* [PATCH v5 1/6] virtio_ccw: pass a cookie value to kvm hypercall
2013-02-28 11:33 [PATCH v5 0/6] kvm: Make ioeventfd usable on s390 Cornelia Huck
@ 2013-02-28 11:33 ` Cornelia Huck
2013-02-28 11:33 ` [PATCH v5 2/6] KVM: s390: Export virtio-ccw api Cornelia Huck
` (6 subsequent siblings)
7 siblings, 0 replies; 13+ messages in thread
From: Cornelia Huck @ 2013-02-28 11:33 UTC (permalink / raw)
To: Marcelo Tosatti, Gleb Natapov
Cc: Christian Borntraeger, Carsten Otte, Alexander Graf,
Heiko Carstens, Martin Schwidefsky, Michael S. Tsirkin, KVM,
linux-s390, qemu-devel
From: "Michael S. Tsirkin" <mst@redhat.com>
Lookups by channel/vq pair on host during virtio notifications might be
expensive. Interpret hypercall return value as a cookie which host can
use to do device lookups for the next notification more efficiently.
[CH: Fix line > 80 chars]
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
---
drivers/s390/kvm/virtio_ccw.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/drivers/s390/kvm/virtio_ccw.c b/drivers/s390/kvm/virtio_ccw.c
index 3217dfe..259a2fb 100644
--- a/drivers/s390/kvm/virtio_ccw.c
+++ b/drivers/s390/kvm/virtio_ccw.c
@@ -77,6 +77,7 @@ struct virtio_ccw_vq_info {
void *queue;
struct vq_info_block *info_block;
struct list_head node;
+ long cookie;
};
#define KVM_VIRTIO_CCW_RING_ALIGN 4096
@@ -145,15 +146,18 @@ static int ccw_io_helper(struct virtio_ccw_device *vcdev,
}
static inline long do_kvm_notify(struct subchannel_id schid,
- unsigned long queue_index)
+ unsigned long queue_index,
+ long cookie)
{
register unsigned long __nr asm("1") = KVM_S390_VIRTIO_CCW_NOTIFY;
register struct subchannel_id __schid asm("2") = schid;
register unsigned long __index asm("3") = queue_index;
register long __rc asm("2");
+ register long __cookie asm("4") = cookie;
asm volatile ("diag 2,4,0x500\n"
- : "=d" (__rc) : "d" (__nr), "d" (__schid), "d" (__index)
+ : "=d" (__rc) : "d" (__nr), "d" (__schid), "d" (__index),
+ "d"(__cookie)
: "memory", "cc");
return __rc;
}
@@ -166,7 +170,8 @@ static void virtio_ccw_kvm_notify(struct virtqueue *vq)
vcdev = to_vc_device(info->vq->vdev);
ccw_device_get_schid(vcdev->cdev, &schid);
- do_kvm_notify(schid, virtqueue_get_queue_index(vq));
+ info->cookie = do_kvm_notify(schid, virtqueue_get_queue_index(vq),
+ info->cookie);
}
static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,
--
1.7.12.4
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH v5 2/6] KVM: s390: Export virtio-ccw api.
2013-02-28 11:33 [PATCH v5 0/6] kvm: Make ioeventfd usable on s390 Cornelia Huck
2013-02-28 11:33 ` [PATCH v5 1/6] virtio_ccw: pass a cookie value to kvm hypercall Cornelia Huck
@ 2013-02-28 11:33 ` Cornelia Huck
2013-02-28 11:33 ` [PATCH v5 3/6] KVM: Initialize irqfd from kvm_init() Cornelia Huck
` (5 subsequent siblings)
7 siblings, 0 replies; 13+ messages in thread
From: Cornelia Huck @ 2013-02-28 11:33 UTC (permalink / raw)
To: Marcelo Tosatti, Gleb Natapov
Cc: Christian Borntraeger, Carsten Otte, Alexander Graf,
Heiko Carstens, Martin Schwidefsky, Michael S. Tsirkin, KVM,
linux-s390, qemu-devel
Export the virtio-ccw api in a header for usage by other code.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
---
arch/s390/include/uapi/asm/Kbuild | 1 +
arch/s390/include/uapi/asm/virtio-ccw.h | 21 +++++++++++++++++++++
drivers/s390/kvm/virtio_ccw.c | 5 +----
3 files changed, 23 insertions(+), 4 deletions(-)
create mode 100644 arch/s390/include/uapi/asm/virtio-ccw.h
diff --git a/arch/s390/include/uapi/asm/Kbuild b/arch/s390/include/uapi/asm/Kbuild
index 7bf68ff..9ccd190 100644
--- a/arch/s390/include/uapi/asm/Kbuild
+++ b/arch/s390/include/uapi/asm/Kbuild
@@ -44,5 +44,6 @@ header-y += termios.h
header-y += types.h
header-y += ucontext.h
header-y += unistd.h
+header-y += virtio-ccw.h
header-y += vtoc.h
header-y += zcrypt.h
diff --git a/arch/s390/include/uapi/asm/virtio-ccw.h b/arch/s390/include/uapi/asm/virtio-ccw.h
new file mode 100644
index 0000000..a9a4ebf
--- /dev/null
+++ b/arch/s390/include/uapi/asm/virtio-ccw.h
@@ -0,0 +1,21 @@
+/*
+ * Definitions for virtio-ccw devices.
+ *
+ * Copyright IBM Corp. 2013
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License (version 2 only)
+ * as published by the Free Software Foundation.
+ *
+ * Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
+ */
+#ifndef __KVM_VIRTIO_CCW_H
+#define __KVM_VIRTIO_CCW_H
+
+/* Alignment of vring buffers. */
+#define KVM_VIRTIO_CCW_RING_ALIGN 4096
+
+/* Subcode for diagnose 500 (virtio hypercall). */
+#define KVM_S390_VIRTIO_CCW_NOTIFY 3
+
+#endif
diff --git a/drivers/s390/kvm/virtio_ccw.c b/drivers/s390/kvm/virtio_ccw.c
index 259a2fb..bf5ba3b 100644
--- a/drivers/s390/kvm/virtio_ccw.c
+++ b/drivers/s390/kvm/virtio_ccw.c
@@ -31,6 +31,7 @@
#include <asm/irq.h>
#include <asm/cio.h>
#include <asm/ccwdev.h>
+#include <asm/virtio-ccw.h>
/*
* virtio related functions
@@ -80,10 +81,6 @@ struct virtio_ccw_vq_info {
long cookie;
};
-#define KVM_VIRTIO_CCW_RING_ALIGN 4096
-
-#define KVM_S390_VIRTIO_CCW_NOTIFY 3
-
#define CCW_CMD_SET_VQ 0x13
#define CCW_CMD_VDEV_RESET 0x33
#define CCW_CMD_SET_IND 0x43
--
1.7.12.4
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH v5 3/6] KVM: Initialize irqfd from kvm_init().
2013-02-28 11:33 [PATCH v5 0/6] kvm: Make ioeventfd usable on s390 Cornelia Huck
2013-02-28 11:33 ` [PATCH v5 1/6] virtio_ccw: pass a cookie value to kvm hypercall Cornelia Huck
2013-02-28 11:33 ` [PATCH v5 2/6] KVM: s390: Export virtio-ccw api Cornelia Huck
@ 2013-02-28 11:33 ` Cornelia Huck
2013-02-28 11:33 ` [PATCH v5 4/6] KVM: Introduce KVM_VIRTIO_CCW_NOTIFY_BUS Cornelia Huck
` (4 subsequent siblings)
7 siblings, 0 replies; 13+ messages in thread
From: Cornelia Huck @ 2013-02-28 11:33 UTC (permalink / raw)
To: Marcelo Tosatti, Gleb Natapov
Cc: Christian Borntraeger, Carsten Otte, Alexander Graf,
Heiko Carstens, Martin Schwidefsky, Michael S. Tsirkin, KVM,
linux-s390, qemu-devel
Currently, eventfd introduces module_init/module_exit functions
to initialize/cleanup the irqfd workqueue. This only works, however,
if no other module_init/module_exit functions are built into the
same module.
Let's just move the initialization and cleanup to kvm_init and kvm_exit.
This way, it is also clearer where kvm startup may fail.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
---
include/linux/kvm_host.h | 13 +++++++++++++
virt/kvm/eventfd.c | 7 ++-----
virt/kvm/kvm_main.c | 6 ++++++
3 files changed, 21 insertions(+), 5 deletions(-)
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 722cae7..3b768ef 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -423,6 +423,19 @@ void kvm_vcpu_uninit(struct kvm_vcpu *vcpu);
int __must_check vcpu_load(struct kvm_vcpu *vcpu);
void vcpu_put(struct kvm_vcpu *vcpu);
+#ifdef __KVM_HAVE_IOAPIC
+int kvm_irqfd_init(void);
+void kvm_irqfd_exit(void);
+#else
+static inline int kvm_irqfd_init(void)
+{
+ return 0;
+}
+
+static inline void kvm_irqfd_exit(void)
+{
+}
+#endif
int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
struct module *module);
void kvm_exit(void);
diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
index b6eea5c..f0ced1a 100644
--- a/virt/kvm/eventfd.c
+++ b/virt/kvm/eventfd.c
@@ -544,7 +544,7 @@ void kvm_irq_routing_update(struct kvm *kvm,
* aggregated from all vm* instances. We need our own isolated single-thread
* queue to prevent deadlock against flushing the normal work-queue.
*/
-static int __init irqfd_module_init(void)
+int kvm_irqfd_init(void)
{
irqfd_cleanup_wq = create_singlethread_workqueue("kvm-irqfd-cleanup");
if (!irqfd_cleanup_wq)
@@ -553,13 +553,10 @@ static int __init irqfd_module_init(void)
return 0;
}
-static void __exit irqfd_module_exit(void)
+void kvm_irqfd_exit(void)
{
destroy_workqueue(irqfd_cleanup_wq);
}
-
-module_init(irqfd_module_init);
-module_exit(irqfd_module_exit);
#endif
/*
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index adc68fe..7c188a3 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2920,6 +2920,9 @@ int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
int r;
int cpu;
+ r = kvm_irqfd_init();
+ if (r)
+ goto out_irqfd;
r = kvm_arch_init(opaque);
if (r)
goto out_fail;
@@ -3000,6 +3003,8 @@ out_free_0a:
out_free_0:
kvm_arch_exit();
out_fail:
+ kvm_irqfd_exit();
+out_irqfd:
return r;
}
EXPORT_SYMBOL_GPL(kvm_init);
@@ -3016,6 +3021,7 @@ void kvm_exit(void)
on_each_cpu(hardware_disable_nolock, NULL, 1);
kvm_arch_hardware_unsetup();
kvm_arch_exit();
+ kvm_irqfd_exit();
free_cpumask_var(cpus_hardware_enabled);
}
EXPORT_SYMBOL_GPL(kvm_exit);
--
1.7.12.4
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH v5 4/6] KVM: Introduce KVM_VIRTIO_CCW_NOTIFY_BUS.
2013-02-28 11:33 [PATCH v5 0/6] kvm: Make ioeventfd usable on s390 Cornelia Huck
` (2 preceding siblings ...)
2013-02-28 11:33 ` [PATCH v5 3/6] KVM: Initialize irqfd from kvm_init() Cornelia Huck
@ 2013-02-28 11:33 ` Cornelia Huck
2013-02-28 11:33 ` [PATCH v5 5/6] KVM: ioeventfd for virtio-ccw devices Cornelia Huck
` (3 subsequent siblings)
7 siblings, 0 replies; 13+ messages in thread
From: Cornelia Huck @ 2013-02-28 11:33 UTC (permalink / raw)
To: Marcelo Tosatti, Gleb Natapov
Cc: Christian Borntraeger, Carsten Otte, Alexander Graf,
Heiko Carstens, Martin Schwidefsky, Michael S. Tsirkin, KVM,
linux-s390, qemu-devel
Add a new bus type for virtio-ccw devices on s390.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
---
include/linux/kvm_host.h | 1 +
1 file changed, 1 insertion(+)
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 3b768ef..206247f 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -148,6 +148,7 @@ struct kvm_io_bus {
enum kvm_bus {
KVM_MMIO_BUS,
KVM_PIO_BUS,
+ KVM_VIRTIO_CCW_NOTIFY_BUS,
KVM_NR_BUSES
};
--
1.7.12.4
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH v5 5/6] KVM: ioeventfd for virtio-ccw devices.
2013-02-28 11:33 [PATCH v5 0/6] kvm: Make ioeventfd usable on s390 Cornelia Huck
` (3 preceding siblings ...)
2013-02-28 11:33 ` [PATCH v5 4/6] KVM: Introduce KVM_VIRTIO_CCW_NOTIFY_BUS Cornelia Huck
@ 2013-02-28 11:33 ` Cornelia Huck
2013-02-28 11:33 ` [PATCH v5 6/6] KVM: s390: Wire up ioeventfd Cornelia Huck
` (2 subsequent siblings)
7 siblings, 0 replies; 13+ messages in thread
From: Cornelia Huck @ 2013-02-28 11:33 UTC (permalink / raw)
To: Marcelo Tosatti, Gleb Natapov
Cc: Christian Borntraeger, Carsten Otte, Alexander Graf,
Heiko Carstens, Martin Schwidefsky, Michael S. Tsirkin, KVM,
linux-s390, qemu-devel
Enhance KVM_IOEVENTFD with a new flag that allows to attach to virtio-ccw
devices on s390 via the KVM_VIRTIO_CCW_NOTIFY_BUS.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
---
Documentation/virtual/kvm/api.txt | 8 ++++++++
include/uapi/linux/kvm.h | 3 +++
virt/kvm/eventfd.c | 17 +++++++++++++----
3 files changed, 24 insertions(+), 4 deletions(-)
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index c2534c3..86232d6 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -1468,15 +1468,23 @@ struct kvm_ioeventfd {
__u8 pad[36];
};
+For the special case of virtio-ccw devices on s390, the ioevent is matched
+to a subchannel/virtqueue tuple instead.
+
The following flags are defined:
#define KVM_IOEVENTFD_FLAG_DATAMATCH (1 << kvm_ioeventfd_flag_nr_datamatch)
#define KVM_IOEVENTFD_FLAG_PIO (1 << kvm_ioeventfd_flag_nr_pio)
#define KVM_IOEVENTFD_FLAG_DEASSIGN (1 << kvm_ioeventfd_flag_nr_deassign)
+#define KVM_IOEVENTFD_FLAG_VIRTIO_CCW_NOTIFY \
+ (1 << kvm_ioeventfd_flag_nr_virtio_ccw_notify)
If datamatch flag is set, the event will be signaled only if the written value
to the registered address is equal to datamatch in struct kvm_ioeventfd.
+For virtio-ccw devices, addr contains the subchannel id and datamatch the
+virtqueue index.
