Merge remote-tracking branch 'qemu-kvm/uq/master' into staging

* qemu-kvm/uq/master:
  kvm: Add documentation comment for kvm_irqchip_in_kernel()
  kvm: Decouple 'GSI routing' from 'kernel irqchip'
  kvm: Decouple 'MSI routing via irqfds' from 'kernel irqchip'
  kvm: Decouple 'irqfds usable' from 'kernel irqchip'
  kvm: Move kvm_allows_irq0_override() to target-i386, fix return type
  kvm: Rename kvm_irqchip_set_irq() to kvm_set_irq()
  kvm: Decouple 'async interrupt delivery' from 'kernel irqchip'
  configure: Don't implicitly hardcode list of KVM architectures
  kvm: Check if smp_cpus exceeds max cpus supported by kvm

13 files changed, 170 insertions, 27 deletions

diff --git a/configure b/configure
index f0dbc03af2..97b69a0d73 100755
--- a/configure
+++ b/configure
@@ -3563,15 +3563,23 @@ if test "$linux" = "yes" ; then
   mkdir -p linux-headers
   case "$cpu" in
   i386|x86_64)
-    symlink "$source_path/linux-headers/asm-x86" linux-headers/asm
+    linux_arch=x86
     ;;
   ppcemb|ppc|ppc64)
-    symlink "$source_path/linux-headers/asm-powerpc" linux-headers/asm
+    linux_arch=powerpc
     ;;
   s390x)
-    symlink "$source_path/linux-headers/asm-s390" linux-headers/asm
+    linux_arch=s390
+    ;;
+  *)
+    # For most CPUs the kernel architecture name and QEMU CPU name match.
+    linux_arch="$cpu"
     ;;
   esac
+    # For non-KVM architectures we will not have asm headers
+    if [ -e "$source_path/linux-headers/asm-$linux_arch" ]; then
+      symlink "$source_path/linux-headers/asm-$linux_arch" linux-headers/asm
+    fi
 fi
 
 for target in $target_list; do
diff --git a/cpus.c b/cpus.c
index 3de2e27f41..e476a3cd5e 100644
--- a/cpus.c
+++ b/cpus.c
@@ -70,7 +70,8 @@ static bool cpu_thread_is_idle(CPUArchState *env)
     if (env->stopped || !runstate_is_running()) {
         return true;
     }
-    if (!env->halted || qemu_cpu_has_work(env) || kvm_irqchip_in_kernel()) {
+    if (!env->halted || qemu_cpu_has_work(env) ||
+        kvm_async_interrupts_enabled()) {
         return false;
     }
     return true;
diff --git a/hw/kvm/i8259.c b/hw/kvm/i8259.c
index 94d1b9aa95..1e24cd4f36 100644
--- a/hw/kvm/i8259.c
+++ b/hw/kvm/i8259.c
@@ -94,7 +94,7 @@ static void kvm_pic_set_irq(void *opaque, int irq, int level)
 {
     int delivered;
 
-    delivered = kvm_irqchip_set_irq(kvm_state, irq, level);
+    delivered = kvm_set_irq(kvm_state, irq, level);
     apic_report_irq_delivered(delivered);
 }
 
diff --git a/hw/kvm/ioapic.c b/hw/kvm/ioapic.c
index 3ae3175403..6c3b8fe39a 100644
--- a/hw/kvm/ioapic.c
+++ b/hw/kvm/ioapic.c
@@ -82,7 +82,7 @@ static void kvm_ioapic_set_irq(void *opaque, int irq, int level)
     KVMIOAPICState *s = opaque;
     int delivered;
 
-    delivered = kvm_irqchip_set_irq(kvm_state, s->kvm_gsi_base + irq, level);
+    delivered = kvm_set_irq(kvm_state, s->kvm_gsi_base + irq, level);
     apic_report_irq_delivered(delivered);
 }
 
diff --git a/hw/pc.c b/hw/pc.c
index 81c391cd6a..e8bcfc0b4b 100644
--- a/hw/pc.c
+++ b/hw/pc.c
@@ -42,6 +42,7 @@
 #include "sysbus.h"
 #include "sysemu.h"
 #include "kvm.h"
+#include "kvm_i386.h"
 #include "xen.h"
 #include "blockdev.h"
 #include "hw/block-common.h"
diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c
index 125eded9ca..5e6e09efb7 100644
--- a/hw/virtio-pci.c
+++ b/hw/virtio-pci.c
@@ -627,7 +627,7 @@ static int virtio_pci_set_guest_notifiers(void *opaque, bool assign)
     int r, n;
 
