Merge tag 'kvm-ppc-next-5.9-1' of...

Merge tag 'kvm-ppc-next-5.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into kvm-next-5.6

PPC KVM update for 5.9

- Improvements and bug-fixes for secure VM support, giving reduced startup
  time and memory hotplug support.
- Locking fixes in nested KVM code
- Increase number of guests supported by HV KVM to 4094
- Preliminary POWER10 support

Documentation/powerpc/ultravisor.rst

@@ -895,6 +895,7 @@ Return values
     One of the following values:
 
 	* H_SUCCESS	 on success.
+        * H_STATE        if the VM is not in a position to switch to secure.
 
 Description
 ~~~~~~~~~~~
@@ -933,6 +934,8 @@ Return values
 	* H_UNSUPPORTED		if called from the wrong context (e.g.
 				from an SVM or before an H_SVM_INIT_START
 				hypercall).
+	* H_STATE		if the hypervisor could not successfully
+                                transition the VM to Secure VM.
 
 Description
 ~~~~~~~~~~~

arch/powerpc/include/asm/kvm_book3s_uvmem.h

@@ -23,6 +23,10 @@ int kvmppc_send_page_to_uv(struct kvm *kvm, unsigned long gfn);
 unsigned long kvmppc_h_svm_init_abort(struct kvm *kvm);
 void kvmppc_uvmem_drop_pages(const struct kvm_memory_slot *free,
 			     struct kvm *kvm, bool skip_page_out);
+int kvmppc_uvmem_memslot_create(struct kvm *kvm,
+		const struct kvm_memory_slot *new);
+void kvmppc_uvmem_memslot_delete(struct kvm *kvm,
+		const struct kvm_memory_slot *old);
 #else
 static inline int kvmppc_uvmem_init(void)
 {
@@ -82,5 +86,15 @@ static inline int kvmppc_send_page_to_uv(struct kvm *kvm, unsigned long gfn)
 static inline void
 kvmppc_uvmem_drop_pages(const struct kvm_memory_slot *free,
 			struct kvm *kvm, bool skip_page_out) { }
+
+static inline int  kvmppc_uvmem_memslot_create(struct kvm *kvm,
+		const struct kvm_memory_slot *new)
+{
+	return H_UNSUPPORTED;
+}
+
+static inline void  kvmppc_uvmem_memslot_delete(struct kvm *kvm,
+		const struct kvm_memory_slot *old) { }
+
 #endif /* CONFIG_PPC_UV */
 #endif /* __ASM_KVM_BOOK3S_UVMEM_H__ */

arch/powerpc/include/asm/kvm_ppc.h

@@ -59,7 +59,7 @@ enum xlate_readwrite {
 };
 
 extern int kvmppc_vcpu_run(struct kvm_vcpu *vcpu);
-extern int __kvmppc_vcpu_run(struct kvm_run *run, struct kvm_vcpu *vcpu);
+extern int __kvmppc_vcpu_run(struct kvm_vcpu *vcpu);
 extern void kvmppc_handler_highmem(void);
 
 extern void kvmppc_dump_vcpu(struct kvm_vcpu *vcpu);

arch/powerpc/include/asm/reg.h

@@ -474,7 +474,8 @@
 #ifndef SPRN_LPID
 #define SPRN_LPID	0x13F	/* Logical Partition Identifier */
 #endif
-#define   LPID_RSVD	0x3ff		/* Reserved LPID for partn switching */
+#define   LPID_RSVD_POWER7	0x3ff	/* Reserved LPID for partn switching */
+#define   LPID_RSVD		0xfff	/* Reserved LPID for partn switching */
 #define	SPRN_HMER	0x150	/* Hypervisor maintenance exception reg */
 #define   HMER_DEBUG_TRIG	(1ul << (63 - 17)) /* Debug trigger */
 #define	SPRN_HMEER	0x151	/* Hyp maintenance exception enable reg */
@@ -1362,6 +1363,7 @@
 #define PVR_ARCH_206p	0x0f100003
 #define PVR_ARCH_207	0x0f000004
 #define PVR_ARCH_300	0x0f000005
+#define PVR_ARCH_31	0x0f000006
 
 /* Macros for setting and retrieving special purpose registers */
 #ifndef __ASSEMBLY__

arch/powerpc/kvm/book3s_64_mmu_hv.c

@@ -260,11 +260,15 @@ int kvmppc_mmu_hv_init(void)
 	if (!mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE))
 		return -EINVAL;
 
