[Qemu-devel] [PATCH v4 0/8] uq/master: MSI support for in-kernel irqchip mode

[Qemu-devel] [PATCH v4 0/8] uq/master: MSI support for in-kernel irqchip mode

[Jan Kiszka]

Only minor change in v4:
 - fixed bisectability issue caused by "pc: Enable MSI support at APIC
   level"
 - renamed kvm_get_pseudo_gsi to kvm_irqchip_get_virq
 - introduce kvm_irqchip_release_virq directly (to avoid renaming in a
   later series)

Jan Kiszka (8):
  kvm: Refactor KVMState::max_gsi to gsi_count
  Introduce MSIMessage structure
  kvm: Introduce basic MSI support for in-kernel irqchips
  pc: Enable MSI support at APIC level
  kvm: x86: Wire up MSI support for in-kernel irqchip
  kvm: Update kernel headers
  kvm: Add support for direct MSI injections
  kvm: Enable in-kernel irqchip support by default

 hw/apic.c                 |    3 +
 hw/kvm/apic.c             |   34 +++++++++-
 hw/msi.h                  |    5 ++
 hw/pc.c                   |    9 ---
 hw/xen.h                  |   10 ---
 hw/xen_apic.c             |    5 ++
 kvm-all.c                 |  165 +++++++++++++++++++++++++++++++++++++++++++--
 kvm.h                     |    1 +
 linux-headers/linux/kvm.h |   38 ++++++++++
 qemu-common.h             |    1 +
 10 files changed, 244 insertions(+), 27 deletions(-)

-- 
1.7.3.4

[Qemu-devel] [PATCH v4 1/8] kvm: Refactor KVMState::max_gsi to gsi_count

[Jan Kiszka]

Instead of the bitmap size, store the maximum of GSIs the kernel
support. Move the GSI limit assertion to the API function
kvm_irqchip_add_route and make it stricter.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 kvm-all.c |    8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/kvm-all.c b/kvm-all.c
index 9b73ccf..2d82d54 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -86,7 +86,7 @@ struct KVMState
     struct kvm_irq_routing *irq_routes;
     int nr_allocated_irq_routes;
     uint32_t *used_gsi_bitmap;
-    unsigned int max_gsi;
+    unsigned int gsi_count;
 #endif
 };
 
@@ -859,8 +859,6 @@ int kvm_irqchip_set_irq(KVMState *s, int irq, int level)
 #ifdef KVM_CAP_IRQ_ROUTING
 static void set_gsi(KVMState *s, unsigned int gsi)
 {
-    assert(gsi < s->max_gsi);
-
     s->used_gsi_bitmap[gsi / 32] |= 1U << (gsi % 32);
 }
 
@@ -875,7 +873,7 @@ static void kvm_init_irq_routing(KVMState *s)
         /* Round up so we can search ints using ffs */
         gsi_bits = ALIGN(gsi_count, 32);
         s->used_gsi_bitmap = g_malloc0(gsi_bits / 8);
-        s->max_gsi = gsi_bits;
+        s->gsi_count = gsi_count;
 
         /* Mark any over-allocated bits as already in use */
         for (i = gsi_count; i < gsi_bits; i++) {
@@ -920,6 +918,8 @@ void kvm_irqchip_add_route(KVMState *s, int irq, int irqchip, int pin)
 {
     struct kvm_irq_routing_entry e;
 
+    assert(pin < s->gsi_count);
+
     e.gsi = irq;
     e.type = KVM_IRQ_ROUTING_IRQCHIP;
     e.flags = 0;
-- 
1.7.3.4

[Qemu-devel] [PATCH v4 2/8] Introduce MSIMessage structure

[Jan Kiszka]

Will be used for generating and distributing MSI messages, both in
emulation mode and under KVM.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 hw/msi.h      |    5 +++++
 qemu-common.h |    1 +
 2 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/hw/msi.h b/hw/msi.h
index 3040bb0..75747ab 100644
--- a/hw/msi.h
+++ b/hw/msi.h
@@ -24,6 +24,11 @@
 #include "qemu-common.h"
 #include "pci.h"
 