+
4.60 KVM_DIRTY_TLB
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 9a2db57..8f3e5ae 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -448,12 +448,15 @@ enum {
kvm_ioeventfd_flag_nr_datamatch,
kvm_ioeventfd_flag_nr_pio,
kvm_ioeventfd_flag_nr_deassign,
+ kvm_ioeventfd_flag_nr_virtio_ccw_notify,
kvm_ioeventfd_flag_nr_max,
};
#define KVM_IOEVENTFD_FLAG_DATAMATCH (1 << kvm_ioeventfd_flag_nr_datamatch)
#define KVM_IOEVENTFD_FLAG_PIO (1 << kvm_ioeventfd_flag_nr_pio)
#define KVM_IOEVENTFD_FLAG_DEASSIGN (1 << kvm_ioeventfd_flag_nr_deassign)
+#define KVM_IOEVENTFD_FLAG_VIRTIO_CCW_NOTIFY \
+ (1 << kvm_ioeventfd_flag_nr_virtio_ccw_notify)
#define KVM_IOEVENTFD_VALID_FLAG_MASK ((1 << kvm_ioeventfd_flag_nr_max) - 1)
diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
index f0ced1a..c9b6494 100644
--- a/virt/kvm/eventfd.c
+++ b/virt/kvm/eventfd.c
@@ -675,15 +675,24 @@ ioeventfd_check_collision(struct kvm *kvm, struct _ioeventfd *p)
return false;
}
+static enum kvm_bus ioeventfd_bus_from_flags(__u32 flags)
+{
+ if (flags & KVM_IOEVENTFD_FLAG_PIO)
+ return KVM_PIO_BUS;
+ if (flags & KVM_IOEVENTFD_FLAG_VIRTIO_CCW_NOTIFY)
+ return KVM_VIRTIO_CCW_NOTIFY_BUS;
+ return KVM_MMIO_BUS;
+}
+
static int
kvm_assign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
{
- int pio = args->flags & KVM_IOEVENTFD_FLAG_PIO;
- enum kvm_bus bus_idx = pio ? KVM_PIO_BUS : KVM_MMIO_BUS;
+ enum kvm_bus bus_idx;
struct _ioeventfd *p;
struct eventfd_ctx *eventfd;
int ret;
+ bus_idx = ioeventfd_bus_from_flags(args->flags);
/* must be natural-word sized */
switch (args->len) {
case 1:
@@ -758,12 +767,12 @@ fail:
static int
kvm_deassign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
{
- int pio = args->flags & KVM_IOEVENTFD_FLAG_PIO;
- enum kvm_bus bus_idx = pio ? KVM_PIO_BUS : KVM_MMIO_BUS;
+ enum kvm_bus bus_idx;
struct _ioeventfd *p, *tmp;
struct eventfd_ctx *eventfd;
int ret = -ENOENT;
+ bus_idx = ioeventfd_bus_from_flags(args->flags);
eventfd = eventfd_ctx_fdget(args->fd);
if (IS_ERR(eventfd))
return PTR_ERR(eventfd);
--
1.7.12.4
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH v5 6/6] KVM: s390: Wire up ioeventfd.
2013-02-28 11:33 [PATCH v5 0/6] kvm: Make ioeventfd usable on s390 Cornelia Huck
` (4 preceding siblings ...)
2013-02-28 11:33 ` [PATCH v5 5/6] KVM: ioeventfd for virtio-ccw devices Cornelia Huck
@ 2013-02-28 11:33 ` Cornelia Huck
2013-03-05 0:07 ` Marcelo Tosatti
2013-02-28 13:12 ` [PATCH v5 0/6] kvm: Make ioeventfd usable on s390 Michael S. Tsirkin
2013-03-05 22:14 ` Marcelo Tosatti
7 siblings, 1 reply; 13+ messages in thread
From: Cornelia Huck @ 2013-02-28 11:33 UTC (permalink / raw)
To: Marcelo Tosatti, Gleb Natapov
Cc: Carsten Otte, KVM, Michael S. Tsirkin, linux-s390, Heiko Carstens,
Alexander Graf, qemu-devel, Christian Borntraeger,
Martin Schwidefsky
Enable ioeventfd support on s390 and hook up diagnose 500 virtio-ccw
notifications.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
---
arch/s390/kvm/Kconfig | 1 +
arch/s390/kvm/Makefile | 2 +-
arch/s390/kvm/diag.c | 26 ++++++++++++++++++++++++++
arch/s390/kvm/kvm-s390.c | 1 +
4 files changed, 29 insertions(+), 1 deletion(-)
diff --git a/arch/s390/kvm/Kconfig b/arch/s390/kvm/Kconfig
index b58dd86..3c43e30 100644
--- a/arch/s390/kvm/Kconfig
+++ b/arch/s390/kvm/Kconfig
@@ -22,6 +22,7 @@ config KVM
select PREEMPT_NOTIFIERS
select ANON_INODES
select HAVE_KVM_CPU_RELAX_INTERCEPT
+ select HAVE_KVM_EVENTFD
---help---
Support hosting paravirtualized guest machines using the SIE
virtualization capability on the mainframe. This should work
diff --git a/arch/s390/kvm/Makefile b/arch/s390/kvm/Makefile
index 3975722..8fe9d65 100644
--- a/arch/s390/kvm/Makefile
+++ b/arch/s390/kvm/Makefile
@@ -6,7 +6,7 @@
# it under the terms of the GNU General Public License (version 2 only)
# as published by the Free Software Foundation.
-common-objs = $(addprefix ../../../virt/kvm/, kvm_main.o)
+common-objs = $(addprefix ../../../virt/kvm/, kvm_main.o eventfd.o)
ccflags-y := -Ivirt/kvm -Iarch/s390/kvm
diff --git a/arch/s390/kvm/diag.c b/arch/s390/kvm/diag.c
index a390687..1c01a99 100644
--- a/arch/s390/kvm/diag.c
+++ b/arch/s390/kvm/diag.c
@@ -13,6 +13,7 @@
#include <linux/kvm.h>
#include <linux/kvm_host.h>
+#include <asm/virtio-ccw.h>
#include "kvm-s390.h"
#include "trace.h"
#include "trace-s390.h"
@@ -104,6 +105,29 @@ static int __diag_ipl_functions(struct kvm_vcpu *vcpu)
return -EREMOTE;
}
+static int __diag_virtio_hypercall(struct kvm_vcpu *vcpu)
+{
+ int ret, idx;
+
+ /* No virtio-ccw notification? Get out quickly. */
+ if (!vcpu->kvm->arch.css_support ||
+ (vcpu->run->s.regs.gprs[1] != KVM_S390_VIRTIO_CCW_NOTIFY))
+ return -EOPNOTSUPP;
+
+ idx = srcu_read_lock(&vcpu->kvm->srcu);
+ /*
+ * The layout is as follows:
+ * - gpr 2 contains the subchannel id (passed as addr)
+ * - gpr 3 contains the virtqueue index (passed as datamatch)
+ */
+ ret = kvm_io_bus_write(vcpu->kvm, KVM_VIRTIO_CCW_NOTIFY_BUS,
+ vcpu->run->s.regs.gprs[2],
+ 8, &vcpu->run->s.regs.gprs[3]);
+ srcu_read_unlock(&vcpu->kvm->srcu, idx);
+ /* kvm_io_bus_write returns -EOPNOTSUPP if it found no match. */
+ return ret < 0 ? ret : 0;
+}
+
int kvm_s390_handle_diag(struct kvm_vcpu *vcpu)
{
int code = (vcpu->arch.sie_block->ipb & 0xfff0000) >> 16;
@@ -118,6 +142,8 @@ int kvm_s390_handle_diag(struct kvm_vcpu *vcpu)
return __diag_time_slice_end_directed(vcpu);
case 0x308:
return __diag_ipl_functions(vcpu);
+ case 0x500:
+ return __diag_virtio_hypercall(vcpu);
default:
return -EOPNOTSUPP;
}
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 4377d18..c7671e5 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -142,6 +142,7 @@ int kvm_dev_ioctl_check_extension(long ext)
case KVM_CAP_ONE_REG:
case KVM_CAP_ENABLE_CAP:
case KVM_CAP_S390_CSS_SUPPORT:
+ case KVM_CAP_IOEVENTFD:
r = 1;
break;
case KVM_CAP_NR_VCPUS:
--
1.7.12.4
^ permalink raw reply related [flat|nested] 13+ messages in thread* Re: [PATCH v5 6/6] KVM: s390: Wire up ioeventfd.
