Re: [RFC PATCH V2 09/10] Qemu/VFIO: Add SRIOV VF migration support

2015-12-03 Thread Lan, Tianyu 



On 12/3/2015 6:25 AM, Alex Williamson wrote:

On Tue, 2015-11-24 at 21:35 +0800, Lan Tianyu wrote:

This patch is to add SRIOV VF migration support.
Create new device type "vfio-sriov" and add faked PCI migration capability
to the type device.

The purpose of the new capability
1) sync migration status with VF driver in the VM
2) Get mailbox irq vector to notify VF driver during migration.
3) Provide a way to control injecting irq or not.

Qemu will migrate PCI configure space regs and MSIX config for VF.
Inject mailbox irq at last stage of migration to notify VF about
migration event and wait VF driver ready for migration. VF driver
writeS PCI config reg PCI_VF_MIGRATION_VF_STATUS in the new cap table
to tell Qemu.


What makes this sr-iov specific?  Why wouldn't we simply extend vfio-pci
with a migration=on feature?  Thanks,


Sounds reasonable and will update it.



Alex


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Re: [RFC PATCH V2 09/10] Qemu/VFIO: Add SRIOV VF migration support

2015-12-02 Thread Alex Williamson 
On Tue, 2015-11-24 at 21:35 +0800, Lan Tianyu wrote:
> This patch is to add SRIOV VF migration support.
> Create new device type "vfio-sriov" and add faked PCI migration capability
> to the type device.
> 
> The purpose of the new capability
> 1) sync migration status with VF driver in the VM
> 2) Get mailbox irq vector to notify VF driver during migration.
> 3) Provide a way to control injecting irq or not.
> 
> Qemu will migrate PCI configure space regs and MSIX config for VF.
> Inject mailbox irq at last stage of migration to notify VF about
> migration event and wait VF driver ready for migration. VF driver
> writeS PCI config reg PCI_VF_MIGRATION_VF_STATUS in the new cap table
> to tell Qemu.

What makes this sr-iov specific?  Why wouldn't we simply extend vfio-pci
with a migration=on feature?  Thanks,

Alex

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Re: [RFC PATCH V2 09/10] Qemu/VFIO: Add SRIOV VF migration support

2015-11-25 Thread Michael S. Tsirkin 
On Wed, Nov 25, 2015 at 11:32:23PM +0800, Lan, Tianyu wrote:
> 
> On 11/25/2015 5:03 AM, Michael S. Tsirkin wrote:
> >>>+void vfio_migration_cap_handle(PCIDevice *pdev, uint32_t addr,
> >>>+  uint32_t val, int len)
> >>>+{
> >>>+VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
> >>>+
> >>>+if (addr == vdev->migration_cap + PCI_VF_MIGRATION_VF_STATUS
> >>>+&& val == PCI_VF_READY_FOR_MIGRATION) {
> >>>+qemu_event_set(_event);
> >This would wake migration so it can proceed -
> >except it needs QEMU lock to run, and that's
> >taken by the migration thread.
> 
> Sorry, I seem to miss something.
> Which lock may cause dead lock when calling vfio_migration_cap_handle()
> and run migration?

qemu_global_mutex.

> The function is called when VF accesses faked PCI capability.
> 
> >
> >It seems unlikely that this ever worked - how
> >did you test this?
> >
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Re: [RFC PATCH V2 09/10] Qemu/VFIO: Add SRIOV VF migration support

2015-11-25 Thread Lan, Tianyu 


On 11/25/2015 5:03 AM, Michael S. Tsirkin wrote:

>+void vfio_migration_cap_handle(PCIDevice *pdev, uint32_t addr,
>+  uint32_t val, int len)
>+{
>+VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
>+
>+if (addr == vdev->migration_cap + PCI_VF_MIGRATION_VF_STATUS
>+&& val == PCI_VF_READY_FOR_MIGRATION) {
>+qemu_event_set(_event);

This would wake migration so it can proceed -
except it needs QEMU lock to run, and that's
taken by the migration thread.


Sorry, I seem to miss something.
Which lock may cause dead lock when calling vfio_migration_cap_handle()
and run migration?
The function is called when VF accesses faked PCI capability.



