Linux-libre 4.4-gnupck-4.4-gnu

8 files changed, 102 insertions, 78 deletions

diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
index 5c7e920e4..a5272c07d 100644
--- a/arch/arm64/kvm/Kconfig
+++ b/arch/arm64/kvm/Kconfig
@@ -16,9 +16,13 @@ menuconfig VIRTUALIZATION
 
 if VIRTUALIZATION
 
+config KVM_ARM_VGIC_V3
+	bool
+
 config KVM
 	bool "Kernel-based Virtual Machine (KVM) support"
 	depends on OF
+	depends on !ARM64_16K_PAGES
 	select MMU_NOTIFIER
 	select PREEMPT_NOTIFIERS
 	select ANON_INODES
@@ -31,8 +35,11 @@ config KVM
 	select KVM_VFIO
 	select HAVE_KVM_EVENTFD
 	select HAVE_KVM_IRQFD
+	select KVM_ARM_VGIC_V3
 	---help---
 	  Support hosting virtualized guest machines.
+	  We don't support KVM with 16K page tables yet, due to the multiple
+	  levels of fake page tables.
 
 	  If unsure, say N.
 
@@ -41,4 +48,6 @@ config KVM_ARM_HOST
 	---help---
 	  Provides host support for ARM processors.
 
+source drivers/vhost/Kconfig
+
 endif # VIRTUALIZATION
diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c
index 68a0759b1..15f0477b0 100644
--- a/arch/arm64/kvm/handle_exit.c
+++ b/arch/arm64/kvm/handle_exit.c
@@ -37,7 +37,7 @@ static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run)
 {
 	int ret;
 
-	trace_kvm_hvc_arm64(*vcpu_pc(vcpu), *vcpu_reg(vcpu, 0),
+	trace_kvm_hvc_arm64(*vcpu_pc(vcpu), vcpu_get_reg(vcpu, 0),
 			    kvm_vcpu_hvc_get_imm(vcpu));
 
 	ret = kvm_psci_call(vcpu);
diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S
index e5836138e..86c289832 100644
--- a/arch/arm64/kvm/hyp.S
+++ b/arch/arm64/kvm/hyp.S
@@ -864,6 +864,10 @@ ENTRY(__kvm_flush_vm_context)
 ENDPROC(__kvm_flush_vm_context)
 
 __kvm_hyp_panic:
+	// Stash PAR_EL1 before corrupting it in __restore_sysregs
+	mrs	x0, par_el1
+	push	x0, xzr
+
 	// Guess the context by looking at VTTBR:
 	// If zero, then we're already a host.
 	// Otherwise restore a minimal host context before panicing.
@@ -880,6 +884,14 @@ __kvm_hyp_panic:
 
 	bl __restore_sysregs
 
+	/*
+	 * Make sure we have a valid host stack, and don't leave junk in the
+	 * frame pointer that will give us a misleading host stack unwinding.
+	 */
+	ldr	x22, [x2, #CPU_GP_REG_OFFSET(CPU_SP_EL1)]
+	msr	sp_el1, x22
+	mov	x29, xzr
+
 1:	adr	x0, __hyp_panic_str
 	adr	x1, 2f
 	ldp	x2, x3, [x1]
@@ -890,7 +902,7 @@ __kvm_hyp_panic:
 	mrs	x3, esr_el2
 	mrs	x4, far_el2
 	mrs	x5, hpfar_el2
-	mrs	x6, par_el1
+	pop	x6, xzr		// active context PAR_EL1
 	mrs	x7, tpidr_el2
 
 	mov	lr, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT |\
@@ -906,7 +918,7 @@ __kvm_hyp_panic:
 ENDPROC(__kvm_hyp_panic)
 
 __hyp_panic_str:
-	.ascii	"HYP panic:\nPS:%08x PC:%p ESR:%p\nFAR:%p HPFAR:%p PAR:%p\nVCPU:%p\n\0"
+	.ascii	"HYP panic:\nPS:%08x PC:%016x ESR:%08x\nFAR:%016x HPFAR:%016x PAR:%016x\nVCPU:%p\n\0"
 
