From: Aurelien Jarno <aurelien@aurel32.net>
To: qemu-devel@nongnu.org
Subject: [Qemu-devel] [6091] PCI: Mask writes to RO bits in the status reg of PCI config space
Date: Thu, 18 Dec 2008 22:43:33 +0000 [thread overview]
Message-ID: <E1LDRaf-0002Qc-Jn@cvs.savannah.gnu.org> (raw)
Revision: 6091
http://svn.sv.gnu.org/viewvc/?view=rev&root=qemu&revision=6091
Author: aurel32
Date: 2008-12-18 22:43:33 +0000 (Thu, 18 Dec 2008)
Log Message:
-----------
PCI: Mask writes to RO bits in the status reg of PCI config space
The Status register in the PCI config space has some read-only bits.
Any writes to those bits should be masked out.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Modified Paths:
--------------
trunk/hw/pci.c
trunk/hw/pci.h
Modified: trunk/hw/pci.c
===================================================================
--- trunk/hw/pci.c 2008-12-18 22:43:25 UTC (rev 6090)
+++ trunk/hw/pci.c 2008-12-18 22:43:33 UTC (rev 6091)
@@ -381,6 +381,7 @@
case 0x0b:
case 0x0e:
case 0x10 ... 0x27: /* base */
+ case 0x2c ... 0x2f: /* read-only subsystem ID & vendor ID */
case 0x30 ... 0x33: /* rom */
case 0x3d:
can_write = 0;
@@ -402,6 +403,7 @@
case 0x0a:
case 0x0b:
case 0x0e:
+ case 0x2c ... 0x2f: /* read-only subsystem ID & vendor ID */
case 0x38 ... 0x3b: /* rom */
case 0x3d:
can_write = 0;
@@ -413,6 +415,15 @@
break;
}
if (can_write) {
+ /* Mask out writes to reserved bits in registers */
+ switch (addr) {
+ case 0x06:
+ val &= ~PCI_STATUS_RESERVED_MASK_LO;
+ break;
+ case 0x07:
+ val &= ~PCI_STATUS_RESERVED_MASK_HI;
+ break;
+ }
d->config[addr] = val;
}
if (++addr > 0xff)
Modified: trunk/hw/pci.h
===================================================================
--- trunk/hw/pci.h 2008-12-18 22:43:25 UTC (rev 6090)
+++ trunk/hw/pci.h 2008-12-18 22:43:33 UTC (rev 6091)
@@ -54,6 +54,21 @@
#define PCI_MIN_GNT 0x3e /* 8 bits */
#define PCI_MAX_LAT 0x3f /* 8 bits */
+/* Bits in the PCI Status Register (PCI 2.3 spec) */
+#define PCI_STATUS_RESERVED1 0x007
+#define PCI_STATUS_INT_STATUS 0x008
+#define PCI_STATUS_CAPABILITIES 0x010
+#define PCI_STATUS_66MHZ 0x020
+#define PCI_STATUS_RESERVED2 0x040
+#define PCI_STATUS_FAST_BACK 0x080
+#define PCI_STATUS_DEVSEL 0x600
+
+#define PCI_STATUS_RESERVED_MASK_LO (PCI_STATUS_RESERVED1 | \
+ PCI_STATUS_INT_STATUS | PCI_STATUS_CAPABILITIES | \
+ PCI_STATUS_66MHZ | PCI_STATUS_RESERVED2 | PCI_STATUS_FAST_BACK)
+
+#define PCI_STATUS_RESERVED_MASK_HI (PCI_STATUS_DEVSEL >> 8)
+
struct PCIDevice {
/* PCI config space */
uint8_t config[256];
reply other threads:[~2008-12-18 22:43 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=E1LDRaf-0002Qc-Jn@cvs.savannah.gnu.org \
--to=aurelien@aurel32.net \
--cc=qemu-devel@nongnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).