2013-02-28 11:33 ` [PATCH v5 6/6] KVM: s390: Wire up ioeventfd Cornelia Huck
@ 2013-03-05 0:07 ` Marcelo Tosatti
2013-03-05 8:13 ` Cornelia Huck
0 siblings, 1 reply; 13+ messages in thread
From: Marcelo Tosatti @ 2013-03-05 0:07 UTC (permalink / raw)
To: Cornelia Huck
Cc: Carsten Otte, KVM, Gleb Natapov, Michael S. Tsirkin, linux-s390,
Heiko Carstens, Alexander Graf, qemu-devel, Christian Borntraeger,
Martin Schwidefsky
On Thu, Feb 28, 2013 at 12:33:21PM +0100, Cornelia Huck wrote:
> Enable ioeventfd support on s390 and hook up diagnose 500 virtio-ccw
> notifications.
>
> Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
> ---
> arch/s390/kvm/Kconfig | 1 +
> arch/s390/kvm/Makefile | 2 +-
> arch/s390/kvm/diag.c | 26 ++++++++++++++++++++++++++
> arch/s390/kvm/kvm-s390.c | 1 +
> 4 files changed, 29 insertions(+), 1 deletion(-)
>
> diff --git a/arch/s390/kvm/Kconfig b/arch/s390/kvm/Kconfig
> index b58dd86..3c43e30 100644
> --- a/arch/s390/kvm/Kconfig
> +++ b/arch/s390/kvm/Kconfig
> @@ -22,6 +22,7 @@ config KVM
> select PREEMPT_NOTIFIERS
> select ANON_INODES
> select HAVE_KVM_CPU_RELAX_INTERCEPT
> + select HAVE_KVM_EVENTFD
> ---help---
> Support hosting paravirtualized guest machines using the SIE
> virtualization capability on the mainframe. This should work
> diff --git a/arch/s390/kvm/Makefile b/arch/s390/kvm/Makefile
> index 3975722..8fe9d65 100644
> --- a/arch/s390/kvm/Makefile
> +++ b/arch/s390/kvm/Makefile
> @@ -6,7 +6,7 @@
> # it under the terms of the GNU General Public License (version 2 only)
> # as published by the Free Software Foundation.
>
> -common-objs = $(addprefix ../../../virt/kvm/, kvm_main.o)
> +common-objs = $(addprefix ../../../virt/kvm/, kvm_main.o eventfd.o)
>
> ccflags-y := -Ivirt/kvm -Iarch/s390/kvm
>
> diff --git a/arch/s390/kvm/diag.c b/arch/s390/kvm/diag.c
> index a390687..1c01a99 100644
> --- a/arch/s390/kvm/diag.c
> +++ b/arch/s390/kvm/diag.c
> @@ -13,6 +13,7 @@
>
> #include <linux/kvm.h>
> #include <linux/kvm_host.h>
> +#include <asm/virtio-ccw.h>
> #include "kvm-s390.h"
> #include "trace.h"
> #include "trace-s390.h"
> @@ -104,6 +105,29 @@ static int __diag_ipl_functions(struct kvm_vcpu *vcpu)
> return -EREMOTE;
> }
>
> +static int __diag_virtio_hypercall(struct kvm_vcpu *vcpu)
> +{
> + int ret, idx;
> +
> + /* No virtio-ccw notification? Get out quickly. */
> + if (!vcpu->kvm->arch.css_support ||
> + (vcpu->run->s.regs.gprs[1] != KVM_S390_VIRTIO_CCW_NOTIFY))
> + return -EOPNOTSUPP;
> +
> + idx = srcu_read_lock(&vcpu->kvm->srcu);
> + /*
> + * The layout is as follows:
> + * - gpr 2 contains the subchannel id (passed as addr)
> + * - gpr 3 contains the virtqueue index (passed as datamatch)
> + */
> + ret = kvm_io_bus_write(vcpu->kvm, KVM_VIRTIO_CCW_NOTIFY_BUS,
> + vcpu->run->s.regs.gprs[2],
> + 8, &vcpu->run->s.regs.gprs[3]);
> + srcu_read_unlock(&vcpu->kvm->srcu, idx);
> + /* kvm_io_bus_write returns -EOPNOTSUPP if it found no match. */
> + return ret < 0 ? ret : 0;
> +}
> +
What about the cookie?
^ permalink raw reply [flat|nested] 13+ messages in thread* Re: [PATCH v5 6/6] KVM: s390: Wire up ioeventfd.
2013-03-05 0:07 ` Marcelo Tosatti
@ 2013-03-05 8:13 ` Cornelia Huck
2013-03-05 13:19 ` Michael S. Tsirkin
0 siblings, 1 reply; 13+ messages in thread
From: Cornelia Huck @ 2013-03-05 8:13 UTC (permalink / raw)
To: Marcelo Tosatti
Cc: Gleb Natapov, Christian Borntraeger, Carsten Otte, Alexander Graf,
Heiko Carstens, Martin Schwidefsky, Michael S. Tsirkin, KVM,
linux-s390, qemu-devel
On Mon, 4 Mar 2013 21:07:41 -0300
Marcelo Tosatti <mtosatti@redhat.com> wrote:
> On Thu, Feb 28, 2013 at 12:33:21PM +0100, Cornelia Huck wrote:
> > Enable ioeventfd support on s390 and hook up diagnose 500 virtio-ccw
> > notifications.
> >
> > Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
> > ---
> > arch/s390/kvm/Kconfig | 1 +
> > arch/s390/kvm/Makefile | 2 +-
> > arch/s390/kvm/diag.c | 26 ++++++++++++++++++++++++++
> > arch/s390/kvm/kvm-s390.c | 1 +
> > 4 files changed, 29 insertions(+), 1 deletion(-)
> >
> > diff --git a/arch/s390/kvm/Kconfig b/arch/s390/kvm/Kconfig
> > index b58dd86..3c43e30 100644
> > --- a/arch/s390/kvm/Kconfig
> > +++ b/arch/s390/kvm/Kconfig
> > @@ -22,6 +22,7 @@ config KVM
> > select PREEMPT_NOTIFIERS
> > select ANON_INODES
> > select HAVE_KVM_CPU_RELAX_INTERCEPT
> > + select HAVE_KVM_EVENTFD
> > ---help---
> > Support hosting paravirtualized guest machines using the SIE
> > virtualization capability on the mainframe. This should work
> > diff --git a/arch/s390/kvm/Makefile b/arch/s390/kvm/Makefile
> > index 3975722..8fe9d65 100644
> > --- a/arch/s390/kvm/Makefile
> > +++ b/arch/s390/kvm/Makefile
> > @@ -6,7 +6,7 @@
> > # it under the terms of the GNU General Public License (version 2 only)
> > # as published by the Free Software Foundation.
> >
> > -common-objs = $(addprefix ../../../virt/kvm/, kvm_main.o)
> > +common-objs = $(addprefix ../../../virt/kvm/, kvm_main.o eventfd.o)
> >
> > ccflags-y := -Ivirt/kvm -Iarch/s390/kvm
> >
> > diff --git a/arch/s390/kvm/diag.c b/arch/s390/kvm/diag.c
> > index a390687..1c01a99 100644
> > --- a/arch/s390/kvm/diag.c
> > +++ b/arch/s390/kvm/diag.c
> > @@ -13,6 +13,7 @@
> >
> > #include <linux/kvm.h>
> > #include <linux/kvm_host.h>
> > +#include <asm/virtio-ccw.h>
> > #include "kvm-s390.h"
> > #include "trace.h"
> > #include "trace-s390.h"
> > @@ -104,6 +105,29 @@ static int __diag_ipl_functions(struct kvm_vcpu *vcpu)
> > return -EREMOTE;
> > }
> >
> > +static int __diag_virtio_hypercall(struct kvm_vcpu *vcpu)
> > +{
> > + int ret, idx;
> > +
> > + /* No virtio-ccw notification? Get out quickly. */
> > + if (!vcpu->kvm->arch.css_support ||
> > + (vcpu->run->s.regs.gprs[1] != KVM_S390_VIRTIO_CCW_NOTIFY))
> > + return -EOPNOTSUPP;
> > +
> > + idx = srcu_read_lock(&vcpu->kvm->srcu);
> > + /*
> > + * The layout is as follows:
> > + * - gpr 2 contains the subchannel id (passed as addr)
> > + * - gpr 3 contains the virtqueue index (passed as datamatch)
> > + */
> > + ret = kvm_io_bus_write(vcpu->kvm, KVM_VIRTIO_CCW_NOTIFY_BUS,
> > + vcpu->run->s.regs.gprs[2],
> > + 8, &vcpu->run->s.regs.gprs[3]);
> > + srcu_read_unlock(&vcpu->kvm->srcu, idx);
> > + /* kvm_io_bus_write returns -EOPNOTSUPP if it found no match. */
> > + return ret < 0 ? ret : 0;
> > +}
> > +
>
> What about the cookie?