 	.align	2
 
@@ -1007,9 +1019,15 @@ el1_trap:
 	b.ne	1f		// Not an abort we care about
 
 	/* This is an abort. Check for permission fault */
+alternative_if_not ARM64_WORKAROUND_834220
 	and	x2, x1, #ESR_ELx_FSC_TYPE
 	cmp	x2, #FSC_PERM
 	b.ne	1f		// Not a permission fault
+alternative_else
+	nop			// Use the permission fault path to
+	nop			// check for a valid S1 translation,
+	nop			// regardless of the ESR value.
+alternative_endif
 
 	/*
 	 * Check for Stage-1 page table walk, which is guaranteed
diff --git a/arch/arm64/kvm/inject_fault.c b/arch/arm64/kvm/inject_fault.c
index 85c57158d..648112e90 100644
--- a/arch/arm64/kvm/inject_fault.c
+++ b/arch/arm64/kvm/inject_fault.c
@@ -48,7 +48,7 @@ static void prepare_fault32(struct kvm_vcpu *vcpu, u32 mode, u32 vect_offset)
 
 	/* Note: These now point to the banked copies */
 	*vcpu_spsr(vcpu) = new_spsr_value;
-	*vcpu_reg(vcpu, 14) = *vcpu_pc(vcpu) + return_offset;
+	*vcpu_reg32(vcpu, 14) = *vcpu_pc(vcpu) + return_offset;
 
 	/* Branch to exception vector */
 	if (sctlr & (1 << 13))
diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
index 91cf5350b..f34745cb3 100644
--- a/arch/arm64/kvm/reset.c
+++ b/arch/arm64/kvm/reset.c
@@ -53,7 +53,7 @@ static bool cpu_has_32bit_el1(void)
 {
 	u64 pfr0;
 
-	pfr0 = read_cpuid(ID_AA64PFR0_EL1);
+	pfr0 = read_system_reg(SYS_ID_AA64PFR0_EL1);
 	return !!(pfr0 & 0x20);
 }
 
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index d03d3af17..d2650e84f 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -78,7 +78,7 @@ static u32 get_ccsidr(u32 csselr)
  * See note at ARMv7 ARM B1.14.4 (TL;DR: S/W ops are not easily virtualized).
  */
 static bool access_dcsw(struct kvm_vcpu *vcpu,
-			const struct sys_reg_params *p,
+			struct sys_reg_params *p,
 			const struct sys_reg_desc *r)
 {
 	if (!p->is_write)
@@ -94,21 +94,19 @@ static bool access_dcsw(struct kvm_vcpu *vcpu,
  * sys_regs and leave it in complete control of the caches.
  */
 static bool access_vm_reg(struct kvm_vcpu *vcpu,
-			  const struct sys_reg_params *p,
+			  struct sys_reg_params *p,
 			  const struct sys_reg_desc *r)
 {
-	unsigned long val;
 	bool was_enabled = vcpu_has_cache_enabled(vcpu);
 
 	BUG_ON(!p->is_write);
 
-	val = *vcpu_reg(vcpu, p->Rt);
 	if (!p->is_aarch32) {
-		vcpu_sys_reg(vcpu, r->reg) = val;
+		vcpu_sys_reg(vcpu, r->reg) = p->regval;
 	} else {
 		if (!p->is_32bit)
-			vcpu_cp15_64_high(vcpu, r->reg) = val >> 32;
-		vcpu_cp15_64_low(vcpu, r->reg) = val & 0xffffffffUL;
+			vcpu_cp15_64_high(vcpu, r->reg) = upper_32_bits(p->regval);
+		vcpu_cp15_64_low(vcpu, r->reg) = lower_32_bits(p->regval);
 	}
 
 	kvm_toggle_cache(vcpu, was_enabled);
@@ -122,22 +120,19 @@ static bool access_vm_reg(struct kvm_vcpu *vcpu,
  * for both AArch64 and AArch32 accesses.
  */
 static bool access_gic_sgi(struct kvm_vcpu *vcpu,
-			   const struct sys_reg_params *p,
+			   struct sys_reg_params *p,
 			   const struct sys_reg_desc *r)
 {
-	u64 val;
-
 	if (!p->is_write)
 		return read_from_write_only(vcpu, p);
 
