From 71ee8e34fe26252b11668a95708783ec9c58cbda Mon Sep 17 00:00:00 2001 From: Alexander Graf Date: Thu, 29 Jul 2010 14:48:02 +0200 Subject: [PATCH] KVM: PPC: Introduce branch patching helper We will need to patch several instruction streams over to a different code path, so we need a way to patch a single instruction with a branch somewhere else. This patch adds a helper to facilitate this patching. Signed-off-by: Alexander Graf Signed-off-by: Avi Kivity --- arch/powerpc/kernel/kvm.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/arch/powerpc/kernel/kvm.c b/arch/powerpc/kernel/kvm.c index 926f93fd722d..239a70d750a2 100644 --- a/arch/powerpc/kernel/kvm.c +++ b/arch/powerpc/kernel/kvm.c @@ -107,6 +107,20 @@ static void kvm_patch_ins_nop(u32 *inst) kvm_patch_ins(inst, KVM_INST_NOP); } +static void kvm_patch_ins_b(u32 *inst, int addr) +{ +#ifdef CONFIG_RELOCATABLE + /* On relocatable kernels interrupts handlers and our code + can be in different regions, so we don't patch them */ + + extern u32 __end_interrupts; + if ((ulong)inst < (ulong)&__end_interrupts) + return; +#endif + + kvm_patch_ins(inst, KVM_INST_B | (addr & KVM_INST_B_MASK)); +} + static u32 *kvm_alloc(int len) { u32 *p;