From 1c9e3d51d5410acbc4fad70d59370ec2f13c6748 Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Thu, 12 Nov 2015 16:43:48 +1100 Subject: KVM: PPC: Book3S HV: Handle unexpected traps in guest entry/exit code better As we saw with the TM Bad Thing type of program interrupt occurring on the hrfid that enters the guest, it is not completely impossible to have a trap occurring in the guest entry/exit code, despite the fact that the code has been written to avoid taking any traps. This adds a check in the kvmppc_handle_exit_hv() function to detect the case when a trap has occurred in the hypervisor-mode code, and instead of treating it just like a trap in guest code, we now print a message and return to userspace with a KVM_EXIT_INTERNAL_ERROR exit reason. Of the various interrupts that get handled in the assembly code in the guest exit path and that can return directly to the guest, the only one that can occur when MSR.HV=1 and MSR.EE=0 is machine check (other than system call, which we can avoid just by not doing a sc instruction). Therefore this adds code to the machine check path to ensure that if the MCE occurred in hypervisor mode, we exit to the host rather than trying to continue the guest. Signed-off-by: Paul Mackerras --- arch/powerpc/kvm/book3s_hv.c | 18 ++++++++++++++++++ arch/powerpc/kvm/book3s_hv_rmhandlers.S | 2 ++ 2 files changed, 20 insertions(+) (limited to 'arch/powerpc/kvm') diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index a29da44cdc6c..89eafd16f408 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -827,6 +827,24 @@ static int kvmppc_handle_exit_hv(struct kvm_run *run, struct kvm_vcpu *vcpu, vcpu->stat.sum_exits++; + /* + * This can happen if an interrupt occurs in the last stages + * of guest entry or the first stages of guest exit (i.e. after + * setting paca->kvm_hstate.in_guest to KVM_GUEST_MODE_GUEST_HV + * and before setting it to KVM_GUEST_MODE_HOST_HV). + * That can happen due to a bug, or due to a machine check + * occurring at just the wrong time. + */ + if (vcpu->arch.shregs.msr & MSR_HV) { + printk(KERN_EMERG "KVM trap in HV mode!\n"); + printk(KERN_EMERG "trap=0x%x | pc=0x%lx | msr=0x%llx\n", + vcpu->arch.trap, kvmppc_get_pc(vcpu), + vcpu->arch.shregs.msr); + kvmppc_dump_regs(vcpu); + run->exit_reason = KVM_EXIT_INTERNAL_ERROR; + run->hw.hardware_exit_reason = vcpu->arch.trap; + return RESUME_HOST; + } run->exit_reason = KVM_EXIT_UNKNOWN; run->ready_for_interrupt_injection = 1; switch (vcpu->arch.trap) { diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index 3c6badcd53ef..b3ce8ff18195 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -2404,6 +2404,8 @@ machine_check_realmode: * guest as machine check causing guest to crash. */ ld r11, VCPU_MSR(r9) + rldicl. r0, r11, 64-MSR_HV_LG, 63 /* check if it happened in HV mode */ + bne mc_cont /* if so, exit to host */ andi. r10, r11, MSR_RI /* check for unrecoverable exception */ beq 1f /* Deliver a machine check to guest */ ld r10, VCPU_PC(r9) -- cgit v1.2.1 From 760a7364f27d974d100118d88190e574626e18a6 Mon Sep 17 00:00:00 2001 From: Thomas Huth Date: Fri, 20 Nov 2015 09:11:45 +0100 Subject: KVM: PPC: Fix emulation of H_SET_DABR/X on POWER8 In the old DABR register, the BT (Breakpoint Translation) bit is bit number 61. In the new DAWRX register, the WT (Watchpoint Translation) bit is bit number 59. So to move the DABR-BT bit into the position of the DAWRX-WT bit, it has to be shifted by two, not only by one. This fixes hardware watchpoints in gdb of older guests that only use the H_SET_DABR/X interface instead of the new H_SET_MODE interface. Cc: stable@vger.kernel.org # v3.14+ Signed-off-by: Thomas Huth Reviewed-by: Laurent Vivier Reviewed-by: David Gibson Signed-off-by: Paul Mackerras --- arch/powerpc/kvm/book3s_hv_rmhandlers.