Patch "KVM: PPC: Book3S HV: Fix pending_pri value in kvmppc_xive_get_icp()" has been added to the 4.14-stable tree

This is a note to let you know that I've just added the patch titled

KVM: PPC: Book3S HV: Fix pending_pri value in kvmppc_xive_get_icp()

to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
kvm-ppc-book3s-hv-fix-pending_pri-value-in-kvmppc_xive_get_icp.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Laurent Vivier <[email protected]>
Date: Tue, 12 Dec 2017 18:23:56 +0100
Subject: KVM: PPC: Book3S HV: Fix pending_pri value in kvmppc_xive_get_icp()

From: Laurent Vivier <[email protected]>

commit 7333b5aca412d6ad02667b5a513485838a91b136 upstream.

When we migrate a VM from a POWER8 host (XICS) to a POWER9 host (XICS-on-XIVE), we have an error:

qemu-kvm: Unable to restore KVM interrupt controller state \

          (0xff000000) for CPU 0: Invalid argument

This is because kvmppc_xics_set_icp() checks the new state is internaly consistent, and especially:

...
1129 if (xisr == 0) {
1130 if (pending_pri != 0xff)
1131 return -EINVAL;
...

On the other side, kvmppc_xive_get_icp() doesn't set neither the pending_pri value, nor the xisr value (set to 0) (and kvmppc_xive_set_icp() ignores the pending_pri value)

As xisr is 0, pending_pri must be set to 0xff.

---
 arch/powerpc/kvm/book3s_xive.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

@@ -725,7 +725,8 @@ u64 kvmppc_xive_get_icp(struct kvm_vcpu
 
 	/* Return the per-cpu state for state saving/migration */
 	return (u64)xc->cppr << KVM_REG_PPC_ICP_CPPR_SHIFT |
-	       (u64)xc->mfrr << KVM_REG_PPC_ICP_MFRR_SHIFT;
+	       (u64)xc->mfrr << KVM_REG_PPC_ICP_MFRR_SHIFT |
+	       (u64)0xff << KVM_REG_PPC_ICP_PPRI_SHIFT;
 }
 
 int kvmppc_xive_set_icp(struct kvm_vcpu *vcpu, u64 icpval)

Patches currently in stable-queue which might be from [email protected] are

queue-4.14/kvm-ppc-book3s-hv-fix-pending_pri-value-in-kvmppc_xive_get_icp.patch queue-4.14/kvm-ppc-book3s-fix-xive-migration-of-pending-interrupts.patch