Commit 19c585eb authored by Simon Guo's avatar Simon Guo Committed by Paul Mackerras
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KVM: PPC: Book3S PR: Restore NV regs after emulating mfspr from TM SPRs 



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: default avatarSimon Guo <wei.guo.simon@gmail.com>
Reviewed-by: default avatarPaul Mackerras <paulus@ozlabs.org>
Signed-off-by: default avatarPaul Mackerras <paulus@ozlabs.org>
parent 5706340a

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: