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.

upstream-commit-id: 69976894c1d91c4b0c985fa05936cb6b8d01382b

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 f91b7cdd745c0d15583d0cfc523c2b73f422f554..efb158fa791c40e0df78e39780a3f48354bbea2f 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 25f53d970fe788a80e1ccee5818fda47abb79b15..728797ebfeec5e209895e7791a9511796249c406 100644 (file)
--- a/hw/xen/xen_pt_config_init.c
+++ b/hw/xen/xen_pt_config_init.c
@@ -731,8 +731,8 @@ 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,