+struct MSIMessage {
+    uint64_t address;
+    uint32_t data;
+};
+
 extern bool msi_supported;
 
 bool msi_enabled(const PCIDevice *dev);
diff --git a/qemu-common.h b/qemu-common.h
index 50f659a..57fe28f 100644
--- a/qemu-common.h
+++ b/qemu-common.h
@@ -248,6 +248,7 @@ typedef struct PCIEAERLog PCIEAERLog;
 typedef struct PCIEAERErr PCIEAERErr;
 typedef struct PCIEPort PCIEPort;
 typedef struct PCIESlot PCIESlot;
+typedef struct MSIMessage MSIMessage;
 typedef struct SerialState SerialState;
 typedef struct IRQState *qemu_irq;
 typedef struct PCMCIACardState PCMCIACardState;
-- 
1.7.3.4

[Qemu-devel] [PATCH v4 3/8] kvm: Introduce basic MSI support for in-kernel irqchips

[Jan Kiszka]

This patch basically adds kvm_irqchip_send_msi, a service for sending
arbitrary MSI messages to KVM's in-kernel irqchip models.

As the original KVM API requires us to establish a static route from a
pseudo GSI to the target MSI message and inject the MSI via toggling
that virtual IRQ, we need to play some tricks to make this interface
transparent. We create those routes on demand and keep them in a hash
table. Succeeding messages can then search for an existing route in the
table first and reuse it whenever possible. If we should run out of
limited GSIs, we simply flush the table and rebuild it as messages are
sent.

This approach is rather simple and could be optimized further. However,
latest kernels contains a more efficient MSI injection interface that
will obsolete the GSI-based dynamic injection.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 kvm-all.c |  139 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 kvm.h     |    1 +
 2 files changed, 139 insertions(+), 1 deletions(-)

diff --git a/kvm-all.c b/kvm-all.c
index 2d82d54..ff0534b 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -24,6 +24,7 @@
 #include "qemu-barrier.h"
 #include "sysemu.h"
 #include "hw/hw.h"
+#include "hw/msi.h"
 #include "gdbstub.h"
 #include "kvm.h"
 #include "bswap.h"
@@ -48,6 +49,8 @@
     do { } while (0)
 #endif
 
+#define KVM_MSI_HASHTAB_SIZE    256
+
 typedef struct KVMSlot
 {
     target_phys_addr_t start_addr;
@@ -59,6 +62,11 @@ typedef struct KVMSlot
 
 typedef struct kvm_dirty_log KVMDirtyLog;
 
+typedef struct KVMMSIRoute {
+    struct kvm_irq_routing_entry kroute;
+    QTAILQ_ENTRY(KVMMSIRoute) entry;
+} KVMMSIRoute;
+
 struct KVMState
 {
     KVMSlot slots[32];
@@ -87,6 +95,7 @@ struct KVMState
     int nr_allocated_irq_routes;
     uint32_t *used_gsi_bitmap;
     unsigned int gsi_count;
+    QTAILQ_HEAD(msi_hashtab, KVMMSIRoute) msi_hashtab[KVM_MSI_HASHTAB_SIZE];
 #endif
 };
 
@@ -862,9 +871,14 @@ static void set_gsi(KVMState *s, unsigned int gsi)
     s->used_gsi_bitmap[gsi / 32] |= 1U << (gsi % 32);
 }
 
+static void clear_gsi(KVMState *s, unsigned int gsi)
+{
+    s->used_gsi_bitmap[gsi / 32] &= ~(1U << (gsi % 32));
+}
+
 static void kvm_init_irq_routing(KVMState *s)
 {
-    int gsi_count;
+    int gsi_count, i;
 
     gsi_count = kvm_check_extension(s, KVM_CAP_IRQ_ROUTING);
     if (gsi_count > 0) {
@@ -884,6 +898,10 @@ static void kvm_init_irq_routing(KVMState *s)
     s->irq_routes = g_malloc0(sizeof(*s->irq_routes));
     s->nr_allocated_irq_routes = 0;
 
+    for (i = 0; i < KVM_MSI_HASHTAB_SIZE; i++) {
+        QTAILQ_INIT(&s->msi_hashtab[i]);
+    }
+
     kvm_arch_init_irq_routing(s);
 }
 
@@ -934,11 +952,130 @@ int kvm_irqchip_commit_routes(KVMState *s)
     return kvm_vm_ioctl(s, KVM_SET_GSI_ROUTING, s->irq_routes);
 }
 
