spapr: introduce routines to delete the KVM IRQ device

If a new interrupt mode is chosen by CAS, the machine generates a
reset to reconfigure. At this point, the connection with the previous
KVM device needs to be closed and a new connection needs to opened
with the KVM device operating the chosen interrupt mode.

New routines are introduced to destroy the XICS and the XIVE KVM
devices. They make use of a new KVM device ioctl which destroys the
device and also disconnects the IRQ presenters from the vCPUs.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20190513084245.25755-10-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

diff --git a/hw/intc/spapr_xive_kvm.c b/hw/intc/spapr_xive_kvm.c
index 3999e4b7edfb3840856f004deb2dd639aaaa595d..259cd1db958282554fcdd543ef4940a2641dd43a 100644 (file)
--- a/hw/intc/spapr_xive_kvm.c
+++ b/hw/intc/spapr_xive_kvm.c
@@ -58,6 +58,16 @@ static void kvm_cpu_enable(CPUState *cs)
     QLIST_INSERT_HEAD(&kvm_enabled_cpus, enabled_cpu, node);
 }
 
+static void kvm_cpu_disable_all(void)
+{
+    KVMEnabledCPU *enabled_cpu, *next;
+
+    QLIST_FOREACH_SAFE(enabled_cpu, &kvm_enabled_cpus, node, next) {
+        QLIST_REMOVE(enabled_cpu, node);
+        g_free(enabled_cpu);
+    }
+}
+
 /*
  * XIVE Thread Interrupt Management context (KVM)
  */
@@ -709,3 +719,49 @@ void kvmppc_xive_connect(SpaprXive *xive, Error **errp)
     /* Map all regions */
     spapr_xive_map_mmio(xive);
 }
+
+void kvmppc_xive_disconnect(SpaprXive *xive, Error **errp)
+{
+    XiveSource *xsrc;
+    size_t esb_len;
+
+    /* The KVM XIVE device is not in use */
+    if (!xive || xive->fd == -1) {
+        return;
+    }
+
+    if (!kvmppc_has_cap_xive()) {
+        error_setg(errp, "IRQ_XIVE capability must be present for KVM");
+        return;
+    }
+
+    /* Clear the KVM mapping */
+    xsrc = &xive->source;
+    esb_len = (1ull << xsrc->esb_shift) * xsrc->nr_irqs;
+
+    sysbus_mmio_unmap(SYS_BUS_DEVICE(xive), 0);
+    munmap(xsrc->esb_mmap, esb_len);
+
+    sysbus_mmio_unmap(SYS_BUS_DEVICE(xive), 1);
+
+    sysbus_mmio_unmap(SYS_BUS_DEVICE(xive), 2);
+    munmap(xive->tm_mmap, 4ull << TM_SHIFT);
+
+    /*
+     * When the KVM device fd is closed, the KVM device is destroyed
+     * and removed from the list of devices of the VM. The VCPU
+     * presenters are also detached from the device.
+     */
+    close(xive->fd);
+    xive->fd = -1;
+
+    kvm_kernel_irqchip = false;
+    kvm_msi_via_irqfd_allowed = false;
+    kvm_gsi_direct_mapping = false;
+
+    /* Clear the local list of presenter (hotplug) */
+    kvm_cpu_disable_all();
+
+    /* VM Change state handler is not needed anymore */
+    qemu_del_vm_change_state_handler(xive->change);
+}

diff --git a/hw/intc/xics_kvm.c b/hw/intc/xics_kvm.c
index 78a252e6dfd4c42620335fe9b7779dc53c6766f8..1185846ff183cef1f122e1c875baaf0b9b29e437 100644 (file)
--- a/hw/intc/xics_kvm.c
+++ b/hw/intc/xics_kvm.c
@@ -51,6 +51,16 @@ typedef struct KVMEnabledICP {
 static QLIST_HEAD(, KVMEnabledICP)
     kvm_enabled_icps = QLIST_HEAD_INITIALIZER(&kvm_enabled_icps);
 
