x86/pvh: reorder PVH dom0 iommu initialization

So that the iommu is initialized before populating the p2m, and
entries added get the corresponding iommu page table entries if
required. This requires splitting the current pvh_setup_p2m into two
different functions. One that crafts dom0 physmap and sets the paging
allocation, and another one that actually populates the p2m with RAM
regions.

Note that this allows to remove the special casing done for the low
1MB in hwdom_iommu_map.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Release-acked-by: Juergen Gross <jgross@suse.com>

diff --git a/xen/arch/x86/hvm/dom0_build.c b/xen/arch/x86/hvm/dom0_build.c
index a571d15c1344d29e33308b91af5355b56ae79f4e..aa599f09ef7615959eab34d7a2b423d2f738aa7c 100644 (file)
--- a/xen/arch/x86/hvm/dom0_build.c
+++ b/xen/arch/x86/hvm/dom0_build.c
@@ -409,14 +409,10 @@ static __init void pvh_setup_e820(struct domain *d, unsigned long nr_pages)
     ASSERT(cur_pages == nr_pages);
 }
 
-static int __init pvh_setup_p2m(struct domain *d)
+static void __init pvh_init_p2m(struct domain *d)
 {
-    struct vcpu *v = d->vcpu[0];
     unsigned long nr_pages = dom0_compute_nr_pages(d, NULL, 0);
-    unsigned int i;
-    int rc;
     bool preempted;
-#define MB1_PAGES PFN_DOWN(MB(1))
 
     pvh_setup_e820(d, nr_pages);
     do {
@@ -425,6 +421,14 @@ static int __init pvh_setup_p2m(struct domain *d)
                               &preempted);
         process_pending_softirqs();
     } while ( preempted );
+}
+
+static int __init pvh_populate_p2m(struct domain *d)
+{
+    struct vcpu *v = d->vcpu[0];
+    unsigned int i;
+    int rc;
+#define MB1_PAGES PFN_DOWN(MB(1))
 
     /*
      * Memory below 1MB is identity mapped initially. RAM regions are
@@ -1134,13 +1138,6 @@ int __init dom0_construct_pvh(struct domain *d, const module_t *image,
 
     printk(XENLOG_INFO "*** Building a PVH Dom%d ***\n", d->domain_id);
 
-    rc = pvh_setup_p2m(d);
-    if ( rc )
-    {
-        printk("Failed to setup Dom0 physical memory map\n");
-        return rc;
-    }
-
     /*
      * NB: MMCFG initialization needs to be performed before iommu
      * initialization so the iommu code can fetch the MMCFG regions used by the
@@ -1148,8 +1145,22 @@ int __init dom0_construct_pvh(struct domain *d, const module_t *image,
      */
     pvh_setup_mmcfg(d);
 
+    /*
+     * Craft dom0 physical memory map and set the paging allocation. This must
+     * be done before the iommu initializion, since iommu initialization code
+     * will likely add mappings required by devices to the p2m (ie: RMRRs).
+     */
+    pvh_init_p2m(d);
+
     iommu_hwdom_init(d);
 
+    rc = pvh_populate_p2m(d);
+    if ( rc )
+    {
+        printk("Failed to setup Dom0 physical memory map\n");
+        return rc;
+    }
+
     rc = pvh_load_kernel(d, image, image_headroom, initrd, bootstrap_map(image),
                          cmdline, &entry, &start_info);
     if ( rc )

diff --git a/xen/drivers/passthrough/x86/iommu.c b/xen/drivers/passthrough/x86/iommu.c
index a88ef9b18922de26735e136c5893e25ce272a697..42b1a1bbc3f3bdf8a8979ec58b2b517c500a7029 100644 (file)
--- a/xen/drivers/passthrough/x86/iommu.c
+++ b/xen/drivers/passthrough/x86/iommu.c
@@ -151,12 +151,7 @@ static bool __hwdom_init hwdom_iommu_map(const struct domain *d,
      * inclusive mapping additionally maps in every pfn up to 4GB except those
      * that fall in unusable ranges for PV Dom0.
      */
-    if ( (pfn > max_pfn && !mfn_valid(mfn)) || xen_in_range(pfn) ||
-         /*
-          * Ignore any address below 1MB, that's already identity mapped by the
-          * Dom0 builder for HVM.
-          */
-         (!d->domain_id && is_hvm_domain(d) && pfn < PFN_DOWN(MB(1))) )
+    if ( (pfn > max_pfn && !mfn_valid(mfn)) || xen_in_range(pfn) )
         return false;
 
     switch ( type = page_get_ram_type(mfn) )