On 2012-07-09 00:55, Michael S. Tsirkin wrote:
> On Mon, Jul 02, 2012 at 11:08:20AM -0600, Alex Williamson wrote:
>> On Mon, 2012-06-25 at 11:32 +0200, Jan Kiszka wrote:
>>> On 2012-06-11 13:19, Michael S. Tsirkin wrote:
>>>> We can deliver certain interrupts, notably MSIX,
>>>> from atomic context.
>>>> Here's an untested patch to do this (compiled only).
>>>>
>>>> Changes from v2:
>>>> Don't inject broadcast interrupts directly
>>>> Changes from v1:
>>>> Tried to address comments from v1, except unifying
>>>> with kvm_set_irq: passing flags to it looks too ugly.
>>>> Added a comment.
>>>>
>>>> Jan, you said you can test this?
>>>>
>>>>
>>>> Michael S. Tsirkin (2):
>>>> kvm: implement kvm_set_msi_inatomic
>>>> kvm: deliver msix interrupts from irq handler
>>>>
>>>> include/linux/kvm_host.h | 3 ++
>>>> virt/kvm/assigned-dev.c | 31 ++++++++++++++++++--
>>>> virt/kvm/irq_comm.c | 75 ++++++++++++++++++++++++++++++++++++++++++++----
>>>> 3 files changed, 102 insertions(+), 7 deletions(-)
>>>>
>>>
>>> Finally-tested-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
>>
>> Michael, we need either this or the simple oneshot patch to get device
>> assignment working again for 3.5. Are you planning to push this for
>> 3.5? Thanks,
>>
>> Alex
>>
>
> Avi wants this reworked using an injection cache. I agree with Jan
> though: oneshot looks too ugly. Just so you can make progress, can't we
> add a stub handler returning IRQ_WAKE_THREAD unconditionally for now?
> I.e. like the below (warning: completely untested).
>
> Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
>
> --
>
> diff --git a/virt/kvm/assigned-dev.c b/virt/kvm/assigned-dev.c
> index b1e091a..18cc36e 100644
> --- a/virt/kvm/assigned-dev.c
> +++ b/virt/kvm/assigned-dev.c
> @@ -334,6 +334,11 @@ static int assigned_device_enable_host_intx(struct kvm *kvm,
> }
>
> #ifdef __KVM_HAVE_MSI
> +static irqreturn_t kvm_assigned_dev_msi(int irq, void *dev_id)
> +{
> + return IRQ_WAKE_THREAD;
> +}
> +
> static int assigned_device_enable_host_msi(struct kvm *kvm,
> struct kvm_assigned_dev_kernel *dev)
> {
> @@ -346,7 +351,7 @@ static int assigned_device_enable_host_msi(struct kvm *kvm,
> }
>
> dev->host_irq = dev->dev->irq;
> - if (request_threaded_irq(dev->host_irq, NULL,
> + if (request_threaded_irq(dev->host_irq, kvm_assigned_dev_msi,
> kvm_assigned_dev_thread_msi, 0,
> dev->irq_name, dev)) {
> pci_disable_msi(dev->dev);
> @@ -358,6 +363,11 @@ static int assigned_device_enable_host_msi(struct kvm *kvm,
> #endif
>
> #ifdef __KVM_HAVE_MSIX
> +static irqreturn_t kvm_assigned_dev_msix(int irq, void *dev_id)
> +{
> + return IRQ_WAKE_THREAD;
> +}
> +
> static int assigned_device_enable_host_msix(struct kvm *kvm,
> struct kvm_assigned_dev_kernel *dev)
> {
> @@ -374,7 +384,8 @@ static int assigned_device_enable_host_msix(struct kvm *kvm,
>
> for (i = 0; i < dev->entries_nr; i++) {
> r = request_threaded_irq(dev->host_msix_entries[i].vector,
> - NULL, kvm_assigned_dev_thread_msix,
> + kvm_assigned_dev_msix,
> + kvm_assigned_dev_thread_msix,
> 0, dev->irq_name, dev);
> if (r)
> goto err;
>
Should restore the status quo before 3.5's IRQ layer changes. Looks ok
to me.
Jan
--
Siemens AG, Corporate Technology, CT RTC ITP SDP-DE
Corporate Competence Center Embedded Linux
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