[PATCH v2 11/18] x86/pv: untie issuing FLUSH_ROOT_PGTBL from XPTI

[Roger Pau Monne <roger.pau@xxxxxxxxxx>]

The current logic gates issuing flush TLB requests with the FLUSH_ROOT_PGTBL
flag to XPTI being enabled.

In preparation for FLUSH_ROOT_PGTBL also being needed when not using XPTI,
untie it from the xpti domain boolean and instead introduce a new flush_root_pt
field.

No functional change intended, as flush_root_pt == xpti.

Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
---
 xen/arch/x86/include/asm/domain.h   | 2 ++
 xen/arch/x86/include/asm/flushtlb.h | 2 +-
 xen/arch/x86/mm.c                   | 2 +-
 xen/arch/x86/pv/domain.c            | 2 ++
 4 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/xen/arch/x86/include/asm/domain.h 
b/xen/arch/x86/include/asm/domain.h
index 7c143d2a6c46..5af414fa64ac 100644
--- a/xen/arch/x86/include/asm/domain.h
+++ b/xen/arch/x86/include/asm/domain.h
@@ -281,6 +281,8 @@ struct pv_domain
     bool pcid;
     /* Mitigate L1TF with shadow/crashing? */
     bool check_l1tf;
+    /* Issue FLUSH_ROOT_PGTBL for root page-table changes. */
+    bool flush_root_pt;
 
     /* map_domain_page() mapping cache. */
     struct mapcache_domain mapcache;
diff --git a/xen/arch/x86/include/asm/flushtlb.h 
b/xen/arch/x86/include/asm/flushtlb.h
index bb0ad58db49b..1b98d03decdc 100644
--- a/xen/arch/x86/include/asm/flushtlb.h
+++ b/xen/arch/x86/include/asm/flushtlb.h
@@ -177,7 +177,7 @@ void flush_area_mask(const cpumask_t *mask, const void *va,
 
 #define flush_root_pgtbl_domain(d)                                       \
 {                                                                        \
-    if ( is_pv_domain(d) && (d)->arch.pv.xpti )                          \
+    if ( is_pv_domain(d) && (d)->arch.pv.flush_root_pt )                 \
         flush_mask((d)->dirty_cpumask, FLUSH_ROOT_PGTBL);                \
 }
 
diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index c321f5723b04..49403196d56e 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -4178,7 +4178,7 @@ long do_mmu_update(
                                       cmd == MMU_PT_UPDATE_PRESERVE_AD, v);
                     if ( !rc )
                         flush_linear_pt = true;
-                    if ( !rc && pt_owner->arch.pv.xpti )
+                    if ( !rc && pt_owner->arch.pv.flush_root_pt )
                     {
                         bool local_in_use = false;
 
diff --git a/xen/arch/x86/pv/domain.c b/xen/arch/x86/pv/domain.c
index 534d2899100f..5bda168eadff 100644
--- a/xen/arch/x86/pv/domain.c
+++ b/xen/arch/x86/pv/domain.c
@@ -368,6 +368,8 @@ int pv_domain_initialise(struct domain *d)
 
     d->arch.ctxt_switch = &pv_csw;
 
+    d->arch.pv.flush_root_pt = d->arch.pv.xpti;
+
     if ( !is_pv_32bit_domain(d) && use_invpcid && cpu_has_pcid )
         switch ( ACCESS_ONCE(opt_pcid) )
         {
-- 
2.46.0