# HG changeset patch
# User Keir Fraser <keir@xxxxxxx>
# Date 1286359219 -3600
# Node ID 02e199c96ece5d2853514a14ce7407fd8167ae47
# Parent 368957d8b063273d3bad38b122d15b5b8fda29ec
x86 hvm: Factor out hvm_map_guest_frame_{rw,ro} from hvm_map_entry
This allows us to map pages from guest physical addresses.
This will be used with nested virtualization.
Signed-off-by: Uwe Dannowski <Uwe.Dannowski@xxxxxxx>
Signed-off-by: Christoph Egger <Christoph.Egger@xxxxxxx>
Signed-off-by: Keir Fraser <keir@xxxxxxx>
---
xen/arch/x86/hvm/hvm.c | 99 +++++++++++++++++++++++++++---------------
xen/include/asm-x86/hvm/hvm.h | 4 +
2 files changed, 68 insertions(+), 35 deletions(-)
diff -r 368957d8b063 -r 02e199c96ece xen/arch/x86/hvm/hvm.c
--- a/xen/arch/x86/hvm/hvm.c Tue Oct 05 17:51:28 2010 +0100
+++ b/xen/arch/x86/hvm/hvm.c Wed Oct 06 11:00:19 2010 +0100
@@ -1356,55 +1356,84 @@ int hvm_virtual_to_linear_addr(
return 0;
}
+static void *__hvm_map_guest_frame(unsigned long gfn, bool_t writable)
+{
+ unsigned long mfn;
+ p2m_type_t p2mt;
+ struct p2m_domain *p2m = p2m_get_hostp2m(current->domain);
+
+ mfn = mfn_x(writable
+ ? gfn_to_mfn_unshare(p2m, gfn, &p2mt, 0)
+ : gfn_to_mfn(p2m, gfn, &p2mt));
+ if ( (p2m_is_shared(p2mt) && writable) || !p2m_is_ram(p2mt) )
+ return NULL;
+ if ( p2m_is_paging(p2mt) )
+ {
+ p2m_mem_paging_populate(p2m, gfn);
+ return NULL;
+ }
+
+ ASSERT(mfn_valid(mfn));
+
+ if ( writable )
+ paging_mark_dirty(current->domain, mfn);
+
+ return map_domain_page(mfn);
+}
+
+void *hvm_map_guest_frame_rw(unsigned long gfn)
+{
+ return __hvm_map_guest_frame(gfn, 1);
+}
+
+void *hvm_map_guest_frame_ro(unsigned long gfn)
+{
+ return __hvm_map_guest_frame(gfn, 0);
+}
+
+void hvm_unmap_guest_frame(void *p)
+{
+ if ( p )
+ unmap_domain_page(p);
+}
+
static void *hvm_map_entry(unsigned long va)
{
- unsigned long gfn, mfn;
- p2m_type_t p2mt;
+ unsigned long gfn;
uint32_t pfec;
- struct vcpu *v = current;
- struct p2m_domain *p2m = p2m_get_hostp2m(v->domain);
+ char *v;
if ( ((va & ~PAGE_MASK) + 8) > PAGE_SIZE )
{
gdprintk(XENLOG_ERR, "Descriptor table entry "
"straddles page boundary\n");
- domain_crash(current->domain);
- return NULL;
- }
-
- /* We're mapping on behalf of the segment-load logic, which might
- * write the accessed flags in the descriptors (in 32-bit mode), but
- * we still treat it as a kernel-mode read (i.e. no access checks). */
+ goto fail;
+ }
+
+ /*
+ * We're mapping on behalf of the segment-load logic, which might write
+ * the accessed flags in the descriptors (in 32-bit mode), but we still
+ * treat it as a kernel-mode read (i.e. no access checks).
+ */
pfec = PFEC_page_present;
gfn = paging_gva_to_gfn(current, va, &pfec);
- if ( pfec == PFEC_page_paged || pfec == PFEC_page_shared )
- return NULL;
- mfn = mfn_x(gfn_to_mfn_unshare(p2m, gfn, &p2mt, 0));
- if ( p2m_is_paging(p2mt) )
- {
- p2m_mem_paging_populate(p2m, gfn);
- return NULL;
- }
- if ( p2m_is_shared(p2mt) )
- return NULL;
- if ( !p2m_is_ram(p2mt) )
- {
- gdprintk(XENLOG_ERR, "Failed to look up descriptor table entry\n");
- domain_crash(current->domain);
- return NULL;
- }
-
- ASSERT(mfn_valid(mfn));
-
- paging_mark_dirty(current->domain, mfn);
-
- return (char *)map_domain_page(mfn) + (va & ~PAGE_MASK);
+ if ( (pfec == PFEC_page_paged) || (pfec == PFEC_page_shared) )
+ goto fail;
+
+ v = hvm_map_guest_frame_rw(gfn);
+ if ( v == NULL )
+ goto fail;
+
+ return v + (va & ~PAGE_MASK);
+
+ fail:
+ domain_crash(current->domain);
+ return NULL;
}
static void hvm_unmap_entry(void *p)
{
- if ( p )
- unmap_domain_page(p);
+ hvm_unmap_guest_frame(p);
}
static int hvm_load_segment_selector(
diff -r 368957d8b063 -r 02e199c96ece xen/include/asm-x86/hvm/hvm.h
--- a/xen/include/asm-x86/hvm/hvm.h Tue Oct 05 17:51:28 2010 +0100
+++ b/xen/include/asm-x86/hvm/hvm.h Wed Oct 06 11:00:19 2010 +0100
@@ -344,6 +344,10 @@ int hvm_virtual_to_linear_addr(
unsigned int addr_size,
unsigned long *linear_addr);
+void *hvm_map_guest_frame_rw(unsigned long gfn);
+void *hvm_map_guest_frame_ro(unsigned long gfn);
+void hvm_unmap_guest_frame(void *p);
+
static inline void hvm_set_info_guest(struct vcpu *v)
{
if ( hvm_funcs.set_info_guest )
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