KVM: PPC: Book3S HV: Store LPCR value for each virtual core

This adds the ability to have a separate LPCR (Logical Partitioning
Control Register) value relating to a guest for each virtual core,
rather than only having a single value for the whole VM.  This
corresponds to what real POWER hardware does, where there is a LPCR
per CPU thread but most of the fields are required to have the same
value on all active threads in a core.

The per-virtual-core LPCR can be read and written using the
GET/SET_ONE_REG interface.  Userspace can can only modify the
following fields of the LPCR value:

DPFD	Default prefetch depth
ILE	Interrupt little-endian
TC	Translation control (secondary HPT hash group search disable)

We still maintain a per-VM default LPCR value in kvm->arch.lpcr, which
contains bits relating to memory management, i.e. the Virtualized
Partition Memory (VPM) bits and the bits relating to guest real mode.
When this default value is updated, the update needs to be propagated
to the per-vcore values, so we add a kvmppc_update_lpcr() helper to do
that.
Signed-off-by: Paul Mackerras <paulus@samba.org>
[agraf: fix whitespace]
Signed-off-by: Alexander Graf <agraf@suse.de>

Documentation/virtual/kvm/api.txt

@@ -1835,6 +1835,7 @@ registers, find a list below:
   PPC   | KVM_REG_PPC_PID	| 64
   PPC   | KVM_REG_PPC_ACOP	| 64
   PPC   | KVM_REG_PPC_VRSAVE	| 32
+  PPC   | KVM_REG_PPC_LPCR	| 64
   PPC   | KVM_REG_PPC_TM_GPR0	| 64
           ...
   PPC   | KVM_REG_PPC_TM_GPR31	| 64

arch/powerpc/include/asm/kvm_book3s.h

@@ -172,6 +172,8 @@ extern long kvmppc_do_h_remove(struct kvm *kvm, unsigned long flags,
 			unsigned long *hpret);
 extern long kvmppc_hv_get_dirty_log(struct kvm *kvm,
 			struct kvm_memory_slot *memslot, unsigned long *map);
+extern void kvmppc_update_lpcr(struct kvm *kvm, unsigned long lpcr,
+			unsigned long mask);
 
 extern void kvmppc_entry_trampoline(void);
 extern void kvmppc_hv_entry_trampoline(void);

arch/powerpc/include/asm/kvm_host.h

@@ -290,6 +290,7 @@ struct kvmppc_vcore {
 	u64 preempt_tb;
 	struct kvm_vcpu *runner;
 	u64 tb_offset;		/* guest timebase - host timebase */
+	ulong lpcr;
 };
 
 #define VCORE_ENTRY_COUNT(vc)	((vc)->entry_exit_count & 0xff)

arch/powerpc/include/asm/reg.h

@@ -284,6 +284,7 @@
 #define   LPCR_ISL	(1ul << (63-2))
 #define   LPCR_VC_SH	(63-2)
 #define   LPCR_DPFD_SH	(63-11)
+#define   LPCR_DPFD	(7ul << LPCR_DPFD_SH)
 #define   LPCR_VRMASD	(0x1ful << (63-16))
 #define   LPCR_VRMA_L	(1ul << (63-12))
 #define   LPCR_VRMA_LP0	(1ul << (63-15))
@@ -300,6 +301,7 @@
 #define     LPCR_PECE2	0x00001000	/* machine check etc can cause exit */
 #define   LPCR_MER	0x00000800	/* Mediated External Exception */
 #define   LPCR_MER_SH	11
+#define   LPCR_TC      0x00000200	/* Translation control */
 #define   LPCR_LPES    0x0000000c
 #define   LPCR_LPES0   0x00000008      /* LPAR Env selector 0 */
 #define   LPCR_LPES1   0x00000004      /* LPAR Env selector 1 */
@@ -421,6 +423,7 @@
 #define	 HID4_RMLS2_SH	 (63 - 2)	/* Real mode limit bottom 2 bits */
 #define	 HID4_LPID5_SH	 (63 - 6)	/* partition ID bottom 4 bits */
 #define	 HID4_RMOR_SH	 (63 - 22)	/* real mode offset (16 bits) */
+#define  HID4_RMOR	 (0xFFFFul << HID4_RMOR_SH)
 #define  HID4_LPES1	 (1 << (63-57))	/* LPAR env. sel. bit 1 */
 #define  HID4_RMLS0_SH	 (63 - 58)	/* Real mode limit top bit */
 #define	 HID4_LPID1_SH	 0		/* partition ID top 2 bits */

