KVM: PPC: Add feature bitmap for magic page
We will soon add SR PV support to the shared page, so we need some
infrastructure that allows the guest to query for features KVM exports.
This patch adds a second return value to the magic mapping that
indicated to the guest which features are available.
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/arch/powerpc/include/asm/kvm_para.h b/arch/powerpc/include/asm/kvm_para.h
index 7438ab3..43c1b22 100644
--- a/arch/powerpc/include/asm/kvm_para.h
+++ b/arch/powerpc/include/asm/kvm_para.h
@@ -47,6 +47,8 @@
#define KVM_FEATURE_MAGIC_PAGE 1
+#define KVM_MAGIC_FEAT_SR (1 << 0)
+
#ifdef __KERNEL__
#ifdef CONFIG_KVM_GUEST
diff --git a/arch/powerpc/kernel/kvm.c b/arch/powerpc/kernel/kvm.c
index d3a2cc5..226882f 100644
--- a/arch/powerpc/kernel/kvm.c
+++ b/arch/powerpc/kernel/kvm.c
@@ -266,12 +266,20 @@
static void kvm_map_magic_page(void *data)
{
- kvm_hypercall2(KVM_HC_PPC_MAP_MAGIC_PAGE,
- KVM_MAGIC_PAGE, /* Physical Address */
- KVM_MAGIC_PAGE); /* Effective Address */
+ u32 *features = data;
+
+ ulong in[8];
+ ulong out[8];
+
+ in[0] = KVM_MAGIC_PAGE;
+ in[1] = KVM_MAGIC_PAGE;
+
+ kvm_hypercall(in, out, HC_VENDOR_KVM | KVM_HC_PPC_MAP_MAGIC_PAGE);
+
+ *features = out[0];
}
-static void kvm_check_ins(u32 *inst)
+static void kvm_check_ins(u32 *inst, u32 features)
{
u32 _inst = *inst;
u32 inst_no_rt = _inst & ~KVM_MASK_RT;
@@ -367,9 +375,10 @@
u32 *p;
u32 *start, *end;
u32 tmp;
+ u32 features;
/* Tell the host to map the magic page to -4096 on all CPUs */
- on_each_cpu(kvm_map_magic_page, NULL, 1);
+ on_each_cpu(kvm_map_magic_page, &features, 1);
/* Quick self-test to see if the mapping works */
if (__get_user(tmp, (u32*)KVM_MAGIC_PAGE)) {
@@ -382,7 +391,7 @@
end = (void*)_etext;
for (p = start; p < end; p++)
- kvm_check_ins(p);
+ kvm_check_ins(p, features);
printk(KERN_INFO "KVM: Live patching for a fast VM %s\n",
kvm_patching_worked ? "worked" : "failed");
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 6a53a3f..496d7a5 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -66,6 +66,8 @@
vcpu->arch.magic_page_pa = param1;
vcpu->arch.magic_page_ea = param2;
+ r2 = 0;
+
r = HC_EV_SUCCESS;
break;
}
@@ -76,13 +78,14 @@
#endif
/* Second return value is in r4 */
- kvmppc_set_gpr(vcpu, 4, r2);
break;
default:
r = HC_EV_UNIMPLEMENTED;
break;
}
+ kvmppc_set_gpr(vcpu, 4, r2);
+
return r;
}