Attachment 295729 Details for Bug 425411 – PATCH 3 to fix 32-on-64 save/restore issue

[patch] PATCH 3 to fix 32-on-64 save/restore issue

compat.patch (text/plain), 9.99 KB, created by Chris Lalancette on 2008-02-24 03:41:49 UTC

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Creator: Chris Lalancette

Created: 2008-02-24 03:41:49 UTC

Size: 9.99 KB

patch

obsolete

>diff -r 2a3111016f88 tools/libxc/xc_domain_restore.c
>--- a/tools/libxc/xc_domain_restore.c	Mon Feb 11 15:59:49 2008 +0000
>+++ b/tools/libxc/xc_domain_restore.c	Tue Feb 12 17:16:48 2008 +0000
>@@ -251,7 +251,7 @@ static xen_pfn_t *load_p2m_frame_list(
> 
>     /* Now that we know the guest's word-size, can safely allocate 
>      * the p2m frame list */
>-    if ( (p2m_frame_list = malloc(P2M_FL_SIZE)) == NULL )
>+    if ( (p2m_frame_list = malloc(P2M_TOOLS_FL_SIZE)) == NULL )
>     {
>         ERROR("Couldn't allocate p2m_frame_list array");
>         return NULL;
>@@ -1040,7 +1040,7 @@ int xc_domain_restore(int xc_handle, int
>             SET_FIELD(&ctxt, gdt_frames[j], p2m[pfn]);
>         }
>         /* Uncanonicalise the page table base pointer. */
>-        pfn = xen_cr3_to_pfn(GET_FIELD(&ctxt, ctrlreg[3]));
>+        pfn = UNFOLD_CR3(GET_FIELD(&ctxt, ctrlreg[3]));
> 
>         if ( pfn >= p2m_size )
>         {
>@@ -1057,12 +1057,12 @@ int xc_domain_restore(int xc_handle, int
>                   (unsigned long)pt_levels<<XEN_DOMCTL_PFINFO_LTAB_SHIFT);
>             goto out;
>         }
>-        SET_FIELD(&ctxt, ctrlreg[3], xen_pfn_to_cr3(p2m[pfn]));
>+        SET_FIELD(&ctxt, ctrlreg[3], FOLD_CR3(p2m[pfn]));
> 
>         /* Guest pagetable (x86/64) stored in otherwise-unused CR1. */
>         if ( (pt_levels == 4) && (ctxt.x64.ctrlreg[1] & 1) )
>         {
>-            pfn = xen_cr3_to_pfn(ctxt.x64.ctrlreg[1] & ~1);
>+            pfn = UNFOLD_CR3(ctxt.x64.ctrlreg[1] & ~1);
>             if ( pfn >= p2m_size )
>             {
>                 ERROR("User PT base is bad: pfn=%lu p2m_size=%lu",
>@@ -1077,7 +1077,7 @@ int xc_domain_restore(int xc_handle, int
>                       (unsigned long)pt_levels<<XEN_DOMCTL_PFINFO_LTAB_SHIFT);
>                 goto out;
>             }
>-            ctxt.x64.ctrlreg[1] = xen_pfn_to_cr3(p2m[pfn]);
>+            ctxt.x64.ctrlreg[1] = FOLD_CR3(p2m[pfn]);
>         }
>         domctl.cmd = XEN_DOMCTL_setvcpucontext;
>         domctl.domain = (domid_t)dom;
>@@ -1158,7 +1158,7 @@ int xc_domain_restore(int xc_handle, int
>     if ( guest_width > sizeof (xen_pfn_t) )
>         for ( i = p2m_size - 1; i >= 0; i-- )
>             ((uint64_t *)p2m)[i] = p2m[i];
>-    else if ( guest_width > sizeof (xen_pfn_t) )
>+    else if ( guest_width < sizeof (xen_pfn_t) )
>         for ( i = 0; i < p2m_size; i++ )   
>             ((uint32_t *)p2m)[i] = p2m[i];
> 
>diff -r 2a3111016f88 tools/libxc/xc_domain_save.c
>--- a/tools/libxc/xc_domain_save.c	Mon Feb 11 15:59:49 2008 +0000
>+++ b/tools/libxc/xc_domain_save.c	Tue Feb 12 17:19:17 2008 +0000
>@@ -61,10 +61,11 @@ unsigned int guest_width;
> 
> #define mfn_to_pfn(_mfn)  (live_m2p[(_mfn)])
> 
>-#define pfn_to_mfn(_pfn)                                \
>-  ((xen_pfn_t) ((guest_width==8)                       \
>-                ? (((uint64_t *)live_p2m)[(_pfn)])      \
>-                : (((uint32_t *)live_p2m)[(_pfn)])))
>+#define pfn_to_mfn(_pfn)                                            \
>+  ((xen_pfn_t) ((guest_width==8)                                    \
>+                ? (((uint64_t *)live_p2m)[(_pfn)])                  \
>+                : ((((uint32_t *)live_p2m)[(_pfn)]) == 0xffffffffU  \
