From: Xiong Zhang <xiong.y.zhang@intel.com>
Date: Mon, 28 Aug 2017 08:51:24 +0000 (+0200)
Subject: hvmloader: use base instead of pci_mem_start for find_next_rmrr()
X-Git-Tag: archive/raspbian/4.11.1-1+rpi1~1^2~66^2~1557
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=ecc607b1851bc27140090da4d6124fd00090ec2b;p=xen.git

hvmloader: use base instead of pci_mem_start for find_next_rmrr()

find_next_rmrr(base) is used to find the lowest RMRR ending above base
but below 4G. Current method couldn't cover the following situation:
a. two rmrr exist, small gap between them
b. pci_mem_start and mem_resource.base is below the first rmrr.base
c. find_next_rmrr(pci_mem_start) will find the first rmrr
d. After aligning mem_resource.base to bar size,
   first_rmrr.end < new_base < second_rmrr.base and
   new_base + bar_sz > second_rmrr.base.
   So the new bar will overlap with the second rmrr and doesn't overlap
with the first rmrr.
But the next_rmrr point to the first rmrr, then check_overlap() couldn't
find the overlap. Finally assign a wrong address to bar.

This patch using aligned new base to find the next rmrr, could fix the
above case and find all the overlapped rmrr with new base.

Signed-off-by: Xiong Zhang <xiong.y.zhang@intel.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
---

diff --git a/tools/firmware/hvmloader/pci.c b/tools/firmware/hvmloader/pci.c
index 4eb1a31733..9543e5aaf2 100644
--- a/tools/firmware/hvmloader/pci.c
+++ b/tools/firmware/hvmloader/pci.c
@@ -84,7 +84,6 @@ void pci_setup(void)
     uint32_t vga_devfn = 256;
     uint16_t class, vendor_id, device_id;
     unsigned int bar, pin, link, isa_irq;
-    int next_rmrr;
 
     /* Resources assignable to PCI devices via BARs. */
     struct resource {
@@ -403,8 +402,6 @@ void pci_setup(void)
     io_resource.base = 0xc000;
     io_resource.max = 0x10000;
 
-    next_rmrr = find_next_rmrr(pci_mem_start);
-
     /* Assign iomem and ioport resources in descending order of size. */
     for ( i = 0; i < nr_bars; i++ )
     {
@@ -462,15 +459,20 @@ void pci_setup(void)
         base = (resource->base  + bar_sz - 1) & ~(uint64_t)(bar_sz - 1);
 
         /* If we're using mem_resource, check for RMRR conflicts. */
-        while ( resource == &mem_resource &&
-                next_rmrr >= 0 &&
-                check_overlap(base, bar_sz,
+        if ( resource == &mem_resource)
+        {
+            int next_rmrr = find_next_rmrr(base);
+
+            while ( next_rmrr >= 0 &&
+                    check_overlap(base, bar_sz,
                               memory_map.map[next_rmrr].addr,
                               memory_map.map[next_rmrr].size) )
-        {
-            base = memory_map.map[next_rmrr].addr + memory_map.map[next_rmrr].size;
-            base = (base + bar_sz - 1) & ~(bar_sz - 1);
-            next_rmrr = find_next_rmrr(base);
+            {
+                base = memory_map.map[next_rmrr].addr +
+                       memory_map.map[next_rmrr].size;
+                base = (base + bar_sz - 1) & ~(bar_sz - 1);
+                next_rmrr = find_next_rmrr(base);
+            }
         }
 
         bar_data |= (uint32_t)base;