xen/pass-through: ROM BAR handling adjustments

Expecting the ROM BAR to be written with an all ones value when sizing
the region is wrong - the low bit has another meaning (enable/disable)
and bits 1..10 are reserved. The PCI spec also mandates writing all
ones to just the address portion of the register.

Use suitable constants also for initializing the ROM BAR register field
description.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>

diff --git a/hw/xen/xen_pt.c b/hw/xen/xen_pt.c
index 8d47a4502c9c4588567bcfd47c724970fdb74067..7b8a31e4b7bd193bc4dd660118d42e8d28143fac 100644 (file)
--- a/hw/xen/xen_pt.c
+++ b/hw/xen/xen_pt.c
@@ -249,10 +249,18 @@ static void xen_pt_pci_write_config(PCIDevice *d, uint32_t addr,
 
     /* check unused BAR register */
     index = xen_pt_bar_offset_to_index(addr);
-    if ((index >= 0) && (val > 0 && val < XEN_PT_BAR_ALLF) &&
-        (s->bases[index].bar_flag == XEN_PT_BAR_FLAG_UNUSED)) {
-        XEN_PT_WARN(d, "Guest attempt to set address to unused Base Address "
-                    "Register. (addr: 0x%02x, len: %d)\n", addr, len);
+    if ((index >= 0) && (val != 0)) {
+        uint32_t chk = val;
+
+        if (index == PCI_ROM_SLOT)
+            chk |= (uint32_t)~PCI_ROM_ADDRESS_MASK;
+
+        if ((chk != XEN_PT_BAR_ALLF) &&
+            (s->bases[index].bar_flag == XEN_PT_BAR_FLAG_UNUSED)) {
+            XEN_PT_WARN(d, "Guest attempt to set address to unused "
+                        "Base Address Register. (addr: 0x%02x, len: %d)\n",
+                        addr, len);
+        }
     }
 
     /* find register group entry */

diff --git a/hw/xen/xen_pt_config_init.c b/hw/xen/xen_pt_config_init.c
index f3cf069b60e1173712fed2c31339c73f2de8678d..f3730928d7937fb68b048dbbc9a2cfcfb0992f9c 100644 (file)
--- a/hw/xen/xen_pt_config_init.c
+++ b/hw/xen/xen_pt_config_init.c
@@ -729,8 +729,8 @@ static XenPTRegInfo xen_pt_emu_reg_header0[] = {
         .offset     = PCI_ROM_ADDRESS,
         .size       = 4,
         .init_val   = 0x00000000,
-        .ro_mask    = 0x000007FE,
-        .emu_mask   = 0xFFFFF800,
+        .ro_mask    = ~PCI_ROM_ADDRESS_MASK & ~PCI_ROM_ADDRESS_ENABLE,
+        .emu_mask   = (uint32_t)PCI_ROM_ADDRESS_MASK,
         .init       = xen_pt_bar_reg_init,
         .u.dw.read  = xen_pt_long_reg_read,
         .u.dw.write = xen_pt_exp_rom_bar_reg_write,