     /* Must unset vector notifier while guest notifier is still assigned */
-    if (kvm_irqchip_in_kernel() && !assign) {
+    if (kvm_msi_via_irqfd_enabled() && !assign) {
         msix_unset_vector_notifiers(&proxy->pci_dev);
         g_free(proxy->vector_irqfd);
         proxy->vector_irqfd = NULL;
@@ -645,7 +645,7 @@ static int virtio_pci_set_guest_notifiers(void *opaque, bool assign)
     }
 
     /* Must set vector notifier after guest notifier has been assigned */
-    if (kvm_irqchip_in_kernel() && assign) {
+    if (kvm_msi_via_irqfd_enabled() && assign) {
         proxy->vector_irqfd =
             g_malloc0(sizeof(*proxy->vector_irqfd) *
                       msix_nr_vectors_allocated(&proxy->pci_dev));
diff --git a/kvm-all.c b/kvm-all.c
index 2148b20bdb..34b02c1fba 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -100,6 +100,10 @@ struct KVMState
 
 KVMState *kvm_state;
 bool kvm_kernel_irqchip;
+bool kvm_async_interrupts_allowed;
+bool kvm_irqfds_allowed;
+bool kvm_msi_via_irqfd_allowed;
+bool kvm_gsi_routing_allowed;
 
 static const KVMCapabilityInfo kvm_required_capabilites[] = {
     KVM_CAP_INFO(USER_MEMORY),
@@ -852,18 +856,18 @@ static void kvm_handle_interrupt(CPUArchState *env, int mask)
     }
 }
 
-int kvm_irqchip_set_irq(KVMState *s, int irq, int level)
+int kvm_set_irq(KVMState *s, int irq, int level)
 {
     struct kvm_irq_level event;
     int ret;
 
-    assert(kvm_irqchip_in_kernel());
+    assert(kvm_async_interrupts_enabled());
 
     event.level = level;
     event.irq = irq;
     ret = kvm_vm_ioctl(s, s->irqchip_inject_ioctl, &event);
     if (ret < 0) {
-        perror("kvm_set_irqchip_line");
+        perror("kvm_set_irq");
         abort();
     }
 
@@ -1088,7 +1092,7 @@ int kvm_irqchip_send_msi(KVMState *s, MSIMessage msg)
 
     assert(route->kroute.type == KVM_IRQ_ROUTING_MSI);
 
-    return kvm_irqchip_set_irq(s, route->kroute.gsi, 1);
+    return kvm_set_irq(s, route->kroute.gsi, 1);
 }
 
 int kvm_irqchip_add_msi_route(KVMState *s, MSIMessage msg)
@@ -1096,7 +1100,7 @@ int kvm_irqchip_add_msi_route(KVMState *s, MSIMessage msg)
     struct kvm_irq_routing_entry kroute;
     int virq;
 
-    if (!kvm_irqchip_in_kernel()) {
+    if (!kvm_gsi_routing_enabled()) {
         return -ENOSYS;
     }
 
@@ -1125,7 +1129,7 @@ static int kvm_irqchip_assign_irqfd(KVMState *s, int fd, int virq, bool assign)
         .flags = assign ? 0 : KVM_IRQFD_FLAG_DEASSIGN,
     };
 
-    if (!kvm_irqchip_in_kernel()) {
+    if (!kvm_irqfds_enabled()) {
         return -ENOSYS;
     }
 
@@ -1201,12 +1205,36 @@ static int kvm_irqchip_create(KVMState *s)
         s->irqchip_inject_ioctl = KVM_IRQ_LINE_STATUS;
     }
     kvm_kernel_irqchip = true;
+    /* If we have an in-kernel IRQ chip then we must have asynchronous
+     * interrupt delivery (though the reverse is not necessarily true)
+     */
+    kvm_async_interrupts_allowed = true;
 
     kvm_init_irq_routing(s);
 
     return 0;
 }
 
+static int kvm_max_vcpus(KVMState *s)
+{
+    int ret;
+
+    /* Find number of supported CPUs using the recommended
+     * procedure from the kernel API documentation to cope with
+     * older kernels that may be missing capabilities.
+     */
+    ret = kvm_check_extension(s, KVM_CAP_MAX_VCPUS);
+    if (ret) {
+        return ret;
+    }
+    ret = kvm_check_extension(s, KVM_CAP_NR_VCPUS);
+    if (ret) {
+        return ret;
+    }
+
+    return 4;
+}
+
 int kvm_init(void)
 {
     static const char upgrade_note[] =
@@ -1216,6 +1244,7 @@ int kvm_init(void)
     const KVMCapabilityInfo *missing_cap;
     int ret;
     int i;
+    int max_vcpus;
 
     s = g_malloc0(sizeof(KVMState));
 