-	val = *vcpu_reg(vcpu, p->Rt);
-	vgic_v3_dispatch_sgi(vcpu, val);
+	vgic_v3_dispatch_sgi(vcpu, p->regval);
 
 	return true;
 }
 
 static bool trap_raz_wi(struct kvm_vcpu *vcpu,
-			const struct sys_reg_params *p,
+			struct sys_reg_params *p,
 			const struct sys_reg_desc *r)
 {
 	if (p->is_write)
@@ -147,19 +142,19 @@ static bool trap_raz_wi(struct kvm_vcpu *vcpu,
 }
 
 static bool trap_oslsr_el1(struct kvm_vcpu *vcpu,
-			   const struct sys_reg_params *p,
+			   struct sys_reg_params *p,
 			   const struct sys_reg_desc *r)
 {
 	if (p->is_write) {
 		return ignore_write(vcpu, p);
 	} else {
-		*vcpu_reg(vcpu, p->Rt) = (1 << 3);
+		p->regval = (1 << 3);
 		return true;
 	}
 }
 
 static bool trap_dbgauthstatus_el1(struct kvm_vcpu *vcpu,
-				   const struct sys_reg_params *p,
+				   struct sys_reg_params *p,
 				   const struct sys_reg_desc *r)
 {
 	if (p->is_write) {
@@ -167,7 +162,7 @@ static bool trap_dbgauthstatus_el1(struct kvm_vcpu *vcpu,
 	} else {
 		u32 val;
 		asm volatile("mrs %0, dbgauthstatus_el1" : "=r" (val));
-		*vcpu_reg(vcpu, p->Rt) = val;
+		p->regval = val;
 		return true;
 	}
 }
@@ -200,17 +195,17 @@ static bool trap_dbgauthstatus_el1(struct kvm_vcpu *vcpu,
  *   now use the debug registers.
  */
 static bool trap_debug_regs(struct kvm_vcpu *vcpu,
-			    const struct sys_reg_params *p,
+			    struct sys_reg_params *p,
 			    const struct sys_reg_desc *r)
 {
 	if (p->is_write) {
-		vcpu_sys_reg(vcpu, r->reg) = *vcpu_reg(vcpu, p->Rt);
+		vcpu_sys_reg(vcpu, r->reg) = p->regval;
 		vcpu->arch.debug_flags |= KVM_ARM64_DEBUG_DIRTY;
 	} else {
-		*vcpu_reg(vcpu, p->Rt) = vcpu_sys_reg(vcpu, r->reg);
+		p->regval = vcpu_sys_reg(vcpu, r->reg);
 	}
 
-	trace_trap_reg(__func__, r->reg, p->is_write, *vcpu_reg(vcpu, p->Rt));
+	trace_trap_reg(__func__, r->reg, p->is_write, p->regval);
 
 	return true;
 }
@@ -225,10 +220,10 @@ static bool trap_debug_regs(struct kvm_vcpu *vcpu,
  * hyp.S code switches between host and guest values in future.
  */
 static inline void reg_to_dbg(struct kvm_vcpu *vcpu,
-			      const struct sys_reg_params *p,
+			      struct sys_reg_params *p,
 			      u64 *dbg_reg)
 {
-	u64 val = *vcpu_reg(vcpu, p->Rt);
+	u64 val = p->regval;
 
 	if (p->is_32bit) {
 		val &= 0xffffffffUL;
@@ -240,19 +235,16 @@ static inline void reg_to_dbg(struct kvm_vcpu *vcpu,
 }
 
 static inline void dbg_to_reg(struct kvm_vcpu *vcpu,
-			      const struct sys_reg_params *p,
+			      struct sys_reg_params *p,
 			      u64 *dbg_reg)
 {
-	u64 val = *dbg_reg;
-
+	p->regval = *dbg_reg;
 	if (p->is_32bit)
-		val &= 0xffffffffUL;
-
-	*vcpu_reg(vcpu, p->Rt) = val;
+		p->regval &= 0xffffffffUL;
 }
 
 static inline bool trap_bvr(struct kvm_vcpu *vcpu,
-			    const struct sys_reg_params *p,
+			    struct sys_reg_params *p,
 			    const struct sys_reg_desc *rd)
 {
 	u64 *dbg_reg = &vcpu->arch.vcpu_debug_state.dbg_bvr[rd->reg];
@@ -294,7 +286,7 @@ static inline void reset_bvr(struct kvm_vcpu *vcpu,
 }
 
