[Xen-devel] [v7][RFC][PATCH 05/13] hvmloader/mmio: reconcile guest mmio with reserved device memory

[Tiejun Chen <tiejun.chen@xxxxxxxxx>]

We need to make sure all mmio allocation don't overlap
any rdm, reserved device memory. Here we just skip
all reserved device memory range in mmio space.

Signed-off-by: Tiejun Chen <tiejun.chen@xxxxxxxxx>
---
 tools/firmware/hvmloader/pci.c | 68 +++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 67 insertions(+), 1 deletion(-)

diff --git a/tools/firmware/hvmloader/pci.c b/tools/firmware/hvmloader/pci.c
index 3712988..e26481c 100644
--- a/tools/firmware/hvmloader/pci.c
+++ b/tools/firmware/hvmloader/pci.c
@@ -37,6 +37,44 @@ uint64_t pci_hi_mem_start = 0, pci_hi_mem_end = 0;
 enum virtual_vga virtual_vga = VGA_none;
 unsigned long igd_opregion_pgbase = 0;
 
+unsigned int need_skip_rmrr = 0;
+
+/*
+ * Check whether there exists mmio hole in the specified memory range.
+ * Returns 1 if exists, else returns 0.
+ */
+static int check_mmio_hole_confliction(uint64_t start, uint64_t memsize,
+                           uint64_t mmio_start, uint64_t mmio_size)
+{
+    if ( start + memsize <= mmio_start || start >= mmio_start + mmio_size )
+        return 0;
+    else
+        return 1;
+}
+
+static int check_reserved_device_memory_map(uint64_t mmio_base,
+                                            uint64_t mmio_max)
+{
+    uint32_t i = 0;
+    uint64_t rdm_start, rdm_end;
+    int nr_entries = -1;
+
+    nr_entries = hvm_get_reserved_device_memory_map();
+
+    for ( i = 0; i < nr_entries; i++ )
+    {
+        rdm_start = rdm_map[i].start_pfn << PAGE_SHIFT;
+        rdm_end = rdm_start + (rdm_map[i].nr_pages << PAGE_SHIFT);
+        if ( check_mmio_hole_confliction(rdm_start, (rdm_end - rdm_start),
+                                         mmio_base, mmio_max - mmio_base) )
+        {
+            need_skip_rmrr++;
+        }
+    }
+
+    return nr_entries;
+}
+
 void pci_setup(void)
 {
     uint8_t is_64bar, using_64bar, bar64_relocate = 0;
@@ -58,7 +96,9 @@ void pci_setup(void)
         uint32_t bar_reg;
         uint64_t bar_sz;
     } *bars = (struct bars *)scratch_start;
-    unsigned int i, nr_bars = 0;
+    unsigned int i, j, nr_bars = 0;
+    int nr_entries = 0;
+    uint64_t rdm_start, rdm_end;
 
     const char *s;
     /*
@@ -309,6 +349,14 @@ void pci_setup(void)
     io_resource.base = 0xc000;
     io_resource.max = 0x10000;
 
+    /* Check low mmio range. */
+    nr_entries = check_reserved_device_memory_map(mem_resource.base,
+                                                  mem_resource.max);
+    /* Check high mmio range. */
+    if ( nr_entries > 0 )
+        nr_entries = check_reserved_device_memory_map(high_mem_resource.base,
+                                                      high_mem_resource.max);
+
     /* Assign iomem and ioport resources in descending order of size. */
     for ( i = 0; i < nr_bars; i++ )
     {
@@ -363,11 +411,29 @@ void pci_setup(void)
             bar_data &= ~PCI_BASE_ADDRESS_IO_MASK;
         }
 
+ reallocate_mmio:
         base = (resource->base  + bar_sz - 1) & ~(uint64_t)(bar_sz - 1);
         bar_data |= (uint32_t)base;
         bar_data_upper = (uint32_t)(base >> 32);
         base += bar_sz;
 
+        if ( need_skip_rmrr )
+        {
+            for ( j = 0; j < nr_entries; j++ )
+            {
+                rdm_start = rdm_map[j].start_pfn << PAGE_SHIFT;
+                rdm_end = rdm_start + (rdm_map[j].nr_pages << PAGE_SHIFT);
+                if ( check_mmio_hole_confliction(rdm_start,
+                                                 (rdm_end - rdm_start),
+                                                 base, bar_sz) )
+                {
+                    resource->base = rdm_end;
+                    need_skip_rmrr--;
+                    goto reallocate_mmio;
+                }
+            }
+        }
+
         if ( (base < resource->base) || (base > resource->max) )
         {
             printf("pci dev %02x:%x bar %02x size "PRIllx": no space for "
-- 
1.9.1


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