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1commit 8845b72377a42443b249360b9cd3d6f1e8cfb097
2Author: Alexander Graf <agraf@suse.de>
3Date:   Thu Dec 17 16:04:44 2009 +0100
4
5    Enable non page boundary BAR device assignment
6
7    While trying to get device passthrough working with an emulex hba, kvm
8    refused to pass it through because it has a BAR of 256 bytes:
9
10            Region 0: Memory at d2100000 (64-bit, non-prefetchable) [size=4K]
11            Region 2: Memory at d2101000 (64-bit, non-prefetchable) [size=256]
12            Region 4: I/O ports at b100 [size=256]
13
14    Since the page boundary is an arbitrary optimization to allow 1:1 mapping of
15    physical to virtual addresses, we can still take the old MMIO callback route.
16
17    So let's add a second code path that allows for size & 0xFFF != 0 sized regions
18    by looping it through userspace.
19
20    I verified that it works by passing through an e1000 with this additional patch
21    applied and the card acted the same way it did without this patch:
22
23                 map_func = assigned_dev_iomem_map;
24    -            if (cur_region->size & 0xFFF) {
25    +            if (i != PCI_ROM_SLOT){
26                     fprintf(stderr, "PCI region %d at address 0x%llx "
27
28    Signed-off-by: Alexander Graf <agraf@suse.de>
29    Signed-off-by: Avi Kivity <avi@redhat.com>
30
31diff --git a/hw/device-assignment.c b/hw/device-assignment.c
32index 5422e9a..c99d986 100644
33--- a/hw/device-assignment.c
34+++ b/hw/device-assignment.c
35@@ -158,6 +158,105 @@ static uint32_t assigned_dev_ioport_readl(void *opaque, uint32_t addr)
36     return assigned_dev_ioport_rw(opaque, addr, 4, NULL);
37 }
38
39+static uint32_t slow_bar_readb(void *opaque, target_phys_addr_t addr)
40+{
41+    AssignedDevRegion *d = opaque;
42+    uint8_t *in = d->u.r_virtbase + addr;
43+    uint32_t r;
44+
45+    r = *in;
46+    DEBUG("slow_bar_readl addr=0x" TARGET_FMT_plx " val=0x%08x\n", addr, r);
47+
48+    return r;
49+}
50+
51+static uint32_t slow_bar_readw(void *opaque, target_phys_addr_t addr)
52+{
53+    AssignedDevRegion *d = opaque;
54+    uint16_t *in = d->u.r_virtbase + addr;
55+    uint32_t r;
56+
57+    r = *in;
58+    DEBUG("slow_bar_readl addr=0x" TARGET_FMT_plx " val=0x%08x\n", addr, r);
59+
60+    return r;
61+}
62+
63+static uint32_t slow_bar_readl(void *opaque, target_phys_addr_t addr)
64+{
65+    AssignedDevRegion *d = opaque;
66+    uint32_t *in = d->u.r_virtbase + addr;
67+    uint32_t r;
68+
69+    r = *in;
70+    DEBUG("slow_bar_readl addr=0x" TARGET_FMT_plx " val=0x%08x\n", addr, r);
71+
72+    return r;
73+}
74+
75+static void slow_bar_writeb(void *opaque, target_phys_addr_t addr, uint32_t val)
76+{
77+    AssignedDevRegion *d = opaque;
78+    uint8_t *out = d->u.r_virtbase + addr;
79+
80+    DEBUG("slow_bar_writeb addr=0x" TARGET_FMT_plx " val=0x%02x\n", addr, val);
81+    *out = val;
82+}
83+
84+static void slow_bar_writew(void *opaque, target_phys_addr_t addr, uint32_t val)
85+{
86+    AssignedDevRegion *d = opaque;
87+    uint16_t *out = d->u.r_virtbase + addr;
88+
89+    DEBUG("slow_bar_writew addr=0x" TARGET_FMT_plx " val=0x%04x\n", addr, val);
90+    *out = val;
91+}
92+
93+static void slow_bar_writel(void *opaque, target_phys_addr_t addr, uint32_t val)
94+{
95+    AssignedDevRegion *d = opaque;
96+    uint32_t *out = d->u.r_virtbase + addr;
97+
98+    DEBUG("slow_bar_writel addr=0x" TARGET_FMT_plx " val=0x%08x\n", addr, val);
99+    *out = val;
100+}
101+
102+static CPUWriteMemoryFunc * const slow_bar_write[] = {
103+    &slow_bar_writeb,
104+    &slow_bar_writew,