arch/powerpc/include/uapi/asm/kvm.h

@@ -533,6 +533,7 @@ struct kvm_get_htab_header {
 #define KVM_REG_PPC_ACOP	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xb3)
 
 #define KVM_REG_PPC_VRSAVE	(KVM_REG_PPC | KVM_REG_SIZE_U32 | 0xb4)
+#define KVM_REG_PPC_LPCR	(KVM_REG_PPC | KVM_REG_SIZE_U32 | 0xb5)
 
 /* Transactional Memory checkpointed state:
  * This is all GPRs, all VSX regs and a subset of SPRs

arch/powerpc/kernel/asm-offsets.c

@@ -524,6 +524,7 @@ int main(void)
 	DEFINE(VCORE_IN_GUEST, offsetof(struct kvmppc_vcore, in_guest));
 	DEFINE(VCORE_NAPPING_THREADS, offsetof(struct kvmppc_vcore, napping_threads));
 	DEFINE(VCORE_TB_OFFSET, offsetof(struct kvmppc_vcore, tb_offset));
+	DEFINE(VCORE_LPCR, offsetof(struct kvmppc_vcore, lpcr));
 	DEFINE(VCPU_SVCPU, offsetof(struct kvmppc_vcpu_book3s, shadow_vcpu) -
 			   offsetof(struct kvmppc_vcpu_book3s, vcpu));
 	DEFINE(VCPU_SLB_E, offsetof(struct kvmppc_slb, orige));

arch/powerpc/kvm/book3s_64_mmu_hv.c

@@ -1512,9 +1512,8 @@ static ssize_t kvm_htab_write(struct file *file, const char __user *buf,
 
 				kvm->arch.vrma_slb_v = senc | SLB_VSID_B_1T |
 					(VRMA_VSID << SLB_VSID_SHIFT_1T);
-				lpcr = kvm->arch.lpcr & ~LPCR_VRMASD;
-				lpcr |= senc << (LPCR_VRMASD_SH - 4);
-				kvm->arch.lpcr = lpcr;
+				lpcr = senc << (LPCR_VRMASD_SH - 4);
+				kvmppc_update_lpcr(kvm, lpcr, LPCR_VRMASD);
 				rma_setup = 1;
 			}
 			++i;

arch/powerpc/kvm/book3s_hv.c

@@ -195,7 +195,7 @@ void kvmppc_dump_regs(struct kvm_vcpu *vcpu)
 		pr_err("  ESID = %.16llx VSID = %.16llx\n",
 		       vcpu->arch.slb[r].orige, vcpu->arch.slb[r].origv);
 	pr_err("lpcr = %.16lx sdr1 = %.16lx last_inst = %.8x\n",
-	       vcpu->kvm->arch.lpcr, vcpu->kvm->arch.sdr1,
+	       vcpu->arch.vcore->lpcr, vcpu->kvm->arch.sdr1,
 	       vcpu->arch.last_inst);
 }
 
@@ -723,6 +723,21 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
 	return 0;
 }
 
