From 06c757b88417d8abd71de7c37426812534226b04 Mon Sep 17 00:00:00 2001 From: James Hogan Date: Thu, 29 May 2014 10:16:23 +0100 Subject: [PATCH] MIPS: KVM: Allocate at least 16KB for exception handlers commit 7006e2dfda9adfa40251093604db76d7e44263b3 upstream. Each MIPS KVM guest has its own copy of the KVM exception vector. This contains the TLB refill exception handler at offset 0x000, the general exception handler at offset 0x180, and interrupt exception handlers at offset 0x200 in case Cause_IV=1. A common handler is copied to offset 0x2000 and offset 0x3000 is used for temporarily storing k1 during entry from guest. However the amount of memory allocated for this purpose is calculated as 0x200 rounded up to the next page boundary, which is insufficient if 4KB pages are in use. This can lead to the common handler at offset 0x2000 being overwritten and infinitely recursive exceptions on the next exit from the guest. Increase the minimum size from 0x200 to 0x4000 to cover the full use of the page. Signed-off-by: James Hogan Cc: Paolo Bonzini Cc: Gleb Natapov Cc: kvm@vger.kernel.org Cc: Ralf Baechle Cc: linux-mips@linux-mips.org Cc: Sanjay Lal Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/mips/kvm/kvm_mips.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/mips/kvm/kvm_mips.c b/arch/mips/kvm/kvm_mips.c index dd203e59e6fd..426345ac6f6e 100644 --- a/arch/mips/kvm/kvm_mips.c +++ b/arch/mips/kvm/kvm_mips.c @@ -299,7 +299,7 @@ struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id) if (cpu_has_veic || cpu_has_vint) { size = 0x200 + VECTORSPACING * 64; } else { - size = 0x200; + size = 0x4000; } /* Save Linux EBASE */ -- 2.20.1