KVM: PPC: Book3S PR: Restore NV regs after emulating mfspr from TM SPRs (19c585eb) · Commits · 戴 / test

Currently kvmppc_handle_fac() will not update NV GPRs and thus it can return with GUEST_RESUME. However PR KVM guest always disables MSR_TM bit in privileged state. If PR privileged-state guest is trying to read TM SPRs, it will trigger TM facility unavailable exception and fall into kvmppc_handle_fac(). Then the emulation will be done by kvmppc_core_emulate_mfspr_pr(). The mfspr instruction can include a RT with NV reg. So it is necessary to restore NV GPRs at this case, to reflect the update to NV RT. This patch make kvmppc_handle_fac() return GUEST_RESUME_NV for TM facility unavailable exceptions in guest privileged state. Signed-off-by:

Simon Guo <wei.guo.simon@gmail.com> Reviewed-by:

Paul Mackerras <paulus@ozlabs.org> Signed-off-by:

Paul Mackerras <paulus@ozlabs.org>

arch/powerpc/kvm/book3s_pr.c

+13 −2

Original line number	Diff line number	Diff line
		@@ -989,6 +989,18 @@ static int kvmppc_handle_fac(struct kvm_vcpu *vcpu, ulong fac)
		break;
		}

		#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
		/* Since we disabled MSR_TM at privilege state, the mfspr instruction
		* for TM spr can trigger TM fac unavailable. In this case, the
		* emulation is handled by kvmppc_emulate_fac(), which invokes
		* kvmppc_emulate_mfspr() finally. But note the mfspr can include
		* RT for NV registers. So it need to restore those NV reg to reflect
		* the update.
		*/
		if ((fac == FSCR_TM_LG) && !(kvmppc_get_msr(vcpu) & MSR_PR))
		return RESUME_GUEST_NV;
		#endif

		return RESUME_GUEST;
		}

		@@ -1350,8 +1362,7 @@ int kvmppc_handle_exit_pr(struct kvm_run run, struct kvm_vcpu vcpu,
		}
		#ifdef CONFIG_PPC_BOOK3S_64
		case BOOK3S_INTERRUPT_FAC_UNAVAIL:
		kvmppc_handle_fac(vcpu, vcpu->arch.shadow_fscr >> 56);
		r = RESUME_GUEST;
		r = kvmppc_handle_fac(vcpu, vcpu->arch.shadow_fscr >> 56);
		break;
		#endif
		case BOOK3S_INTERRUPT_MACHINE_CHECK:

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