KVM: PPC: e500: refactor core-specific TLB code

The PID handling is e500v1/v2-specific, and is moved to e500.c.

The MMU sregs code and kvmppc_core_vcpu_translate will be shared with
e500mc, and is moved from e500.c to e500_tlb.c.

Partially based on patches from Liu Yu <yu.liu@freescale.com>.

Signed-off-by: Scott Wood <scottwood@freescale.com>
[agraf: fix bisectability]
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 305 insertions, 52 deletions

diff --git a/arch/powerpc/kvm/e500.c b/arch/powerpc/kvm/e500.c
index 76b35d8f099f..b479ed77c515 100644
--- a/arch/powerpc/kvm/e500.c
+++ b/arch/powerpc/kvm/e500.c
@@ -22,9 +22,281 @@
 #include <asm/tlbflush.h>
 #include <asm/kvm_ppc.h>
 
+#include "../mm/mmu_decl.h"
 #include "booke.h"
 #include "e500.h"
 
+struct id {
+	unsigned long val;
+	struct id **pentry;
+};
+
+#define NUM_TIDS 256
+
+/*
+ * This table provide mappings from:
+ * (guestAS,guestTID,guestPR) --> ID of physical cpu
+ * guestAS	[0..1]
+ * guestTID	[0..255]
+ * guestPR	[0..1]
+ * ID		[1..255]
+ * Each vcpu keeps one vcpu_id_table.
+ */
+struct vcpu_id_table {
+	struct id id[2][NUM_TIDS][2];
+};
+
+/*
+ * This table provide reversed mappings of vcpu_id_table:
+ * ID --> address of vcpu_id_table item.
+ * Each physical core has one pcpu_id_table.
+ */
+struct pcpu_id_table {
+	struct id *entry[NUM_TIDS];
+};
+
+static DEFINE_PER_CPU(struct pcpu_id_table, pcpu_sids);
+
+/* This variable keeps last used shadow ID on local core.
+ * The valid range of shadow ID is [1..255] */
+static DEFINE_PER_CPU(unsigned long, pcpu_last_used_sid);
+
+/*
+ * Allocate a free shadow id and setup a valid sid mapping in given entry.
+ * A mapping is only valid when vcpu_id_table and pcpu_id_table are match.
+ *
+ * The caller must have preemption disabled, and keep it that way until
+ * it has finished with the returned shadow id (either written into the
+ * TLB or arch.shadow_pid, or discarded).
+ */
+static inline int local_sid_setup_one(struct id *entry)
+{
+	unsigned long sid;
+	int ret = -1;
+
+	sid = ++(__get_cpu_var(pcpu_last_used_sid));
+	if (sid < NUM_TIDS) {
+		__get_cpu_var(pcpu_sids).entry[sid] = entry;
+		entry->val = sid;
+		entry->pentry = &__get_cpu_var(pcpu_sids).entry[sid];
+		ret = sid;
+	}
+
+	/*
+	 * If sid == NUM_TIDS, we've run out of sids.  We return -1, and
+	 * the caller will invalidate everything and start over.
+	 *
+	 * sid > NUM_TIDS indicates a race, which we disable preemption to
+	 * avoid.
+	 */
+	WARN_ON(sid > NUM_TIDS);
+
+	return ret;
+}
+
+/*
+ * Check if given entry contain a valid shadow id mapping.
+ * An ID mapping is considered valid only if
+ * both vcpu and pcpu know this mapping.
+ *
+ * The caller must have preemption disabled, and keep it that way until
+ * it has finished with the returned shadow id (either written into the
+ * TLB or arch.shadow_pid, or discarded).
+ */
+static inline int local_sid_lookup(struct id *entry)
+{
+	if (entry && entry->val != 0 &&
+	    __get_cpu_var(pcpu_sids).entry[entry->val] == entry &&
+	    entry->pentry == &__get_cpu_var(pcpu_sids).entry[entry->val])
+		return entry->val;
+	return -1;
+}
+
+/* Invalidate all id mappings on local core -- call with preempt disabled */
+static inline void local_sid_destroy_all(void)
+{
+	__get_cpu_var(pcpu_last_used_sid) = 0;
+	memset(&__get_cpu_var(pcpu_sids), 0, sizeof(__get_cpu_var(pcpu_sids)));
+}
+
+static void *kvmppc_e500_id_table_alloc(struct kvmppc_vcpu_e500 *vcpu_e500)
+{
+	vcpu_e500->idt = kzalloc(sizeof(struct vcpu_id_table), GFP_KERNEL);
+	return vcpu_e500->idt;
+}
+
+static void kvmppc_e500_id_table_free(struct kvmppc_vcpu_e500 *vcpu_e500)
+{
+	kfree(vcpu_e500->idt);
+	vcpu_e500->idt = NULL;
+}
+
+/* Map guest pid to shadow.
+ * We use PID to keep shadow of current guest non-zero PID,
+ * and use PID1 to keep shadow of guest zero PID.
+ * So that guest tlbe with TID=0 can be accessed at any time */
+static void kvmppc_e500_recalc_shadow_pid(struct kvmppc_vcpu_e500 *vcpu_e500)
+{
+	preempt_disable();
+	vcpu_e500->vcpu.arch.shadow_pid = kvmppc_e500_get_sid(vcpu_e500,
+			get_cur_as(&vcpu_e500->vcpu),
+			get_cur_pid(&vcpu_e500->vcpu),
+			get_cur_pr(&vcpu_e500->vcpu), 1);
+	vcpu_e500->vcpu.arch.shadow_pid1 = kvmppc_e500_get_sid(vcpu_e500,
+			get_cur_as(&vcpu_e500->vcpu), 0,
+			get_cur_pr(&vcpu_e500->vcpu), 1);
+	preempt_enable();
+}
+
+/* Invalidate all mappings on vcpu */
+static void kvmppc_e500_id_table_reset_all(struct kvmppc_vcpu_e500 *vcpu_e500)
+{
+	memset(vcpu_e500->idt, 0, sizeof(struct vcpu_id_table));
+
+	/* Update shadow pid when mappings are changed */
+	kvmppc_e500_recalc_shadow_pid(vcpu_e500);
+}
+
+/* Invalidate one ID mapping on vcpu */
+static inline void kvmppc_e500_id_table_reset_one(
+			       struct kvmppc_vcpu_e500 *vcpu_e500,
+			       int as, int pid, int pr)
+{
+	struct vcpu_id_table *idt = vcpu_e500->idt;
+
+	BUG_ON(as >= 2);
+	BUG_ON(pid >= NUM_TIDS);
+	BUG_ON(pr >= 2);
+
+	idt->id[as][pid][pr].val = 0;
+	idt->id[as][pid][pr].pentry = NULL;
+
+	/* Update shadow pid when mappings are changed */
+	kvmppc_e500_recalc_shadow_pid(vcpu_e500);
+}
+
+/*
+ * Map guest (vcpu,AS,ID,PR) to physical core shadow id.
+ * This function first lookup if a valid mapping exists,
+ * if not, then creates a new one.
+ *
+ * The caller must have preemption disabled, and keep it that way until
+ * it has finished with the returned shadow id (either written into the
+ * TLB or arch.shadow_pid, or discarded).
+ */
+unsigned int kvmppc_e500_get_sid(struct kvmppc_vcpu_e500 *vcpu_e500,
+				 unsigned int as, unsigned int gid,
+				 unsigned int pr, int avoid_recursion)
+{
+	struct vcpu_id_table *idt = vcpu_e500->idt;
+	int sid;
+
+	BUG_ON(as >= 2);
+	BUG_ON(gid >= NUM_TIDS);
+	BUG_ON(pr >= 2);
+
+	sid = local_sid_lookup(&idt->id[as][gid][pr]);
+
+	while (sid <= 0) {
+		/* No mapping yet */
+		sid = local_sid_setup_one(&idt->id[as][gid][pr]);
+		if (sid <= 0) {
