[PATCH v5 10/23] x86/mm: split out descriptor table manipulation code

[Wei Liu <wei.liu2@citrix.com>]

Move the code to pv/descriptor-tables.c. Change u64 to uint64_t while
moving. Use currd in do_update_descriptor.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
---
 xen/arch/x86/mm.c                   | 155 -----------------------------
 xen/arch/x86/pv/Makefile            |   1 +
 xen/arch/x86/pv/descriptor-tables.c | 192 ++++++++++++++++++++++++++++++++++++
 3 files changed, 193 insertions(+), 155 deletions(-)
 create mode 100644 xen/arch/x86/pv/descriptor-tables.c

diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index e505be7cf5..bfdba34468 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -3852,161 +3852,6 @@ long do_update_va_mapping_otherdomain(unsigned long va, u64 val64,
     return rc;
 }
 
-
-
-/*************************
- * Descriptor Tables
- */
-
-void pv_destroy_gdt(struct vcpu *v)
-{
-    l1_pgentry_t *pl1e;
-    unsigned int i;
-    unsigned long pfn, zero_pfn = PFN_DOWN(__pa(zero_page));
-
-    v->arch.pv_vcpu.gdt_ents = 0;
-    pl1e = pv_gdt_ptes(v);
-    for ( i = 0; i < FIRST_RESERVED_GDT_PAGE; i++ )
-    {
-        pfn = l1e_get_pfn(pl1e[i]);
-        if ( (l1e_get_flags(pl1e[i]) & _PAGE_PRESENT) && pfn != zero_pfn )
-            put_page_and_type(mfn_to_page(_mfn(pfn)));
-        l1e_write(&pl1e[i], l1e_from_pfn(zero_pfn, __PAGE_HYPERVISOR_RO));
-        v->arch.pv_vcpu.gdt_frames[i] = 0;
-    }
-}
-
-
-long pv_set_gdt(struct vcpu *v, unsigned long *frames, unsigned int entries)
-{
-    struct domain *d = v->domain;
-    l1_pgentry_t *pl1e;
-    /* NB. There are 512 8-byte entries per GDT page. */
-    unsigned int i, nr_pages = (entries + 511) / 512;
-
-    if ( entries > FIRST_RESERVED_GDT_ENTRY )
-        return -EINVAL;
-
-    /* Check the pages in the new GDT. */
-    for ( i = 0; i < nr_pages; i++ )
-    {
-        struct page_info *page;
-
-        page = get_page_from_gfn(d, frames[i], NULL, P2M_ALLOC);
-        if ( !page )
-            goto fail;
-        if ( !get_page_type(page, PGT_seg_desc_page) )
-        {
-            put_page(page);
-            goto fail;
-        }
-        frames[i] = mfn_x(page_to_mfn(page));
-    }
-
-    /* Tear down the old GDT. */
-    pv_destroy_gdt(v);
-
-    /* Install the new GDT. */
-    v->arch.pv_vcpu.gdt_ents = entries;
-    pl1e = pv_gdt_ptes(v);
-    for ( i = 0; i < nr_pages; i++ )
-    {
-        v->arch.pv_vcpu.gdt_frames[i] = frames[i];
-        l1e_write(&pl1e[i], l1e_from_pfn(frames[i], __PAGE_HYPERVISOR_RW));
-    }
-
-    return 0;
-
- fail:
-    while ( i-- > 0 )
-    {
-        put_page_and_type(mfn_to_page(_mfn(frames[i])));
-    }
-    return -EINVAL;
-}
-
-
-long do_set_gdt(XEN_GUEST_HANDLE_PARAM(xen_ulong_t) frame_list,
-                unsigned int entries)
-{
-    int nr_pages = (entries + 511) / 512;
-    unsigned long frames[16];
-    struct vcpu *curr = current;
-    long ret;
-
-    /* Rechecked in set_gdt, but ensures a sane limit for copy_from_user(). */
-    if ( entries > FIRST_RESERVED_GDT_ENTRY )
-        return -EINVAL;
-
-    if ( copy_from_guest(frames, frame_list, nr_pages) )
-        return -EFAULT;
-
-    domain_lock(curr->domain);
-
-    if ( (ret = pv_set_gdt(curr, frames, entries)) == 0 )
-        flush_tlb_local();
-
-    domain_unlock(curr->domain);
-
-    return ret;
-}
-
-
-long do_update_descriptor(u64 pa, u64 desc)
-{
-    struct domain *dom = current->domain;
-    unsigned long gmfn = pa >> PAGE_SHIFT;
-    unsigned long mfn;
-    unsigned int  offset;
-    struct desc_struct *gdt_pent, d;
-    struct page_info *page;
-    long ret = -EINVAL;
-
-    offset = ((unsigned int)pa & ~PAGE_MASK) / sizeof(struct desc_struct);
-
-    *(u64 *)&d = desc;
-
-    page = get_page_from_gfn(dom, gmfn, NULL, P2M_ALLOC);
-    if ( (((unsigned int)pa % sizeof(struct desc_struct)) != 0) ||
-         !page ||
-         !check_descriptor(dom, &d) )
-    {
-        if ( page )
-            put_page(page);
-        return -EINVAL;
-    }
-    mfn = mfn_x(page_to_mfn(page));
-
-    /* Check if the given frame is in use in an unsafe context. */
-    switch ( page->u.inuse.type_info & PGT_type_mask )
-    {
-    case PGT_seg_desc_page:
-        if ( unlikely(!get_page_type(page, PGT_seg_desc_page)) )
-            goto out;
-        break;
-    default:
-        if ( unlikely(!get_page_type(page, PGT_writable_page)) )
-            goto out;
-        break;
-    }
-
-    paging_mark_dirty(dom, _mfn(mfn));
-
-    /* All is good so make the update. */
-    gdt_pent = map_domain_page(_mfn(mfn));
-    write_atomic((uint64_t *)&gdt_pent[offset], *(uint64_t *)&d);
-    unmap_domain_page(gdt_pent);
-
-    put_page_type(page);
-
-    ret = 0; /* success */
-
- out:
-    put_page(page);
-
-    return ret;
-}
-
 typedef struct e820entry e820entry_t;
 DEFINE_XEN_GUEST_HANDLE(e820entry_t);
 
