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Re: [Qemu-devel] [PATCH 08/10] vfio: introduce last reset sequence id
From: |
Michael S. Tsirkin |
Subject: |
Re: [Qemu-devel] [PATCH 08/10] vfio: introduce last reset sequence id |
Date: |
Wed, 17 Feb 2016 17:56:58 +0200 |
On Wed, Feb 17, 2016 at 06:43:52PM +0800, Cao jin wrote:
> From: Chen Fan <address@hidden>
>
> avoid multi-reset host bus, we introduce sequence id to specify which
> bus is resetting. and if one of the dependent devices has done a reset.
> the others should skip.
>
> Signed-off-by: Chen Fan <address@hidden>
I don't see why it's needed. All devices on same bus always
undergo bus reset together. Just select a representative (e.g.
smallest devfn) and reset from that.
> ---
> hw/vfio/pci.c | 14 ++++++++++++++
> hw/vfio/pci.h | 3 +++
> 2 files changed, 17 insertions(+)
>
> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
> index b900f70..5b885e7 100644
> --- a/hw/vfio/pci.c
> +++ b/hw/vfio/pci.c
> @@ -1951,6 +1951,8 @@ static int vfio_check_host_bus_reset(VFIOPCIDevice
> *vdev)
> /* List all affected devices by bus reset */
> devices = &info->devices[0];
>
> + vdev->single_depend_dev = (info->count == 1);
> +
> /* Verify that we have all the groups required */
> for (i = 0; i < info->count; i++) {
> PCIHostDeviceAddress host;
> @@ -2283,6 +2285,7 @@ static int vfio_pci_hot_reset(VFIOPCIDevice *vdev, bool
> single)
>
> vfio_pci_pre_reset(vdev);
> vdev->vbasedev.needs_reset = false;
> + vdev->last_bus_reset_seqid = vdev->pdev.bus->reset_seqid;
>
> ret = vfio_get_hot_reset_info(vdev, &info);
> if (ret) {
> @@ -2344,6 +2347,7 @@ static int vfio_pci_hot_reset(VFIOPCIDevice *vdev, bool
> single)
> }
> vfio_pci_pre_reset(tmp);
> tmp->vbasedev.needs_reset = false;
> + tmp->last_bus_reset_seqid = vdev->pdev.bus->reset_seqid;
> multi = true;
> break;
> }
> @@ -3040,6 +3044,16 @@ static void vfio_pci_reset(DeviceState *dev)
>
> trace_vfio_pci_reset(vdev->vbasedev.name);
>
> + /* if need to do a hot reset */
> + if (pdev->bus->bus_in_reset) {
> + if (vdev->last_bus_reset_seqid == pdev->bus->reset_seqid) {
> + return;
> + } else if ((vdev->features & VFIO_FEATURE_ENABLE_AER)) {
> + vfio_pci_hot_reset(vdev, vdev->single_depend_dev);
> + return;
> + }
> + }
> +
> vfio_pci_pre_reset(vdev);
>
> if (vdev->resetfn && !vdev->resetfn(vdev)) {
> diff --git a/hw/vfio/pci.h b/hw/vfio/pci.h
> index bf9e93c..684931d 100644
> --- a/hw/vfio/pci.h
> +++ b/hw/vfio/pci.h
> @@ -144,6 +144,9 @@ typedef struct VFIOPCIDevice {
> bool no_kvm_msi;
> bool no_kvm_msix;
>
> + bool single_depend_dev;
> + uint32_t last_bus_reset_seqid;
> +
> NotifierWithReturn hotplug_notifier;
> } VFIOPCIDevice;
>
> --
> 1.9.3
>
>
- [Qemu-devel] [PATCH 00/10] vfio-pci: pass the aer error to guest, part2, Cao jin, 2016/02/17
- [Qemu-devel] [PATCH 01/10] vfio: extract vfio_get_hot_reset_info as a single function, Cao jin, 2016/02/17
- [Qemu-devel] [PATCH 02/10] vfio: squeeze out vfio_pci_do_hot_reset for support bus reset, Cao jin, 2016/02/17
- [Qemu-devel] [PATCH 03/10] vfio: add pcie extended capability support, Cao jin, 2016/02/17
- [Qemu-devel] [PATCH 04/10] vfio: add aer support for vfio device, Cao jin, 2016/02/17
- [Qemu-devel] [PATCH 05/10] vfio: add check host bus reset is support or not, Cao jin, 2016/02/17
- [Qemu-devel] [PATCH 06/10] add check reset mechanism when hotplug vfio device, Cao jin, 2016/02/17
- [Qemu-devel] [PATCH 08/10] vfio: introduce last reset sequence id, Cao jin, 2016/02/17
- Re: [Qemu-devel] [PATCH 08/10] vfio: introduce last reset sequence id,
Michael S. Tsirkin <=
- [Qemu-devel] [PATCH 07/10] pci: introduce pci bus pre reset, Cao jin, 2016/02/17
- [Qemu-devel] [PATCH 09/10] vfio-pci: pass the aer error to guest, Cao jin, 2016/02/17