-	/* POWER7 has 10-bit LPIDs (12-bit in POWER8) */
 	host_lpid = 0;
 	if (cpu_has_feature(CPU_FTR_HVMODE))
 		host_lpid = mfspr(SPRN_LPID);
+
+	/* POWER8 and above have 12-bit LPIDs (10-bit in POWER7) */
+	if (cpu_has_feature(CPU_FTR_ARCH_207S))
 		rsvd_lpid = LPID_RSVD;
+	else
+		rsvd_lpid = LPID_RSVD_POWER7;
 
 	kvmppc_init_lpid(rsvd_lpid + 1);
 

arch/powerpc/kvm/book3s_64_mmu_radix.c

@@ -161,7 +161,9 @@ int kvmppc_mmu_walk_radix_tree(struct kvm_vcpu *vcpu, gva_t eaddr,
 			return -EINVAL;
 		/* Read the entry from guest memory */
 		addr = base + (index * sizeof(rpte));
+		vcpu->srcu_idx = srcu_read_lock(&kvm->srcu);
 		ret = kvm_read_guest(kvm, addr, &rpte, sizeof(rpte));
+		srcu_read_unlock(&kvm->srcu, vcpu->srcu_idx);
 		if (ret) {
 			if (pte_ret_p)
 				*pte_ret_p = addr;
@@ -237,7 +239,9 @@ int kvmppc_mmu_radix_translate_table(struct kvm_vcpu *vcpu, gva_t eaddr,
 
 	/* Read the table to find the root of the radix tree */
 	ptbl = (table & PRTB_MASK) + (table_index * sizeof(entry));
+	vcpu->srcu_idx = srcu_read_lock(&kvm->srcu);
 	ret = kvm_read_guest(kvm, ptbl, &entry, sizeof(entry));
+	srcu_read_unlock(&kvm->srcu, vcpu->srcu_idx);
 	if (ret)
 		return ret;
 

arch/powerpc/kvm/book3s_hv.c

@@ -343,13 +343,18 @@ static void kvmppc_set_pvr_hv(struct kvm_vcpu *vcpu, u32 pvr)
 	vcpu->arch.pvr = pvr;
 }
 
+/* Dummy value used in computing PCR value below */
+#define PCR_ARCH_31    (PCR_ARCH_300 << 1)
+
 static int kvmppc_set_arch_compat(struct kvm_vcpu *vcpu, u32 arch_compat)
 {
 	unsigned long host_pcr_bit = 0, guest_pcr_bit = 0;
 	struct kvmppc_vcore *vc = vcpu->arch.vcore;
 
 	/* We can (emulate) our own architecture version and anything older */
-	if (cpu_has_feature(CPU_FTR_ARCH_300))
+	if (cpu_has_feature(CPU_FTR_ARCH_31))
+		host_pcr_bit = PCR_ARCH_31;
+	else if (cpu_has_feature(CPU_FTR_ARCH_300))
 		host_pcr_bit = PCR_ARCH_300;
 	else if (cpu_has_feature(CPU_FTR_ARCH_207S))
 		host_pcr_bit = PCR_ARCH_207;
@@ -375,6 +380,9 @@ static int kvmppc_set_arch_compat(struct kvm_vcpu *vcpu, u32 arch_compat)
 		case PVR_ARCH_300:
 			guest_pcr_bit = PCR_ARCH_300;
 			break;
+		case PVR_ARCH_31:
+			guest_pcr_bit = PCR_ARCH_31;
+			break;
 		default:
 			return -EINVAL;
 		}
@@ -2355,7 +2363,7 @@ static int kvmppc_core_vcpu_create_hv(struct kvm_vcpu *vcpu)
 	 * to trap and then we emulate them.
 	 */
 	vcpu->arch.hfscr = HFSCR_TAR | HFSCR_EBB | HFSCR_PM | HFSCR_BHRB |
-		HFSCR_DSCR | HFSCR_VECVSX | HFSCR_FP;
+		HFSCR_DSCR | HFSCR_VECVSX | HFSCR_FP | HFSCR_PREFIX;
 	if (cpu_has_feature(CPU_FTR_HVMODE)) {
 		vcpu->arch.hfscr &= mfspr(SPRN_HFSCR);
 		if (cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST))
@@ -4552,16 +4560,14 @@ static void kvmppc_core_commit_memory_region_hv(struct kvm *kvm,
 
