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authorAlexander Graf <agraf@suse.de>2011-08-08 16:07:16 +0200
committerAvi Kivity <avi@redhat.com>2011-09-25 19:52:20 +0300
commit317a8fa304f8ba3cd8b67b0f5f38e366e8c3cf1d (patch)
tree874c27833a8dbaddce52f5313c7c6af41143369d
parent9432ba6015371f186926cd62e2395718217a17a1 (diff)
KVM: PPC: Check privilege level on SPRs
We have 3 privilege levels: problem state, supervisor state and hypervisor state. Each of them can access different SPRs, so we need to check on every SPR if it's accessible in the respective mode. Signed-off-by: Alexander Graf <agraf@suse.de>
-rw-r--r--arch/powerpc/kvm/book3s_emulate.c25
1 files changed, 25 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/book3s_emulate.c b/arch/powerpc/kvm/book3s_emulate.c
index 466846557089..bf0ddcd98bcc 100644
--- a/arch/powerpc/kvm/book3s_emulate.c
+++ b/arch/powerpc/kvm/book3s_emulate.c
@@ -63,6 +63,25 @@
* function pointers, so let's just disable the define. */
#undef mfsrin
+enum priv_level {
+ PRIV_PROBLEM = 0,
+ PRIV_SUPER = 1,
+ PRIV_HYPER = 2,
+};
+
+static bool spr_allowed(struct kvm_vcpu *vcpu, enum priv_level level)
+{
+ /* PAPR VMs only access supervisor SPRs */
+ if (vcpu->arch.papr_enabled && (level > PRIV_SUPER))
+ return false;
+
+ /* Limit user space to its own small SPR set */
+ if ((vcpu->arch.shared->msr & MSR_PR) && level > PRIV_PROBLEM)
+ return false;
+
+ return true;
+}
+
int kvmppc_core_emulate_op(struct kvm_run *run, struct kvm_vcpu *vcpu,
unsigned int inst, int *advance)
{
@@ -296,6 +315,8 @@ int kvmppc_core_emulate_mtspr(struct kvm_vcpu *vcpu, int sprn, int rs)
switch (sprn) {
case SPRN_SDR1:
+ if (!spr_allowed(vcpu, PRIV_HYPER))
+ goto unprivileged;
to_book3s(vcpu)->sdr1 = spr_val;
break;
case SPRN_DSISR:
@@ -390,6 +411,7 @@ int kvmppc_core_emulate_mtspr(struct kvm_vcpu *vcpu, int sprn, int rs)
case SPRN_PMC4_GEKKO:
case SPRN_WPAR_GEKKO:
break;
+unprivileged:
default:
printk(KERN_INFO "KVM: invalid SPR write: %d\n", sprn);
#ifndef DEBUG_SPR
@@ -421,6 +443,8 @@ int kvmppc_core_emulate_mfspr(struct kvm_vcpu *vcpu, int sprn, int rt)
break;
}
case SPRN_SDR1:
+ if (!spr_allowed(vcpu, PRIV_HYPER))
+ goto unprivileged;
kvmppc_set_gpr(vcpu, rt, to_book3s(vcpu)->sdr1);
break;
case SPRN_DSISR:
@@ -476,6 +500,7 @@ int kvmppc_core_emulate_mfspr(struct kvm_vcpu *vcpu, int sprn, int rt)
kvmppc_set_gpr(vcpu, rt, 0);
break;
default:
+unprivileged:
printk(KERN_INFO "KVM: invalid SPR read: %d\n", sprn);
#ifndef DEBUG_SPR
emulated = EMULATE_FAIL;