diff --git a/xen/arch/x86/pv/Makefile b/xen/arch/x86/pv/Makefile
index a692ee6432..bac2792aa2 100644
--- a/xen/arch/x86/pv/Makefile
+++ b/xen/arch/x86/pv/Makefile
@@ -1,4 +1,5 @@
 obj-y += callback.o
+obj-y += descriptor-tables.o
 obj-y += domain.o
 obj-y += emulate.o
 obj-y += emul-gate-op.o
diff --git a/xen/arch/x86/pv/descriptor-tables.c b/xen/arch/x86/pv/descriptor-tables.c
new file mode 100644
index 0000000000..04fb37f2ce
--- /dev/null
+++ b/xen/arch/x86/pv/descriptor-tables.c
@@ -0,0 +1,192 @@
+/*
+ * arch/x86/pv/descriptor-tables.c
+ *
+ * Descriptor table manipulation code for PV guests
+ *
+ * Copyright (c) 2002-2005 K A Fraser
+ * Copyright (c) 2004 Christian Limpach
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms and conditions of the GNU General Public
+ * License, version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <xen/guest_access.h>
+#include <xen/hypercall.h>
+
+#include <asm/p2m.h>
+#include <asm/pv/mm.h>
+
+/* Override macros from asm/page.h to make them work with mfn_t */
+#undef mfn_to_page
+#define mfn_to_page(mfn) __mfn_to_page(mfn_x(mfn))
+#undef page_to_mfn
+#define page_to_mfn(pg) _mfn(__page_to_mfn(pg))
+
+/*******************
+ * Descriptor Tables
+ */
+
+void pv_destroy_gdt(struct vcpu *v)
+{
+    l1_pgentry_t *pl1e;
+    unsigned int i;
+    unsigned long pfn, zero_pfn = PFN_DOWN(__pa(zero_page));
+
+    v->arch.pv_vcpu.gdt_ents = 0;
+    pl1e = pv_gdt_ptes(v);
+    for ( i = 0; i < FIRST_RESERVED_GDT_PAGE; i++ )
+    {
+        pfn = l1e_get_pfn(pl1e[i]);
+        if ( (l1e_get_flags(pl1e[i]) & _PAGE_PRESENT) && pfn != zero_pfn )
+            put_page_and_type(mfn_to_page(_mfn(pfn)));
+        l1e_write(&pl1e[i], l1e_from_pfn(zero_pfn, __PAGE_HYPERVISOR_RO));
+        v->arch.pv_vcpu.gdt_frames[i] = 0;
+    }
+}
+
+long pv_set_gdt(struct vcpu *v, unsigned long *frames, unsigned int entries)
+{
+    struct domain *d = v->domain;
+    l1_pgentry_t *pl1e;
+    /* NB. There are 512 8-byte entries per GDT page. */
+    unsigned int i, nr_pages = (entries + 511) / 512;
+
+    if ( entries > FIRST_RESERVED_GDT_ENTRY )
+        return -EINVAL;
+
+    /* Check the pages in the new GDT. */
+    for ( i = 0; i < nr_pages; i++ )
+    {
+        struct page_info *page;
+
+        page = get_page_from_gfn(d, frames[i], NULL, P2M_ALLOC);
+        if ( !page )
+            goto fail;
+        if ( !get_page_type(page, PGT_seg_desc_page) )
+        {
+            put_page(page);
+            goto fail;
+        }
+        frames[i] = mfn_x(page_to_mfn(page));
+    }
+
+    /* Tear down the old GDT. */
+    pv_destroy_gdt(v);
+
+    /* Install the new GDT. */