+			_tlbil_all();
+			local_sid_destroy_all();
+		}
+
+		/* Update shadow pid when mappings are changed */
+		if (!avoid_recursion)
+			kvmppc_e500_recalc_shadow_pid(vcpu_e500);
+	}
+
+	return sid;
+}
+
+unsigned int kvmppc_e500_get_tlb_stid(struct kvm_vcpu *vcpu,
+				      struct kvm_book3e_206_tlb_entry *gtlbe)
+{
+	return kvmppc_e500_get_sid(to_e500(vcpu), get_tlb_ts(gtlbe),
+				   get_tlb_tid(gtlbe), get_cur_pr(vcpu), 0);
+}
+
+void kvmppc_set_pid(struct kvm_vcpu *vcpu, u32 pid)
+{
+	struct kvmppc_vcpu_e500 *vcpu_e500 = to_e500(vcpu);
+
+	if (vcpu->arch.pid != pid) {
+		vcpu_e500->pid[0] = vcpu->arch.pid = pid;
+		kvmppc_e500_recalc_shadow_pid(vcpu_e500);
+	}
+}
+
+/* gtlbe must not be mapped by more than one host tlbe */
+void kvmppc_e500_tlbil_one(struct kvmppc_vcpu_e500 *vcpu_e500,
+                           struct kvm_book3e_206_tlb_entry *gtlbe)
+{
+	struct vcpu_id_table *idt = vcpu_e500->idt;
+	unsigned int pr, tid, ts, pid;
+	u32 val, eaddr;
+	unsigned long flags;
+
+	ts = get_tlb_ts(gtlbe);
+	tid = get_tlb_tid(gtlbe);
+
+	preempt_disable();
+
+	/* One guest ID may be mapped to two shadow IDs */
+	for (pr = 0; pr < 2; pr++) {
+		/*
+		 * The shadow PID can have a valid mapping on at most one
+		 * host CPU.  In the common case, it will be valid on this
+		 * CPU, in which case we do a local invalidation of the
+		 * specific address.
+		 *
+		 * If the shadow PID is not valid on the current host CPU,
+		 * we invalidate the entire shadow PID.
+		 */
+		pid = local_sid_lookup(&idt->id[ts][tid][pr]);
+		if (pid <= 0) {
+			kvmppc_e500_id_table_reset_one(vcpu_e500, ts, tid, pr);
+			continue;
+		}
+
+		/*
+		 * The guest is invalidating a 4K entry which is in a PID
+		 * that has a valid shadow mapping on this host CPU.  We
+		 * search host TLB to invalidate it's shadow TLB entry,
+		 * similar to __tlbil_va except that we need to look in AS1.
+		 */
+		val = (pid << MAS6_SPID_SHIFT) | MAS6_SAS;
+		eaddr = get_tlb_eaddr(gtlbe);
+
+		local_irq_save(flags);
+
+		mtspr(SPRN_MAS6, val);
+		asm volatile("tlbsx 0, %[eaddr]" : : [eaddr] "r" (eaddr));
+		val = mfspr(SPRN_MAS1);
+		if (val & MAS1_VALID) {
+			mtspr(SPRN_MAS1, val & ~MAS1_VALID);
+			asm volatile("tlbwe");
+		}
+
+		local_irq_restore(flags);
+	}
+
+	preempt_enable();
+}
+
+void kvmppc_e500_tlbil_all(struct kvmppc_vcpu_e500 *vcpu_e500)
+{
+	kvmppc_e500_id_table_reset_all(vcpu_e500);
+}
+
+void kvmppc_mmu_msr_notify(struct kvm_vcpu *vcpu, u32 old_msr)
+{
+	/* Recalc shadow pid since MSR changes */
+	kvmppc_e500_recalc_shadow_pid(to_e500(vcpu));
+}
+
 void kvmppc_core_load_host_debugstate(struct kvm_vcpu *vcpu)
 {
 }
@@ -36,13 +308,13 @@ void kvmppc_core_load_guest_debugstate(struct kvm_vcpu *vcpu)
 void kvmppc_core_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 {
 	kvmppc_booke_vcpu_load(vcpu, cpu);
-	kvmppc_e500_tlb_load(vcpu, cpu);
+
+	/* Shadow PID may be expired on local core */
+	kvmppc_e500_recalc_shadow_pid(to_e500(vcpu));
 }
 
