[PATCH v3 15/21] x86/mm: split out PV grant table code

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

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
---
 xen/arch/x86/mm.c             | 349 --------------------------------------
 xen/arch/x86/pv/Makefile      |   1 +
 xen/arch/x86/pv/grant_table.c | 386 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 387 insertions(+), 349 deletions(-)
 create mode 100644 xen/arch/x86/pv/grant_table.c

diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 5a9cc7173a..897db4cfb9 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -3844,355 +3844,6 @@ long do_mmu_update(
 }
 
 
-static int create_grant_pte_mapping(
-    uint64_t pte_addr, l1_pgentry_t nl1e, struct vcpu *v)
-{
-    int rc = GNTST_okay;
-    void *va;
-    unsigned long gmfn, mfn;
-    struct page_info *page;
-    l1_pgentry_t ol1e;
-    struct domain *d = v->domain;
-
-    adjust_guest_l1e(nl1e, d);
-
-    gmfn = pte_addr >> PAGE_SHIFT;
-    page = get_page_from_gfn(d, gmfn, NULL, P2M_ALLOC);
-
-    if ( unlikely(!page) )
-    {
-        gdprintk(XENLOG_WARNING, "Could not get page for normal update\n");
-        return GNTST_general_error;
-    }
-
-    mfn = page_to_mfn(page);
-    va = map_domain_page(_mfn(mfn));
-    va = (void *)((unsigned long)va + ((unsigned long)pte_addr & ~PAGE_MASK));
-
-    if ( !page_lock(page) )
-    {
-        rc = GNTST_general_error;
-        goto failed;
-    }
-
-    if ( (page->u.inuse.type_info & PGT_type_mask) != PGT_l1_page_table )
-    {
-        page_unlock(page);
-        rc = GNTST_general_error;
-        goto failed;
-    }
-
-    ol1e = *(l1_pgentry_t *)va;
-    if ( !UPDATE_ENTRY(l1, (l1_pgentry_t *)va, ol1e, nl1e, mfn, v, 0) )
-    {
-        page_unlock(page);
-        rc = GNTST_general_error;
-        goto failed;
-    }
-
-    page_unlock(page);
-
-    put_page_from_l1e(ol1e, d);
-
- failed:
-    unmap_domain_page(va);
-    put_page(page);
-
-    return rc;
-}
-
-static int destroy_grant_pte_mapping(
-    uint64_t addr, unsigned long frame, struct domain *d)
-{
-    int rc = GNTST_okay;
-    void *va;
-    unsigned long gmfn, mfn;
-    struct page_info *page;
-    l1_pgentry_t ol1e;
-
-    gmfn = addr >> PAGE_SHIFT;
-    page = get_page_from_gfn(d, gmfn, NULL, P2M_ALLOC);
-
-    if ( unlikely(!page) )
-    {
-        gdprintk(XENLOG_WARNING, "Could not get page for normal update\n");
-        return GNTST_general_error;
-    }
-
-    mfn = page_to_mfn(page);
-    va = map_domain_page(_mfn(mfn));
-    va = (void *)((unsigned long)va + ((unsigned long)addr & ~PAGE_MASK));
-
-    if ( !page_lock(page) )
-    {
-        rc = GNTST_general_error;
-        goto failed;
-    }
-
-    if ( (page->u.inuse.type_info & PGT_type_mask) != PGT_l1_page_table )
-    {
-        page_unlock(page);
-        rc = GNTST_general_error;
-        goto failed;
-    }
-
-    ol1e = *(l1_pgentry_t *)va;
-
-    /* Check that the virtual address supplied is actually mapped to frame. */
-    if ( unlikely(l1e_get_pfn(ol1e) != frame) )
-    {
-        page_unlock(page);
-        gdprintk(XENLOG_WARNING,
-                 "PTE entry %"PRIpte" for address %"PRIx64" doesn't match frame %lx\n",
-                 l1e_get_intpte(ol1e), addr, frame);
-        rc = GNTST_general_error;
-        goto failed;
-    }
-
-    /* Delete pagetable entry. */
-    if ( unlikely(!UPDATE_ENTRY(l1,
