From: Matthew Rosato Date: Fri, 24 Apr 2026 19:39:00 +0000 (-0400) Subject: KVM: s390: pci: Fix aisb calculation X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=0cfe660559e857d7c00ab86c73e4510ce069086f;p=thirdparty%2Flinux.git KVM: s390: pci: Fix aisb calculation The current implementation of aisb calculation will erroneously index via an unsigned long * as well as multiply by 8B for every 64-bits in the offset; only one or the other is required. This throws off aisb calculations once the number of devices exceeds 64, and can result in out-of-bounds access as well as failure to indicate summary bits associated with those devices in guests. Fix this by converting to a physical address before applying the offset, as is already done in arch/s390/pci/pci_irq.c. Fixes: 3c5a1b6f0a18 ("KVM: s390: pci: provide routines for enabling/disabling interrupt forwarding") Signed-off-by: Matthew Rosato Reviewed-by: Niklas Schnelle Signed-off-by: Christian Borntraeger --- diff --git a/arch/s390/kvm/pci.c b/arch/s390/kvm/pci.c index eed45af1a92d..5b075c38998e 100644 --- a/arch/s390/kvm/pci.c +++ b/arch/s390/kvm/pci.c @@ -166,7 +166,7 @@ static int kvm_zpci_set_airq(struct zpci_dev *zdev) fib.fmt0.noi = airq_iv_end(zdev->aibv); fib.fmt0.aibv = virt_to_phys(zdev->aibv->vector); fib.fmt0.aibvo = 0; - fib.fmt0.aisb = virt_to_phys(aift->sbv->vector + (zdev->aisb / 64) * 8); + fib.fmt0.aisb = virt_to_phys(aift->sbv->vector) + (zdev->aisb / 64) * 8; fib.fmt0.aisbo = zdev->aisb & 63; fib.gd = zdev->gisa; @@ -308,7 +308,7 @@ static int kvm_s390_pci_aif_enable(struct zpci_dev *zdev, struct zpci_fib *fib, /* Update guest FIB for re-issue */ fib->fmt0.aisbo = zdev->aisb & 63; - fib->fmt0.aisb = virt_to_phys(aift->sbv->vector + (zdev->aisb / 64) * 8); + fib->fmt0.aisb = virt_to_phys(aift->sbv->vector) + (zdev->aisb / 64) * 8; fib->fmt0.isc = gisc; /* Save some guest fib values in the host for later use */