[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen stable-4.16] arm/vgic-v3: fix virq offset in the rank when storing irouter
commit 3050769a171a881b6225c98c750e1c5f92311081 Author: Hongda Deng <Hongda.Deng@xxxxxxx> AuthorDate: Fri Jul 29 16:36:02 2022 +0800 Commit: Stefano Stabellini <stefano.stabellini@xxxxxxx> CommitDate: Wed Aug 3 14:57:58 2022 -0700 arm/vgic-v3: fix virq offset in the rank when storing irouter When vGIC performs irouter registers emulation, to get the target vCPU via virq conveniently, Xen doesn't store the irouter value directly, instead it will use the value (affinities) in irouter to calculate the target vCPU, and then save the target vCPU in irq rank->vcpu[offset]. When vGIC tries to get the target vCPU, it first calculates the target vCPU index via int target = read_atomic(&rank->vcpu[virq & INTERRUPT_RANK_MASK]); and then it gets the target vCPU via v->domain->vcpu[target]; When vGIC tries to store irouter for one virq, the target vCPU index in the rank is computed as offset &= virq & INTERRUPT_RANK_MASK; finally it gets the target vCPU via d->vcpu[read_atomic(&rank->vcpu[offset])]; There is a difference between them while getting the target vCPU index in the rank. Actually (virq & INTERRUPT_RANK_MASK) would already get the target vCPU index in the rank, it's wrong to add '&' before '=' when calculate the offset. For example, the target vCPU index in the rank should be 6 for virq 38, but vGIC will get offset=0 when vGIC stores the irouter for this virq, and finally vGIC will access the wrong target vCPU index in the rank when updating the irouter. Fixes: 5d495f4349b5 ("xen/arm: vgic: Optimize the way to store the target vCPU in the rank") Signed-off-by: Hongda Deng <Hongda.Deng@xxxxxxx> Reviewed-by: Julien Grall <jgrall@xxxxxxxxxx> (cherry picked from commit 800f21499e0ec112771ce1e94490ca5811578bc2) --- xen/arch/arm/vgic-v3.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/xen/arch/arm/vgic-v3.c b/xen/arch/arm/vgic-v3.c index 65bb7991a6..191cfd0959 100644 --- a/xen/arch/arm/vgic-v3.c +++ b/xen/arch/arm/vgic-v3.c @@ -135,7 +135,7 @@ static void vgic_store_irouter(struct domain *d, struct vgic_irq_rank *rank, ASSERT(virq >= 32); /* Get the index in the rank */ - offset &= virq & INTERRUPT_RANK_MASK; + offset = virq & INTERRUPT_RANK_MASK; new_vcpu = vgic_v3_irouter_to_vcpu(d, irouter); old_vcpu = d->vcpu[read_atomic(&rank->vcpu[offset])]; -- generated by git-patchbot for /home/xen/git/xen.git#stable-4.16
|
![]() |
Lists.xenproject.org is hosted with RackSpace, monitoring our |