KVM: arm64: Allow no running vcpu on restoring vgic3 LPI pending status

We don't have a running VCPU context to restore vgic3 LPI pending status
due to command KVM_DEV_ARM_{VGIC_GRP_CTRL, ITS_RESTORE_TABLES} on KVM
device "kvm-arm-vgic-its".

Use vgic_write_guest_lock() to restore vgic3 LPI pending status.

Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230126235451.469087-4-gshan@redhat.com

diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index dbed78a..25e9095 100644 (file)
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -8070,9 +8070,11 @@ considering the state as complete. VMM needs to ensure that the dirty
 state is final and avoid missing dirty pages from another ioctl ordered
 after the bitmap collection.
 
-NOTE: One example of using the backup bitmap is saving arm64 vgic/its
-tables through KVM_DEV_ARM_{VGIC_GRP_CTRL, ITS_SAVE_TABLES} command on
-KVM device "kvm-arm-vgic-its" when dirty ring is enabled.
+NOTE: Multiple examples of using the backup bitmap: (1) save vgic/its
+tables through command KVM_DEV_ARM_{VGIC_GRP_CTRL, ITS_SAVE_TABLES} on
+KVM device "kvm-arm-vgic-its". (2) restore vgic/its tables through
+command KVM_DEV_ARM_{VGIC_GRP_CTRL, ITS_RESTORE_TABLES} on KVM device
+"kvm-arm-vgic-its". VGICv3 LPI pending status is restored.
 
 8.30 KVM_CAP_XEN_HVM
 --------------------

diff --git a/arch/arm64/kvm/vgic/vgic-v3.c b/arch/arm64/kvm/vgic/vgic-v3.c
index 2624963..3dab286 100644 (file)
--- a/arch/arm64/kvm/vgic/vgic-v3.c
+++ b/arch/arm64/kvm/vgic/vgic-v3.c
@@ -339,7 +339,7 @@ retry:
        if (status) {
                /* clear consumed data */
                val &= ~(1 << bit_nr);
-               ret = kvm_write_guest_lock(kvm, ptr, &val, 1);
+               ret = vgic_write_guest_lock(kvm, ptr, &val, 1);
                if (ret)
                        return ret;
        }