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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>
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parent
ad0873763a
commit
8b6db3bc96
3 changed files with 48 additions and 32 deletions
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@ -60,6 +60,13 @@ struct kvmppc_sid_map {
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#define SID_MAP_NUM (1 << SID_MAP_BITS)
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#define SID_MAP_MASK (SID_MAP_NUM - 1)
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#ifdef CONFIG_PPC_BOOK3S_64
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#define SID_CONTEXTS 1
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#else
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#define SID_CONTEXTS 128
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#define VSID_POOL_SIZE (SID_CONTEXTS * 16)
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#endif
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struct kvmppc_vcpu_book3s {
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struct kvm_vcpu vcpu;
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struct kvmppc_book3s_shadow_vcpu *shadow_vcpu;
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@ -78,10 +85,14 @@ struct kvmppc_vcpu_book3s {
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u64 sdr1;
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u64 hior;
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u64 msr_mask;
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u64 vsid_first;
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u64 vsid_next;
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#ifdef CONFIG_PPC_BOOK3S_32
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u32 vsid_pool[VSID_POOL_SIZE];
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#else
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u64 vsid_first;
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u64 vsid_max;
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int context_id;
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#endif
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int context_id[SID_CONTEXTS];
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ulong prog_flags; /* flags to inject when giving a 700 trap */
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};
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@ -275,18 +275,15 @@ static struct kvmppc_sid_map *create_sid_map(struct kvm_vcpu *vcpu, u64 gvsid)
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backwards_map = !backwards_map;
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/* Uh-oh ... out of mappings. Let's flush! */
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if (vcpu_book3s->vsid_next >= vcpu_book3s->vsid_max) {
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vcpu_book3s->vsid_next = vcpu_book3s->vsid_first;
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if (vcpu_book3s->vsid_next >= VSID_POOL_SIZE) {
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vcpu_book3s->vsid_next = 0;
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memset(vcpu_book3s->sid_map, 0,
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sizeof(struct kvmppc_sid_map) * SID_MAP_NUM);
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kvmppc_mmu_pte_flush(vcpu, 0, 0);
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kvmppc_mmu_flush_segments(vcpu);
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}
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map->host_vsid = vcpu_book3s->vsid_next;
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/* Would have to be 111 to be completely aligned with the rest of
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Linux, but that is just way too little space! */
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vcpu_book3s->vsid_next+=1;
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map->host_vsid = vcpu_book3s->vsid_pool[vcpu_book3s->vsid_next];
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vcpu_book3s->vsid_next++;
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map->guest_vsid = gvsid;
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map->valid = true;
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@ -333,40 +330,38 @@ void kvmppc_mmu_flush_segments(struct kvm_vcpu *vcpu)
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void kvmppc_mmu_destroy(struct kvm_vcpu *vcpu)
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{
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int i;
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kvmppc_mmu_hpte_destroy(vcpu);
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preempt_disable();
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__destroy_context(to_book3s(vcpu)->context_id);
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for (i = 0; i < SID_CONTEXTS; i++)
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__destroy_context(to_book3s(vcpu)->context_id[i]);
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preempt_enable();
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}
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/* From mm/mmu_context_hash32.c */
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#define CTX_TO_VSID(ctx) (((ctx) * (897 * 16)) & 0xffffff)
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#define CTX_TO_VSID(c, id) ((((c) * (897 * 16)) + (id * 0x111)) & 0xffffff)
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int kvmppc_mmu_init(struct kvm_vcpu *vcpu)
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{
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struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
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int err;
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ulong sdr1;
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int i;
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int j;
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err = __init_new_context();
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if (err < 0)
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return -1;
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vcpu3s->context_id = err;
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for (i = 0; i < SID_CONTEXTS; i++) {
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err = __init_new_context();
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if (err < 0)
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goto init_fail;
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vcpu3s->context_id[i] = err;
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vcpu3s->vsid_max = CTX_TO_VSID(vcpu3s->context_id + 1) - 1;
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vcpu3s->vsid_first = CTX_TO_VSID(vcpu3s->context_id);
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/* Remember context id for this combination */
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for (j = 0; j < 16; j++)
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vcpu3s->vsid_pool[(i * 16) + j] = CTX_TO_VSID(err, j);
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}
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#if 0 /* XXX still doesn't guarantee uniqueness */
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/* We could collide with the Linux vsid space because the vsid
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* wraps around at 24 bits. We're safe if we do our own space
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* though, so let's always set the highest bit. */
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vcpu3s->vsid_max |= 0x00800000;
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vcpu3s->vsid_first |= 0x00800000;
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#endif
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BUG_ON(vcpu3s->vsid_max < vcpu3s->vsid_first);
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vcpu3s->vsid_next = vcpu3s->vsid_first;
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vcpu3s->vsid_next = 0;
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/* Remember where the HTAB is */
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asm ( "mfsdr1 %0" : "=r"(sdr1) );
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@ -376,4 +371,14 @@ int kvmppc_mmu_init(struct kvm_vcpu *vcpu)
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kvmppc_mmu_hpte_init(vcpu);
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return 0;
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init_fail:
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for (j = 0; j < i; j++) {
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if (!vcpu3s->context_id[j])
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continue;
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__destroy_context(to_book3s(vcpu)->context_id[j]);
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}
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return -1;
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}
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@ -286,7 +286,7 @@ void kvmppc_mmu_flush_segments(struct kvm_vcpu *vcpu)
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void kvmppc_mmu_destroy(struct kvm_vcpu *vcpu)
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{
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kvmppc_mmu_hpte_destroy(vcpu);
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__destroy_context(to_book3s(vcpu)->context_id);
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__destroy_context(to_book3s(vcpu)->context_id[0]);
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}
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int kvmppc_mmu_init(struct kvm_vcpu *vcpu)
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@ -297,10 +297,10 @@ int kvmppc_mmu_init(struct kvm_vcpu *vcpu)
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err = __init_new_context();
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if (err < 0)
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return -1;
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vcpu3s->context_id = err;
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vcpu3s->context_id[0] = err;
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vcpu3s->vsid_max = ((vcpu3s->context_id + 1) << USER_ESID_BITS) - 1;
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vcpu3s->vsid_first = vcpu3s->context_id << USER_ESID_BITS;
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vcpu3s->vsid_max = ((vcpu3s->context_id[0] + 1) << USER_ESID_BITS) - 1;
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vcpu3s->vsid_first = vcpu3s->context_id[0] << USER_ESID_BITS;
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vcpu3s->vsid_next = vcpu3s->vsid_first;
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kvmppc_mmu_hpte_init(vcpu);
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