+static void kvm_irqchip_release_virq(KVMState *s, int virq)
+{
+    struct kvm_irq_routing_entry *e;
+    int i;
+
+    for (i = 0; i < s->irq_routes->nr; i++) {
+        e = &s->irq_routes->entries[i];
+        if (e->gsi == virq) {
+            s->irq_routes->nr--;
+            *e = s->irq_routes->entries[s->irq_routes->nr];
+        }
+    }
+    clear_gsi(s, virq);
+}
+
+static unsigned int kvm_hash_msi(uint32_t data)
+{
+    /* This is optimized for IA32 MSI layout. However, no other arch shall
+     * repeat the mistake of not providing a direct MSI injection API. */
+    return data & 0xff;
+}
+
+static void kvm_flush_dynamic_msi_routes(KVMState *s)
+{
+    KVMMSIRoute *route, *next;
+    unsigned int hash;
+
+    for (hash = 0; hash < KVM_MSI_HASHTAB_SIZE; hash++) {
+        QTAILQ_FOREACH_SAFE(route, &s->msi_hashtab[hash], entry, next) {
+            kvm_irqchip_release_virq(s, route->kroute.gsi);
+            QTAILQ_REMOVE(&s->msi_hashtab[hash], route, entry);
+            g_free(route);
+        }
+    }
+}
+
+static int kvm_irqchip_get_virq(KVMState *s)
+{
+    uint32_t *word = s->used_gsi_bitmap;
+    int max_words = ALIGN(s->gsi_count, 32) / 32;
+    int i, bit;
+    bool retry = true;
+
+again:
+    /* Return the lowest unused GSI in the bitmap */
+    for (i = 0; i < max_words; i++) {
+        bit = ffs(~word[i]);
+        if (!bit) {
+            continue;
+        }
+
+        return bit - 1 + i * 32;
+    }
+    if (retry) {
+        retry = false;
+        kvm_flush_dynamic_msi_routes(s);
+        goto again;
+    }
+    return -ENOSPC;
+
+}
+
+static KVMMSIRoute *kvm_lookup_msi_route(KVMState *s, MSIMessage msg)
+{
+    unsigned int hash = kvm_hash_msi(msg.data);
+    KVMMSIRoute *route;
+
+    QTAILQ_FOREACH(route, &s->msi_hashtab[hash], entry) {
+        if (route->kroute.u.msi.address_lo == (uint32_t)msg.address &&
+            route->kroute.u.msi.address_hi == (msg.address >> 32) &&
+            route->kroute.u.msi.data == msg.data) {
+            return route;
+        }
+    }
+    return NULL;
+}
+
+int kvm_irqchip_send_msi(KVMState *s, MSIMessage msg)
+{
+    KVMMSIRoute *route;
+
+    route = kvm_lookup_msi_route(s, msg);
+    if (!route) {
+        int virq, ret;
+
+        virq = kvm_irqchip_get_virq(s);
+        if (virq < 0) {
+            return virq;
+        }
+
+        route = g_malloc(sizeof(KVMMSIRoute));
+        route->kroute.gsi = virq;
+        route->kroute.type = KVM_IRQ_ROUTING_MSI;
+        route->kroute.flags = 0;
+        route->kroute.u.msi.address_lo = (uint32_t)msg.address;
+        route->kroute.u.msi.address_hi = msg.address >> 32;
+        route->kroute.u.msi.data = msg.data;
+
+        kvm_add_routing_entry(s, &route->kroute);
+
+        QTAILQ_INSERT_TAIL(&s->msi_hashtab[kvm_hash_msi(msg.data)], route,
+                           entry);
+
+        ret = kvm_irqchip_commit_routes(s);
+        if (ret < 0) {
+            return ret;
+        }
+    }
+
+    assert(route->kroute.type == KVM_IRQ_ROUTING_MSI);
+
+    return kvm_irqchip_set_irq(s, route->kroute.gsi, 1);
+}
+
 #else /* !KVM_CAP_IRQ_ROUTING */
 
 static void kvm_init_irq_routing(KVMState *s)
 {
 }
+
+int kvm_irqchip_send_msi(KVMState *s, MSIMessage msg)
+{
+    abort();
+}
 #endif /* !KVM_CAP_IRQ_ROUTING */
 
 static int kvm_irqchip_create(KVMState *s)
diff --git a/kvm.h b/kvm.h
index 4ccae8c..7857dbf 100644
--- a/kvm.h
+++ b/kvm.h
@@ -132,6 +132,7 @@ 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_irqchip_send_msi(KVMState *s, MSIMessage msg);
 
 void kvm_irqchip_add_route(KVMState *s, int gsi, int irqchip, int pin);
 int kvm_irqchip_commit_routes(KVMState *s);
-- 
1.7.3.4

[Qemu-devel] [PATCH v4 4/8] pc: Enable MSI support at APIC level

[Jan Kiszka]

Push msi_supported enabling to the APIC implementations where we can
encapsulate the decision more cleanly, hiding the details from the
generic code.

Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 hw/apic.c     |    3 +++
 hw/pc.c       |    9 ---------
 hw/xen.h      |   10 ----------
 hw/xen_apic.c |    5 +++++
 4 files changed, 8 insertions(+), 19 deletions(-)

diff --git a/hw/apic.c b/hw/apic.c
index 4eeaf88..5fbf01c 100644
--- a/hw/apic.c
+++ b/hw/apic.c
@@ -19,6 +19,7 @@
 #include "apic_internal.h"
 #include "apic.h"
 #include "ioapic.h"
+#include "msi.h"
 #include "host-utils.h"
 #include "trace.h"
 #include "pc.h"
@@ -862,6 +863,8 @@ static void apic_init(APICCommonState *s)
 
     s->timer = qemu_new_timer_ns(vm_clock, apic_timer, s);
     local_apics[s->idx] = s;
+
+    msi_supported = true;
 }
 
 static void apic_class_init(ObjectClass *klass, void *data)
diff --git a/hw/pc.c b/hw/pc.c
index 4d34a33..6691b18 100644
--- a/hw/pc.c
+++ b/hw/pc.c
@@ -911,15 +911,6 @@ static DeviceState *apic_init(void *env, uint8_t apic_id)
         apic_mapped = 1;
     }
 
-    /* KVM does not support MSI yet. */
-    if (!kvm_irqchip_in_kernel()) {
-        msi_supported = true;
-    }
-
-    if (xen_msi_support()) {
-        msi_supported = true;
-    }
-
     return dev;
 }
 
diff --git a/hw/xen.h b/hw/xen.h
index 3ae4cd0..e5926b7 100644
--- a/hw/xen.h
+++ b/hw/xen.h
@@ -57,14 +57,4 @@ void xen_register_framebuffer(struct MemoryRegion *mr);
 #  define HVM_MAX_VCPUS 32
 #endif
 
-static inline int xen_msi_support(void)
-{
-#if defined(CONFIG_XEN_CTRL_INTERFACE_VERSION) \
-    && CONFIG_XEN_CTRL_INTERFACE_VERSION >= 420
-    return xen_enabled();
-#else
-    return 0;
-#endif
-}
-
 #endif /* QEMU_HW_XEN_H */
diff --git a/hw/xen_apic.c b/hw/xen_apic.c
index 1725ff6..a9e101f 100644
--- a/hw/xen_apic.c
+++ b/hw/xen_apic.c
@@ -40,6 +40,11 @@ static void xen_apic_init(APICCommonState *s)
 {
     memory_region_init_io(&s->io_memory, &xen_apic_io_ops, s, "xen-apic-msi",
                           MSI_SPACE_SIZE);
+
+#if defined(CONFIG_XEN_CTRL_INTERFACE_VERSION) \
+    && CONFIG_XEN_CTRL_INTERFACE_VERSION >= 420
+    msi_supported = true;
+#endif
 }
 
 static void xen_apic_set_base(APICCommonState *s, uint64_t val)
-- 
1.7.3.4

[Qemu-devel] [PATCH v4 5/8] kvm: x86: Wire up MSI support for in-kernel irqchip

[Jan Kiszka]

Catch writes to the MSI MMIO region in the KVM APIC and forward them to
the kernel. Provide the kernel support GSI routing, this allows to
enable MSI support also for in-kernel irqchip mode.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 hw/kvm/apic.c |   34 ++++++++++++++++++++++++++++++++--
 1 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/hw/kvm/apic.c b/hw/kvm/apic.c
index ffe7a52..8ba4079 100644
--- a/hw/kvm/apic.c
+++ b/hw/kvm/apic.c
@@ -10,6 +10,7 @@
  * See the COPYING file in the top-level directory.
  */
 #include "hw/apic_internal.h"
+#include "hw/msi.h"
 #include "kvm.h"
 
 static inline void kvm_apic_set_reg(struct kvm_lapic_state *kapic,
@@ -145,10 +146,39 @@ static void kvm_apic_external_nmi(APICCommonState *s)
     run_on_cpu(s->cpu_env, do_inject_external_nmi, s);
 }
 
