On 01/10/2017 05:13 AM, Michael S. Tsirkin wrote:
On Wed, Jan 04, 2017 at 09:57:15PM +0200, Marcel Apfelbaum wrote:
Absence of any Extended Capabilities is required to be
indicated by an Extended Capability header with a Capability ID of
0000h, a Capability Version of 0h, and a Next Capability Offset of 000h.
Instead of inserting a 'NULL' capability is simpler to mark the start
of the Extended Configuration Space as read-only to achieve the same
behaviour.
Signed-off-by: Marcel Apfelbaum <mar...@redhat.com>
Kind of hacky and only theoretical - I don't think any guest writes
there - but ok.
I agree is theoretical, but Windows PCI Hardware Compliance WHQL tests find it.
However I think
1. we should init config to 0 too
What do you mean? Have a 'Null' capability for regular PCI capabilities list?
I'll have a look on the spec to see if is required.
2. this needs a compat flag
Sure, I'll add one.
Thanks,
Marcel
---
hw/pci/pcie.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
index 99cfb45..62c1def 100644
--- a/hw/pci/pcie.c
+++ b/hw/pci/pcie.c
@@ -109,6 +109,9 @@ int pcie_cap_init(PCIDevice *dev, uint8_t offset, uint8_t
type, uint8_t port)
PCI_EXP_DEVCAP2_EFF | PCI_EXP_DEVCAP2_EETLPP);
pci_set_word(dev->wmask + pos + PCI_EXP_DEVCTL2, PCI_EXP_DEVCTL2_EETLPPB);
+
+ /* read-only to behave like a 'NULL' Extended Capability Header */
+ pci_set_long(dev->wmask + PCI_CONFIG_SPACE_SIZE, 0);
return pos;
}
--
2.5.5