This is the not-performance-optimized version which went through our
testing and which I'd like to see applied. I also have a not-yet-tested
patch that adds cookie support (see below), but I'd like to postpone
this to 3.10.
commit 8fce4a8a3478252f7ee2eb74d2732673f5911120
Author: Cornelia Huck <cornelia.huck@de.ibm.com>
Date: Tue Feb 26 17:05:01 2013 +0100
virtio-ccw: ioeventfd: use cookies
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
diff --git a/arch/s390/kvm/diag.c b/arch/s390/kvm/diag.c
index 1c01a99..bd2a013 100644
--- a/arch/s390/kvm/diag.c
+++ b/arch/s390/kvm/diag.c
@@ -108,22 +108,29 @@ static int __diag_ipl_functions(struct kvm_vcpu *vcpu)
static int __diag_virtio_hypercall(struct kvm_vcpu *vcpu)
{
int ret, idx;
+ long cookie;
/* No virtio-ccw notification? Get out quickly. */
if (!vcpu->kvm->arch.css_support ||
(vcpu->run->s.regs.gprs[1] != KVM_S390_VIRTIO_CCW_NOTIFY))
return -EOPNOTSUPP;
+ cookie = vcpu->run->s.regs.gprs[4];
idx = srcu_read_lock(&vcpu->kvm->srcu);
/*
* The layout is as follows:
* - gpr 2 contains the subchannel id (passed as addr)
* - gpr 3 contains the virtqueue index (passed as datamatch)
+ * - gpr 4 contains the index on the bus (optionally)
*/
- ret = kvm_io_bus_write(vcpu->kvm, KVM_VIRTIO_CCW_NOTIFY_BUS,
- vcpu->run->s.regs.gprs[2],
- 8, &vcpu->run->s.regs.gprs[3]);
+ ret = kvm_io_bus_write_cookie(vcpu->kvm, KVM_VIRTIO_CCW_NOTIFY_BUS,
+ vcpu->run->s.regs.gprs[2],
+ 8, &vcpu->run->s.regs.gprs[3],
+ &cookie);
srcu_read_unlock(&vcpu->kvm->srcu, idx);
+ if (!ret)
+ /* Return cookie in gpr 2. */
+ vcpu->run->s.regs.gprs[2] = cookie;
/* kvm_io_bus_write returns -EOPNOTSUPP if it found no match. */
return ret < 0 ? ret : 0;
}
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 206247f..2f65a3a 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -154,6 +154,8 @@ enum kvm_bus {
int kvm_io_bus_write(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
int len, const void *val);
+int kvm_io_bus_write_cookie(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
+ int len, const void *val, long *cookie);
int kvm_io_bus_read(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, int len,
void *val);
int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 7c188a3..b77ea5f 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2710,6 +2710,51 @@ int kvm_io_bus_write(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
return -EOPNOTSUPP;
}
+/* kvm_io_bus_write_cookie - called under kvm->slots_lock */
+int kvm_io_bus_write_cookie(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
+ int len, const void *val, long *cookie)
+{
+ int idx, ret = -EOPNOTSUPP;
+ struct kvm_io_bus *bus;
+ struct kvm_io_range range;
+
+ range = (struct kvm_io_range) {
+ .addr = addr,
+ .len = len,
+ };
+
+ if (!cookie)
+ return -EINVAL;
+
+ bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu);
+
+ /* First try the device referenced by *cookie. */
+ if (kvm_io_bus_sort_cmp(&range, &bus->range[*cookie]) == 0)
+ if (!kvm_iodevice_write(bus->range[*cookie].dev, addr, len,
+ val))
+ return 0;
+
+ /*
+ * *cookie contained garbage; fall back to search and return the
+ * correct value in *cookie.
+ */
+ idx = kvm_io_bus_get_first_dev(bus, addr, len);
+ if (idx < 0)
+ goto out;
+
+ while (idx < bus->dev_count &&
+ kvm_io_bus_sort_cmp(&range, &bus->range[idx]) == 0) {
+ if (!kvm_iodevice_write(bus->range[idx].dev, addr, len, val)) {
+ ret = 0;
+ goto out;
+ }
+ idx++;
+ }
+out:
+ *cookie = idx;
+ return ret;
+}
+
/* kvm_io_bus_read - called under kvm->slots_lock */
int kvm_io_bus_read(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
int len, void *val)
^ permalink raw reply related [flat|nested] 13+ messages in thread* Re: [PATCH v5 6/6] KVM: s390: Wire up ioeventfd.
2013-03-05 8:13 ` Cornelia Huck
@ 2013-03-05 13:19 ` Michael S. Tsirkin
2013-03-05 14:24 ` Cornelia Huck
0 siblings, 1 reply; 13+ messages in thread
From: Michael S. Tsirkin @ 2013-03-05 13:19 UTC (permalink / raw)
To: Cornelia Huck
Cc: Carsten Otte, KVM, Gleb Natapov, linux-s390, Marcelo Tosatti,
Heiko Carstens, Alexander Graf, qemu-devel, Christian Borntraeger,
Martin Schwidefsky
On Tue, Mar 05, 2013 at 09:13:08AM +0100, Cornelia Huck wrote:
> On Mon, 4 Mar 2013 21:07:41 -0300
> Marcelo Tosatti <mtosatti@redhat.com> wrote:
>
> > On Thu, Feb 28, 2013 at 12:33:21PM +0100, Cornelia Huck wrote:
> > > Enable ioeventfd support on s390 and hook up diagnose 500 virtio-ccw
> > > notifications.
> > >
> > > Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
> > > ---
> > > arch/s390/kvm/Kconfig | 1 +
> > > arch/s390/kvm/Makefile | 2 +-
> > > arch/s390/kvm/diag.c | 26 ++++++++++++++++++++++++++
> > > arch/s390/kvm/kvm-s390.c | 1 +
> > > 4 files changed, 29 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/arch/s390/kvm/Kconfig b/arch/s390/kvm/Kconfig
> > > index b58dd86..3c43e30 100644
> > > --- a/arch/s390/kvm/Kconfig
> > > +++ b/arch/s390/kvm/Kconfig
> > > @@ -22,6 +22,7 @@ config KVM
> > > select PREEMPT_NOTIFIERS
> > > select ANON_INODES
> > > select HAVE_KVM_CPU_RELAX_INTERCEPT
> > > + select HAVE_KVM_EVENTFD
> > > ---help---
> > > Support hosting paravirtualized guest machines using the SIE
> > > virtualization capability on the mainframe. This should work
> > > diff --git a/arch/s390/kvm/Makefile b/arch/s390/kvm/Makefile
> > > index 3975722..8fe9d65 100644
> > > --- a/arch/s390/kvm/Makefile
> > > +++ b/arch/s390/kvm/Makefile
> > > @@ -6,7 +6,7 @@
> > > # it under the terms of the GNU General Public License (version 2 only)
> > > # as published by the Free Software Foundation.
