[xen master] x86/shadow: further correct MMIO handling in _sh_propagate()

[patchbot@xxxxxxx]

commit 1d99732f2b092173d8600fa818aee3fa51046bb0
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Fri Jan 20 09:20:26 2023 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Fri Jan 20 09:20:26 2023 +0100

    x86/shadow: further correct MMIO handling in _sh_propagate()
    
    While c61a6f74f80e ("x86: enforce consistent cachability of MMIO
    mappings") correctly converted one !mfn_valid() check there, two others
    were wrongly left untouched: Both cachability control and log-dirty
    tracking ought to be uniformly handled/excluded for all (non-)MMIO
    ranges, not just ones qualifiable by mfn_valid().
    
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Acked-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
 xen/arch/x86/mm/shadow/multi.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/xen/arch/x86/mm/shadow/multi.c b/xen/arch/x86/mm/shadow/multi.c
index eb90bf2b15..98c0b7302a 100644
--- a/xen/arch/x86/mm/shadow/multi.c
+++ b/xen/arch/x86/mm/shadow/multi.c
@@ -550,8 +550,7 @@ _sh_propagate(struct vcpu *v,
      * caching attributes in the shadows to match what was asked for.
      */
     if ( (level == 1) && is_hvm_domain(d) &&
-         (!mfn_valid(target_mfn) ||
-          !is_special_page(mfn_to_page(target_mfn))) )
+         (mmio_mfn || !is_special_page(mfn_to_page(target_mfn))) )
     {
         int type;
 
@@ -662,8 +661,7 @@ _sh_propagate(struct vcpu *v,
      * (We handle log-dirty entirely inside the shadow code, without using the
      * p2m_ram_logdirty p2m type: only HAP uses that.)
      */
-    if ( level == 1 && unlikely(shadow_mode_log_dirty(d)) &&
-         mfn_valid(target_mfn) )
+    if ( level == 1 && unlikely(shadow_mode_log_dirty(d)) && !mmio_mfn )
     {
         if ( ft & FETCH_TYPE_WRITE )
             paging_mark_dirty(d, target_mfn);
--
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