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>
This commit is contained in:
Knut Omang 2019-02-21 19:13:22 +01:00 committed by Michael S. Tsirkin
parent a1fe0b8f27
commit db891a9ba3
3 changed files with 48 additions and 0 deletions

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@ -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);
}
}

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@ -79,6 +79,9 @@ struct PCIExpressDevice {
/* Offset of ATS capability in config space */
uint16_t ats_cap;
/* ACS */
uint16_t acs_cap;
};
#define COMPAT_PROP_PCP "power_controller_present"
@ -128,6 +131,9 @@ void pcie_add_capability(PCIDevice *dev,
uint16_t offset, uint16_t size);
void pcie_sync_bridge_lnk(PCIDevice *dev);
void pcie_acs_init(PCIDevice *dev, uint16_t offset);
void pcie_acs_reset(PCIDevice *dev);
void pcie_ari_init(PCIDevice *dev, uint16_t offset, uint16_t nextfn);
void pcie_dev_ser_num_init(PCIDevice *dev, uint16_t offset, uint64_t ser_num);
void pcie_ats_init(PCIDevice *dev, uint16_t offset);

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@ -175,4 +175,8 @@ typedef enum PCIExpLinkWidth {
PCI_ERR_COR_INTERNAL | \
PCI_ERR_COR_HL_OVERFLOW)
/* ACS */
#define PCI_ACS_VER 0x1
#define PCI_ACS_SIZEOF 8
#endif /* QEMU_PCIE_REGS_H */