| Message ID | 20210401150325.442125-43-npiggin@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | KVM: PPC: Book3S: C-ify the P9 entry/exit code | expand |
Excerpts from Nicholas Piggin's message of April 2, 2021 1:03 am: > The reflection of sc 1 hcalls from PR=1 userspace is required to support > PR KVM. Radix guests don't support PR KVM nor do they support nested > hash guests, so this sc 1 reflection can be removed from radix guests. > Cause a privileged program check instead, which is less surprising. I'm thinking twice about where to put this patch. This is kind of backwards (but also kind of not), so I decided instead to make the change to not reflect on radix in the patch that removes real mode hcall handlers from the P9 path. And the patch around this part of the series will introduce reflection for hash guest support in the P9 path. End result is the same but I think that works better. Thanks, Nick
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index ae5ad93a623f..f4d6ec6c4710 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -1403,11 +1403,20 @@ static int kvmppc_handle_exit_hv(struct kvm_vcpu *vcpu, int i; if (unlikely(vcpu->arch.shregs.msr & MSR_PR)) { - /* - * Guest userspace executed sc 1, reflect it back as a - * syscall as it may be a PR KVM hcall. - */ - kvmppc_core_queue_syscall(vcpu); + if (!kvmhv_vcpu_is_radix(vcpu)) { + /* + * Guest userspace executed sc 1, reflect it + * back as a syscall as it may be a PR KVM + * hcall. + */ + kvmppc_core_queue_syscall(vcpu); + } else { + /* + * radix guests can not run PR KVM so send a + * program check. + */ + kvmppc_core_queue_program(vcpu, SRR1_PROGPRIV); + } r = RESUME_GUEST; break; }
The reflection of sc 1 hcalls from PR=1 userspace is required to support PR KVM. Radix guests don't support PR KVM nor do they support nested hash guests, so this sc 1 reflection can be removed from radix guests. Cause a privileged program check instead, which is less surprising. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- arch/powerpc/kvm/book3s_hv.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-)