KVM: ia64: Drop in SN2 replacement of fast path ITC emulation fault handler
Copy in SN2 RTC based ITC emulation for fast exit. The two versions
have the same size, so a dropin is simpler than patching the branch
instruction to hit the SN2 version.
Signed-off-by: Jes Sorensen <jes@sgi.com>
Acked-by: Xiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c
index ebbd995..4623a90 100644
--- a/arch/ia64/kvm/kvm-ia64.c
+++ b/arch/ia64/kvm/kvm-ia64.c
@@ -1671,8 +1671,37 @@
return 0;
}
+
+/*
+ * On SN2, the ITC isn't stable, so copy in fast path code to use the
+ * SN2 RTC, replacing the ITC based default verion.
+ */
+static void kvm_patch_vmm(struct kvm_vmm_info *vmm_info,
+ struct module *module)
+{
+ unsigned long new_ar, new_ar_sn2;
+ unsigned long module_base;
+
+ if (!ia64_platform_is("sn2"))
+ return;
+
+ module_base = (unsigned long)module->module_core;
+
+ new_ar = kvm_vmm_base + vmm_info->patch_mov_ar - module_base;
+ new_ar_sn2 = kvm_vmm_base + vmm_info->patch_mov_ar_sn2 - module_base;
+
+ printk(KERN_INFO "kvm: Patching ITC emulation to use SGI SN2 RTC "
+ "as source\n");
+
+ /*
+ * Copy the SN2 version of mov_ar into place. They are both
+ * the same size, so 6 bundles is sufficient (6 * 0x10).
+ */
+ memcpy((void *)new_ar, (void *)new_ar_sn2, 0x60);
+}
+
static int kvm_relocate_vmm(struct kvm_vmm_info *vmm_info,
- struct module *module)
+ struct module *module)
{
unsigned long module_base;
unsigned long vmm_size;
@@ -1694,6 +1723,7 @@
return -EFAULT;
memcpy((void *)kvm_vmm_base, (void *)module_base, vmm_size);
+ kvm_patch_vmm(vmm_info, module);
kvm_flush_icache(kvm_vmm_base, vmm_size);
/*Recalculate kvm_vmm_info based on new VMM*/