+static void kvm_disable_icps(void)
+{
+    KVMEnabledICP *enabled_icp, *next;
+
+    QLIST_FOREACH_SAFE(enabled_icp, &kvm_enabled_icps, node, next) {
+        QLIST_REMOVE(enabled_icp, node);
+        g_free(enabled_icp);
+    }
+}
+
 /*
  * ICP-KVM
  */
@@ -360,3 +370,44 @@ fail:
     kvmppc_define_rtas_kernel_token(0, "ibm,int-off");
     return -1;
 }
+
+void xics_kvm_disconnect(SpaprMachineState *spapr, Error **errp)
+{
+    /* The KVM XICS device is not in use */
+    if (kernel_xics_fd == -1) {
+        return;
+    }
+
+    if (!kvm_enabled() || !kvm_check_extension(kvm_state, KVM_CAP_IRQ_XICS)) {
+        error_setg(errp,
+                   "KVM and IRQ_XICS capability must be present for KVM XICS device");
+        return;
+    }
+
+    /*
+     * Only on P9 using the XICS-on XIVE KVM device:
+     *
+     * When the KVM device fd is closed, the device is destroyed and
+     * removed from the list of devices of the VM. The VCPU presenters
+     * are also detached from the device.
+     */
+    close(kernel_xics_fd);
+    kernel_xics_fd = -1;
+
+    spapr_rtas_unregister(RTAS_IBM_SET_XIVE);
+    spapr_rtas_unregister(RTAS_IBM_GET_XIVE);
+    spapr_rtas_unregister(RTAS_IBM_INT_OFF);
+    spapr_rtas_unregister(RTAS_IBM_INT_ON);
+
+    kvmppc_define_rtas_kernel_token(0, "ibm,set-xive");
+    kvmppc_define_rtas_kernel_token(0, "ibm,get-xive");
+    kvmppc_define_rtas_kernel_token(0, "ibm,int-on");
+    kvmppc_define_rtas_kernel_token(0, "ibm,int-off");
+
+    kvm_kernel_irqchip = false;
+    kvm_msi_via_irqfd_allowed = false;
+    kvm_gsi_direct_mapping = false;
+
+    /* Clear the presenter from the VCPUs */
+    kvm_disable_icps();
+}

diff --git a/include/hw/ppc/spapr_xive.h b/include/hw/ppc/spapr_xive.h
index 04294b0ca26626ce6fafa153bf794721014bd50f..0b5e972d52c8e8f3d88917fcfec40d2e766c8b2e 100644 (file)
--- a/include/hw/ppc/spapr_xive.h
+++ b/include/hw/ppc/spapr_xive.h
@@ -71,6 +71,7 @@ int spapr_xive_end_to_target(uint8_t end_blk, uint32_t end_idx,
  * KVM XIVE device helpers
  */
 void kvmppc_xive_connect(SpaprXive *xive, Error **errp);
+void kvmppc_xive_disconnect(SpaprXive *xive, Error **errp);
 void kvmppc_xive_reset(SpaprXive *xive, Error **errp);
 void kvmppc_xive_set_source_config(SpaprXive *xive, uint32_t lisn, XiveEAS *eas,
                                    Error **errp);

diff --git a/include/hw/ppc/xics_spapr.h b/include/hw/ppc/xics_spapr.h
index 15a8dcff66fc0fb77593a27cfb7ff81115777401..2476b540edfa302c855105195299e08cf3b3fb82 100644 (file)
--- a/include/hw/ppc/xics_spapr.h
+++ b/include/hw/ppc/xics_spapr.h
@@ -34,6 +34,7 @@
 void spapr_dt_xics(SpaprMachineState *spapr, uint32_t nr_servers, void *fdt,
                    uint32_t phandle);
 int xics_kvm_init(SpaprMachineState *spapr, Error **errp);
+void xics_kvm_disconnect(SpaprMachineState *spapr, Error **errp);
 void xics_spapr_init(SpaprMachineState *spapr);
 
 #endif /* XICS_SPAPR_H */