-                                (l1_pgentry_t *)va, ol1e, l1e_empty(), mfn,
-                                d->vcpu[0] /* Change if we go to per-vcpu shadows. */,
-                                0)) )
-    {
-        page_unlock(page);
-        gdprintk(XENLOG_WARNING, "Cannot delete PTE entry at %p\n", va);
-        rc = GNTST_general_error;
-        goto failed;
-    }
-
-    page_unlock(page);
-
- failed:
-    unmap_domain_page(va);
-    put_page(page);
-    return rc;
-}
-
-
-static int create_grant_va_mapping(
-    unsigned long va, l1_pgentry_t nl1e, struct vcpu *v)
-{
-    l1_pgentry_t *pl1e, ol1e;
-    struct domain *d = v->domain;
-    unsigned long gl1mfn;
-    struct page_info *l1pg;
-    int okay;
-
-    adjust_guest_l1e(nl1e, d);
-
-    pl1e = pv_map_guest_l1e(va, &gl1mfn);
-    if ( !pl1e )
-    {
-        gdprintk(XENLOG_WARNING, "Could not find L1 PTE for address %lx\n", va);
-        return GNTST_general_error;
-    }
-
-    if ( get_page_from_pagenr(gl1mfn, current->domain) )
-    {
-        pv_unmap_guest_l1e(pl1e);
-        return GNTST_general_error;
-    }
-
-    l1pg = mfn_to_page(gl1mfn);
-    if ( !page_lock(l1pg) )
-    {
-        put_page(l1pg);
-        pv_unmap_guest_l1e(pl1e);
-        return GNTST_general_error;
-    }
-
-    if ( (l1pg->u.inuse.type_info & PGT_type_mask) != PGT_l1_page_table )
-    {
-        page_unlock(l1pg);
-        put_page(l1pg);
-        pv_unmap_guest_l1e(pl1e);
-        return GNTST_general_error;
-    }
-
-    ol1e = *pl1e;
-    okay = UPDATE_ENTRY(l1, pl1e, ol1e, nl1e, gl1mfn, v, 0);
-
-    page_unlock(l1pg);
-    put_page(l1pg);
-    pv_unmap_guest_l1e(pl1e);
-
-    if ( okay )
-        put_page_from_l1e(ol1e, d);
-
-    return okay ? GNTST_okay : GNTST_general_error;
-}
-
-static int replace_grant_va_mapping(
-    unsigned long addr, unsigned long frame, l1_pgentry_t nl1e, struct vcpu *v)
-{
-    l1_pgentry_t *pl1e, ol1e;
-    unsigned long gl1mfn;
-    struct page_info *l1pg;
-    int rc = 0;
-
-    pl1e = pv_map_guest_l1e(addr, &gl1mfn);
-    if ( !pl1e )
-    {
-        gdprintk(XENLOG_WARNING, "Could not find L1 PTE for address %lx\n", addr);
-        return GNTST_general_error;
-    }
-
-    if ( get_page_from_pagenr(gl1mfn, current->domain) )
-    {
-        rc = GNTST_general_error;
-        goto out;
-    }
-
-    l1pg = mfn_to_page(gl1mfn);
-    if ( !page_lock(l1pg) )
-    {
-        rc = GNTST_general_error;
-        put_page(l1pg);
-        goto out;
-    }
-
-    if ( (l1pg->u.inuse.type_info & PGT_type_mask) != PGT_l1_page_table )
-    {
-        rc = GNTST_general_error;
-        goto unlock_and_out;
-    }
-
-    ol1e = *pl1e;
-
-    /* Check that the virtual address supplied is actually mapped to frame. */
-    if ( unlikely(l1e_get_pfn(ol1e) != frame) )
-    {
-        gdprintk(XENLOG_WARNING,
-                 "PTE entry %lx for address %lx doesn't match frame %lx\n",
-                 l1e_get_pfn(ol1e), addr, frame);
-        rc = GNTST_general_error;
-        goto unlock_and_out;
-    }
-
-    /* Delete pagetable entry. */
-    if ( unlikely(!UPDATE_ENTRY(l1, pl1e, ol1e, nl1e, gl1mfn, v, 0)) )
-    {
-        gdprintk(XENLOG_WARNING, "Cannot delete PTE entry at %p\n", pl1e);
-        rc = GNTST_general_error;
-        goto unlock_and_out;
-    }
-
- unlock_and_out:
-    page_unlock(l1pg);
-    put_page(l1pg);
- out:
-    pv_unmap_guest_l1e(pl1e);
