From 8b6db3bc965c204db6868d4005808b4fdc9c46d7 Mon Sep 17 00:00:00 2001 From: Alexander Graf Date: Sun, 15 Aug 2010 08:04:24 +0200 Subject: [PATCH] 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 --- arch/powerpc/include/asm/kvm_book3s.h | 15 +++++++-- arch/powerpc/kvm/book3s_32_mmu_host.c | 57 +++++++++++++++++++---------------- arch/powerpc/kvm/book3s_64_mmu_host.c | 8 ++--- 3 files changed, 48 insertions(+), 32 deletions(-) diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h index be8aac2..d62e703f 100644 --- a/arch/powerpc/include/asm/kvm_book3s.h +++ b/arch/powerpc/include/asm/kvm_book3s.h @@ -60,6 +60,13 @@ struct kvmppc_sid_map { #define SID_MAP_NUM (1 << SID_MAP_BITS) #define SID_MAP_MASK (SID_MAP_NUM - 1) +#ifdef CONFIG_PPC_BOOK3S_64 +#define SID_CONTEXTS 1 +#else +#define SID_CONTEXTS 128 +#define VSID_POOL_SIZE (SID_CONTEXTS * 16) +#endif + struct kvmppc_vcpu_book3s { struct kvm_vcpu vcpu; struct kvmppc_book3s_shadow_vcpu *shadow_vcpu; @@ -78,10 +85,14 @@ struct kvmppc_vcpu_book3s { u64 sdr1; u64 hior; u64 msr_mask; - u64 vsid_first; u64 vsid_next; +#ifdef CONFIG_PPC_BOOK3S_32 + u32 vsid_pool[VSID_POOL_SIZE]; +#else + u64 vsid_first; u64 vsid_max; - int context_id; +#endif + int context_id[SID_CONTEXTS]; ulong prog_flags; /* flags to inject when giving a 700 trap */ }; diff --git a/arch/powerpc/kvm/book3s_32_mmu_host.c b/arch/powerpc/kvm/book3s_32_mmu_host.c index 57dddeb..9fecbfb 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 4040c8d..fa2f084 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); -- 2.7.4