Revert "xen/e820: Coalesce the PVH release/populate logic in the generic case."

This reverts commit f825f5f66cbb15429ec549ad745dd546b22640a6
as it is causing with PVH the following problem:

(XEN) vmx_hybrid.c:710:d0 Dom:0 EPT violation 0x181 (r--/---), gpa 0x000000bf421e1c, mfn 0xffffffffffffffff, type 4.
(XEN) p2m-ept.c:642:d0 Walking EPT tables for domain 0 gfn bf421
(XEN) p2m-ept.c:648:d0  gfn exceeds max_mapped_pfn 4b062
(XEN) vmx_hybrid.c:717:d0  --- GLA 0xffffffffff477e1c

The reason being:
xen_set_identity_and_release_chunk():
NEW : > for (pfn = start_pfn; pfn <= max_pfn_mapped && pfn < end_pfn; pfn++) {

xen_pvh_identity_map_chunk():
OLD: for (pfn = start_pfn; pfn < end_pfn; pfn++)

IOW, for PVH we need to avoid testing for max_pfn_mapped, as we are
mapping the entire IO space.

So lets revert it for right now, and come back to this later.

Reported-and-Tested-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 78c562251283ced0a8f588cf6a6869e2a59f8771..8cce47b98d5efe9435ba4432e0bf9ae51d9ba7e9 100644 (file)
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -114,15 +114,9 @@ static unsigned long __init xen_do_chunk(unsigned long start,
 
                if (release) {
                        /* Make sure pfn exists to start with */
-                       if (mfn == INVALID_P2M_ENTRY || (!xlated_phys && (mfn_to_pfn(mfn) != pfn)))
+                       if (mfn == INVALID_P2M_ENTRY || mfn_to_pfn(mfn) != pfn)
                                continue;
                        frame = mfn;
-                       /* The hypercall PHYSDEVOP_map_iomem to release memory has already
-                        * happend, so we just do a nop here. */
-                       if (xlated_phys) {
-                               len++;
-                               continue;
-                       }
                } else {
                        if (!xlated_phys && mfn != INVALID_P2M_ENTRY)
                                continue;
@@ -225,24 +219,15 @@ static void __init xen_set_identity_and_release_chunk(
 {
        unsigned long pfn;
 
-       /* For PVH, the pfns [0..MAX] are mapped to mfn's in the EPT/NPT. The mfns
-        * are released as part of this 1:1 mapping hypercall back to the dom heap.
-        * Also, we map the entire IO space, ie, beyond max_pfn_mapped.
-        */
-       int xlated_phys = xen_feature(XENFEAT_auto_translated_physmap);
-
        /*
         * If the PFNs are currently mapped, the VA mapping also needs
         * to be updated to be 1:1.
         */
-       for (pfn = start_pfn; pfn <= max_pfn_mapped && pfn < end_pfn; pfn++) {
-               if (xlated_phys)
-                       xen_set_clr_mmio_pvh_pte(pfn, pfn, 1 /* one pfn */, 1 /* add mapping */);
-               else
-                       (void)HYPERVISOR_update_va_mapping(
-                               (unsigned long)__va(pfn << PAGE_SHIFT),
-                               mfn_pte(pfn, PAGE_KERNEL_IO), 0);
-       }
+       for (pfn = start_pfn; pfn <= max_pfn_mapped && pfn < end_pfn; pfn++)
+               (void)HYPERVISOR_update_va_mapping(
+                       (unsigned long)__va(pfn << PAGE_SHIFT),
+                       mfn_pte(pfn, PAGE_KERNEL_IO), 0);
+
        if (start_pfn < nr_pages)
                *released += xen_release_chunk(
                        start_pfn, min(end_pfn, nr_pages));
@@ -250,6 +235,27 @@ static void __init xen_set_identity_and_release_chunk(
        *identity += set_phys_range_identity(start_pfn, end_pfn);
 }
 
+/* For PVH, the pfns [0..MAX] are mapped to mfn's in the EPT/NPT. The mfns
+ * are released as part of this 1:1 mapping hypercall back to the dom heap.
+ * Also, we map the entire IO space, ie, beyond max_pfn_mapped.
+ */
+static void __init xen_pvh_identity_map_chunk(unsigned long start_pfn,
+               unsigned long end_pfn, unsigned long *released,
+               unsigned long *identity, unsigned long max_pfn)
+{
+       unsigned long pfn;
+       int numpfns = 1, add_mapping = 1;
+
+       for (pfn = start_pfn; pfn < end_pfn; pfn++)
+               xen_set_clr_mmio_pvh_pte(pfn, pfn, numpfns, add_mapping);
+
+       if (start_pfn <= max_pfn) {
+               unsigned long end = min(max_pfn_mapped, end_pfn);
+               *released += end - start_pfn;
+       }
+       *identity += end_pfn - start_pfn;
+}
+
 static unsigned long __init xen_set_identity_and_release(
        const struct e820entry *list, size_t map_size, unsigned long nr_pages)
 {
@@ -258,6 +264,7 @@ static unsigned long __init xen_set_identity_and_release(
        unsigned long identity = 0;
        const struct e820entry *entry;
        int i;
+       int xlated_phys = xen_feature(XENFEAT_auto_translated_physmap);
 
        /*
         * Combine non-RAM regions and gaps until a RAM region (or the
@@ -279,10 +286,17 @@ static unsigned long __init xen_set_identity_and_release(
                        if (entry->type == E820_RAM)
                                end_pfn = PFN_UP(entry->addr);
 
-                       if (start_pfn < end_pfn)
-                               xen_set_identity_and_release_chunk(
+                       if (start_pfn < end_pfn) {
+                               if (xlated_phys) {
+                                       xen_pvh_identity_map_chunk(start_pfn,
+                                               end_pfn, &released, &identity,
+                                               nr_pages);
+                               } else {
+                                       xen_set_identity_and_release_chunk(
                                                start_pfn, end_pfn, nr_pages,
                                                &released, &identity);
+                               }
+                       }
                        start = end;
                }
        }