105+    &slow_bar_writel
106+};
107+
108+static CPUReadMemoryFunc * const slow_bar_read[] = {
109+    &slow_bar_readb,
110+    &slow_bar_readw,
111+    &slow_bar_readl
112+};
113+
114+static void assigned_dev_iomem_map_slow(PCIDevice *pci_dev, int region_num,
115+                                        pcibus_t e_phys, pcibus_t e_size,
116+                                        int type)
117+{
118+    AssignedDevice *r_dev = container_of(pci_dev, AssignedDevice, dev);
119+    AssignedDevRegion *region = &r_dev->v_addrs[region_num];
120+    PCIRegion *real_region = &r_dev->real_device.regions[region_num];
121+    int m;
122+
123+    DEBUG("slow map type %i\n", type);
124+    m = cpu_register_io_memory(slow_bar_read, slow_bar_write, region);
125+    cpu_register_physical_memory(e_phys, e_size, m);
126+
127+    /* MSI-X MMIO page */
128+    if ((e_size > 0) &&
129+        real_region->base_addr <= r_dev->msix_table_addr &&
130+        real_region->base_addr + real_region->size >= r_dev->msix_table_addr) {
131+        int offset = r_dev->msix_table_addr - real_region->base_addr;
132+
133+        cpu_register_physical_memory(e_phys + offset,
134+                TARGET_PAGE_SIZE, r_dev->mmio_index);
135+    }
136+}
137+
138 static void assigned_dev_iomem_map(PCIDevice *pci_dev, int region_num,
139                                    pcibus_t e_phys, pcibus_t e_size, int type)
140 {
141@@ -456,15 +555,22 @@ static int assigned_dev_register_regions(PCIRegion *io_regions,
142
143         /* handle memory io regions */
144         if (cur_region->type & IORESOURCE_MEM) {
145+            int slow_map = 0;
146             int t = cur_region->type & IORESOURCE_PREFETCH
147                 ? PCI_BASE_ADDRESS_MEM_PREFETCH
148                 : PCI_BASE_ADDRESS_SPACE_MEMORY;
149+
150             if (cur_region->size & 0xFFF) {
151-                fprintf(stderr, "Unable to assign device: PCI region %d "
152-                        "at address 0x%llx has size 0x%x, "
153-                        " which is not a multiple of 4K\n",
154+                fprintf(stderr, "PCI region %d at address 0x%llx "
155+                        "has size 0x%x, which is not a multiple of 4K. "
156+                        "You might experience some performance hit due to that.\n",
157                         i, (unsigned long long)cur_region->base_addr,
158                         cur_region->size);
159+                slow_map = 1;
160+            }
161+
162+            if (slow_map && (i == PCI_ROM_SLOT)) {
163+                fprintf(stderr, "ROM not aligned - can't continue\n");
164                 return -1;
165             }
166
167@@ -480,7 +586,7 @@ static int assigned_dev_register_regions(PCIRegion *io_regions,
168             } else {
169                 pci_dev->v_addrs[i].u.r_virtbase =
170                     mmap(NULL,
171-                         (cur_region->size + 0xFFF) & 0xFFFFF000,
172+                         cur_region->size,
173                          PROT_WRITE | PROT_READ, MAP_SHARED,
174                          cur_region->resource_fd, (off_t) 0);
175             }
176@@ -507,7 +613,8 @@ static int assigned_dev_register_regions(PCIRegion *io_regions,
177
178             pci_register_bar((PCIDevice *) pci_dev, i,
179                              cur_region->size, t,
180-                             assigned_dev_iomem_map);
181+                             slow_map ? assigned_dev_iomem_map_slow
182+                                      : assigned_dev_iomem_map);
183             continue;
184         } else {
185             /* handle port io regions */
186