> > >
> > > -common-objs = $(addprefix ../../../virt/kvm/, kvm_main.o)
> > > +common-objs = $(addprefix ../../../virt/kvm/, kvm_main.o eventfd.o)
> > >
> > > ccflags-y := -Ivirt/kvm -Iarch/s390/kvm
> > >
> > > diff --git a/arch/s390/kvm/diag.c b/arch/s390/kvm/diag.c
> > > index a390687..1c01a99 100644
> > > --- a/arch/s390/kvm/diag.c
> > > +++ b/arch/s390/kvm/diag.c
> > > @@ -13,6 +13,7 @@
> > >
> > > #include <linux/kvm.h>
> > > #include <linux/kvm_host.h>
> > > +#include <asm/virtio-ccw.h>
> > > #include "kvm-s390.h"
> > > #include "trace.h"
> > > #include "trace-s390.h"
> > > @@ -104,6 +105,29 @@ static int __diag_ipl_functions(struct kvm_vcpu *vcpu)
> > > return -EREMOTE;
> > > }
> > >
> > > +static int __diag_virtio_hypercall(struct kvm_vcpu *vcpu)
> > > +{
> > > + int ret, idx;
> > > +
> > > + /* No virtio-ccw notification? Get out quickly. */
> > > + if (!vcpu->kvm->arch.css_support ||
> > > + (vcpu->run->s.regs.gprs[1] != KVM_S390_VIRTIO_CCW_NOTIFY))
> > > + return -EOPNOTSUPP;
> > > +
> > > + idx = srcu_read_lock(&vcpu->kvm->srcu);
> > > + /*
> > > + * The layout is as follows:
> > > + * - gpr 2 contains the subchannel id (passed as addr)
> > > + * - gpr 3 contains the virtqueue index (passed as datamatch)
> > > + */
> > > + ret = kvm_io_bus_write(vcpu->kvm, KVM_VIRTIO_CCW_NOTIFY_BUS,
> > > + vcpu->run->s.regs.gprs[2],
> > > + 8, &vcpu->run->s.regs.gprs[3]);
> > > + srcu_read_unlock(&vcpu->kvm->srcu, idx);
> > > + /* kvm_io_bus_write returns -EOPNOTSUPP if it found no match. */
> > > + return ret < 0 ? ret : 0;
> > > +}
> > > +
> >
> > What about the cookie?
>
> This is the not-performance-optimized version which went through our
> testing and which I'd like to see applied. I also have a not-yet-tested
> patch that adds cookie support (see below), but I'd like to postpone
> this to 3.10.
I agree it's best to delay this optimization, focus on basic
functionality now. As guest with cookie support is
compatible with host without said support (all we do
really is reserve a gpr), there won't be issues adding it later.
Some comments on the draft below.
> commit 8fce4a8a3478252f7ee2eb74d2732673f5911120
> Author: Cornelia Huck <cornelia.huck@de.ibm.com>
> Date: Tue Feb 26 17:05:01 2013 +0100
>
> virtio-ccw: ioeventfd: use cookies
>
> Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
>
> diff --git a/arch/s390/kvm/diag.c b/arch/s390/kvm/diag.c
> index 1c01a99..bd2a013 100644
> --- a/arch/s390/kvm/diag.c
> +++ b/arch/s390/kvm/diag.c
> @@ -108,22 +108,29 @@ static int __diag_ipl_functions(struct kvm_vcpu *vcpu)
> static int __diag_virtio_hypercall(struct kvm_vcpu *vcpu)
> {
> int ret, idx;
> + long cookie;
>
> /* No virtio-ccw notification? Get out quickly. */
> if (!vcpu->kvm->arch.css_support ||
> (vcpu->run->s.regs.gprs[1] != KVM_S390_VIRTIO_CCW_NOTIFY))
> return -EOPNOTSUPP;
>
> + cookie = vcpu->run->s.regs.gprs[4];
Hmm signed so this can become negative.
> idx = srcu_read_lock(&vcpu->kvm->srcu);
> /*
> * The layout is as follows:
> * - gpr 2 contains the subchannel id (passed as addr)
> * - gpr 3 contains the virtqueue index (passed as datamatch)
> + * - gpr 4 contains the index on the bus (optionally)
> */
> - ret = kvm_io_bus_write(vcpu->kvm, KVM_VIRTIO_CCW_NOTIFY_BUS,
> - vcpu->run->s.regs.gprs[2],
> - 8, &vcpu->run->s.regs.gprs[3]);
> + ret = kvm_io_bus_write_cookie(vcpu->kvm, KVM_VIRTIO_CCW_NOTIFY_BUS,
> + vcpu->run->s.regs.gprs[2],
> + 8, &vcpu->run->s.regs.gprs[3],
> + &cookie);
> srcu_read_unlock(&vcpu->kvm->srcu, idx);
> + if (!ret)
> + /* Return cookie in gpr 2. */
> + vcpu->run->s.regs.gprs[2] = cookie;
We should also set gprs[2] to something sane if exiting to userspace
so avoid adding overhead for that case.
Probably # of devices + 1 or a negative value.
Are there 32 bit guests? If yes can they pass a negative value?
> /* kvm_io_bus_write returns -EOPNOTSUPP if it found no match. */
> return ret < 0 ? ret : 0;
> }
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index 206247f..2f65a3a 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -154,6 +154,8 @@ enum kvm_bus {
>
> int kvm_io_bus_write(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
> int len, const void *val);
> +int kvm_io_bus_write_cookie(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
> + int len, const void *val, long *cookie);
> int kvm_io_bus_read(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, int len,
> void *val);
> int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index 7c188a3..b77ea5f 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -2710,6 +2710,51 @@ int kvm_io_bus_write(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
> return -EOPNOTSUPP;
> }
>
> +/* kvm_io_bus_write_cookie - called under kvm->slots_lock */
> +int kvm_io_bus_write_cookie(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
> + int len, const void *val, long *cookie)
> +{
> + int idx, ret = -EOPNOTSUPP;
> + struct kvm_io_bus *bus;
> + struct kvm_io_range range;
> +
> + range = (struct kvm_io_range) {
> + .addr = addr,
> + .len = len,
> + };
> +
> + if (!cookie)
> + return -EINVAL;
> +
Hmm does this ever trigger?
> + bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu);
> +
> + /* First try the device referenced by *cookie. */
> + if (kvm_io_bus_sort_cmp(&range, &bus->range[*cookie]) == 0)
We need to range-check the cookie.
> + if (!kvm_iodevice_write(bus->range[*cookie].dev, addr, len,
> + val))
> + return 0;
> +
> + /*
> + * *cookie contained garbage; fall back to search and return the
> + * correct value in *cookie.
> + */
> + idx = kvm_io_bus_get_first_dev(bus, addr, len);
> + if (idx < 0)
> + goto out;
> +
> + while (idx < bus->dev_count &&
> + kvm_io_bus_sort_cmp(&range, &bus->range[idx]) == 0) {
> + if (!kvm_iodevice_write(bus->range[idx].dev, addr, len, val)) {
> + ret = 0;
> + goto out;
> + }
> + idx++;
> + }
> +out:
> + *cookie = idx;
> + return ret;
> +}
> +
> /* kvm_io_bus_read - called under kvm->slots_lock */
> int kvm_io_bus_read(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
> int len, void *val)
^ permalink raw reply [flat|nested] 13+ messages in thread* Re: [PATCH v5 6/6] KVM: s390: Wire up ioeventfd.
2013-03-05 13:19 ` Michael S. Tsirkin
@ 2013-03-05 14:24 ` Cornelia Huck
0 siblings, 0 replies; 13+ messages in thread
From: Cornelia Huck @ 2013-03-05 14:24 UTC (permalink / raw)
To: Michael S. Tsirkin
Cc: Marcelo Tosatti, Gleb Natapov, Christian Borntraeger,
Carsten Otte, Alexander Graf, Heiko Carstens, Martin Schwidefsky,
KVM, linux-s390, qemu-devel
On Tue, 5 Mar 2013 15:19:43 +0200
"Michael S. Tsirkin" <mst@redhat.com> wrote:
> On Tue, Mar 05, 2013 at 09:13:08AM +0100, Cornelia Huck wrote:
> > On Mon, 4 Mar 2013 21:07:41 -0300
> > Marcelo Tosatti <mtosatti@redhat.com> wrote:
> >
> > > On Thu, Feb 28, 2013 at 12:33:21PM +0100, Cornelia Huck wrote:
> > > > Enable ioeventfd support on s390 and hook up diagnose 500 virtio-ccw
> > > > notifications.
