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authorAlexander Graf <agraf@suse.de>2010-08-15 10:04:24 +0400
committerAvi Kivity <avi@redhat.com>2010-10-24 12:52:15 +0400
commit8b6db3bc965c204db6868d4005808b4fdc9c46d7 (patch)
tree973d040d221d5fd3448c97b1c102d014fe6e6687 /arch/powerpc/kvm
parentad0873763a83e7b31ba87a85ec2027dd6a9d7b55 (diff)
downloadlinux-8b6db3bc965c204db6868d4005808b4fdc9c46d7.tar.xz
KVM: PPC: Implement correct SID mapping on Book3s_32
Up until now we were doing segment mappings wrong on Book3s_32. For Book3s_64 we were using a trick where we know that a single mmu_context gives us 16 bits of context ids. The mm system on Book3s_32 instead uses a clever algorithm to distribute VSIDs across the available range, so a context id really only gives us 16 available VSIDs. To keep at least a few guest processes in the SID shadow, let's map a number of contexts that we can use as VSID pool. This makes the code be actually correct and shouldn't hurt performance too much. Signed-off-by: Alexander Graf <agraf@suse.de>
Diffstat (limited to 'arch/powerpc/kvm')
-rw-r--r--arch/powerpc/kvm/book3s_32_mmu_host.c57
-rw-r--r--arch/powerpc/kvm/book3s_64_mmu_host.c8
2 files changed, 35 insertions, 30 deletions
diff --git a/arch/powerpc/kvm/book3s_32_mmu_host.c b/arch/powerpc/kvm/book3s_32_mmu_host.c
index 57dddeb23b9b..9fecbfbce773 100644
--- a/arch/powerpc/kvm/book3s_32_mmu_host.c
+++ b/arch/powerpc/kvm/book3s_32_mmu_host.c
@@ -275,18 +275,15 @@ static struct kvmppc_sid_map *create_sid_map(struct kvm_vcpu *vcpu, u64 gvsid)
backwards_map = !backwards_map;
/* Uh-oh ... out of mappings. Let's flush! */
- if (vcpu_book3s->vsid_next >= vcpu_book3s->vsid_max) {
- vcpu_book3s->vsid_next = vcpu_book3s->vsid_first;
+ if (vcpu_book3s->vsid_next >= VSID_POOL_SIZE) {
+ vcpu_book3s->vsid_next = 0;
memset(vcpu_book3s->sid_map, 0,
sizeof(struct kvmppc_sid_map) * SID_MAP_NUM);
kvmppc_mmu_pte_flush(vcpu, 0, 0);
kvmppc_mmu_flush_segments(vcpu);
}
- map->host_vsid = vcpu_book3s->vsid_next;
-
- /* Would have to be 111 to be completely aligned with the rest of
- Linux, but that is just way too little space! */
- vcpu_book3s->vsid_next+=1;
+ map->host_vsid = vcpu_book3s->vsid_pool[vcpu_book3s->vsid_next];
+ vcpu_book3s->vsid_next++;
map->guest_vsid = gvsid;
map->valid = true;
@@ -333,40 +330,38 @@ void kvmppc_mmu_flush_segments(struct kvm_vcpu *vcpu)
void kvmppc_mmu_destroy(struct kvm_vcpu *vcpu)
{
+ int i;
+
kvmppc_mmu_hpte_destroy(vcpu);
preempt_disable();
- __destroy_context(to_book3s(vcpu)->context_id);
+ for (i = 0; i < SID_CONTEXTS; i++)
+ __destroy_context(to_book3s(vcpu)->context_id[i]);
preempt_enable();
}
/* From mm/mmu_context_hash32.c */
-#define CTX_TO_VSID(ctx) (((ctx) * (897 * 16)) & 0xffffff)
+#define CTX_TO_VSID(c, id) ((((c) * (897 * 16)) + (id * 0x111)) & 0xffffff)
int kvmppc_mmu_init(struct kvm_vcpu *vcpu)
{
struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
int err;
ulong sdr1;
+ int i;
+ int j;
- err = __init_new_context();
- if (err < 0)
- return -1;
- vcpu3s->context_id = err;
-
- vcpu3s->vsid_max = CTX_TO_VSID(vcpu3s->context_id + 1) - 1;
- vcpu3s->vsid_first = CTX_TO_VSID(vcpu3s->context_id);
-
-#if 0 /* XXX still doesn't guarantee uniqueness */
- /* We could collide with the Linux vsid space because the vsid
- * wraps around at 24 bits. We're safe if we do our own space
- * though, so let's always set the highest bit. */
+ for (i = 0; i < SID_CONTEXTS; i++) {
+ err = __init_new_context();
+ if (err < 0)
+ goto init_fail;
+ vcpu3s->context_id[i] = err;
- vcpu3s->vsid_max |= 0x00800000;
- vcpu3s->vsid_first |= 0x00800000;
-#endif
- BUG_ON(vcpu3s->vsid_max < vcpu3s->vsid_first);
+ /* Remember context id for this combination */
+ for (j = 0; j < 16; j++)
+ vcpu3s->vsid_pool[(i * 16) + j] = CTX_TO_VSID(err, j);
+ }
- vcpu3s->vsid_next = vcpu3s->vsid_first;
+ vcpu3s->vsid_next = 0;
/* Remember where the HTAB is */
asm ( "mfsdr1 %0" : "=r"(sdr1) );
@@ -376,4 +371,14 @@ int kvmppc_mmu_init(struct kvm_vcpu *vcpu)
kvmppc_mmu_hpte_init(vcpu);
return 0;
+
+init_fail:
+ for (j = 0; j < i; j++) {
+ if (!vcpu3s->context_id[j])
+ continue;
+
+ __destroy_context(to_book3s(vcpu)->context_id[j]);
+ }
+
+ return -1;
}
diff --git a/arch/powerpc/kvm/book3s_64_mmu_host.c b/arch/powerpc/kvm/book3s_64_mmu_host.c
index 4040c8d16ad5..fa2f08434ba5 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_host.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_host.c
@@ -286,7 +286,7 @@ void kvmppc_mmu_flush_segments(struct kvm_vcpu *vcpu)
void kvmppc_mmu_destroy(struct kvm_vcpu *vcpu)
{
kvmppc_mmu_hpte_destroy(vcpu);
- __destroy_context(to_book3s(vcpu)->context_id);
+ __destroy_context(to_book3s(vcpu)->context_id[0]);
}
int kvmppc_mmu_init(struct kvm_vcpu *vcpu)
@@ -297,10 +297,10 @@ int kvmppc_mmu_init(struct kvm_vcpu *vcpu)
err = __init_new_context();
if (err < 0)
return -1;
- vcpu3s->context_id = err;
+ vcpu3s->context_id[0] = err;
- vcpu3s->vsid_max = ((vcpu3s->context_id + 1) << USER_ESID_BITS) - 1;
- vcpu3s->vsid_first = vcpu3s->context_id << USER_ESID_BITS;
+ vcpu3s->vsid_max = ((vcpu3s->context_id[0] + 1) << USER_ESID_BITS) - 1;
+ vcpu3s->vsid_first = vcpu3s->context_id[0] << USER_ESID_BITS;
vcpu3s->vsid_next = vcpu3s->vsid_first;
kvmppc_mmu_hpte_init(vcpu);