[Xen-devel] [RFC][v2][PATCH 12/14] hvmloader/pci: skip reserved ranges

[Tiejun Chen <tiejun.chen@xxxxxxxxx>]

When allocating mmio address for PCI bars, we need to make
sure they don't overlap with reserved regions.

Signed-off-by: Tiejun Chen <tiejun.chen@xxxxxxxxx>
---
 tools/firmware/hvmloader/pci.c | 36 ++++++++++++++++++++++++++++++++++--
 1 file changed, 34 insertions(+), 2 deletions(-)

diff --git a/tools/firmware/hvmloader/pci.c b/tools/firmware/hvmloader/pci.c
index 5ff87a7..98af568 100644
--- a/tools/firmware/hvmloader/pci.c
+++ b/tools/firmware/hvmloader/pci.c
@@ -59,8 +59,8 @@ void pci_setup(void)
         uint32_t bar_reg;
         uint64_t bar_sz;
     } *bars = (struct bars *)scratch_start;
-    unsigned int i, nr_bars = 0;
-    uint64_t mmio_hole_size = 0;
+    unsigned int i, j, nr_bars = 0;
+    uint64_t mmio_hole_size = 0, reserved_end, max_bar_sz = 0;
 
     const char *s;
     /*
@@ -226,6 +226,8 @@ void pci_setup(void)
             bars[i].devfn   = devfn;
             bars[i].bar_reg = bar_reg;
             bars[i].bar_sz  = bar_sz;
+            if ( bar_sz > max_bar_sz )
+                max_bar_sz = bar_sz;
 
             if ( ((bar_data & PCI_BASE_ADDRESS_SPACE) ==
                   PCI_BASE_ADDRESS_SPACE_MEMORY) ||
@@ -301,6 +303,21 @@ void pci_setup(void)
             pci_mem_start <<= 1;
     }
 
+    /* Relocate PCI memory that overlaps reserved space, like RDM. */
+    for ( j = 0; j < memory_map.nr_map ; j++ )
+    {
+        if ( memory_map.map[j].type != E820_RAM )
+        {
+            reserved_end = memory_map.map[j].addr + memory_map.map[j].size;
+            if ( check_overlap(pci_mem_start, pci_mem_end,
+                               memory_map.map[j].addr,
+                               memory_map.map[j].size) )
+                pci_mem_start -= memory_map.map[j].size >> PAGE_SHIFT;
+                pci_mem_start = (pci_mem_start + max_bar_sz - 1) &
+                                    ~(uint64_t)(max_bar_sz - 1);
+        }
+    }
+
     if ( mmio_total > (pci_mem_end - pci_mem_start) )
     {
         printf("Low MMIO hole not large enough for all devices,"
@@ -407,8 +424,23 @@ void pci_setup(void)
         }
 
         base = (resource->base  + bar_sz - 1) & ~(uint64_t)(bar_sz - 1);
+ reallocate_mmio:
         bar_data |= (uint32_t)base;
         bar_data_upper = (uint32_t)(base >> 32);
+        for ( j = 0; j < memory_map.nr_map ; j++ )
+        {
+            if ( memory_map.map[j].type != E820_RAM )
+            {
+                reserved_end = memory_map.map[j].addr + memory_map.map[j].size;
+                if ( check_overlap(base, bar_sz,
+                                   memory_map.map[j].addr,
+                                   memory_map.map[j].size) )
+                {
+                    base = (reserved_end  + bar_sz - 1) & ~(uint64_t)(bar_sz - 
1);
+                    goto reallocate_mmio;
+                }
+            }
+        }
         base += bar_sz;
 
         if ( (base < resource->base) || (base > resource->max) )
-- 
1.9.1


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