@@ -1256,6 +1285,14 @@ int kvm_init(void)
         goto err;
     }
 
+    max_vcpus = kvm_max_vcpus(s);
+    if (smp_cpus > max_vcpus) {
+        ret = -EINVAL;
+        fprintf(stderr, "Number of SMP cpus requested (%d) exceeds max cpus "
+                "supported by KVM (%d)\n", smp_cpus, max_vcpus);
+        goto err;
+    }
+
     s->vmfd = kvm_ioctl(s, KVM_CREATE_VM, 0);
     if (s->vmfd < 0) {
 #ifdef TARGET_S390X
@@ -1667,11 +1704,6 @@ int kvm_has_gsi_routing(void)
 #endif
 }
 
-int kvm_allows_irq0_override(void)
-{
-    return !kvm_irqchip_in_kernel() || kvm_has_gsi_routing();
-}
-
 void *kvm_vmalloc(ram_addr_t size)
 {
 #ifdef TARGET_S390X
diff --git a/kvm-stub.c b/kvm-stub.c
index d23b11c020..94c9ea15b0 100644
--- a/kvm-stub.c
+++ b/kvm-stub.c
@@ -19,6 +19,10 @@
 
 KVMState *kvm_state;
 bool kvm_kernel_irqchip;
+bool kvm_async_interrupts_allowed;
+bool kvm_irqfds_allowed;
+bool kvm_msi_via_irqfd_allowed;
+bool kvm_gsi_routing_allowed;
 
 int kvm_init_vcpu(CPUArchState *env)
 {
@@ -71,11 +75,6 @@ int kvm_has_many_ioeventfds(void)
     return 0;
 }
 
-int kvm_allows_irq0_override(void)
-{
-    return 1;
-}
-
 int kvm_has_pit_state2(void)
 {
     return 0;
diff --git a/kvm.h b/kvm.h
index 2617dd5acd..5b8f588813 100644
--- a/kvm.h
+++ b/kvm.h
@@ -24,13 +24,69 @@
 
 extern int kvm_allowed;
 extern bool kvm_kernel_irqchip;
+extern bool kvm_async_interrupts_allowed;
+extern bool kvm_irqfds_allowed;
+extern bool kvm_msi_via_irqfd_allowed;
+extern bool kvm_gsi_routing_allowed;
 
 #if defined CONFIG_KVM || !defined NEED_CPU_H
 #define kvm_enabled()           (kvm_allowed)
+/**
+ * kvm_irqchip_in_kernel:
+ *
+ * Returns: true if the user asked us to create an in-kernel
+ * irqchip via the "kernel_irqchip=on" machine option.
+ * What this actually means is architecture and machine model
+ * specific: on PC, for instance, it means that the LAPIC,
+ * IOAPIC and PIT are all in kernel. This function should never
+ * be used from generic target-independent code: use one of the
+ * following functions or some other specific check instead.
+ */
 #define kvm_irqchip_in_kernel() (kvm_kernel_irqchip)
+
+/**
+ * kvm_async_interrupts_enabled:
+ *
+ * Returns: true if we can deliver interrupts to KVM
+ * asynchronously (ie by ioctl from any thread at any time)
+ * rather than having to do interrupt delivery synchronously
+ * (where the vcpu must be stopped at a suitable point first).
+ */
+#define kvm_async_interrupts_enabled() (kvm_async_interrupts_allowed)
+
+/**
+ * kvm_irqfds_enabled:
+ *
+ * Returns: true if we can use irqfds to inject interrupts into
+ * a KVM CPU (ie the kernel supports irqfds and we are running
+ * with a configuration where it is meaningful to use them).
+ */
+#define kvm_irqfds_enabled() (kvm_irqfds_allowed)
+
+/**
+ * kvm_msi_via_irqfd_enabled:
+ *
+ * Returns: true if we can route a PCI MSI (Message Signaled Interrupt)
+ * to a KVM CPU via an irqfd. This requires that the kernel supports
+ * this and that we're running in a configuration that permits it.
+ */
+#define kvm_msi_via_irqfd_enabled() (kvm_msi_via_irqfd_allowed)
+
+/**
+ * kvm_gsi_routing_enabled:
+ *
+ * Returns: true if GSI routing is enabled (ie the kernel supports
+ * it and we're running in a configuration that permits it).
+ */
+#define kvm_gsi_routing_enabled() (kvm_gsi_routing_allowed)
+
 #else
 #define kvm_enabled()           (0)
 #define kvm_irqchip_in_kernel() (false)
+#define kvm_async_interrupts_enabled() (false)
+#define kvm_irqfds_enabled() (false)
+#define kvm_msi_via_irqfd_enabled() (false)
+#define kvm_gsi_routing_allowed() (false)
 #endif
 
 struct kvm_run;
@@ -62,8 +118,6 @@ int kvm_has_pit_state2(void);
 int kvm_has_many_ioeventfds(void);
 int kvm_has_gsi_routing(void);
 
