR);
-	vcpu->arch.ctxt.gp_regs.regs.pstate = read_sysreg_el2(SYS_SPSR);
+	vcpu_gp_regs(vcpu)->pstate = read_sysreg_el2(SYS_SPSR);
 
 	kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
 
-	write_sysreg_el2(vcpu->arch.ctxt.gp_regs.regs.pstate, SYS_SPSR);
+	write_sysreg_el2(vcpu_gp_regs(vcpu)->pstate, SYS_SPSR);
 	write_sysreg_el2(*vcpu_pc(vcpu), SYS_ELR);
 }
 
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index d9360f91ef44..bc1e91573d00 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -236,7 +236,15 @@ enum vcpu_sysreg {
 #define NR_COPRO_REGS	(NR_SYS_REGS * 2)
 
 struct kvm_cpu_context {
-	struct kvm_regs	gp_regs;
+	struct user_pt_regs regs;	/* sp = sp_el0 */
+
+	u64	sp_el1;
+	u64	elr_el1;
+
+	u64	spsr[KVM_NR_SPSR];
+
+	struct user_fpsimd_state fp_regs;
+
 	union {
 		u64 sys_regs[NR_SYS_REGS];
 		u32 copro[NR_COPRO_REGS];
@@ -402,7 +410,7 @@ struct kvm_vcpu_arch {
 				  system_supports_generic_auth()) && \
 				 ((vcpu)->arch.flags & KVM_ARM64_GUEST_HAS_PTRAUTH))
 
-#define vcpu_gp_regs(v)		(&(v)->arch.ctxt.gp_regs)
+#define vcpu_gp_regs(v)		(&(v)->arch.ctxt.regs)
 
 /*
  * Only use __vcpu_sys_reg/ctxt_sys_reg if you know you want the