diff options
author | Knut Omang <knut.omang@oracle.com> | 2019-02-21 19:13:22 +0100 |
---|---|---|
committer | Michael S. Tsirkin <mst@redhat.com> | 2019-03-12 22:31:21 -0400 |
commit | db891a9ba3b5aef52c2735f9b907d4d3678a86f8 (patch) | |
tree | 88a8ea37c10814e33c823325274657aa161cc169 /hw | |
parent | a1fe0b8f273c2272a7964655548179478b9d6a91 (diff) |
pcie: Add a simple PCIe ACS (Access Control Services) helper function
Implementing an ACS capability on downstream ports and multifunction
endpoints indicates isolation and IOMMU visibility to a finer
granularity. This creates smaller IOMMU groups in the guest and thus
more flexibility in assigning endpoints to guest userspace or an L2
guest.
Signed-off-by: Knut Omang <knut.omang@oracle.com>
Message-Id: <07489975121696f5573b0a92baaf3486ef51e35d.1550768238.git-series.knut.omang@oracle.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'hw')
-rw-r--r-- | hw/pci/pcie.c | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c index 640f678773..cf1ca30f93 100644 --- a/hw/pci/pcie.c +++ b/hw/pci/pcie.c @@ -914,3 +914,41 @@ void pcie_ats_init(PCIDevice *dev, uint16_t offset) pci_set_word(dev->wmask + dev->exp.ats_cap + PCI_ATS_CTRL, 0x800f); } + +/* ACS (Access Control Services) */ +void pcie_acs_init(PCIDevice *dev, uint16_t offset) +{ + bool is_downstream = pci_is_express_downstream_port(dev); + uint16_t cap_bits = 0; + + /* For endpoints, only multifunction devs may have an ACS capability: */ + assert(is_downstream || + (dev->cap_present & QEMU_PCI_CAP_MULTIFUNCTION) || + PCI_FUNC(dev->devfn)); + + pcie_add_capability(dev, PCI_EXT_CAP_ID_ACS, PCI_ACS_VER, offset, + PCI_ACS_SIZEOF); + dev->exp.acs_cap = offset; + + if (is_downstream) { + /* + * Downstream ports must implement SV, TB, RR, CR, UF, and DT (with + * caveats on the latter four that we ignore for simplicity). + * Endpoints may also implement a subset of ACS capabilities, + * but these are optional if the endpoint does not support + * peer-to-peer between functions and thus omitted here. + */ + cap_bits = PCI_ACS_SV | PCI_ACS_TB | PCI_ACS_RR | + PCI_ACS_CR | PCI_ACS_UF | PCI_ACS_DT; + } + + pci_set_word(dev->config + offset + PCI_ACS_CAP, cap_bits); + pci_set_word(dev->wmask + offset + PCI_ACS_CTRL, cap_bits); +} + +void pcie_acs_reset(PCIDevice *dev) +{ + if (dev->exp.acs_cap) { + pci_set_word(dev->config + dev->exp.acs_cap + PCI_ACS_CTRL, 0); + } +} |