Hi Adrian, I think the mailing list discussions here should be sufficient. However, it would be great if you can test that the earlier patch works and reply with a tested-by. Regards, Sami Mujawar From: Adrián Herrera Arcila Date: Tuesday, 27 April 2021 at 10:48 To: Sami Mujawar Cc: devel@edk2.groups.io , Joey Gouly , Ard Biesheuvel , leif@nuviainc.com , nd Subject: Re: [edk2-devel] [PATCH] ArmPkg/ArmGicLib: fix maximum interrupts supported Hi Sami, That patch provides the same solution. I'll be sure to check the mailing list before sending the next time. Any benefit on marking this as duplicate? If so, how could I do it? Thank you, Adrián. On Mon, 26 Apr 2021 at 08:56, Sami Mujawar > wrote: Hi Adrian, I believe there is already a similar patch on the mailing list at https://edk2.groups.io/g/devel/message/72596. This patch is pending review and tested-by. Can you check if this patch covers the problems you describe, please? Regards, Sami Mujawar From: devel@edk2.groups.io > on behalf of Adrián Herrera via groups.io > Date: Saturday, 24 April 2021 at 03:57 To: devel@edk2.groups.io > Cc: Adrián Herrera > Subject: [edk2-devel] [PATCH] ArmPkg/ArmGicLib: fix maximum interrupts supported The maximum number of interrupts supported is determined as 32 * (GICD_TYPER.ITLinesNumber + 1). When GICD_TYPER.ITLinesNumber = 0b11111, the maximum number of interrupts supported is 1024. However, both GICv2 and GICv3 reserve INTIDs 1020-1023 for special purposes. This results in runtime crashes because: (1) ArmGicLib functions do not guard against special interrupts. (2) ArmGicGetMaxNumInterrupts number includes special interrupts. (2) ArmGicV*Dxe relies on ArmGicGetMaxNumInterrupts, and thus programs special interrupts through ArmGicLib. ArmGicGetMaxNumInterrupts now does not include special interrupts, that is, it reports 1020 instead of 1024 when GICD_TYPER.ITLinesNumber = 0b11111. This avoids the overhead of guarding ArmGicLib functions while not requiring to modify the drivers code. Signed-off-by: Adrián Herrera > --- ArmPkg/Drivers/ArmGic/ArmGicLib.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/ArmPkg/Drivers/ArmGic/ArmGicLib.c b/ArmPkg/Drivers/ArmGic/ArmGicLib.c index 6b01c88206..dff1401e9c 100644 --- a/ArmPkg/Drivers/ArmGic/ArmGicLib.c +++ b/ArmPkg/Drivers/ArmGic/ArmGicLib.c @@ -120,7 +120,10 @@ ArmGicGetMaxNumInterrupts ( IN INTN GicDistributorBase ) { - return 32 * ((MmioRead32 (GicDistributorBase + ARM_GIC_ICDICTR) & 0x1F) + 1); + UINT32 ITLinesNumber; + + ITLinesNumber = MmioRead32 (GicDistributorBase + ARM_GIC_ICDICTR) & 0x1F; + return MIN (32 * (ITLinesNumber+ 1), 1020); } VOID -- 2.30.0