 void kvmppc_core_vcpu_put(struct kvm_vcpu *vcpu)
 {
-	kvmppc_e500_tlb_put(vcpu);
-
 #ifdef CONFIG_SPE
 	if (vcpu->arch.shadow_msr & MSR_SPE)
 		kvmppc_vcpu_disable_spe(vcpu);
@@ -63,6 +335,23 @@ int kvmppc_core_check_processor_compat(void)
 	return r;
 }
 
+static void kvmppc_e500_tlb_setup(struct kvmppc_vcpu_e500 *vcpu_e500)
+{
+	struct kvm_book3e_206_tlb_entry *tlbe;
+
+	/* Insert large initial mapping for guest. */
+	tlbe = get_entry(vcpu_e500, 1, 0);
+	tlbe->mas1 = MAS1_VALID | MAS1_TSIZE(BOOK3E_PAGESZ_256M);
+	tlbe->mas2 = 0;
+	tlbe->mas7_3 = E500_TLB_SUPER_PERM_MASK;
+
+	/* 4K map for serial output. Used by kernel wrapper. */
+	tlbe = get_entry(vcpu_e500, 1, 1);
+	tlbe->mas1 = MAS1_VALID | MAS1_TSIZE(BOOK3E_PAGESZ_4K);
+	tlbe->mas2 = (0xe0004500 & 0xFFFFF000) | MAS2_I | MAS2_G;
+	tlbe->mas7_3 = (0xe0004500 & 0xFFFFF000) | E500_TLB_SUPER_PERM_MASK;
+}
+
 int kvmppc_core_vcpu_setup(struct kvm_vcpu *vcpu)
 {
 	struct kvmppc_vcpu_e500 *vcpu_e500 = to_e500(vcpu);
@@ -78,32 +367,6 @@ int kvmppc_core_vcpu_setup(struct kvm_vcpu *vcpu)
 	return 0;
 }
 
-/* 'linear_address' is actually an encoding of AS|PID|EADDR . */
-int kvmppc_core_vcpu_translate(struct kvm_vcpu *vcpu,
-                               struct kvm_translation *tr)
-{
-	int index;
-	gva_t eaddr;
-	u8 pid;
-	u8 as;
-
-	eaddr = tr->linear_address;
-	pid = (tr->linear_address >> 32) & 0xff;
-	as = (tr->linear_address >> 40) & 0x1;
-
-	index = kvmppc_e500_tlb_search(vcpu, eaddr, pid, as);
-	if (index < 0) {
-		tr->valid = 0;
-		return 0;
-	}
-
-	tr->physical_address = kvmppc_mmu_xlate(vcpu, index, eaddr);
-	/* XXX what does "writeable" and "usermode" even mean? */
-	tr->valid = 1;
-
-	return 0;
-}
-
 void kvmppc_core_get_sregs(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs)
 {
 	struct kvmppc_vcpu_e500 *vcpu_e500 = to_e500(vcpu);
@@ -117,19 +380,6 @@ void kvmppc_core_get_sregs(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs)
 	sregs->u.e.impl.fsl.hid0 = vcpu_e500->hid0;
 	sregs->u.e.impl.fsl.mcar = vcpu_e500->mcar;
 