-int kvm_allows_irq0_override(void);
-
 #ifdef NEED_CPU_H
 int kvm_init_vcpu(CPUArchState *env);
 
@@ -133,7 +187,7 @@ int kvm_arch_on_sigbus(int code, void *addr);
 
 void kvm_arch_init_irq_routing(KVMState *s);
 
-int kvm_irqchip_set_irq(KVMState *s, int irq, int level);
+int kvm_set_irq(KVMState *s, int irq, int level);
 int kvm_irqchip_send_msi(KVMState *s, MSIMessage msg);
 
 void kvm_irqchip_add_irq_route(KVMState *s, int gsi, int irqchip, int pin);
diff --git a/target-i386/Makefile.objs b/target-i386/Makefile.objs
index 683fd59af9..0715f58a8e 100644
--- a/target-i386/Makefile.objs
+++ b/target-i386/Makefile.objs
@@ -3,6 +3,7 @@ obj-y += excp_helper.o fpu_helper.o cc_helper.o int_helper.o svm_helper.o
 obj-y += smm_helper.o misc_helper.o mem_helper.o seg_helper.o
 obj-$(CONFIG_SOFTMMU) += machine.o arch_memory_mapping.o arch_dump.o
 obj-$(CONFIG_KVM) += kvm.o hyperv.o
+obj-$(CONFIG_NO_KVM) += kvm-stub.o
 obj-$(CONFIG_LINUX_USER) += ioport-user.o
 obj-$(CONFIG_BSD_USER) += ioport-user.o
 
diff --git a/target-i386/kvm-stub.c b/target-i386/kvm-stub.c
new file mode 100644
index 0000000000..11429c461e
--- /dev/null
+++ b/target-i386/kvm-stub.c
@@ -0,0 +1,18 @@
+/*
+ * QEMU KVM x86 specific function stubs
+ *
+ * Copyright Linaro Limited 2012
+ *
+ * Author: Peter Maydell <peter.maydell@linaro.org>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+#include "qemu-common.h"
+#include "kvm_i386.h"
+
+bool kvm_allows_irq0_override(void)
+{
+    return 1;
+}
diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index 4cfb3faf01..696b14a04a 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -23,6 +23,7 @@
 #include "qemu-common.h"
 #include "sysemu.h"
 #include "kvm.h"
+#include "kvm_i386.h"
 #include "cpu.h"
 #include "gdbstub.h"
 #include "host-utils.h"
@@ -65,6 +66,11 @@ static bool has_msr_async_pf_en;
 static bool has_msr_misc_enable;
 static int lm_capable_kernel;
 
+bool kvm_allows_irq0_override(void)
+{
+    return !kvm_irqchip_in_kernel() || kvm_has_gsi_routing();
+}
+
 static struct kvm_cpuid2 *try_get_cpuid(KVMState *s, int max)
 {
     struct kvm_cpuid2 *cpuid;
@@ -2041,4 +2047,11 @@ void kvm_arch_init_irq_routing(KVMState *s)
          */
         no_hpet = 1;
     }
+    /* We know at this point that we're using the in-kernel
+     * irqchip, so we can use irqfds, and on x86 we know
+     * we can use msi via irqfd and GSI routing.
+     */
+    kvm_irqfds_allowed = true;
+    kvm_msi_via_irqfd_allowed = true;
+    kvm_gsi_routing_allowed = true;
 }
diff --git a/target-i386/kvm_i386.h b/target-i386/kvm_i386.h
new file mode 100644
index 0000000000..b82bbf401e
--- /dev/null
+++ b/target-i386/kvm_i386.h
@@ -0,0 +1,16 @@
+/*
+ * QEMU KVM support -- x86 specific functions.
+ *
+ * Copyright (c) 2012 Linaro Limited
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#ifndef QEMU_KVM_I386_H
+#define QEMU_KVM_I386_H
+
+bool kvm_allows_irq0_override(void);
+
+#endif