[Xen-devel] [PATCH V2 2/2] x86/mm: Make use of the default access param from xc_altp2m_create_view

[Alexandru Stefan ISAILA <aisaila@bitdefender.com>]

At this moment the default_access param from xc_altp2m_create_view is
not used.

This patch assigns default_access to p2m->default_access at the time of
initializing a new altp2m view.

Signed-off-by: Alexandru Isaila <aisaila@bitdefender.com>
Reviewed-by: Tamas K Lengyel <tamas@tklengyel.com>
Acked-by: George Dunlap <george.dunlap@citrix.com>
---
 xen/arch/x86/hvm/hvm.c            |  3 ++-
 xen/arch/x86/mm/p2m-ept.c         |  5 +++--
 xen/arch/x86/mm/p2m.c             | 31 ++++++++++++++++++++++++++-----
 xen/include/asm-x86/hvm/vmx/vmx.h |  3 ++-
 xen/include/asm-x86/p2m.h         |  3 ++-
 xen/include/public/hvm/hvm_op.h   |  2 --
 6 files changed, 35 insertions(+), 12 deletions(-)

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 66ed8b8e3e..84f836a5c9 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -4669,7 +4669,8 @@ static int do_altp2m_op(
     }
 
     case HVMOP_altp2m_create_p2m:
-        if ( !(rc = p2m_init_next_altp2m(d, &a.u.view.view)) )
+        if ( !(rc = p2m_init_next_altp2m(d, &a.u.view.view,
+                                         a.u.view.hvmmem_default_access)) )
             rc = __copy_to_guest(arg, &a, 1) ? -EFAULT : 0;
         break;
 
diff --git a/xen/arch/x86/mm/p2m-ept.c b/xen/arch/x86/mm/p2m-ept.c
index 220990f017..e62e749ec5 100644
--- a/xen/arch/x86/mm/p2m-ept.c
+++ b/xen/arch/x86/mm/p2m-ept.c
@@ -1345,13 +1345,14 @@ void setup_ept_dump(void)
     register_keyhandler('D', ept_dump_p2m_table, "dump VT-x EPT tables", 0);
 }
 
-void p2m_init_altp2m_ept(struct domain *d, unsigned int i)
+void p2m_init_altp2m_ept(struct domain *d, unsigned int i,
+                         p2m_access_t default_access)
 {
     struct p2m_domain *p2m = d->arch.altp2m_p2m[i];
     struct p2m_domain *hostp2m = p2m_get_hostp2m(d);
     struct ept_data *ept;
 
-    p2m->default_access = hostp2m->default_access;
+    p2m->default_access = default_access;
     p2m->domain = hostp2m->domain;
 
     p2m->global_logdirty = hostp2m->global_logdirty;
diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index 9e1335065d..e45a2c3c44 100644
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -2528,7 +2528,8 @@ void p2m_flush_altp2m(struct domain *d)
     altp2m_list_unlock(d);
 }
 
-static int p2m_activate_altp2m(struct domain *d, unsigned int idx)
+static int p2m_activate_altp2m(struct domain *d, unsigned int idx,
+                               p2m_access_t hvmmem_default_access)
 {
     struct p2m_domain *hostp2m, *p2m;
     int rc;
@@ -2554,7 +2555,7 @@ static int p2m_activate_altp2m(struct domain *d, unsigned int idx)
         goto out;
     }
 
-    p2m_init_altp2m_ept(d, idx);
+    p2m_init_altp2m_ept(d, idx, hvmmem_default_access);
 
  out:
     p2m_unlock(p2m);
@@ -2565,6 +2566,7 @@ static int p2m_activate_altp2m(struct domain *d, unsigned int idx)
 int p2m_init_altp2m_by_id(struct domain *d, unsigned int idx)
 {
     int rc = -EINVAL;
+    struct p2m_domain *hostp2m = p2m_get_hostp2m(d);
 
     if ( idx >= MAX_ALTP2M )
         return rc;
@@ -2572,17 +2574,36 @@ int p2m_init_altp2m_by_id(struct domain *d, unsigned int idx)
     altp2m_list_lock(d);
 
     if ( d->arch.altp2m_eptp[idx] == mfn_x(INVALID_MFN) )
-        rc = p2m_activate_altp2m(d, idx);
+        rc = p2m_activate_altp2m(d, idx, hostp2m->default_access);
 
     altp2m_list_unlock(d);
     return rc;
 }
 
-int p2m_init_next_altp2m(struct domain *d, uint16_t *idx)
+int p2m_init_next_altp2m(struct domain *d, uint16_t *idx,
+                         uint16_t hvmmem_default_access)
 {
     int rc = -EINVAL;
     unsigned int i;
 
+    static const p2m_access_t memaccess[] = {
+#define ACCESS(ac) [XENMEM_access_##ac] = p2m_access_##ac
+        ACCESS(n),
+        ACCESS(r),
+        ACCESS(w),
+        ACCESS(rw),
+        ACCESS(x),
+        ACCESS(rx),
+        ACCESS(wx),
+        ACCESS(rwx),
+        ACCESS(rx2rw),
+        ACCESS(n2rwx),
+#undef ACCESS
+    };
+
+    if ( hvmmem_default_access > XENMEM_access_default )
+        return rc;
+
     altp2m_list_lock(d);
 
     for ( i = 0; i < MAX_ALTP2M; i++ )
@@ -2590,7 +2611,7 @@ int p2m_init_next_altp2m(struct domain *d, uint16_t *idx)
         if ( d->arch.altp2m_eptp[i] != mfn_x(INVALID_MFN) )
             continue;
 
-        rc = p2m_activate_altp2m(d, i);
+        rc = p2m_activate_altp2m(d, i, memaccess[hvmmem_default_access]);
 
         if ( !rc )
             *idx = i;
diff --git a/xen/include/asm-x86/hvm/vmx/vmx.h b/xen/include/asm-x86/hvm/vmx/vmx.h
index ebaa74449b..a9601e8f7e 100644
--- a/xen/include/asm-x86/hvm/vmx/vmx.h
+++ b/xen/include/asm-x86/hvm/vmx/vmx.h
@@ -598,7 +598,8 @@ void ept_p2m_uninit(struct p2m_domain *p2m);
 void ept_walk_table(struct domain *d, unsigned long gfn);
 bool_t ept_handle_misconfig(uint64_t gpa);
 void setup_ept_dump(void);
-void p2m_init_altp2m_ept(struct domain *d, unsigned int i);
+void p2m_init_altp2m_ept(struct domain *d, unsigned int i,
+                         p2m_access_t default_access);
 /* Locate an alternate p2m by its EPTP */
 unsigned int p2m_find_altp2m_by_eptp(struct domain *d, uint64_t eptp);
 
diff --git a/xen/include/asm-x86/p2m.h b/xen/include/asm-x86/p2m.h
index 94285db1b4..321d5e70a8 100644
--- a/xen/include/asm-x86/p2m.h
+++ b/xen/include/asm-x86/p2m.h
@@ -884,7 +884,8 @@ bool p2m_altp2m_get_or_propagate(struct p2m_domain *ap2m, unsigned long gfn_l,
 int p2m_init_altp2m_by_id(struct domain *d, unsigned int idx);
 
 /* Find an available alternate p2m and make it valid */
-int p2m_init_next_altp2m(struct domain *d, uint16_t *idx);
+int p2m_init_next_altp2m(struct domain *d, uint16_t *idx,
+                         uint16_t hvmmem_default_access);
 
 /* Make a specific alternate p2m invalid */
 int p2m_destroy_altp2m_by_id(struct domain *d, unsigned int idx);
diff --git a/xen/include/public/hvm/hvm_op.h b/xen/include/public/hvm/hvm_op.h
index 9834ce0aea..fbe4b53d8d 100644
--- a/xen/include/public/hvm/hvm_op.h
+++ b/xen/include/public/hvm/hvm_op.h
@@ -242,8 +242,6 @@ DEFINE_XEN_GUEST_HANDLE(xen_hvm_altp2m_vcpu_disable_notify_t);
 struct xen_hvm_altp2m_view {
     /* IN/OUT variable */
     uint16_t view;
-    /* Create view only: default access type
-     * NOTE: currently ignored */
     uint16_t hvmmem_default_access; /* xenmem_access_t */
 };
 typedef struct xen_hvm_altp2m_view xen_hvm_altp2m_view_t;
-- 
2.17.1


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