 	switch (change) {
 	case KVM_MR_CREATE:
-		if (kvmppc_uvmem_slot_init(kvm, new))
-			return;
-		uv_register_mem_slot(kvm->arch.lpid,
-				     new->base_gfn << PAGE_SHIFT,
-				     new->npages * PAGE_SIZE,
-				     0, new->id);
+		/*
+		 * @TODO kvmppc_uvmem_memslot_create() can fail and
+		 * return error. Fix this.
+		 */
+		kvmppc_uvmem_memslot_create(kvm, new);
 		break;
 	case KVM_MR_DELETE:
-		uv_unregister_mem_slot(kvm->arch.lpid, old->id);
-		kvmppc_uvmem_slot_free(kvm, old);
+		kvmppc_uvmem_memslot_delete(kvm, old);
 		break;
 	default:
 		/* TODO: Handle KVM_MR_MOVE */

arch/powerpc/kvm/book3s_hv_nested.c

@@ -233,20 +233,21 @@ long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu)
 
 	/* copy parameters in */
 	hv_ptr = kvmppc_get_gpr(vcpu, 4);
+	regs_ptr = kvmppc_get_gpr(vcpu, 5);
+	vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
 	err = kvm_vcpu_read_guest(vcpu, hv_ptr, &l2_hv,
-				  sizeof(struct hv_guest_state));
+				  sizeof(struct hv_guest_state)) ||
+		kvm_vcpu_read_guest(vcpu, regs_ptr, &l2_regs,
+				    sizeof(struct pt_regs));
+	srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
 	if (err)
 		return H_PARAMETER;
+
 	if (kvmppc_need_byteswap(vcpu))
 		byteswap_hv_regs(&l2_hv);
 	if (l2_hv.version != HV_GUEST_STATE_VERSION)
 		return H_P2;
 
-	regs_ptr = kvmppc_get_gpr(vcpu, 5);
-	err = kvm_vcpu_read_guest(vcpu, regs_ptr, &l2_regs,
-				  sizeof(struct pt_regs));
-	if (err)
-		return H_PARAMETER;
 	if (kvmppc_need_byteswap(vcpu))
 		byteswap_pt_regs(&l2_regs);
 	if (l2_hv.vcpu_token >= NR_CPUS)
@@ -323,12 +324,12 @@ long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu)
 		byteswap_hv_regs(&l2_hv);
 		byteswap_pt_regs(&l2_regs);
 	}
+	vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
 	err = kvm_vcpu_write_guest(vcpu, hv_ptr, &l2_hv,
-				   sizeof(struct hv_guest_state));
-	if (err)
-		return H_AUTHORITY;
-	err = kvm_vcpu_write_guest(vcpu, regs_ptr, &l2_regs,
+				   sizeof(struct hv_guest_state)) ||
+		kvm_vcpu_write_guest(vcpu, regs_ptr, &l2_regs,
 				   sizeof(struct pt_regs));
+	srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
 	if (err)
 		return H_AUTHORITY;
 
@@ -508,12 +509,16 @@ long kvmhv_copy_tofrom_guest_nested(struct kvm_vcpu *vcpu)
 			goto not_found;
 
 		/* Write what was loaded into our buffer back to the L1 guest */
+		vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
 		rc = kvm_vcpu_write_guest(vcpu, gp_to, buf, n);
+		srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
 		if (rc)
 			goto not_found;
 	} else {
 		/* Load the data to be stored from the L1 guest into our buf */
+		vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
 		rc = kvm_vcpu_read_guest(vcpu, gp_from, buf, n);
+		srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
 		if (rc)
 			goto not_found;
 
@@ -548,9 +553,12 @@ static void kvmhv_update_ptbl_cache(struct kvm_nested_guest *gp)
 
 	ret = -EFAULT;
 	ptbl_addr = (kvm->arch.l1_ptcr & PRTB_MASK) + (gp->l1_lpid << 4);
-	if (gp->l1_lpid < (1ul << ((kvm->arch.l1_ptcr & PRTS_MASK) + 8)))
+	if (gp->l1_lpid < (1ul << ((kvm->arch.l1_ptcr & PRTS_MASK) + 8))) {
+		int srcu_idx = srcu_read_lock(&kvm->srcu);
 		ret = kvm_read_guest(kvm, ptbl_addr,
 				     &ptbl_entry, sizeof(ptbl_entry));
+		srcu_read_unlock(&kvm->srcu, srcu_idx);
+	}
 	if (ret) {
 		gp->l1_gr_to_hr = 0;
 		gp->process_table = 0;

arch/powerpc/kvm/book3s_interrupts.S

@@ -55,8 +55,7 @@
  ****************************************************************************/
 
