commit 1e1da7a963007d03a4e0e9a9e0ff17990bb1608d
author Gerd Hoffmann <kraxel@redhat.com> Fri Apr 21 12:42:51 2023 +0200
committer Gerd Hoffmann <kraxel@redhat.com> Thu Aug 24 10:56:21 2023 +0200
tree c08db7a8850bec6e0323e2dc0ec57430461f176f
parent ecc51f211f3edd4fcc79d38af56cf84283e4d8b1

check for e820 conflict

Add support to check for overlaps with e820 entries.
In case the 64bit pci io window has conflicts move it down.

The only known case where this happens is AMD processors
with 1TB address space which has some space just below
1TB reserved for HT.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

src/e820map.c

diff --git a/src/e820map.c b/src/e820map.c
index 39445cf..c761e5e 100644
--- a/src/e820map.c
+++ b/src/e820map.c
@@ -150,3 +150,18 @@
 {
     dump_map();
 }
+
+int
+e820_is_used(u64 start, u64 size)
+{
+    int i;
+    for (i=0; i<e820_count; i++) {
+        struct e820entry *e = &e820_list[i];
+        if (start + size <= e->start)
+            continue;
+        if (start >= e->start + e->size)
+            continue;
+        return 1;
+    }
+    return 0;
+}

src/e820map.h

diff --git a/src/e820map.h b/src/e820map.h
index de8b523..07ce16e 100644
--- a/src/e820map.h
+++ b/src/e820map.h
@@ -18,6 +18,7 @@
 void e820_add(u64 start, u64 size, u32 type);
 void e820_remove(u64 start, u64 size);
 void e820_prepboot(void);
+int e820_is_used(u64 start, u64 size);
 
 // e820 map storage
 extern struct e820entry e820_list[];

src/fw/pciinit.c

diff --git a/src/fw/pciinit.c b/src/fw/pciinit.c
index b52bd1d..c7084f5 100644
--- a/src/fw/pciinit.c
+++ b/src/fw/pciinit.c
@@ -1140,6 +1140,8 @@
             if (r64_mem.base < top - size) {
                 r64_mem.base = top - size;
             }
+            if (e820_is_used(r64_mem.base, size))
+                r64_mem.base -= size;
         }
         r64_mem.base = ALIGN(r64_mem.base, align_mem);
         r64_mem.base = ALIGN(r64_mem.base, (1LL<<30));    // 1G hugepage