+static uint64_t kvm_apic_mem_read(void *opaque, target_phys_addr_t addr,
+                                  unsigned size)
+{
+    return ~(uint64_t)0;
+}
+
+static void kvm_apic_mem_write(void *opaque, target_phys_addr_t addr,
+                               uint64_t data, unsigned size)
+{
+    MSIMessage msg = { .address = addr, .data = data };
+    int ret;
+
+    ret = kvm_irqchip_send_msi(kvm_state, msg);
+    if (ret < 0) {
+        fprintf(stderr, "KVM: injection failed, MSI lost (%s)\n",
+                strerror(-ret));
+    }
+}
+
+static const MemoryRegionOps kvm_apic_io_ops = {
+    .read = kvm_apic_mem_read,
+    .write = kvm_apic_mem_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+};
+
 static void kvm_apic_init(APICCommonState *s)
 {
-    memory_region_init_reservation(&s->io_memory, "kvm-apic-msi",
-                                   MSI_SPACE_SIZE);
+    memory_region_init_io(&s->io_memory, &kvm_apic_io_ops, s, "kvm-apic-msi",
+                          MSI_SPACE_SIZE);
+
+    if (kvm_has_gsi_routing()) {
+        msi_supported = true;
+    }
 }
 
 static void kvm_apic_class_init(ObjectClass *klass, void *data)
-- 
1.7.3.4

[Qemu-devel] [PATCH v4 6/8] kvm: Update kernel headers

[Jan Kiszka]

Corresponding kvm.git hash: f2569053e0

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 linux-headers/linux/kvm.h |   38 ++++++++++++++++++++++++++++++++++++++
 1 files changed, 38 insertions(+), 0 deletions(-)

diff --git a/linux-headers/linux/kvm.h b/linux-headers/linux/kvm.h
index ee7bd9c..c4426ec 100644
--- a/linux-headers/linux/kvm.h
+++ b/linux-headers/linux/kvm.h
@@ -449,6 +449,30 @@ struct kvm_ppc_pvinfo {
 	__u8  pad[108];
 };
 
+/* for KVM_PPC_GET_SMMU_INFO */
+#define KVM_PPC_PAGE_SIZES_MAX_SZ	8
+
+struct kvm_ppc_one_page_size {
+	__u32 page_shift;	/* Page shift (or 0) */
+	__u32 pte_enc;		/* Encoding in the HPTE (>>12) */
+};
+
+struct kvm_ppc_one_seg_page_size {
+	__u32 page_shift;	/* Base page shift of segment (or 0) */
+	__u32 slb_enc;		/* SLB encoding for BookS */
+	struct kvm_ppc_one_page_size enc[KVM_PPC_PAGE_SIZES_MAX_SZ];
+};
+
+#define KVM_PPC_PAGE_SIZES_REAL		0x00000001
+#define KVM_PPC_1T_SEGMENTS		0x00000002
+
+struct kvm_ppc_smmu_info {
+	__u64 flags;
+	__u32 slb_size;
+	__u32 pad;
+	struct kvm_ppc_one_seg_page_size sps[KVM_PPC_PAGE_SIZES_MAX_SZ];
+};
+
 #define KVMIO 0xAE
 
 /* machine type bits, to be used as argument to KVM_CREATE_VM */
@@ -590,6 +614,8 @@ struct kvm_ppc_pvinfo {
 #define KVM_CAP_SYNC_REGS 74
 #define KVM_CAP_PCI_2_3 75
 #define KVM_CAP_KVMCLOCK_CTRL 76
+#define KVM_CAP_SIGNAL_MSI 77
+#define KVM_CAP_PPC_GET_SMMU_INFO 78
 
 #ifdef KVM_CAP_IRQ_ROUTING
 
@@ -715,6 +741,14 @@ struct kvm_one_reg {
 	__u64 addr;
 };
 