 /* Registers:
- *  r3: kvm_run pointer
- *  r4: vcpu pointer
+ *  r3: vcpu pointer
  */
 _GLOBAL(__kvmppc_vcpu_run)
 
@@ -68,8 +67,8 @@ kvm_start_entry:
 	/* Save host state to the stack */
 	PPC_STLU r1, -SWITCH_FRAME_SIZE(r1)
 
-	/* Save r3 (kvm_run) and r4 (vcpu) */
-	SAVE_2GPRS(3, r1)
+	/* Save r3 (vcpu) */
+	SAVE_GPR(3, r1)
 
 	/* Save non-volatile registers (r14 - r31) */
 	SAVE_NVGPRS(r1)
@@ -82,47 +81,46 @@ kvm_start_entry:
 	PPC_STL	r0, _LINK(r1)
 
 	/* Load non-volatile guest state from the vcpu */
-	VCPU_LOAD_NVGPRS(r4)
+	VCPU_LOAD_NVGPRS(r3)
 
 kvm_start_lightweight:
 	/* Copy registers into shadow vcpu so we can access them in real mode */
-	mr	r3, r4
 	bl	FUNC(kvmppc_copy_to_svcpu)
 	nop
-	REST_GPR(4, r1)
+	REST_GPR(3, r1)
 
 #ifdef CONFIG_PPC_BOOK3S_64
 	/* Get the dcbz32 flag */
-	PPC_LL	r3, VCPU_HFLAGS(r4)
-	rldicl	r3, r3, 0, 63		/* r3 &= 1 */
-	stb	r3, HSTATE_RESTORE_HID5(r13)
+	PPC_LL	r0, VCPU_HFLAGS(r3)
+	rldicl	r0, r0, 0, 63		/* r3 &= 1 */
+	stb	r0, HSTATE_RESTORE_HID5(r13)
 
 	/* Load up guest SPRG3 value, since it's user readable */
-	lwz	r3, VCPU_SHAREDBE(r4)
-	cmpwi	r3, 0
-	ld	r5, VCPU_SHARED(r4)
+	lbz	r4, VCPU_SHAREDBE(r3)
+	cmpwi	r4, 0
+	ld	r5, VCPU_SHARED(r3)
 	beq	sprg3_little_endian
 sprg3_big_endian:
 #ifdef __BIG_ENDIAN__
-	ld	r3, VCPU_SHARED_SPRG3(r5)
+	ld	r4, VCPU_SHARED_SPRG3(r5)
 #else
 	addi	r5, r5, VCPU_SHARED_SPRG3
-	ldbrx	r3, 0, r5
+	ldbrx	r4, 0, r5
 #endif
 	b	after_sprg3_load
 sprg3_little_endian:
 #ifdef __LITTLE_ENDIAN__
-	ld	r3, VCPU_SHARED_SPRG3(r5)
+	ld	r4, VCPU_SHARED_SPRG3(r5)
 #else
 	addi	r5, r5, VCPU_SHARED_SPRG3
-	ldbrx	r3, 0, r5
+	ldbrx	r4, 0, r5
 #endif
 
 after_sprg3_load:
-	mtspr	SPRN_SPRG3, r3
+	mtspr	SPRN_SPRG3, r4
 #endif /* CONFIG_PPC_BOOK3S_64 */
 
-	PPC_LL	r4, VCPU_SHADOW_MSR(r4)	/* get shadow_msr */
+	PPC_LL	r4, VCPU_SHADOW_MSR(r3)	/* get shadow_msr */
 
 	/* Jump to segment patching handler and into our guest */
 	bl	FUNC(kvmppc_entry_trampoline)
@@ -146,7 +144,7 @@ after_sprg3_load:
 	 *
 	 */
 
-	PPC_LL	r3, GPR4(r1)		/* vcpu pointer */
+	PPC_LL	r3, GPR3(r1)		/* vcpu pointer */
 
 	/*
 	 * kvmppc_copy_from_svcpu can clobber volatile registers, save
@@ -169,7 +167,7 @@ after_sprg3_load:
 #endif /* CONFIG_PPC_BOOK3S_64 */
 