 static inline bool trap_bcr(struct kvm_vcpu *vcpu,
-			    const struct sys_reg_params *p,
+			    struct sys_reg_params *p,
 			    const struct sys_reg_desc *rd)
 {
 	u64 *dbg_reg = &vcpu->arch.vcpu_debug_state.dbg_bcr[rd->reg];
@@ -337,7 +329,7 @@ static inline void reset_bcr(struct kvm_vcpu *vcpu,
 }
 
 static inline bool trap_wvr(struct kvm_vcpu *vcpu,
-			    const struct sys_reg_params *p,
+			    struct sys_reg_params *p,
 			    const struct sys_reg_desc *rd)
 {
 	u64 *dbg_reg = &vcpu->arch.vcpu_debug_state.dbg_wvr[rd->reg];
@@ -380,7 +372,7 @@ static inline void reset_wvr(struct kvm_vcpu *vcpu,
 }
 
 static inline bool trap_wcr(struct kvm_vcpu *vcpu,
-			    const struct sys_reg_params *p,
+			    struct sys_reg_params *p,
 			    const struct sys_reg_desc *rd)
 {
 	u64 *dbg_reg = &vcpu->arch.vcpu_debug_state.dbg_wcr[rd->reg];
@@ -687,33 +679,33 @@ static const struct sys_reg_desc sys_reg_descs[] = {
 };
 
 static bool trap_dbgidr(struct kvm_vcpu *vcpu,
-			const struct sys_reg_params *p,
+			struct sys_reg_params *p,
 			const struct sys_reg_desc *r)
 {
 	if (p->is_write) {
 		return ignore_write(vcpu, p);
 	} else {
-		u64 dfr = read_cpuid(ID_AA64DFR0_EL1);
-		u64 pfr = read_cpuid(ID_AA64PFR0_EL1);
-		u32 el3 = !!((pfr >> 12) & 0xf);
-
-		*vcpu_reg(vcpu, p->Rt) = ((((dfr >> 20) & 0xf) << 28) |
-					  (((dfr >> 12) & 0xf) << 24) |
-					  (((dfr >> 28) & 0xf) << 20) |
-					  (6 << 16) | (el3 << 14) | (el3 << 12));
+		u64 dfr = read_system_reg(SYS_ID_AA64DFR0_EL1);
+		u64 pfr = read_system_reg(SYS_ID_AA64PFR0_EL1);
+		u32 el3 = !!cpuid_feature_extract_field(pfr, ID_AA64PFR0_EL3_SHIFT);
+
+		p->regval = ((((dfr >> ID_AA64DFR0_WRPS_SHIFT) & 0xf) << 28) |
+			     (((dfr >> ID_AA64DFR0_BRPS_SHIFT) & 0xf) << 24) |
+			     (((dfr >> ID_AA64DFR0_CTX_CMPS_SHIFT) & 0xf) << 20)
+			     | (6 << 16) | (el3 << 14) | (el3 << 12));
 		return true;
 	}
 }
 
 static bool trap_debug32(struct kvm_vcpu *vcpu,
-			 const struct sys_reg_params *p,
+			 struct sys_reg_params *p,
 			 const struct sys_reg_desc *r)
 {
 	if (p->is_write) {
-		vcpu_cp14(vcpu, r->reg) = *vcpu_reg(vcpu, p->Rt);
+		vcpu_cp14(vcpu, r->reg) = p->regval;
 		vcpu->arch.debug_flags |= KVM_ARM64_DEBUG_DIRTY;
 	} else {
-		*vcpu_reg(vcpu, p->Rt) = vcpu_cp14(vcpu, r->reg);
+		p->regval = vcpu_cp14(vcpu, r->reg);
 	}
 
 	return true;
@@ -731,7 +723,7 @@ static bool trap_debug32(struct kvm_vcpu *vcpu,
  */
 
 static inline bool trap_xvr(struct kvm_vcpu *vcpu,
-			    const struct sys_reg_params *p,
+			    struct sys_reg_params *p,
 			    const struct sys_reg_desc *rd)
 {
 	u64 *dbg_reg = &vcpu->arch.vcpu_debug_state.dbg_bvr[rd->reg];
@@ -740,12 +732,12 @@ static inline bool trap_xvr(struct kvm_vcpu *vcpu,
 		u64 val = *dbg_reg;
 
