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 <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Alexander Graf 2010-07-29 14:48:02 +02:00 committed by Avi Kivity
parent 2d4f567103
commit 71ee8e34fe
1 changed files with 14 additions and 0 deletions

View File

@ -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;