[RFC 1/4] HVM x86 deprivileged mode: Page allocation helper

[Ben Catterall <Ben.Catterall@citrix.com>]

This allocation function is used by the deprivileged mode initialisation code
to allocate pages for the new page table mappings and page frames on the HAP
page heap.

Signed-off-by: Ben Catterall <Ben.Catterall@citrix.com>
---
 xen/arch/x86/mm/hap/hap.c    | 23 +++++++++++++++++++++++
 xen/include/asm-x86/domain.h |  1 +
 xen/include/asm-x86/hap.h    |  5 +++++
 3 files changed, 29 insertions(+)

diff --git a/xen/arch/x86/mm/hap/hap.c b/xen/arch/x86/mm/hap/hap.c
index d375c4d..593cba7 100644
--- a/xen/arch/x86/mm/hap/hap.c
+++ b/xen/arch/x86/mm/hap/hap.c
@@ -844,6 +844,29 @@ static const struct paging_mode hap_paging_long_mode = {
     .guest_levels           = 4
 };
 
+/************************************************/
+/*               HAP HVM functions              */
+/************************************************/
+struct page_info *hvm_alloc_page(struct domain *d)
+{
+    struct page_info *pg;
+
+    if( (pg = hap_alloc(d)) == NULL )
+    {
+        HAP_ERROR("HVM: Out of memory allocating HVM page\n");
+        domain_crash(d);
+        return NULL;
+    }
+
+    ASSERT(paging_locked_by_me(d));
+
+    /* Track our used pages */
+    page_list_add(pg, &d->arch.paging.hap.hvmlist);
+
+    return pg;
+}
+
+
 /*
  * Local variables:
  * mode: C
diff --git a/xen/include/asm-x86/domain.h b/xen/include/asm-x86/domain.h
index 0fce09e..c46a31a 100644
--- a/xen/include/asm-x86/domain.h
+++ b/xen/include/asm-x86/domain.h
@@ -154,6 +154,7 @@ struct shadow_vcpu {
 /************************************************/
 struct hap_domain {
     struct page_list_head freelist;
+    struct page_list_head hvmlist;  /* HVM usermode page allocation */
     unsigned int      total_pages;  /* number of pages allocated */
     unsigned int      free_pages;   /* number of pages on freelists */
     unsigned int      p2m_pages;    /* number of pages allocates to p2m */
diff --git a/xen/include/asm-x86/hap.h b/xen/include/asm-x86/hap.h
index bd87481..0432eb5 100644
--- a/xen/include/asm-x86/hap.h
+++ b/xen/include/asm-x86/hap.h
@@ -48,6 +48,11 @@ int   hap_track_dirty_vram(struct domain *d,
 extern const struct paging_mode *hap_paging_get_mode(struct vcpu *);
 void hap_set_alloc_for_pvh_dom0(struct domain *d, unsigned long num_pages);
 
+/************************************************/
+/*               hap HVM functions              */
+/************************************************/
+
+struct page_info *hvm_alloc_page(struct domain *d);
 #endif /* XEN_HAP_H */
 
 /*
-- 
2.1.4