 	/* R7 = vcpu */
-	PPC_LL	r7, GPR4(r1)
+	PPC_LL	r7, GPR3(r1)
 
 	PPC_STL	r14, VCPU_GPR(R14)(r7)
 	PPC_STL	r15, VCPU_GPR(R15)(r7)
@@ -190,11 +188,11 @@ after_sprg3_load:
 	PPC_STL	r30, VCPU_GPR(R30)(r7)
 	PPC_STL	r31, VCPU_GPR(R31)(r7)
 
-	/* Pass the exit number as 3rd argument to kvmppc_handle_exit */
-	lwz	r5, VCPU_TRAP(r7)
+	/* Pass the exit number as 2nd argument to kvmppc_handle_exit */
+	lwz	r4, VCPU_TRAP(r7)
 
-	/* Restore r3 (kvm_run) and r4 (vcpu) */
-	REST_2GPRS(3, r1)
+	/* Restore r3 (vcpu) */
+	REST_GPR(3, r1)
 	bl	FUNC(kvmppc_handle_exit_pr)
 
 	/* If RESUME_GUEST, get back in the loop */
@@ -223,11 +221,11 @@ kvm_loop_heavyweight:
 	PPC_LL	r4, _LINK(r1)
 	PPC_STL r4, (PPC_LR_STKOFF + SWITCH_FRAME_SIZE)(r1)
 
-	/* Load vcpu and cpu_run */
-	REST_2GPRS(3, r1)
+	/* Load vcpu */
+	REST_GPR(3, r1)
 
 	/* Load non-volatile guest state from the vcpu */
-	VCPU_LOAD_NVGPRS(r4)
+	VCPU_LOAD_NVGPRS(r3)
 
 	/* Jump back into the beginning of this function */
 	b	kvm_start_lightweight
@@ -235,7 +233,7 @@ kvm_loop_heavyweight:
 kvm_loop_lightweight:
 
 	/* We'll need the vcpu pointer */
-	REST_GPR(4, r1)
+	REST_GPR(3, r1)
 
 	/* Jump back into the beginning of this function */
 	b	kvm_start_lightweight

arch/powerpc/kvm/book3s_pr.c

@@ -1151,9 +1151,9 @@ static int kvmppc_exit_pr_progint(struct kvm_vcpu *vcpu, unsigned int exit_nr)
 	return r;
 }
 
-int kvmppc_handle_exit_pr(struct kvm_run *run, struct kvm_vcpu *vcpu,
-			  unsigned int exit_nr)
+int kvmppc_handle_exit_pr(struct kvm_vcpu *vcpu, unsigned int exit_nr)
 {
+	struct kvm_run *run = vcpu->run;
 	int r = RESUME_HOST;
 	int s;
 
@@ -1826,12 +1826,11 @@ static void kvmppc_core_vcpu_free_pr(struct kvm_vcpu *vcpu)
 
 static int kvmppc_vcpu_run_pr(struct kvm_vcpu *vcpu)
 {
-	struct kvm_run *run = vcpu->run;
 	int ret;
 
 	/* Check if we can run the vcpu at all */
 	if (!vcpu->arch.sane) {
-		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 		ret = -EINVAL;
 		goto out;
 	}
@@ -1858,7 +1857,7 @@ static int kvmppc_vcpu_run_pr(struct kvm_vcpu *vcpu)
 
 	kvmppc_fix_ee_before_entry();
 
-	ret = __kvmppc_vcpu_run(run, vcpu);
+	ret = __kvmppc_vcpu_run(vcpu);
 
 	kvmppc_clear_debug(vcpu);
 

arch/powerpc/kvm/book3s_rtas.c

@@ -229,7 +229,9 @@ int kvmppc_rtas_hcall(struct kvm_vcpu *vcpu)
 	 */
 	args_phys = kvmppc_get_gpr(vcpu, 4) & KVM_PAM;
 
+	vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
 	rc = kvm_read_guest(vcpu->kvm, args_phys, &args, sizeof(args));
+	srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
 	if (rc)
 		goto fail;
 

arch/powerpc/kvm/booke.c

@@ -731,12 +731,11 @@ int kvmppc_core_check_requests(struct kvm_vcpu *vcpu)
 
 int kvmppc_vcpu_run(struct kvm_vcpu *vcpu)
 {
-	struct kvm_run *run = vcpu->run;
 	int ret, s;
 	struct debug_reg debug;
 
 	if (!vcpu->arch.sane) {
-		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 		return -EINVAL;
 	}
 