It seems unlikely that this ever worked - how
did you test this?


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Re: [RFC PATCH V2 09/10] Qemu/VFIO: Add SRIOV VF migration support

2015-11-24 Thread Michael S. Tsirkin 
On Tue, Nov 24, 2015 at 09:35:26PM +0800, Lan Tianyu wrote:
> This patch is to add SRIOV VF migration support.
> Create new device type "vfio-sriov" and add faked PCI migration capability
> to the type device.
> 
> The purpose of the new capability
> 1) sync migration status with VF driver in the VM
> 2) Get mailbox irq vector to notify VF driver during migration.
> 3) Provide a way to control injecting irq or not.
> 
> Qemu will migrate PCI configure space regs and MSIX config for VF.
> Inject mailbox irq at last stage of migration to notify VF about
> migration event and wait VF driver ready for migration.

I think this last bit "wait VF driver ready for migration"
is wrong. Not a lot is gained as compared to hotunplug.

To really get a benefit from this feature migration should
succeed even if guest is stuck, then interrupt should
tell guest that it has to reset the driver.


> VF driver
> writeS PCI config reg PCI_VF_MIGRATION_VF_STATUS in the new cap table
> to tell Qemu.
> 
> Signed-off-by: Lan Tianyu 
> ---
>  hw/vfio/Makefile.objs |   2 +-
>  hw/vfio/pci.c |   6 ++
>  hw/vfio/pci.h |   4 ++
>  hw/vfio/sriov.c   | 178 
> ++
>  4 files changed, 189 insertions(+), 1 deletion(-)
>  create mode 100644 hw/vfio/sriov.c
> 
> diff --git a/hw/vfio/Makefile.objs b/hw/vfio/Makefile.objs
> index d540c9d..9cf0178 100644
> --- a/hw/vfio/Makefile.objs
> +++ b/hw/vfio/Makefile.objs
> @@ -1,6 +1,6 @@
>  ifeq ($(CONFIG_LINUX), y)
>  obj-$(CONFIG_SOFTMMU) += common.o
> -obj-$(CONFIG_PCI) += pci.o
> +obj-$(CONFIG_PCI) += pci.o sriov.o
>  obj-$(CONFIG_SOFTMMU) += platform.o
>  obj-$(CONFIG_SOFTMMU) += calxeda-xgmac.o
>  endif
> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
> index 7c43fc1..e7583b5 100644
> --- a/hw/vfio/pci.c
> +++ b/hw/vfio/pci.c
> @@ -2013,6 +2013,11 @@ void vfio_pci_write_config(PCIDevice *pdev, uint32_t 
> addr,
>  } else if (was_enabled && !is_enabled) {
>  vfio_disable_msix(vdev);
>  }
> +} else if (vdev->migration_cap &&
> +ranges_overlap(addr, len, vdev->migration_cap, 0x10)) {
> +/* Write everything to QEMU to keep emulated bits correct */
> +pci_default_write_config(pdev, addr, val, len);
> +vfio_migration_cap_handle(pdev, addr, val, len);
>  } else {
>  /* Write everything to QEMU to keep emulated bits correct */
>  pci_default_write_config(pdev, addr, val, len);
> @@ -3517,6 +3522,7 @@ static int vfio_initfn(PCIDevice *pdev)
>  vfio_register_err_notifier(vdev);
>  vfio_register_req_notifier(vdev);
>  vfio_setup_resetfn(vdev);
> +vfio_add_migration_capability(vdev);
>  
>  return 0;
>  
> diff --git a/hw/vfio/pci.h b/hw/vfio/pci.h
> index 6c00575..ee6ca5e 100644
> --- a/hw/vfio/pci.h
> +++ b/hw/vfio/pci.h
> @@ -134,6 +134,7 @@ typedef struct VFIOPCIDevice {
>  PCIHostDeviceAddress host;
>  EventNotifier err_notifier;
>  EventNotifier req_notifier;
> +uint16_tmigration_cap;
>  int (*resetfn)(struct VFIOPCIDevice *);
>  uint32_t features;
>  #define VFIO_FEATURE_ENABLE_VGA_BIT 0
> @@ -162,3 +163,6 @@ uint32_t vfio_pci_read_config(PCIDevice *pdev, uint32_t 
> addr, int len);
>  void vfio_pci_write_config(PCIDevice *pdev, uint32_t addr,
> uint32_t val, int len);
>  void vfio_enable_msix(VFIOPCIDevice *vdev);
> +void vfio_add_migration_capability(VFIOPCIDevice *vdev);
> +void vfio_migration_cap_handle(PCIDevice *pdev, uint32_t addr,
> +   uint32_t val, int len);
> diff --git a/hw/vfio/sriov.c b/hw/vfio/sriov.c
> new file mode 100644
> index 000..3109538
> --- /dev/null
> +++ b/hw/vfio/sriov.c
> @@ -0,0 +1,178 @@
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +
> +#include "hw/hw.h"
> +#include "hw/vfio/pci.h"
> +#include "hw/vfio/vfio.h"
> +#include "hw/vfio/vfio-common.h"
> +
> +#define TYPE_VFIO_SRIOV "vfio-sriov"
> +
> +#define SRIOV_LM_SETUP 0x01
> +#define SRIOV_LM_COMPLETE 0x02
> +
> +QemuEvent migration_event;
> +
> +static void vfio_dev_post_load(void *opaque)
> +{
> +struct PCIDevice *pdev = (struct PCIDevice *)opaque;
> +VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
> +MSIMessage msg;
> +int vector;
> +
> +if (vfio_pci_read_config(pdev,
> +vdev->migration_cap + PCI_VF_MIGRATION_CAP, 1)
> +!= PCI_VF_MIGRATION_ENABLE)
> +return;
> +
> +vector = vfio_pci_read_config(pdev,
> +vdev->migration_cap + PCI_VF_MIGRATION_IRQ, 1);
> +
> +msg = msix_get_message(pdev, vector);
> +kvm_irqchip_send_msi(kvm_state, msg);
> +}
> +
> +static int vfio_dev_load(QEMUFile *f, void *opaque, int version_id)
> +{
> +struct PCIDevice *pdev = (struct PCIDevice *)opaque;
> +VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
> +int ret;
> +
> +