-    return rc;
-}
-
-static int destroy_grant_va_mapping(
-    unsigned long addr, unsigned long frame, struct vcpu *v)
-{
-    return replace_grant_va_mapping(addr, frame, l1e_empty(), v);
-}
-
-int create_grant_pv_mapping(uint64_t addr, unsigned long frame,
-                            unsigned int flags, unsigned int cache_flags)
-{
-    l1_pgentry_t pte;
-    uint32_t grant_pte_flags;
-
-    grant_pte_flags =
-        _PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_GNTTAB;
-    if ( cpu_has_nx )
-        grant_pte_flags |= _PAGE_NX_BIT;
-
-    pte = l1e_from_pfn(frame, grant_pte_flags);
-    if ( (flags & GNTMAP_application_map) )
-        l1e_add_flags(pte,_PAGE_USER);
-    if ( !(flags & GNTMAP_readonly) )
-        l1e_add_flags(pte,_PAGE_RW);
-
-    l1e_add_flags(pte,
-                  ((flags >> _GNTMAP_guest_avail0) * _PAGE_AVAIL0)
-                   & _PAGE_AVAIL);
-
-    l1e_add_flags(pte, cacheattr_to_pte_flags(cache_flags >> 5));
-
-    if ( flags & GNTMAP_contains_pte )
-        return create_grant_pte_mapping(addr, pte, current);
-    return create_grant_va_mapping(addr, pte, current);
-}
-
-int replace_grant_pv_mapping(uint64_t addr, unsigned long frame,
-                             uint64_t new_addr, unsigned int flags)
-{
-    struct vcpu *curr = current;
-    l1_pgentry_t *pl1e, ol1e;
-    unsigned long gl1mfn;
-    struct page_info *l1pg;
-    int rc;
-
-    if ( flags & GNTMAP_contains_pte )
-    {
-        if ( !new_addr )
-            return destroy_grant_pte_mapping(addr, frame, curr->domain);
-
-        return GNTST_general_error;
-    }
-
-    if ( !new_addr )
-        return destroy_grant_va_mapping(addr, frame, curr);
-
-    pl1e = pv_map_guest_l1e(new_addr, &gl1mfn);
-    if ( !pl1e )
-    {
-        gdprintk(XENLOG_WARNING,
-                 "Could not find L1 PTE for address %"PRIx64"\n", new_addr);
-        return GNTST_general_error;
-    }
-
-    if ( get_page_from_pagenr(gl1mfn, current->domain) )
-    {
-        pv_unmap_guest_l1e(pl1e);
-        return GNTST_general_error;
-    }
-
-    l1pg = mfn_to_page(gl1mfn);
-    if ( !page_lock(l1pg) )
-    {
-        put_page(l1pg);
-        pv_unmap_guest_l1e(pl1e);
-        return GNTST_general_error;
-    }
-
-    if ( (l1pg->u.inuse.type_info & PGT_type_mask) != PGT_l1_page_table )
-    {
-        page_unlock(l1pg);
-        put_page(l1pg);
-        pv_unmap_guest_l1e(pl1e);
-        return GNTST_general_error;
-    }
-
-    ol1e = *pl1e;
-
-    if ( unlikely(!UPDATE_ENTRY(l1, pl1e, ol1e, l1e_empty(),
-                                gl1mfn, curr, 0)) )
-    {
-        page_unlock(l1pg);
-        put_page(l1pg);
-        gdprintk(XENLOG_WARNING, "Cannot delete PTE entry at %p\n", pl1e);
-        pv_unmap_guest_l1e(pl1e);
-        return GNTST_general_error;
-    }
-
-    page_unlock(l1pg);
-    put_page(l1pg);
-    pv_unmap_guest_l1e(pl1e);
-
-    rc = replace_grant_va_mapping(addr, frame, ol1e, curr);
-    if ( rc )
-        put_page_from_l1e(ol1e, curr->domain);
-
-    return rc;
-}
-
 int donate_page(
     struct domain *d, struct page_info *page, unsigned int memflags)
 {
diff --git a/xen/arch/x86/pv/Makefile b/xen/arch/x86/pv/Makefile
index 016b1b6e8f..501c766cc2 100644
--- a/xen/arch/x86/pv/Makefile
+++ b/xen/arch/x86/pv/Makefile
@@ -6,6 +6,7 @@ obj-y += emul-inv-op.o
 obj-y += emul-mmio-op.o
 obj-y += emul-priv-op.o
