[RFC Patch v2 01/16] xen: introduce new hypercall to reset vcpu

[Wen Congyang <wency@cn.fujitsu.com>]

In colo mode, SVM is running, and it will create pagetable, use gdt...
When we do a new checkpoint, we may need to rollback all this operations.
This new hypercall will do this.

Signed-off-by: Ye Wei <wei.ye1987@gmail.com>
Signed-off-by: Jiang Yunhong <yunhong.jiang@intel.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
---
 xen/arch/x86/domain.c       |   57 +++++++++++++++++++++++++++++++++++++++++++
 xen/arch/x86/x86_64/entry.S |    4 +++
 xen/include/public/xen.h    |    1 +
 3 files changed, 62 insertions(+), 0 deletions(-)

diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index 874742c..709f77f 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -1930,6 +1930,63 @@ int domain_relinquish_resources(struct domain *d)
     return 0;
 }
 
+int do_reset_vcpu_op(unsigned long domid)
+{
+    struct vcpu *v;
+    struct domain *d;
+    int ret;
+
+    if ( domid == DOMID_SELF )
+        /* We can't destroy outself pagetables */
+        return -EINVAL;
+
+    if ( (d = rcu_lock_domain_by_id(domid)) == NULL )
+        return -EINVAL;
+
+    BUG_ON(!cpumask_empty(d->domain_dirty_cpumask));
+    domain_pause(d);
+
+    if ( d->arch.relmem == RELMEM_not_started )
+    {
+        for_each_vcpu ( d, v )
+        {
+            /* Drop the in-use references to page-table bases. */
+            ret = vcpu_destroy_pagetables(v);
+            if ( ret )
+                return ret;
+
+            unmap_vcpu_info(v);
+            v->is_initialised = 0;
+        }
+
+        if ( !is_hvm_domain(d) )
+        {
+            for_each_vcpu ( d, v )
+            {
+                /*
+                 * Relinquish GDT mappings. No need for explicit unmapping of the
+                 * LDT as it automatically gets squashed with the guest mappings.
+                 */
+                destroy_gdt(v);
+            }
+
+            if ( d->arch.pv_domain.pirq_eoi_map != NULL )
+            {
+                unmap_domain_page_global(d->arch.pv_domain.pirq_eoi_map);
+                put_page_and_type(
+                    mfn_to_page(d->arch.pv_domain.pirq_eoi_map_mfn));
+                d->arch.pv_domain.pirq_eoi_map = NULL;
+                d->arch.pv_domain.auto_unmask = 0;
+            }
+        }
+    }
+
+    domain_unpause(d);
+    rcu_unlock_domain(d);
+
+    return 0;
+}
+
 void arch_dump_domain_info(struct domain *d)
 {
     paging_dump_domain_info(d);
diff --git a/xen/arch/x86/x86_64/entry.S b/xen/arch/x86/x86_64/entry.S
index 5beeccb..0e4dde4 100644
--- a/xen/arch/x86/x86_64/entry.S
+++ b/xen/arch/x86/x86_64/entry.S
@@ -762,6 +762,8 @@ ENTRY(hypercall_table)
         .quad do_domctl
         .quad do_kexec_op
         .quad do_tmem_op
+        .quad do_ni_hypercall       /* reserved for XenClient */
+        .quad do_reset_vcpu_op      /* 40 */
         .rept __HYPERVISOR_arch_0-((.-hypercall_table)/8)
         .quad do_ni_hypercall
         .endr
@@ -810,6 +812,8 @@ ENTRY(hypercall_args_table)
         .byte 1 /* do_domctl            */
         .byte 2 /* do_kexec             */
         .byte 1 /* do_tmem_op           */
+        .byte 0 /* do_ni_hypercall      */
+        .byte 1 /* do_reset_vcpu_op     */  /* 40 */
         .rept __HYPERVISOR_arch_0-(.-hypercall_args_table)
         .byte 0 /* do_ni_hypercall      */
         .endr
diff --git a/xen/include/public/xen.h b/xen/include/public/xen.h
index 3cab74f..696f4a3 100644
--- a/xen/include/public/xen.h
+++ b/xen/include/public/xen.h
@@ -101,6 +101,7 @@ DEFINE_XEN_GUEST_HANDLE(xen_ulong_t);
 #define __HYPERVISOR_kexec_op             37
 #define __HYPERVISOR_tmem_op              38
 #define __HYPERVISOR_xc_reserved_op       39 /* reserved for XenClient */
+#define __HYPERVISOR_reset_vcpu_op        40
 
 /* Architecture-specific hypercall definitions. */
 #define __HYPERVISOR_arch_0               48
-- 
1.7.4