>+                   ? (-1UL) : (((uint32_t *)live_p2m)[(_pfn)]))))
> 
> /*
>  * Returns TRUE if the given machine frame number has a unique mapping
>@@ -496,10 +497,9 @@ static int canonicalize_pagetable(unsign
>         xen_start = L3_PAGETABLE_ENTRIES_PAE;
> 
>     /*
>-    ** in PAE only the L2 mapping the top 1GB contains Xen mappings.
>-    ** We can spot this by looking for the guest linear mapping which
>-    ** Xen always ensures is present in that L2. Guests must ensure
>-    ** that this check will fail for other L2s.
>+    ** In PAE only the L2 mapping the top 1GB contains Xen mappings.
>+    ** We can spot this by looking for the guest's mappingof the m2p.
>+    ** Guests must ensure that this check will fail for other L2s.
>     */
>     if ( (pt_levels == 3) && (type == XEN_DOMCTL_PFINFO_L2TAB) )
>     {
>@@ -555,7 +555,13 @@ static int canonicalize_pagetable(unsign
>                 /* This will happen if the type info is stale which
>                    is quite feasible under live migration */
>                 pfn  = 0;  /* zap it - we'll retransmit this page later */
>-                race = 1;  /* inform the caller of race; fatal if !live */ 
>+                /* XXX: We can't spot Xen mappings in compat-mode L2es 
>+                 * from 64-bit tools, but the only thing in them is the
>+                 * compat m2p, so we quietly zap them.  This doesn't
>+                 * count as a race, so don't report it. */
>+                if ( !(type == XEN_DOMCTL_PFINFO_L2TAB 
>+                       && sizeof (unsigned long) > guest_width) )
>+                     race = 1;  /* inform the caller; fatal if !live */ 
>             }
>             else
>                 pfn = mfn_to_pfn(mfn);
>@@ -690,7 +696,7 @@ static xen_pfn_t *map_and_save_p2m_table
>             else
>                 p2m_frame_list_list[i] = 0;
>     else if ( guest_width < sizeof(unsigned long) )
>-        for ( i = PAGE_SIZE/sizeof(unsigned long) - 1; i >= 0; i++ )
>+        for ( i = PAGE_SIZE/sizeof(unsigned long) - 1; i >= 0; i-- )
>             p2m_frame_list_list[i] = ((uint32_t *)p2m_frame_list_list)[i];
> 
>     live_p2m_frame_list =
>@@ -704,19 +710,20 @@ static xen_pfn_t *map_and_save_p2m_table
>     }
> 
>     /* Get a local copy of the live_P2M_frame_list */
>-    if ( !(p2m_frame_list = malloc(P2M_FL_SIZE)) )
>+    if ( !(p2m_frame_list = malloc(P2M_TOOLS_FL_SIZE)) )
>     {
>         ERROR("Couldn't allocate p2m_frame_list array");
>         goto out;
>     }
>-    memcpy(p2m_frame_list, live_p2m_frame_list, P2M_FL_SIZE);
>+    memset(p2m_frame_list, 0, P2M_TOOLS_FL_SIZE);
>+    memcpy(p2m_frame_list, live_p2m_frame_list, P2M_GUEST_FL_SIZE);
> 
>     /* Canonicalize guest's unsigned long vs ours */
>     if ( guest_width > sizeof(unsigned long) )
>         for ( i = 0; i < P2M_FL_ENTRIES; i++ )
>             p2m_frame_list[i] = ((uint64_t *)p2m_frame_list)[i];
>     else if ( guest_width < sizeof(unsigned long) )
>-        for ( i = P2M_FL_ENTRIES - 1; i >= 0; i++ )
>+        for ( i = P2M_FL_ENTRIES - 1; i >= 0; i-- )
>             p2m_frame_list[i] = ((uint32_t *)p2m_frame_list)[i];
> 
> 
>@@ -1559,31 +1566,26 @@ int xc_domain_save(int xc_handle, int io
>         }
> 
>         /* Canonicalise the page table base pointer. */
>-        if ( !MFN_IS_IN_PSEUDOPHYS_MAP(xen_cr3_to_pfn(
>-                                          GET_FIELD(&ctxt, ctrlreg[3]))) )
>+        if ( !MFN_IS_IN_PSEUDOPHYS_MAP(UNFOLD_CR3(
>+                                           GET_FIELD(&ctxt, ctrlreg[3]))) )
>         {
>             ERROR("PT base is not in range of pseudophys map");
>             goto out;
>         }
>         SET_FIELD(&ctxt, ctrlreg[3], 
>-            xen_pfn_to_cr3(
>-                mfn_to_pfn(
>-                    xen_cr3_to_pfn(
>-                        GET_FIELD(&ctxt, ctrlreg[3])))));
>+            FOLD_CR3(mfn_to_pfn(UNFOLD_CR3(GET_FIELD(&ctxt, ctrlreg[3])))));
> 
>         /* Guest pagetable (x86/64) stored in otherwise-unused CR1. */
>         if ( (pt_levels == 4) && ctxt.x64.ctrlreg[1] )
>         {
>-            if ( !MFN_IS_IN_PSEUDOPHYS_MAP(
>-                     xen_cr3_to_pfn(ctxt.x64.ctrlreg[1])) )
>+            if ( !MFN_IS_IN_PSEUDOPHYS_MAP(UNFOLD_CR3(ctxt.x64.ctrlreg[1])) )
>             {
>                 ERROR("PT base is not in range of pseudophys map");
>                 goto out;
>             }
>             /* Least-significant bit means 'valid PFN'. */
>             ctxt.x64.ctrlreg[1] = 1 |
>-                xen_pfn_to_cr3(
>-                    mfn_to_pfn(xen_cr3_to_pfn(ctxt.x64.ctrlreg[1])));
>+                FOLD_CR3(mfn_to_pfn(UNFOLD_CR3(ctxt.x64.ctrlreg[1])));
>         }
> 
>         if ( write_exact(io_fd, &ctxt, ((guest_width==8) 
>diff -r 2a3111016f88 tools/libxc/xg_private.h
>--- a/tools/libxc/xg_private.h	Mon Feb 11 15:59:49 2008 +0000
>+++ b/tools/libxc/xg_private.h	Wed Feb 13 09:36:13 2008 +0000
>@@ -155,7 +155,9 @@ typedef l4_pgentry_64_t l4_pgentry_t;
> #define P2M_FL_ENTRIES  (((p2m_size)+FPP-1)/FPP)
> 
> /* Size in bytes of the pfn_to_mfn_frame_list     */
>-#define P2M_FL_SIZE     ((P2M_FL_ENTRIES)*(guest_width))
>+#define P2M_GUEST_FL_SIZE ((P2M_FL_ENTRIES) * (guest_width))
>+#define P2M_TOOLS_FL_SIZE ((P2M_FL_ENTRIES) *                           \
>+                           MAX((sizeof (xen_pfn_t)), guest_width))
> 
> /* Masks for PTE<->PFN conversions */
> #define MADDR_BITS_X86  ((guest_width == 8) ? 52 : 44)
>diff -r 2a3111016f88 tools/libxc/xg_save_restore.h
>--- a/tools/libxc/xg_save_restore.h	Mon Feb 11 15:59:49 2008 +0000
>+++ b/tools/libxc/xg_save_restore.h	Tue Feb 12 14:30:59 2008 +0000
>@@ -68,6 +68,13 @@ static inline int get_platform_info(int 
> 
>     *guest_width = domctl.u.address_size.size / 8;
> 
>+    /* 64-bit tools will see the 64-bit hvirt_start, but 32-bit guests 
>+     * will be using the compat one. */
>+    if ( *guest_width < sizeof (unsigned long) )
>+        /* XXX need to fix up a way of extracting this value from Xen if
>+         * XXX it becomes variable for domU */
>+        *hvirt_start = 0xf5800000;
>+
>     if (strstr(xen_caps, "xen-3.0-x86_64"))
>         /* Depends on whether it's a compat 32-on-64 guest */
>         *pt_levels = ( (*guest_width == 8) ? 4 : 3 );
>@@ -136,6 +143,16 @@ typedef union
>         (_p)->x32._f = (_v);                    \
> } while (0)
> 
>+#define UNFOLD_CR3(_c)                                                  \
>+  ((uint64_t)((guest_width == 8)                                        \
>+              ? ((_c) >> 12)                                            \
>+              : (((uint32_t)(_c) >> 12) | ((uint32_t)(_c) << 20))))
>+
>+#define FOLD_CR3(_c)                                                    \
>+  ((uint64_t)((guest_width == 8)                                        \
>+              ? ((uint64_t)(_c)) << 12                                  \
>+              : (((uint32_t)(_c) << 12) | ((uint32_t)(_c) >> 20))))
>+
> #define MEMCPY_FIELD(_d, _s, _f) do {                              \
>     if (guest_width == 8)                                          \
>         memcpy(&(_d)->x64._f, &(_s)->x64._f,sizeof((_d)->x64._f)); \

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Attachments on bug 425411: 289421 | 295727 | 295728 | 295729 | 329322