[PATCH 3/3 - qemu-kvm stable-1.0] Fix kVM_GET_ONE_REG interface

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

Qemu-1.0 included some code to use a new get/set one register interface
to KVM which unfortunately hadn't settled, and in the end the code that
went into the kernel provides a different interface.  This updates qemu
to use the new interface.

Since the 3.3 kernel doesn't provide this interface, in either the new
or the old form, this removes the check that caused qemu to bail out
if the ioctl returns an error.  In fact we don't even print a message,
since it got printed once per vcpu, which gets a bit tedious with more
than a few vcpus.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---

This is unnecessary in qemu-master and the main qemu as both have already
been updated with the correct interfaces.

 linux-headers/asm-powerpc/kvm.h |    2 +-
 linux-headers/linux/kvm.h       |   35 +++++++++++++++++++----------------
 target-ppc/kvm.c                |   12 ++++++++----
 3 files changed, 28 insertions(+), 21 deletions(-)

diff --git a/linux-headers/asm-powerpc/kvm.h b/linux-headers/asm-powerpc/kvm.h
index fb3fddc..dea2156 100644
--- a/linux-headers/asm-powerpc/kvm.h
+++ b/linux-headers/asm-powerpc/kvm.h
@@ -327,6 +327,6 @@ struct kvm_book3e_206_tlb_params {
 	__u32 reserved[8];
 };
 
-#define KVM_ONE_REG_PPC_HIOR	KVM_ONE_REG_PPC | 0x100
+#define KVM_REG_PPC_HIOR	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0x1)
 
 #endif /* __LINUX_KVM_POWERPC_H */
diff --git a/linux-headers/linux/kvm.h b/linux-headers/linux/kvm.h
index a8761d3..8c33a57 100644
--- a/linux-headers/linux/kvm.h
+++ b/linux-headers/linux/kvm.h
@@ -654,30 +654,33 @@ struct kvm_dirty_tlb {
 
 /* Available with KVM_CAP_ONE_REG */
 
-#define KVM_ONE_REG_GENERIC		0x0000000000000000ULL
+#define KVM_REG_ARCH_MASK	0xff00000000000000ULL
+#define KVM_REG_GENERIC		0x0000000000000000ULL
 
 /*
  * Architecture specific registers are to be defined in arch headers and
  * ORed with the arch identifier.
  */
-#define KVM_ONE_REG_PPC			0x1000000000000000ULL
-#define KVM_ONE_REG_X86			0x2000000000000000ULL
-#define KVM_ONE_REG_IA64		0x3000000000000000ULL
-#define KVM_ONE_REG_ARM			0x4000000000000000ULL
-#define KVM_ONE_REG_S390		0x5000000000000000ULL
+#define KVM_REG_PPC		0x1000000000000000ULL
+#define KVM_REG_X86		0x2000000000000000ULL
+#define KVM_REG_IA64		0x3000000000000000ULL
+#define KVM_REG_ARM		0x4000000000000000ULL
+#define KVM_REG_S390		0x5000000000000000ULL
+
+#define KVM_REG_SIZE_SHIFT	52
+#define KVM_REG_SIZE_MASK	0x00f0000000000000ULL
+#define KVM_REG_SIZE_U8		0x0000000000000000ULL
+#define KVM_REG_SIZE_U16	0x0010000000000000ULL
+#define KVM_REG_SIZE_U32	0x0020000000000000ULL
+#define KVM_REG_SIZE_U64	0x0030000000000000ULL
+#define KVM_REG_SIZE_U128	0x0040000000000000ULL
+#define KVM_REG_SIZE_U256	0x0050000000000000ULL
+#define KVM_REG_SIZE_U512	0x0060000000000000ULL
+#define KVM_REG_SIZE_U1024	0x0070000000000000ULL
 
 struct kvm_one_reg {
 	__u64 id;
-	union {
-		__u8 reg8;
-		__u16 reg16;
-		__u32 reg32;
-		__u64 reg64;
-		__u8 reg128[16];
-		__u8 reg256[32];
-		__u8 reg512[64];
-		__u8 reg1024[128];
-	} u;
+	__u64 addr;
 };
 
 /*
diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
index 0410901..f7c986c 100644
--- a/target-ppc/kvm.c
+++ b/target-ppc/kvm.c
@@ -740,6 +740,7 @@ void kvmppc_set_papr(CPUState *env)
     struct kvm_one_reg reg = {};
     struct kvm_sregs sregs = {};
     int ret;
+    uint64_t hior = env->spr[SPR_HIOR];
 
     cap.cap = KVM_CAP_PPC_PAPR;
     ret = kvm_vcpu_ioctl(env, KVM_ENABLE_CAP, &cap);
@@ -755,11 +756,14 @@ void kvmppc_set_papr(CPUState *env)
      *     Once we have qdev CPUs, move HIOR to a qdev property and
      *     remove this chunk.
      */
-    reg.id = KVM_ONE_REG_PPC_HIOR;
-    reg.u.reg64 = env->spr[SPR_HIOR];
+    reg.id = KVM_REG_PPC_HIOR;
+    reg.addr = (uintptr_t)&hior;
     ret = kvm_vcpu_ioctl(env, KVM_SET_ONE_REG, &reg);
-    if (ret) {
-        goto fail;
+    if (ret && 0) {
+        fprintf(stderr, "Couldn't set HIOR. Maybe you're running an old \n"
+                        "kernel with support for HV KVM but no PAPR PR \n"
+                        "KVM in which case things will work. If they don't \n"
+                        "please update your host kernel!\n");
     }
 
     /* Set SDR1 so kernel space finds the HTAB */