Re: [PATCH v2] KVM: PPC: Fix contents of SRR1 when injecting a program exception in kvm-pr

[Thomas Huth <thuth@redhat.com>]

On 19.05.2016 11:33, Thomas Huth wrote:
> vcpu->arch.shadow_srr1 only contains usable values for injecting
> a program exception into the guest if we entered the function
> kvmppc_handle_exit_pr() with exit_nr = BOOK3S_INTERRUPT_PROGRAM.
> In other cases, the shadow_srr1 bits are zero. Since we want to
> pass an illegal-instruction program check to the guest, set
> "flags" to SRR1_PROGILL for these other cases.
> 
> Signed-off-by: Thomas Huth <thuth@redhat.com>
> ---
>  v2: Added a comment, as suggested by Alexander Graf
> 
>  arch/powerpc/kvm/book3s_pr.c | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
> index 95bceca..e67b8ea 100644
> --- a/arch/powerpc/kvm/book3s_pr.c
> +++ b/arch/powerpc/kvm/book3s_pr.c
> @@ -1031,7 +1031,17 @@ int kvmppc_handle_exit_pr(struct kvm_run *run, struct kvm_vcpu *vcpu,
>  		int emul;
>  
>  program_interrupt:
> -		flags = vcpu->arch.shadow_srr1 & 0x1f0000ull;
> +		/*
> +		 * shadow_srr1 only contains valid flags if we came here via
> +		 * a program exception. The other exceptions (emulation assist,
> +		 * FP unavailable, etc.) do not provide flags in SRR1, so use
> +		 * an illegal-instruction exception when injecting a program
> +		 * interrupt into the guest.
> +		 */
> +		if (exit_nr = BOOK3S_INTERRUPT_PROGRAM)
> +			flags = vcpu->arch.shadow_srr1 & 0x1f0000ull;
> +		else
> +			flags = SRR1_PROGILL;
>  
>  		emul = kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst);
>  		if (emul != EMULATE_DONE) {
> 

*ping*

 Thomas