Re: [libvirt] [PATCH 1/2] virpci: Introduce virPCIDeviceIsPCIExpress and friends

These functions will handle PCIe devices and their link capabilities to query some info about it. Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; --- src/libvirt_private.syms | 3 ++ src/util/virpci.c | 81 +++++++++++++++++++++++++++++++++++++++++++++++- src/util/virpci.h | 8 +++++ 3 files changed, 91 insertions(+), 1 deletion(-) diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index d73a9f5..f72a3ad 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -1690,6 +1690,8 @@ virPCIDeviceFree; virPCIDeviceGetDriverPathAndName; virPCIDeviceGetIOMMUGroupDev; virPCIDeviceGetIOMMUGroupList; +virPCIDeviceGetLinkCap; +virPCIDeviceGetLinkSta; virPCIDeviceGetManaged; virPCIDeviceGetName; virPCIDeviceGetRemoveSlot; @@ -1698,6 +1700,7 @@ virPCIDeviceGetStubDriver; virPCIDeviceGetUnbindFromStub; virPCIDeviceGetUsedBy; virPCIDeviceIsAssignable; +virPCIDeviceIsPCIExpress; virPCIDeviceListAdd; virPCIDeviceListAddCopy; virPCIDeviceListCount; diff --git a/src/util/virpci.c b/src/util/virpci.c index e0f2344..8ad28b8 100644 --- a/src/util/virpci.c +++ b/src/util/virpci.c @@ -130,7 +130,13 @@ struct _virPCIDeviceList { /* PCIe20 7.8.3 Device Capabilities Register (Offset 04h) */ #define PCI_EXP_DEVCAP 0x4 /* Device capabilities */ -#define PCI_EXP_DEVCAP_FLR (1<<28) /* Function Level Reset */ +#define PCI_EXP_LNKCAP 0xc /* Link Capabilities */ +#define PCI_EXP_LNKSTA 0x12 /* Link Status */ +#define PCI_EXP_DEVCAP_FLR (1<<28) /* Function Level Reset */ +#define PCI_EXP_LNKCAP_SPEED 0x0000f /* Maximum Link Speed */ +#define PCI_EXP_LNKCAP_WIDTH 0x003f0 /* Maximum Link Width */ +#define PCI_EXP_LNKSTA_SPEED 0x000f /* Negotiated Link Speed */ +#define PCI_EXP_LNKSTA_WIDTH 0x03f0 /* Negotiated Link Width */

/* Header type 1 BR12 3.2 PCI-to-PCI Bridge Configuration Space Header Format */ #define PCI_PRIMARY_BUS 0x18 /* BR12 3.2.5.2 Primary bus number */ @@ -2750,3 +2756,76 @@ virPCIGetVirtualFunctionInfo(const char *vf_sysfs_device_path ATTRIBUTE_UNUSED, return -1; } #endif /* __linux__ */ + +int +virPCIDeviceIsPCIExpress(virPCIDevicePtr dev) +{ + int fd; + int ret = -1; + + if ((fd = virPCIDeviceConfigOpen(dev, true)) < 0) + return ret; + + if (virPCIDeviceInit(dev, fd) < 0) + goto cleanup; + + ret = dev->pcie_cap_pos != 0; + + cleanup: + virPCIDeviceConfigClose(dev, fd); + return ret; +} + +int +virPCIDeviceGetLinkCap(virPCIDevicePtr dev, + int *port, + unsigned int *speed, + unsigned int *width) +{ + uint32_t t; + int fd; + int ret = -1; + + if ((fd = virPCIDeviceConfigOpen(dev, true) < 0)) + return ret; + + if (virPCIDeviceInit(dev, fd) < 0) + goto cleanup; + + t = virPCIDeviceRead32(dev, fd, dev->pcie_cap_pos + PCI_EXP_LNKCAP); + + *port = t >> 0x18;

+ *speed = t & PCI_EXP_LNKCAP_SPEED; + *width = (t & PCI_EXP_LNKCAP_WIDTH) >> 4;

+ ret = 0; + + cleanup: + virPCIDeviceConfigClose(dev, fd); + return ret; +} + +int +virPCIDeviceGetLinkSta(virPCIDevicePtr dev, + unsigned int *speed, + unsigned int *width) +{ + uint32_t t; + int fd; + int ret = -1; + + if ((fd = virPCIDeviceConfigOpen(dev, true) < 0)) + return ret; + + if (virPCIDeviceInit(dev, fd) < 0) + goto cleanup; + + t = virPCIDeviceRead32(dev, fd, dev->pcie_cap_pos + PCI_EXP_LNKSTA); + + *speed = t & PCI_EXP_LNKSTA_SPEED; + *width = (t & PCI_EXP_LNKSTA_WIDTH) >> 4; + ret = 0; + + cleanup: + virPCIDeviceConfigClose(dev, fd); + return ret; +}