> > > >
> > > > Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
> > > > ---
> > > > arch/s390/kvm/Kconfig | 1 +
> > > > arch/s390/kvm/Makefile | 2 +-
> > > > arch/s390/kvm/diag.c | 26 ++++++++++++++++++++++++++
> > > > arch/s390/kvm/kvm-s390.c | 1 +
> > > > 4 files changed, 29 insertions(+), 1 deletion(-)
> > > >
> > > > diff --git a/arch/s390/kvm/Kconfig b/arch/s390/kvm/Kconfig
> > > > index b58dd86..3c43e30 100644
> > > > --- a/arch/s390/kvm/Kconfig
> > > > +++ b/arch/s390/kvm/Kconfig
> > > > @@ -22,6 +22,7 @@ config KVM
> > > > select PREEMPT_NOTIFIERS
> > > > select ANON_INODES
> > > > select HAVE_KVM_CPU_RELAX_INTERCEPT
> > > > + select HAVE_KVM_EVENTFD
> > > > ---help---
> > > > Support hosting paravirtualized guest machines using the SIE
> > > > virtualization capability on the mainframe. This should work
> > > > diff --git a/arch/s390/kvm/Makefile b/arch/s390/kvm/Makefile
> > > > index 3975722..8fe9d65 100644
> > > > --- a/arch/s390/kvm/Makefile
> > > > +++ b/arch/s390/kvm/Makefile
> > > > @@ -6,7 +6,7 @@
> > > > # it under the terms of the GNU General Public License (version 2 only)
> > > > # as published by the Free Software Foundation.
> > > >
> > > > -common-objs = $(addprefix ../../../virt/kvm/, kvm_main.o)
> > > > +common-objs = $(addprefix ../../../virt/kvm/, kvm_main.o eventfd.o)
> > > >
> > > > ccflags-y := -Ivirt/kvm -Iarch/s390/kvm
> > > >
> > > > diff --git a/arch/s390/kvm/diag.c b/arch/s390/kvm/diag.c
> > > > index a390687..1c01a99 100644
> > > > --- a/arch/s390/kvm/diag.c
> > > > +++ b/arch/s390/kvm/diag.c
> > > > @@ -13,6 +13,7 @@
> > > >
> > > > #include <linux/kvm.h>
> > > > #include <linux/kvm_host.h>
> > > > +#include <asm/virtio-ccw.h>
> > > > #include "kvm-s390.h"
> > > > #include "trace.h"
> > > > #include "trace-s390.h"
> > > > @@ -104,6 +105,29 @@ static int __diag_ipl_functions(struct kvm_vcpu *vcpu)
> > > > return -EREMOTE;
> > > > }
> > > >
> > > > +static int __diag_virtio_hypercall(struct kvm_vcpu *vcpu)
> > > > +{
> > > > + int ret, idx;
> > > > +
> > > > + /* No virtio-ccw notification? Get out quickly. */
> > > > + if (!vcpu->kvm->arch.css_support ||
> > > > + (vcpu->run->s.regs.gprs[1] != KVM_S390_VIRTIO_CCW_NOTIFY))
> > > > + return -EOPNOTSUPP;
> > > > +
> > > > + idx = srcu_read_lock(&vcpu->kvm->srcu);
> > > > + /*
> > > > + * The layout is as follows:
> > > > + * - gpr 2 contains the subchannel id (passed as addr)
> > > > + * - gpr 3 contains the virtqueue index (passed as datamatch)
> > > > + */
> > > > + ret = kvm_io_bus_write(vcpu->kvm, KVM_VIRTIO_CCW_NOTIFY_BUS,
> > > > + vcpu->run->s.regs.gprs[2],
> > > > + 8, &vcpu->run->s.regs.gprs[3]);
> > > > + srcu_read_unlock(&vcpu->kvm->srcu, idx);
> > > > + /* kvm_io_bus_write returns -EOPNOTSUPP if it found no match. */
> > > > + return ret < 0 ? ret : 0;
> > > > +}
> > > > +
> > >
> > > What about the cookie?
> >
> > This is the not-performance-optimized version which went through our
> > testing and which I'd like to see applied. I also have a not-yet-tested
> > patch that adds cookie support (see below), but I'd like to postpone
> > this to 3.10.
>
> I agree it's best to delay this optimization, focus on basic
> functionality now. As guest with cookie support is
> compatible with host without said support (all we do
> really is reserve a gpr), there won't be issues adding it later.
> Some comments on the draft below.
>
>
> > commit 8fce4a8a3478252f7ee2eb74d2732673f5911120
> > Author: Cornelia Huck <cornelia.huck@de.ibm.com>
> > Date: Tue Feb 26 17:05:01 2013 +0100
> >
> > virtio-ccw: ioeventfd: use cookies
> >
> > Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
> >
> > diff --git a/arch/s390/kvm/diag.c b/arch/s390/kvm/diag.c
> > index 1c01a99..bd2a013 100644
> > --- a/arch/s390/kvm/diag.c
> > +++ b/arch/s390/kvm/diag.c
> > @@ -108,22 +108,29 @@ static int __diag_ipl_functions(struct kvm_vcpu *vcpu)
> > static int __diag_virtio_hypercall(struct kvm_vcpu *vcpu)
> > {
> > int ret, idx;
> > + long cookie;
> >
> > /* No virtio-ccw notification? Get out quickly. */
> > if (!vcpu->kvm->arch.css_support ||
> > (vcpu->run->s.regs.gprs[1] != KVM_S390_VIRTIO_CCW_NOTIFY))
> > return -EOPNOTSUPP;
> >
> > + cookie = vcpu->run->s.regs.gprs[4];
>
> Hmm signed so this can become negative.
>
> > idx = srcu_read_lock(&vcpu->kvm->srcu);
> > /*
> > * The layout is as follows:
> > * - gpr 2 contains the subchannel id (passed as addr)
> > * - gpr 3 contains the virtqueue index (passed as datamatch)
> > + * - gpr 4 contains the index on the bus (optionally)
> > */
> > - ret = kvm_io_bus_write(vcpu->kvm, KVM_VIRTIO_CCW_NOTIFY_BUS,
> > - vcpu->run->s.regs.gprs[2],
> > - 8, &vcpu->run->s.regs.gprs[3]);
> > + ret = kvm_io_bus_write_cookie(vcpu->kvm, KVM_VIRTIO_CCW_NOTIFY_BUS,
> > + vcpu->run->s.regs.gprs[2],
> > + 8, &vcpu->run->s.regs.gprs[3],
> > + &cookie);
> > srcu_read_unlock(&vcpu->kvm->srcu, idx);
> > + if (!ret)
> > + /* Return cookie in gpr 2. */
> > + vcpu->run->s.regs.gprs[2] = cookie;
>
> We should also set gprs[2] to something sane if exiting to userspace
> so avoid adding overhead for that case.
> Probably # of devices + 1 or a negative value.
Negative value would probably be the most obvious.
> Are there 32 bit guests? If yes can they pass a negative value?
No, we only support 64 bit guests.
>
> > /* kvm_io_bus_write returns -EOPNOTSUPP if it found no match. */
> > return ret < 0 ? ret : 0;
> > }
> > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> > index 206247f..2f65a3a 100644
> > --- a/include/linux/kvm_host.h
> > +++ b/include/linux/kvm_host.h
> > @@ -154,6 +154,8 @@ enum kvm_bus {
> >
> > int kvm_io_bus_write(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
> > int len, const void *val);
> > +int kvm_io_bus_write_cookie(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
> > + int len, const void *val, long *cookie);
> > int kvm_io_bus_read(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, int len,
> > void *val);
> > int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
> > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> > index 7c188a3..b77ea5f 100644
> > --- a/virt/kvm/kvm_main.c
> > +++ b/virt/kvm/kvm_main.c
> > @@ -2710,6 +2710,51 @@ int kvm_io_bus_write(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
> > return -EOPNOTSUPP;
> > }
> >
> > +/* kvm_io_bus_write_cookie - called under kvm->slots_lock */
> > +int kvm_io_bus_write_cookie(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
> > + int len, const void *val, long *cookie)
> > +{
> > + int idx, ret = -EOPNOTSUPP;
> > + struct kvm_io_bus *bus;
> > + struct kvm_io_range range;
> > +
> > + range = (struct kvm_io_range) {
> > + .addr = addr,
> > + .len = len,
> > + };
> > +
> > + if (!cookie)
> > + return -EINVAL;
> > +
>
> Hmm does this ever trigger?
Probably not.
>
> > + bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu);
> > +
> > + /* First try the device referenced by *cookie. */
> > + if (kvm_io_bus_sort_cmp(&range, &bus->range[*cookie]) == 0)
>
> We need to range-check the cookie.
Yup.
>
> > + if (!kvm_iodevice_write(bus->range[*cookie].dev, addr, len,
> > + val))
> > + return 0;
> > +
> > + /*
> > + * *cookie contained garbage; fall back to search and return the
> > + * correct value in *cookie.
> > + */
> > + idx = kvm_io_bus_get_first_dev(bus, addr, len);
> > + if (idx < 0)
> > + goto out;
> > +
> > + while (idx < bus->dev_count &&
> > + kvm_io_bus_sort_cmp(&range, &bus->range[idx]) == 0) {
> > + if (!kvm_iodevice_write(bus->range[idx].dev, addr, len, val)) {
> > + ret = 0;
> > + goto out;
> > + }
> > + idx++;
> > + }
> > +out:
> > + *cookie = idx;
> > + return ret;
> > +}
> > +
> > /* kvm_io_bus_read - called under kvm->slots_lock */
> > int kvm_io_bus_read(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
> > int len, void *val)
>
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v5 0/6] kvm: Make ioeventfd usable on s390.
2013-02-28 11:33 [PATCH v5 0/6] kvm: Make ioeventfd usable on s390 Cornelia Huck
` (5 preceding siblings ...)
2013-02-28 11:33 ` [PATCH v5 6/6] KVM: s390: Wire up ioeventfd Cornelia Huck
@ 2013-02-28 13:12 ` Michael S. Tsirkin
2013-03-05 22:14 ` Marcelo Tosatti
7 siblings, 0 replies; 13+ messages in thread
From: Michael S. Tsirkin @ 2013-02-28 13:12 UTC (permalink / raw)
To: Cornelia Huck
Cc: Carsten Otte, KVM, Gleb Natapov, linux-s390, Marcelo Tosatti,
Heiko Carstens, Alexander Graf, qemu-devel, Christian Borntraeger,
Martin Schwidefsky
On Thu, Feb 28, 2013 at 12:33:15PM +0100, Cornelia Huck wrote:
> v5 of the ioeventfd patch set, this time with a proper return code
> from __diag_virtio_hypercall(), otherwise unchanged.
>
> v4 -> v5:
> - Proper return code in __diag_virtio_hypercall()
> v3 -> v4:
> - Pass cookies in virtio-ccw notify hypercall
> - Coding style
> v2 -> v3:
> - Added a patch exporting the virtio-ccw api and use it for the
> diagnose implementation.
> - Better naming: We're dealing with virtio-ccw notifications only.
> v1 -> v2:
> - Move irqfd initialization from a module init function to kvm_init,
> eliminating the need for a second module for kvm/s390.
> - Use kvm_io_device for s390 css devices.
The patches look obviously correct to me.
I take no strong position on whether the userspace interface
and the addition of virtio-specific bits in s390 kvm are
acceptable, but looks ok to me too.
Acked-by: Michael S. Tsirkin <mst@redhat.com>
> Cornelia Huck (5):
> KVM: s390: Export virtio-ccw api.
> KVM: Initialize irqfd from kvm_init().
> KVM: Introduce KVM_VIRTIO_CCW_NOTIFY_BUS.
> KVM: ioeventfd for virtio-ccw devices.
> KVM: s390: Wire up ioeventfd.
>
> Michael S. Tsirkin (1):
> virtio_ccw: pass a cookie value to kvm hypercall
>
> Documentation/virtual/kvm/api.txt | 8 ++++++++
> arch/s390/include/uapi/asm/Kbuild | 1 +
> arch/s390/include/uapi/asm/virtio-ccw.h | 21 +++++++++++++++++++++
> arch/s390/kvm/Kconfig | 1 +
> arch/s390/kvm/Makefile | 2 +-
> arch/s390/kvm/diag.c | 26 ++++++++++++++++++++++++++
> arch/s390/kvm/kvm-s390.c | 1 +
> drivers/s390/kvm/virtio_ccw.c | 16 +++++++++-------
> include/linux/kvm_host.h | 14 ++++++++++++++
> include/uapi/linux/kvm.h | 3 +++
> virt/kvm/eventfd.c | 24 +++++++++++++++---------
> virt/kvm/kvm_main.c | 6 ++++++
> 12 files changed, 106 insertions(+), 17 deletions(-)
> create mode 100644 arch/s390/include/uapi/asm/virtio-ccw.h
>
> --
> 1.7.12.4
^ permalink raw reply [flat|nested] 13+ messages in thread* Re: [PATCH v5 0/6] kvm: Make ioeventfd usable on s390.
2013-02-28 11:33 [PATCH v5 0/6] kvm: Make ioeventfd usable on s390 Cornelia Huck
` (6 preceding siblings ...)
2013-02-28 13:12 ` [PATCH v5 0/6] kvm: Make ioeventfd usable on s390 Michael S. Tsirkin
@ 2013-03-05 22:14 ` Marcelo Tosatti
7 siblings, 0 replies; 13+ messages in thread
From: Marcelo Tosatti @ 2013-03-05 22:14 UTC (permalink / raw)
To: Cornelia Huck
Cc: Carsten Otte, KVM, Gleb Natapov, Michael S. Tsirkin, linux-s390,
Heiko Carstens, Alexander Graf, qemu-devel, Christian Borntraeger,
Martin Schwidefsky
On Thu, Feb 28, 2013 at 12:33:15PM +0100, Cornelia Huck wrote:
> v5 of the ioeventfd patch set, this time with a proper return code
> from __diag_virtio_hypercall(), otherwise unchanged.
>
> v4 -> v5:
> - Proper return code in __diag_virtio_hypercall()
> v3 -> v4:
> - Pass cookies in virtio-ccw notify hypercall
> - Coding style
> v2 -> v3:
> - Added a patch exporting the virtio-ccw api and use it for the
> diagnose implementation.
> - Better naming: We're dealing with virtio-ccw notifications only.
> v1 -> v2:
> - Move irqfd initialization from a module init function to kvm_init,
> eliminating the need for a second module for kvm/s390.
> - Use kvm_io_device for s390 css devices.
>
> Cornelia Huck (5):
> KVM: s390: Export virtio-ccw api.
> KVM: Initialize irqfd from kvm_init().
> KVM: Introduce KVM_VIRTIO_CCW_NOTIFY_BUS.
> KVM: ioeventfd for virtio-ccw devices.
> KVM: s390: Wire up ioeventfd.
>
> Michael S. Tsirkin (1):
> virtio_ccw: pass a cookie value to kvm hypercall
Applied, thanks.
^ permalink raw reply [flat|nested] 13+ messages in thread