[PATCH v3 1/2] x86: add p2m_mmio_write_dm

[Wei Ye <wei.ye@intel.com>]

Add an new p2m type p2m_mmio_write_dm. Page of this type is read
only, and write will go to the device model for emulation just like
a mmio.

Signed-off-by: Wei Ye <wei.ye@intel.com>
---
 xen/arch/x86/hvm/hvm.c    |    3 ++-
 xen/arch/x86/mm/p2m-ept.c |    1 +
 xen/arch/x86/mm/p2m-pt.c  |    1 +
 xen/include/asm-x86/p2m.h |    1 +
 4 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 17ff011..adc0f93 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -2739,7 +2739,8 @@ int hvm_hap_nested_page_fault(paddr_t gpa,
      * to the mmio handler.
      */
     if ( (p2mt == p2m_mmio_dm) || 
-         (access_w && (p2mt == p2m_ram_ro)) )
+         (access_w && ((p2mt == p2m_ram_ro) ||
+         (p2mt == p2m_mmio_write_dm))) )
     {
         put_gfn(p2m->domain, gfn);
 
diff --git a/xen/arch/x86/mm/p2m-ept.c b/xen/arch/x86/mm/p2m-ept.c
index 15c6e83..e21a92d 100644
--- a/xen/arch/x86/mm/p2m-ept.c
+++ b/xen/arch/x86/mm/p2m-ept.c
@@ -136,6 +136,7 @@ static void ept_p2m_type_to_flags(ept_entry_t *entry, p2m_type_t type, p2m_acces
             entry->x = 0;
             break;
         case p2m_grant_map_ro:
+        case p2m_mmio_write_dm:
             entry->r = 1;
             entry->w = entry->x = 0;
             break;
diff --git a/xen/arch/x86/mm/p2m-pt.c b/xen/arch/x86/mm/p2m-pt.c
index 085ab6f..6a18606 100644
--- a/xen/arch/x86/mm/p2m-pt.c
+++ b/xen/arch/x86/mm/p2m-pt.c
@@ -94,6 +94,7 @@ static unsigned long p2m_type_to_flags(p2m_type_t t, mfn_t mfn)
     default:
         return flags | _PAGE_NX_BIT;
     case p2m_grant_map_ro:
+    case p2m_mmio_write_dm:
         return flags | P2M_BASE_FLAGS | _PAGE_NX_BIT;
     case p2m_ram_ro:
     case p2m_ram_logdirty:
diff --git a/xen/include/asm-x86/p2m.h b/xen/include/asm-x86/p2m.h
index 0ddbadb..523c7a9 100644
--- a/xen/include/asm-x86/p2m.h
+++ b/xen/include/asm-x86/p2m.h
@@ -71,6 +71,7 @@ typedef enum {
     p2m_ram_shared = 12,          /* Shared or sharable memory */
     p2m_ram_broken = 13,          /* Broken page, access cause domain crash */
     p2m_map_foreign  = 14,        /* ram pages from foreign domain */
+    p2m_mmio_write_dm = 15,       /* Read-only; write go to the device model */
 } p2m_type_t;
 
 /*
-- 
1.7.9.5