From: Keir Fraser <keir.fraser@citrix.com>
Date: Wed, 2 Dec 2009 18:46:14 +0000 (+0000)
Subject: x86 hvm: fix up the unified HAP nested-pagefault handler.
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~12974
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=40e9da38fd8c75147fb9205c6fb6cf6a597d1127;p=xen.git

x86 hvm: fix up the unified HAP nested-pagefault handler.
A guest PFN may have been marked dirty and switched to p2m_ram_rw by
another CPU between the VMEXIT and lookup in this handler, so
we can't just check for p2m_ram_logdirty.  Also, handle_mmio
doesn't handle passthrough MMIO.

Signed-off-by: Tim Deegan <Tim.Deegan@citrix.com>
---

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index ca567638ae..42121fec80 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -927,7 +927,7 @@ bool_t hvm_hap_nested_page_fault(unsigned long gfn)
      * If this GFN is emulated MMIO or marked as read-only, pass the fault
      * to the mmio handler.
      */
-    if ( p2m_is_mmio(p2mt) || (p2mt == p2m_ram_ro) )
+    if ( (p2mt == p2m_mmio_dm) || (p2mt == p2m_ram_ro) )
     {
         if ( !handle_mmio() )
             hvm_inject_exception(TRAP_gp_fault, 0, 0);
@@ -935,7 +935,8 @@ bool_t hvm_hap_nested_page_fault(unsigned long gfn)
     }
 
     /* Log-dirty: mark the page dirty and let the guest write it again */
-    if ( p2mt == p2m_ram_logdirty )
+    if ( paging_mode_log_dirty(current->domain)
+         && p2m_is_ram(p2mt) && (p2mt != p2m_ram_ro) )
     {
         paging_mark_dirty(current->domain, mfn_x(mfn));
         p2m_change_type(current->domain, gfn, p2m_ram_logdirty, p2m_ram_rw);