[PATCH 10/30] KVM: PPC: e500: Track TLB1 entries with a bitmap

[Alexander Graf <agraf@suse.de>]

From: Scott Wood <scottwood@freescale.com>

Rather than invalidate everything when a TLB1 entry needs to be
taken down, keep track of which host TLB1 entries are used for
a given guest TLB1 entry, and invalidate just those entries.

Based on code from Ashish Kalra <Ashish.Kalra@freescale.com>
and Liu Yu <yu.liu@freescale.com>.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
---
 arch/powerpc/kvm/e500.h     |    5 +++
 arch/powerpc/kvm/e500_tlb.c |   72 ++++++++++++++++++++++++++++++++++++++++---
 2 files changed, 72 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/kvm/e500.h b/arch/powerpc/kvm/e500.h
index 34cef08..f4dee55 100644
--- a/arch/powerpc/kvm/e500.h
+++ b/arch/powerpc/kvm/e500.h
@@ -2,6 +2,7 @@
  * Copyright (C) 2008-2011 Freescale Semiconductor, Inc. All rights reserved.
  *
  * Author: Yu Liu <yu.liu@freescale.com>
+ *         Ashish Kalra <ashish.kalra@freescale.com>
  *
  * Description:
  * This file is based on arch/powerpc/kvm/44x_tlb.h and
@@ -25,6 +26,7 @@
 
 #define E500_TLB_VALID 1
 #define E500_TLB_DIRTY 2
+#define E500_TLB_BITMAP 4
 
 struct tlbe_ref {
 	pfn_t pfn;
@@ -82,6 +84,9 @@ struct kvmppc_vcpu_e500 {
 	struct page **shared_tlb_pages;
 	int num_shared_tlb_pages;
 
+	u64 *g2h_tlb1_map;
+	unsigned int *h2g_tlb1_rmap;
+
 #ifdef CONFIG_KVM_E500
 	u32 pid[E500_PID_NUM];
 
diff --git a/arch/powerpc/kvm/e500_tlb.c b/arch/powerpc/kvm/e500_tlb.c
index 9925fc6..c8ce51d 100644
--- a/arch/powerpc/kvm/e500_tlb.c
+++ b/arch/powerpc/kvm/e500_tlb.c
@@ -2,6 +2,7 @@
  * Copyright (C) 2008-2011 Freescale Semiconductor, Inc. All rights reserved.
  *
  * Author: Yu Liu, yu.liu@freescale.com
+ *         Ashish Kalra, ashish.kalra@freescale.com
  *
  * Description:
  * This file is based on arch/powerpc/kvm/44x_tlb.c,
@@ -175,8 +176,28 @@ static void inval_gtlbe_on_host(struct kvmppc_vcpu_e500 *vcpu_e500,
 	struct kvm_book3e_206_tlb_entry *gtlbe =
 		get_entry(vcpu_e500, tlbsel, esel);
 
-	if (tlbsel == 1) {
-		kvmppc_e500_tlbil_all(vcpu_e500);
+	if (tlbsel == 1 &&
+	    vcpu_e500->gtlb_priv[1][esel].ref.flags & E500_TLB_BITMAP) {
+		u64 tmp = vcpu_e500->g2h_tlb1_map[esel];
+		int hw_tlb_indx;
+		unsigned long flags;
+
+		local_irq_save(flags);
+		while (tmp) {
+			hw_tlb_indx = __ilog2_u64(tmp & -tmp);
+			mtspr(SPRN_MAS0,
+			      MAS0_TLBSEL(1) |
+			      MAS0_ESEL(to_htlb1_esel(hw_tlb_indx)));
+			mtspr(SPRN_MAS1, 0);
+			asm volatile("tlbwe");
+			vcpu_e500->h2g_tlb1_rmap[hw_tlb_indx] = 0;
+			tmp &= tmp - 1;
+		}
+		mb();
+		vcpu_e500->g2h_tlb1_map[esel] = 0;
+		vcpu_e500->gtlb_priv[1][esel].ref.flags &= ~E500_TLB_BITMAP;
+		local_irq_restore(flags);
+
 		return;
 	}
 
@@ -282,6 +303,16 @@ static inline void kvmppc_e500_ref_release(struct tlbe_ref *ref)
 	}
 }
 
+static void clear_tlb1_bitmap(struct kvmppc_vcpu_e500 *vcpu_e500)
+{
+	if (vcpu_e500->g2h_tlb1_map)
+		memset(vcpu_e500->g2h_tlb1_map,
+		       sizeof(u64) * vcpu_e500->gtlb_params[1].entries, 0);
+	if (vcpu_e500->h2g_tlb1_rmap)
+		memset(vcpu_e500->h2g_tlb1_rmap,
+		       sizeof(unsigned int) * host_tlb_params[1].entries, 0);
+}
+
 static void clear_tlb_privs(struct kvmppc_vcpu_e500 *vcpu_e500)
 {
 	int tlbsel = 0;
@@ -511,7 +542,7 @@ static void kvmppc_e500_tlb0_map(struct kvmppc_vcpu_e500 *vcpu_e500,
 /* XXX for both one-one and one-to-many , for now use TLB1 */
 static int kvmppc_e500_tlb1_map(struct kvmppc_vcpu_e500 *vcpu_e500,
 		u64 gvaddr, gfn_t gfn, struct kvm_book3e_206_tlb_entry *gtlbe,
-		struct kvm_book3e_206_tlb_entry *stlbe)
+		struct kvm_book3e_206_tlb_entry *stlbe, int esel)
 {
 	struct tlbe_ref *ref;
 	unsigned int victim;
@@ -524,6 +555,14 @@ static int kvmppc_e500_tlb1_map(struct kvmppc_vcpu_e500 *vcpu_e500,
 	ref = &vcpu_e500->tlb_refs[1][victim];
 	kvmppc_e500_shadow_map(vcpu_e500, gvaddr, gfn, gtlbe, 1, stlbe, ref);
 
+	vcpu_e500->g2h_tlb1_map[esel] |= (u64)1 << victim;
+	vcpu_e500->gtlb_priv[1][esel].ref.flags |= E500_TLB_BITMAP;
+	if (vcpu_e500->h2g_tlb1_rmap[victim]) {
+		unsigned int idx = vcpu_e500->h2g_tlb1_rmap[victim];
+		vcpu_e500->g2h_tlb1_map[idx] &= ~(1ULL << victim);
+	}
+	vcpu_e500->h2g_tlb1_rmap[victim] = esel;
+
 	return victim;
 }
 
@@ -728,7 +767,7 @@ int kvmppc_e500_emul_tlbwe(struct kvm_vcpu *vcpu)
 			 * are mapped on the fly. */
 			stlbsel = 1;
 			sesel = kvmppc_e500_tlb1_map(vcpu_e500, eaddr,
-				    raddr >> PAGE_SHIFT, gtlbe, &stlbe);
+				    raddr >> PAGE_SHIFT, gtlbe, &stlbe, esel);
 			break;
 
 		default:
@@ -856,7 +895,7 @@ void kvmppc_mmu_map(struct kvm_vcpu *vcpu, u64 eaddr, gpa_t gpaddr,
 
 		stlbsel = 1;
 		sesel = kvmppc_e500_tlb1_map(vcpu_e500, eaddr, gfn,
-					     gtlbe, &stlbe);
+					     gtlbe, &stlbe, esel);
 		break;
 	}
 
@@ -872,6 +911,9 @@ static void free_gtlb(struct kvmppc_vcpu_e500 *vcpu_e500)
 {
 	int i;
 
+	clear_tlb1_bitmap(vcpu_e500);
+	kfree(vcpu_e500->g2h_tlb1_map);
+
 	clear_tlb_refs(vcpu_e500);
 	kfree(vcpu_e500->gtlb_priv[0]);
 	kfree(vcpu_e500->gtlb_priv[1]);
@@ -932,6 +974,7 @@ int kvm_vcpu_ioctl_config_tlb(struct kvm_vcpu *vcpu,
 	char *virt;
 	struct page **pages;
 	struct tlbe_priv *privs[2] = {};
+	u64 *g2h_bitmap = NULL;
 	size_t array_len;
 	u32 sets;
 	int num_pages, ret, i;
@@ -993,10 +1036,16 @@ int kvm_vcpu_ioctl_config_tlb(struct kvm_vcpu *vcpu,
 	if (!privs[0] || !privs[1])
 		goto err_put_page;
 
+	g2h_bitmap = kzalloc(sizeof(u64) * params.tlb_sizes[1],
+	                     GFP_KERNEL);
+	if (!g2h_bitmap)
+		goto err_put_page;
+
 	free_gtlb(vcpu_e500);
 
 	vcpu_e500->gtlb_priv[0] = privs[0];
 	vcpu_e500->gtlb_priv[1] = privs[1];
+	vcpu_e500->g2h_tlb1_map = g2h_bitmap;
 
 	vcpu_e500->gtlb_arch = (struct kvm_book3e_206_tlb_entry *)
 		(virt + (cfg->array & (PAGE_SIZE - 1)));
@@ -1129,6 +1178,18 @@ int kvmppc_e500_tlb_init(struct kvmppc_vcpu_e500 *vcpu_e500)
 	if (!vcpu_e500->gtlb_priv[1])
 		goto err;
 
+	vcpu_e500->g2h_tlb1_map = kzalloc(sizeof(unsigned int) *
+					  vcpu_e500->gtlb_params[1].entries,
+					  GFP_KERNEL);
+	if (!vcpu_e500->g2h_tlb1_map)
+		goto err;
+
+	vcpu_e500->h2g_tlb1_rmap = kzalloc(sizeof(unsigned int) *
+					   host_tlb_params[1].entries,
+					   GFP_KERNEL);
+	if (!vcpu_e500->h2g_tlb1_rmap)
+		goto err;
+
 	/* Init TLB configuration register */
 	vcpu->arch.tlbcfg[0] = mfspr(SPRN_TLB0CFG) &
 			     ~(TLBnCFG_N_ENTRY | TLBnCFG_ASSOC);
@@ -1154,6 +1215,7 @@ err:
 void kvmppc_e500_tlb_uninit(struct kvmppc_vcpu_e500 *vcpu_e500)
 {
 	free_gtlb(vcpu_e500);
+	kfree(vcpu_e500->h2g_tlb1_rmap);
 	kfree(vcpu_e500->tlb_refs[0]);
 	kfree(vcpu_e500->tlb_refs[1]);
 }
-- 
1.6.0.2