 		val &= 0xffffffffUL;
-		val |= *vcpu_reg(vcpu, p->Rt) << 32;
+		val |= p->regval << 32;
 		*dbg_reg = val;
 
 		vcpu->arch.debug_flags |= KVM_ARM64_DEBUG_DIRTY;
 	} else {
-		*vcpu_reg(vcpu, p->Rt) = *dbg_reg >> 32;
+		p->regval = *dbg_reg >> 32;
 	}
 
 	trace_trap_reg(__func__, rd->reg, p->is_write, *dbg_reg);
@@ -991,7 +983,7 @@ int kvm_handle_cp14_load_store(struct kvm_vcpu *vcpu, struct kvm_run *run)
  * Return 0 if the access has been handled, and -1 if not.
  */
 static int emulate_cp(struct kvm_vcpu *vcpu,
-		      const struct sys_reg_params *params,
+		      struct sys_reg_params *params,
 		      const struct sys_reg_desc *table,
 		      size_t num)
 {
@@ -1062,12 +1054,12 @@ static int kvm_handle_cp_64(struct kvm_vcpu *vcpu,
 {
 	struct sys_reg_params params;
 	u32 hsr = kvm_vcpu_get_hsr(vcpu);
+	int Rt = (hsr >> 5) & 0xf;
 	int Rt2 = (hsr >> 10) & 0xf;
 
 	params.is_aarch32 = true;
 	params.is_32bit = false;
 	params.CRm = (hsr >> 1) & 0xf;
-	params.Rt = (hsr >> 5) & 0xf;
 	params.is_write = ((hsr & 1) == 0);
 
 	params.Op0 = 0;
@@ -1076,15 +1068,12 @@ static int kvm_handle_cp_64(struct kvm_vcpu *vcpu,
 	params.CRn = 0;
 
 	/*
-	 * Massive hack here. Store Rt2 in the top 32bits so we only
-	 * have one register to deal with. As we use the same trap
+	 * Make a 64-bit value out of Rt and Rt2. As we use the same trap
 	 * backends between AArch32 and AArch64, we get away with it.
 	 */
 	if (params.is_write) {
-		u64 val = *vcpu_reg(vcpu, params.Rt);
-		val &= 0xffffffff;
-		val |= *vcpu_reg(vcpu, Rt2) << 32;
-		*vcpu_reg(vcpu, params.Rt) = val;
+		params.regval = vcpu_get_reg(vcpu, Rt) & 0xffffffff;
+		params.regval |= vcpu_get_reg(vcpu, Rt2) << 32;
 	}
 
 	if (!emulate_cp(vcpu, &params, target_specific, nr_specific))
@@ -1095,11 +1084,10 @@ static int kvm_handle_cp_64(struct kvm_vcpu *vcpu,
 	unhandled_cp_access(vcpu, &params);
 
 out:
-	/* Do the opposite hack for the read side */
+	/* Split up the value between registers for the read side */
 	if (!params.is_write) {
-		u64 val = *vcpu_reg(vcpu, params.Rt);
-		val >>= 32;
-		*vcpu_reg(vcpu, Rt2) = val;
+		vcpu_set_reg(vcpu, Rt, lower_32_bits(params.regval));
+		vcpu_set_reg(vcpu, Rt2, upper_32_bits(params.regval));
 	}
 
 	return 1;
@@ -1118,21 +1106,24 @@ static int kvm_handle_cp_32(struct kvm_vcpu *vcpu,
 {
 	struct sys_reg_params params;
 	u32 hsr = kvm_vcpu_get_hsr(vcpu);
+	int Rt  = (hsr >> 5) & 0xf;
 
 	params.is_aarch32 = true;
 	params.is_32bit = true;
 	params.CRm = (hsr >> 1) & 0xf;
-	params.Rt  = (hsr >> 5) & 0xf;
+	params.regval = vcpu_get_reg(vcpu, Rt);
 	params.is_write = ((hsr & 1) == 0);
 	params.CRn = (hsr >> 10) & 0xf;
 	params.Op0 = 0;
 	params.Op1 = (hsr >> 14) & 0x7;
 	params.Op2 = (hsr >> 17) & 0x7;
 
