@@ -3028,12 +3028,22 @@ static int vmx_alloc_vlapic_mapping(struct domain *d)
if ( !cpu_has_vmx_virtualize_apic_accesses )
return 0;
- pg = alloc_domheap_page(d, MEMF_no_owner);
+ pg = alloc_domheap_page(d, MEMF_no_refcount);
if ( !pg )
return -ENOMEM;
+
+ if ( !get_page_and_type(pg, d, PGT_writable_page) )
+ {
+ /*
+ * The domain can't possibly know about this page yet, so failure
+ * here is a clear indication of something fishy going on.
+ */
+ domain_crash(d);
+ return -ENODATA;
+ }
+
mfn = page_to_mfn(pg);
clear_domain_page(mfn);
- share_xen_page_with_guest(pg, d, SHARE_rw);
d->arch.hvm.vmx.apic_access_mfn = mfn;
return set_mmio_p2m_entry(d, paddr_to_pfn(APIC_DEFAULT_PHYS_BASE), mfn,
@@ -3047,7 +3057,12 @@ static void vmx_free_vlapic_mapping(struct domain *d)
d->arch.hvm.vmx.apic_access_mfn = _mfn(0);
if ( !mfn_eq(mfn, _mfn(0)) )
- free_shared_domheap_page(mfn_to_page(mfn));
+ {
+ struct page_info *pg = mfn_to_page(mfn);
+
+ put_page_alloc_ref(pg);
+ put_page_and_type(pg);
+ }
}
static void vmx_install_vlapic_mapping(struct vcpu *v)
@@ -496,16 +496,6 @@ void share_xen_page_with_guest(struct page_info *page, struct domain *d,
spin_unlock(&d->page_alloc_lock);
}
-void free_shared_domheap_page(struct page_info *page)
-{
- put_page_alloc_ref(page);
- if ( !test_and_clear_bit(_PGC_xen_heap, &page->count_info) )
- ASSERT_UNREACHABLE();
- page->u.inuse.type_info = 0;
- page_set_owner(page, NULL);
- free_domheap_page(page);
-}
-
void make_cr3(struct vcpu *v, mfn_t mfn)
{
struct domain *d = v->domain;
@@ -320,8 +320,6 @@ struct page_info
#define maddr_get_owner(ma) (page_get_owner(maddr_to_page((ma))))
-extern void free_shared_domheap_page(struct page_info *page);
-
#define frame_table ((struct page_info *)FRAMETABLE_VIRT_START)
extern unsigned long max_page;
extern unsigned long total_pages;
vmx_alloc_vlapic_mapping() currently contains some very odd looking code that allocates a MEMF_no_owner domheap page and then shares with the guest as if it were a xenheap page. This then requires vmx_free_vlapic_mapping() to call a special function in the mm code: free_shared_domheap_page(). By using a MEMF_no_refcount domheap page instead, the odd looking code in vmx_alloc_vlapic_mapping() can simply use get_page_and_type() to set up a writable mapping before insertion in the P2M and vmx_free_vlapic_mapping() can simply release the page using put_page_alloc_ref() followed by put_page_and_type(). This then allows free_shared_domheap_page() to be purged. Signed-off-by: Paul Durrant <pdurrant@amazon.com> --- Cc: Jun Nakajima <jun.nakajima@intel.com> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Jan Beulich <jbeulich@suse.com> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: Wei Liu <wl@xen.org> Cc: "Roger Pau Monné" <roger.pau@citrix.com> v4: - Use a MEMF_no_refcount page rather than a 'normal' page v2: - Set an initial value for max_pages rather than avoiding the check in assign_pages() - Make domain_destroy() optional --- xen/arch/x86/hvm/vmx/vmx.c | 21 ++++++++++++++++++--- xen/arch/x86/mm.c | 10 ---------- xen/include/asm-x86/mm.h | 2 -- 3 files changed, 18 insertions(+), 15 deletions(-)