-	sregs->u.e.mas0 = vcpu->arch.shared->mas0;
-	sregs->u.e.mas1 = vcpu->arch.shared->mas1;
-	sregs->u.e.mas2 = vcpu->arch.shared->mas2;
-	sregs->u.e.mas7_3 = vcpu->arch.shared->mas7_3;
-	sregs->u.e.mas4 = vcpu->arch.shared->mas4;
-	sregs->u.e.mas6 = vcpu->arch.shared->mas6;
-
-	sregs->u.e.mmucfg = mfspr(SPRN_MMUCFG);
-	sregs->u.e.tlbcfg[0] = vcpu_e500->tlb0cfg;
-	sregs->u.e.tlbcfg[1] = vcpu_e500->tlb1cfg;
-	sregs->u.e.tlbcfg[2] = 0;
-	sregs->u.e.tlbcfg[3] = 0;
-
 	sregs->u.e.ivor_high[0] = vcpu->arch.ivor[BOOKE_IRQPRIO_SPE_UNAVAIL];
 	sregs->u.e.ivor_high[1] = vcpu->arch.ivor[BOOKE_IRQPRIO_SPE_FP_DATA];
 	sregs->u.e.ivor_high[2] = vcpu->arch.ivor[BOOKE_IRQPRIO_SPE_FP_ROUND];
@@ -137,11 +387,13 @@ void kvmppc_core_get_sregs(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs)
 		vcpu->arch.ivor[BOOKE_IRQPRIO_PERFORMANCE_MONITOR];
 
 	kvmppc_get_sregs_ivor(vcpu, sregs);
+	kvmppc_get_sregs_e500_tlb(vcpu, sregs);
 }
 
 int kvmppc_core_set_sregs(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs)
 {
 	struct kvmppc_vcpu_e500 *vcpu_e500 = to_e500(vcpu);
+	int ret;
 
 	if (sregs->u.e.impl_id == KVM_SREGS_E_IMPL_FSL) {
 		vcpu_e500->svr = sregs->u.e.impl.fsl.svr;
@@ -149,14 +401,9 @@ int kvmppc_core_set_sregs(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs)
 		vcpu_e500->mcar = sregs->u.e.impl.fsl.mcar;
 	}
 
-	if (sregs->u.e.features & KVM_SREGS_E_ARCH206_MMU) {
-		vcpu->arch.shared->mas0 = sregs->u.e.mas0;
-		vcpu->arch.shared->mas1 = sregs->u.e.mas1;
-		vcpu->arch.shared->mas2 = sregs->u.e.mas2;
-		vcpu->arch.shared->mas7_3 = sregs->u.e.mas7_3;
-		vcpu->arch.shared->mas4 = sregs->u.e.mas4;
-		vcpu->arch.shared->mas6 = sregs->u.e.mas6;
-	}
+	ret = kvmppc_set_sregs_e500_tlb(vcpu, sregs);
+	if (ret < 0)
+		return ret;
 
 	if (!(sregs->u.e.features & KVM_SREGS_E_IVOR))
 		return 0;
@@ -195,9 +442,12 @@ struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id)
 	if (err)
 		goto free_vcpu;
 
+	if (kvmppc_e500_id_table_alloc(vcpu_e500) == NULL)
+		goto uninit_vcpu;
+
 	err = kvmppc_e500_tlb_init(vcpu_e500);
 	if (err)
-		goto uninit_vcpu;
+		goto uninit_id;
 
 	vcpu->arch.shared = (void*)__get_free_page(GFP_KERNEL|__GFP_ZERO);
 	if (!vcpu->arch.shared)
@@ -207,6 +457,8 @@ struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id)
 
 uninit_tlb:
 	kvmppc_e500_tlb_uninit(vcpu_e500);
+uninit_id:
+	kvmppc_e500_id_table_free(vcpu_e500);
 uninit_vcpu:
 	kvm_vcpu_uninit(vcpu);
 free_vcpu:
@@ -220,8 +472,9 @@ void kvmppc_core_vcpu_free(struct kvm_vcpu *vcpu)
 	struct kvmppc_vcpu_e500 *vcpu_e500 = to_e500(vcpu);
 
 	free_page((unsigned long)vcpu->arch.shared);
-	kvm_vcpu_uninit(vcpu);
 	kvmppc_e500_tlb_uninit(vcpu_e500);
+	kvmppc_e500_id_table_free(vcpu_e500);
+	kvm_vcpu_uninit(vcpu);
 	kmem_cache_free(kvm_vcpu_cache, vcpu_e500);
 }