From f0a3eaff71b8bd5d5acfda1f0cf3eedf49755622 Mon Sep 17 00:00:00 2001 From: Victor Kamensky Date: Wed, 2 Jul 2014 17:19:30 +0100 Subject: [PATCH] ARM64: KVM: fix big endian issue in access_vm_reg for 32bit guest Fix issue with 32bit guests running on top of BE KVM host. Indexes of high and low words of 64bit cp15 register are swapped in case of big endian code, since 64bit cp15 state is restored or saved with double word write or read instruction. Define helper macro to access low words of 64bit cp15 register. Signed-off-by: Victor Kamensky Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/kvm_host.h | 6 ++++++ arch/arm64/kvm/sys_regs.c | 10 ++++------ 2 files changed, 10 insertions(+), 6 deletions(-) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 4ae9213aa997..503c70661636 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -140,6 +140,12 @@ struct kvm_vcpu_arch { #define vcpu_sys_reg(v,r) ((v)->arch.ctxt.sys_regs[(r)]) #define vcpu_cp15(v,r) ((v)->arch.ctxt.cp15[(r)]) +#ifdef CONFIG_CPU_BIG_ENDIAN +#define vcpu_cp15_64_low(v,r) ((v)->arch.ctxt.cp15[((r) + 1)]) +#else +#define vcpu_cp15_64_low(v,r) ((v)->arch.ctxt.cp15[((r) + 0)]) +#endif + struct kvm_vm_stat { u32 remote_tlb_flush; }; diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index f0ceceffa95a..56288f31c12d 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -134,13 +134,11 @@ static bool access_vm_reg(struct kvm_vcpu *vcpu, BUG_ON(!p->is_write); val = *vcpu_reg(vcpu, p->Rt); - if (!p->is_aarch32) { + if (!p->is_aarch32 || !p->is_32bit) vcpu_sys_reg(vcpu, r->reg) = val; - } else { - vcpu_cp15(vcpu, r->reg) = val & 0xffffffffUL; - if (!p->is_32bit) - vcpu_cp15(vcpu, r->reg + 1) = val >> 32; - } + else + vcpu_cp15_64_low(vcpu, r->reg) = val & 0xffffffffUL; + return true; }