 obj-y += emul-ptwr-op.o
+obj-y += grant_table.o
 obj-y += hypercall.o
 obj-y += iret.o
 obj-y += misc-hypercalls.o
diff --git a/xen/arch/x86/pv/grant_table.c b/xen/arch/x86/pv/grant_table.c
new file mode 100644
index 0000000000..6c22cd01a7
--- /dev/null
+++ b/xen/arch/x86/pv/grant_table.c
@@ -0,0 +1,386 @@
+/******************************************************************************
+ * arch/x86/pv/grant_table.c
+ *
+ * Grant table interfaces for PV guests
+ *
+ * Copyright (C) 2017 Wei Liu <wei.liu2@citrix.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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/types.h>
+
+#include <public/grant_table.h>
+
+#include <asm/p2m.h>
+#include <asm/pv/mm.h>
+
+static int create_grant_pte_mapping(uint64_t pte_addr, l1_pgentry_t nl1e,
+                                    struct vcpu *v)
+{
+    int rc = GNTST_okay;
+    void *va;
+    unsigned long gmfn, mfn;
+    struct page_info *page;
+    l1_pgentry_t ol1e;
+    struct domain *d = v->domain;
+
+    adjust_guest_l1e(nl1e, d);
+
+    gmfn = pte_addr >> PAGE_SHIFT;
+    page = get_page_from_gfn(d, gmfn, NULL, P2M_ALLOC);
+
+    if ( unlikely(!page) )
+    {
+        gdprintk(XENLOG_WARNING, "Could not get page for normal update\n");
+        return GNTST_general_error;
+    }
+
+    mfn = page_to_mfn(page);
+    va = map_domain_page(_mfn(mfn));
+    va = (void *)((unsigned long)va + ((unsigned long)pte_addr & ~PAGE_MASK));
+
+    if ( !page_lock(page) )
+    {
+        rc = GNTST_general_error;
+        goto failed;
+    }
+
+    if ( (page->u.inuse.type_info & PGT_type_mask) != PGT_l1_page_table )
+    {
+        page_unlock(page);
+        rc = GNTST_general_error;
+        goto failed;
+    }
+
+    ol1e = *(l1_pgentry_t *)va;
+    if ( !UPDATE_ENTRY(l1, (l1_pgentry_t *)va, ol1e, nl1e, mfn, v, 0) )
+    {
+        page_unlock(page);
+        rc = GNTST_general_error;
+        goto failed;
+    }
+
+    page_unlock(page);
+
+    put_page_from_l1e(ol1e, d);
+
+ failed:
+    unmap_domain_page(va);
+    put_page(page);
+
+    return rc;
+}
+
+static int destroy_grant_pte_mapping(uint64_t addr, unsigned long frame,
+                                     struct domain *d)
+{
+    int rc = GNTST_okay;
+    void *va;
+    unsigned long gmfn, mfn;
+    struct page_info *page;
+    l1_pgentry_t ol1e;
+
+    gmfn = addr >> PAGE_SHIFT;
+    page = get_page_from_gfn(d, gmfn, NULL, P2M_ALLOC);
+
+    if ( unlikely(!page) )
+    {
+        gdprintk(XENLOG_WARNING, "Could not get page for normal update\n");
+        return GNTST_general_error;
+    }
+
+    mfn = page_to_mfn(page);
+    va = map_domain_page(_mfn(mfn));
+    va = (void *)((unsigned long)va + ((unsigned long)addr & ~PAGE_MASK));
+
+    if ( !page_lock(page) )
+    {
+        rc = GNTST_general_error;
+        goto failed;
+    }
+
+    if ( (page->u.inuse.type_info & PGT_type_mask) != PGT_l1_page_table )
+    {
+        page_unlock(page);
+        rc = GNTST_general_error;
+        goto failed;
+    }
+
+    ol1e = *(l1_pgentry_t *)va;
+
+    /* Check that the virtual address supplied is actually mapped to frame. */
+    if ( unlikely(l1e_get_pfn(ol1e) != frame) )
+    {
+        page_unlock(page);
+        gdprintk(XENLOG_WARNING,
+                 "PTE entry %"PRIpte" for address %"PRIx64" doesn't match frame %lx\n",
+                 l1e_get_intpte(ol1e), addr, frame);
