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%3Ba=su...
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 stable@vger.kernel.org know about it.
From 7333b5aca412d6ad02667b5a513485838a91b136 Mon Sep 17 00:00:00 2001
From: Laurent Vivier lvivier@redhat.com 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 lvivier@redhat.com
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.
Fixes: 5af50993850a ("KVM: PPC: Book3S HV: Native usage of the XIVE interrupt controller") Signed-off-by: Laurent Vivier lvivier@redhat.com Acked-by: Benjamin Herrenschmidt benh@kernel.crashing.org Signed-off-by: Michael Ellerman mpe@ellerman.id.au Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/powerpc/kvm/book3s_xive.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/arch/powerpc/kvm/book3s_xive.c +++ b/arch/powerpc/kvm/book3s_xive.c @@ -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 lvivier@redhat.com 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