+    v->arch.pv_vcpu.gdt_ents = entries;
+    pl1e = pv_gdt_ptes(v);
+    for ( i = 0; i < nr_pages; i++ )
+    {
+        v->arch.pv_vcpu.gdt_frames[i] = frames[i];
+        l1e_write(&pl1e[i], l1e_from_pfn(frames[i], __PAGE_HYPERVISOR_RW));
+    }
+
+    return 0;
+
+ fail:
+    while ( i-- > 0 )
+    {
+        put_page_and_type(mfn_to_page(_mfn(frames[i])));
+    }
+    return -EINVAL;
+}
+
+long do_set_gdt(XEN_GUEST_HANDLE_PARAM(xen_ulong_t) frame_list,
+                unsigned int entries)
+{
+    int nr_pages = (entries + 511) / 512;
+    unsigned long frames[16];
+    struct vcpu *curr = current;
+    long ret;
+
+    /* Rechecked in set_gdt, but ensures a sane limit for copy_from_user(). */
+    if ( entries > FIRST_RESERVED_GDT_ENTRY )
+        return -EINVAL;
+
+    if ( copy_from_guest(frames, frame_list, nr_pages) )
+        return -EFAULT;
+
+    domain_lock(curr->domain);
+
+    if ( (ret = pv_set_gdt(curr, frames, entries)) == 0 )
+        flush_tlb_local();
+
+    domain_unlock(curr->domain);
+
+    return ret;
+}
+
+long do_update_descriptor(uint64_t pa, uint64_t desc)
+{
+    struct domain *currd = current->domain;
+    unsigned long gmfn = pa >> PAGE_SHIFT;
+    unsigned long mfn;
+    unsigned int  offset;
+    struct desc_struct *gdt_pent, d;
+    struct page_info *page;
+    long ret = -EINVAL;
+
+    offset = ((unsigned int)pa & ~PAGE_MASK) / sizeof(struct desc_struct);
+
+    *(uint64_t *)&d = desc;
+
+    page = get_page_from_gfn(currd, gmfn, NULL, P2M_ALLOC);
+    if ( (((unsigned int)pa % sizeof(struct desc_struct)) != 0) ||
+         !page ||
+         !check_descriptor(currd, &d) )
+    {
+        if ( page )
+            put_page(page);
+        return -EINVAL;
+    }
+    mfn = mfn_x(page_to_mfn(page));
+
+    /* Check if the given frame is in use in an unsafe context. */
+    switch ( page->u.inuse.type_info & PGT_type_mask )
+    {
+    case PGT_seg_desc_page:
+        if ( unlikely(!get_page_type(page, PGT_seg_desc_page)) )
+            goto out;
+        break;
+    default:
+        if ( unlikely(!get_page_type(page, PGT_writable_page)) )
+            goto out;
+        break;
+    }
+
+    paging_mark_dirty(currd, _mfn(mfn));
+
+    /* All is good so make the update. */
+    gdt_pent = map_domain_page(_mfn(mfn));
+    write_atomic((uint64_t *)&gdt_pent[offset], *(uint64_t *)&d);
+    unmap_domain_page(gdt_pent);
+
+    put_page_type(page);
+
+    ret = 0; /* success */
+
+ out:
+    put_page(page);
+
+    return ret;
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
-- 
2.11.0


_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
https://lists.xen.org/xen-devel