+        rc = GNTST_general_error;
+        goto failed;
+    }
+
+    /* Delete pagetable entry. */
+    if ( unlikely(!UPDATE_ENTRY(l1,
+                                (l1_pgentry_t *)va, ol1e, l1e_empty(), mfn,
+                                d->vcpu[0] /* Change if we go to per-vcpu shadows. */,
+                                0)) )
+    {
+        page_unlock(page);
+        gdprintk(XENLOG_WARNING, "Cannot delete PTE entry at %p\n", va);
+        rc = GNTST_general_error;
+        goto failed;
+    }
+
+    page_unlock(page);
+
+ failed:
+    unmap_domain_page(va);
+    put_page(page);
+    return rc;
+}
+
+
+static int create_grant_va_mapping(unsigned long va, l1_pgentry_t nl1e,
+                                   struct vcpu *v)
+{
+    l1_pgentry_t *pl1e, ol1e;
+    struct domain *d = v->domain;
+    unsigned long gl1mfn;
+    struct page_info *l1pg;
+    int okay;
+
+    adjust_guest_l1e(nl1e, d);
+
+    pl1e = pv_map_guest_l1e(va, &gl1mfn);
+    if ( !pl1e )
+    {
+        gdprintk(XENLOG_WARNING, "Could not find L1 PTE for address %lx\n", va);
+        return GNTST_general_error;
+    }
+
+    if ( get_page_from_pagenr(gl1mfn, current->domain) )
+    {
+        pv_unmap_guest_l1e(pl1e);
+        return GNTST_general_error;
+    }
+
+    l1pg = mfn_to_page(gl1mfn);
+    if ( !page_lock(l1pg) )
+    {
+        put_page(l1pg);
+        pv_unmap_guest_l1e(pl1e);
+        return GNTST_general_error;
+    }
+
+    if ( (l1pg->u.inuse.type_info & PGT_type_mask) != PGT_l1_page_table )
+    {
+        page_unlock(l1pg);
+        put_page(l1pg);
+        pv_unmap_guest_l1e(pl1e);
+        return GNTST_general_error;
+    }
+
+    ol1e = *pl1e;
+    okay = UPDATE_ENTRY(l1, pl1e, ol1e, nl1e, gl1mfn, v, 0);
+
+    page_unlock(l1pg);
+    put_page(l1pg);
+    pv_unmap_guest_l1e(pl1e);
+
+    if ( okay )
+        put_page_from_l1e(ol1e, d);
+
+    return okay ? GNTST_okay : GNTST_general_error;
+}
+
+static int replace_grant_va_mapping(unsigned long addr, unsigned long frame,
+                                    l1_pgentry_t nl1e, struct vcpu *v)
+{
+    l1_pgentry_t *pl1e, ol1e;
+    unsigned long gl1mfn;
+    struct page_info *l1pg;
+    int rc = 0;
+
+    pl1e = pv_map_guest_l1e(addr, &gl1mfn);
+    if ( !pl1e )
+    {
+        gdprintk(XENLOG_WARNING, "Could not find L1 PTE for address %lx\n", addr);
+        return GNTST_general_error;
+    }
+
+    if ( get_page_from_pagenr(gl1mfn, current->domain) )
+    {
+        rc = GNTST_general_error;
+        goto out;
+    }
+
+    l1pg = mfn_to_page(gl1mfn);
+    if ( !page_lock(l1pg) )
+    {
+        rc = GNTST_general_error;
+        put_page(l1pg);
+        goto out;
+    }
+
+    if ( (l1pg->u.inuse.type_info & PGT_type_mask) != PGT_l1_page_table )
+    {
+        rc = GNTST_general_error;
+        goto unlock_and_out;
+    }
+
+    ol1e = *pl1e;
+
+    /* Check that the virtual address supplied is actually mapped to frame. */
+    if ( unlikely(l1e_get_pfn(ol1e) != frame) )
+    {
+        gdprintk(XENLOG_WARNING,
+                 "PTE entry %lx for address %lx doesn't match frame %lx\n",
+                 l1e_get_pfn(ol1e), addr, frame);
+        rc = GNTST_general_error;
+        goto unlock_and_out;
+    }
+
+    /* Delete pagetable entry. */
+    if ( unlikely(!UPDATE_ENTRY(l1, pl1e, ol1e, nl1e, gl1mfn, v, 0)) )
+    {
+        gdprintk(XENLOG_WARNING, "Cannot delete PTE entry at %p\n", pl1e);
