[25/26] KVM: PPC: PV wrteei

Commit Message

Alexander Graf June 25, 2010, 11:25 p.m. UTC

None

Patch

diff --git a/arch/powerpc/kernel/kvm.c b/arch/powerpc/kernel/kvm.c
index 3557bc8..85e2163 100644
--- a/arch/powerpc/kernel/kvm.c
+++ b/arch/powerpc/kernel/kvm.c
@@ -66,6 +66,9 @@ 
 #define KVM_INST_MTMSRD_L1	0x7c010164
 #define KVM_INST_MTMSR		0x7c000124
 
+#define KVM_INST_WRTEEI_0	0x7c000146
+#define KVM_INST_WRTEEI_1	0x7c008146
+
 static bool kvm_patching_worked = true;
 static char kvm_tmp[1024 * 1024];
 static int kvm_tmp_index;
@@ -200,6 +203,47 @@  static void kvm_patch_ins_mtmsr(u32 *inst, u32 rt)
 	*inst = KVM_INST_B | (distance_start & KVM_INST_B_MASK);
 }
 
+#ifdef CONFIG_BOOKE
+
+extern u32 kvm_emulate_wrteei_branch_offs;
+extern u32 kvm_emulate_wrteei_ee_offs;
+extern u32 kvm_emulate_wrteei_len;
+extern u32 kvm_emulate_wrteei[];
+
+static void kvm_patch_ins_wrteei(u32 *inst)
+{
+	u32 *p;
+	int distance_start;
+	int distance_end;
+	ulong next_inst;
+
+	p = kvm_alloc(kvm_emulate_wrteei_len * 4);
+	if (!p)
+		return;
+
+	/* Find out where we are and put everything there */
+	distance_start = (ulong)p - (ulong)inst;
+	next_inst = ((ulong)inst + 4);
+	distance_end = next_inst - (ulong)&p[kvm_emulate_wrteei_branch_offs];
+
+	/* Make sure we only write valid b instructions */
+	if (distance_start > KVM_INST_B_MAX) {
+		kvm_patching_worked = false;
+		return;
+	}
+
+	/* Modify the chunk to fit the invocation */
+	memcpy(p, kvm_emulate_wrteei, kvm_emulate_wrteei_len * 4);
+	p[kvm_emulate_wrteei_branch_offs] |= distance_end & KVM_INST_B_MASK;
+	p[kvm_emulate_wrteei_ee_offs] |= (*inst & MSR_EE);
+	flush_icache_range((ulong)p, (ulong)p + kvm_emulate_wrteei_len * 4);
+
+	/* Patch the invocation */
+	*inst = KVM_INST_B | (distance_start & KVM_INST_B_MASK);
+}
+
+#endif
+
 static void kvm_map_magic_page(void *data)
 {
 	kvm_hypercall2(KVM_HC_PPC_MAP_MAGIC_PAGE,
@@ -289,6 +333,12 @@  static void kvm_check_ins(u32 *inst)
 	}
 
 	switch (_inst) {
+#ifdef CONFIG_BOOKE
+	case KVM_INST_WRTEEI_0:
+	case KVM_INST_WRTEEI_1:
+		kvm_patch_ins_wrteei(inst);
+		break;
+#endif
 	}
 
 	flush_icache_range((ulong)inst, (ulong)inst + 4);
diff --git a/arch/powerpc/kernel/kvm_emul.S b/arch/powerpc/kernel/kvm_emul.S
index ccf5a42..b79b9de 100644
--- a/arch/powerpc/kernel/kvm_emul.S
+++ b/arch/powerpc/kernel/kvm_emul.S
@@ -194,3 +194,44 @@  kvm_emulate_mtmsr_orig_ins_offs:
 .global kvm_emulate_mtmsr_len
 kvm_emulate_mtmsr_len:
 	.long (kvm_emulate_mtmsr_end - kvm_emulate_mtmsr) / 4
+
+
+
+.global kvm_emulate_wrteei
+kvm_emulate_wrteei:
+
+	SCRATCH_SAVE
+
+	/* Fetch old MSR in r31 */
+	LL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)
+
+	/* Remove MSR_EE from old MSR */
+	li	r30, 0
+	ori	r30, r30, MSR_EE
+	andc	r31, r31, r30
+
+	/* OR new MSR_EE onto the old MSR */
+kvm_emulate_wrteei_ee:
+	ori	r31, r31, 0
+
+	/* Write new MSR value back */
+	STL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)
+
+	SCRATCH_RESTORE
+
+	/* Go back to caller */
+kvm_emulate_wrteei_branch:
+	b	.
+kvm_emulate_wrteei_end:
+
+.global kvm_emulate_wrteei_branch_offs
+kvm_emulate_wrteei_branch_offs:
+	.long (kvm_emulate_wrteei_branch - kvm_emulate_wrteei) / 4
+
+.global kvm_emulate_wrteei_ee_offs
+kvm_emulate_wrteei_ee_offs:
+	.long (kvm_emulate_wrteei_ee - kvm_emulate_wrteei) / 4
+
+.global kvm_emulate_wrteei_len
+kvm_emulate_wrteei_len:
+	.long (kvm_emulate_wrteei_end - kvm_emulate_wrteei) / 4