[RFC PATCH V2 09/10] Qemu/VFIO: Add SRIOV VF migration support

2015-11-24 Thread Lan Tianyu 
This patch is to add SRIOV VF migration support.
Create new device type "vfio-sriov" and add faked PCI migration capability
to the type device.

The purpose of the new capability
1) sync migration status with VF driver in the VM
2) Get mailbox irq vector to notify VF driver during migration.
3) Provide a way to control injecting irq or not.

Qemu will migrate PCI configure space regs and MSIX config for VF.
Inject mailbox irq at last stage of migration to notify VF about
migration event and wait VF driver ready for migration. VF driver
writeS PCI config reg PCI_VF_MIGRATION_VF_STATUS in the new cap table
to tell Qemu.

Signed-off-by: Lan Tianyu 
---
 hw/vfio/Makefile.objs |   2 +-
 hw/vfio/pci.c |   6 ++
 hw/vfio/pci.h |   4 ++
 hw/vfio/sriov.c   | 178 ++
 4 files changed, 189 insertions(+), 1 deletion(-)
 create mode 100644 hw/vfio/sriov.c

diff --git a/hw/vfio/Makefile.objs b/hw/vfio/Makefile.objs
index d540c9d..9cf0178 100644
--- a/hw/vfio/Makefile.objs
+++ b/hw/vfio/Makefile.objs
@@ -1,6 +1,6 @@
 ifeq ($(CONFIG_LINUX), y)
 obj-$(CONFIG_SOFTMMU) += common.o
-obj-$(CONFIG_PCI) += pci.o
+obj-$(CONFIG_PCI) += pci.o sriov.o
 obj-$(CONFIG_SOFTMMU) += platform.o
 obj-$(CONFIG_SOFTMMU) += calxeda-xgmac.o
 endif
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 7c43fc1..e7583b5 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -2013,6 +2013,11 @@ void vfio_pci_write_config(PCIDevice *pdev, uint32_t 
addr,
 } else if (was_enabled && !is_enabled) {
 vfio_disable_msix(vdev);
 }
+} else if (vdev->migration_cap &&
+ranges_overlap(addr, len, vdev->migration_cap, 0x10)) {
+/* Write everything to QEMU to keep emulated bits correct */
+pci_default_write_config(pdev, addr, val, len);
+vfio_migration_cap_handle(pdev, addr, val, len);
 } else {
 /* Write everything to QEMU to keep emulated bits correct */
 pci_default_write_config(pdev, addr, val, len);
@@ -3517,6 +3522,7 @@ static int vfio_initfn(PCIDevice *pdev)
 vfio_register_err_notifier(vdev);
 vfio_register_req_notifier(vdev);
 vfio_setup_resetfn(vdev);
+vfio_add_migration_capability(vdev);
 