+        rc = GNTST_general_error;
+        goto unlock_and_out;
+    }
+
+ unlock_and_out:
+    page_unlock(l1pg);
+    put_page(l1pg);
+ out:
+    pv_unmap_guest_l1e(pl1e);
+    return rc;
+}
+
+static int destroy_grant_va_mapping(unsigned long addr, unsigned long frame,
+                                    struct vcpu *v)
+{
+    return replace_grant_va_mapping(addr, frame, l1e_empty(), v);
+}
+
+int create_grant_pv_mapping(uint64_t addr, unsigned long frame,
+                            unsigned int flags, unsigned int cache_flags)
+{
+    l1_pgentry_t pte;
+    uint32_t grant_pte_flags;
+
+    grant_pte_flags =
+        _PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_GNTTAB;
+    if ( cpu_has_nx )
+        grant_pte_flags |= _PAGE_NX_BIT;
+
+    pte = l1e_from_pfn(frame, grant_pte_flags);
+    if ( (flags & GNTMAP_application_map) )
+        l1e_add_flags(pte,_PAGE_USER);
+    if ( !(flags & GNTMAP_readonly) )
+        l1e_add_flags(pte,_PAGE_RW);
+
+    l1e_add_flags(pte,
+                  ((flags >> _GNTMAP_guest_avail0) * _PAGE_AVAIL0)
+                   & _PAGE_AVAIL);
+
+    l1e_add_flags(pte, cacheattr_to_pte_flags(cache_flags >> 5));
+
+    if ( flags & GNTMAP_contains_pte )
+        return create_grant_pte_mapping(addr, pte, current);
+    return create_grant_va_mapping(addr, pte, current);
+}
+
+int replace_grant_pv_mapping(uint64_t addr, unsigned long frame,
+                             uint64_t new_addr, unsigned int flags)
+{
+    struct vcpu *curr = current;
+    l1_pgentry_t *pl1e, ol1e;
+    unsigned long gl1mfn;
+    struct page_info *l1pg;
+    int rc;
+
+    if ( flags & GNTMAP_contains_pte )
+    {
+        if ( !new_addr )
+            return destroy_grant_pte_mapping(addr, frame, curr->domain);
+
+        return GNTST_general_error;
+    }
+
+    if ( !new_addr )
+        return destroy_grant_va_mapping(addr, frame, curr);
+
+    pl1e = pv_map_guest_l1e(new_addr, &gl1mfn);
+    if ( !pl1e )
+    {
+        gdprintk(XENLOG_WARNING,
+                 "Could not find L1 PTE for address %"PRIx64"\n", new_addr);
+        return GNTST_general_error;
+    }
+
+    if ( get_page_from_pagenr(gl1mfn, current->domain) )
+    {
+        pv_unmap_guest_l1e(pl1e);
+        return GNTST_general_error;
+    }
+
+    l1pg = mfn_to_page(gl1mfn);
+    if ( !page_lock(l1pg) )
+    {
+        put_page(l1pg);
+        pv_unmap_guest_l1e(pl1e);
+        return GNTST_general_error;
+    }
+
+    if ( (l1pg->u.inuse.type_info & PGT_type_mask) != PGT_l1_page_table )
+    {
+        page_unlock(l1pg);
+        put_page(l1pg);
+        pv_unmap_guest_l1e(pl1e);
+        return GNTST_general_error;
+    }
+
+    ol1e = *pl1e;
+
+    if ( unlikely(!UPDATE_ENTRY(l1, pl1e, ol1e, l1e_empty(),
+                                gl1mfn, curr, 0)) )
+    {
+        page_unlock(l1pg);
+        put_page(l1pg);
+        gdprintk(XENLOG_WARNING, "Cannot delete PTE entry at %p\n", pl1e);
+        pv_unmap_guest_l1e(pl1e);
+        return GNTST_general_error;
+    }
+
+    page_unlock(l1pg);
+    put_page(l1pg);
+    pv_unmap_guest_l1e(pl1e);
+
+    rc = replace_grant_va_mapping(addr, frame, ol1e, curr);
+    if ( rc )
+        put_page_from_l1e(ol1e, curr->domain);
+
+    return rc;
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
-- 
2.11.0


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