Re: [PATCH 0 of 6] [RFC] Use wait queues for paging, v2

[Olaf Hering <olaf@aepfle.de>]

On Sun, Feb 26, Olaf Hering wrote:

> On Thu, Feb 23, Tim Deegan wrote:
> 
> > This is v2 of the patch I posted last week, after feedback from Andres. 
> 
> Tried this series, but processes in dom0 started to hang in D state
> when a paged guest is started. I will see if I can spot the error.

This change for patch #5 is needed, especially the first part.
Now it appears to work.

Olaf


# HG changeset patch
# Parent c3738598897f5239a72cabde676f5e86fd4c8241

diff -r c3738598897f xen/arch/x86/hvm/hvm.c
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -999,6 +999,10 @@ int hvm_vcpu_initialise(struct vcpu *v)
 
     v->arch.hvm_vcpu.inject_trap = -1;
 
+#ifdef CONFIG_X86_64
+    init_waitqueue_head(&v->arch.hvm_vcpu.mem_paging_wq);
+#endif
+
 #ifdef CONFIG_COMPAT
     rc = setup_compat_arg_xlat(v);
     if ( rc != 0 )
diff -r c3738598897f xen/arch/x86/mm/p2m.c
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -183,8 +183,8 @@ again:
             p2m_mem_paging_populate(p2m->domain, gfn);
 
         /* Wait until the pager finishes paging it in */
-        current->arch.mem_paging_gfn = gfn;
-        wait_event(current->arch.mem_paging_wq, ({
+        current->arch.hvm_vcpu.mem_paging_gfn = gfn;
+        wait_event(current->arch.hvm_vcpu.mem_paging_wq, ({
                     int done;
                     mfn = p2m->get_entry(p2m, gfn, t, a, 0, page_order);
                     done = (*t != p2m_ram_paging_in);
@@ -1190,8 +1190,8 @@ void p2m_mem_paging_resume(struct domain
         }
         /* Wake any vcpus that were waiting for this GFN */
         for_each_vcpu ( d, v )
-            if ( v->arch.mem_paging_gfn == rsp.gfn )
-                wake_up_all(&v->arch.mem_paging_wq);
+            if ( v->arch.hvm_vcpu.mem_paging_gfn == rsp.gfn )
+                wake_up_all(&v->arch.hvm_vcpu.mem_paging_wq);
     }
 }
 
diff -r c3738598897f xen/include/asm-x86/domain.h
--- a/xen/include/asm-x86/domain.h
+++ b/xen/include/asm-x86/domain.h
@@ -494,12 +494,6 @@ struct arch_vcpu
     
     struct paging_vcpu paging;
 
-#ifdef CONFIG_X86_64
-    /* Mem-paging: this vcpu is waiting for a gfn to be paged in */
-    struct waitqueue_head mem_paging_wq;
-    unsigned long mem_paging_gfn;
-#endif
-
 #ifdef CONFIG_X86_32
     /* map_domain_page() mapping cache. */
     struct mapcache_vcpu mapcache;
diff -r c3738598897f xen/include/asm-x86/hvm/vcpu.h
--- a/xen/include/asm-x86/hvm/vcpu.h
+++ b/xen/include/asm-x86/hvm/vcpu.h
@@ -170,6 +170,13 @@ struct hvm_vcpu {
     unsigned long inject_cr2;
 
     struct viridian_vcpu viridian;
+
+#ifdef CONFIG_X86_64
+    /* Mem-paging: this vcpu is waiting for a gfn to be paged in */
+    struct waitqueue_head mem_paging_wq;
+    unsigned long mem_paging_gfn;
+#endif
+
 };
 
 #endif /* __ASM_X86_HVM_VCPU_H__ */