Re: [PATCH] KVM: PPC: Book3S HV: relax check on H_SVM_INIT_ABORT

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Le 20/05/2020 à 19:32, Greg Kurz a écrit :
On Wed, 20 May 2020 18:51:10 +0200
Laurent Dufour <ldufour@xxxxxxxxxxxxx> wrote:

The commit 8c47b6ff29e3 ("KVM: PPC: Book3S HV: Check caller of H_SVM_*
Hcalls") added checks of secure bit of SRR1 to filter out the Hcall
reserved to the Ultravisor.

However, the Hcall H_SVM_INIT_ABORT is made by the Ultravisor passing the
context of the VM calling UV_ESM. This allows the Hypervisor to return to
the guest without going through the Ultravisor. Thus the Secure bit of SRR1
is not set in that particular case.

In the case a regular VM is calling H_SVM_INIT_ABORT, this hcall will be
filtered out in kvmppc_h_svm_init_abort() because kvm->arch.secure_guest is
not set in that case.


Why not checking vcpu->kvm->arch.secure_guest then ?

I don't think that's the right place.

Fixes: 8c47b6ff29e3 ("KVM: PPC: Book3S HV: Check caller of H_SVM_* Hcalls")
Signed-off-by: Laurent Dufour <ldufour@xxxxxxxxxxxxx>
---
  arch/powerpc/kvm/book3s_hv.c | 4 +---
  1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 93493f0cbfe8..eb1f96cb7b72 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -1099,9 +1099,7 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
  			ret = kvmppc_h_svm_init_done(vcpu->kvm);
  		break;
  	case H_SVM_INIT_ABORT:
-		ret = H_UNSUPPORTED;
-		if (kvmppc_get_srr1(vcpu) & MSR_S)
-			ret = kvmppc_h_svm_init_abort(vcpu->kvm);

or at least put a comment to explain why H_SVM_INIT_ABORT
doesn't have the same sanity check as the other SVM hcalls.

I agree that might help. I'll send a v2 with a comment there.


+		ret = kvmppc_h_svm_init_abort(vcpu->kvm);
  		break;
default:





[Index of Archives]     [KVM Development]     [KVM ARM]     [KVM ia64]     [Linux Virtualization]     [Linux USB Devel]     [Linux Video]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [Big List of Linux Books]

  Powered by Linux