+static void kvmppc_set_lpcr(struct kvm_vcpu *vcpu, u64 new_lpcr)
+{
+	struct kvmppc_vcore *vc = vcpu->arch.vcore;
+	u64 mask;
+
+	spin_lock(&vc->lock);
+	/*
+	 * Userspace can only modify DPFD (default prefetch depth),
+	 * ILE (interrupt little-endian) and TC (translation control).
+	 */
+	mask = LPCR_DPFD | LPCR_ILE | LPCR_TC;
+	vc->lpcr = (vc->lpcr & ~mask) | (new_lpcr & mask);
+	spin_unlock(&vc->lock);
+}
+
 int kvmppc_get_one_reg(struct kvm_vcpu *vcpu, u64 id, union kvmppc_one_reg *val)
 {
 	int r = 0;
@@ -805,6 +820,9 @@ int kvmppc_get_one_reg(struct kvm_vcpu *vcpu, u64 id, union kvmppc_one_reg *val)
 	case KVM_REG_PPC_TB_OFFSET:
 		*val = get_reg_val(id, vcpu->arch.vcore->tb_offset);
 		break;
+	case KVM_REG_PPC_LPCR:
+		*val = get_reg_val(id, vcpu->arch.vcore->lpcr);
+		break;
 	default:
 		r = -EINVAL;
 		break;
@@ -909,6 +927,9 @@ int kvmppc_set_one_reg(struct kvm_vcpu *vcpu, u64 id, union kvmppc_one_reg *val)
 		vcpu->arch.vcore->tb_offset =
 			ALIGN(set_reg_val(id, *val), 1UL << 24);
 		break;
+	case KVM_REG_PPC_LPCR:
+		kvmppc_set_lpcr(vcpu, set_reg_val(id, *val));
+		break;
 	default:
 		r = -EINVAL;
 		break;
@@ -969,6 +990,7 @@ struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id)
 			spin_lock_init(&vcore->lock);
 			init_waitqueue_head(&vcore->wq);
 			vcore->preempt_tb = TB_NIL;
+			vcore->lpcr = kvm->arch.lpcr;
 		}
 		kvm->arch.vcores[core] = vcore;
 		kvm->arch.online_vcores++;
@@ -1758,6 +1780,32 @@ void kvmppc_core_commit_memory_region(struct kvm *kvm,
 	}
 }
 
+/*
+ * Update LPCR values in kvm->arch and in vcores.
+ * Caller must hold kvm->lock.
+ */
+void kvmppc_update_lpcr(struct kvm *kvm, unsigned long lpcr, unsigned long mask)
+{
+	long int i;
+	u32 cores_done = 0;
+
+	if ((kvm->arch.lpcr & mask) == lpcr)
+		return;
+
+	kvm->arch.lpcr = (kvm->arch.lpcr & ~mask) | lpcr;
+
+	for (i = 0; i < KVM_MAX_VCORES; ++i) {
+		struct kvmppc_vcore *vc = kvm->arch.vcores[i];
+		if (!vc)
+			continue;
+		spin_lock(&vc->lock);
+		vc->lpcr = (vc->lpcr & ~mask) | lpcr;
+		spin_unlock(&vc->lock);
+		if (++cores_done >= kvm->arch.online_vcores)
+			break;
+	}
+}
+
 static int kvmppc_hv_setup_htab_rma(struct kvm_vcpu *vcpu)
 {
 	int err = 0;
@@ -1766,7 +1814,8 @@ static int kvmppc_hv_setup_htab_rma(struct kvm_vcpu *vcpu)
 	unsigned long hva;
 	struct kvm_memory_slot *memslot;
 	struct vm_area_struct *vma;
-	unsigned long lpcr, senc;
+	unsigned long lpcr = 0, senc;
+	unsigned long lpcr_mask = 0;
 	unsigned long psize, porder;
 	unsigned long rma_size;
 	unsigned long rmls;
@@ -1831,9 +1880,9 @@ static int kvmppc_hv_setup_htab_rma(struct kvm_vcpu *vcpu)
 		senc = slb_pgsize_encoding(psize);
 		kvm->arch.vrma_slb_v = senc | SLB_VSID_B_1T |
 			(VRMA_VSID << SLB_VSID_SHIFT_1T);
-		lpcr = kvm->arch.lpcr & ~LPCR_VRMASD;
-		lpcr |= senc << (LPCR_VRMASD_SH - 4);
-		kvm->arch.lpcr = lpcr;
+		lpcr_mask = LPCR_VRMASD;
+		/* the -4 is to account for senc values starting at 0x10 */
+		lpcr = senc << (LPCR_VRMASD_SH - 4);
 
 		/* Create HPTEs in the hash page table for the VRMA */
 		kvmppc_map_vrma(vcpu, memslot, porder);
@@ -1854,23 +1903,21 @@ static int kvmppc_hv_setup_htab_rma(struct kvm_vcpu *vcpu)
 		kvm->arch.rma = ri;
 
 		/* Update LPCR and RMOR */
-		lpcr = kvm->arch.lpcr;
 		if (cpu_has_feature(CPU_FTR_ARCH_201)) {
 			/* PPC970; insert RMLS value (split field) in HID4 */
-			lpcr &= ~((1ul << HID4_RMLS0_SH) |
-				  (3ul << HID4_RMLS2_SH));
-			lpcr |= ((rmls >> 2) << HID4_RMLS0_SH) |
+			lpcr_mask = (1ul << HID4_RMLS0_SH) |
+				(3ul << HID4_RMLS2_SH) | HID4_RMOR;
+			lpcr = ((rmls >> 2) << HID4_RMLS0_SH) |
 				((rmls & 3) << HID4_RMLS2_SH);
 			/* RMOR is also in HID4 */
 			lpcr |= ((ri->base_pfn >> (26 - PAGE_SHIFT)) & 0xffff)
 				<< HID4_RMOR_SH;
 		} else {
 			/* POWER7 */
-			lpcr &= ~(LPCR_VPM0 | LPCR_VRMA_L);
-			lpcr |= rmls << LPCR_RMLS_SH;
+			lpcr_mask = LPCR_VPM0 | LPCR_VRMA_L | LPCR_RMLS;
+			lpcr = rmls << LPCR_RMLS_SH;
 			kvm->arch.rmor = ri->base_pfn << PAGE_SHIFT;
 		}
-		kvm->arch.lpcr = lpcr;
 		pr_info("KVM: Using RMO at %lx size %lx (LPCR = %lx)\n",
 			ri->base_pfn << PAGE_SHIFT, rma_size, lpcr);
 
@@ -1889,6 +1936,8 @@ static int kvmppc_hv_setup_htab_rma(struct kvm_vcpu *vcpu)
 		}
 	}
 
+	kvmppc_update_lpcr(kvm, lpcr, lpcr_mask);
+
 	/* Order updates to kvm->arch.lpcr etc. vs. rma_setup_done */
 	smp_wmb();
 	kvm->arch.rma_setup_done = 1;

arch/powerpc/kvm/book3s_hv_rmhandlers.S

@@ -509,7 +509,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
 	beq	20b
 
 	/* Set LPCR and RMOR. */
-10:	ld	r8,KVM_LPCR(r9)
+10:	ld	r8,VCORE_LPCR(r5)
 	mtspr	SPRN_LPCR,r8
 	ld	r8,KVM_RMOR(r9)
 	mtspr	SPRN_RMOR,r8
@@ -571,7 +571,8 @@ toc_tlbie_lock:
 	bne	24b
 	isync
 
-	ld	r7,KVM_LPCR(r9)		/* use kvm->arch.lpcr to store HID4 */
+	ld	r5,HSTATE_KVM_VCORE(r13)
+	ld	r7,VCORE_LPCR(r5)	/* use vcore->lpcr to store HID4 */
 	li	r0,0x18f
 	rotldi	r0,r0,HID4_LPID5_SH	/* all lpid bits in HID4 = 1 */
 	or	r0,r7,r0