@@ -778,7 +777,7 @@ int kvmppc_vcpu_run(struct kvm_vcpu *vcpu)
 	vcpu->arch.pgdir = vcpu->kvm->mm->pgd;
 	kvmppc_fix_ee_before_entry();
 
-	ret = __kvmppc_vcpu_run(run, vcpu);
+	ret = __kvmppc_vcpu_run(vcpu);
 
 	/* No need for guest_exit. It's done in handle_exit.
 	   We also get here with interrupts enabled. */
@@ -982,9 +981,9 @@ static int kvmppc_resume_inst_load(struct kvm_vcpu *vcpu,
  *
  * Return value is in the form (errcode<<2 | RESUME_FLAG_HOST | RESUME_FLAG_NV)
  */
-int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
-                       unsigned int exit_nr)
+int kvmppc_handle_exit(struct kvm_vcpu *vcpu, unsigned int exit_nr)
 {
+	struct kvm_run *run = vcpu->run;
 	int r = RESUME_HOST;
 	int s;
 	int idx;

arch/powerpc/kvm/booke_interrupts.S

@@ -237,7 +237,7 @@ _GLOBAL(kvmppc_resume_host)
 	/* Switch to kernel stack and jump to handler. */
 	LOAD_REG_ADDR(r3, kvmppc_handle_exit)
 	mtctr	r3
-	lwz	r3, HOST_RUN(r1)
+	mr	r3, r4
 	lwz	r2, HOST_R2(r1)
 	mr	r14, r4 /* Save vcpu pointer. */
 
@@ -337,15 +337,14 @@ heavyweight_exit:
 
 
 /* Registers:
- *  r3: kvm_run pointer
- *  r4: vcpu pointer
+ *  r3: vcpu pointer
  */
 _GLOBAL(__kvmppc_vcpu_run)
 	stwu	r1, -HOST_STACK_SIZE(r1)
-	stw	r1, VCPU_HOST_STACK(r4)	/* Save stack pointer to vcpu. */
+	stw	r1, VCPU_HOST_STACK(r3)	/* Save stack pointer to vcpu. */
 
 	/* Save host state to stack. */
-	stw	r3, HOST_RUN(r1)
+	mr	r4, r3
 	mflr	r3
 	stw	r3, HOST_STACK_LR(r1)
 	mfcr	r5

arch/powerpc/kvm/bookehv_interrupts.S

@@ -434,9 +434,10 @@ _GLOBAL(kvmppc_resume_host)
 #endif
 
 	/* Switch to kernel stack and jump to handler. */
-	PPC_LL	r3, HOST_RUN(r1)
+	mr	r3, r4
 	mr	r5, r14 /* intno */
 	mr	r14, r4 /* Save vcpu pointer. */
+	mr	r4, r5
 	bl	kvmppc_handle_exit
 
 	/* Restore vcpu pointer and the nonvolatiles we used. */
@@ -525,15 +526,14 @@ heavyweight_exit:
 	blr
 
 /* Registers:
- *  r3: kvm_run pointer
- *  r4: vcpu pointer
+ *  r3: vcpu pointer
  */
 _GLOBAL(__kvmppc_vcpu_run)
 	stwu	r1, -HOST_STACK_SIZE(r1)
-	PPC_STL	r1, VCPU_HOST_STACK(r4)	/* Save stack pointer to vcpu. */
+	PPC_STL	r1, VCPU_HOST_STACK(r3)	/* Save stack pointer to vcpu. */
 
 	/* Save host state to stack. */
-	PPC_STL	r3, HOST_RUN(r1)
+	mr	r4, r3
 	mflr	r3
 	mfcr	r5
 	PPC_STL	r3, HOST_STACK_LR(r1)

arch/powerpc/kvm/powerpc.c

@@ -403,7 +403,10 @@ int kvmppc_ld(struct kvm_vcpu *vcpu, ulong *eaddr, int size, void *ptr,
 		return EMULATE_DONE;
 	}
 
-	if (kvm_read_guest(vcpu->kvm, pte.raddr, ptr, size))
+	vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
+	rc = kvm_read_guest(vcpu->kvm, pte.raddr, ptr, size);
+	srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
+	if (rc)
 		return EMULATE_DO_MMIO;
 
 	return EMULATE_DONE;