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authorPeter Grehan <grehan@FreeBSD.org>2013-10-09 23:53:21 +0000
committerPeter Grehan <grehan@FreeBSD.org>2013-10-09 23:53:21 +0000
commit2a8d400a2e9918ef77d30bdc099f5c06bae4302d (patch)
treef477d30d76163cb288da0ea06ed4847257f4024b
parentd5cc57e6abed1cff098cb8993c5c568a67c6ff60 (diff)
downloadsrc-2a8d400a2e9918ef77d30bdc099f5c06bae4302d.tar.gz
src-2a8d400a2e9918ef77d30bdc099f5c06bae4302d.zip
Allow a 4-byte write to PCI config space to overlap
the 2 read-only bytes at the start of a PCI capability. This is the sequence that OpenBSD uses when enabling MSI interrupts, and works fine on real h/w. In bhyve, convert the 4 byte write to a 2-byte write to the r/w area past the first 2 r/o bytes of a capability. Reviewed by: neel Approved by: re@ (blanket)
Notes
Notes: svn path=/head/; revision=256248
-rw-r--r--usr.sbin/bhyve/pci_emul.c15
1 files changed, 12 insertions, 3 deletions
diff --git a/usr.sbin/bhyve/pci_emul.c b/usr.sbin/bhyve/pci_emul.c
index a95f26101e3d..fe21cee835c2 100644
--- a/usr.sbin/bhyve/pci_emul.c
+++ b/usr.sbin/bhyve/pci_emul.c
@@ -941,10 +941,19 @@ pci_emul_capwrite(struct pci_devinst *pi, int offset, int bytes, uint32_t val)
assert(offset >= capoff);
/*
- * Capability ID and Next Capability Pointer are readonly
+ * Capability ID and Next Capability Pointer are readonly.
+ * However, some o/s's do 4-byte writes that include these.
+ * For this case, trim the write back to 2 bytes and adjust
+ * the data.
*/
- if (offset == capoff || offset == capoff + 1)
- return;
+ if (offset == capoff || offset == capoff + 1) {
+ if (offset == capoff && bytes == 4) {
+ bytes = 2;
+ offset += 2;
+ val >>= 16;
+ } else
+ return;
+ }
switch (capid) {
case PCIY_MSI: