[Qemu-devel] [PATCH 10/17] s390x: keep hint on virtio managing size

[Alexander Graf]

The s390x virtio bus keeps management information on virtio after the top
of the guest's RAM. We need to be able to tell the guest the size of its
RAM (without virtio stuff), but also be able to trap when the guest accesses
RAM outside of its scope (including virtio stuff).

So we need a variable telling us the size of the virtio stuff, so we can
calculate the highest available RAM address from that.

While at it, also increase the maximum number of virtio pages, so we play
along well with more recent kernels that spawn a ridiculous number of virtio
console adapters.

Signed-off-by: Alexander Graf <address@hidden>
---
 hw/s390-virtio-bus.c |    3 +++
 hw/s390-virtio-bus.h |    2 +-
 target-s390x/cpu.h   |    3 +++
 3 files changed, 7 insertions(+), 1 deletions(-)

diff --git a/hw/s390-virtio-bus.c b/hw/s390-virtio-bus.c
index bb49e39..a90963b 100644
--- a/hw/s390-virtio-bus.c
+++ b/hw/s390-virtio-bus.c
@@ -60,6 +60,9 @@ static const VirtIOBindings virtio_s390_bindings;
 
 static ram_addr_t s390_virtio_device_num_vq(VirtIOS390Device *dev);
 
+/* length of VirtIO device pages */
+target_phys_addr_t virtio_size = S390_DEVICE_PAGES * TARGET_PAGE_SIZE;
+
 VirtIOS390Bus *s390_virtio_bus_init(ram_addr_t *ram_size)
 {
     VirtIOS390Bus *bus;
diff --git a/hw/s390-virtio-bus.h b/hw/s390-virtio-bus.h
index edf6d04..0c412d0 100644
--- a/hw/s390-virtio-bus.h
+++ b/hw/s390-virtio-bus.h
@@ -33,7 +33,7 @@
 #define VIRTIO_VQCONFIG_LEN            24
 
 #define VIRTIO_RING_LEN                        (TARGET_PAGE_SIZE * 3)
-#define S390_DEVICE_PAGES              256
+#define S390_DEVICE_PAGES              512
 
 typedef struct VirtIOS390Device {
     DeviceState qdev;
diff --git a/target-s390x/cpu.h b/target-s390x/cpu.h
index a84b3ee..6ba303d 100644
--- a/target-s390x/cpu.h
+++ b/target-s390x/cpu.h
@@ -293,6 +293,9 @@ void kvm_s390_interrupt_internal(CPUState *env, int type, 
uint32_t parm,
                                  uint64_t parm64, int vm);
 CPUState *s390_cpu_addr2state(uint16_t cpu_addr);
 
+/* from s390-virtio-bus */
+extern target_phys_addr_t virtio_size;
+
 #ifndef KVM_S390_SIGP_STOP
 #define KVM_S390_SIGP_STOP              0
 #define KVM_S390_PROGRAM_INT            0
-- 
1.6.0.2