powerpc/kvm: Fix VSID usage in 64-bit "PR" KVM

The code forgot to scramble the VSIDs the way we normally do
and was basically using the "proto VSID" directly with the MMU.

This means that in practice, KVM used random VSIDs that could
collide with segments used by other user space programs.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[agraf: simplify ppc32 case]
Signed-off-by: Alexander Graf <agraf@suse.de>

diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h
index aa795ccef2942feb73f8cf7e85bda5f7b1f47ad1..fd07f43d66224c42b367b6d911dda9ddb8a33bd4 100644 (file)
--- a/arch/powerpc/include/asm/kvm_book3s.h
+++ b/arch/powerpc/include/asm/kvm_book3s.h
@@ -81,12 +81,13 @@ struct kvmppc_vcpu_book3s {
        u64 sdr1;
        u64 hior;
        u64 msr_mask;
-       u64 vsid_next;
 #ifdef CONFIG_PPC_BOOK3S_32
        u32 vsid_pool[VSID_POOL_SIZE];
+       u32 vsid_next;
 #else
-       u64 vsid_first;
-       u64 vsid_max;
+       u64 proto_vsid_first;
+       u64 proto_vsid_max;
+       u64 proto_vsid_next;
 #endif
        int context_id[SID_CONTEXTS];
 

diff --git a/arch/powerpc/kvm/book3s_64_mmu_host.c b/arch/powerpc/kvm/book3s_64_mmu_host.c
index 6f87f39a1ac21c03d9c965223e72dab525162fd5..10fc8ec9d2a8b7e1e8e7ad8113e8dce633a5d977 100644 (file)
--- a/arch/powerpc/kvm/book3s_64_mmu_host.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_host.c
@@ -194,14 +194,14 @@ 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->proto_vsid_next == vcpu_book3s->proto_vsid_max) {
+               vcpu_book3s->proto_vsid_next = vcpu_book3s->proto_vsid_first;
                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++;
+       map->host_vsid = vsid_scramble(vcpu_book3s->proto_vsid_next++, 256M);
 
        map->guest_vsid = gvsid;
        map->valid = true;
@@ -319,9 +319,10 @@ int kvmppc_mmu_init(struct kvm_vcpu *vcpu)
                return -1;
        vcpu3s->context_id[0] = err;
 
-       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;
+       vcpu3s->proto_vsid_max = ((vcpu3s->context_id[0] + 1)
+                                 << USER_ESID_BITS) - 1;
+       vcpu3s->proto_vsid_first = vcpu3s->context_id[0] << USER_ESID_BITS;
+       vcpu3s->proto_vsid_next = vcpu3s->proto_vsid_first;
 
        kvmppc_mmu_hpte_init(vcpu);