 return 0;
 
diff --git a/hw/vfio/pci.h b/hw/vfio/pci.h
index 6c00575..ee6ca5e 100644
--- a/hw/vfio/pci.h
+++ b/hw/vfio/pci.h
@@ -134,6 +134,7 @@ typedef struct VFIOPCIDevice {
 PCIHostDeviceAddress host;
 EventNotifier err_notifier;
 EventNotifier req_notifier;
+uint16_tmigration_cap;
 int (*resetfn)(struct VFIOPCIDevice *);
 uint32_t features;
 #define VFIO_FEATURE_ENABLE_VGA_BIT 0
@@ -162,3 +163,6 @@ uint32_t vfio_pci_read_config(PCIDevice *pdev, uint32_t 
addr, int len);
 void vfio_pci_write_config(PCIDevice *pdev, uint32_t addr,
uint32_t val, int len);
 void vfio_enable_msix(VFIOPCIDevice *vdev);
+void vfio_add_migration_capability(VFIOPCIDevice *vdev);
+void vfio_migration_cap_handle(PCIDevice *pdev, uint32_t addr,
+   uint32_t val, int len);
diff --git a/hw/vfio/sriov.c b/hw/vfio/sriov.c
new file mode 100644
index 000..3109538
--- /dev/null
+++ b/hw/vfio/sriov.c
@@ -0,0 +1,178 @@
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+
+#include "hw/hw.h"
+#include "hw/vfio/pci.h"
+#include "hw/vfio/vfio.h"
+#include "hw/vfio/vfio-common.h"
+
+#define TYPE_VFIO_SRIOV "vfio-sriov"
+
+#define SRIOV_LM_SETUP 0x01
+#define SRIOV_LM_COMPLETE 0x02
+
+QemuEvent migration_event;
+
+static void vfio_dev_post_load(void *opaque)
+{
+struct PCIDevice *pdev = (struct PCIDevice *)opaque;
+VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
+MSIMessage msg;
+int vector;
+
+if (vfio_pci_read_config(pdev,
+vdev->migration_cap + PCI_VF_MIGRATION_CAP, 1)
+!= PCI_VF_MIGRATION_ENABLE)
+return;
+
+vector = vfio_pci_read_config(pdev,
+vdev->migration_cap + PCI_VF_MIGRATION_IRQ, 1);
+
+msg = msix_get_message(pdev, vector);
+kvm_irqchip_send_msi(kvm_state, msg);
+}
+
+static int vfio_dev_load(QEMUFile *f, void *opaque, int version_id)
+{
+struct PCIDevice *pdev = (struct PCIDevice *)opaque;
+VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
+int ret;
+
+if(qemu_get_byte(f)!= SRIOV_LM_COMPLETE)
+return 0;
+
+ret = pci_device_load(pdev, f);
+if (ret) {
+error_report("Faild to load PCI config space.\n");
+return ret;
+}
+
+if (msix_enabled(pdev)) {
+vfio_enable_msix(vdev);
+msix_load(pdev, f);
+}
+
+vfio_pci_write_config(pdev,vdev->migration_cap +
+PCI_VF_MIGRATION_VMM_STATUS, VMM_MIGRATION_END, 1);
+vfio_pci_write_config(pdev,vdev->migration_cap +
+PCI_VF_MIGRATION_VF_STATUS, PCI_VF_WAIT_FOR_MIGRATION, 1);
+return 0;
+}
+
+static int vfio_dev_save_complete(QEMUFile *f, void *opaque)
+{
+