-	if (!emulate_cp(vcpu, &params, target_specific, nr_specific))
-		return 1;
-	if (!emulate_cp(vcpu, &params, global, nr_global))
+	if (!emulate_cp(vcpu, &params, target_specific, nr_specific) ||
+	    !emulate_cp(vcpu, &params, global, nr_global)) {
+		if (!params.is_write)
+			vcpu_set_reg(vcpu, Rt, params.regval);
 		return 1;
+	}
 
 	unhandled_cp_access(vcpu, &params);
 	return 1;
@@ -1175,7 +1166,7 @@ int kvm_handle_cp14_32(struct kvm_vcpu *vcpu, struct kvm_run *run)
 }
 
 static int emulate_sys_reg(struct kvm_vcpu *vcpu,
-			   const struct sys_reg_params *params)
+			   struct sys_reg_params *params)
 {
 	size_t num;
 	const struct sys_reg_desc *table, *r;
@@ -1230,6 +1221,8 @@ int kvm_handle_sys_reg(struct kvm_vcpu *vcpu, struct kvm_run *run)
 {
 	struct sys_reg_params params;
 	unsigned long esr = kvm_vcpu_get_hsr(vcpu);
+	int Rt = (esr >> 5) & 0x1f;
+	int ret;
 
 	trace_kvm_handle_sys_reg(esr);
 
@@ -1240,10 +1233,14 @@ int kvm_handle_sys_reg(struct kvm_vcpu *vcpu, struct kvm_run *run)
 	params.CRn = (esr >> 10) & 0xf;
 	params.CRm = (esr >> 1) & 0xf;
 	params.Op2 = (esr >> 17) & 0x7;
-	params.Rt = (esr >> 5) & 0x1f;
+	params.regval = vcpu_get_reg(vcpu, Rt);
 	params.is_write = !(esr & 1);
 
-	return emulate_sys_reg(vcpu, &params);
+	ret = emulate_sys_reg(vcpu, &params);
+
+	if (!params.is_write)
+		vcpu_set_reg(vcpu, Rt, params.regval);
+	return ret;
 }
 
 /******************************************************************************
diff --git a/arch/arm64/kvm/sys_regs.h b/arch/arm64/kvm/sys_regs.h
index eaa324e4d..dbbb01cfb 100644
--- a/arch/arm64/kvm/sys_regs.h
+++ b/arch/arm64/kvm/sys_regs.h
@@ -28,7 +28,7 @@ struct sys_reg_params {
 	u8	CRn;
 	u8	CRm;
 	u8	Op2;
-	u8	Rt;
+	u64	regval;
 	bool	is_write;
 	bool	is_aarch32;
 	bool	is_32bit;	/* Only valid if is_aarch32 is true */
@@ -44,7 +44,7 @@ struct sys_reg_desc {
 
 	/* Trapped access from guest, if non-NULL. */
 	bool (*access)(struct kvm_vcpu *,
-		       const struct sys_reg_params *,
+		       struct sys_reg_params *,
 		       const struct sys_reg_desc *);
 
 	/* Initialization for vcpu. */
@@ -77,9 +77,9 @@ static inline bool ignore_write(struct kvm_vcpu *vcpu,
 }
 
 static inline bool read_zero(struct kvm_vcpu *vcpu,
-			     const struct sys_reg_params *p)
+			     struct sys_reg_params *p)
 {
-	*vcpu_reg(vcpu, p->Rt) = 0;
+	p->regval = 0;
 	return true;
 }
 
diff --git a/arch/arm64/kvm/sys_regs_generic_v8.c b/arch/arm64/kvm/sys_regs_generic_v8.c
index 1e4576824..ed90578fa 100644
--- a/arch/arm64/kvm/sys_regs_generic_v8.c
+++ b/arch/arm64/kvm/sys_regs_generic_v8.c
@@ -31,13 +31,13 @@
 #include "sys_regs.h"
 
 static bool access_actlr(struct kvm_vcpu *vcpu,
-			 const struct sys_reg_params *p,
+			 struct sys_reg_params *p,
 			 const struct sys_reg_desc *r)
 {
 	if (p->is_write)
 		return ignore_write(vcpu, p);
 
-	*vcpu_reg(vcpu, p->Rt) = vcpu_sys_reg(vcpu, ACTLR_EL1);
+	p->regval = vcpu_sys_reg(vcpu, ACTLR_EL1);
 	return true;
 }