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/powerpc/kvm') diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index b3ce8ff18195..6ee26de9a1de 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -2153,7 +2153,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S) /* Emulate H_SET_DABR/X on P8 for the sake of compat mode guests */ 2: rlwimi r5, r4, 5, DAWRX_DR | DAWRX_DW - rlwimi r5, r4, 1, DAWRX_WT + rlwimi r5, r4, 2, DAWRX_WT clrrdi r4, r4, 3 std r4, VCPU_DAWR(r3) std r5, VCPU_DAWRX(r3) -- cgit v1.2.1 From edfaff269f94e81b9fbaa130e0ad7776fbb523e2 Mon Sep 17 00:00:00 2001 From: "Geyslan G. Bem" Date: Tue, 1 Dec 2015 20:42:10 -0300 Subject: KVM: PPC: Book3S PR: Remove unused variable 'vcpu_book3s' The vcpu_book3s variable is assigned but never used. So remove it. Found using cppcheck. Signed-off-by: Geyslan G. Bem Signed-off-by: Paul Mackerras --- arch/powerpc/kvm/book3s_64_mmu.c | 3 --- 1 file changed, 3 deletions(-) (limited to 'arch/powerpc/kvm') diff --git a/arch/powerpc/kvm/book3s_64_mmu.c b/arch/powerpc/kvm/book3s_64_mmu.c index 774a253ca4e1..9bf7031a67ff 100644 --- a/arch/powerpc/kvm/book3s_64_mmu.c +++ b/arch/powerpc/kvm/book3s_64_mmu.c @@ -377,15 +377,12 @@ no_seg_found: static void kvmppc_mmu_book3s_64_slbmte(struct kvm_vcpu *vcpu, u64 rs, u64 rb) { - struct kvmppc_vcpu_book3s *vcpu_book3s; u64 esid, esid_1t; int slb_nr; struct kvmppc_slb *slbe; dprintk("KVM MMU: slbmte(0x%llx, 0x%llx)\n", rs, rb); - vcpu_book3s = to_book3s(vcpu); - esid = GET_ESID(rb); esid_1t = GET_ESID_1T(rb); slb_nr = rb & 0xfff; -- cgit v1.2.1 From b4d7f161feb3015d6306e1d35b565c888ff70c9d Mon Sep 17 00:00:00 2001 From: Greg Kurz Date: Wed, 13 Jan 2016 18:28:17 +0100 Subject: KVM: PPC: Fix ONE_REG AltiVec support The get and set operations got exchanged by mistake when moving the code from book3s.c to powerpc.c. Fixes: 3840edc8033ad5b86deee309c1c321ca54257452 Cc: stable@vger.kernel.org # 3.18+ Signed-off-by: Greg Kurz Signed-off-by: Paul Mackerras --- arch/powerpc/kvm/powerpc.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) (limited to 'arch/powerpc/kvm') diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index 6fd2405c7f4a..a3b182dcb823 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -919,21 +919,17 @@ int kvm_vcpu_ioctl_get_one_reg(struct kvm_vcpu *vcpu, struct kvm_one_reg *reg) r = -ENXIO; break; } - vcpu->arch.vr.vr[reg->id - KVM_REG_PPC_VR0] = val.vval; + val.vval = vcpu->arch.vr.vr[reg->id - KVM_REG_PPC_VR0]; break; case KVM_REG_PPC_VSCR: if (!cpu_has_feature(CPU_FTR_ALTIVEC)) { r = -ENXIO; break; } - vcpu->arch.vr.vscr.u[3] = set_reg_val(reg->id, val); + val = get_reg_val(reg->id, vcpu->arch.vr.vscr.u[3]); break; case KVM_REG_PPC_VRSAVE: - if (!cpu_has_feature(CPU_FTR_ALTIVEC)) { - r = -ENXIO; - break; - } - vcpu->arch.vrsave = set_reg_val(reg->id, val); + val = get_reg_val(reg->id, vcpu->arch.vrsave); break; #endif /* CONFIG_ALTIVEC */ default: @@ -974,17 +970,21 @@ int kvm_vcpu_ioctl_set_one_reg(struct kvm_vcpu *vcpu, struct kvm_one_reg *reg) r = -ENXIO; break; } - val.vval = vcpu->arch.vr.vr[reg->id - KVM_REG_PPC_VR0]; + vcpu->arch.vr.vr[reg->id - KVM_REG_PPC_VR0] = val.vval; break; case KVM_REG_PPC_VSCR: if (!cpu_has_feature(CPU_FTR_ALTIVEC)) { r = -ENXIO; break; } - val = get_reg_val(reg->id, vcpu->arch.vr.vscr.u[3]); + vcpu->arch.vr.vscr.u[3] = set_reg_val(reg->id, val); break; case KVM_REG_PPC_VRSAVE: - val = get_reg_val(reg->id, vcpu->arch.vrsave); + if (!cpu_has_feature(CPU_FTR_ALTIVEC)) { + r = -ENXIO; + break; + } + vcpu->arch.vrsave = set_reg_val(reg->id, val); break; #endif /* CONFIG_ALTIVEC */ default: -- cgit v1.2.1