[xen master] tools/dombuilder: Remove clear_page() from xc_dom_boot.c

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[xen master] tools/dombuilder: Remove clear_page() from xc_dom_boot.c

patchbot
commit 86cf189a957129ea1ad6468fe9a0887b9e2819f3
Author:     Andrew Cooper <[hidden email]>
AuthorDate: Thu Oct 12 20:19:06 2017 +0100
Commit:     Wei Liu <[hidden email]>
CommitDate: Thu Nov 2 16:47:10 2017 +0000

    tools/dombuilder: Remove clear_page() from xc_dom_boot.c
   
    pfn 0 is a legitimate (albeit unlikely) frame to use, so skipping it is wrong.
    This behaviour appears to exists simply to cover the fact that zero is the
    default value of an uninitialised field in dom.
   
    ARM already clears the frames at the point that the pfns are allocated,
    meaning that the added clear_page() is wasteful.  Alter x86 to match ARM and
    clear the page when it is allocated.
   
    Signed-off-by: Andrew Cooper <[hidden email]>
    Acked-by: Wei Liu <[hidden email]>
    Tested-by: Julien Grall <[hidden email]>
    Release-acked-by: Julien Grall <[hidden email]>
---
 tools/libxc/xc_dom_arm.c  |  3 ++-
 tools/libxc/xc_dom_boot.c | 26 --------------------------
 tools/libxc/xc_dom_x86.c  |  8 ++++++++
 3 files changed, 10 insertions(+), 27 deletions(-)

diff --git a/tools/libxc/xc_dom_arm.c b/tools/libxc/xc_dom_arm.c
index 7c4997a..fce151d 100644
--- a/tools/libxc/xc_dom_arm.c
+++ b/tools/libxc/xc_dom_arm.c
@@ -91,7 +91,8 @@ static int alloc_magic_pages(struct xc_dom_image *dom)
     xc_clear_domain_page(dom->xch, dom->guest_domid, dom->console_pfn);
     xc_clear_domain_page(dom->xch, dom->guest_domid, dom->xenstore_pfn);
     xc_clear_domain_page(dom->xch, dom->guest_domid, base + MEMACCESS_PFN_OFFSET);
-    xc_clear_domain_page(dom->xch, dom->guest_domid, base + VUART_PFN_OFFSET);
+    xc_clear_domain_page(dom->xch, dom->guest_domid, dom->vuart_gfn);
+
     xc_hvm_param_set(dom->xch, dom->guest_domid, HVM_PARAM_CONSOLE_PFN,
             dom->console_pfn);
     xc_hvm_param_set(dom->xch, dom->guest_domid, HVM_PARAM_STORE_PFN,
diff --git a/tools/libxc/xc_dom_boot.c b/tools/libxc/xc_dom_boot.c
index 40eb518..2e5681d 100644
--- a/tools/libxc/xc_dom_boot.c
+++ b/tools/libxc/xc_dom_boot.c
@@ -62,25 +62,6 @@ static int setup_hypercall_page(struct xc_dom_image *dom)
     return rc;
 }
 
-static int clear_page(struct xc_dom_image *dom, xen_pfn_t pfn)
-{
-    xen_pfn_t dst;
-    int rc;
-
-    if ( pfn == 0 )
-        return 0;
-
-    dst = xc_dom_p2m(dom, pfn);
-    DOMPRINTF("%s: pfn 0x%" PRIpfn ", mfn 0x%" PRIpfn "",
-              __FUNCTION__, pfn, dst);
-    rc = xc_clear_domain_page(dom->xch, dom->guest_domid, dst);
-    if ( rc != 0 )
-        xc_dom_panic(dom->xch, XC_INTERNAL_ERROR,
-                     "%s: xc_clear_domain_page failed (pfn 0x%" PRIpfn
-                     ", rc=%d)", __FUNCTION__, pfn, rc);
-    return rc;
-}
-
 
 /* ------------------------------------------------------------------------ */
 
@@ -222,13 +203,6 @@ int xc_dom_boot_image(struct xc_dom_image *dom)
         if ( (rc = dom->arch_hooks->setup_pgtables(dom)) != 0 )
             return rc;
 
-    if ( (rc = clear_page(dom, dom->console_pfn)) != 0 )
-        return rc;
-    if ( (rc = clear_page(dom, dom->xenstore_pfn)) != 0 )
-        return rc;
-    if ( (rc = clear_page(dom, dom->vuart_gfn)) != 0 )
-        return rc;
-
     /* start info page */
     if ( dom->arch_hooks->start_info )
         dom->arch_hooks->start_info(dom);
diff --git a/tools/libxc/xc_dom_x86.c b/tools/libxc/xc_dom_x86.c
index 47db218..bff68a0 100644
--- a/tools/libxc/xc_dom_x86.c
+++ b/tools/libxc/xc_dom_x86.c
@@ -543,10 +543,14 @@ static int alloc_magic_pages_pv(struct xc_dom_image *dom)
     dom->xenstore_pfn = xc_dom_alloc_page(dom, "xenstore");
     if ( dom->xenstore_pfn == INVALID_PFN )
         return -1;
+    xc_clear_domain_page(dom->xch, dom->guest_domid,
+                         xc_dom_p2m(dom, dom->xenstore_pfn));
 
     dom->console_pfn = xc_dom_alloc_page(dom, "console");
     if ( dom->console_pfn == INVALID_PFN )
         return -1;
+    xc_clear_domain_page(dom->xch, dom->guest_domid,
+                         xc_dom_p2m(dom, dom->console_pfn));
 
     dom->alloc_bootstack = 1;
 
@@ -696,7 +700,11 @@ static int alloc_magic_pages_hvm(struct xc_dom_image *dom)
                      special_pfn(SPECIALPAGE_IDENT_PT) << PAGE_SHIFT);
 
     dom->console_pfn = special_pfn(SPECIALPAGE_CONSOLE);
+    xc_clear_domain_page(dom->xch, dom->guest_domid, dom->console_pfn);
+
     dom->xenstore_pfn = special_pfn(SPECIALPAGE_XENSTORE);
+    xc_clear_domain_page(dom->xch, dom->guest_domid, dom->xenstore_pfn);
+
     dom->parms.virt_hypercall = -1;
 
     rc = 0;
--
generated by git-patchbot for /home/xen/git/xen.git#master

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