+struct kvm_msi {
+	__u32 address_lo;
+	__u32 address_hi;
+	__u32 data;
+	__u32 flags;
+	__u8  pad[16];
+};
+
 /*
  * ioctls for VM fds
  */
@@ -789,6 +823,10 @@ struct kvm_s390_ucas_mapping {
 /* Available with KVM_CAP_PCI_2_3 */
 #define KVM_ASSIGN_SET_INTX_MASK  _IOW(KVMIO,  0xa4, \
 				       struct kvm_assigned_pci_dev)
+/* Available with KVM_CAP_SIGNAL_MSI */
+#define KVM_SIGNAL_MSI            _IOW(KVMIO,  0xa5, struct kvm_msi)
+/* Available with KVM_CAP_PPC_GET_SMMU_INFO */
+#define KVM_PPC_GET_SMMU_INFO	  _IOR(KVMIO,  0xa6, struct kvm_ppc_smmu_info)
 
 /*
  * ioctls for vcpu fds
-- 
1.7.3.4

[Qemu-devel] [PATCH v4 7/8] kvm: Add support for direct MSI injections

[Jan Kiszka]

If the kernel supports KVM_SIGNAL_MSI, we can avoid the route-based
MSI injection mechanism.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 kvm-all.c |   22 +++++++++++++++++++---
 1 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/kvm-all.c b/kvm-all.c
index ff0534b..d222012 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -96,6 +96,7 @@ struct KVMState
     uint32_t *used_gsi_bitmap;
     unsigned int gsi_count;
     QTAILQ_HEAD(msi_hashtab, KVMMSIRoute) msi_hashtab[KVM_MSI_HASHTAB_SIZE];
+    bool direct_msi;
 #endif
 };
 
@@ -898,8 +899,10 @@ static void kvm_init_irq_routing(KVMState *s)
     s->irq_routes = g_malloc0(sizeof(*s->irq_routes));
     s->nr_allocated_irq_routes = 0;
 
-    for (i = 0; i < KVM_MSI_HASHTAB_SIZE; i++) {
-        QTAILQ_INIT(&s->msi_hashtab[i]);
+    if (!s->direct_msi) {
+        for (i = 0; i < KVM_MSI_HASHTAB_SIZE; i++) {
+            QTAILQ_INIT(&s->msi_hashtab[i]);
+        }
     }
 
     kvm_arch_init_irq_routing(s);
@@ -1005,7 +1008,7 @@ again:
 
         return bit - 1 + i * 32;
     }
-    if (retry) {
+    if (!s->direct_msi && retry) {
         retry = false;
         kvm_flush_dynamic_msi_routes(s);
         goto again;
@@ -1031,8 +1034,19 @@ static KVMMSIRoute *kvm_lookup_msi_route(KVMState *s, MSIMessage msg)
 
 int kvm_irqchip_send_msi(KVMState *s, MSIMessage msg)
 {
+    struct kvm_msi msi;
     KVMMSIRoute *route;
 
+    if (s->direct_msi) {
+        msi.address_lo = (uint32_t)msg.address;
+        msi.address_hi = msg.address >> 32;
+        msi.data = msg.data;
+        msi.flags = 0;
+        memset(msi.pad, 0, sizeof(msi.pad));
+
+        return kvm_vm_ioctl(s, KVM_SIGNAL_MSI, &msi);
+    }
+
     route = kvm_lookup_msi_route(s, msg);
     if (!route) {
         int virq, ret;
@@ -1209,6 +1223,8 @@ int kvm_init(void)
     s->pit_state2 = kvm_check_extension(s, KVM_CAP_PIT_STATE2);
 #endif
 
+    s->direct_msi = (kvm_check_extension(s, KVM_CAP_SIGNAL_MSI) > 0);
+
     ret = kvm_arch_init(s);
     if (ret < 0) {
         goto err;
-- 
1.7.3.4

[Qemu-devel] [PATCH v4 8/8] kvm: Enable in-kernel irqchip support by default

[Jan Kiszka]

As MSI is now fully supported by KVM (/wrt available features in
upstream), we can finally enable the in-kernel irqchip by default.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 kvm-all.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/kvm-all.c b/kvm-all.c
index d222012..1913d6a 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -1099,7 +1099,7 @@ static int kvm_irqchip_create(KVMState *s)
 
     if (QTAILQ_EMPTY(&list->head) ||
         !qemu_opt_get_bool(QTAILQ_FIRST(&list->head),
-                           "kernel_irqchip", false) ||
+                           "kernel_irqchip", true) ||
         !kvm_check_extension(s, KVM_CAP_IRQCHIP)) {
         return 0;
     }
-- 
1.7.3.4