| Message ID | 1483559838-8797-2-git-send-email-marcel@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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 <marcel@redhat.com> Kind of hacky and only theoretical - I don't think any guest writes there - but ok. However I think 1. we should init config to 0 too 2. this needs a compat flag > --- > 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
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 <marcel@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
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; }
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 <marcel@redhat.com> --- hw/pci/pcie.c | 3 +++ 1 file changed, 3 insertions(+)