KVM: PPC: e500: Track TLB1 entries with a bitmap

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>
Signed-off-by: Avi Kivity <avi@redhat.com>

2 files changed, 72 insertions, 5 deletions

diff --git a/arch/powerpc/kvm/e500.h b/arch/powerpc/kvm/e500.h
index 34cef08f1361..f4dee55ae6c7 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 9925fc6c9cfb..c8ce51d03a2f 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]);
 }