Re: [PATCH 1/1] MdeModulePkg: Handle InitialVFs=0 case for SR-IOV


Ni, Ray
 

Reviewed-by: Ray Ni <ray.ni@...>

-----Original Message-----
From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Foster Nong
Sent: Thursday, September 29, 2022 5:20 PM
To: devel@edk2.groups.io
Cc: Nong, Foster <foster.nong@...>
Subject: [edk2-devel] [PATCH 1/1] MdeModulePkg: Handle InitialVFs=0 case for SR-IOV

Per the section 3.3.5 SR-IOV spec v1.1, InitialVFs (0ch).
InitialVFs indicates to SR-PCIM the number of VFs that are initially associated with the PF.
The minimum value of InitialVFs is 0.

Below code is used to calculate SR-IOV reserved bus number,
if InitialVFs =0, it maybe calculate the wrong bus number in this case.
LastVF = PFRid + FirstVFOffset + (PciIoDevice->InitialVFs - 1) * VFStride

we can fix it with below code:
if (PciIoDevice->InitialVFs == 0) {
PciIoDevice->ReservedBusNum = 0;
} else {
PFRid = EFI_PCI_RID (Bus, Device, Func);
LastVF = PFRid + FirstVFOffset + (PciIoDevice->InitialVFs - 1) * VFStride;
//
// Calculate ReservedBusNum for this PF
//
PciIoDevice->ReservedBusNum = (UINT16)(EFI_PCI_BUS_OF_RID (LastVF) - Bus + 1);
//
// Calculate ReservedBusNum for this PF
//
PciIoDevice->ReservedBusNum = (UINT16)(EFI_PCI_BUS_OF_RID (LastVF) - Bus + 1);
}

https://bugzilla.tianocore.org/show_bug.cgi?id=4069

Signed-off-by: Foster Nong <foster.nong@...>
---
.../Bus/Pci/PciBusDxe/PciEnumeratorSupport.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c
b/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c
index 509f828b621d..eb250f6f7b62 100644
--- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c
+++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c
@@ -2416,13 +2416,17 @@ CreatePciIoDevice (
//
// Calculate LastVF
//
- PFRid = EFI_PCI_RID (Bus, Device, Func);
- LastVF = PFRid + FirstVFOffset + (PciIoDevice->InitialVFs - 1) * VFStride;
+ if (PciIoDevice->InitialVFs == 0) {
+ PciIoDevice->ReservedBusNum = 0;
+ } else {
+ PFRid = EFI_PCI_RID (Bus, Device, Func);
+ LastVF = PFRid + FirstVFOffset + (PciIoDevice->InitialVFs - 1) * VFStride;

- //
- // Calculate ReservedBusNum for this PF
- //
- PciIoDevice->ReservedBusNum = (UINT16)(EFI_PCI_BUS_OF_RID (LastVF) - Bus + 1);
+ //
+ // Calculate ReservedBusNum for this PF
+ //
+ PciIoDevice->ReservedBusNum = (UINT16)(EFI_PCI_BUS_OF_RID (LastVF) - Bus + 1);
+ }

DEBUG ((
DEBUG_INFO,
--
2.37.1.windows.1




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