KVM: PPC: Book3S HV: XIVE: Do not test the EQ flag validity when resetting

When a CPU is hot-unplugged, the EQ is deconfigured using a zero size
and a zero address. In this case, there is no need to check the flag
and queue size validity. Move the checks after the queue reset code
section to fix CPU hot-unplug.

Reported-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Tested-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

diff --git a/arch/powerpc/kvm/book3s_xive_native.c b/arch/powerpc/kvm/book3s_xive_native.c
index 9cedd04e7a4493094252feffa0fe4864b05190e6..53b7159dc3058c277b4119163549f6d51e35e52b 100644 (file)
--- a/arch/powerpc/kvm/book3s_xive_native.c
+++ b/arch/powerpc/kvm/book3s_xive_native.c
@@ -565,24 +565,6 @@ static int kvmppc_xive_native_set_queue_config(struct kvmppc_xive *xive,
                 __func__, server, priority, kvm_eq.flags,
                 kvm_eq.qshift, kvm_eq.qaddr, kvm_eq.qtoggle, kvm_eq.qindex);
 
-       /*
-        * sPAPR specifies a "Unconditional Notify (n) flag" for the
-        * H_INT_SET_QUEUE_CONFIG hcall which forces notification
-        * without using the coalescing mechanisms provided by the
-        * XIVE END ESBs. This is required on KVM as notification
-        * using the END ESBs is not supported.
-        */
-       if (kvm_eq.flags != KVM_XIVE_EQ_ALWAYS_NOTIFY) {
-               pr_err("invalid flags %d\n", kvm_eq.flags);
-               return -EINVAL;
-       }
-
-       rc = xive_native_validate_queue_size(kvm_eq.qshift);
-       if (rc) {
-               pr_err("invalid queue size %d\n", kvm_eq.qshift);
-               return rc;
-       }
-
        /* reset queue and disable queueing */
        if (!kvm_eq.qshift) {
                q->guest_qaddr  = 0;
@@ -604,6 +586,24 @@ static int kvmppc_xive_native_set_queue_config(struct kvmppc_xive *xive,
                return 0;
        }
 
+       /*
+        * sPAPR specifies a "Unconditional Notify (n) flag" for the
+        * H_INT_SET_QUEUE_CONFIG hcall which forces notification
+        * without using the coalescing mechanisms provided by the
+        * XIVE END ESBs. This is required on KVM as notification
+        * using the END ESBs is not supported.
+        */
+       if (kvm_eq.flags != KVM_XIVE_EQ_ALWAYS_NOTIFY) {
+               pr_err("invalid flags %d\n", kvm_eq.flags);
+               return -EINVAL;
+       }
+
+       rc = xive_native_validate_queue_size(kvm_eq.qshift);
+       if (rc) {
+               pr_err("invalid queue size %d\n", kvm_eq.qshift);
+               return rc;
+       }
+
        if (kvm_eq.qaddr & ((1ull << kvm_eq.qshift) - 1)) {
                pr_err("queue page is not aligned %llx/%llx\n", kvm_eq.qaddr,
                       1ull << kvm_eq.qshift);